DC-to-AC power conversion system and method of operating the same

摘要

A DC-to-AC power conversion system is provided to convert a DC input voltage into an AC output voltage, which mainly includes a bridge switching circuit, an auxiliary switch circuit, and a control circuit. The bridge switching circuit has a first power switch, a second power switch, a third power switch, and a fourth power switch. The auxiliary switch circuit has a fifth power switch, a sixth power switch, a seventh power switch, and an eighth power switch. The control circuit produces a complementary switching signal pair to control the first and fourth power switches and the second and third power switches, respectively. In addition, the control circuit produces a complementary level signal pair to control the sixth and seventh power switches and the fifth and eighth power switches, respectively.

主权项

1. A DC-to-AC power conversion system converting a DC input voltage into an AC output voltage, the DC-to-AC power conversion system comprising:
an input capacitor set having a first capacitor and a second capacitor, and the first capacitor and the second capacitor connected to a neutral point and configured to receive the DC input voltage; a bridge switching circuit connected in parallel to the input capacitor set, and the bridge switching circuit having a first bridge arm and a second bridge arm connected in parallel to the first bridge arm; wherein the first bridge arm is composed of a first power switch and a second power switch connected in series to the first power switch, and the second bridge arm is composed of a third power switch and a fourth power switch connected in series to the third power switch; an auxiliary switch circuit connected between the neutral point and the bridge switching circuit, and the auxiliary switch circuit having a third bridge arm and a fourth bridge arm connected in parallel to the third bridge arm; wherein the third bridge arm is composed of a fifth power switch and a sixth power switch connected in series to the fifth power switch, and the fourth bridge arm is composed of a seventh power switch and an eighth power switch connected in series to the seventh power switch; a filter circuit having a first filter inductor, a second filter inductor, and a filter capacitor; wherein the filter capacitor is connected between the first filter inductor and the second filter inductor, the first filter inductor is connected to the first bridge arm and the third bridge arm, and the second filter inductor is connected to the second bridge arm and the fourth bridge arm; and a control circuit configured to produce a complementary switching signal pair and a complementary level signal pair; wherein the complementary switching signal pair is configured to control the first and fourth power switches and the second and third power switches, respectively; the complementary level signal pair is configured to control the sixth and seventh power switches and the fifth and eighth power switches, respectively; wherein the auxiliary switch circuit is configured to provide the energy-releasing loops of the first filter inductor and the second filter inductor to reduce leakage currents of the DC input voltage caused by parasitic capacitance voltages.