Dynamic grid support in low voltage grids — fault ride-through and reactive power/voltage support during grid disturbances
Dynamic grid support in low voltage grids — fault ride-through and reactive power/voltage support during grid disturbances
复制标题
低压电网中的动态电网支持——电网扰动期间的故障穿越和无功功率/电压支持
DOI：
10.1109/pscc.2014.7038468
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发表时间：
2014
期刊：
影响因子：
--
通讯作者：
M. Braun
中科院分区：
文献类型：
--
作者：
G. Lammert;Tobias Heß;M. Schmidt;P. Schegner;M. Braun
中、高压电网中的故障导致低电压等级的电压暂降。由于电压骤降，分布式发电机从低压电网断开。根据断开发电的数量，系统稳定性可能会受到影响。通过动态电网支持，分布式发电机在故障期间保持连接到电网，也称为故障穿越。此外，无功功率的馈入支持故障期间的电压。根据现有技术，不存在对低压电网中的动态电网支持的要求。然而，随着分布式发电的高度渗透，这些要求可能会在未来发生变化。研究了低压电网中的动网支撑问题。采用IEEE/CIGRE基准模型研究了中低压电网动态支撑对配电网的影响。逆变器，直接耦合的同步和感应发电机的模型实现。此外，现在和未来的保护系统故障穿越能力被添加到电网模型。逆变器配备无功电流控制器，在故障期间提供电压支持。为了确定动态电网支持的效果，对有和没有动态电网支持的高压和中压电网中的故障进行了仿真和评估。结果表明，通过动态电网支持进行电压提升以恢复电压的效果是微不足道的。然而，随着分布式发电机的高渗透水平，电压提升增加，故障的影响可以进一步受到限制。这项调查表明，在低压电网中的动态电网支持，以避免大量的功率损失，并提高电压恢复的潜力。
Faults in medium and high voltage grids lead to voltage sags in the low voltage level. Due to the voltage dip, distributed generators disconnect from the low voltage grid. Depending on the amount of disconnected generation, system stability could be compromised. With a dynamic grid support, distributed generators remain connected to the grid during faults, also called fault ride-through. Moreover, the feed in of reactive power supports the voltage during the fault. According to the present state of the art, no requirements exist for a dynamic grid support in low voltage grids. However, with a high penetration of distributed generation these requirements might change in the future. This paper investigates the dynamic grid support in low voltage grids. The impact of a dynamic grid support on a distribution grid is studied with IEEE/CIGRE benchmark models for low and medium voltage grids. Models of inverters, directly-coupled synchronous and induction generators are implemented. Furthermore, a present and a future protection system with fault ride-through capability are added to the grid models. The inverters are equipped with a reactive current controller to give a voltage support during faults. To determine the effect of a dynamic grid support, faults in high and medium voltage grids with and without dynamic grid support are simulated and evaluated. The results have shown that the effect of the voltage boost through dynamic grid support in order to recover the voltage is marginal. However, with a high penetration level of distributed generators the voltage boost increases and the impact of faults can be further limited. This investigation has demonstrated the potential of dynamic grid support in low voltage grids to avoid the loss of a large amount of power and to improve the voltage recovery.