串联电压与并联电流补偿相协调的统一电能质量调节器控制策略研究

Control Strategy of Unified Power Quality Conditioner With Series Voltage and Parallel Current Compensation

随着大量分布式新能源接入配电网,越来越多电力电子设备接入使得输配电和负载终端的非线性负载增加,则会出现电压、电流波形畸变的电能质量问题。针对此种情况,统一电能质量调节器(unified power quality conditioner,UPQC)能综合解决电能质量问题,具备无功补偿、三相不平衡调节及动态有源滤波等功能,但控制策略是提高电能质量的关键。基于此提出一种基于串联电压补偿和并联电流补偿相协调的UPQC控制策略:首先分析UPQC的不同主电路拓扑结构的优缺点及不同结构的工作原理;其次分析谐波检测算法原理;提出一种左侧同相位串联电压补偿与右侧并联电流跟踪控制补偿策略相协调的控制策略,最后通过Simulink搭建UPQC模型。仿真表明通过串联电压补偿与并联电流补偿相协调控制策略模型的可行性,其能输出正弦波形,谐波畸变率较低。

As a large number of distributed new energy sources are connected to the distribution network,more and more power electronic equipment is connected to increase the nonlinear load of the transmission and distribution and load terminals,and the power quality problem of voltage and current waveform distortion occurs.In order to effectively solve the power quality problem comprehensively,the unified power quality conditioner(UPQC)can comprehensively solve the power quality,with functions such as reactive power compensation,three-phase unbalance adjustment and dynamic active filtering,but the control strategy is the key to improve power quality.Based on this paper,the control strategy of UPQC based on series voltage compensation and parallel current compensation is proposed.Firstly,the advantages and disadvantages of different main circuit topologies of UPQC and the working principles of different structures are analyzed.Secondly,the principle of harmonic detection algorithm are analyzed.A control strategy that coordinates the left in-phase series voltage and the right parallel current tracking control compensation strategy is proposed.Finally,the UPQC model is built by simulink.The simulation shows that the feasibility of the control strategy model is coordinated by voltage compensation and current compensation,and the sinusoidal waveform can be output with the low harmonic distortion rate.