Parallel DC-to-AC power inverter system with current sharing technique and method thereof

摘要

A parallel DC-to-AC power inverter system is provided. The parallel DC-to-AC power inverter system has a first DC-to-AC power inverter electrically connected in parallel with a second DC-to-AC power inverter, and each of the DC-to-AC power inverters includes an input port, an output port, a switching circuit electrically connected between the input port and the output port responsive to inverter control signals to convert a DC voltage at the input port to a first AC output voltage, an inductor-capacitor filter electrically connected to the switching circuit for filtering the first AC output voltage to an AC output voltage at output port, and a controller module for detecting an inductor current at the inductor-capacitor filter to generate an AC inductor current signal, for detecting the AC output voltage at the output terminals and transforming the AC output voltage to generate a first AC reference current signal, for detecting a load current at output port to generate an AC load current signal, for generating a second AC reference current signal by adding the first AC reference current signal to the AC load current signal, for performing a numerical operation of the second AC reference current signal of the first DC-to-AC power inverter and the second AC reference current signal of the second DC-to-AC power inverter to generate an AC reference current signal, and for generating the inverter control signals responsive to the AC reference current signal and the AC inductor current signal by sensing the inductor current at the inductor-capacitor filter. The related methods are also discussed.