多分支移相变压器差动保护技术研究及应用

Research and application of differential protection for multi-branch phase-shifting transformer

分析了传统移相变压器保护方案的缺点,对移相变压器的工作原理进行了详细研究,推导了适用于各种移相变压器的电流变换关系,并提出了一种采用全角度移相、数字化采样等技术的移相变压器差动保护方案。所提差动保护方案解决了传统多分支移相变压器无法配置差动保护的问题,使得保护性能得到了极大提升,并可适用于不同类型的移相变压器。通过RTDS数模仿真实验,对所提方案的差动保护功能进行了实验验证。目前,基于该方案的差动保护装置已于2017年3月投运并稳定运行至今。

The shortages of traditional protection for phase-shifting transformer arc analyzed, the working principle of phase-shifting transformer is studied in detail, the current conversion relationship suitable for different types of phaseshifting transformer is deduced, and a new digital differential protection scheme using full-angle phase-shifting and digital sampling technology is proposed. The proposed scheme solves the problem that differential protection cannot be equipped in traditional multi-branch phase-shifting transformers, greatly improves the performance of protection system, and is suitable for different types of phase-shifting transformers. The effectiveness and correctness of the pro- posed scheme are verified by the simulation carried out with RTDS. The differential protection device applying the proposed scheme has been put into operation in March 2017,and has operated stably since then.