Power Capability of Hybrid Excited Synchronous Motors in Variable Speed Drives Applications

Power capability of synchronous machines, when operating in motoring mode, is discussed in this contribution. Maximum power limits and partial loads operations are both examined in the case of variable speed drives applications when the synchronous motors are driven with idealized inverters with limited volt-ampere ratings. This study is based on a per-unit d-q model normalized according to the base speed operation quantities. Different control strategies are thoroughly analyzed for different motors parameters. The use of per-unit quantities will help to draw some general conclusions regarding the effect of motors parameters on the drives performance. Since wound field (WF) excited and permanent magnet (PM) excited synchronous motors could be considered as particular cases of hybrid excited synchronous motors, the findings of this contribution would be applicable to all synchronous motors with a magnetic excitation source.