OUTPUT CURRENT SENSING METHOD FOR SINGLE-PHASE GRID-CONNECTED PHOTOVOLATAIC INVERTERS

摘要

The present invention relates to an output current sensing method of a single-phase grid-connected photovoltaic inverter, which connects anodes of a lower diode to each other in an H-bridge single-phase grid-connected photovoltaic inverter, connects an emitter of a lower IGBT to each other, interposes shunt resistance for measuring a current therebetween, and connects an anode of diode to a ground of a micro controller which is a negative pole of a direct current terminal capacitor, thereby allowing an inverter output current can continuously flow through the shunt resistance. Also, the output current sensing method of a single-phase grid-connected photovoltaic inverter can transmit the inverter output current to an analog to digital converter embedded in the micro controller only through a simple analog voltage amplifying circuit without insulating voltage of both ends of the shunt resistance. Therefore, costs can be reduced without decreasing performance.