特高压有载调压变压器差动保护自适应算法

发布时间：2018-06-03 16:42

本文选题：特高压 + 调压变压器　；参考：《电工技术学报》2017年20期

【摘要】：有载调压技术已在中国特高压交流输电系统中实现了应用,这对特高压变压器运行的可靠性提出了更高要求。有载调压过程中,由于无法获知调压变压器的实际运行档位,差动保护装置不能根据实时的额定电流之比调整平衡系数,只能选取一个固定档位下调压变压器两侧额定电流之比来计算其差动电流,因而会造成很大误差。工程上,设置调压变压器不灵敏段差动来躲过调档产生的不平衡电流,这不仅增加了调压操作的复杂性,还降低了调压变压器差动保护的灵敏度。针对上述问题,基于特高压变压器电气结构提出一种在线自适应获取调压变压器运行档位的方法,通过实时计算调压变压器运行时的端电压之比,对差动电流计算结果进行修正,精确求得有载调压过程中调压变压器的实时差动电流。数字仿真证明了基于自适应算法的调压变压器差动保护动作特性不受短路匝数和运行档位变化影响,可有效解决现有特高压有载调压变压器差动保护策略识别匝间故障时灵敏度不足的问题。
[Abstract]:The on-load voltage regulation technology has been applied to the UHV AC transmission system in China, which puts forward higher requirements for the reliability of UHV transformer operation. In the process of on-load voltage regulation, the differential protection device can not adjust the balance coefficient according to the ratio of rated current in real time, because it is unable to know the actual operating gear of the voltage regulating transformer. The differential current can only be calculated by selecting one fixed gear to reduce the rated current ratio on both sides of the transformer, which will cause a great deal of error. In engineering, the differential of the insensitive section of the regulating transformer is set to avoid the unbalance current generated by the overadjustment, which not only increases the complexity of the voltage regulation operation, but also reduces the sensitivity of the differential protection of the voltage regulating transformer. In order to solve the above problems, based on the electrical structure of UHV transformer, an on-line adaptive method for obtaining the operating gear of voltage regulating transformer is proposed, and the ratio of terminal voltage to voltage during operation of the transformer is calculated in real time. The calculation results of differential current are corrected and the real time differential current of transformer during on-load voltage regulation is accurately obtained. The digital simulation proves that the operation characteristics of differential protection of voltage regulating transformer based on adaptive algorithm are not affected by the number of short circuit turns and the change of running gear. It can effectively solve the problem that the sensitivity of the existing differential protection strategy of UHV on-load transformer for inter-turn fault identification is insufficient.
【作者单位】：新能源电力系统国家重点实验室(华北电力大学);江苏省电力公司南京供电公司;
【基金】：国家重点研发计划智能电网技术与装备重点专项(2016YFB0900604) 国家自然科学基金(51677069)资助项目
【分类号】：TM774

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