In several countries, during the grid faults, the large distributed generation (DG) is expected to support the voltage at the point of common coupling, as per the prevailing grid code. Large DGs are connected to a high voltage transmission line, where the voltage support is achieved by supplying the reactive power. The recent research trend, however, is toward voltage support by the medium size DGs that are connected to the resistive-inductive grid. The resistive-inductive grid requires both active and reactive power for voltage support. The existing voltage support schemes (VSS) for the resistive-inductive grid impose certain constraints on the proportion of active and reactive components of currents that adversely affect the performance. This article proposes a novel VSS that does not impose such constraints and provides enough compensation when available active power is not sufficient. It also provides the required compensation with much less active power curtailment when available active power is high. That is, the proposed scheme, in both cases, helps in achieving the same voltage compensation in spite of the nature of the injected current being significantly different. This feature is clearly demonstrated graphically using the vector diagram. The reference current expressions for the proposed VSS are analytically derived. The simulation and hardware results demonstrate that the proposed VSS achieves its objectives.

中文翻译：

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不平衡条件下分布式电源接入阻感电网的无约束电压支持方案


在一些国家，根据现行电网法规，在电网故障期间，大型分布式发电 (DG) 预计将支持公共耦合点的电压。大型DG连接到高压输电线路，通过提供无功功率来实现电压支持。然而，最近的研究趋势是通过连接到阻感电网的中型 DG 提供电压支持。阻感电网需要有功功率和无功功率来支持电压。现有的阻感电网电压支持方案（VSS）对电流的有功和无功分量的比例施加了一定的限制，这对性能产生不利影响。本文提出了一种新颖的 VSS，它不会施加此类约束，并在可用有功功率不足时提供足够的补偿。当可用有功功率较高时，它还能以更少的有功功率削减提供所需的补偿。也就是说，所提出的方案在两种情况下都有助于实现相同的电压补偿，尽管注入电流的性质显着不同。使用矢量图以图形方式清楚地演示了此功能。所提出的 VSS 的参考电流表达式是通过分析得出的。仿真和硬件结果表明所提出的 VSS 实现了其目标。