Multimode Carrier-Based PWM Strategy of Open-End Winding PMSM With Isolated DC Sources

A multimode carrier-based PWM strategy for open-end winding permanent-magnet synchronous motor (OW-PMSM) with isolated dc sources is proposed in this article. For the proposed strategy, the independent reference voltages of both the two inverters are obtained by decomposing the reference voltage output from the controller. Then, multiple modulation modes are established by different combinations of continuous PWM, discontinuous PWM and duty-cycle modulation for dual-inverter. As a result, the switching times of dual-inverter in each carrier period can be varied from 6 to 2. For the proposed strategy, the reference voltage is always synthesized by the nearest switching states. Thus, the output waveform quality for dual-inverter of the proposed strategy is better than that of the traditional modulation strategies. The feasibility and effectiveness of the proposed multimode modulation strategy is experimentally validated using a 4.3-kW OW-PMSM prototype.