AC current sensorless control of three-phase three-wire PWM rectifiers

In this paper, an AC current sensorless control scheme of three-phase PWM rectifier is proposed. A method for reconstructing the AC currents from the DC-link current and switching state is given. A method of modifying the switching state of PWM rectifier is given when the input currents cannot be reconstructed. The control system based on SVPWM includes two PI controllers which are used to regulate the AC currents and DC-link voltage. The proposed control scheme reduces the systempsilas cost and improves its reliability. The feasibility of this scheme has been confirmed through computer simulations.