|Budget Amount *help
¥3,600,000 (Direct Cost: ¥3,600,000)
Fiscal Year 1999: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1998: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1997: ¥2,600,000 (Direct Cost: ¥2,600,000)
Newly developed photovoltaic utility interactive inverter is 3kW rated power. In the inverter, there is a transformer integrated T-LCL type immittance converter newly designed in insulated high frequency link which worked at 19kHz. At 60Hz, a sinusoidal current of 3% distortion factor is obtained without the feed back control, and is little affected by the amplitude and the wave form distortion of the utility voltage. Waveform and amplitude of the sinusoidal current don't change, when the utility voltage changes stepwise, and the transient oscillation disappears in 0.1 millisecond. The overall efficiency of the photovoltaic interactive inverter is over 90%.
Basic characteristics such as frequency characteristics, voltage-current transfer characteristics, efficiency characteristics were clarified on resonant immittance converter of 5 types. The immittance converter of all types has maximum efficiency when the load impedance is equal to the characteristic impedance. The maximum efficiency is 98%, if the Q of the reactor is 100 in the LCL type immittance converter. In experiments, the 98.6% maximum efficiency has been obtained using the LCL type immittance converter, and 99.4% maximum efficiency has been obtained using the hybrid type immittance converter. It became clear that the deviation of the resonant frequency and source frequency could be permitted ± 5%.
The power receiving end in the carrier supplied power by a Non-Contact Energy Transfer System is one of the useful application of the immittance converter. In the system, the high frequency constant current at the receiving end is converted into a constant voltage by the immittance converter, then it is rectified, and a DC constant voltage is obtained. The rectifying technology of the output of the immittance converter is common to the photovoltaic utility interactive inverter.