海岛多能源微网故障免疫及谐波滤除的隔离变压器方案  

Research on an Isolation Transformer Solution for Fault Immunity and Harmonic Filtering in an Island Multi-Energy Microgrid

作　　者：黄俊翰 尹建华 马立红 赵进全[1] 和少寅 陈鹏宇 刘峰华 施金志 HUANG Junhan;YIN Jianhua;MA Lihong;ZHAO Jinquan;HE Shaoyin;CHEN Pengyu;LIU Fenghua;SHI Jinzhi(School of Electrical Engineering,Xi’an Jiaotong University,Xi’an 718000,China;Electric Power Research Institute,China Southern Power Grid,Guangzhou 510080,China;Hainan Power Grid Co.,Ltd.,China Southern Power Grid,Haikou 570203,China)

机构地区：[1]西安交通大学电气工程学院,西安718000 [2]南方电网科学研究院,广州510080 [3]南方电网海南电网有限责任公司,海口570203

出　　处：《西安交通大学学报》2024年第3期212-222,共11页Journal of Xi'an Jiaotong University

基　　金：国家自然科学基金资助项目(52007139)。

摘　　要：为解决某海岛微网系统面临的多能源发电单元易受外部故障解列及3倍次谐波自由传递导致系统电能质量低下等问题,提出一种综合电站出口增设隔离变压器的一次系统改进方案。基于该海岛微网的多能源结构、海岛环境、高可靠性要求等特殊应用场景,阐述隔离变压器方案,验证同步机组励磁系统缺陷及新能源发电单元导致的谐波来源;配合应用虚拟同步发电机的光伏蓄电池支路,通过系统故障电压支撑能力、三相/零序不平衡度及谐波畸变率量化隔离变压器方案,对发电单元隔离保护及系统电能质量的提升效果有促进作用。经电磁暂态平台PSCAD验证,新方案使发电单元免疫外部故障零序冲击,综合电站出口处电压支撑能力提高了52.44%,畸变度降低了78.04%,基本完全滤除占比14.33%的励磁缺陷谐波电流,具备传统滤波器方案不具备的故障免疫及谐振过电压抑制作用,为海岛多能互补电网工程建设提供参考性方案。To address the challenges faced by island microgrid system,such as the vulnerability of multi-source power generation units to external faults and the free transmission of triplen harmonics leading to poor power quality,this paper proposes a primary system improvement solution involving the installation of an isolation transformer at the power station’s point of common coupling(PCC).This paper elaborates on the new isolation transformer solution based on the island microgrid’s unique characteristics,including its multi-energy structure,island environment,and high reliability requirements.It also verifies the sources of harmonics resulting from defects in the excitation system of synchronous generators and the new energy generation units.Furthermore,in conjunction with the application of virtual synchronous generator(VSG)technology in a photovoltaic battery branch,this study quantifies the effects of the isolation transformer solution on the isolation protection of generation units and the enhancement of system power quality,with the system’s fault voltage support capability,three-phase/zero-sequence imbalance,and harmonic distortion rate.Lastly,the new solution is validated using the electromagnetic transient platform PSCAD.The results show that the solution provides immunity for generation units against external fault zero-sequence impacts.It also enhances the voltage support capability at the power station’s PCC by 52.44%,reduces distortion by 78.04%,and effectively eliminates 14.33%of harmonic currents associated with defects in the excitation system.This solution offers fault immunity and suppresses resonance-induced overvoltage,which cannot be achieved using conventional filter solutions.It provides valuable insights for the construction of island-based multi-energy complementary grids.

关 键 词：隔离变压器 海岛多能源微网 虚拟同步发电机 故障解裂 励磁模型 

分 类 号：TM72[电气工程—电力系统及自动化]