Patent ID: 8471409

Claim:
A power conversion circuit, comprising: a first receiving end electrically connected to a renewable power supply; a second receiving end for receiving a grid power; a load end for electrical connection with a load; a DC-DC converter having an input end electrically connected to the first receiving end to thereby convert output voltage of the renewable power supply into a stable direct current link voltage according to a duty cycle of a first modulation signal; a DC-AC inverter having an input end electrically connected to an output end of the DC-DC converter to thereby receive the direct current link voltage and convert the direct current link voltage into an alternating current link voltage according to a duty cycle of a second modulation signal; an output circuit electrically connected to an output end of the DC-AC inverter, the second receiving end, and the load end so as to supply one of the alternating current link voltage and the grid power to the load; a feedback circuit electrically connected to the first receiving end, the output end of the DC-DC converter, the output end of the DC-AC inverter, and the second receiving end so as to feed back a first feedback signal corresponding to the output voltage of the renewable power supply, a second feedback signal corresponding to an output current of the renewable power supply, a third feedback signal corresponding to the direct current link voltage of the DC-DC converter, a fourth feedback signal corresponding to an output current of the DC-AC inverter, and a fifth feedback signal corresponding to the output voltage of the grid power; a detecting circuit electrically connected to the feedback circuit for receiving the fifth feedback signal and performing computation according to the fifth feedback signal so as to obtain an angular position of the grid power; a control module electrically connected to the feedback circuit and the detecting circuit for converting expression of the fourth feedback signal and the fifth feedback signal in terms of two-axis stator coordinates into expression of the fourth feedback signal and the fifth feedback signal in terms of rotor coordinates according to the angular position, outputting a first control signal according to the first feedback signal, the second feedback signal, and the third feedback signal, and outputting a second control signal according to the first feedback signal, the second feedback signal, the third feedback signal, and the fourth feedback signal and the fifth feedback signal which are expressed in terms of the rotor coordinates; and a pulse width modulation regulator electrically connected to the control module for outputting the first modulation signal according to the first control signal and outputting the second modulation signal according to the second control signal.