Huang Lipei

Filter design of restraining over-voltage and bearing current in induction motor fed by PWM inverter

PWM-inverter-induction-motor system will produce the over-voltage at the motor side and the strengthening of bearing current. R-C filter installed at the motor side is an effective method for restraining the over-voltage and bearing current. The method of choosing the parameters of filter is presented in the paper. The results of the simulations and experiments displayed in the paper proved the validity of the above method. The paper presented a simulation procedure, which can consider the mutual inductance and the mutual capacitance of the cables, and the test results of impedance frequency characteristic of several sets of induction motor.

Parallel-connected Interleaving CCM PFC Converter Based on Duty-Cycle Dynamic Distribution Controller

This paper presents a controller with duty-cycle dynamic distribution within parallel-connected PFC converters based on average-current control strategy, which can distribute the control duty-cycle automatically for each parallel-connected PFC converter to realize current balance by the difference from its reference current, and it can decrease and even eliminate the disturbance resulted by current-balancing process to total input current and output voltage. Moreover, a simple method is presented to interleave the currents of parallel-connected converters, and it can minish the size of filter and increase conversion efficiency based on only a single DSP. Taking three PFC modules in parallel for example, the scheme presented in this paper was validated with experimental results, and it would be a desirable digital solution for parallel-connected PFC converters in large power application.

All digital space vector PWM induction motor drive based on flux control

One space vector PWM (SVPWM) method based on closed-loop stator flux control is presented. To realize the method, an all digital voltage source inverter motor system is proposed, in which 2 processors are utilized, one is Hitachis H8/532 single chip processor, the other is TIs TMS320E15 DSP. The systems transient and steady state performance are investigated by means of digital simulation using a two axes (dc-qc-0) machine model. Experimental results show that the system has high performance.<<ETX>>

Main loop equivalent circuit of H-bridge power unit for EMI analysis

In order to construct high frequency equivalent circuit of main loop in large capacity converter, an H-bridge unit, which is widely used in large capacity inverter, was studied. The equivalent circuit of the busbar was established based on partial element equivalent circuit (PEEC) method. The parasitic parameters of the DC link capacitor tank were identified by least square curve fitting on transition process. Transient bridge voltage as excitation to the equivalent circuit, the simulation response current is very close to the measured current during the reverse recovery process. The result demonstrates that the accuracy of the equivalent circuit is reasonable and the modeling method is feasible and effective.

Design of grid-connected directly driven wave power generation system with optimal control of output power

This paper presents a directly driven wave power generation system which is connected to power grid composed of permanent magnetic linear generator(PMLG), generator side converter, grid side converter, controller and grid. Control strategies based on back to back converter structure was proposed: vector decoupling control was used to generator side converter aiming at optimize power extraction from wave energy; Grid voltage oriented control was used to grid side converter in order to make the current sinusoidal and realize unit power factor control. Since the DC link voltage has fluctuation using traditional method, a method with power feed forward was proposed to keep the DC link voltage stable and improve the dynamic response of the system. A simulation model was built for the whole system in Matlab/Simulink and simulation results verified that the proposed control strategy is feasible and effective.