Comparative Study of Voltage Source Inverter Nonlinearity Compensation using different Signal Information for Table look up in PMSM Drives

Abstract

The inverter nonlinearity compensation has been studied by the researchers widely, however, due to the poor polarity detection ability of the discrete control system and unavoidable noises from current feedback, unideal compensation happens when the motor speed is low and the load is small. In order to tackle with this problem. This paper presents an inverter nonlinearity compensation method in permanent magnet synchronous motor (PMSM) drives. The overall process is achieved by voltage signal injection, the only requirements are stator resistance and the maximum current of a given motor. The corresponding voltage errors are saved in look up table (LUT) and being used together with field-oriented control (FOC). In addition, a comparative study when using phase current feedback, phase current reference and phase voltage reference for compensation voltages look-up in the already established LUT is conducted. A 750-W voltage-source inverter PMSM drive controlled by the FOC algorithm is used for experiment verification, the results show that the phase current reference is the most proper signal for compensation voltages look-up, especially around the current zero-crossing condition. The comparative study in this paper can be easily applied in the real industrial application with no hardware introduction and very little algorithm change.