考虑电网支撑能力约束的煤电退役与调相机配置协调策略

为了尽可能减少煤电机组退役和大规模非同步电源馈入对受端电网安全稳定运行的影响，本文在兼顾电网支撑能力约束的基础上提出了煤电退役与调相机配置协调策略。首先，构建了煤电机组对直流落点的无功支撑系数指标，并综合考虑机组役龄、污染物排放量、煤耗率等常规因素确定受端电网煤电机组的退役优先级顺序。进而，基于预想故障下系统的最大频率变化率和极值频率偏差约束得到煤电机组可退役的最大容量，形成相应的煤电机组退役策略。然后，提出了基于二分法的同步调相机配置策略，该策略可以对投建调相机的容量和选址进行决策，通过在煤电退役路径中协调配置调相机，确保受端电网的电压支撑能力满足要求。最后，在受端电网配置调相机后，对煤电机组可退役的最大容量进行同步更新，并对煤电机组退役策略进行相应的调整，实现煤电机组退役和调相机配置的相互协调。基于改进的IEEE 39节点系统和河南电网规划系统开展了仿真分析，根据多馈入短路比和预想故障下的暂态仿真结果可知，在煤电机组退役容量相同的情况下，与传统的煤电机组退役策略相比，本文所提策略确定的煤电机组退役顺序可以有效降低机组退役对受端电网静态电压稳定性的影响，并且可以降低大扰动故障下对受端电网暂态电压稳定性的影响。

Coordination Strategy of Coal-fired Units Decommissioning and Condenser Configuration Considering the Support Capability Constraints of Power Systems

In order to minimize the impact of coal-fired units (CFUs) decommissioning and large-scale non-synchronous generation installation on the secure and stable operation of receiving-end grids, a coordinated strategy for the decommissioning of CFUs and the configuration of synchronous condensers (SynCons) considering the support capability of power systems was proposed in this paper. Firstly, the index of the DC reactive power support factor was established, the decommissioning priority order of CFUs in the receiving-end grid was determined by the service life, the pollutant emissions, the coal consumption rate, and other general factors. Secondly, the maximum decommissioning capacity of CFUs was calculated by the post-contingency maximum rate-of-change of frequency and the frequency nadir constraints. Thus, the corresponding decommissioning strategy for CFUs has been formed. Then, a configuration strategy of SynCons based on the bisection algorithm was proposed to meet the voltage support capacity requirements of the receiving-end grid with the decommissioning of CFUs, which can achieve the optimal configuration capacity and location of SynCons. Finally, after the configuration strategy of SynCons was set, the maximum decommissioning capacity of CFUs was updated synchronously. The decommissioning strategy of CFUs was adjusted, so as to realize the mutual coordination between the decommissioning strategy of CFUs and the configuration strategy of SynCons. Simulations on a modified IEEE 39 system and the power system in Henan province were conducted to verify the effectiveness of the proposed coordinated strategy. According to the transient simulation results under multi-infeed short-circuit ratios and faults, the obtained results determined by the proposed strategy can effectively reduce the influence of CFUs decommissioning on the static voltage stability of the power system under the same decommissioning capacity. Furthermore, the transient simulation results also show that the proposed strategy can reduce the influence of large disturbances on the transient voltage stability of the receiving-end grid.