Research On Topology And Control Strategy Of Photovoltaic Grid-connected Micro-inverter

A single PV module grid-connected system is an effective way to solve themismatch and hot spots problems caused by the different characteristics andshadows existing in the PV array of traditional PV module grid-connected systems.As an inverter used in a single PV module grid-connected system, micro-inverterhas a proper power demand matching ability with a single PV module and highpower conversion efficiency.Several common topologies of inverter are analyzed and compared in this paper.Topology of boost-half-bridge micro-inverter with high frequency, which is easy tocontrol, is selected as the research object.The working principle of boost-half-bridge micro-inverter is analyzed andduring which it is found to achieve ZVS and thus reduce the switching loss of thesystem. The control strategy is researched according to the topology, The MPPTcontrol, grid-connected current control and anti-island strategy is designed and theaccording control strategy is acquired.The main circuit, detection circuit and auxiliary circuit of the micro-inverterare designed in this paper. The topology and control strategy of boost-half-bridgemicro-inverter is simulated through the simulink of Matlab and the simulationresults verify the feasibility of the system.