Car permanent magnet synchronous motor control system and method

Abstract

The invention provides a brand new permanent magnet synchronous motor control method. A control system applied by the method comprises a torque command input unit, a torque-current lookup unit, a cross decoupling regulation unit, a space vector pulse width modulation unit, an inverter unit, a weak magnetic regulation unit and a permanent magnet synchronous motor unit, wherein the torque-current lookup unit performs analysis according to the output result of current weak magnetic regulation and a torque command and acquires an AC-DC shaft current command through lookup, and the lookup manner is irrelevant to the rotating speed so as to improve the convenience and the accuracy of torque lookup; meanwhile, the cross decoupling regulation unit performs cross PI (Proportional-Integral) regulation on the difference between the AC-DC shaft current command and actual current feedback so as to reduce the influence of cross coupling of the motor per se at high speed and improve the high-speed stability of the motor; and the weak magnetic regulation unit calculates the amplitude of voltage vector according to the current AC-DC shaft voltage reference command, performs PI regulation on the amplitude and the maximum available voltage vector amplitude in the current busbar voltage and automatically outputs a weak magnetic reference current command to conveniently enlarge the motor speed regulation range.

Description

technical field [0001] The invention belongs to the field of drive motor systems for new energy vehicles, and in particular relates to a torque control mode, a field-weakening adjustment mode and cross decoupling control of a permanent magnet synchronous motor. Background technique [0002] For the drive system of new energy vehicles, a permanent magnet synchronous motor system with high efficiency and high power density is generally used for driving. At the same time, the low-speed constant torque and high-speed constant power characteristics of the permanent magnet synchronous motor also meet the operating characteristics of the car. In order to meet the speed range and control accuracy of the whole vehicle, it is generally required that the motor system adopts a torque control method and has a high speed regulation range, thus putting forward higher requirements for the motor control method. At present, the current-voltage regulation of the permanent magnet synchronous mo...

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Problems solved by technology

This method has great restrictions on the high-speed operation of the motor, which is easy to cause system instability

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