Patent ID: 8837177

Claim:
An electric generating system using a solar cell comprising: a converter for converting an output voltage generated from the solar cell into a DC voltage in a pulse shape; an inverter for converting the DC voltage in the pulse shape into an AC voltage and applying the AC voltage to a power system; and a control device for determining whether an erroneous operation of the electric generating system using the solar cell is generated or not based on an output voltage of the solar cell, an output current of the solar cell and a voltage of the power system and for controlling in such a way that at least one inverter switching device among a plurality of inverter switching devices performs a switching at a frequency higher than a frequency during a normal operation at an interval where the erroneous operation is generated, wherein the control device includes: a converter control unit for determining whether an erroneous operation is generated in the electric generating system using the solar cell and generating a compensation signal for compensating an inverter control signal to control the inverter switching devices according to the generation result of the erroneous operation, and an inverter control unit for controlling in such a way that at least one inverter switching device among the plurality of inverter switching devices performs a switching at a frequency higher than a frequency during a normal operation at an interval where the erroneous operation is generated by using the compensation signal and a commercial frequency signal of the power system, wherein the converter control unit includes: a comparator for comparing a first reference signal with a current command value to control a converter switching device and outputting a converter control signal as a comparison result, and a compensator for calculating a threshold value by using an output voltage of the solar cell, conduction rate information of the converter switching device and the DC voltage, determining whether the erroneous operation is generated or not by using a result obtained by comparing the calculated threshold value with the current command value and outputting by varying the compensation signal according to the erroneous operation generation state.