An Overmodulation Method for PWM-Inverter-Fed IPMSM Drive With Single Current Sensor

In order to lower the cost and expand the working range of pulsewidth modulation (PWM)-inverter-fed interior permanent magnet synchronous motor drives, the control methods under the overmodulation mode with only a dc-link current sensor are investigated. The space vector modulation of the PWM inverter is analyzed in detail, and an adjustment scheme for the reference voltage vectors is developed to fulfill the requirements by phase current reconstruction under overmodulation. Furthermore, in order to simplify the control process and reduce the control errors, a specified overmodulation method based on the superposition principle is proposed for the PWM inverter with phase current reconstruction, which overcomes the shortcoming of the PWM adjustment scheme. Experimental results demonstrate the feasibility and the effectiveness of the proposed control method, which realizes the single current sensor overmodulation control with maximum voltage transfer ratio.