The effects of distribution-connected solar farms on the transmission and distribution systems are studied in this paper using a practical power system network. Both the transmission and distribution networks are modeled and co-simulated for intermittent effects of solar power and changing load profiles. These effects include flicker in both the transmission and the distribution systems, operation of the substation Load Tap Changer (LTC) and feeder regulators, and distribution feeder voltage profiles. The results of the study show a potential hunting effect causing excessive LTC operation especially during periods of high reverse power flow condition and a significant visible flicker in the distribution system but lower levels of flicker at the transmission level. It is shown that the hunting behavior of the LTC can be mitigated and downstream feeder voltage profiles can be improved via enhanced bandwidth, block operation mode, and adjusting time delay of the substation LTC controller. In addition, the inverter Volt-Var control can be used to effectively diminish excessive LTC operation based on IEEE Std 1547-2018 Volt-Var characteristics with modified settings. Finally, an enhanced load-flow algorithm with modified Jacobian is presented that incorporates the Distributed Energy Resource (DER) Volt-Var characteristics in the conventional Newton-Raphson method.

中文翻译：

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DER单元存在下输配电系统的相互作用-联合仿真方法

本文通过一个实用的电力系统网络研究了分布式太阳能电站对输配电系统的影响。输电和配电网络均经过建模和共同仿真，以实现太阳能的间歇性影响和不断变化的负荷曲线。这些影响包括传输和配电系统中的闪烁，变电站负荷分接开关（LTC）和馈线调节器的运行以及配电馈线电压曲线。研究结果表明，潜在的振荡效应会导致过多的LTC操作，尤其是在高反向功率流条件期间，以及配电系统中明显的可见闪烁，而在传输级别的闪烁水平较低时。结果表明，可以通过增强带宽，块操作模式和调整变电站LTC控制器的延迟来减轻LTC的振荡行为，并改善下游馈线电压分布。此外，基于带有修改设置的IEEE Std 1547-2018 Volt-Var特性，逆变器Volt-Var控制可用于有效减少过多的LTC操作。最后，提出了一种改进的改进雅可比潮流算法，该算法结合了传统牛顿-拉夫森方法中的分布式能源伏特-瓦尔特性。逆变器的Volt-Var控制可用于根据IEEE Std 1547-2018 Volt-Var特性和修改后的设置有效地减少过多的LTC操作。最后，提出了一种改进的改进雅可比潮流算法，该算法结合了传统牛顿-拉夫森方法中的分布式能源伏特-瓦尔特性。逆变器的Volt-Var控制可用于根据IEEE Std 1547-2018 Volt-Var特性和修改后的设置有效地减少过多的LTC操作。最后，提出了一种改进的改进雅可比潮流算法，该算法结合了传统牛顿-拉夫森方法中的分布式能源伏特-瓦尔特性。