| 摘要 |
PURPOSE:To allow optimal control of charge/discharge voltage by fully utilizing the power generated from solar cells while ensuring the reliability of a battery. CONSTITUTION:Power generated by solar cells 28 is fed to an inverter 15 during daytime and a maximum output power control circuit 20 controls a bidirectional converter 4 to generate maximum power from the solar cells 28. Excess power is returned back to a single phase commercial power supply 1 through the bidirectional converter 4. When the output power from the solar cells drops during daytime due to rainy or cloudy weather, power is fed from a battery 32 to the inverter 15 and deficiency of power is supplemented by the commercial power supply 1 through the bidirectional converter 4. In nighttime, the bidirectional converter 4 is controlled with reference to the voltage of a DC power supply 21 and power is fed to the inverter 15 from the commercial power supply 1. Furthermore, a charging current control circuit 22 controls the bidirectional converter 4 to charge the battery with an optimal voltage. |
