Sensorless control for a three-phase PWM rectifier-inverter system with single-chip micro-controller

A three-phase PWM rectifier-inverter system for a PMSM drive with a single-chip micro-controller is presented. To reduce the cost of the system, the input/output currents and dc-link voltage are detected only using resistors. With the proposed sensorless control, neither an ac voltage/phase sensor nor a rotor speed/position sensor is needed in the system. All of the proposed control schemes can be realized by a single-chip micro-controller (SH7149, Renesas Tech.). The experimental results from a 5-kW prototype confirmed that the proposed system worked well.