A method for multi-parameter identification of a permanent magnet synchronous motor without position sensor considering position error

Abstract

This invention provides a sensorless multi-parameter identification method for permanent magnet synchronous motors (PMSMs) that takes position errors into account. To address the estimation error problem caused by time-varying motor parameters due to changes in operating conditions and inverter nonlinearity, this invention utilizes a parameter identification method to compensate for and correct model parameter errors within the algorithm, thereby reducing speed and position estimation errors. Considering the coupling problem between position and parameter errors in sensorless control systems, this invention establishes an identification equation to suppress the influence of position errors and introduces a signal injection module to enhance the identification excitation of the control system. The data acquisition module obtains the operating data required for solving the identification equation under different direct-axis current conditions. An iterative calculation module based on the Levenberg-Marquardt method is used to solve for the parameter identification quantities. A parameter compensation module compensates and corrects the motor parameters, achieving correction of the parameters set within the algorithm and feedforward compensation for dq-axis voltage errors. The method of this invention can significantly improve the parameter robustness and estimation accuracy of sensorless motor control systems.

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