Analysis and Design of LCC Converter Controlled by a Switch-Controlled-Capacitor

This paper presents a LCC-SCC resonant inverter suitable for high-frequency electric source, broadband ultrasonic transducer power. Traditional SPWM modulation strategy is unable to solve high-frequency modulated wave, and hard switching also causes large power loss. This novel topology utilize LCC resonant tank to achieve high-frequency inverter, and zero-voltage switching (ZVS) performance is obtained. Combined with a switch-controlled capacitor (SCC) and its control strategy, the voltage gain can be dynamically adjusted. Therefore, even in the case where the load and input voltage vary at different modulated frequency, the output voltage can be balanced and maintained at a constant value, and the total harmonic content (THD) is less than 5%. The correctness and feasibility of the proposed inverter and control strategy are verified by simulation.