分时段直流多落点系统紧急及阻尼协调控制  

Time-Interval Coordinated Emergency and Damping Control for HVDC Multi-Terminal Transmission System

作　　者：吴霞[1] 刘天琪[1] 李兴源[1] 程道卫 

机构地区：[1]四川大学电气信息学院,四川省成都市610065 [2]合肥供电局,安徽省合肥市230022

出　　处：《电网技术》2013年第3期808-813,共6页Power System Technology

基　　金：国家自然科学基金项目(51037003);国家863高技术基金项目(2011AA05A119)~~

摘　　要：高压直流输电(high voltage direct current,HVDC)由于快速响应和短时过载特性对紧急控制或功率突然严重缺额地区进行紧急功率支援作用巨大,同时能很好解决区域振荡问题。利用PSCAD/EMTDC建立3机3直流系统的仿真模型,然后,在不添加任何直流附加控制的情况下,分别对正常运行的HVDC1、HVDC2和HVDC3的控制系统施加与功率增量P对应的调制指令,利用Prony辨识分析发电机功角差,找出有效抑制交流系统振荡的直流控制点。并根据最优变目标理论,在HVDC1停运时以最大能量耗散原理为基础利用故障驱动和轨迹驱动分时段进行紧急控制和阻尼控制,研究大扰动后交直流系统恢复稳定情况。结果表明利用分时段紧急协调控制且只在有效控制点进行后时段(即第2和第3时段)直流小方式调制能有效提高系统暂态稳定,改善系统后续阻尼,防止过/欠控及后续摆阻尼降低现象发生,使系统快速恢复稳定。Relying on its fast response and short-time overload capability,HVDC power transmission system can effectively perform emergency control or provide emergency power support to the region where sudden and serious power shortage occurs,meanwhile the inter-area oscillation can be well coped with.Utilizing PSCAD/EMTDC,firstly a simulation model composed of three generators and three DC transmission lines,named after HVDC1,HVDC2 and HVDC3 respectively,is constructed;secondly applying the same modulation instruction corresponding to power increment P to the control systems for the three HVDC lines separately without any DC additional control strategy,and angle differences among generators are identified by Prony analysis to find DC control point that can effectively suppress the oscillation occurred in AC system.Under the circumstance of large disturbance caused by sudden out of operation of HVDC1,based on the principle of the maximum energy dissipation and according to the theory of optimal variable-aim control the time-interval coordinated emergency and damping control,in which whether the driving mode of the controller is based on fault driving or based on trajectory driving is dependent to system status and fault status,is performed to research the stability recovery situation of the AC-DC system after the large disturbance.Research results show that only time-interval coordinated emergency and damping control is performed at effective DC control point since the second time-interval while the DC small mode modulation is adopted,the system stability can be enhanced effectively,and the follow-up damping can be improved to prevent the occurrence of over/under control and the decrease of damping for follow-up swings to make the system stability rapidly recovered.

关 键 词：直流多落点 紧急控制 最大能量耗散 最优变目标控制 阻尼控制 PRONY辨识 

分 类 号：TM73[电气工程—电力系统及自动化]