Research Of A New Standalone Inverter

With the development of economic and increasement of society requirement, the application of the standalone inverter is also increased quickly. Because standalone inverters are often supplied by 12VDC, even though the output power is medium, the input current of the standalone inverter is very big. And the switching consuming of power with inverter is also very lager. So efficiency of inverter is low. And for the use of kinds of equipments, the characteristic of inverter's output voltage must be very good. So, the technology of soft switching and System control will be the main study points in the paper. The four main researches are listed as following:Firstly, A topology structure with variable middle dc bus voltage is proposed for the standalone inverter application with high current and low voltage input. The front end is a LCL resonant soft switch push-pull DC-DC converter with fixed duty cycle control, followed by a cascaded full-bridge DC-AC converter with single-pole regulation. Secondly, The theory and design of the LCL resonant push-pull DC-DC converter is elaborated. Simulated experiment shows that LCL resonant push-pull DC-DC converter can realize zero voltage soft switching.Thirdly, A controller with disturbance cancelling for the DC-AC converter is proposed. Simulated experiment shows that the control method for the DC-AC converter is effective.Lastly, An industry prototype with 220VAC output and 1kw load is designed and produced. Tested experiment for industry prototype shows that LCL resonant push-pull DC-DC converter can realize zero voltage soft switching and the control method for the DC-AC converter is effective. Theoretical analysis is correct.