A switched reluctance motor power converter and a control method thereof

Abstract

The invention relates to a switched reluctance motor power converter and a control method thereof. The novel power topology structure is adopted, compared with a traditional asymmetric half-bridge power converter, the power device is reduced, the switching loss is reduced and the overall system efficiency is improved. By using the novel power topology, the second electrolytic capacitor C2 can provide high voltage excitation state in the initial excitation process of SRM, so as to achieve the purpose of fast excitation, and the peak current in the conduction region is increased, which is beneficial to increase the output torque in the conduction region. In the off-off current mode, the load voltage of the phase winding is much higher than the back voltage of the DC input voltage, which is helpful to widen the conduction range and increase the output torque of the motor, and also makes the selection of the on-angle and off-angle more flexible. It can meet the large-scale application requirements of various single-phase, two-phase, three-phase or multi-phase switched reluctance motors in low-cost, low-speed and high-torque application occasions.

Description

technical field [0001] The invention relates to a switched reluctance motor power converter and a control method, belonging to the technical field of motor power conversion. Background technique [0002] The switched reluctance motor is a doubly salient pole structure, which has the advantages of high reliability, large starting torque, convenient control, and low cost. The power converter, as the component that undertakes the energy conversion work when the motor is running, is beneficial to the research of the power converter. The switched reluctance motor system is miniaturized and integrated. [0003] The typical power topology of switched reluctance motors is an asymmetrical half-bridge. Each bridge arm needs two diodes and two switching tubes. When the bridge arm increases, the power devices increase more, the cost is not easy to control, and the switching loss is more obvious. . The common type power converter has obvious advantages in this respect by reducing power...

AI Technical Summary

Problems solved by technology

[0003] The typical power topology of switched reluctance motor is an asymmetrical half-bridge. Each bridge arm needs two diodes and two switching tubes. When the bridge arm increases, the power devices increase more, the cost is not easy to control, and the switching loss is more obvious.

The common type power converter has obvious advantages in reducing power switching devices, reducing cost and reducing switching loss without affecting the performance of the motor. Sometimes there will be zero-voltage freewheeling of one of the phases, which may make it conduct for a full period, which will seriously affect the torque output and efficiency of the switched reluctance motor. In severe cases, the current in the conduction zone will be too large and the power device will be burned

Therefore, the traditional power converter with a common switch tube is only suitable for single-phase conduction mode, and is not suitable for high-speed operation, so that the turn-on interval is severely limited

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