网侧电压跌落下计及无功支撑效能的直流微电网多目标优化策略  

Multi-objective Optimization Strategy of DC Microgrid Based on Reactive Power Support Efficiency During Voltage Sag

作　　者：曹善康 魏繁荣[1] 林湘宁[1] 李正天[1] 肖澍昱 汪涛[1] 徐昂 CAO Shankang;WEI Fanrong;LIN Xiangning;LI Zhengtian;XIAO Shuyu;WANG Tao;XU Ang(State Key Laboratory of Advanced Electromagnetic Engineering and Technology(Huazhong University of Science and Technology),Wuhan 430074,Hubei Province,China)

机构地区：[1]强电磁工程与新技术国家重点实验室(华中科技大学),湖北省武汉市430074

出　　处：《中国电机工程学报》2023年第15期5759-5771,共13页Proceedings of the CSEE

基　　金：国家电网有限公司总部科技项目(5100-202199545A-0-5-ZN)。

摘　　要：当直流微网的并网点电压由于网侧故障等因素发生短时跌落时,并网换流站通常采取最低限度的无功输出策略,以尽量保留直流微网安全运行所需的有功调节裕度。然而,大量案例表明,上述策略过于偏重换流站有功调节裕度对直流微网自身安稳的影响,而忽视了主动无功支撑对交流电网安稳的积极意义。为了获得更为合理的换流站有功-无功分配方式及对应微网控制策略,首先,构建网侧电压跌落期间换流站有功安全裕度-无功支撑效能的量化评估模型。随后,通过分析系统层面的有功平衡与直流电压波动转换关系,以及元件层面的微网内部各元件短时工作限制,获得直流微网在有功调节和无功支撑过程中的动态约束条件。在此基础上,基于INSGA2-DS算法以统筹优化换流站的无功支撑效能与有功安全裕度。考虑到在线应用场景下INSGA2-DS算法的求解时间较长,难以适配电压跌落的时间尺度,提出了“准同步计算,实时匹配”的时序优化策略。针对分布式电源的波动性对准同步计算时效性的负面影响,同步设计一种帕累托曲线映射规则以修正前沿曲线偏差。最后,大量算例仿真验证了所提模型和策略能够获得的有效性。When the voltage of parallel point of DC microgrid falls in a short time due to network side faults and other factors,the grid connected converter station usually output minimum reactive power to keep the active power adjustment margin required for the safe operation of DC microgrid as far as possible However,a large number of cases show that this strategy pays too much attention to the influence of active power margin of converter station on the stability of DC microgrid,and ignores the positive significance of more active and abundant reactive power support on the stability of AC power grid.In order to obtain a more reasonable active-reactive power distribution mode of converter station and corresponding micro-grid control strategy,this paper first constructs a quantitative evaluation model of active power safety margin and reactive power support efficiency of converter station during the voltage sag on the network side.Then,the dynamic constraints in the active power regulation and reactive power support of the DC microgrid are obtained by analyzing the conversion relationship between the active power balance and the DC voltage fluctuation at the system level and the short-term operating constraints of the components in the microgrid at the component level On this basis,The reactive power support efficiency and active power safety margin of converter station were optimized based on INSGA2-DS algorithm.In the process of online application,considering the long calculation time of INSGA2-DS algorithm,it is difficult to adapt to the time scale of voltage sag,a timing optimization strategy of“quasi-synchronous calculation,real-time matching”is proposed.A Pareto curve mapping rule is designed to correct the leading edge curve deviation because of the negative effect of the fluctuation of distributed power supply on the timeliness of quasi-synchronous calculation.Finally,the effectiveness of the proposed model and strategy is verified by a large number of numerical examples.

关 键 词：直流微网 低电压穿越 多目标算法 无功补偿 多源协调控制 

分 类 号：TM721[电气工程—电力系统及自动化]