Suppressing control of rising bus voltage for switched reluctance motor in braking operation

Switched reluctance motor (SRM) has simple construction and flexible control methods, which is easy to implement four-quadrant operations, and has a good ability of regenerative braking operation. However, when the motor works in the regenerative braking mode, the regenerative braking energy will have a great impact on the DC bus voltage, while the bus capacitors and power electronic devices may be damaged seriously due to the over voltage and over current. In the paper, regenerative braking process is analyzed, regenerative braking energy on the impact of DC bus voltage is researched, and the control strategy that altering the turn-on angle to make the active phase windings operate in a small motoring region is proposed, which consumes the regenerative braking energy and reduce the rising bus voltage. PWM duty-cycle is also investigated in details. Essential braking torque can generate, the impact of braking energy feedback on the bus voltage can be reduced in the process of regenerative braking, and the reliability and security of the braking operation can be improved. The corresponding simulation and experimental results are presented to verify the effectiveness and practicality of the proposed method.