电网电压不平衡时VSC-HVDC优化控制策略  

Optimization Control Strategy for VSC-HVDC with Unbalanced Grid Voltage Conditions

作　　者：孙黎霞[1] 王哲[1] 朱鹏飞[1] 陈宇[1] 金宇清[1] 

机构地区：[1]河海大学能源与电气学院,南京210098

出　　处：《高电压技术》2016年第1期47-55,共9页High Voltage Engineering

基　　金：国家自然科学基金(51137002;51190102);国家重点基础研究发展计划(973计划)(2013CB228204)~~

摘　　要：电网电压不平衡时,引起电压源换流器输出功率的二倍频波动。为此,研究了两相静止αβ坐标系下的电压源换流器高压直流输电(VSC-HVDC)电网电压三相不平衡时的功率优化控制策略。为了方便计算不同控制目标下的参考电流,引入两个独立可调的参数,推导参考电流的统一解析表达式。提出采用粒子群算法对两个独立参数进行优化,同时抑制有功功率和无功功率二倍频波动,实现多目标控制。并采用比例谐振控制器进行矢量电流控制,实现交流信号无静差控制。在PSCAD/EMTDC中进行仿真验证,结果表明,当发生单相接地故障时,采用文中提出的功率优化策略,当有功功率波动不超过10%时,无功功率的波动减弱20%,仿真结果和理论分析相一致,验证了所提出的优化控制策略的有效性和可行性。Unbalanced grid voltage will lead to double frequency fluctuation power in voltage source converter. We put forward an optimization control strategy for power control of VSC-HVDC under unbalanced grid voltage conditions in the stationary aft reference frame. For simple implementation and flexible operation, introducing two individually adapta- ble parameters, the current references are derived and synthesized into one generalized equation aiming to manipulate different control objectives. A parameter optimization method based on particle optimal swarm（PSO） algorithm is pre- sented to determine the two parameters, which can restrain the double frequency reactive and active power oscillations at the same time. It is preferred to choose a PR controller which can achieve zero steady state error in ctl3 stationary coordi- nate. The proposed strategies have been investigated by PSCAD/EMTDC. The simulation results demonstrate that the reactive power oscillation reduces by 20% while the active power fluctuation is limited to less than 10% when single phase fault occurs. The expected performance of theoretical analysis validates the effectiveness and feasibility of the pro- posed method.

关 键 词：柔性直流输电 电压源换流器 不平衡控制 参数优化 粒子群 比例谐振控制 功率波动 

分 类 号：TM721.1[电气工程—电力系统及自动化]