Research On Low Voltage Spikes Two-winding Coupled-inductors Impedance Source Inverters

Traditional coal,oil and other energy generation structure leads to energy shortage,global warming and many other problems,so decarbonized distributed renewable energy,such as solar photovoltaic,wind energy,hydro energy,bio-energy,gradually replace the traditional power generation structure.For solar photovoltaic power generation,as the output of photovoltaic panels are often volatile direct current,the majority of the existing engineering load is ac load,and the needs of the output voltage level is often higher than the raw output of photovoltaic panels,so we need the connection between the photovoltaic panels and ac load can be achieved on the high voltage gain of the inverter.Similarly,for other distributed renewable energy generation such as wind power generation,there is also a urgent need for high voltage gain inverters.However,due to the inherent defects of traditional inverters,output waveform distortion and limited voltage gain are common problems.Therefore,this paper intends to solve the problems existing in traditional inverters and conduct an in-depth study on optimized dual-winding coupled-inductors impedance source inverters,the specific contents of which are as fo llows:This paper analyzes the working principle of T-source inverter,the forming reason of dc-link voltage spikes,and the influence o f coupled-inductors leakage.For the T-source inverter,based on the dc-link voltage spikes absorption circuit,a low-voltage spike optimized T-source inverter is proposed,which can effectively reduces the dc-link voltage spikes and recovers the leakage energy.At the same time,this kind of optimized T-source inverter with low dc-link voltage spikes has higher efficiency.For optimized T source inverter with low voltage spikes input current is discontinuous problems,first put forward T-type efficient input continuous dual-winding coupled-inductors impedance source inverter which has the characteristics of continuous input current,higher voltage boost capacity,starting current shock suppression,leakage energy recovery and so on,and still has the function of dc-link voltage spikes suppression.On this basis,by changing the structure of T-type dual-winding coupled-inductors in the topology,a family of low dc-link voltage spikes optimized dual-winding coupled-inductors impedance source inverters can be further obtained,which can effectively expand the application range of optimized dual-winding coupled-inductors impedance source inverter.A precise loss model is established for the dual-winding coupled-inductors impedance source inverter.The power loss of each component in the improved inverter is compared and analyzed.Moreover,under the rated power of 200 W,the specific power losses of the improved topology are calculated respectively.It is theoretically proved that the proposed topology can effectiv ely improve the system efficiency.Finally,the experimental platform is designed and built,and the proposed optimized T-source inverter with low dc-link voltage spikes and the optimized input continuous dual-winding coupled-inductors impedance source inverter with low dc-link voltage spikes are tested and verified,proving the feasibility of the two new topologies.