摘要
特高压直流输电在电网中的应用越来越广泛,送端电网与受端电网间采用多回直流相连,在一回直流故障时,通过提升其他直流实现功率紧急支援。在受端电网相对较弱的情况下,当需要大幅紧急提升直流功率时,如逆变侧采用传统修正的定熄弧角控制,会出现换相失败的情况。为此,分析了产生换相失败的原因及交流系统强度和提升量对换相失败的影响,并在现有逆变侧控制策略的基础上,提出一种预防换相失败的控制器,通过引入熄弧角测量值,实现熄弧角闭环控制,从而保证换相裕度,避免换相失败。在实时数字仿真系统(RTDS)中进行了试验验证,结果表明,所提策略可解决特高压直流大幅提升功率时的换相失败问题。
UHVDC is more and more widely used in power grid,and multi-HVDC is adopted to connect the sending and receiving power grids.When one HVDC fault occurs,emergency power support is realized by runup other HVDC.In the case of weak receiving power grid,when one HVDC needs runup greatly,commutation failure will occur if the traditional extinguishing angle control strategy is adopted on the inverting side.Therefore,the causes of commutation failure and the influence of AC system strength and runup amount are analyzed.Then,an improved extinguishing angle control strategy on the inverter side is proposed,which introduce extinction angle measure value into the controller and realize closed-loop control,so as to ensure commutation margin and avoid commutation failure.Then experimental verification is carried out on RTDS simulation system,and test results show that the proposed strategy can solve the commutation failure problem when runup HVDC with weak receiving end greatly.
作者
李林
吕彦北
王永平
付广旭
卢东斌
LI Lin;LYU Yanbei;WANG Yongping;FU Guangxu;LU Dongbin(NR Electric Co.,Ltd.,Nanjing 211102,China)
出处
《电力工程技术》
北大核心
2021年第1期208-214,共7页
Electric Power Engineering Technology
基金
国家电网有限公司总部科技项目(SGJSJY00JCJS1800115)。
关键词
直流输电
弱交流系统
紧急提升
换相失败
定熄弧角控制
ultra high-voltage direct current(UHVDC)
weak AC system
emergency runup
commutation failure
constant gamma control
