A detection and protection circuit and method for phase-to-phase short circuit of switched reluctance motor

Abstract

The invention provides a detecting and protecting circuit and method for an inter-phase short circuit of a switch reluctance motor. The detecting and protecting circuit is provided with an asymmetric half-bridge power converter, a current sampling circuit, a current sampling and amplifying circuit, a microprocessor CPU and a two-input AND gate. A switch reluctance motor inter-phase short circuit distinguishing algorithm is set in the CPU, according to the detection of the running states of the switch reluctance motor, short-circuit current detection pulses of lower switch power tubes, corresponding to all the running states, of a non-work phase are triggered in sequence through the CPU, a short-circuit current caused by the inter-phase short circuit flows to the lower switch power tubes of the non-work phase in series and is fed back to the CPU through the current sampling circuit and the current sampling and amplifying circuit, the short-circuit current is compared with a set threshold current, whether short circuit happens to the switch reluctance motor or not is judged based on a comparison result, and therefore inter-phase short circuit protection of the switch reluctance motor is achieved.

Description

technical field [0001] The invention relates to the application of an asymmetrical half-bridge power converter in a switched reluctance motor, in particular to a detection and protection circuit for a phase-to-phase short circuit of a switched reluctance motor and a method thereof. Background technique [0002] The switched reluctance motor has simple and firm structure, reliable operation and high efficiency. Compared with the traditional AC and DC speed control system, the switched reluctance motor drive system composed of it has many advantages, such as: large starting torque, wide speed range, Flexible control, convenient to realize four-quadrant operation, strong regenerative braking ability, high efficiency in a wide range of speed and power, which is conducive to energy saving and consumption reduction; it can work at extremely high speed; it can run in open phase, Strong fault tolerance and so on. Asymmetric half-bridge power converters are widely used in the field ...

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