Permanent magnet synchronous motor control method and system

Abstract

The invention discloses a permanent magnet synchronous motor control method and system, wherein current pulsation is reduced and steady-state performance is improved while common-mode voltage is suppressed compared with a traditional single-vector MPC, and algorithm complexity is reduced and calculated amount is reduced compared with an existing double-vector MPC. The method comprises the steps ofcollecting mechanical and electrical parameters of a permanent magnet synchronous motor at the current moment; calculating to acquire a rotation reference voltage vector of a synchronous rotation coordinate system, and converting the rotation reference voltage vector into a static reference voltage vector of a static coordinate system; determining a sector of the static reference voltage vector in a plane where a basic voltage vector is located; selecting two effective vectors from the plane vectors according to the sector, and synthesizing to acquire a synthesized vector; calculating a firstdistance and a second distance from the static reference voltage vector to the side where the zero vector and the synthesized vector are located; selecting an alternative vector according to the first distance and the second distance; and calculating the action time of the alternative vector, determining the action time of all the basic voltage vectors, and controlling the permanent magnet synchronous motor.

Description

technical field [0001] The invention relates to the field of motors, in particular to a control method and system for a permanent magnet synchronous motor. Background technique [0002] Permanent-magnet synchronous motor (Permanent-Magnet Synchronous Motor, PMSM) has been widely used in electric vehicles and other fields due to its advantages of high power density, low cost, high efficiency, and good reliability. In the PMSM control system, the common mode voltage will produce overvoltage stress on the insulation between the motor winding and the motor bearing, and the magnitude of the common mode voltage is an important indicator to measure the intensity of electromagnetic interference. [0003] Model predictive control (Model Predictive Control, MPC) is used for common-mode voltage suppression with its many advantages. Among the eight basic voltage vectors provided by the two-level voltage source inverter, the common-mode voltage amplitude generated by the zero vector is ...

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Problems solved by technology

[0004] Although the common-mode voltage suppression method of the traditional single-vector MPC does not use a zero vector in each control cycle, which significantly suppresses the common-mode voltage, but because no zero vector is used and there is only one vector in one control cycle, the current ripple is large and the steady-state performance is poor. ; In the existing two-vector MPC, some algorithms first select the first effective vector through the cost function, and the second vector is selected from the vectors adjacent to the first effective vector, and the combined action time of the two sets of vectors is calculated and then substituted into the cost function Optimization, this type of method requires multiple calculations to optimize, the algorithm is complex, and the amount of calculation is large

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