Extended State Space Model of a Permanent Magnet Synchronous Machine as Part of a Stator Sided Resonant Inverter

The energy conversion of pulse width-based DC-AC-converters tends to cause significant electromagnetic disturbances. Electrical machines may be affected negatively by distressed isolations between the stator windings and shaft-currents which may cause damage to the bearings. In this contribution a modified load sided resonant converter is presented which is operated under fundamental frequency switching conditions to operate a surface mounted permanent magnet synchronous machine. The three-phase resonant tank consists of capacitors and the stator-sided stray inductances. It is modeled in time domain in order to evaluate the functional principle of the machine as part of the resonant tank. First, the topology and the concept of the resonant inverter is presented. Second, a novel state space model is derived and the selected brushless DC motor commutation and control strategy is presented. Third, the model is verified by a comparison with an experimental test setup. The work is closed by a discussion of the achieved results and an outlook on future work.