Development Of 5KW Single-phase Household String Inverter Based On H6 Bridge Topology

As the world’s population continues to grow,the pressure on energy is also increasing,which forces people to continue to find and develop new types of sustainable clean energy.Solar energy is the most promising energy source of simple,convenient and sustainable use among all new energy sources.The use of solar energy for photovoltaic power generation is a research hotspot in countries around the world.The core part of the photovoltaic power generation system is an inverter.This paper develops a residential inverter and develops a 5KW single-phase residential string inverter based on the H6 bridge topology.The specific contents include the following aspects:1.Introduce the current photovoltaic power generation system,focus on the advantages of photovoltaic power generation,and analyze the prospects of the photovoltaic market.2.Give the design scheme of the inverter main circuit in the photovoltaic power generation system.In order to improve the working efficiency of the inverter,the two-way boosting method is adopted;the inverter part adopts the H6 bridge topology to overcome the shortcomings of the traditional H4 bridge that cannot suppress the leakage current.According to the product standard,the parameters and models of key components are given.3.Design the control circuit of the inverter.The control circuit includes an input voltage and current sampling circuit,an output voltage and current sampling circuit,a zero-crossing detection circuit,a switching tube drive and protection circuit,a leakage current detection circuit,and a switching power supply circuit.4.Explain the software design of the control system.The software design of the control system is divided into two parts:the main program and the interrupt program.The main program is responsible for the initialization of the system and detects the flag bits of each interrupt subroutine;the interrupt program implements inverter data sampling and processing,algorithm implementation,output pulse width modulation and Inverter protection.5.Developed a 5KW single-phase household string inverter prototype,and tested it on the actual circuit.The test results showed that the inverter’s inverter efficiency reached 97.74%and the total harmonics were less than 5%,which met the product design standards.,The designed inverter is now on the market.