Comparisons Between the p--q and p--q--r Theories in Three-Phase Four-Wire Systems
Comparisons Between the p--q and p--q--r Theories in Three-Phase Four-Wire Systems
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DOI：
10.1109/tpel.2008.2008187
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发表时间：
2009-01
影响因子：
6.7
通讯作者：
M. Aredes;Hirofumi Akagi;Edson H. Watanabe;Eumir Vergara Salgado;L. Encarnação
中科院分区：
文献类型：
--
作者：
M. Aredes;Hirofumi Akagi;Edson H. Watanabe;Eumir Vergara Salgado;L. Encarnação
本文比较分析了p-q和p-q-r理论在三相四线制并联有源电力滤波器中的应用结果，讨论了计算补偿电流的控制方法中系统电压的影响。结果表明，在某些情况下，如果目标是获得正弦补偿电流，则需要对系统电压进行预处理。另一方面，当目标是补偿零序电流时，讨论了有源滤波器中储能元件的需求。在这种情况下，如果零序分量同时存在于系统电压和负载电流中，它们就会产生零序潮流，基于这两种理论的控制方法必须包含额外的计算，以允许消除有源滤波器中的储能元件。提出了一种基于p-q理论的控制策略，可以在不需要储能元件的情况下消除中性点电流，避免了p-q-r理论中需要从字母表a0到pqr坐标的额外转换。为了比较两种控制方法的性能，给出了仿真结果。
This paper presents a comparative analysis between results from applications of the p-q and the p-q-r theories in shunt active power filters for three-phase four-wire systems, discussing aspects related to the influence of the system voltage in the control methods that calculate the compensating currents. It is shown that in some cases, a preprocessing of the system voltage is required if the goal is to achieve sinusoidal compensated currents. On the other hand, when the goal is to compensate zero-sequence current, the need of energy storage elements in the active filter is discussed. In this case, if zero-sequence components are present simultaneously in the system voltage and load current, they produce zero-sequence power flow, and the control methods based on both theories must contain additional calculations to allow the elimination of energy storage elements in the active filter. A control strategy based on the p-q theory is proposed to eliminate the neutral current without the need of energy storage elements, with the advantage of avoiding the extra transformation from alphabeta0 to pqr coordinates that is needed in the p-q-r theory. Simulation results are presented for the purpose of comparing the performance of both control methods.