Maximum torque current ratio control method for built-in permanent magnet synchronous motor

Abstract

The invention discloses a maximum torque current ratio control method for a built-in permanent magnet synchronous motor. The method comprises the following steps: 1) obtaining three-phase stator currents ia, ib and ic of a motor through sampling, then, obtaining currents idr and iqr under d and q coordinate systems through coordinate transformation, and obtaining a rotor position angle theta and amechanical rotating speed omega r of the motor through a rotary transformer; 2) extracting derivative information dTe / dbeta of the torque to the current angle, taking the derivative information dTe / dbeta as the input of an integrator, generating a given value idref of the d-axis current, and obtaining a given value iqref of the q-axis current under the given torque Teref; adding a feedforward decoupling item to the output of the PI controller to obtain a d-axis stator voltage reference value vdref and a q-axis stator voltage reference value vqref; and 3) adopting a voltage space vector pulsewidth modulation method to obtain six paths of PWM pulse trigger signals, and controlling the two-level voltage source type inverter to work so as to drive the motor to rotate.

Description

technical field [0001] The invention relates to the field of motor control, in particular to a method for controlling the maximum torque-to-current ratio of a built-in permanent magnet synchronous motor based on virtual complementary square wave signal injection. Background technique [0002] The built-in permanent magnet synchronous motor (Permanent Magnet Synchronous Motor, PMSM) has the characteristics of compact structure and high power density, and is widely used in the drive system of electric vehicles. For the interior permanent magnet synchronous motor, in order to make full use of the reluctance torque, a maximum torque current ratio (Maximum Torque Per Ampere, MTPA) control method is often used. The determination of the maximum torque-to-current ratio operating point depends on the motor parameters. However, the parameters of the interior permanent magnet synchronous motor are affected by the environment, flux saturation and cross-coupling, showing a high degree o...

AI Technical Summary

Problems solved by technology

However, since the torque is a trigonometric function of the current angle, the remaining part is considered to be the derivative information of the torque to the current angle, which is inaccurate, so it is difficult to obtain an accurate maximum torque-current ratio operating point

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