一种抽能型高抗的抽能绕组匝间短路保护方案研究

抽能型高压并联电抗器，简称抽能高抗，实质是一台由网侧绕组和抽能绕组构成的空心型变压器，属于一种既能吸收系统多余无功也能提供站用电源的新型电抗器。目前，工程上通常采用抽能绕组过电流或零序过电流保护反映抽能绕组的匝间短路故障，存在着选择性差、动作时间长等不足。因此，提出一种新型的抽能绕组匝间短路保护方案以解决这一问题，即综合采用抽能高抗网侧绕组的电压和电流以及抽能绕组环内电流等电气量，由区外异常判据、铁芯饱和判据和自产零序过流判据以逻辑相与的方式共同构成。RTDS仿真实验表明，该保护方案，既能保证在各种非区内故障工况下可靠不动作，又能灵敏反映抽能绕组4%匝以上的匝间短路故障，并将保护动作时间缩短至50 ms左右，解决了以往抽能绕组匝间短路保护方案选择性差、动作时间长等问题。

A new scheme of inter-turn winding short circuit protection for energy extraction shunt reactor

The power extraction high voltage parallel reactor,referred to as energy extraction reactor, is essentially a hollow transformer consisting of grid-side windings and auxiliary windings. It belongs to a new type of reactor which can absorb the redundant reactive power of the system and provide the power supply for the station. At present, over-current or zero-sequence over-current protection is usually used in engineering to reflect the inter-turn short-circuit fault of the auxiliary windings. This protection scheme has some shortcomings, such as poor selectivity and long operation time. Therefore, in this paper, a new scheme of inter-turn winding short circuit protection for energy extraction reactor was proposed. The scheme integrates the voltage and current of the high reactance winding on the grid side and the current in the winding ring. It consists of the criterion of out-of-zone anomaly, the criterion of core saturation and the criterion of self-produced zero-sequence overcurrent in a logical phase. RTDS simulation results show that the protection scheme can not only ensure reliable operation under various non-regional fault conditions, but also reflect inter-turn short circuit fault of auxiliary winding more than 4%, and shorten the protection operation time to about 50 ms, thus solving the problems of poor selectivity and long operation time of previous inter-turn short circuit protection schemes for auxiliary winding.