Self-commissioning compensation of inverter non-idealities for sensorless AC drives applications

High performance sensorless AC drives require the exact knowledge of the motor phase voltage in the whole speed range. The use of specific voltage sensors can be avoided if the reference voltage signals can be used instead of the actual (measured) phase voltages. Thus, an accurate compensation of most of inverter non-idealities is essential in modern sensorless control as well as in all applications that foresee flux-estimation. This paper presents a step towards the optimal inverter nonidealities compensation for high-performance sensorless drives application. The proposed start-up offline procedure does not require the exact power components parameters, and it can be readily implemented on existing hardware structure, without any additional external circuit. For validation purposes, the algorithm has been merged with a full-digital sensorless control of an induction motor drive, exploiting the computation facilities of the floating point DSP TMS320C31. Extensive experimental results and comparisons with existing techniques are given in the paper.