矿用变电站STATCOM双机运行问题

国家对电能质量的要求愈来愈高,无功补偿及谐波治理问题是制约电能质量提高的关键因素。STATCOM作为目前中低压无功补偿及谐波治理领域的最先进技术,得到了广泛的应用。由于对电力系统稳定性的依赖,大部分矿用变电站都采用多台变压器并联运行,而单台STATCOM的装置容量都有限,在大部分场合都采用同时安装多台STATCOM装置在并联变压器的二次侧。由于受负荷不均的影响,变压器间会存在一定的能量流动。能量的流动会使补偿装置间形成环流震荡,甚至使装置输出电流发散,使补偿系统崩溃,这对变压器并联运行工况下的无功补偿及谐波治理问题提出了新的挑战。提出了一种基于硬件采样改进的简化分布式互联控制方法,有效的避免了装置间的环流和电流发散问题,可对多台变压器并联运行的无功补偿及谐波治理问题研究提供参考。

Assisted running STATCOM in mining substation

The request of power quality is more and more strict in our country these years，and the reactive power compensation and harmonic control problems are the key factors to improve the power quality.STATCOM is the most advanced technology in middle and low voltage reactive power compensation and harmonic control fields now，and has been widely used.Now due to the dependence of the stability in power system，multiple transformers were using in most mining substation with parallel operation mode.But because of the capability of single STATCOM was very limited，Multiple STATCOM devices were used on the secondary side of parallel transformers.Affected by the load’s unbalance，there were some energy flowing between the transformers.The flowing energy will cause the current’s circulation and oscillation among the devices，even cause the devices outputting current radiating and make the system worse，and it’s a new challenge for the reactive power compensation and harmonic control in the parallel transformers’ operation.A new control strategy of improved distributed interconnection based on new sampling method in hardware was proposed，avoids the problems of the current’s circulation among devices and the current’s divergence effectively，it has a important practical significance for the reactive power compensation and harmonic control in the parallel operation of multiple transformers.