针对市面普遍的UPS光伏离网逆变器切换速度较慢的问题,提出一种用于UPS光伏离网逆变器中整流和逆变两个不同模式的快速切换方法,分析双向变换器的拓扑结构及其工作原理.双向变换器硬件电路拓扑采用全桥4个开关管的拓扑结构,软件部分采用基于PI的改进算法以及精确的电网有效值计算算法进行闭环控制,实现逆变整流不同模式之间的自动切换,达到UPS功能.将控制算法应用在实验室的硬件平台上,并且进行相应的测试实验,逆变整流波形均满足要求,模式切换时间小于同类UPS产品.如果要实现更大功率的输出以及更高系统的稳定性,可以进行离网逆变器的并联.%In order to solve the low switching speed of UPS photovoltaic off-grid inverter, a switching method for rectified mode and inverting mode in UPS PV inverter has been proposed. The topological structure and working principle of bidirectional inverter has been analyzed. The hardware of this bidirectional converter uses the full-bridge topology, the software uses improved closed-loop control method based on PI algorithm and algorithm for calculating the effective value of power grid. Thus the dual mode switching can be achieved. Lastly, the control algorithm has been already used on the hardware platform and corresponding tests have been opreated. Rusults show that the switching time is less than the similar UPS products and waves of rectified mode and inverting mode can both meet the requirements. If the higher output and system stability are required, the inverter can be carried out in a paralleled mode.
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