基于解耦控制的多模块逆变器并联系统直流环流抑制策略  

The DC Circulation Current Control Strategy Based on Decoupled Control Scheme in the Multi-module Paralleled Inverter System

作　　者：何国锋[1] 徐德鸿[1] 

机构地区：[1]浙江大学电气工程学院,浙江省杭州市310027

出　　处：《中国电机工程学报》2012年第18期43-51,176,共9页Proceedings of the CSEE

基　　金：国家自然科学基金项目(50877072)~~

摘　　要：提出一种基于解耦控制的控制策略以抑制多模块不间断电源(uninterrupted power supply,UPS)并联系统的直流环流。在基于平均功率控制的并联系统中,对每个并联逆变模块设置一个独立的电压直流分量抑制电路,通过校正逆变基准值控制每台逆变器输出电压直流分量为零,从而达到控制并联系统的直流环流为零。由于各个模块独立调节,因此实现了各个并联模块之间的直流环流控制上的解耦。3台15 kVA并联UPS系统实验结果表明,该文所提控制策略能可靠、有效地抑制并联系统的直流环流。This paper proposes a novel Control strategy based on decoupled control scheme to eliminate DC circulation current in the Multi-module paralleled uninterrupted power supply（UPS） system.On the basis of the original paralleled system for load sharing by active and reactive power control,a separate control circuit is added in each paralleled inverter module to eliminate the DC component of output voltage.The voltage between the middle point of inverter half bridge and the middle point of the DC capacitors is measured to accurately detect DC voltage offset of inverter.The difference between the feedback DC voltage and the reference DC component is regulated by proportional-integral controller to obtain the compensating DC voltage component.Therefore the DC voltage component of each inverter output voltage can be regulated to zero by adding the feedback DC voltage component to inverter output voltage reference.This method is based on the idea that DC voltage offset of each inverter is decoupled.In this way,the DC circulation current of paralleled UPS system Can be eliminated by regulating each parallel inverter module＇ DC voltage component to zero.Because each module only regulates its own DC voltage component,the DC circulation current control is decoupled.The experiment in three paralleled 15 kVA three-phase UPS system proves feasibility and reliability of the control strategy.

关 键 词：不间断电源 解耦控制 多模块并联 直流环流 有功功率、无功功率控制 

分 类 号：TM464[电气工程—电器]