Simulation Research On Inverters Working In Parallel

Parallel inverters can expand capacity and realize redundancy in power supply system,so they are now considered as one of the most important part in the field of inverter technology. The parallel inverters can expand the capacity so that they greatly improve the power system's flexibility and thus the system's volume and weight are remarkably reduced. The current stress of the power switch is considerably lessened which means higher reliability, lower cost and higher power density. Because of the redundancy, the parallel system can improve the reliability furthermore.Based on the research of parallel inverters technology development ,author made these discussion list below1 First this text carries on setting up the mold to the main electric circuit structure and the control electric circuits of single phase inverter ,analyzing the mothodses to make sure the waves filter parameters and the controller parameters ,these parameters calculation method will provide the theories to the simulation.2 The next in order this text is detailed to analyse the principle and characteristics of parallel inverters, point out the produce reason of circle current and put forward several control methodses.3 Analyze the structure of double-loops control inverters which using one adjuster, current-sharing principle and the influence that the system parameter put on the circle current are put forward also. The parallel inverters point out in this text use PI adjuster for outer loop controller,and its output is the basis current of all inner loops.Inner loops adopt inductance current feedback mode ,this control mode has simple structure and small switch frequence .4 Simutate the double-loops control parallel inverters which using one adjuster with saber soft from several aspect such as hardware parameters,control parameters and dynamic capability .Because inductance current of all parallel inverters follow one basic reference current ,the system can avoid circle current which produced by basic difference ,then the waves filter parameters and current feedback parameters become the main factors of circle current.