一种适用于变频器低电压穿越电源的三重Boost电路仿真及实验分析

Simulation and Experimental Analysis of a Triplex Boost Circuit for Frequency Converter Low Voltage Ride Through Power Source

电厂及各类工矿企业的辅机大量采用变频器,而此类变频器抵抗电压跌落能力差、不具备低电压穿越能力,易造成的机组停机故障,直接威胁电网安全。因此研制变频器低电压穿越电源(LVRT),在电网故障时支撑变频器运行,具有重要意义。针对该问题,采用经典的DC-DC升压电路,研制出了基于三相交错并联Boost直流变换电路的LVRT电源,仿真及现场实验均显示,三相Boost交错并联可以减小输入电流纹波和开关管应力,且三相电流具有很好的一致性,能有效的提高变频器的低电压穿越能力且具有良好的动静态输出特性。

At present,a lot of frequency converters are used in the auxiliary machineries of power plants and industrial enterprises,however,such inverters have poor ability on low voltage ride through（LVRT）easily resulting in power plants shutdown in succession,and threatening the power grid security.It is,therefore,important to develop LVRT to support the operation of frequency converters.A LVRT power source with three-phase interleaving parallel Boost DC conversion circuit is developed by using the classical DC-DC boost circuit.Digital simulation,prototype test and application approve that the proposed power source could decrease the input current ripple and the stress on switching tube,with good consistency of threephase current,which can effectively improve the low voltage ride through capability of the inverter with good dynamic and static output characteristic.