基于测后模拟原理的新能源送出线路前行波纵联保护OA
Forward Traveling Wave Pilot Protection for Renewable Energy Outgoing Lines Based on Post-Test Simulation Principle
[目的]大规模新能源并网场景下,新能源电源故障电流呈现幅值受限、频率偏移、相位畸变等特征,致使传统工频相量型保护适应性不足,易发生误动或拒动问题.为此,提出一种基于测后模拟原理的前行波纵联保护方法.[方法]首先,分析新能源电源故障特征,发现全功率逆变型电源与双馈风电机的故障电流特征与传统同步发电机存在显著差异,这种差异导致了传统保护适应性不足;其次,提出测后模拟保护原理,推导了无损传输线路的电压和电流方程,在此基础上,考虑线路的电阻损耗,定义线路保护测点推导至线路内部任意点处的模拟电压和电流的表达式;最后,以线路中点为模拟点,计算线路两端测点向中点推算的模拟电压前行波,利用区内外故障时的波形差异实现故障识别.[结果]基于PSCAD/EMTDC搭建"风光储"送出系统进行仿真验证.结果表明,所提保护仅需2 ms时间窗即可实现故障识别,能耐受300 Ω过渡电阻与30 dB信噪比白噪声干扰,且在新能源出力改变场景下具有较好的适应性.[结论]所提方法属于暂态量保护,不依赖工频相量与故障电流幅值,有效避免了新能源故障特性对传统保护的影响,具备较好的综合性能与工程实用性,适用于新能源送出线路纵联保护.
[Objective]Against the background of large-scale renewable energy integration,the fault currents of renewable energy sources exhibit characteristics such as limited amplitude,frequency offset,and phase distortion.This leads to the insufficient adaptability of traditional power-frequency phasor-based protection,making it prone to maloperation or failure to operate.To address this issue,a forward traveling wave pilot protection method based on the post-test simulation principle is proposed.[Methods]Firstly,an analysis of the fault characteristics of renewable energy sources reveals that the fault current characteristics of full-power converter-interfaced sources and doubly-fed induction generators are significantly different from those of traditional synchronous generators,which leads to the poor adaptability of traditional protection.Secondly,the post-test simulation protection principle is proposed,and the voltage and current equations of lossless transmission lines are derived.On this basis,considering the resistance loss of practical lines,the expressions of simulated voltage and current are defined to calculate the quantities from the protection terminals to any internal point of the line.Finally,taking the line midpoint as the simulation point,the simulated forward voltage traveling waves extrapolated from both ends to the midpoint are calculated,and fault identification is achieved based on the waveform differences between internal and external faults.[Results]A simulation model of the wind-PV-storage transmission system is built in PSCAD/EMTDC to verify the applicability of the proposed protection.The results show that the proposed protection requires only a 2 ms data window for fault identification,can tolerate a transition resistance of up to 300 Ω and white-noise interference at a signal-to-noise ratio of 30 dB,and exhibits good adaptability to variations in renewable energy output.[Conclusions]The proposed method is a transient-quantity-based protection method that does not rely on power-frequency phasors and fault current amplitudes.It effectively avoids the adverse impacts of renewable energy fault characteristics on traditional protection,demonstrates good comprehensive performance and engineering applicability,and is suitable for pilot protection of renewable energy outgoing lines.
石恒初;王鸿宇;雷顺广;陈晓帆;李银银;游昊;周海成;束洪春
云南电网有限责任公司,昆明市 650011昆明理工大学电力工程学院,昆明市 650500昆明理工大学电力工程学院,昆明市 650500云南电网有限责任公司,昆明市 650011云南电网有限责任公司,昆明市 650011云南电网有限责任公司,昆明市 650011云南电网有限责任公司普洱供电局,云南省 普洱市 665000昆明理工大学电力工程学院,昆明市 650500
信息技术与安全科学
大规模新能源送出线路纵联保护测后模拟原理行波
large-scale renewable energyoutgoing linepilot protectionpost-test simulation principletraveling wave
《电力建设》 2026 (10)
62-74,13
国家自然科学基金项目(52037003)中国南方电网公司科技项目(YNKJXM20240531)云南省基础研究计划(202401BE070001-014) This work is supported by National Natural Science Foundation of China(No.52037003),Science and Technology Project of China Southern Power Grid Co.,Ltd.(No.YNKJXM20240531)and the Yunnan Fundamental Research Projects(No.202401BE070001-014).
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