N.C. Cheung

The University of Hong Kong, Hong Kong, Hong Kong

Are you N.C. Cheung?

Claim your profile

Publications (114)100.06 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: Linear switched reluctance actuator (LSRA) is of great potential using in kind of high-force linear applications such as automotive suspension system. In this study, an electrical controlled active suspension system is built. Bi-directional power amplifier is used to supply power to and absorb generated energy from linear actuator based on the movement requirement. The linear motions are accomplished by retracting and extending the LSRA. With regard to the established electromagnetic suspension system, a real-time control algorithm is developed. Sliding model technique with adaptive mechanism is studied to compensate the system non-linearities and external road profile. Experiments are conducted at the laboratory to present the high performance of proposed active suspension system.
    IET Electric Power Applications 01/2015; 9(1):50-59. DOI:10.1049/iet-epa.2014.0115 · 1.31 Impact Factor
  • J.F. Pan, Yu Zou, Norbert Cheung, Guangzhong Cao
    [Show abstract] [Hide abstract]
    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. DOI:10.1016/j.ijepes.2014.04.017 · 3.43 Impact Factor
  • J.F. Pan, Yu Zou, Norbert Cheung, Guang-Zhong Cao
    [Show abstract] [Hide abstract]
    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; 29(10):1-1. DOI:10.1109/TPEL.2013.2292069 · 5.73 Impact Factor
  • J.F. Pan, F.J. Meng, N.C. Cheung
    [Show abstract] [Hide abstract]
    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. DOI:10.1109/TMAG.2013.2285377 · 1.21 Impact Factor
  • J.F. Pan, Yu Zou, N.C. Cheung
    [Show abstract] [Hide abstract]
    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. DOI:10.1109/TMAG.2013.2281477 · 1.21 Impact Factor
  • Yu Zou, Ka-Wai Eric Cheng, Norbert C. Cheung, Jianfei Pan
    [Show abstract] [Hide abstract]
    ABSTRACT: In this paper, a skewed teeth structure is proposed for the linear switched reluctance motor (LSRM). First, the normal force, as the main source of the machine deformation as well as the acoustic noise, is analyzed theoretically. Second, the skewed LSRM is designed, and the angle of the skewed structure is analyzed and optimized. Then, the normal force output of the LSRM is calculated using the finite element method (FEM), and the deformation results for the proposed machine are obtained. The relationship of the normal force and the skewed angle is derived. Finally, the experimental results demonstrate that the acoustic noise is reduced, which is a testament to the effectiveness of the proposed structure.
    IEEE Transactions on Magnetics 01/2014; 50(11):1-4. DOI:10.1109/TMAG.2014.2323420 · 1.21 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: This paper presents an inductance derivative estimation method of linear switched reluctance actuator (LSRA) employing tracking-differentiating technology. The inductance of LSRA is highly nonlinear and varies with phase current and translator position. To achieve direct force control, the derivative of inductance must be estimated to generate required phase currents. The inductance profile of LSRA is obtained from finite element analysis calculation. Tracking differentiator is introduced to track the inductance and its derivative for further control purpose. A simple Proportional-Integral control with compensation unit using the estimated inductance derivative is used to examine the effectiveness of the estimation of inductance derivative.
    IEEE Transactions on Magnetics 01/2014; 50(11):1-4. DOI:10.1109/TMAG.2014.2334312 · 1.21 Impact Factor
  • S. W. Zhao, L. N. Luo, L. Q. Yang, N. C. Cheung
    [Show abstract] [Hide abstract]
    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
  • [Show abstract] [Hide abstract]
    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
  • [Show abstract] [Hide abstract]
    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, W. X. Wang, X. Y. Yang, N. C. Cheung
    [Show abstract] [Hide abstract]
    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
  • Yu Zou, Eric Cheng, Norbert Cheung, J. F. Pan
    [Show abstract] [Hide abstract]
    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
    [Show abstract] [Hide abstract]
    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
  • J. F. Pan, F. J. Meng, Wanlai Jiang, Norbert C. Cheung
    [Show abstract] [Hide abstract]
    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
  • [Show abstract] [Hide abstract]
    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. DOI:10.1109/TVT.2012.2222682 · 2.64 Impact Factor
  • Hoi-Wai Chow, N.C. Cheung
    [Show abstract] [Hide abstract]
    ABSTRACT: Permanent magnet linear motors are a type of linear motors that are generally used in precision motion control applications. However, the position of motor is easily disturbed by external force, disturbance, and variation in parameters of plant. Therefore, the construction of the high-precision linear motion system is a difficult task. This paper implements a modified disturbance observer and compensator, which includes a novel variable gain, to overcome the effects of unknown parameters of the motor, to minimize the effect of the disturbance, and to reduce the response time of the disturbance. This compensated linear motor is further controlled by the internal model reference control algorithm so that the position of the motor can be tracked with expected response precisely. The authors conducted the experiments and verified the feasibility of the high-precision positioning control. Compared with the case of normal disturbance compensator, the experimental results also illustrate the improvements of the novel variable gain, which reduces the response time toward the command signal and the external disturbance.
    IEEE Transactions on Industrial Electronics 01/2013; 60(1):139-150. DOI:10.1109/TIE.2012.2185015 · 6.50 Impact Factor
  • [Show abstract] [Hide abstract]
    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. DOI:10.1109/TMAG.2012.2198794 · 1.21 Impact Factor
  • [Show abstract] [Hide abstract]
    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. DOI:10.1109/TMAG.2012.2202094 · 1.21 Impact Factor
  • J. F. Pan, Norbert C. Cheung, Yu Zou
    [Show abstract] [Hide abstract]
    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. DOI:10.1109/TMAG.2012.2202376 · 1.21 Impact Factor
  • J. F. Pan, Norbert C. Cheung, Yu Zou
    [Show abstract] [Hide abstract]
    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. DOI:10.1109/TMAG.2012.2202377 · 1.21 Impact Factor

Publication Stats

599 Citations
100.06 Total Impact Points

Institutions

  • 2009–2015
    • The University of Hong Kong
      • Department of Electrical and Electronic Engineering
      Hong Kong, Hong Kong
  • 2001–2014
    • The Hong Kong Polytechnic University
      • • Department of Electrical Engineering
      • • Power Electronics Research Centre
      Hong Kong, Hong Kong
  • 2011
    • GuangDong University of Technology
      Shengcheng, Guangdong, China
  • 2009–2011
    • Shenzhen University
      Bao'an, Guangdong, China
  • 2001–2010
    • South China University of Technology
      Shengcheng, Guangdong, China
  • 2001–2003
    • The Hong Kong University of Science and Technology
      • Department of Electronic and Computer Engineering
      Chiu-lung, Kowloon City, Hong Kong