高比例新能源接入电网的间歇性和波动性对系统稳定性有显著影响.因此,评估和提升含高比例可再生能源(Renewable Energy Source,RES)的配电网稳定性至关重要.文中提出了一种新的系统强度评估指标——集成短路比(Integrated Short Circuit Ratio,ISCR),该指标不仅考虑了RES之间的相互作用,还考虑了储能设备(Energy Storage Device,ESD)的影响,能更准确地辨识电网薄弱环节.另外,基于ISCR提出了通过双层优化方法调配RES和ESD的位置和容量的配电网稳定性提升方法,以增强系统强度并提高RES和ESD容量.在上层,对RES的位置和容量进行优化,确保节点处的ISCR值最大;在下层,对ESD的位置和容量进行优化,确保ISCR值高于临界短路比(Critical Short Circuit Ratio,CSCR),以保持系统强大.位置优化由节点处的ISCR值确定.容量优化采用线性规划方法求解.最后,案例研究验证了所提优化方法在保持系统强度的同时增加RES和ESD容量的有效性.
The Study on Assessing of Weak Links in the Stability of Distribution Networks with a High Proportion of New Energy Access and the Technology for Stabilizing and Regulating
The intermittency and volatility of high-proportion renewable energy access to the power grid have a significant impact on system stability. Therefore,it is crucial to evaluate and improve the stability of distribution networks with high proportions of renewable energy sources ( RES ) . This paper proposes a new power grid strength evaluation index,the integrated short circuit ratio ( ISCR),which not only considers the interaction between RES,but also considers the impact of energy storage devices ( ESD),and can more accurately identify weak links in the power grid.In addition,based on ISCR,a distribution network stability improvement method is proposed to allocate the location and capacity of RES and ESD through a two-level optimization method to enhance system strength and increase the capacity of RES and ESD.In the upper level,the location and capacity of RES are optimized to ensure the maximum ISCR value at the node.In the lower level,the location and capacity of ESD are optimized to ensure that the ISCR value is higher than the critical short circuit ratio (CSCR) to maintain system strength.The location optimization is determined by the ISCR value at the node. The capacity optimization is solved using linear programming methods. Finally,a case study verifies the effectiveness of the proposed optimization method in maintaining grid strength while increasing the capacity of RES and ESD.
integrated short circuit ratio ( ISCR)bi-level optimizationgrid strengthweak pointstabilization control
万方数据
维普
