A feedback linearizing control scheme for a PWM converter-inverter having a very small DC-link capacitor

This paper addresses a control method of reducing the size of the de-link c apacitors of a converter-inverter system, The main idea is to utilize the i nverter operation status in the current control of the converter. Specifica lly, the information on the load power is incorporated in synthesizing the converter current control input so that a proper de voltage level Is mainta ined. We describe the dynamics of load current and apply feedback lineariza tion theory to obtain an input output linearized system. Theoretically, thi s central strategy is effective in regulating the de voltage level, even th ough the de-link capacitor is arbitrarily small and load varies abruptly. T he superior performance is demonstrated through simulation and experiment. An experiment was performed with a 9-kW pulsewidth modulation converter-vec tor inverter system having a 75-mu F de-link capacitor.