The paper gives a variable angle pulse width modulation (PWM) adjustable-speed control strategy for four-phase 8/6 structure Switched Reluctance motor drive and introduces the developed prototype. Taking a four-phase 8/6 structure prototype for example, the variable angle PWM adjustable-speed control strategy is compared with the fixed angle PWM adjustable-speed control strategy that the turn-on angle of the main switches is fixed at -7.50 and the turn-off angle of the main switches is fixed at 22.50. It is shown that the four-phase 8/6 structure Switched Reluctance motor drive using the novel PWM control strategy has low peak value of phase current, high efficiency and the fixed switching frequency value of the main switches over the low rotor speed range.

The paper presents the three types of magnetic-flux paths at the condition of single-phase excitation and the two types of magnetic-flux paths at the condition of double-phase excitation while one phase winding is installed as NSNS. The calculated torque-angle characteristics of the machine are given with the different magnetic-flux paths.1

The paper presents the essential conditions for implementing the fault tolerant control of the Switched Reluctance motor drive system, such as the structure of the reluctance motor, the topology of the power converter, the rotor position detector, the current detector and the control strategies. The experimental tested results of the developed prototype with the fault tolerant control are given.

The paper presents the principles of two quadrants control, such as the traction control and regenerative braking control. The configuration of the Switched Reluctance motor drive for application in electric drive bicycle, such the schematic diagram of the system, the motor, the rotor position detector, the control logic for the operation at two quadrants and the two quadrants control scheme, are given. The comparison of the two types of the three-phase motors, such as the 12/8 structure motor and the 6/8 structure motor, at the same average electromagnetic torque in the turn numbers of per stator pole coil, in the resistance of the stator phase windings, and in the basic output frequency of the power converter, are made. Tested results of the developed prototype with the three-phase 12/8 structure motor, in the travel course with once charging, in the velocity, in the output torque, in the output power, in the systematic efficiency and in the peak value of phase current, are presented.