Chen Bo-shi

The different influences of four PWM modes on the commutation torque ripples in sensorless brushless DC motors control system

This paper introduces four PWM modes used in sensorless brushless DC motor control systems, and analyzes their different influences on the commutation torque ripple in detail. The authors then select the best PWM mode in four given types to reduce commutation torque ripple of BLDC motors. Simulation and experimental results prove that the selection is both correct and practical.

Influences of PWM mode on the current generated by BEMF of switch-off phase in control system of BLDC motor

In the control system of brushless DC (BLDC) motors, different PWM modes have different influences on the pulsating current generated by the BEMF (back electromotive force) of the switch-off phase, which may produce commutation error in the commutation control and reduce the reliability and the stability of the control system. This paper analyzes the generating theory of BEMF current and selects the best PWM mode to minimize its influence on the commutation control in five given types. Simulation and experimental results prove that the selection is correct and practical.

Influence of PWM modes on commutation torque ripples in sensorless brushless DC motor control system

This paper introduces four PWM modes used in the sensorless brushless DC motor control system, analyzes their different influences on the commutation torque ripple in detail, and selects the best PWM mode in four given types to reduce commutation torque ripple of Brushless OC(BLDC) motors. Simulation and experimental results show that the selection is correct and practical.

Stator-flux oriented continuous control of torque in induction motors

This paper analyzes dynamic equivalent circuit of induction motor and the relationship among inner fluxes, then presents a direct stator flux oriented continuous torque control (DSFOCTC) scheme of induction motor, which uses stator current vector control instead of voltage vector control. As a combination of direct torque control (DTC) and flux-oriented vector control, it achieves round stator flux and continuous dynamic torque control resulting in less torque ripple than that in DTC. It reduces the dependence on rotor parameters, and is especially insensitive to rotor resistance. Finally, an induction motor speed control system incorporating this novel scheme is given and checked by simulation.

Study on Rotor IGBT Chopper Control for Induction Motor Drive

Rotor chopper control is a simple and effective drive method for induction motor. This paper presents a novel IGBT chopper topology, which can both adjust rotor resistance and protect IGBT efficiently. Investigation on the quasi-transient state of the rotor rectifying circuit is made, and a nonlinear mapping between the equivalent resistance and the duty cycle is deduced. Furthermore, the method for determining the magnitude of the external resistor is introduced.

ANN-Based Identification of Steady-State Behavior Parameters of Composite Power Semiconductor Device Model

The paper describes the application of an ANN-based approach to the identification of the parameters relevant to the steady-state behavior of composite power electronic device models of circuit simulation software. The identification of model parameters of IGBT in PSPICE using BP neural network is illustrated.