| With the accelerating process of economic globalization and the rapid development ofindustrial economy, energy demand is growing and energy crisis and environmentalpollution are becoming more and more serious. Seeking new energy sources has become thecurrent urgent subject in humans. In all of the renewable energy sources, solar energy is agreat potential new energy, especially for the focus of application research in photovoltaicgrid-connected power generation. As one of the important parts in grid-connected powergenerator system, the grid-connected inverter’s performance directly influences the energyefficiency.Based on the detailed discussion to the research status and development of thegrid-connected inverter and the analysis to the characteristics of photovoltaic cells andmaximum power point tracking(MPPT) control methods, the engineering model ofphotovoltaic cells is built and the push-pull forward Buck mode grid-connected inverterwith high frequency link is researched in this paper, which is specially fit for low-voltageand high-current input occasion. The inverter, which is controlled by SPWM transientcurrent control strategy, is composed of the unidirectional push-pull forward Buck modeDC/DC converter and the polarity reversal inverter.In this paper, circuit topologies, transient current control strategy, the characteristic ofsteady principle and design criteria for the key circuit parameters are deeply investigated,and furthermore, the transient current control strategy with MPPT is also proposed.The analysis and simulation results of1kVA40~60VDC/220V50HzAC the push-pullforward Buck mode grid-connected inverter with high frequency link have shown that theinverter has the advantages such as simple topology, high frequency electrical isolation,unidirectional power flow, DC/DC stage controlled in SPWM, the power switches ofpolarity reversal inverter having low voltage stress and ZVZCS etc. The correction andfeasibility of this inverter are fully verified by the principle test. |
PDF Full Text Request