摘要
±1100 kV特高压直流输电工程受端将采用分层接入方式,高、低端换流器分别接入500 kV和1000 kV层级电网。为解决常规控制策略无法独立控制逆变侧换流器输送功率的问题,提出了改进附加功率协调控制策略,通过在直流系统两侧加入附加控制器,实现对两侧传输功率更加灵活的控制。同时,为保证对功率进行紧急提升时,将功率提升指令合理分配给同级串联高、低端换流器,定义了功率分配系数,提出功率分配策略,实现对逆变侧各换流器提升功率的协调控制。通过仿真验证了改进附加功率协调控制策略在系统正常运行、受端功率指令下降、交流母线电压上升等工况下,能够实现对逆变侧换流器输送功率的灵活控制。功率分配策略在功率紧急提升时,能够将同极提升的直流功率在串联换流器中进行合理分配,有利于充分利用各换流器的功率输送能力,保证各换流器熄弧角留有较大的裕度,减少换流器发生换相失败的概率。
± 1100 kV UHVDC transmission project will adopt hierarchical connection mode at its receiving end with its high and low converters integrated to 500 kV and 1000 kV AC grids respectively on inverter side.To solve the problem that conventional control strategy cannot control transmission power independently,an improved additional power coordinated strategy is proposed.To reduce probability of commutation failure in each converter during power lifting emergency,power distribution coefficient and power allocation strategy are proposed.The lifted power will be allocated to each converter coordinatively.Simulation results show that the improved additional power coordinated control strategy can control the transmission powers of the converters flexibly and coordinatively.The lifted power can be reasonably allocated to each converter using power allocation control strategy in power emergency control.It will make full use of the power transmission capacity of each converter to ensure a large margin of arc angle of each converter and reduce probability of commutation failure in each converter.
出处
《电网技术》
EI
CSCD
北大核心
2017年第11期3448-3456,共9页
Power System Technology
基金
国家重点研发计划资助项目(2016YFB0900800)~~
关键词
±1100
KV
分层接入
改进附加功率协调控制
分配系数
功率分配策略
± 1100kV
hierarchical connection
improvedadditional power coordinated control
allocation coefficient
power allocation control strategy
