STATCOM对直流融冰整流变压器直流偏磁的影响及抑制方法

Influence of STATCOM System on the DC-icing Rectifier Transformers' DC Magnetization and Suppression Method

利用12脉动直流融冰装置的整流变压器将静止无功发生器(STATCOM)接入交流电网,可以使整流变压器得到充分利用,为系统提供动态无功支撑,并有效改善融冰方式运行时的电能质量。针对STATCOM系统中整流变压器的直流偏磁问题,对1台链式STATCOM样机中的变压器直流偏磁现象进行了试验研究和分析,并提出了链式逆变器的直流分量控制方法和针对整流变压器的最大直流电流分量控制方法,该方法可以有效抑制整流变压器的直流偏磁。所提出直流偏磁抑制方案的有效性通过在30 k VA链式STATCOM样机上得到试验验证,一旦检测到有直流电流分量,直流偏磁抑制分量就会很快起作用,使变压器铁芯停止偏磁过程,并回到正常状态。

Static synchronous compensator（STATCOM） can be integrated into AC grid through the rectifier transformer of 12-pulse DC ice melting device, which can make the rectifier transformer to be fully utilized, so it can provide dynamic reactive support for the system and effectively improve the power quality of ice melting mode. According to the DC bias magnetic problem for the rectifier transformer in STATCOM system, the DC magnetization phenomenon is researched and analyzed based on the experimental results of a cascaded STATCOM. The DC component control method of the cascaded inverter and the maximum DC current voltage control method are proposed, which can effectively suppress the DC bias of the rectifier transformer. The effectiveness of the proposed DC bias suppression scheme is verified by the experimental results on the 30 k VA cascaded STATCOM. Once the DC current component is detected, the DC bias magnetic suppression component will be very fast until the magnetic core of the transformer can be stopped and return to normal state.