A Novel Daul Cuk Inverter With Wide Input Voltage

Inverter is a critical department of renewable energy which can realize grid-connected and run independently, so that it strives to develop in these years. Considering in the renewable energy system, such as in photovoltaic cells, fuel cells, and small wind turbine, the generating capacity is smaller, the output voltage is lower and the range of a transformation is wider. Therefore the traditional voltage bridge inverter is no longer meet the need. So a novel dual Cuk inverter with wide input voltage has been proposed in this paper. It can boost the input voltage or buck the input voltage. In addition, it also has a strong ability of anti-interference to input voltage, so it fully satisfies the need of small renewable energy system.On the basis of reading a large number of related foreign and national literatures, two improved Cuk converter are applied to input in series connection and output in parallel and merges the outputs inductor. At last a novel single stage transformerless structure of dual Cuk inverter is proposed in this paper. The detail of working principle and modulation has analyzed by theory and simulation. On the basis of research on the disorder waveform in open-loop, one cycle control, voltage closed loop control and current closed loop control were used in this circuit to make the output voltage in sinusoidal. Simulation and experimental results shows that the circuit can work in boost mode or buck mode, which can adapt to the large range of input voltage and has strong ability to reduce input voltage ripple to affect on the output, so it has extensive applications in small renewable energy system.On the basis of theory research and simulation results, a prototype is designed in this paper. The experimental results have proved that theoretical analysis and control strategy is correct and feasible.