三相五柱偏磁式接地消弧变压器及其自动调谐

MAGNETIC BIAS BASED ARC-SUPPRESSION TRANSFORMER WITH THREE PHASES AND FIVE COLUMNS AND ITS TUNING

提出了一种偏磁式接地消弧变压器。它由1个五柱铁心和7个绕组组成;中间三柱铁心和绕组连接成三相Z型接地变压器;两边柱和绕组构成偏磁式消弧线圈。其功能相当于1台接地变压器和1台消弧线圈,用于无中性点引出的中压电网。制造出6kV,50A的样机并进行了相关实验研究,依据调节特性,可以通过控制偏磁电流精确地调节接地消弧变压器电感。采用了注入工频电流法测量电网电容电流,并对该方法的误差特性进行了分析。开发出基于单片机的调谐控制器并进行了低压模拟试验。成套装置经1年多工业运行,效果令人满意。

Firstly, an arc-suppression transformer is presented with three phases and five limbs based on magnetic bias, which consists of an iron core with five limbs and seven coils. The object acts as an earth-transformer composed of three limbs and their coils in the middle with Z-link. The two side limbs and their coils make up of the arc-suppression system based on magnetic bias. The arc-suppression transformer plays as an earth-transformer and an arc-suppression in the MV network without neutral point. A sample of 6 kV 50 A is made and relevant tests are carried through. Depending on the adjustment characteristic, the inductance of arc-suppression transformer can be accurately adjusted by controlling the magnetic bias current. Moreover, a method of measuring the network capacity current by injecting a 50 Hz current is applied into the neutral point and the error characteristic is analyzed. Finally, a controller based on microprocessor is developed and validated on the low voltage simulation network. A set of equipment has been operated on MV power distribution networks and the result is satisfactory.