链式静止同步补偿装置控制策略研究

Research on Control Strategy of Chain-circuit Static Synchronous Compensator

基于负序电流控制思想同时全面考虑系统电压不平衡对链式静止同步补偿装置的影响进行控制策略的研究。链节直流侧电容电压平衡控制是实现工程应用的关键问题,针对该问题设计了3级直流电压控制策略。第1级为全局平均直流电压控制,生成装置整体参考指令,解决装置整体直流侧电压稳定问题;第2级为换流链平均直流电压控制,对装置负序电流进行控制,实现相间直流侧电压平衡;第3级为链节直流电压控制,对每个链节分别进行控制,实现链节平衡。此处设计的控制策略通过实验证明具有良好的性能。

Based on the negative sequence current control idea and considering the influence of system voltage imbalance on the chain-circuit static synchronous compensation device,the control strategy is studied.Voltage balance control of link DC side capacitor is a key problem to realize engineering application,to solve this problem the three-level DC voltage control strategy is designed.The first level is global average DC voltage control,generating device overall reference command,solving the problem of voltage stability on the DC side of the whole device.The second level control is the average DC voltage control of converter chain,controlling the negative sequence current of the device,realizing the voltage balance of the phase to phase DC side.The third level control is link DC voltage control,controlling each link separately,achieving link balance.The control strategy designed is proved to have good performance by the experiment.