Inductance identification method based on current ripples

Abstract

The invention discloses an inductance identification method based on current ripples, and belongs to the field of online parameter identification of a permanent magnet synchronous motor. According to an identification technology provided by the invention, through the cooperation of three continuous control periods in a digital controller, the sampling of current ripples of a permanent magnet synchronous motor control system, the processing of a current ripple sampling result and the on-line identification of inductance by using the current ripples are completed. According to the identification technology provided by the invention, the accuracy of the current ripple sampling is improved by utilizing multiple continuous sampling and least square fitting, and the current ripple information is utilized through a simplified identification model. Compared with the prior art, the technology provided by the invention does not need to inject high-frequency voltage or current signals into the motor, so that the current distortion and torque fluctuation of the permanent magnet synchronous motor control system are reduced, and the motor loss and the rotor vibration are reduced.

Description

technical field [0001] The invention relates to the field of online parameter identification of permanent magnet synchronous motors, in particular to an inductance identification method based on current ripple. Background technique [0002] In many control algorithms of permanent magnet synchronous motors, such as various current control algorithms, maximum torque current ratio control algorithms, field weakening control algorithms, position sensorless control algorithms, etc., the inductance value of the dq synchronous coordinate system (L d , L q ) all play an important role. In order to ensure the performance of these control algorithms, online parameter identification techniques are used to obtain accurate L in real time d , L q become particularly critical. [0003] The existing online identification technology of permanent magnet synchronous motor parameters all use "dq-axis discrete electromagnetic equation with control period as discrete period" as the identifica...

AI Technical Summary

Problems solved by technology

Using this identification model causes the existing identification technology to have the following problems: since there are four unknown parameters in the two equations of the d-axis and the q-axis (d-axis inductance L d , q-axis inductance L q , resistance R, permanent magnet flux linkage ψ f ), so when performing parameter identification, you will encounter the problem that the identification model is not rank-satisfactory

In severe cases, it may even destabilize the permanent magnet synchronous motor

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