Single-phase grid-connected zero-torque integrated charging structure of three-phase series winding and charging method

Abstract

The invention discloses a single-phase grid-connected zero-torque integrated charging structure of a three-phase series winding and a charging method, and belongs to the field of electric automobiles. And under a static coordinate system of the open winding motor, a proportional-resonant regulator is adopted to control single-phase grid-connected current. Wherein the 0-axis current can share the component of the grid-connected current on the alpha-beta axis, the pulsating current is reduced, and the loss of the permanent magnet is reduced. After four sets of bridge arm output voltage instructions are obtained through the alpha beta 0 three-axis current control algorithm, a driving signal of an inverter is obtained through a carrier wave comparison method, and then overall single-phase grid-connected charging control is achieved. According to the charging scheme provided by the invention, the current stress of the bridge arm can be uniformly distributed, and the loss of the whole bridge arm is reduced to the minimum under the condition that the single-phase charging current is constant. Besides, for an open winding motor containing a permanent magnet, the scheme can greatly reduce magnetizing and flux weakening current under the condition that the overall charging power is not changed, and the loss of the permanent magnet is small.

Description

technical field [0001] The invention belongs to the field of electric vehicles, and more specifically relates to a single-phase grid-connected zero-torque integrated charging structure and charging method of three-phase series windings. Background technique [0002] Currently, electric vehicles are developing very rapidly. In terms of electric drive, the poor high-speed power performance and low efficiency of the motor have become the current pain points to be solved. Patent CN108258976B proposes an open-winding motor driver topology and its modulation method. This topology can increase the DC bus voltage utilization rate by 1.74 times, and the high-speed power performance of the motor is significantly improved. Patent CN111786613B proposes its fault tolerance method with the help of the three-phase series topology. It can be said that compared with the traditional three-phase half-bridge topology, the series winding topology is better in driving performance. In addition, ...

AI Technical Summary

Problems solved by technology

This method is based on the traditional three-phase half-bridge topology. The rotor of the motor is fixed by means of pulsating current to realize zero-torque charging. However, this scheme makes the grid-connected current all borne by the pulsating current. , will cause a large loss to the permanent magnet, and the current stress of the bridge arm cannot be shared equally, the conduction loss is large, and the charging upper limit power is limited

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