Inverter for converting direct current power into alternating current power and direct current bus voltage regulating method thereof and application using the same

An inverter, comprising:

• a resonant conversion circuit, receiving a direct current (DC) input voltage, and converting the DC input voltage into a DC bus voltage;
• an inverting circuit, coupled to the resonant conversion circuit, and configured to convert the DC bus voltage into an alternating current (AC) output voltage;
• a first control circuit, configured to control operations of the resonant conversion circuit, wherein the first control circuit calculates a best working voltage of the resonant conversion circuit based on the DC input voltage and a resonant frequency of the resonant conversion circuit;
• and
• a second control circuit, configured to control operations of the inverting circuit, wherein the second control circuit receives the best working voltage calculated by the first control circuit, and controls the inverting circuit to regulate the DC bus voltage accordingly,
• the second control circuit detects a magnitude of the AC output voltage, and calculates a normal working voltage required for maintaining a normal operation of the inverting circuit accordingly, and
• one of the first control circuit and the second control circuit compares the best working voltage and the normal working voltage, and the second control circuit controls the inverting circuit to regulate the DC bus voltage to one of the best working voltage and the normal working voltage according to a comparison result.