Research And Implementation On Single Phase And Single Stage Of Grid-connected Micro-inverter

Due to the increasing worse of global energy shortage and environmental pollution problems,photovoltaic power generation has become a new industry in the world which has been paid muchattention because of its advantages such as clean, convenience, efficiency and security. Among thephotovoltaic power generation, the modular micro-inverter component which is suitable fordistributed power generation becomes a hot spot in domestic and foreign research. This topic studieson the topology and control scheme of the single phase and single stage of Grid-connected microInverter.First of all, in this paper, an overall scheme for the single phase and single stage ofGrid-connected micro-Inverter is designed. Micro-Inverter uses the active clamping staggered parallelflyback converter with power frequency steering bridge circuit as the main topology; Using anentirely Digital Control strategy to achieve the closed loop control of the whole system, and thecontrol unit is based on an high-performance digital signal controller (Digital Signal Control)MC56F8257launched by freescale.Secondly, a detailed hardware design for the single phase and single stage of Grid-connectedmicro Inverter is carried out..Through the theoretical analysis, calculation and the device parametercalibration,a reliable, safe and efficient hardware circuit is built which includes main power circuit,single chip microcomputer control circuit, analog signal sampling conditioning circuit and protectioncircuit.According to the design above, a detailed design for full digital control scheme is designed.Compared with TI, FPGA platform, freescale microcontroller platform has more advantage to designa set of perfect function of full digital control scheme. At the same time, the saber software is used tocompare the analog control simulation and digital control simulation verifies the feasibility andapplicability of fully digital control scheme.At last,a single phrase and single stage of Grid-connected micro-inveter prototype was made. Allthe testing results indicate that this inverter has great dynamic and static performance which meetneeds.