1.国网浙江温州供电有限责任公司;2.重庆大学电气工程学院
国网浙江省电力有限公司科技项目资助(5211WZ18007G);国家自然科学基金项目（51177177）
1.State Grid Zhejiang Wenzhou Power Supply Company;2.School of Electrical Engineering， Chongqing University
海岛易出现台风等极端天气，在极端自然条件下，容易造成海岛微电网运行故障，甚至导致海岛微电网全面崩溃。当海岛微电网全面崩溃时需要进行黑启动使整个系统恢复，但是由于海岛微电网负荷的特殊性，含有大量基于异步电动机的感性负荷在黑启动过程中会影响系统电压。为了提升海岛微电网黑启动的效率，本文提出一种基于虚拟有功负荷的海岛微电网黑启动优化策略。首先提出黑启动电源启动顺序优化模型，利用熵权法对不同DG的黑启动能力进行评价，并按照其评价值从高到低顺序分时步进行恢复DG；然后，提出每个时步负荷恢复优化模型，以负荷恢复量最大和负荷恢复重要程度最大作为目标并利用PSO算法求解出相应的负荷优化模型；接着，提出每个时步DG与负荷的路径恢复优化模型并利用最小生成树的Prim路径寻优算法进行求解。另外，本文还提出虚拟有功负荷构造方法，在黑启动过程中考虑将感性负荷与并联补偿电容一起等效为有功负荷，从而提高黑启动成功率。最后，采用简化的19节点微电网结构作为测试系统进行仿真验证，仿真结果表明，与没有考虑优化的黑启动策略相比，本文方法在黑启动过程中负荷恢复量提高了33.8%，同时考虑了恢复负荷的重要程度，并且，路径恢复总时间减少了55.1%，提高了海岛微电网黑启动的效率。此外，根据本文提出的虚拟有功负荷构造方法，仿真结果表明当并联电容提供的无功足够时，可以实现在黑启动过程中明显减小感性负荷对系统电压造成的影响。
Island is prone to extreme weather such as typhoons. Under extreme natural conditions, it is easy to cause the operation of the island’s microgrid to malfunction, and even cause the island’s microgrid to collapse. When the island microgrid collapses, the black start is required to restore the entire system. However, due to the particularity of the island microgrid load, a large number of inductive loads based on asynchronous motors will affect the system voltage during the black start. In order to improve the efficiency of black start of island microgrid, this paper proposes a black start optimization strategy of island microgrid based on virtual active load. First, propose a black start power startup sequence optimization model, use the entropy weight method to evaluate the black start ability of different DGs, and restore DGs in time steps according to their evaluation value from high to low; then, propose load recovery at each time step The optimization model takes the maximum load recovery amount and the maximum load recovery importance as the goal, and uses the PSO algorithm to solve the corresponding load optimization model; then, the path recovery optimization model of each time step DG and load is proposed and the Prim of the minimum spanning tree is used Path optimization algorithm to solve. In addition, this paper also proposes a virtual active load construction method. In the black start process, it is considered that the inductive load and the parallel compensation capacitor are equivalent to the active load, thereby improving the black start success rate. Finally, the simplified 19-node microgrid structure is used as the test system for simulation verification. The simulation results show that, compared with the black start strategy that does not consider optimization, the method in this paper increases the load recovery by 33.8% during the black start process. The importance of restoring the load, and the total path restoration time is reduced by 54.9%, which improves the efficiency of the black start of the island microgrid. In addition, according to the virtual active load construction method proposed in this paper, the simulation results show that when the reactive power provided by the parallel capacitor is sufficient, the impact of the inductive load on the system voltage can be significantly reduced during the black start process.
