A new topology of hybrid synchronous machine

Permanent-magnet synchronous machines are able to operate over a wide range of speeds at constant power through the use of control laws allowing for f lux weakening. Generally, this is performed by applying a strong demagnetiz ing current in the d axis, yet such an approach involves the risk of irreve rsible magnet demagnetization and, consequently, a reduction in machine per formance. This paper presents a novel structure for a hybrid synchronous ma chine. Our solution provides good flux weakening without introducing the ri sk of magnet demagnetization. In order to explain the structure's operating principle, we apply a model with a single elementary design; electromotive force measurements will then be presented to demonstrate the possibilities of flux weakening, along with a series of simulations to show the contribu tion of hybrid excitation.