Parallel Time-sharing Buck DC Chopper Type Single-stage Multi-input Integrated Power Generation System

With the decrease of fossil energy reserves and the aggravation of environmental pollution,trenewable energy has been paid more attention.New energy sources such as solar and wind energy are often used for power generation in the power system due to their clean,pollution-free,abundant reserves,and low prices.However,a single new energy supply has defects such as instability,discontinuity,and changes in temperature between day and night and climatic conditions.In order to ensure the quality of power supply and improve the stability of the power system,it is necessary to adopt a distributed power generation system that combines multiple new energy sources.This article discusses the development and status of the two-stage single-input DC converter-type distributed power generation system(PGS)and the two-stage multiple-input DC converter-type distributed PGS.On this basis,a parallel time-sharing power supply Buck type single-stage multi-input integrated PGS with multiple new energy combined power supply is proposed.The circuit topology,control strategy and working principle of the integrated(PGS)are analyzed,and the key circuit parameters are deduced.On this basis,the simulation analysis,prototype design and experiment of the system are completed.The proposed integrated PGS is composed of a parallel time-sharing power supply Buck type single-stage multi-input high frequency inverter and a battery charge and discharge converter connected in parallel on the AC output side.Among them,the singlestage multi-input high-frequency inverter consists of multiple common ground input filter capacitors,parallel time-sharing selector switches,combined isolation bidirectional Buck DC choppers,active clamp branches,and output filters.The battery charge-discharge converter is composed of an input filter circuit,a high-frequency inverter bridge,a highfrequency transformer,a cycle converter,and an output filter.The proposed maximum power output energy management control strategy suitable for the integrated PGS controls the direction and size of the power flow of the battery charge-discharge converter by comparing the sum of the power of the multiple input sources and the relative size of the load power,thereby realizing the output voltage Stable and smooth switching of different power supply modes and ensures the full utilization and priority utilization of a variety of new energy sources.In-depth study of the high-frequency switching process,input-output relationship,power switch turn-off voltage spike,output voltage DC bias and other key issues of the parallel time-sharing power supply Buck DC chopper-type single-stage integrated PGS,and calculated multiple channels The duty cycle expression of the input source draws the external characteristic curve of the single-stage multi-input high-frequency link inverter,and derives the design criteria for main circuit parameters such as input and output filters and high-frequency transformers.Using the proposed circuit topology and maximum power output energy management control strategy,PSIM simulation experiments and prototype experiments were performed on the 3k VA integrated PGS.The experimental results show that the proposed PGS has a simple circuit structure and easy to implement modules.High performance such as integration and integration,small weight and volume,good output waveform quality,electrical isolation of multiple input sources-output loads-battery,and smooth switching of multiple power supply modes.It has broad application prospects in a variety of new energy joint power supply occasions such as integrated wind and solar lighting,micro-grid,new energy trams.