Buck-Boost Type Single-stage Multi-input Inverter With Multi-winding Simultaneous Power Suppl

Traditional methods of energy power generation can lead to a series of problems such as energy depletion and environmental deterioration,which is not conducive to the sustainable development of the world.Therefore,researchers around the world have put their attention to the emerging field of new energy power generation.Among them,new energy multi-input inverters can not only convert multiple new energy DC power into AC power required to load,but also overcome discontinuous and unstable defects of single new energy supply,causing researchers wide attention.In this paper,the circuit structure and working characteristics of the traditional two-stage multiinput inverter are discussed with topological examples.Aiming at its shortcomings such as low conversion efficiency,many power devices,low power density,and complicated control,a novel multi-winding time-sharing Buck-Boost single-stage multi-input inverter is proposed.Key technologies such as circuit topology,energy management control strategy,steady-state principle characteristics,and control loop parameters are deeply analyzed and studied.On these basis,the simulation analysis and device experiment of the proposed multi-input inverter is carried out,and important conclusions have been obtained.The circuit topology of the multi-winding time-sharing Buck-Boost type single-stage multiinput inverter is composed of input filter,tow multi-input single-output isolated bidirectional Buck-Boost choppers working for half a low-frequency cycle respectively,freewheeling switch,and a common output filter.Each The multi-input single-output isolated bidirectional Buck-Boost chopper is composed of a high-frequency inverter power switch,a multi-winding energy storage transformer,and a high-frequency rectifier power switch.The adopted master-slave power distribution energy management SPWM control strategy including input current feedback loop and the output voltage feedback loop can achieve full use of new energy while ensuring the stability of the output voltage,so that the two power supply modes of the inverter can change smoothly with the change of illumination and load conditions.In this paper,the working mode and high-frequency switching process of the multi-input inverter are deeply analyzed,the voltage gain expression and external characteristic curve of the multi-input inverter are deduced,and the influence of the internal resistance on the voltage gain is studied.In order to suppress the turn-off voltage spike of the power switch caused by the leakage inductance energy of the energy storage transformer,two different clamping circuit schemes are proposed and their working principles are analyzed.In addition,a small-signal model of the multiinput inverter is established.According to the characteristics of the control loop and combined with the dynamic response curve,the parameters of the voltage and current regulators are designed.Circuit parameters design guidelines such as energy storage transformers,filter capacitors,power switching voltage and current stress is studied.Using the proposed topologies and energy management control policies,The experimental device of 1k VA 96VDC/220V50 Hz AC multi-winding time-sharing Buck-Boost single-stage multi-input inverter is designed and developed.PSIM simulation and device experiments confirmed the correctness and feasibility of the proposed multi-winding time-sharing Buck-Boost single-stage multi-input inverter,which provides a novel and effective single-level solution for multi-input source inverters.