Abstract :
Photovoltaic power systems need an actuating element for the adaption of the generator to the back-up battery or the DC link. Further, especially for these systems, high efficiency is desired. The DC/DC power converter with a two-switch structure improves efficiency and has an integrated power supply for the controlling unit, the data acquisition and the basic current for the main transistor. By switching off the main transistor of the converter, the current commutates to the auxiliary transistor and the integrated power supply is loaded. If its voltage is high enough, the auxiliary transistor switches off the current. The converter works on the effect that the auxiliary transistor (MOSFET) operates much faster than the main transistor (bipolar). For the dimensioning of the reactor, a new method, the so-called core distinctive number method, is used. The measurements show that the efficiency, especially in the range less than 1/3 of the maximum power, is better than for usual power converters
Keywords :
bipolar transistors; insulated gate field effect transistors; photovoltaic power systems; power convertors; power transistors; DC link; DC/DC power converter; MOSFET; PV power systems; auxiliary transistor; back-up battery; bipolar transistors; core distinctive number method; efficiency; generator; main transistor; power supply; power transistors; two-switch structure;
