State Reference Computation for PMSM Implemented with Single-Precision Floating Point Datatype

摘要

Typically, electrical drives with permanent magnet synchronous machine (PMSM) require a separate reference current generation to map a torque request to optimal phase currents. However, many algorithms are based on simplifications and therefore do not lead to an operation with minimum losses and maximum torque. Others require the usage of double-precision algorithmics to obtain accurate results. This paper proposes an algorithm for reference current computation considering the maximum-torque-per-ampere and the maximum-torque-per-volt criterion, a potentially variable DC link voltage and resistive voltage drops. The algorithm is based on the steady-state PMSM equations. It is able to handle saliency and fluctuating motor parameters, e.g. due to magnetic saturation. It fulfills the requirements for a usage in a hard real-time application and in comparison to other approaches it works with single-precision floating point datatype and is therefore specially suited for cost-effective drives.