N.C. Cheung

The Hong Kong Polytechnic University, Hong Kong, Hong Kong

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Publications (103)86.04 Total impact

  • J.F. Pan, Yu Zou, Norbert Cheung, Guangzhong Cao
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    ABSTRACT: A direct-drive generator based on linear switched reluctance principle is investigated for wave energy utilization. Integrated with the sensorless technique, the direct-drive generator has the characteristics of low cost and robustness, and the power generation control system is especially suitable for the operation under hostile working environments since restrictions of physical sensors are eliminated. Simulation analysis based on the finite element methods (FEM) and joint simulation are carried out for performance analysis of the power generation control system, including position estimation, open loop turn-on and turn-off position optimization and closed loop current regulation. Experimental results validate the effectiveness of the position estimation scheme for the sensorless, linear switched reluctance generator based power generation control system.
    International Journal of Electrical Power & Energy Systems 11/2014; 62:29–37. · 3.43 Impact Factor
  • J.F. Pan, Yu Zou, Norbert Cheung, Guang-Zhong Cao
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    ABSTRACT: This paper discusses about voltage output ripple reduction and error minimization for the direct-drive, linear switched reluctance generator (LSRG) based wave power generation system. First, the concept of LSRG based wave power generation system is studied. According to the characteristics of the LSRG, the suitable drive circuit dedicated to proper current excitation and generation is established. Second, the reasons that cause voltage output ripples are investigated. To reduce the remarkable ripples from phase current commutations, a current distribution function (CDF) is proposed based on minimized copper loss principle. Third, the dual-loop control strategy with current and voltage as the inner and outer loop is constructed, implemented with the proposed CDF. Theoretical bases of the control strategy are derived. The simulation results prove that the proposed control algorithm is capable of voltage ripple suppression and error reduction within the range of ±0.5 volts over the entire operation speed for wave energy extraction, validated by experimental verification.
    IEEE Transactions on Power Electronics 10/2014; · 5.73 Impact Factor
  • J.F. Pan, Yu Zou, N.C. Cheung
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    ABSTRACT: An integrated rotary–linear machine based on switched reluctance principle is investigated. The characteristics of the motor are analyzed by finite-element methods, with particular emphasis on the coupled magnetic paths. Results from numerical calculation are verified by the hardware experiment. The simple yet effective decoupling algorithm for the independent position control of both rotary and linear axes is proposed. Implemented with the proportional–integral-differential algorithm, the motor is capable of high-precision rotary and linear position tracking with the steady error within 0.3$^{circ}$ and $10~mu{rm m}$, respectively.
    IEEE Transactions on Magnetics 02/2014; 50(2):761-764. · 1.21 Impact Factor
  • J.F. Pan, F.J. Meng, N.C. Cheung
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    ABSTRACT: Core loss is one of the key factors for performance evaluation of switched reluctance machines. In this paper, core loss analysis of the planar switched reluctance motor (PSRM) is calculated based on the 3-D time-stepping finite element methods. The numerical analysis for the computation of the core loss is discussed, also its transient and average core loss in the mover and the stator are calculated. The corresponding experiments of measurement loss for a PSRM prototype are conducted and the results validate the accuracy from the numerical analysis. It can be concluded that core loss dominates around the corner of the mover and stator cores.
    IEEE Transactions on Magnetics 02/2014; 50(2):813-816. · 1.21 Impact Factor
  • J. F. Pan, F. J. Meng, Wanlai Jiang, Norbert C. Cheung
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    ABSTRACT: This paper investigates the fuzzy control method for the linear switched reluctance motor (LSRM) drive system. Modeling of the LSRM is constructed based on the finite element method (FEM) environment Maxwell and the control system is analyzed by the co-simulation environment with Simplorer. Both the performance of the fuzzy proportional integral differential (PID) controller and the traditional PID controller are compared. The simulation results prove that the fuzzy PID controller yields faster rising time and smaller overshoot, compared with the traditional PID controller.
    2013 5th International Conference on Power Electronics Systems and Applications (PESA) New Energy Conversion for the 21st Century; 12/2013
  • S. W. Zhao, W. X. Wang, X. Y. Yang, N. C. Cheung
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    ABSTRACT: Linear Switched Reluctance Motor (LSRM) is a potential candidate of traditional rotary-linear motors on many industrial applications. In this paper, a LSRM design procedure is presented to obtain the main dimensions of a LSRM. By adjusting some dimensions detailed, performance of a LSRM can be improved based on the main dimensions from the design procedure. The generated force is improved by using different pole-arc of mover and stator in this paper. Some simulations of a LSRM are performed in the platform of Maxwell. The results demonstrate that design procedure is effective for LSRM.
    2013 5th International Conference on Power Electronics Systems and Applications (PESA) New Energy Conversion for the 21st Century; 12/2013
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    ABSTRACT: In this paper, a multi-modular linear switched reluctance actuator (LSRA) is proposed in the active suspension application for its robust structure and fast dynamic response. In order to meet the requirements by active suspension system, a design optimization method, which aims to improve the average force, reduce the force ripple and increase the force density, is described in details. Based on the preliminary design of LSRA, the stator pole width and translator pole width are selected as the optimization variables. Constraints on both pole widths are then discussed by considering the feasible triangle of LSRA and suspension volume limitation. Furthermore, the effects of both pole widths on average force, force ripple and force density are analyzed. Optimization results under various weight factor combinations are obtained and demonstrated by comparing the value of optimization objective function.
    2013 5th International Conference on Power Electronics Systems and Applications (PESA) New Energy Conversion for the 21st Century; 12/2013
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    ABSTRACT: A controller for the linear compressors propelled by the linear switched reluctance actuators is developed and presented in this paper. The controller is based on DSP TMS320F28335. It consists of the DSP circuit, the protection circuit, the multi-output DC supply, the current sensing circuit, the driving circuit, the AC-DC rectifier circuit, and the actuator converter. The double-loop control scheme is proposed and implemented. One of which is the closed-loop current control and the other is the closed-loop frequency control. The architecture of the controller and the control scheme are illustrated in the paper. The prototype of the proposed controller is developed. The experimental results demonstrate that the proposed controller is satisfactory and able to match the linear compressors propelled by linear switched reluctance actuators.
    2013 5th International Conference on Power Electronics Systems and Applications (PESA) New Energy Conversion for the 21st Century; 12/2013
  • S. W. Zhao, L. N. Luo, L. Q. Yang, N. C. Cheung
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    ABSTRACT: In this paper, a passivity-based control (PBC) algorithm with disturbance reject is proposed to obtain precise position control of a Linear Switched Reluctance Motor (LSRM) driving system in short distance applications. In the framework of the two-time-scale analysis, the whole system is decomposed into two reduced-order models. With the models, an improved PBC algorithm is designed to reject the nonlinear friction in the outer loop. Three simulations are performed and the results demonstrate the improved control algorithm is effective for the LSRM position tracking system in short distance applications.
    2013 5th International Conference on Power Electronics Systems and Applications (PESA) New Energy Conversion for the 21st Century; 12/2013
  • Yu Zou, Eric Cheng, Norbert Cheung, J. F. Pan
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    ABSTRACT: In this paper, a novel method to regulate the angle displacement of solar panel for photovoltaic (PV) power generation based on the three phase curved switched reluctance motor (SRM) is proposed. The mechanical structure of the tracking system and mathematic models of curved SRM are designed and elaborated. The electromagnetic features are analyzed by using finite element method (FEM). Both open loop and closed loop control mode of the curve SRM are described and simulated through co-simulation approach, respectively. Simulation results testify the feasibility of the proposed tracking method. This method is expected to be applied in tracking systems for PV or concentrating photovoltaic (CPV) power generation in the future.
    2013 5th International Conference on Power Electronics Systems and Applications (PESA) New Energy Conversion for the 21st Century; 12/2013
  • J. F. Pan, B. B. Yang, Wanlai Jiang, Norbert C. Cheung
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    ABSTRACT: The simulation and optimization of a direct drive rotary motor (DDRM) for optimized torque output has been designed in this paper, which presents higher efficiency and better torque-to-volume ratio. Lacking of enough torque and precision, the traditional angular displacement control system is typically composed of a rotary motor and a moving platform from a series of complex mechanical transformations. The DDRM is an ideal alternative, deriving from the linear permanent magnetic motor, which features large torque, high precision, efficiency and it can be controlled directly and independently. Thus, to improve the output torque and the output volume ratio, this paper models the DDRM based on the finite element method (FEM) and presents the optimization procedures analytically. The simulation results show that torque output and the torque output volume ratio can be increased by 0.4 Nm and 12% respectively.
    2013 5th International Conference on Power Electronics Systems and Applications (PESA) New Energy Conversion for the 21st Century; 12/2013
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    ABSTRACT: In this paper, an active suspension system utilizing a low-cost high-performance linear switched reluctance actuator with proportional-derivative (PD) control is presented. With the tracking differentiator (TD) calculating the displacement and its derivatives directly under the presence of noise, velocity and acceleration can be evaluated, and accurate position control can be achieved. Comparison is made between linear and nonlinear PD control methods in terms of various system parameters and road profiles. A nonlinear PD controller with better dynamic responses is evaluated and developed for real-time suspension application. The proposed PD control schemes are simulated, tested, and analyzed to prove its robustness and reliability. Finally, a quarter-car active suspension system prototype is built to demonstrate the effectiveness of the proposed control schemes with experiment results.
    IEEE Transactions on Vehicular Technology 02/2013; 62(2):562-572. · 2.64 Impact Factor
  • J. F. Pan, Norbert C. Cheung, Yu Zou
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    ABSTRACT: An improved force distribution function (FDF) of linear switched reluctance motors (LSRMs) based on nonlinear inductance modeling for force ripple minimization and smooth speed operation is proposed. Nonlinear inductance profile is divided into three segments with a K factor that depicts current effect on inductance of the LSRM. Speed controller based on the proposed FDF and the nonlinear inductance model is constructed. Both simulation and experimental results verify the proposed FDF with the nonlinear inductance modeling effectively reduce force ripples with uniform speed response.
    IEEE Transactions on Magnetics 11/2012; 48(11):3064-3067. · 1.21 Impact Factor
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    ABSTRACT: Force ripple is the main disadvantage of conventional linear switched reluctance actuators/motors (LSRAs/LSRMs). Based on finite element analysis (FEA), a new method to minimize force ripple is proposed for multimodular LSRAs/LSRMs in this paper. First, the force distribution of an LSRA/LSRM module is computed by using FEA. Then, the scheme of the spatial distribution of modules is developed. Finally, the modular spatial displacement is optimized to minimize force ripple. The computed results based on the FEA demonstrate the proposed method. The proposed method does not require any change in both module design and motor control. Thus, it is simple, cost-low, feasible, and effective.
    IEEE Transactions on Magnetics 11/2012; 48(11):3859-3862. · 1.21 Impact Factor
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    ABSTRACT: The novel switched reluctance generator (SRG) with hybrid magnetic paths is developed for wind power generation in this paper. For the proposed SRG, there is no mutual coupling between phase windings. The proposed SRG has the longitudinal magnetic structure at the completely aligned position. However, it has the transverse and longitudinal magnetic structure at the unaligned position. Thus, three-dimensional finite element computation is needed in the design. The computed results based on three-dimensional finite-element analysis (FEA) are shown in the paper. Furthermore, the experimental results of the prototype demonstrate that the proposed SRG is feasible and effective.
    IEEE Transactions on Magnetics 11/2012; 48(11):3863-3866. · 1.21 Impact Factor
  • J. F. Pan, Norbert C. Cheung, Yu Zou
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    ABSTRACT: A transverse-flux tubular linear machine with novel gear-shaped teeth for high force density is proposed. The teeth can be formed by silicon steel laminations or permanent magnets for a tubular linear switched reluctance or tubular linear hybrid motor. With the unique improved teeth structure and short magnetic circulation paths, larger propulsion force output can be obtained with reduced mover weight and volume. Simulation based on finite element method (FEM) verifies the validity of the proposed machine design. The proposed machines are compared with other transverse-flux linear machines. Results show that the proposed tubular motors exhibit better output performance with a higher force-to-volume ratio.
    IEEE Transactions on Magnetics 11/2012; 48(11):3339-3343. · 1.21 Impact Factor
  • Source
    J F Pan, Norbert C Cheung, Yu Zou
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    ABSTRACT: The design of an X-Y table applying direct-drive linear switched reluctance motor (LSRM) principle is proposed in this paper. The proposed X-Y table has the characteristics of low cost, simple and stable mechanical structure. After the design procedure is introduced, an adaptive position control method based on online parameter identification and pole-placement regulation scheme is developed for the X-Y table. Experimental results prove the feasibility and its priority over a traditional PID controller with better dynamic response, static performance and robustness to disturbances. It is expected that the novel two-dimensional direct-drive system find its applications in high-precision manufacture area.
    ISA Transactions 09/2012; · 2.26 Impact Factor
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    ABSTRACT: A direct instantaneous force control with improved efficiency for the linear switched reluctance actuator (LSRA) is proposed in this paper. Four-quadrant operation is investigated for application in the active suspension system. Force ripple minimization is considered as the primary objective due to the direct impact on passenger ride comfort. An adaptive force distribution function based on the instantaneous force feedback is proposed to achieve a ripple-free system. The choice of switching parameters for improved operation efficiency is examined. The optimal switching positions are online adjusted with respect to the force demand. Simulation and experimental results are presented to verify the effectiveness of the proposed control strategy.
    IEEE Transactions on Vehicular Technology 05/2012; 61(4):1567-1576. · 2.64 Impact Factor
  • Y.J. Bao, K.W.E. Cheng, N.C. Cheung, S.L. Ho
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    ABSTRACT: Renewable energy sources require power electronics for the power processing in order to enhance the operation and performance. In this study, a method of harnessing wind power on-board of an electric vehicle using switched reluctance generator (SRG) coupled to a wind turbine, which is mounted on the vehicle is discussed. The wind turbine integrated with SRG poses a number of challenges for vehicle application as the location and the design are special. The present investigation aims at acquiring the first hand experience in the practical implementation of such a system for on-board power generation. Various configurations of wind turbines are studied. The experimental test from a prototype is presented to validate the theoretical predictions.
    IET Power Electronics 01/2012; 5(8):1262-1269. · 1.32 Impact Factor
  • Source
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    ABSTRACT: An accurate estimation of flux linkage characteristics is very important during the preliminary design stage and high-performance control of linear switched reluctance motor (LSRM). In this paper, longitudinal and transversal end-effects of a double-side LSRM are studied using analytical method and finite element analysis (FEA). The estimation discrepancy introduced by both end-effects is presented respectively by investigating their sensitivities to machine parameters, such as excitation level, translator position, and stack length.
    IEEE Transactions on Magnetics 11/2011; · 1.21 Impact Factor

Publication Stats

442 Citations
86.04 Total Impact Points

Institutions

  • 2005–2014
    • The Hong Kong Polytechnic University
      • Department of Electrical Engineering
      Hong Kong, Hong Kong
  • 2010–2012
    • Shenzhen University
      Bao'an, Guangdong, China
  • 2001–2010
    • The University of Hong Kong
      • Department of Electrical and Electronic Engineering
      Hong Kong, Hong Kong
  • 2001–2003
    • The Hong Kong University of Science and Technology
      Chiu-lung, Kowloon City, Hong Kong