An improved current-limiting control strategy for shunt active power filter
An improved current-limiting control strategy for shunt active power filter
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DOI：
10.1109/ipemc.2016.7512478
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发表时间：
2016-05
期刊：
影响因子：
--
通讯作者：
Sheng Xu
中科院分区：
文献类型：
--
作者：
Sheng Xu
配电网发生短路或开路故障时，往往会产生很强的冲击电流，从而导致并联型有源电力滤波器（SAPF）过流故障。因此，本文提出了一种新的SAPF限流控制策略。利用该方法，当补偿指令电流中的一个或多个相电流超过瞬时电流极限时，具有最大瞬时绝对值的相电流的超过部分被截断，而其它相电流被成比例地限制。理论分析、仿真和实验结果表明，一方面，与传统的比例限流控制方法相比，新方法具有更快的响应速度，克服了过流保护延时问题;另一方面，与传统的截断限流控制方法相比，指令电流之和等于零，没有额外的谐波电流，尤其是3 k次谐波电流，其中k = 1，3，5，.，在三相四线制系统中，中性线上不存在多余的零序谐波电流。结果表明，有源滤波器具有最佳的补偿效果，使流入电力系统的谐波电流最少。
Some types of short-circuit or open-circuit fault in the distribution power system usually bring about a strong impulse current, which will result in the over-current fault of the shunt active power filters (SAPF) connected in the distribution power system to suppress the harmonic currents. Therefore, a novel current-limiting control strategy for SAPF is proposed in this paper. With this method, when one or more phase currents of the compensation instruction currents exceed the instantaneous current limit, the exceeded part of the phase current having the maximum instantaneous absolute value is truncated, while the other phase currents are limited proportionally. Theoretical analysis, simulation and experimental results show that, on the one hand, compared with the traditional proportional current-limiting control method, the new method has much faster response speed to overcome the problem of over-current protection delay; on the other hand, compared with the traditional truncated current-limiting control method, the sum of the instruction currents equals to zero, so no extra harmonic currents, especially 3k-th harmonic currents, where k = 1, 3, 5, ..., are included in the APF output currents other than the compensation harmonic currents, and furthermore, in the three-phase four-wire system, no extra zero-sequence harmonic currents exist in the neutral line. As a result, APF has the best compensation effect so that the least harmonic currents flow into the power system.