【作者】 张健；

【导师】 薛禹胜；

【作者基本信息】 山东大学 ， 电气工程， 2025， 硕士

【摘要】 随着高比例可再生能源并网和大容量高压直流输电(high-voltage direct current,HVDC)工程的广泛应用,电力系统的运行特性发生了深刻变革。新能源机组渗透率的持续提升导致系统等效惯量和调频能力明显降低,同时系统运行的不确定性和波动性显著增强。在此背景下,短路故障等大功率缺额扰动引发的电网频率严重偏移甚至失稳的风险显著上升。紧急控制(emergency control,EC)作为保障电力系统安全稳定运行的重要手段,通过快速调整控制措施有效抑制频率和电压波动,避免系统失稳。然而,随着同步机组出力占比的下降和新型电力系统去中心化特征的凸显,传统紧急控制措施支撑能力逐步减弱。与此同时,光伏机组、储能系统(energy storage system,ESS)等新型资源凭借电力电子设备的快速调节特性,展现出巨大的调节潜力。因此,协调控制各类可控资源并将其纳入电力系统安全稳定控制体系,不仅能够提供有别于传统切负荷的新型控制手段,还能提升紧急控制的精细化水平,对保障电力系统稳定运行具有重要意义。本文围绕多类可控资源协调参与的电网紧急控制策略展开研究,主要从以下三个方面进行深入探讨:可控资源参与紧急控制的暂态特性及影响因素分析、多类可控资源的协调控制策略以及配网有源化场景下的主配分层协同控制策略。具体研究内容如下:(1)针对高比例可再生能源并网对系统暂态稳定性的影响,建立了光伏、储能等可控资源的动态响应模型,深入研究了其在频率稳定控制中的暂态特性及影响因素。系统分析了高比例光伏与风电并网对系统暂态稳定性的影响机制,明确了各类资源的参与方式和作用机理。重点研究了风光机组在频率控制中的可控性及其约束条件,揭示了储能系统在频率安全紧急控制中改善频率特性的机理。通过仿真结果,以光伏、储能为例验证了将可控资源纳入稳定控制体系对提升系统频率稳定的有效性。(2)针对传统控制策略在高比例可再生能源场景下的局限性,提出了一种基于多类可控资源协调出力的紧急控制策略。结合各类可控资源的技术特性和紧急控制需求,分别设计了光伏和储能的紧急出力支撑控制策略。提出基于光伏储备系数和储能功率快速调节的协调控制策略,实现了多类可控资源的优化整合。采用改进的带精英保留遗传算法(non-dominated sorting genetic algorithm-Ⅱ,NSGA-Ⅱ)进行多目标优化求解,获得兼顾经济性与安全性的最优控制方案。仿真结果验证了可控资源灵活出力与紧急切负荷协同控制的有效性。(3)针对高比例分布式能源(distributed energy resources,DERs)接入配电网带来的稳定性挑战,提出了一种考虑多类可控资源协调的主配分层紧急控制策略。通过深入分析分布式能源配网侧并网对系统暂态稳定性的影响机理,揭示了配网有源化引发的功率双向流动及紧急控制复杂化等问题。提出了配网关键权重与节点电压裕度的精细化分层控制方法:主网侧根据权重分配控制量,配网侧优化分布式资源出力并实施精细化切负荷策略,有效避免了分布式机组的误切除。在此基础上构建了集成多类可控资源的主配分层协同控制框架,通过优化控制决策实现系统稳定性的最小代价控制,仿真结果验证了所提策略的优越性能。更多还原

【Abstract】 With the widespread integration of high-penetration renewable energy and large-scale high-voltage direct current(HVDC)transmission projects,the operational characteristics of power systems have undergone profound transformations.The continuous increase in renewable energy penetration has significantly reduced the system’s equivalent inertia and frequency regulation capability while exacerbating operational uncertainty and volatility.Against this backdrop,the risk of severe frequency deviations and even instability caused by large power deficits,such as short-circuit faults,has markedly increased.As a critical measure to ensure the secure and stable operation of power systems,emergency control(EC)effectively suppresses frequency and voltage fluctuations and prevents system instability through rapid control actions.However,as the proportion of synchronous generation decreases and the decentralization trend of modern power systems intensifies,the support capacity of traditional emergency control measures is gradually weakening.Meanwhile,new resources such as photovoltaic(PV)units and energy storage systems(ESS)exhibit substantial regulation potential due to their fast response characteristics enabled by power electronic interfaces.Therefore,incorporating multiple controllable resources into the security and stability control framework of power systems not only introduces novel control methods beyond conventional load shedding but also enhances the precision of emergency control,playing a crucial role in maintaining stable power system operation.This paper investigates emergency control strategies involving the coordinated participation of multiple controllable resources,focusing on three key aspects:transient characteristics and influencing factors of controllable resources in emergency control,coordinated control strategies for multiple controllable resources,and hierarchical transmission-distribution collaborative control strategies under active distribution network scenarios.The main research contents are as follows:(1)Aiming at the impact of high proportion of renewable energy grid-connectedness on the transient stability of the system,the dynamic response models of photovoltaic,energy storage and other controllable resources are established,and their transient characteristics and influencing factors in the frequency stability control are studied in depth.The mechanism of the influence of the high proportion of PV and wind power grid-connected on the transient stability of the system is systematically analysed,and the mode of participation and mechanism of the various types of resources are clarified.Focusing on the controllability of wind turbines in frequency control and their constraints,the mechanism of energy storage system to improve the frequency characteristics in frequency safety emergency control is revealed.Through simulation results,the effectiveness of incorporating controllable resources into the stabilisation control system to improve the frequency stability of the system is verified by taking photovoltaic and energy storage as examples.(2)Aiming at the limitations of the traditional control strategy in the high proportion of renewable energy scenarios,an emergency control strategy based on the coordinated output of multiple types of controllable resources is proposed.Combining the technical characteristics and emergency control needs of various types of controllable resources,the emergency power support control strategies for PV and energy storage are designed respectively.A coordinated control strategy based on the rapid adjustment of PV reserve factor and energy storage power is proposed to achieve the optimal integration of multiple types of controllable resources.The improved non-dominated sorting genetic algorithm-Ⅱ(NSGA-Ⅱ)is used for multi-objective optimal solution to obtain the optimal control scheme that combines economy and safety.The simulation results verify the effectiveness of the flexible output of controllable resources and the cooperative control of emergency load cutting.(3)Aiming at the stability challenges posed by the high proportion of distributed energy resources(DERs)connected to the distribution network,a main-distribution hierarchical emergency control strategy considering the coordination of multiple types of controllable resources is proposed.Through in-depth analysis of the impact mechanism of distributed energy resources’ grid integration on system transient stability,the problems of bidirectional power flow and emergency control complexity triggered by the active distribution network are revealed.A refined hierarchical control method of distribution network with key weights and node voltage margins is proposed:the main network side allocates the control quantity according to the weights,and the distribution network side optimises the distributed resource output and implements a refined load-shedding strategy,which effectively avoids erroneous resection of distributed units.On this basis,a hierarchical cooperative control framework integrating multiple types of controllable resources is constructed to achieve the least-cost control of system stability through optimal control decisions,and the simulation results verify the superior performance of the proposed strategy.更多还原