I was a lecturer at Shanghai Jiaotong University during 2000-2002, then a post-doc researcher in a number of universities before I moved to the University of Pretoria in 2006, where I was appointed as a research fellow, a senior lecturer and eventually an associate professor. I moved to the University of Strathclyde in 2013, and then to UTS in 2016.
My current research interest is on smart grid related renewable energy, energy efficiency, and demand side management (DSM). I have also interest in energy efficiency performance evaluation, a field typically called measurement and verification. Completed or ongoing problems include distributed generation planning, solar thermal and PV efficiency; electric power dispatch; generator maintenance scheduling; operational efficiency improvement of industrial energy systems (pumps, conveyors, winders, and crushers); residential demand response; measurement and verification; building energy audit; electric vehicle battery system control; and nonlinear control systems amongst others. Being a Chartered Engineer, a Certified Energy Manager and a Certified Measurement and Verification Professional, I have extensive experience in the measurement and verification of more than 100 various types of energy efficiency projects: from power stations, lighting/heat pump/solar water heater mass roll out, to energy efficiency retrofit for buildings, furnaces, compressed air, pump stations, fans and ventilation systems, etc. Currently I am undertaking two research projects funded by the NSW government on the applications of renewable enregy in coal fired power plants and cotton farms. Anyone interested in the research and/or consulting services to the above topics is welcome to contact me!
- Member of the IFAC TC6.3 (Power and energy systems)
- Chartered Engineer
- Associate Editor for IET Renewabe Power Generation
- Associate Editor for IET Smart Grid
Can supervise: YES
Smart Grid, Renewable Energy, Energy Efficiency, and Demand Side Management
Most of my publications can be found from Google Scholar
Sun, Y, Yue, H, Zhang, J & Booth, C 2019, 'Minimisation of residential energy cost considering energy storage system and EV with driving usage probabilities', IEEE Transactions on Sustainable Energy.View/Download from: UTS OPUS or Publisher's site
Chen, G, Jin, Z, Liu, Y, Hu, Y, Zhang, J & Qing, X 2019, 'Programmable Topology Derivation of Integrated Three-Port DC-DC Converters with Reduced Switches for Low-Cost Applications', IEEE Transactions on Industrial Electronics.View/Download from: UTS OPUS or Publisher's site
IEEE Thanks to the favorable advantage of low cost, integrated three-port dc-dc converters with reduced switches have attracted extensive attention. In order to provide more new topologies, this paper aims to propose a programmable topology derivation method, which effectively simplifies the cumbersome process of the conventional combination method. Instead of the manual connection and examination, the proposed alternative can quickly and rigorously derive multiple viable integrated three-port dc-dc topologies from a great number of possible connections with the aid of computer program. Besides, generalized analysis is also accomplished, with which performance characteristics of all derived converters are simultaneously obtained and then a comprehensive comparison can be easily conducted to select a preferred one for the practical application. Finally, an example specific application with one input and two outputs is given, with topology selection, design and experimental results demonstrated in detail.
Lu, Z, Zhao, B, He, L, Zhang, D & Zhang, J 2019, 'Security level classification based on power system partitioning', IET Generation, Transmission and Distribution.View/Download from: UTS OPUS or Publisher's site
Ghadi, MJ, Ghavidel, S, Rajabi, A, Azizivahed, A, Li, L & Zhang, J 2019, 'A review on economic and technical operation of active distribution systems', RENEWABLE & SUSTAINABLE ENERGY REVIEWS, vol. 104, pp. 38-53.View/Download from: UTS OPUS or Publisher's site
Ghavidel Jirsaraie, S, Jabbari Ghadi, M, Vahed, AA, Aghaei, J, Li, L & Zhang, J 2019, 'Risk-Constrained Bidding Strategy for a Joint Operation of Wind Power and Compressed Air Energy Storage Aggregators', IEEE Transactions on Sustainable Energy, pp. 1-1.View/Download from: UTS OPUS or Publisher's site
Abbasi, MH, Taki, M, Rajabi, A, Li, L & Zhang, J 2019, 'Coordinated operation of electric vehicle charging and wind power generation as a virtual power plant: A multi-stage risk constrained approach', Applied Energy, pp. 1294-1307.View/Download from: UTS OPUS or Publisher's site
© 2019 Elsevier Ltd As the number of electric vehicles (EVs) is steadily increasing, their aggregation can offer significant storage to improve the electric system operation in many aspects. To this end, a comprehensive stochastic optimization framework is proposed in this paper for the joint operation of a fleet of EVs with a wind power producer (WPP) in a three-settlement pool-based market. An aggregator procures enough energy for the EVs based on their daily driving patterns, and schedules the stored energy to counterbalance WPP fluctuations. Different sources of uncertainty including the market prices and WPP generation are modeled through proper scenarios, and the risk is hedged by adding a risk measure to the formulation. To obtain more accurate results, the battery degradation costs are also included in the problem formulation. A detailed case study is presented based on the Iberian electricity market data as well as the technical information of three different types of EVs. The proposed approach is benchmarked against the disjoint operation of EVs and WPP. Numerical simulations demonstrate that the proposed strategy can effectively benefit EV owners and WPP by reducing the energy costs and increasing the profits.
He, L, Lu, Z, Pan, L, Zhao, H, Li, X & Zhang, J 2019, 'Optimal economic and emission dispatch of a microgrid with a combined heat and power system', Energies, vol. 12, no. 4.View/Download from: UTS OPUS or Publisher's site
© 2019 by the authors. With the rapid development of the new concept of energy internet, electric power systems often need to be investigated together with thermal energy systems. Additionally, to reduce pollution from gas emissions, it is very important to study the economic and emission dispatch of integrated electrical and heating systems. Hence, this paper proposes a multi-objective optimization dispatch model for a microgrid (MG) with a combined heat and power (CHP) system. This CHP-based MG system consists of a CHP unit, a wind turbine, a PV system, a fuel cell, an electric boiler, an electric storage, and a heat storage. It can exchange electricity with the distribution network and exchange heat with the district heating network. Minimum economic cost and minimum environmental cost are considered as the two objectives for the operation of this CHP-based MG system. To solve the two objective optimization problem, the multi-objective bacterial colony chemotaxis algorithm is utilized to obtain the Pareto optimal solution set, and the optimal solution is chosen by the Technique for Order of Preference by Similarity to Ideal Solution method. Finally, numerical case studies demonstrate the effectiveness of proposed model and method for the optimal economic and emission dispatch of the CHP-based MG system.
Dang, C, Zhang, J, Kwong, C-P & Li, L 2019, 'Demand Side Load Management for Big Industrial Energy Users under Blockchain-Based Peer-to-Peer Electricity Market', IEEE Transactions on Smart Grid.View/Download from: UTS OPUS or Publisher's site
Azizivahed, A, Arefi, A, Ghavidel Jirsaraie, S, Shafie-khah, M, Li, L, Zhang, J & Catalao, JPS 2019, 'Energy Management Strategy in Dynamic Distribution Network Reconfiguration considering Renewable Energy Resources and Storage', IEEE Transactions on Sustainable Energy, pp. 1-1.View/Download from: UTS OPUS or Publisher's site
Sharifian, A, Ghadi, MJ, Ghavidel, S, Li, L & Zhang, J 2018, 'A new method based on Type-2 fuzzy neural network for accurate wind power forecasting under uncertain data', Renewable Energy, vol. 120, pp. 220-230.View/Download from: UTS OPUS or Publisher's site
© 2017 Elsevier Ltd Nowadays, due to some environmental restrictions and decrease of fossil fuel sources, renewable energy sources and specifically wind power plants have a major part of energy generation in the industrial countries. To this end, the accurate forecasting of wind power is considered as an important and influential factor for the management and planning of power systems. In this paper, a novel intelligent method is proposed to provide an accurate forecast of the medium-term and long-term wind power by using the uncertain data from an online supervisory control and data acquisition (SCADA) system and the numerical weather prediction (NWP). This new method is based on the particle swarm optimization (PSO) algorithm and applied to train the Type-2 fuzzy neural network (T2FNN) which is called T2FNN-PSO. The presented method combines both of fuzzy system's expert knowledge and the neural network's learning capability for accurate forecasting of the wind power. In addition, the T2FNN-PSO can appropriately handle the uncertainties associated with the measured parameters from SCADA system, the numerical weather prediction and measuring tools. The proposed method is applied on a case study of a real wind farm. The obtained simulation results validate effectiveness and applicability of the proposed method for a practical solution to an accurate wind power forecasting in a power system control center.
He, L, Lu, Z, Zhang, J, Geng, L, Zhao, H & Li, X 2018, 'Low-carbon economic dispatch for electricity and natural gas systems considering carbon capture systems and power-to-gas', APPLIED ENERGY, vol. 224, pp. 357-370.View/Download from: UTS OPUS or Publisher's site
Sharifian, A, Sasansara, SF, Ghadi, MJ, Ghavidel, S, Li, L & Zhang, J 2018, 'Dynamic performance improvement of an ultra-lift Luo DC–DC converter by using a type-2 fuzzy neural controller', Computers and Electrical Engineering, vol. 69, pp. 171-182.View/Download from: UTS OPUS or Publisher's site
© 2018 Due to the uncertainty associated with the structure and electrical elements of DC–DC converters and the nonlinear performance of these modules, designing an effective controller is highly complicated and also technically challenging. This paper employs a new control approach based on type-2 fuzzy neural controller (T2FNC) in order to improve the dynamic response of an ultra-lift Luo DC–DC converter under different operational conditions. The proposed controller can rapidly stabilize the output voltage of converter to expected values by tuning the converter switching duty cycle. This controller can tackle the uncertainties associated with the structure of converters, measured control signals and measuring devices. Moreover, a new intelligent method based on firefly algorithm is applied to tune the parameters of T2FNC. In order to demonstrate the effectiveness of the proposed control approach, the proposed controller is compared to PI and fuzzy controllers under different operational conditions. Results validate efficiency of proposed T2FNC.
Liu, X, He, Y, Zeng, G, Zhang, J & Zheng, X 2018, 'State-of-Power Estimation of Li-Ion Batteries Considering the Battery Surface Temperature', Energy Technology, vol. 6, no. 7, pp. 1352-1360.View/Download from: UTS OPUS or Publisher's site
© 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim The state-of-power (SOP) of a Li-ion battery (LIB) is an important evaluation index for safety control and energy recovery in electric vehicles. Major state estimation methods are only applicable to fixed room temperature at 20 °C, although the battery capacity and resistance vary dramatically with a change in battery surface temperature in the working process of the battery. This causes significant errors in state estimation if only room temperature is assumed. The inaccurate state may cause further excessive current at high or low temperatures to affect safety and life cycle of the battery. Therefore, a novel state estimation method applicable to various battery surface temperatures is developed here. This method uses capacity–temperature and resistance–temperature relationships from experimental data to more accurately predict battery capacity and resistance over the full temperature range. It then applies the extended Kalman filter (EKF) technique to estimate the state-of-charge, and a method of constrained multi-parameter algorithm (CMPA) to estimate the SOP of LIBs. Simulation and experimental results show that the proposed method can obtain accurate SOP results at different temperatures.
Little is known about residential electricity demand in developing countries. In order to shed some light on this topic, this study combines data from South Africa's recent Income and Expenditure Survey with data from the National Energy Regulator of South Africa to estimate the determinants of residential energy demand. Combining electricity tariff data from the regulator with expenditure survey data from households provides an opportunity to explore the determinants of the demand for electricity. Due to the large number of zeroes in the dataset, a two-part model is employed. The results indicate that household income and electricity price are major demand determinants, and for the full two-part model, electricity demand is normal, as well as downward sloping, although inelastic in both cases; as expected, substitute fuel use impacts these elasticities. We also find that access to free basic electricity, a policy designed to improve access to electricity does what is expected. It is associated with increases in the probability that households purchase electricity and reduces total expenditure on electricity. Household demand is also higher for appliance-rich households in urban areas, especially if there are more household members and they live in larger dwellings.
Liu, X, Wan, Z, He, Y, Zheng, X, Zeng, G & Zhang, J 2018, 'A unified control strategy for inductor-based active battery equalisation schemes', Energies, vol. 11, no. 2.View/Download from: UTS OPUS or Publisher's site
© 2018 by the authors. Licensee MDPI, Basel, Switzerland. Series battery equalisation can improve battery charge and discharge reliability and extend battery life. Inductor-based battery equalisation schemes have the advantages of simple topologies and control strategies. According to the energy transfer pathway, inductor-based battery equalisation schemes can be divided into cell-to-cell and cell-to-pack equalisation schemes. The control strategies of the cell-to-cell schemes are simple; the inductor can only transfer energy between the neighbouring cells, so the equalisation speed is low. The cell-to-pack schemes are able to accomplish energy transfer between the cells and pack by charging and discharging the inductors. The equalisation speed is high, but the control strategies may be complex. In this paper, different equalisation topologies are reviewed, then a unified control strategy which is applicable to all of the inductor-based equalisation topologies is proposed. The equalisation speeds and efficiencies of these different schemes, including the newly-proposed unified control strategy, are analysed and compared. Based on the theoretical analysis, simulations, and experimental verifications, it is concluded that this unified control strategy can perform the battery equalisation process quickly and efficiently.
Azizivahed, A, Barani, M, Razavi, S-E, Ghavidel, S, Li, L & Zhang, J 2018, 'Energy storage management strategy in distribution networks utilised by photovoltaic resources', vol. 12, no. 21, pp. 5627-5638.View/Download from: UTS OPUS or Publisher's site
He, Y, Wan, Z, Liu, X, Zheng, X, Zeng, G & Zhang, J 2018, 'A cascaded multilevel converter based on SOC closed loop tracking', Progress In Electromagnetics Research C, vol. 88, pp. 103-115.View/Download from: UTS OPUS or Publisher's site
© 2018, Electromagnetics Academy. All rights reserved. This paper proposes a cascaded multilevel converter to reduce the number of IGBT switches for the purpose of improving system stability and decreasing switching losses. This converter can eliminate second-order ripple caused by energy exchange between grid and batteries, and thus extend battery life. This cascaded connection between the equivalent buck/boost circuit and the half-bridge inverter is also able to reduce the number of switch tubes. A control strategy based on state of charge (SOC) closed-loop tracking is designed to implement t0068e errorless follow-up control of average SOC values for electric vehicle batteries. The equivalent circuit under different working modes of the topology is analyzed, and the effectiveness of the control strategy is verified. Simulated and experimental results show that this converter can effectively achieve grid connection requirements and balance the battery units to meet practical needs.
Lu, Z, Zhao, H, Xiao, H, Zhang, J, Li, X & Sun, X 2017, 'Robust Dynamic Economic Dispatch Approach Based on Bad Scenario Set Considering Wind, EV, and Battery Switching Station', IET Generation, Transmission & Distribution, vol. 11, no. 2, pp. 354-362.View/Download from: UTS OPUS or Publisher's site
With the increasing penetration of wind power and electric vehicle (EV) into the power system, system operators face new challenges for system reliability and generation cost due to the intermittent of wind power. Furthermore, the randomly connected EVs at different time periods and locations add more uncertainty to the power system. In this study, uncertainties in wind power generation and EV charging load are modelled into the day-ahead dynamic economic dispatch (DED) problem, solution feasibility and robustness are discussed, and the bad scenario set is formulated for the day-ahead DED problem. In the obtained model, parameters can be used to adjust the positive bias or conservative bias, charging/discharging power of battery switch stations are also controlled to optimise the total cost of power system. To solve the optimisation problem, the multi-agent bacterial colony chemotaxis algorithm and a mutation strategy based on the cloud theory are developed. The simulation results show that the proposed method is effective, and battery switching station can help to reduce total cost by charging and discharging batteries.
Lu, Z, Qi, J, Zhang, J, He, L & Zhao, H 2017, 'Modelling dynamic demand response for plug-in hybrid electric vehicles based on real-time charging pricing', IET Generation, Transmission & Distribution, vol. 11, no. 1, pp. 228-235.View/Download from: UTS OPUS or Publisher's site
Based on the benefits of real-time pricing both to individual users and the society as a whole, this study introduces a real-time charging price (RTCP) mechanism supported by an intelligent charging management module into plug-in hybrid electric vehicles (PHEVs) charging environment. The optimal RTCP is executed by a distributed algorithm using a utility model to maximise the whole charging system welfare. The willingness-to-charge parameter is derived to reflect the charging preferences of PHEV users and their different responses to the RTCP. Several scenarios are established to discuss the effect of both the RTCP and willingness-to-charge on charging load. The simulation results show that reasonable charging will be realised based on the optimal RTCP mechanism.
Mokgonyana, L, Zhang, J, Li, H & Hu, Y 2017, 'Optimal location and capacity planning for distributed generation with independent power production and self-generation', Applied Energy, vol. 188, pp. 140-150.View/Download from: UTS OPUS or Publisher's site
ï¿½ 2016 Elsevier Ltd This paper proposes a planning model for power distribution companies (DISCOs) to maximize profit. The model determines optimal network location and capacity for renewable energy source, which are categorized as independent power production (IPP) and self-generation (SG). IPP refers to generators owned by third-party investors and linked to a quota obligation mechanism. SG encompasses smaller generators, supported by feed-in tariffs, that produce energy for local consumption, exporting any surplus generation to the distribution network. The obtained optimal planning model is able to evaluate network capacity to maximize profit when the DISCO is obliged to provide network access to SG and IPP. Distinct parts of the objective function, owing to the definition of SG, are revenue erosion, recovery as well as the cost of excess energy. Together with the quota mechanism for IPP, the combination of all profit components creates a connection trade-off between IPP and SG for networks with limited capacity. The effectiveness of the model is tested on 33- and 69-bus test distribution systems and compared to standard models that maximize generation capacity with predefined capacity diffusion. Simulation results demonstrate the model outperforms the standard models in satisfying the following binding constraints: minimum IPP capacity and SG net energy. It is further revealed that integrating SG and IPP with the proposed model increases profit by up to 23.7%, adding an improvement of 8% over a feasible standard model.
Liu, X, He, Y, Zheng, X, Zhang, J & Zeng, G 2017, 'A new state-of-charge estimation method for electric vehicle lithium-ion batteries based on multiple input parameter fitting model', INTERNATIONAL JOURNAL OF ENERGY RESEARCH, vol. 41, no. 9, pp. 1265-1276.View/Download from: UTS OPUS or Publisher's site
Li, X, Fang, L, Lu, Z, Zhang, J & Zhao, H 2017, 'A Line Flow Granular Computing Approach for Economic Dispatch With Line Constraints', IEEE Transactions on Power Systems, vol. 32, no. 6, pp. 4832-4842.View/Download from: UTS OPUS or Publisher's site
Line flow calculation plays a critically important role to guarantee the stable operation of power system in economic dispatch (ED) problems with line constraints. This paper presents a line flow granular computing approach for power flow calculation to assist the investigation on ED with line constraints, where the hierarchy method is adopted to divide the power network into multiple layers to reduce computational complexity. Each layer contains granules for granular computing, and the layer network is reduced by Ward equivalent retaining the PV nodes and boundary nodes of tie lines to decrease the data dimension. Then, Newton-Raphson method is applied further to calculate the power line flows within the layer. This approach is tested on IEEE 39-bus and 118-bus systems. The testing results show that the granular computing approach can solve the line flow problem in 9.2 s for the IEEE 118-bus system, while the conventional AC method needs 44.56 s. The maximum relative error of the granular computing approach in line flow tests is only 0.43%, which is quite small and acceptable. Therefore, the case studies demonstrate that the proposed granular computing approach is correct, effective, and can ensure the accuracy and efficiency of power line flow calculation.
The Qi chaotic system is transformed into a Kolmogorov-type system, thereby facilitating the analysis of energy exchange in its different forms. Regarding four forms of energy, the vector field of this chaotic system is decomposed into four forms of torque: inertial, internal, dissipative, and external. The rate of change of the Casimir function is equal to the exchange power between the dissipative energy and the supplied energy. The exchange power governs the orbital behavior and the cycling of energy. With the rate of change of Casimir function, a general bound and least upper bound of the Qi chaotic attractor are proposed. A detailed analysis with illustrations is conducted to uncover insights, in particular, cycling among the different types of energy for this chaotic attractor and key factors producing the different types of dynamic modes.
Hu, Y, Zhang, J, Li, P, Yu, D & Jiang, L 2017, 'Non-uniform Aged Modules Reconfiguration for Large Scale PV Array', IEEE Transactions on Device and Materials Reliability, vol. 17, no. 3, pp. 560-569.View/Download from: UTS OPUS or Publisher's site
In the past decades, a large number of photovoltaic (PV) plants have been built. Due to the minor physical differences between PV cells and the influence of environmental factors such as rains, temperature, and humidity, the aging of a PV array is often distributed unevenly within each PV module. This non-uniform aging causes further decreased output power, which is often easily observed for large size PV arrays. Although the global maximum power point tracking (GMPPT) strategy can improve the output power, the GMPPT cannot exploit the maximal power generation potential from non-uniform aging PV arrays. In order to exploit further the power generation potential and extend the service time of non-uniform aging PV arrays, a novel PV array reconfiguration method is developed in this paper. The concept of cell unit is applied to investigate the aging phenomenon of PV modules, and each PV module is assumed to be composed of three submodules, while these three submodules within any single PV module might have different aging conditions and, thus, different power-output capacities. The challenge is how to rearrange the PV array under the cases where: 1) each PV module has non-uniformly aged cell units; 2) there are a large number of PV modules; and 3) the voltage working range is restricted. To solve these problems, a nonlinear integer programming problem is formulated to maximize the power output under the constraints of non-uniformly aging and voltage restrictions. A small size 7 x 10 PV array is simulated to illustrate the proposed method. Furthermore, medium size 20 x 10 and large size 125 x 20 PV arrays are employed to verify the feasibility of the proposed method. A 1.5 kW 2 x 4 real PV array under non-uniform aging conditions is presented and experimentally tested to confirm the proposed rearrangement method.
Setlhaolo, D, Sichilalu, S & Zhang, J 2017, 'Residential load management in an energy hub with heat pump water heater', Applied Energy, vol. 208, pp. 551-560.View/Download from: UTS OPUS or Publisher's site
© 2017 Elsevier Ltd Today, as a consequence of the growing installation of efficient technologies, such as combined heat and power (CHP) as a co-generation, the integration of electricity through grid supply, Photovoltaic (PV) and energy storage systems as an integrated network is attracting a lot of attention in smart grid applications. To model the interaction among electricity and natural gas, the energy hub framework is adopted to determine a modelling procedure for such multi-carrier energy systems. This paper presents a residential energy hub model for a smart home as a modified framework of conventional energy hubs in a smart grid with consideration of heat pump water heater, coordination of sources and carbon emissions. Therefore, this study is twofold; the first part optimizes the operation of the combined CHP, Photovoltaic and storage system under dynamic pricing. Since residential load management plays a key role in realizing household demand response programs in a smart grid, performing optimal load management in the proposed residential energy hub model is also studied in this paper. To achieve this, the optimization problem is extended by considering modelling of a heat pump water heater. It is also found out that CO 2 signal could give customers an environmental motivation to shift or reduce loads during peak hours, as it would enable co-optimization of electricity consumption costs and carbon emissions reductions.
Chen, G, Chen, L, Deng, Y, He, X, Wang, Y & Zhang, J 2017, 'Single coupled-inductor dual output soft-switching DC-DC converters with improved cross-regulation and reduced components', IET Power Electronics, vol. 10, no. 13, pp. 1665-1678.View/Download from: UTS OPUS or Publisher's site
© The Institution of Engineering and Technology. Single inductor dual-output (SIDO) DC-DC converters are attractive in diverse applications such as renewable energy systems and electric vehicles, due to its favourable advantages of reduced magnetic core and high-power density. However, in conventional SIDO converters, severe cross-regulation problem is caused by the multiplex of inductor current, resulting in deteriorated dynamic performance. To alleviate the cross-regulation problem, a new family of dual-output DC-DC converters is proposed in this paper, which employs a coupled inductor to substitute the inductor in SIDO converters. The proposed converters can achieve improved dynamic performance while keeping the advantage of reduced magnetic core. Moreover, the number of semiconductor devices is also reduced in comparison with conventional SIDO converters, and soft-switching operation of switches is also achieved. Therefore, lower cost and higher power density are obtained. Topology derivation of proposed converters from conventional SIDO converters is firstly demonstrated in detail. After that, the operation principle, steady-state characteristics and small-signal model are provided. Finally, design example and experiment results are given to validate the merits of the proposed topology.
Lu, Z, He, L, Zhang, D, Zhang, J, Zhao, B & Zhao, H 2017, 'A security level classification method for power systems under N-1 contingency', Energies, vol. 10, no. 12, pp. 1-17.View/Download from: UTS OPUS or Publisher's site
Security assessment is crucial for the reliable and secure operation of power systems. This paper proposes a security level classification (SLC) method to analyze the security level of power systems both qualitatively and quantitatively. In this SLC method, security levels are graded according to a comprehensive safety index (CSI), which is defined by integrating the system margin index (SMI) and load entropy. The SMI depends on the operating load and the total supply capacity (TSC) under N-1 contingency, and the load entropy reflects the heterogeneity of load distribution calculated from entropy theory. In order to calculate the TSC under N-1 contingency considering both of the computational accuracy and speed, the TSC is converted into an extended conic quadratic programming (ECQP) model. In addition, the load boundary vector (LBV) model is established to obtain the capacity limit of each load bus, and thus detect potential risks of power systems. Finally, two modified practical power systems and the IEEE 118-bus test system are studied to validate the feasibility of the proposed SLC method.
Liu, X, Sun, Y, He, Y, Zheng, X, Zeng, G & Zhang, J 2017, 'Battery equalization by fly-back transformers with inductance, capacitance and diode absorbing circuits', Energies, vol. 10, no. 10.View/Download from: UTS OPUS or Publisher's site
Battery equalization can increase batteries' life cycle, utilization, and reliability. Compared with battery equalization topologies based on resistance or energy storage components, the topologies based on transformers have the advantages of high balancing current and efficiency. However, the existence of switching losses will reduce the reliability and service life span of the equalization circuit. Aiming at resolving this problem, a new battery equalization topology by fly-back transformer with an absorbing circuit is proposed in this paper. Compared with other transformer-based topologies, it can decrease switching losses because the voltage/current spike is solved by the absorbing circuit which is composed of inductance, capacitance and diode (LCD), and it can also maintain a high balancing current of about 1.8 A and high efficiency of about 89%, while the balancing current and efficiency of other topologies were usually 1.725 A/1.5 A and 80%/80.4%. The working principle of the balancing topology and the process of soft switching are analyzed and calculated in the frequency domain. Due to the addition of the LCD absorbing circuit, soft switching can be realized to reduce the switching losses while the high equalization speed and efficiency are still maintained. The corresponding control strategy of the balancing topology is also proposed and the timely balancing is achieved. The theoretical analysis is verified by simulation and experimental results.
Liu, X, Yang, Y, He, Y, Zhang, J, Zheng, X, Ma, M & Zeng, G 2017, 'A new dynamic SOH estimation of lead-acid battery for substation application', International Journal of Energy Research, vol. 41, no. 4, pp. 579-592.View/Download from: UTS OPUS or Publisher's site
Copyright © 2016 John Wiley & Sons, Ltd. State of Health (SOH) is one of the most important parameters of lead-acid batteries. Most of the existing SOH estimation methods only take the influence of charge cycles into consideration, and the estimation accuracy is limited. Batteries in the substations have two typical states: one is the check-discharge state, in which the batteries are discharged for 8 h at 0.1 C (Capacity) to determine whether the battery pack has certain reliability. The other is the floating charge state, in which the batteries are connected to the charger to maintain full power. This paper proposes a novel SOH estimation method based on the two states. In the check-discharge state, the relationship between the voltage and the age of battery is analysed. The health index, which is introduced in this model, is affected by the age of battery. In the floating state, the relationship between the internal resistance and the age of battery is discussed. Another SOH model is established based on the change of the internal resistance. By combining the two models, the estimation method can achieve real-time estimation and high accuracy for substation application. An accelerated life test is applied to verify the theoretical analysis. The experimental results demonstrate that the SOH estimation error is less than 3% which is very satisfactory for practical applications. Copyright © 2016 John Wiley & Sons, Ltd.
Hu, Y, Zhang, J, Wu, J, Cao, W, Tian, GY & Kirtley, JL 2017, 'Efficiency Improvement of Nonuniformly Aged PV Arrays', IEEE TRANSACTIONS ON POWER ELECTRONICS, vol. 32, no. 2, pp. 1124-1137.View/Download from: Publisher's site
Zhao, H, Lu, Z, Zhang, J, Li, X, Guo, X & Sun, X 2016, 'Method to decide a multi-fault rush repair robust strategy in power distribution networks', ENGINEERING APPLICATIONS OF ARTIFICIAL INTELLIGENCE, vol. 56, pp. 91-101.View/Download from: UTS OPUS or Publisher's site
Mokgonyana, L, Zhang, J, Zhang, L & Xia, X 2016, 'Coordinated two-stage volt/var management in distribution networks', ELECTRIC POWER SYSTEMS RESEARCH, vol. 141, pp. 157-164.View/Download from: Publisher's site
© 2016 The Authors. It is noted that human behaviour changes can have a significant impact on energy consumption, however, qualitative study on such an impact is still very limited, and it is necessary to develop the corresponding mathematical models to describe how much energy savings can be achieved through human engagement. In this paper a mathematical model of human behavioural dynamic interactions on a social network is derived to calculate energy savings. This model consists of a weighted directed network with time evolving information on each node. Energy savings from the whole network is expressed as mathematical expectation from probability theory. This expected energy savings model includes both direct and indirect energy savings of individuals in the network. The savings model is obtained by network weights and modified by the decay of information. Expected energy savings are calculated for cases where individuals in the social network are treated as a single information source or multiple sources. This model is tested on a social network consisting of 40 people. The results show that the strength of relations between individuals is more important to information diffusion than the number of connections individuals have. The expected energy savings of optimally chosen node can be 25.32% more than randomly chosen nodes at the end of the second month for the case of single information source in the network, and 16.96% more than random nodes for the case of multiple information sources. This illustrates that the model presented in this paper can be used to determine which individuals will have the most influence on the social network, which in turn provides a useful guide to identify targeted customers in energy efficiency technology rollout programmes.
Hu, Y, Zeng, R, Cao, W, Zhang, J & Finney, SJ 2016, 'Design of a Modular, High Step-Up Ratio DC-DC Converter for HVDC Applications Integrating Offshore Wind Power', IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS, vol. 63, no. 4, pp. 2190-2202.View/Download from: Publisher's site
Hu, Y, Gan, C, Cao, W, Zhang, J, Li, W & Finney, SJ 2016, 'Flexible Fault-Tolerant Topology for Switched Reluctance Motor Drives', IEEE TRANSACTIONS ON POWER ELECTRONICS, vol. 31, no. 6, pp. 4654-4668.View/Download from: Publisher's site
Chen, G, Deng, Y, He, X, Wang, Y & Zhang, J 2016, 'Zero-voltage-switching buck converter with low-voltage stress using coupled inductor', IET POWER ELECTRONICS, vol. 9, no. 4, pp. 719-727.View/Download from: Publisher's site
Setlhaolo, D, Xia, X & Zhang, J 2016, 'Optimal scheduling of household appliances for demand response (vol 116, pg 24, 2014)', ELECTRIC POWER SYSTEMS RESEARCH, vol. 130, pp. 220-221.View/Download from: Publisher's site
Zhang, L, Xia, X & Zhang, J 2015, 'Medium Density Control for Coal Washing Dense Medium Cyclone Circuits', IEEE Transactions on Control Systems Technology, vol. 23, no. 3, pp. 1117-1122.View/Download from: Publisher's site
© 1993-2012 IEEE. The dense medium cyclone (DMC) process used in coal beneficiation plants is studied from a control system perspective. Employing the dynamic model of the DMC process derived from mass flow balance, a model-based control strategy is proposed. The controller adjusts the density of medium used to enhance separation in the DMC process according to measurements on percentages of different components in raw coal. The first objective of the control is to maintain the carbon content in the clean coal to a set level. The second purpose is to minimize energy consumption of the DMC process in view of the fast increasing electricity price. The controller solves an optimization problem formulated to determine the density of medium whenever new measurements are available. Both coal quality and DMC operational constraints are accounted for. Simulations, based on measured plant data, are carried out to verify the feasibility and effectiveness of the control strategy designed. The results show that the designed controller is able to fulfill its purpose satisfactorily when the characteristics of the raw coal varies and when measurement uncertainties are in presence.
Ekpenyong, UE, Zhang, J & Xia, X 2015, 'How information propagation in social networks can improve energy savings based on time of use tariff', SUSTAINABLE CITIES AND SOCIETY, vol. 19, pp. 26-33.View/Download from: Publisher's site
Hu, Y, Zhang, J, Cao, W, Wu, J, Tian, GY, Finney, SJ & Kirtley, JL 2015, 'Online Two-Section PV Array Fault Diagnosis With Optimized Voltage Sensor Locations', IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS, vol. 62, no. 11, pp. 7237-7246.View/Download from: Publisher's site
Ye, X, Xia, X & Zhang, J 2014, 'Optimal sampling plan for clean development mechanism lighting projects with lamp population decay', APPLIED ENERGY, vol. 136, pp. 1184-1192.View/Download from: Publisher's site
Qu, S, Xia, X & Zhang, J 2014, 'Dynamical Behaviors of an Euler Discretized Sliding Mode Control Systems', IEEE TRANSACTIONS ON AUTOMATIC CONTROL, vol. 59, no. 9, pp. 2525-2529.View/Download from: Publisher's site
Mathaba, T, Xia, X & Zhang, J 2014, 'Analysing the economic benefit of electricity price forecast in industrial load scheduling', ELECTRIC POWER SYSTEMS RESEARCH, vol. 116, pp. 158-165.View/Download from: Publisher's site
Wang, B, Xia, X & Zhang, J 2014, 'A multi-objective optimization model for the life-cycle cost analysis and retrofitting planning of buildings', ENERGY AND BUILDINGS, vol. 77, pp. 227-235.View/Download from: Publisher's site
Qu, S, Xia, X & Zhang, J 2014, 'Dynamics of Discrete-Time Sliding-Mode-Control Uncertain Systems With a Disturbance Compensator', IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS, vol. 61, no. 7, pp. 3502-3510.View/Download from: Publisher's site
Zhang, L, Xia, X & Zhang, J 2014, 'Improving energy efficiency of cyclone circuits in coal beneficiation plants by pump-storage systems', APPLIED ENERGY, vol. 119, pp. 306-313.View/Download from: Publisher's site
Ye, X, Xia, X & Zhang, J 2013, 'Optimal sampling plan for clean development mechanism energy efficiency lighting projects', APPLIED ENERGY, vol. 112, pp. 1006-1015.View/Download from: Publisher's site
Tazvinga, H, Xia, X & Zhang, J 2013, 'Minimum cost solution of photovoltaic-diesel-battery hybrid power systems for remote consumers', SOLAR ENERGY, vol. 96, pp. 292-299.View/Download from: Publisher's site
Malatji, EM, Zhang, J & Xia, X 2013, 'A multiple objective optimisation model for building energy efficiency investment decision', ENERGY AND BUILDINGS, vol. 61, pp. 81-87.View/Download from: Publisher's site
Ye, X, Xia, X, Zhang, J & Chen, Y 2012, 'Effects of trends and seasonalities on robustness of the Hurst parameter estimators', IET SIGNAL PROCESSING, vol. 6, no. 9, pp. 849-856.View/Download from: Publisher's site
Xia, X, Zhang, J & Cass, W 2012, 'Energy management of commercial buildings - A case study from a POET perspective of energy efficiency', JOURNAL OF ENERGY IN SOUTHERN AFRICA, vol. 23, no. 1, pp. 23-31.
Zhang, H, Xia, X & Zhang, J 2012, 'Optimal sizing and operation of pumping systems to achieve energy efficiency and load shifting', ELECTRIC POWER SYSTEMS RESEARCH, vol. 86, pp. 41-50.View/Download from: Publisher's site
Badenhorst, W, Zhang, J & Xia, X 2011, 'Optimal hoist scheduling of a deep level mine twin rock winder system for demand side management', ELECTRIC POWER SYSTEMS RESEARCH, vol. 81, no. 5, pp. 1088-1095.View/Download from: Publisher's site
van Staden, AJ, Zhang, J & Xia, X 2011, 'A model predictive control strategy for load shifting in a water pumping scheme with maximum demand charges', APPLIED ENERGY, vol. 88, no. 12, pp. 4785-4794.View/Download from: Publisher's site
Zhang, J & Xia, X 2011, 'A model predictive control approach to the periodic implementation of the solutions of the optimal dynamic resource allocation problem', AUTOMATICA, vol. 47, no. 2, pp. 358-362.View/Download from: Publisher's site
Xia, X, Zhang, J & Elaiw, A 2011, 'An application of model predictive control to the dynamic economic dispatch of power generation', CONTROL ENGINEERING PRACTICE, vol. 19, no. 6, pp. 638-648.View/Download from: Publisher's site
Zhang, J, Moog, CH & Xia, X 2010, 'Realization of multivariable nonlinear systems via the approaches of differential forms and differential algebra', Kybernetika, vol. 46, no. 5, pp. 799-830.
In this paper differential forms and differential algebra are applied to give a new definition of realization for multivariable nonlinear systems consistent with the linear realization theory. Criteria for the existence of realization and the definition of minimal realization are presented. The relations of minimal realization and accessibility and finally the computation of realizations are also discussed in this paper.
Middelberg, A, Zhang, J & Xia, X 2009, 'An optimal control model for load shifting - With application in the energy management of a colliery', APPLIED ENERGY, vol. 86, no. 7-8, pp. 1266-1273.View/Download from: Publisher's site
Liang, X, Zhang, J & Xia, X 2008, 'Improving the security of chaotic synchronization with a Delta-modulated cryptographic technique', IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS II-EXPRESS BRIEFS, vol. 55, no. 7, pp. 680-684.View/Download from: Publisher's site
Liang, X, Zhang, J & Xia, X 2008, 'Adaptive Synchronization for Generalized Lorenz Systems (vol 53, pg 1740, 2008)', IEEE TRANSACTIONS ON AUTOMATIC CONTROL, vol. 53, no. 9, pp. 2216-2216.View/Download from: Publisher's site
Zhang, J, Xia, X & Moog, CH 2006, 'Parameter identifiability of nonlinear systems with time-delay', IEEE TRANSACTIONS ON AUTOMATIC CONTROL, vol. 51, no. 2, pp. 371-375.View/Download from: Publisher's site
Zhang, JF & Kwong, CP 2005, 'Some applications of a polynomial inequality to global optimization', JOURNAL OF OPTIMIZATION THEORY AND APPLICATIONS, vol. 127, no. 1, pp. 193-205.View/Download from: Publisher's site
We propose an equivalent representation of an open problem in bistable stabilization. Using this new formulation we derive two simple necessary condition tests for the solution of the problem. For certain special cases we also obtain the sufficient conditions. © 2004 Elsevier B.V. All rights reserved.
Sun, Y, Yue, H, Zhang, J & Booth, C 2019, 'Minimisation of Residential Energy Costs for PV-SWH and PV-T Systems', 12th IFAC Symposium on Dynamics and Control of Process Systems, including Biosystems, Brazil.View/Download from: UTS OPUS
Razavi, S-E, Falaghi, H, Azizivahed, A, Ghavidel, S, Li, L & Zhang, J 2018, 'Improved Probabilistic Multi-Stage PMU Placement with an Increased Search Space to Enhance Power System Monitoring', Tokyo, Japan.View/Download from: UTS OPUS
Ghavidel Jirsaraie, S, Azizivahed, A, Barani, M, Aghaei, J, Li, L & Zhang, J 2017, 'Static Var Compensator Allocation Considering Transient Stability, Voltage Profile and Losses', The 20th International Conference on Electrical Machines and Systems (ICEMS), International Conference on Electrical Machines and Systems, IEEE, Sydney, NSW, Australia, pp. 1-6.View/Download from: UTS OPUS or Publisher's site
The purpose of this paper is to determine the optimal location, size and controller parameters of Static Var Compensator (SVC) to simultaneously improve static and dynamic objectives in a power system. Four goals are considered in this paper including transient stability, voltage profile, SVC investment cost and power loss reduction. Along with the SVC allocation for improving the system transient stability, an additional controller is used and adjusted to improve the SVC performance. Also, an estimated annual load profile including three load levels is utilized to accurately find the optimal location and capacity of SVC. By considering three load levels, the cost of power losses in the power system is decreased significantly. The combination of the active power loss cost and SVC investment cost is considered as a single objective to obtain an accurate and practical solution, while the improvement of transient stability and voltage profile of the system are considered as two separate objectives. The problem is therefore formulated as a multi-objective optimization problem, and Multi Objective Particle Swarm Optimization (MOPSO) algorithm is utilized to find the best solutions. The suggested technique is verified on a 10-generator 39-bus New England test system. The results of the nonlinear simulation indicate that the optimal sizing, location and controller parameters setting of SVC can improve significantly both static and dynamic performance of the system.
Ghavidel, S, Barani, M, Azizivahed, A, Ghadi, M, Li, L & Zhang, J 2017, 'Hybrid Power Plant Offering Strategy to Deal with the Stochastic Nature and Outage of Wind Generators', The 20th International Conference on Electrical Machines and Systems (ICEMS), International Conference on Electrical Machines and Systems, IEEE, Sydney, NSW, Australia, pp. 1-6.View/Download from: UTS OPUS or Publisher's site
The stochastic nature of wind power generators and their possible outage are crucial issues which make them difficult to participate in electricity markets. However, demand side as a decent balancing resource can be used to compensate the challenges of lack of supply-demand balance or state of outage for wind generators. This paper firstly models the outage of wind generators. Then an offering strategy with a three-stage stochastic programming is presented for a hybrid power plant which includes a wind power producer and a demand response provider. Three electricity markets are considered including day-ahead, adjustment and balancing market. The conditional value-at-risk is also added to the offering strategy to control the profit risk. The offering strategy is tested in a wind farm and electricity market located in Spain. The result shows that the hybrid power plant offering strategy can effectively assist with the balancing and outage problem of the wind power producer and increase the overall profit of the joint operation.
Abbasi, M, Taki, M, Rajabi, A, Li, L, Zhang, JF & Ghavidel, S 2017, 'Managing the Cumulative Distribution Function of The profit: a Producer Risk Management Case', 20th International Conference on Electrical Machines and Systems (ICEMS), International Conference on Electrical Machines and Systems, IEEE, Sydney, NSW, Australia.View/Download from: UTS OPUS or Publisher's site
This paper presents a new framework for risk consideration of participants in electricity markets. Current approaches add risk measures to stochastic problem formulation in order to control the variation of the profits (costs). However, in the proposed method, cumulative distribution function of profit is utilized and it is shaped based on the preferred risk levels of the producer (buyer). The features of this new method are compared with the current approaches based on a detailed case study performed on the problem of a producer participating in a three settlement market.
Abbasi, M, Rajabi, A, Taki, M, Li, L, Ghavidel, S & Ghadi, M 2017, 'Risk-Constrained Offering Strategies of a Price-Maker Demand Response Aggregator', 20th International Conference on Electrical Machines and Systems (ICEMS), International Conference on Electrical Machines and Systems, IEEE, Sydney, NSW, Australia.View/Download from: UTS OPUS or Publisher's site
Offering strategy of a price-maker demand response aggregator (DRA) in a two-settlement market is presented in this paper. The aggregator minimizes its cost by offering energy and price bids in the day-ahead market and energy bids in the balancing market. On the other hand, DRA optimally manages the aggregated demands of a large number of electric vehicles and properly distributes them through the time. The problem is formulated as a stochastic mixed-integer nonlinear optimization problem. The risk of the problem is managed by conditional value-at-risk measure and finally, the proposed approach is numerically evaluated through a detailed case study.
Azizivahed, A, Ghavidel Jirsaraie, S, Ghadi, M, Li, L & Zhang, J 2017, 'New Energy Management Approach in Distribution Systems Considering Energy Storages', 20th International Conference on Electrical Machines and Systems (ICEMS), International Conference on Electrical Machines and Systems, IEEE, Sydney, NSW, Australia.View/Download from: UTS OPUS or Publisher's site
This paper presents a new method for energy management in distribution networks in the presence of energy storage, solar photovoltaic (PV) systems and diesel generators. Achieving optimal charge and discharge pattern for batteries and optimal diesel generator output with minimal operation cost are the main goal of this paper. The innovation of this paper is to consider the network effect on the underlying method with operational limitations and power-flow constraints such as power loss, voltage and current limitation. The proposed problem is solved for 24-hour time horizon, and the modified imperialist competitive algorithm (ICA) is also developed using mutation strategy to optimally solve the problem. Finally, to show the good performance and supremacy of the proposed method, a 33-bus IEEE standard test system is applied.
Azizivahed, A, Ghavidel Jirsaraie, S, Ghadi, M, Li, L & Zhang, J 2017, 'Multi-Area Economic Emission Dispatch Considering Load Uncertainty', 20th International Conference on Electrical Machines and Systems (ICEMS), International Conference on Electrical Machines and Systems, IEEE, Sydney, NSW, Australia.View/Download from: UTS OPUS or Publisher's site
Multi-area economic emission dispatch problem provides an optimal schedule for active power of generators and interchange active power between different areas by considering the operational limitations such as balance between generation and consumption, tie-line capacity limitation, generators output constraint, and transmission losses. In this paper, a hybrid method based on shuffled frog leaping algorithm (SFLA) and particle swarm optimization (PSO) is presented to achieve better solution. Furthermore, the stochastic nature of energy consumption is modeled as uncertainty source using scenario reduction technique to achieve the results which are closer to the real condition. The performance of the proposed approach is elaborated in two test systems with different scales including 10-generator with three-area and 40-generator with four-area. The obtained results are compared with those available in the literature to show the effectiveness of the proposed approach.
Azizivahed, A, Ghavidel, S, Ghadi, MJ, Li, L & Zhang, J 2017, 'A Novel Reliability Oriented Bi-Objective Unit Commitment Problem', Proceedings of the 2017 Australasian Universities Power Engineering Conference (AUPEC), Australasian Universities Power Engineering Conference, IEEE, Melbourne, Australia, pp. 1-6.View/Download from: UTS OPUS or Publisher's site
This paper presents a new solution to unit commitment for single-objective and multi-objective frameworks. In the first step, the total expected energy not supplied (TEENS) is proposed as a separate reliability objective function and at the next step, the multi-objective Pareto front strategy is implemented to simultaneously optimize the cost and reliability objective functions. Additionally, an integer based codification of initial solutions is added to reduce the dimension of ON/OFF status variables and also to eliminate the negative influence of penalty factor. The modified invasive weed optimization (MIWO) algorithm is also developed to optimally solve the proposed problem. The obtained solutions are compared with results in the literature which confirms the applicability and superiority of the proposed algorithm for a 10-unit system and 24-hour scheduling horizon.
Ghavidel, S, Ghadi, MJ, Azizivahed, A, Barani, M, Aghaei, J, Li, L & Zhang, J 2017, 'Hybrid Power Plant Bidding Strategy Including a Commercial Compressed Air Energy Storage Aggregator and a Wind Power Producer', 2017 Australasian Universities Power Engineering Conference (AUPEC), Australasian Universities Power Engineering Conference, IEEE, Melbourne, AUSTRALIA, pp. 1-6.View/Download from: UTS OPUS or Publisher's site
In this paper, a commercial compressed air energy storage (CAES) aggregator equipped with a simple cycle mode operation having the ability to work like a gas turbine is coordinated with a wind power aggregator (WPA) as a hybrid power plant to participate in electricity markets. In the proposed approach, the WPA uses the CAES to tackle its stochastic input and uncertainties related to different electricity market prices, and CAES can also use WPA to manage its charging/discharging and simple cycle modes more economically. A three-stage stochastic decision-making method is used to model the mentioned optimization problem which considers three electricity markets including day-ahead, intraday and balancing markets. The problem is formulated as a mixed integer linear programming which can be solved with available commercial solvers. Also, conditional value-at-risk is added to the problem to control the financial risk of the problem and offer different operation strategies for different financials risk levels. The proposed method can provide both bidding quantity and bidding curves to be submitted to the electricity markets which is tested on a realistic case study based on a wind farm and electricity market located in Spain. The results confirm that the proposed method can provide extra profit in joint operation, have more flexibility and reduce the financial risks
Rajabi, A, Li, L, Zhang, J, Zhu, J, Ghavidel, S & Ghadi, M 2017, 'A Review on Clustering of Residential Electricity Customers and Its Applications', Proceedings of the The 20th International Conference on Electrical Machines and Systems (ICEMS), International Conference on Electrical Machines and Systems, IEEE, Sydney, Australia, pp. 1-6.View/Download from: UTS OPUS or Publisher's site
Clustering is a well-recognized data mining
technique which enables the determination of underlying
patterns in datasets. In electric power systems, it has been
traditionally utilized for different purposes like defining
customer load profiles, tariff designs and improving load
forecasting. Some surveys summarized different clustering
techniques which were traditionally used for customer
segmentation and load profiling. The recent changes in
power system structure and introduction of new technologies
necessitate the new investigation of applications and benefits
of clustering methods for power systems. In this regard, this
paper aims at reviewing the new research for clustering
techniques for residential customers.
Rajabi, A, Li, L, Zhang, J & Zhu, J 2017, 'Aggregation of Small Loads for Demand Response Programs - Implementation and Challenges: a Review', Proceedings of the 2017 IEEE International Conference on Environment and Electrical Engineering and 2017 IEEE Industrial and Commercial Power Systems Europe (EEEIC / I&CPS Europe), Annual conference of the International Conference on Environmental and Electrical Engineering, IEEE, Milan, Italy, pp. 1-6.View/Download from: UTS OPUS or Publisher's site
The concepts of demand response (DR) and demand side management have been in practice by power utilities for many decades. Due to fundamental changes in the electricity structure in recent years, the provision of DR from small loads like residential buildings or electric vehicles has become possible. However, there are still many challenges to the real implementation of DR programs for such customers. Based on a detailed survey of the literature, this paper tries to illustrate the role of aggregators in the implementation and expansion of DR in future smart grids. Then different technical and managerial challenges of DR aggregation for residential customers will be discussed thoroughly.
The expected savings from energy efficiency projects are divided into two the technical or direct savings and the non-technical or indirect savings. The human and social contributions also known as the non-technical savings are rarely acknowledged when quantifying the total expected energy savings although humans are the ones that use the energy. This paper presents an extension for the mathematical model of the social impacts of energy efficiency projects and calculates the total expected energy saving. The indirect/non-technical savings are dependent on the on the type of relationship an individual has with his/her neighbour. In this paper, the functional and conditional probabilities of all the people in a network are determined based on the influence each has on his/her neighbour. An example to illustrate the usefulness of the mathematical model is given for a community of thirty-six households. In the community, a limited number of rebates are given to some members based on how much indirect energy savings they have, these indirect savings help to improve the total expected savings. The results show that the expected energy savings are determined not only on the number of neighbours an individual has but also on the influence he/she has on those neighbours. © 2013 IEEE.
Model Predictive Control (MPC) was applied in Economic Dispatching (ED) problem, but its computation burden was large due to high complexity and dimension of problems. In this paper, a decomposed MPC approach is proposed to reduce the computational time without decreasing the performance of convergence and robustness. The decomposed MPC uses the "divide and conquer" concept, and divides the original problem into two less difficult sub-problems. The proposed MPC has been tested on a 6-unit system, and the results have been shown that decomposition can deliver promising solutions with less computation time. © 2013 IEEE.
Carstens, H, Xia, X, Zhang, J & Ye, X 2013, 'Characterising Compact Fluorescent Lamp Population Decay', AFRICON, 2013, AFRICON Conference, IEEE, IEEE Reg 8, Pointe aux Piments, MAURITIUS, pp. 127-131.
In this paper, a metering cost minimisation model is proposed to find out the optimal solutions to the meter commitment problem for the CDM energy efficiency lighting projects. Under the typical CDM sampling accuracy requirement, known as 90/10 criterion, the optimal confidence and precision levels for each lighting group have been characterised. The dynamics of the lighting population decay are also incorporated in the proposed model. The optimal solutions to the model minimise the metering cost whilst satisfying the 90/10 criterion, and this is verified by a case study. The metering cost minimisation model proposed for lighting systems is applicable to other CDM projects as well. © 2013 IEEE.
Mathaba, T, Xia, X & Zhang, J 2012, 'Optimal Scheduling of Conveyor Belt Systems under Critical Peak Pricing', 2012 CONFERENCE ON POWER & ENERGY - IPEC, 10th International Power and Energy Conference (IPEC), IEEE, Ho Chi Minh City, VIETNAM, pp. 315-320.
Mathaba, T, Xia, X & Zhang, J 2012, 'Short-term Wind Power Prediction using Least-Square Support Vector Machines', 2012 IEEE POWER ENGINEERING SOCIETY CONFERENCE AND EXPOSITION IN AFRICA (POWERAFRICA), IEEE-Power-Engineering-Society Conference and Exposition in Africa (PowerAfrica), IEEE, Johannesburg, SOUTH AFRICA.
Ye, X, Xia, X, Zhang, J & Chen, Y 2011, 'Characterizing Long Memories in Electric Water Heater Power Consumption Time Series', IEEE AFRICON 2011, IEEE Africon Conference, IEEE, Livingstone, ZAMBIA.
Xia, X & Zhang, J 2011, 'Mathematical description of the performance measurement and verification', IEEE AFRICON 2011, IEEE Africon Conference, IEEE, Livingstone, ZAMBIA.
Bijker, AJ, Xia, X & Zhang, J 2009, 'Active Power Residential Non-intrusive Appliance Load Monitoring System', 2009 AFRICON, VOLS 1 AND 2, 9th IEEE AFRICON Conference, IEEE, Nairobi, KENYA, pp. 245-250.
Xia, X, Zhang, J & Elaiw, A 2009, 'A Model Predictive Control Approach to Dynamic Economic Dispatch Problem', 2009 IEEE BUCHAREST POWERTECH, VOLS 1-5, Bucharest PowerTech Conference, IEEE, Bucharest, ROMANIA, pp. 2731-2737.
Liang, X, Zhang, J & Xia, X 2008, 'On the application of parameter identifiability to the security of chaotic synchronization', 2008 7TH WORLD CONGRESS ON INTELLIGENT CONTROL AND AUTOMATION, VOLS 1-23, 7th World Congress on Intelligent Control and Automation, IEEE, Chongqing, PEOPLES R CHINA, pp. 508-512.View/Download from: Publisher's site
Zhang, J 2008, 'Simultaneous upper triangularization and the stability of linear discrete multidimensional systems', 2008 7TH WORLD CONGRESS ON INTELLIGENT CONTROL AND AUTOMATION, VOLS 1-23, 7th World Congress on Intelligent Control and Automation, IEEE, Chongqing, PEOPLES R CHINA, pp. 513-518.View/Download from: Publisher's site
Liang, X, Zhang, J & Xia, X 2007, 'Adaptive synchronization for a class of chaotic system', 2007 AFRICON, VOLS 1-3, 8th IEEE Africon Conference, IEEE, Windhoek, NAMIBIA, pp. 454-459.
Zhang, J & Xia, X 2007, 'Best switching time of hot water cylinder-switched optimal control approach', 2007 AFRICON, VOLS 1-3, 8th IEEE Africon Conference, IEEE, Windhoek, NAMIBIA, pp. 436-441.
Xia, X & Zhang, J 2007, 'Steady states of nonlinear systems', 2007 IEEE INTERNATIONAL CONFERENCE ON CONTROL AND AUTOMATION, VOLS 1-7, IEEE International Conference on Control and Automation, IEEE, Guangzhou, PEOPLES R CHINA, pp. 2113-+.