交直流混杂环境下基于关键参数辨识的变压器直流偏磁保护策略研究

项目名称： 交直流混杂环境下基于关键参数辨识的变压器直流偏磁保护策略研究

项目编号： No.51507027

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 电工技术

项目作者： 潘超

作者单位： 东北电力大学

项目金额： 21万元

中文摘要： 高压直流输电和磁暴灾害等条件下直流扰动通过接地中性点注入交流电网，导致了交直流混杂环境下的变压器直流偏磁问题。变压器直流偏磁时电流、电感等参数发生畸变，使依赖于这些参数的保护出现误动和拒动问题，从而对设备乃至电网的安全稳定运行造成巨大危害。本项目针对变压器直流偏磁引起的保护问题，拟结合基于电感参数的变压器保护方法，在思想上突破传统以电路或磁路计算为基础的变压器保护，基于能量扰动原理建立计及直流偏磁的场路耦合模型，利用电感等关键参数表征变压器直流偏磁电磁特性，构建偏磁效应量化评价指标将故障特征与关键参数关联，通过理论分析、数值仿真与实验模拟相结合的方法，从电磁耦合角度深入分析变压器偏磁效应的物理本质，开展基于参数辨识的变压器直流偏磁效应评估与保护策略研究。项目研究能够提高变压器等电磁设备及交流电网抗直流扰动的安全稳定性，将在变压器直流偏磁保护方面形成鲜明特色与创新。

中文关键词： 交直流混杂；电磁耦合；参数辨识；保护

英文摘要： The DC-biased transformer have affacted safety and stability of power system in the AC-DC hybrid environments such as high-voltage direct-current transmission and the magnetic storm in power network. As the nonlinear exciting characteristic is susceptible to the DC disturbance, the traditional protections operate with risk and can not solve the abnormal matters in transformer such as vibration, overheat and so on. In this project, the problems above will be researched with the application of inductance in novel principle of protection. The field-circuit coupled method for DC-biased transformer is built from the point of energy transforming. The time-domain current and dynamic inductance are used as key parameters in the characterization of saturated excitation of transformer. The variation of the key parameters, excitation and harmonics is analyzed with DC disturbance. And the inherent relations between exciting saturation and key parameters with DC-biasing disturbance will be explored. On this basis of key research on parameter identification, the quantitative evalutation index of DC-biasing effect is determined. Thus the abnormal matters in transformer can be associated with the key parameters. The protect criterion can be put forward based on the parameter identification, and the assessment and protection for DC-biased transformer will be realized. The main research achievements will have important scientific value and practical meanning to improve the DC immunity of electromagnetic devices as transformer and power system, which takes significant feature and innovation in the protection for DC-biased transformer.

英文关键词： AC-DC hybrid ;electromagnetic coupling;parameter identification;protection