Minimization of DC Reactor and Operation Characteristics of Direct-Power-Controlled Current-Source PWM Rectifier

This paper describes a direct-power-controlled current-source PWM rectifier, and presents operation characteristics by using a 2-kW experimental setup. The key of the proposed strategy is a direct selection of switching modes on the basis of a relay control technique of instantaneous active and reactive power, using an optimum switching table. The main feature of the direct power control is high-speed response of the power control; hence inductance of the DC reactor can be reduced. Feasibility of the strategy is verified through experimental tests, using the prototype. Experimental results demonstrate that the inductance of the DC reactor can be reduced down to 0.7 mH in the prototype, achieving the 92.5-% maximum efficiency, 99.9-% maximum total input power factor, and 3.1-% total harmonic distortion of the input current. Furthermore, operation characteristics are examined under unbalanced power source condition