Field‐weakening in high‐performance PMSM drives

The comparative analysis of field‐weakening (FW) in vector controlled and DTC permanent magnet synchronous motor drives is performed. The results of simulations and a comprehensive set of experiments are also given. The possibility of unstable operation in the high‐speed region using DTC is emphasised. The present paper also highlights some important differences between DTC and vector drives in FW, such as quickness of torque response, torque/flux/current ripple content and implementation aspects. For this purpose two types of DTC drives are implemented, a classical DTC and also a DTC scheme with torque ripple reduction.