基于前推回代法的多供区互联配电网潮流计算

Power Flow Calculation of Interconnected Distribution Network with Multiple Supply Areas Based on Back/Forward Sweep Method

随着柔性多状态开关(SNOP)的出现和应用,现代配电网多电压等级、多平衡节点的供区互联运行模式将成为常态。这将使得配电网出现合环且多环运行,也使得在线优化调度运行成为可能,因此,对于多供区多馈线互联的大规模配电网的潮流计算方法提出了新的需求。文中通过将实际工程中采用SNOP互联合环运行的大规模多平衡节点配电网络,依据每个平衡节点所辐射区域对多环进行拆解,进而实现对配电网的分块处理,然后基于广度优先搜索算法对节点进行分区分层编号,同时,采用改进的前推回代法,针对SNOP的PV运行模式,通过无功分摊法预估PV节点的无功功率初值,再由功率相加法得到PV节点的无功功率变化量,将其转化为前推回代法可处理的PQ节点。最后,通过某地实际396节点配电网的潮流计算结果表明所提方法有效且快速。

With the emergence and application of the soft normally open point(SNOP), the operation mode of supply area interconnection of multiple voltage levels and multiple balance nodes will become the normal state in the modern distribution network, which make the operation of integrated ring and multiple rings in distribution network and online optimization scheduling operation possible. Therefore, new requirements are put forward for the power flow calculation method of large-scale distribution network with multiple supply areas and multi-feeder interconnection. In view of this, this paper dismantles multiple rings shaped by SNOP in a large-scale multi-balance bus distribution network in actual engineering project, according to the radiated area of each balance bus. Therefore, the network can be divided into several blocks. The breadth-first search algorithm performs hierarchical layering of buses, and adopts an improved back/forward sweep method. For the PV operation mode of SNOP, the reactive power initial value of the PV bus is estimated by the reactive power sharing method, and then the power addition method is used to obtain the variation of the reactive power. The reactive power addition method converts a PV bus into a PQ bus that can be processed by the back/forward sweep method. Finally, the power flow calculation results of the actual 396-bus distribution network in a certain place show that the adopted method is effective and fast.