三相降压/升压/升降压型多功能并网逆变电路

Three-phase Buck/Boost/Buck-Boost-type Multifunctional Grid-connected Inverter

逆变技术在新能源开发和利用领域充当着极其重要的地位,在此提出一种三相降压/升压/升降压型多功能逆变电路,并对该逆变电路3种工作模式下的换流状态和调制方式进行了分析。然后,根据三相电网电压瞬时值的关系及并网要求,讨论了该逆变电路在各个模式下控制器的设计,并就如何将占空比分配到各个开关管进行了分析。当逆变器工作在降压模式时,一个开关周期内有3个高频管;工作在升压或升降压模式时,有两个开关管工作在高频状态,其余开关管都处于低频开通或关闭状态,并给出了各工作模式下抑制高频管开通损耗的办法。最后,通过仿真及实验对该逆变电路的可行性和稳定性进行了验证。

The converter technology plays a crucial role in the utilization of alternative energy,a three-phase buck/boost/buck-boost-type multifunctional grid-connected inverter is presented,and the conduction states and modulation modes of the inverter for three-types are analyzed.According to the relationship of the grid and the requirements of grid-connection,the modulation method and controller are discussed.When the inverter works on buck mode,there are three switches work with a high frequency in a switching period,and during the operation of boost or buck-boost mode,there are two switches commutate with a high frequency,whereas the other switches are in low frequency switching state.The method of suppressing the opening loss of switches that work with high frequency in every inverter mode are given.Finally,the feasibility and stability of the inverter are verified by the simulation and experiment.