针对异步分区后电力系统调频资源不足、频率响应恶化等问题,提出了一种基于电网换相换流器型高压直流输电(line commutated converter high voltage direct current,LCC-HVDC)的异步互联系统双向主动频率控制策略.该策略通过灵活地调整直流电流和直流电压,在实现双侧频率调节的同时,保持逆变侧消耗的无功功率不变,最小化交流电压的波动.此外,为避免调节过程中,控制指令不当导致的换相失败问题,所提策略在设计过程中兼顾了最小熄弧角约束,保证了直流系统在频率调节过程中的稳定运行.在利用LCC-HVDC互联的四机两区域(four machines two areas,4G2A)系统进行仿真验证,证明了所提方法的有效性.本研究为异步互联系统的频率控制提供了一种新的解决方案,具有广阔的应用前景.
Bilateral active frequency control strategy for asynchronous interconnected systems based on LCC-HVDC
To address the issues of insufficient frequency regulation resources and deteriorating frequency response in asynchronously interconnected power systems,this study introduces a bidirectional active frequency control strategy based on LCC-HVDC.This strategy achieves bidirectional frequency regulation and ensures constant reactive power consumption on the inverter side by adjusting the DC current and voltage,which minimizing fluctuations in AC voltage.Furthermore,to prevent commutation failures caused by inappropriate control actions during adjustments,the proposed strategy incorporates a minimum extinction angle constraint,ensuring stable DC system operation during the frequency regulation process.This study provides a novel solution for frequency control in asynchronously interconnected systems,offering significant potential for practical applications.
asynchronously interconnected systemsbilateral frequency supporthigh voltage direct current transmissionvoltage controlreactive power