基于有源换相换流器的交直流智能配电网控制策略

Control Strategy for ACC Based AC-DC Intelligent Distribution Network

为了实现配电网潮流的优化分配和光伏、电动汽车、储能电池等直流负荷高效可靠接入城市配电网,提出了一种基于有源换相换流器(active commutated converter,ACC)的交直流智能配电网系统。提出的系统采用ACC连接交流配电网实现潮流的优化分配,采用基于有源换相换流器-电压源换流器混合的直流变换器(DC/DC converter)实现分布式直流负荷的有效并网。分析了有源换相换流器和混合直流变换器的数学模型,提出了一种适用于交直流智能配电网系统的综合控制策略,实现了系统内所有换流器的单位功率因数运行,分析了系统直流短路故障特性。在PSCAD/EMTDC和RT-LAB半实物仿真平台中搭建了基于ACC的交直流智能配电网模型。仿真和实验结果表明,在正常工况下提出的控制策略能够实现所有换流器的单位功率因数运行。当直流故障发生时,所提出的控制策略能够实现系统平稳穿越。

To efficiently and reliably realize the optimal distribution of power flow in the distribution network and connect PV,electric vehicle,energy storage battery and other DC loads into urban distribution network,an active commutated converter(ACC)-based AC-DC intelligent distribution network is proposed.The proposed network adopts ACC to connect AC distribution network for power flow optimization and ACC-voltage source converter(VSC)based hybrid DC/DC converter for DC loads connection to the distribution network.The mathematical models of ACC and VSC are analyzed.A comprehensive control method which can be adopted to realize all the converters of the system operating at unity power factor states is proposed.The DC fault characteristics of the system is presented.Finally,the simulation and experimental model of the ACC based AC-DC intelligent distribution network is built on the PSCAD/EMTDC software and RT-LAB real time simulation platform.The simulation and experiment results verify that the proposed method can realize all the converters of the system operating at unity power factor at normal state and the system can smoothly ride through when the DC fault occurs.