Permanent-magnet synchronous-motor open-winding fault-tolerant direct torque control method based on improved SVPWM

Abstract

The invention discloses a permanent-magnet synchronous-motor open-winding fault-tolerant direct torque control method based on improved SVPWM. The method comprises the following steps of when an inverter switch tube has an open circuit fault, cutting off connection between a motor port and the fault inverter switch tube, connecting the motor port to a power supply midpoint, and using the remainingswitch tube to carry out fault-tolerant reconstruction on a system topology; through a PI controller, outputting a given torque; using a ''current method'' to estimate a stator flux linkage; and through the difference value of the given torque and an estimated torque, acquiring the variable quantity d delta of a load angle, using a maximum torque current ratio control method to give a reference stator flux linkage, and based on that, calculating a given reference voltage vector. Through the remaining switch tube, improved spatial voltage vector pulse width modulation reconstruction is performed. A double-inverter PWM control signal with a fixed switch frequency is output to an inverter. Under the open circuit fault of the switch tube, the safe and stable operation of a system under the fault is guaranteed, and the system has a good stable state and dynamic performance.

Description

technical field [0001] The invention relates to a three-phase permanent magnet synchronous motor control technology, in particular to an open-winding fault-tolerant direct torque control (DTC) method based on an improved SVPWM for a three-phase permanent magnet synchronous motor, which is suitable for aerospace vehicles, industrial production and manufacturing, New energy vehicles and other fields. Background technique [0002] In people's industrial production and daily life, devices that convert electrical energy into mechanical energy are often used, that is, AC motor servo systems. With the development of power electronics technology, microelectronics technology, microcomputer technology, sensor technology, rare earth permanent magnet materials and motor control theory, AC servo control technology has a wide speed range, high steady-state accuracy, high torque output, Good technical performance such as fast dynamic response and four-quadrant operation. In recent years, ...

AI Technical Summary

Problems solved by technology

[0008] The purpose of the present invention is to provide a direct torque control method suitable for permanent magnet synchronous motors to solve the problem of stable operation of permanent magnet synchronous motor systems under the open circuit fault of the inverter switch tube

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