基于SFR模型的电网广义惯性分区评估方法研究

Research on generalized inertial partition evaluation methodof power grid based on SFR model

近年来新型电力系统的电力电子化趋势愈发明显,一方面随着能源结构的调整,大量采用电力电子接口的新能源发电接入电网;另一方面随着节能技术的发展,负荷设备也逐步实现了电力电子化.由于电网中的电力电子设备占例不断提高,削弱了原有同步发电机、异步电动机的占比,给电网的安全稳定运行造成了不利影响.基于SFR模型提出了一种电力系统广义惯性的分区模型及其评估方法,并可用于分区补偿前后的性能对比.首先,面向电力电子化趋势建立了电网的SFR广义惯性分区模型;其次,根据仿真算例分别模拟惯性补偿前后的系统分区频率曲线,通过粒子群优化算法拟合惯性时间常数H,并计算相应的惯性分布均匀指数Dδ;再次,通过综合评估H和Dδ,分析惯性大小的改善及惯性分布均匀性;最后,基于评估结果进一步调整补偿措施,返回上述参数计算步骤直至满足设计评估要求.通过仿真算例验证了相关模型及相应评估方法的正确性与适用性.

In recent years,the electronics dominated trend of power system is more obvious.On the one hand,with the adjustment of energy structure,a large number of new energy generation using power electronics interface is connected to the grid;on the other hand,with the development of energy-saving technology,load equipment has gradually become electronics dominated.However,due to the increasing proportion of power electronic equipment in the power grid,the capacity of the original synchronous generator and asynchronous motor has been weakened,and the safety and stability of power grid has been adversely affected.Therefore,based on SFR model,a partitioned evaluation method of generalized inertia of power systems is proposed in this paper,which will also be used to compare and evaluate the performance of the system before and after compensation.Firstly,a SFR generalized inertia partition model for the power grid is established to align with the trend of power electronics.Subsequently,simulation scenarios are employed to model the frequency curves of system partitions both before and after inertia compensation.The inertia time constant H is accurately determined through the application of a particle swarm optimization algorithm,and the corresponding inertia distribution uniformity index Dδis calculated.A comprehensive evaluation of H and Dδis then conducted,shedding light on the enhancement of inertia magnitude and the uniformity of inertia distribution.Finally,based on the evaluation results,compensation measures are further refined,the aforementioned parameter calculation steps are revisited until meeting the requirements of design evaluation.The correctness and applicability of the proposed models and corresponding evaluation methods are validated by simulation examples.