POWER SUPPLY CIRCUIT AND PHOTOVOLTAIC POWER GENERATION SYSTEM COMPRISING SAME

A power supply circuit and a photovoltaic power generation system comprising same. The power supply circuit utilizes the condition that a voltage output by discharge of a capacitor is a direct-current voltage which decreases with time, a CCFL conversion circuit is connected behind the capacitor, the CCFL conversion circuit converts the input direct-current voltage which decreases which time into a sinusoidal alternating-current for output. Since the CCFL conversion circuit operates in an open-loop mode, a peak-to-peak value of the sinusoidal alternating-current output by the CCFL conversion circuit is in direct proportion to an operating voltage of the CCFL conversion circuit, the voltage decreases with time, that is, the peak-to-peak valve of the sinusoidal alternating-current output by the CCFL conversion circuit decreases with time, thus, an effective value of the sinusoidal alternating-current decreases with time, and an attenuated sinusoidal alternating-current voltage is obtained.