Parameter recognition method for permanent magnet synchronous motor of electric vehicle

Abstract

The invention discloses a parameter recognition method for a permanent magnet synchronous motor of an electric vehicle. The method comprises the steps of judging whether the permanent magnet synchronous motor of the electric vehicle needs parameter recognition or not; when parameter recognition needs to be carried out, injecting a low-frequency small-amplitude sinusoidal current signal into quadrature-axis expected current of the permanent magnet synchronous motor, and automatically adjusting the quadrature-axis expected current, direct-axis expected current, quadrature-axis voltage and direct-axis voltage by an adjuster; the rotating speed and position signals of the permanent magnet synchronous motor are measured through a rotating speed sensor, three-phase current of the permanent magnet synchronous motor is collected through a current sensor and converted into direct-axis feedback current and quadrature-axis feedback current, and data are transmitted to a parameter recognition linkin real time; and performing parameter recognition on the permanent magnet synchronous motor through the parameter recognition link until the parameters converge. According to the method, parameter recognition can be carried out under any operation state of the motor, the control requirements of the permanent magnet synchronous motors with different structures can be well met, the identified parameters are accurate, and the application range is wide.

Description

technical field [0001] The invention relates to the technical field of motor control, in particular to a parameter identification method of a permanent magnet synchronous motor of an electric vehicle. Background technique [0002] Permanent magnet synchronous motors are widely used in the field of new energy vehicles and industrial fields due to their high efficiency and high power density. During the operation of the permanent magnet synchronous motor, the four important parameters of direct axis inductance, quadrature axis inductance, stator resistance and rotor flux linkage amplitude will change with different operating conditions, and the parameter changes will directly affect the motor control. System efficiency and stability. For the electric vehicle drive motor, its speed and torque are constantly changing, and the electric vehicle has high requirements on the efficiency and stability of the drive system, so it is necessary to conduct an online permanent magnet synch...

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Problems solved by technology

This solution requires additional sensors, which increases cost and is not easy to implement

[0010] (3) Use other means to obtain a certain parameter value, such as measuring the winding temperature through a temperature sensor, and then obtain the resistance value at the current temperature according to the physical characteristics of the winding, which increases the cost

[0011] (4) By injecting high-frequency current into the winding, and then deriving the parameter value by measuring the system response, this scheme requires a large amount of calculation, the process is complicated, and the performance requirements of the controller are high.

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