计及频率适应和快速稳定特性的多端直流电网改进协调控制策略  

Improved Coordinated Control Strategy of Multi-terminal DC Grids Considering Frequency Adaptation and Fast Stabilization Characteristics

作　　者：吴云锐 张建坡 田新成 应恺锋 陈忠 WU Yunrui;ZHANG Jianpo;TIAN Xincheng;YING Kaifeng;CHEN Zhong(Department of Electric Power Engineering,North China Electric Power University,Baoding 071003,China;State Grid Jibei Electric Power Company Limited Tangshan Power Supply Company,Tangshan 063000,China)

机构地区：[1]华北电力大学电力工程系,河北保定071003 [2]国网冀北电力有限公司唐山供电公司,河北唐山063000

出　　处：《中国电力》2025年第3期31-42,共12页Electric Power

基　　金：国家重点研发计划资助项目(响应驱动的大电网稳定性智能增强分析与控制技术,2021YFB2400800)。

摘　　要：多端柔性直流输电(voltagesourceconvertermulti-terminalDC,VSC-MTDC)技术在大规模、大范围多种类型可再生能源并网与外送方面具有广泛应用前景。针对柔性直流电网不平衡功率大扰动下交直流耦合对直流电压及交流系统频率影响问题,首先,提出基于直流电压下垂控制的改进协调控制策略,消除扰动前后直流电网电压偏离额定运行点问题;然后,通过引入自适应下垂系数,提高直流电网电压稳态恢复速率以及一定的控制可靠性。其次,对改进协调控制频率适应能力提升进行分析研究,以实现换流站参与交流系统频率调控,弥补交流侧调频能力缺失。最后,基于PSCAD/EMTDC搭建新能源经四端直流电网外送仿真模型,验证了所提改进协调控制策略及其对交流电网频率调控的可行性和有效性。Multi-terminal flexible DC transmission(VSC-MTDC)technology has a wide range of application prospects in large-scale and wide-range multiple types of renewable energy grid-connection and outward transmission.To address the influence of AC-DC coupling on DC voltage and AC system frequency under large unbalanced power disturbances of flexible DC network,an improved coordinated control strategy based on DC voltage sag control is firstly proposed to eliminate the DC network voltage deviation from the rated operation point before and after the disturbances.And then the adaptive sag coefficients are introduced to improve the DC network voltage steady state recovery rate and certain control reliability.Thirdly,the adaptive capacity enhancement of the improved coordination control frequency is analyzed in order to realize the participation of converter station in AC system frequency regulation and control,and to make up for the lack of AC-side FM capacity.Finally,a simulation model of new energy transmission via fourterminal DC grid is constructed based on the PSCAD/EMTDC,which verifies the feasibility and effectiveness of the proposed improved coordinated control strategy and its AC grid frequency regulation.

关 键 词：柔性直流电网 下垂控制 协调控制 加速策略 频率调控 

分 类 号：TM7[电气工程—电力系统及自动化]