| 摘要 |
PURPOSE:To always take out a maximum power from a DC power source by satisfactorily performing the maximum power point tracking control regardless of the variance in voltage-current characteristic of the DC power source like a solar battery. CONSTITUTION:A CPU 48 outputs the waveform pattern read out from a ROM 49 to a D/A converter 51 to obtain a reference sine wave signal S11 and switches an FET bridge 36 through a PWM modulation circuit 43 and a gate drive circuit 42 to convert the DC power from a solar battery 32 to an AC power. A detected inverter output current IOUT is converted to a digital value by an A/D converter 47 and stored in a RAM 50. The CPU 48 compares the preceding output current value and the present, output current value with each other to discriminate whether the output current IOUT is increased or not. The amplitude changing direction of the reference sine wave signal S11 is kept if it is increased, but this direction is inverted if it is reduced, and the amplitude of the reference sine wave signal S11 is changed in the determined direction by one stage to perform the maximum power point tracking control of the solar battery 32. |
