Liuchen Chang

University of New Brunswick, Fredericton, New Brunswick, Canada

Are you Liuchen Chang?

Claim your profile

Publications (124)47 Total impact

  • Mao Meiqin, Niu Chengyu, Liuchen Chang
    [Show abstract] [Hide abstract]
    ABSTRACT: In order to design and test the control algorithms of the actual direct-drive wind generation system (DDWGS) with a permanent magnet synchronous generator (PMSG), it is necessary to reproduce the dynamic performances of wind turbine and PMSG in the lab. After the analysis of the aerodynamic, mechanical model of wind turbine and the electrical model of PMSG, a novel simulator based on three-phase voltage source inverter and DSP for a DDWGS with PMSG is proposed in this paper. Based on Park's transformation, double closed-loop PI control algorithm and space vector PWM, the proposed simulator which eliminates electro-mechanical parts can simulate the external mechanical and electrical characteristics of PMSG. The simulation and experiment results show that the proposed simulator can accurately simulate the external mechanical and electrical characteristics of the actual DDWGS with PMSG under static and dynamic conditions.
    ECCE Asia Downunder (ECCE Asia), 2013 IEEE; 01/2013
  • Meiqin Mao, Wenjian Gong, Liuchen Chang
    [Show abstract] [Hide abstract]
    ABSTRACT: A combined prediction method based on ensemble empirical mode decomposition (EEMD) and support vector machine (SVM) is proposed to tackle with the problem of the short-term forecast of photovoltaic system (PVs) hourly output a day ahead. Weather types are divided into abnormal day (weather changed suddenly) and normal day. By the proposed method, firstly, the history data for hourly output of PVs is decomposed into a series of components by using EEMD method. Considering different factors for different type of weather, different models are built and different kernel functions and parameters are chosen to deal with each component of the decomposed data by using SVM. Simulation results show that the proposed classification modeling ideas and EEMD-SVM combination forecasting method enable that the mean absolute percentage error results for the abnormal days is decreased by 5%, and for normal day is decreased by 3% comparing with the traditional SVM method and Back Propagation (BP) neural network method respectively.
    Energy Conversion Congress and Exposition (ECCE), 2013 IEEE; 01/2013
  • [Show abstract] [Hide abstract]
    ABSTRACT: In this paper, a power-frequency (P-ω) controller is presented for voltage source converters (VSC). The approach is intended for multiple parallel VSCs forming a microgrid operating in both grid-connected and islanded modes. The proposed controller allows a VSC to mimic the operation of a synchronous generator (SG) by implementing the swing equation of SG with a primary frequency controller. In addition, a generalized model of the active power generation dynamics is developed in order to analyze the stability and to design the main control parameters. In contrast with the conventional droop control method, the proposed controller improves the close-loop system dynamic response without changing the frequency accuracy. The obtained results show the good performance of the proposed controller.
    ECCE Asia Downunder (ECCE Asia), 2013 IEEE; 01/2013
  • [Show abstract] [Hide abstract]
    ABSTRACT: An economic evaluation method and optimal allocation model of the industrial PV microgrids are proposed in this paper. The economic indexes include levelized energy cost, emission reduction benefits and payback period. The optimal model considering various relevant issues such as local insolation level and detailed investment costs is established and applied to improve the configuration of the PV microgrids for four different operation strategies. The optimization problem is solved by Particle Swarm Optimization to obtain the minimum annual energy cost of the system and bring more economic and emission reduction benefits for industrial users. The simulation results based on three months running data of a 500kW industrial PV microgrid in Dongguan City, China, verify that the optimal allocations by the proposed method can meet the technical indicators as well as the economic optimum, thus effectively optimizing industrial PV microgrid in both economic and environmental way. In addition, the added batteries can not only be used to maximize the utilization of renewable energy, but also enhance the system's ability of peak load shifting. Besides, the sensitivity of the impact of different parameters on the system is also performed. The economic evaluation and optimal allocation of the industrial PV microgrids in this paper provide a reference for the application of similar projects.
    Energy Conversion Congress and Exposition (ECCE), 2013 IEEE; 01/2013
  • Source
    T. Kamel, Y. Biletskiy, C.P. Diduh, Liuchen Chang
    [Show abstract] [Hide abstract]
    ABSTRACT: This paper provides new methods to detect and investigate the failure in the DC filter of the power rectifier. The proposed diagnoses techniques are interested in two types of capacitor faults; capacitor aging and capacitor open circuit O.C. faults. The required inputs for the methods are the ripple of the DC voltage of the capacitors as well as the loading and the supply conditions.
    Electrical & Computer Engineering (CCECE), 2012 25th IEEE Canadian Conference on; 01/2012
  • Source
    T. Kamel, Y. Biletskiy, C.P. Diduh, Liuchen Chang
    [Show abstract] [Hide abstract]
    ABSTRACT: This paper presents a fault detection, classification, and diagnoses for all the successive stages of the power electronic converter, including; the three phase rectifier, the dc-dc converter, and finally the single phase inverter. The paper provides a number of proposed algorithms for the open circuit fault diagnoses of these stages. The inputs of these algorithms are the voltage and current measurements of these stages after they undergo certain signal processing so that the inputs of the proposed algorithms could efficiently reflect the fault occurrence and behaviour.
    Electrical & Computer Engineering (CCECE), 2012 25th IEEE Canadian Conference on; 01/2012
  • Source
    T. Kamel, C. Diduch, Y. Bilestkiy, Liuchen Chang
    [Show abstract] [Hide abstract]
    ABSTRACT: DC filters are responsible for more than half of the failures in electric power converters. One approach to improving the reliability, performance and maintainability is to include failure diagnosis logic within the power converter. DC bus capacitor failures may be classified as gradual faults caused by capacitor aging and sudden faults which may take the form of breakdown faults resulting from a blown capacitor fuse, and open circuit O-C faults. This paper presents new methods to detect and isolate failures in the DC filters of power converters caused by capacitor aging and O-C faults.
    Energy Conversion Congress and Exposition (ECCE), 2012 IEEE; 01/2012
  • [Show abstract] [Hide abstract]
    ABSTRACT: This paper proposes a detection method for open-circuit faults in a 3-phase uncontrolled rectifier that forms the input stage of a single-phase current controlled power converter. The rectifier is driven by a 3-phase wind generator with variable amplitude and frequency. The algorithm is based on fault signatures embedded within the output voltage ripple of the rectifier. It is demonstrated that seven different classes of open circuit faults can be detected and isolated.
    Power Electronics for Distributed Generation Systems (PEDG), 2012 3rd IEEE International Symposium on; 01/2012
  • [Show abstract] [Hide abstract]
    ABSTRACT: Power converters are widely used to control the power energy generated by distributed generators in power grids. The operation of power converters involves monitoring and adjustment of voltage and current by power devices, which are switching rapidly. The rapid switching causes spikes that can result in the false detection of voltage faults. This present paper describes a method to detect and remove spikes from power converter sensors that allows power converter to be not affected. The methodology behind the present work is the use of discrete wavelet transform enabling spike detection and removal.
    Electrical & Computer Engineering (CCECE), 2012 25th IEEE Canadian Conference on; 01/2012
  • [Show abstract] [Hide abstract]
    ABSTRACT: Economic performances of a microgrid with multi-energy are effected by many factors such as the configuration of microgrid systems for the specific installation sites and cluster of loads, operation modes and dispatching schedules of the microgrid, the electricity market, energy policy and alike. And the configuration of the microgrid is the premise of all factors. This paper presents an optimization model to quantitatively evaluate the economic impacts of different installation sites on microgrids with multi-energy. In this model, optimal configuration schemes for microgrids installed at typical sites are designed by particle swarm optimization method. The economic performances of optimal configuration schemes are evaluated by the operation simulation with the proposed indexes. Those typical installation sites mentioned above belong to different regions which are divided into the five-level classifications in terms of the richness of wind and solar resource and the distributions of loads in China. The calculation results may be used for the decision-making references by the decision-makers.
    Power Electronics for Distributed Generation Systems (PEDG), 2012 3rd IEEE International Symposium on; 01/2012
  • [Show abstract] [Hide abstract]
    ABSTRACT: A novel control method based on the proportional resonant differential (PRD) control is proposed for the grid-connected current source inverter (CSI) used in the direct drive permanent magnet synchronous wind generation system. By the optimal design of the parameters of the PRD controller in two-phase stationary frame, the CSI system can realize zero steady-state error control and effectively damp the resonance caused by its output LC filter just by feeding back the grid-connected current. This not only greatly simplifies the controller design but also enhances the stability of the system. Simulation results show grid-connected CSI with this method has fast dynamic response and good steady-state performances.
    Power Electronics for Distributed Generation Systems (PEDG), 2012 3rd IEEE International Symposium on; 01/2012
  • Riming Shao, M. Kaye, Liuchen Chang
    [Show abstract] [Hide abstract]
    ABSTRACT: Abstract-The power converter is a critical component of a distributed generation (DG) system, particularly for a renewable energy based distributed generator. With the rapid development and growing applications of DG systems, power converters have evolved from a traditional "power conversion device" to a "system integrator". This paper outlines the basic and advanced building blocks of power converters for distributed generation systems, with an emphasis on the new algorithms developed especially for grid-connected single-phase power converters in small wind turbines and photovoltaic systems. A grid-connected power converter should feed power of a high quality into a grid with a low total harmonic distortion (THD), and fast dynamic response to the variations of a renewable energy resource. The newly developed space vector based pulse width-modulation (PWM) with predictive current control provides a direct cycle-by-cycle regulation of the current waveform feeding into the grid. Effective anti-islanding is an essential function of a power converter, in compliance with the grid interconnection requirements. As active islanding detection methods exert disturbances to the grid and passive islanding detection methods generally have large non-detection zones, new and hybrid islanding detection methods have been developed. A power spectral density method has been developed to continuously monitor and identify the possible features of an islanding formation. Maximum power extraction from renewable energy resources is vitally important for distributed generators. Many algorithms have been developed for maximum power point tracking (MPPT) of photovoltaic and wind energy systems. A new MPPT method has been developed by integrating the fast extremum-finding method of Golden Section Search (GSS) into a multi-stage MPPT algorithm. The proposed MPPT algorithm provides fast response (in the order of 40 msec) and high tracking accuracy (99.9%) as compared to the existing algorithms.
    Power Electronics and ECCE Asia (ICPE & ECCE), 2011 IEEE 8th International Conference on; 07/2011
  • Source
    Hossein Madadi Kojabadi, Liuchen Chang
    04/2011; , ISBN: 978-953-307-221-0
  • Source
    04/2011; , ISBN: 978-953-307-221-0
  • Mao Meiqin, Dong Wei, Liuchen Chang
    [Show abstract] [Hide abstract]
    ABSTRACT: This paper presents a general multi-agent based model for the hierarchical and distributed energy control of a Microgrid. In this model, the agents under three different levels are classified and defined in detail. And based on the model, a novel simulation platform for the energy management system of the Microgrid (EMS-MG) is designed in terms of Client-Server and implemented under C++ Builder environment. Taking the generation automatic control for example and by the proposed model and implemented EMS-MG, a simulation result is shown to illustrate the operation process of the simulation platform and present the benefits of the proposed method.
    01/2011;
  • Mao Meiqin, Dong Wei, Liuchen Chang
    [Show abstract] [Hide abstract]
    ABSTRACT: This paper proposed a novel platform for the simulation of Energy Management System for the Microgrid based on Multi-Agent System. The definitions of agents and the architecture of agents of the platform are discussed. And the proposed platform is integrated and implemented under C++ Builder environment in terms of server-client structure. To prove the effectiveness and benefits of this platform, an example of generation coordination in Microgrid is provided. The frequency calculating equation and models of elements used in the example are also introduced.
    01/2011;
  • Mao Meiqin, Sun Shujuan, Liuchen Chang
    [Show abstract] [Hide abstract]
    ABSTRACT: Electric vehicles (EVs) may play dual roles when they plug in a microgrid. They appear as loads during charging, meanwhile they may also be used as storage units to supply energy to the rest loads in the microgrid if the batteries have the sufficient spare energy. Considering the characteristic of bidirectional energy flow of EVs in a microgrid, this paper proposes the energy dispatch model and strategies for the microgrid including Wind generators, Photovoltaic systems, Battery storages, EVs and other local loads to analyze the impact of incorporating vehicles within and without microgrid on the economic operation of the microgrid. The simulation results indicate that incorporating EVs within the microgrid can not only minimize the capital cost of storages and reduce operation cost of the microgrid's operator, but also save the cost of EVs's owners.
    01/2011;
  • [Show abstract] [Hide abstract]
    ABSTRACT: This paper investigates the performance of electronic reactive power/energy meters by evaluating differences that arise as a result of (1) the distinct operating principles of the meter and (2) the presence of stationary and nonstationary power quality disturbances. The paper also includes a comparative study to determine the effectiveness of using orthogonal, bi-orthogonal, or reverse bi-orthogonal wavelets for such application. Moreover, the paper identifies the reactive power quantities required for accurate assessment and monitoring of reactive energy in the presence of power quality disturbances. Finally, the paper provides recommendations on reactive power and energy measurement for future generations of smart meters.
    IEEE Transactions on Power Systems 01/2011; 26(3):1263-1271. · 2.92 Impact Factor
  • Zijun Luo, M. Kaye, C. Diduch, Liuchen Chang
    [Show abstract] [Hide abstract]
    ABSTRACT: A phase locked loop method is proposed for fast estimation of utility grid frequency, for control and protection purposes in grid-connected power converters. Using a second order generalized integrator (SOGI) and a 'novel' frequency locked loop (nFLL), which makes the SOGI frequency adaptive, the proposed SOGI-nFLL detects small and large step changes in frequency with fast response and without large overshoot. In this paper, the SOGI-nFLL method is analyzed, simulated and implemented in a Field Programmable Gate Array (FPGA). Its performance is compared with the original SOGI-FLL using simulations and experimental data. The experimental results verify that the proposed method results in smoother transients for frequency detection that may be used to reliably activate over-frequency protection within a half cycle.
    Energy Conversion Congress and Exposition (ECCE), 2011 IEEE; 01/2011
  • [Show abstract] [Hide abstract]
    ABSTRACT: Power systems' operators have the task of maintaining the balance between the demand and generation of electric power. Much research and attention is being given to find more environmental friendly sources of power generation. Naturally, more power is required when the load is at its peak value, and this tends to be when the most non environmentally friendly sources of power generation are used. This paper proposes a new controller for peak load shaving by intelligently scheduling power consumption of domestic electric water heater using binary particle swarm optimization. Past studies show that similar demand side management programs were not successful because the impact that the load control has on the end users' comfort. In this study, Binary Particle Swarm Optimization (BPSO) finds the optimal load demand schedule for minimizing the peak load demand while maximizing customer comfort level. A simulation in Matlab is used to test the performance of the demand response program using field data gathered by smart meters from 200 households. The direct load control is shown to be an effective tool for peak shaving of load demand, shifting the loads to valleys and reducing the aggregated load of electricity without compromising customer satisfaction.
    Electric Power and Energy Conference (EPEC), 2010 IEEE; 09/2010

Publication Stats

1k Citations
47.00 Total Impact Points

Institutions

  • 1994–2011
    • University of New Brunswick
      • Department of Electrical & Computer Engineering
      Fredericton, New Brunswick, Canada
  • 2007
    • Hefei University of Technology
      Luchow, Anhui Sheng, China
    • East China JiaoTong University
      Jiangxi, Gansu Sheng, China
  • 2005
    • Huazhong University of Science and Technology
      Wu-han-shih, Hubei, China
  • 2000
    • Beijing Jiaotong University
      • School of Electrical Engineering
      Beijing, Beijing Shi, China
  • 1995
    • Tsinghua University
      Peping, Beijing, China