High-Frequency Voltage Injection Sensorless Control of Single-Shunt IPMSM Drives Using Simple Voltage Modification in Carrier-Based PWM

To reduce the number of sensors in interior permanent magnet synchronous motor (IPMSM) drive systems, position-sensorless vector control can be combined with single-shunt current reconstruction using a single DC-link shunt resistor. However, applying high-frequency (HF) voltage injection to a single-shunt drive system (SDS) at zero and low speeds causes current reconstruction errors and voltage distortion, thereby degrading the rotor position estimation performance. This paper analyzes these errors and proposes carrier-based voltage vector modification methods for both pulsating voltage injection (PVI) and rotating voltage injection (RVI). Unlike conventional methods requiring multiple pulse-width modulation (PWM) periods and analog-to-digital converter samplings within one control period, the proposed methods retain a conventional carrier-based PWM structure with one control period per PWM period. The voltage vectors in the measurement and compensation intervals are separated and positioned to reflect the current variation induced by the injected HF voltage while satisfying the current reconstruction conditions. Consequently, current reconstruction errors and voltage distortion are reduced without motor parameter-based prediction. The proposed methods are validated through simulations and experiments.