考虑动态电压区间无功支撑的双馈风机连锁故障穿越控制策略  

Cascading Fault Ride-through Control Strategy for Doubly-fed Wind Turbines Considering Reactive Power Support in Dynamic Voltage Range

作　　者：姜惠兰[1] 王绍辉[1] 李希钰 肖瑞[1] JIANG Huilan;WANG Shaohui;LI Xiyu;XIAO Rui(Smart Grid Key Laboratory of the Ministry of Education,Tianjin University,Tianjin 300072,China)

机构地区：[1]天津大学智能电网教育部重点实验室,天津300072

出　　处：《高电压技术》2022年第1期147-155,共9页High Voltage Engineering

基　　金：国家自然科学基金(51477115)。

摘　　要：造成大规模风电机组脱网的低高电压连锁故障近年频发,而现有穿越方案多立足于单一电压骤变故障进行暂态分析及策略制定。从对双馈异步风力发电机(doubly-fed induction generator,DFIG)的暂态冲击和对其无功需求两方面分析低高电压连锁故障的特点,并以最大限度发掘故障期间DFIG的无功支撑能力为出发点,确定其在故障各阶段的无功电流极限和背靠背变流器的无功调节优先级,进而给出无功分配方案以满足电网故障带来的无功需求。在此基础上,提出了兼顾DFIG故障穿越指标和故障各阶段电网无功需求的协调控制策略,即在利用DFIG转子电压补偿项抑制转子过电流的前提下,采用考虑动态电压区间的无功支撑方式,以及协调调用DFIG定子侧和网侧变流器的无功出力,实现对系统电压恢复作用,同时有效改善了高电压阶段电压及转子电流的越限程度,降低了DFIG发生脱网的风险。仿真结果表明所提控制策略有利于DFIG连锁故障期间穿越性能和无功支撑效果。The under and over-voltage cascading faults that cause large-scale wind turbines to disconnect from the grid have occurred frequently in recent years,but the existing ride-through solutions are mostly based on a single voltage sudden change fault for transient analysis and strategy formulation.We analyzed the characteristics of under and over-voltage cascading faults from two aspects,namely,transient impact of doubly-fed induction generator(DFIG)and reactive power demand of the grid.Starting from the maximization of the reactive power support capability of the DFIG,we determined the reactive current limit and the reactive power adjustment priority of the back-to-back converter at each stage of the fault,and then put forward the reactive power distribution plan to meet the reactive power demand.On this basis,we proposed a coordinated control strategy in which the DFIG fault ride-through index and the reactive power demand of the grid were taken into account.Under the premise of using the DFIG rotor voltage compensation item to suppress the rotor overcurrent,the reactive power support method considering dynamic voltage range was adopted,and the reactive power output of the DFIG stator-side and grid-side converters were coordinated to realize the recovery of the system voltage.Thus the over-limit degree of the voltage and rotor current in the high-voltage phase is effectively improved,and the risk of DFIG disconnection is reduced.The simulation results show that the proposed control strategy is beneficial to the ride-through performance and reactive power support effect during DFIG cascading faults.

关 键 词：风力发电 双馈风力发电机 低高电压连锁故障 无功支持 协调控制 变流器 

分 类 号：TM614[电气工程—电力系统及自动化]