Space-vector PWM for inverters with split-wound coupled inductors

This paper proposes a space-vector pulse width modulation (SVPWM) technique suitable for inverters with a coupled inductor output. The proposed approach is based on multi-level SVPWM and can offer superior performance when compared to other modulation techniques suitable for coupled inductor topologies. In particular the approach addresses issues related to common mode DC current balance in a three-limb inductor core and coupling between limbs in a three-limb core. The proposed approach provides a multi-level output voltage waveform while the total winding current distortion is significantly improved. This is achieved by appropriate choice of switching states such that effective low inductance modes are eliminated while generating half-wave symmetrical switching frequency voltage waveforms. The method presented is computationally simple and does not additional feedback signals when compared to conventional three-level SVPWM algorithms. The operation of the proposed drive structure is investigated by means of simulation results and verified by experimental results.