供电电网对电压源型变频器运行的影响研究  

Research on the Influence of Power Grid on the Operation of Voltage Source Inverter

作　　者：王璐琤 何栋林 张风江 

机构地区：[1]上海辛格林纳新时达电机有限公司,上海201800

出　　处：《大功率变流技术》2017年第6期61-66,共6页HIGH POWER CONVERTER TECHNOLOGY

摘　　要：针对变频器频繁出现三相输入电流不平衡、内部器件因为过压或过流而损坏的现象,文章从低频和功率角度出发,分析了电网不平衡度、线路阻抗及多路负载对电压源型变频器工作特性影响的机理,指出电网负序分量会引起输入电流不平衡,导致低频谐波电流增大,严重时会致使器件烧毁;线路阻抗影响系统串并联谐振频率、变频器输入电压及其输入感性电流比例,是引起系统谐振、导致器件过压击穿的重要因素之一;多台变频器同时工作时能起到抑制谐波电流的作用,文中通过理论计算、仿真和实测数据证明了该观点的正确性。文中还提出了一些能帮助变频器的设计者和使用者规避应用风险的措施,提高变频器工作的稳定性。Three-phase input current unbalance is often happened in inverters, which causes devices damaged by overvoltage or over-current. Influences of grid unbalance, line impedance and multi-load on voltage source inverter and their mechanisms were analyzed from the point view of low frequency and power. It presented that three-phase input current unbalance is caused by negative sequence components of grid voltage and makes low frequency harmonic current increased and even devices damaged in inverter. The fact that line impedance affects serial or parallel frequency, input voltage and proportion of input inductive current was pointed out, which is one of the important factors causing the system resonant and devices breakdown by overvoltage. It also proposed that multi-inverter operation would suppress harmonic input currents and the results of theoretical calculation, simulation and practical test showed the correctness of the view point. Moreover, it presented some relative measures, and this can help designers and users to avoid application risks of inverters and improve the stability of the machines.

关 键 词：电网不平衡度 线路阻抗 无功补偿 并联谐振 零序分量 

分 类 号：TN773[电子电信—电路与系统]