分布式能源的渗透率不断提高给配电网带来更加复杂的电压质量及安全稳定问题,单一的无功或储能优化配置难以满足现代化电网日渐多元化的需求。提出一种储能与无功相结合的配置策略,用以满足新能源配电网在有功调节与无功补偿两方面的需求,实现灵活性、电压质量、经济性三方面的权衡优化,适应不同渗透率新能源的影响。首先,以灵活性需求、无功需求两方面为目标建立配电网安全稳定评价体系;其次,考虑规划层与运行层的耦合性,建立配电网储能-无功优化配置双层模型;之后,使用小概率随机突变法改进标准粒子群算法,减小计算过程中陷入局部最优的可能。最后,使用改进的IEEE 33节点配电系统进行仿真测试,验证所提方案的合理性、有效性。仿真结果表明,所提方案能够有效改善配电网的经济性与安全稳定,且在不同的新能源渗透率下均能得到多目标兼顾的最优配置方案。

Increasing the permeability of distributed energy results in a greater number of complex problems related to voltage quality, safety, and stability in distribution networks. Achieving a single optimal configuration of reactive power or energy storage to satisfy the increasingly diverse requirements of modern power grids is difficult. In this study, a configuration strategy that combines energy storage and reactive power is proposed to meet the requirements of new energy distribution networks in both active-power regulation and reactive-power compensation. The strategy also realizes a balanced optimization of flexibility, voltage quality, and economy, and adapts to the influence of new energy under different permeabilities. First, a safety and stability evaluation system of the distribution network is established based on flexibility and reactive-power demands. Second, based on the coupling between the planning and operating layers, a two-layer model of optimal energy-reactive power allocation in the distribution network is established. A small-probability random mutation method is then used to improve the standard particle swarm optimization algorithm to reduce the possibility of falling into local optima. Finally, an improved IEEE-33 node distribution system is used in a simulation test to verify the rationality and effectiveness of the scheme. Simulation results show that the proposed scheme can effectively improve the economy, security, and stability of the distribution network, and a multi-objective optimal configuration scheme can be obtained under new energy permeabilities.

火电灵活性改造作为“十三五”电力规划的亮点被提出,但“十三五”期间在各地的发展态势相异。从长久来看,火电作为我国发电容量主体,仍将在多数地区提供最主要的调节容量。为此,文章全面梳理了火电灵活性改造的国内外发展历程,总结了影响火电灵活性改造的关键技术、经济与机制要素,提出了国内开展的典型改造模式,并对我国火电灵活性改造的未来发展前景和重点研究问题进行了预测和分析。研究表明,随着各类灵活性市场的建立,我国火电灵活性改造将由政策主导向市场主导过渡,灵活性也将成为火电乃至整个电力系统从规划、设计到运行的核心指标,构建适应中国特色的火电灵活性改造技术标准与规划体系将为我国电力系统成功转型提供重要基石。

The flexibility retrofit of thermal power has been proposed as a highlight in the 13th Five-Year Power plan, but the development trend during the 13th Five-Year Plan period in different regions is diverse. In the long run, thermal power, as the main body of China’s power generation capacity, will still provide the most important regulation capacity in most regions. Thus, this article comprehensively sorts out the domestic and foreign development history of flexibility retrofit of thermal power, summarizes the key technical, economic, and mechanism factors that affect its progress, proposes typical flexibility retrofit models, and discusses its future development prospects and key research issues. The investigation shows that, with the establishment of various flexibility markets, flexibility retrofit of thermal power in China will transit from policy-oriented to market-oriented, and flexibility will also become the core indicator of thermal power and even the entire power system from plan, design to operation. It will be an important cornerstone of the successful transformation for China’s power system building the technical standards and planning system with Chinese characteristics for thermal-power flexibility retrofit.

大规模分布式电源（distributed generation，DG）接入电网给电力系统传统集中式调控带来困难。为进一步提升分布式电源集群（distributed generation cluster，DGC）灵活性分布式调控，提出一种考虑DGC供需平衡及响应速度的集群划分方法。首先进行了集群爬坡灵活性分析，提出了功率分配策略以满足调频灵活性需求；接着，提出了DGC供需平衡指标以及响应速度指标，得到了集群划分方法；最后，基于IEEE 33节点算例验证了所提方法的有效性。

The large-scale connection of distributed generation (DG) to the power grid brings about significant difficulties to the conventional centralized regulation of the power system. In order to improve the regulation flexibility of distributed generation cluster (DGC), a cluster partition method is proposed considering the supply-demand balance and response speed of DGC. Firstly, the cluster climbing flexibility is analyzed and a power allocation strategy is proposed to meet the demand of FM flexibility. Then, the DGC supply and demand balance index and response speed index are proposed, and the cluster partition method is obtained. Finally, an IEEE 33 node example is given to verify the effectiveness of the proposed method.

高比例分布式电源、电动汽车接入配电台区下,将面临着承载能力不足、负载率不均衡以及电压越限等问题,台区柔性互联是有效的解决方法之一。提出了一种考虑经济性和供电能力的台区柔性互联主从博弈规划模型,以经济性决策和供电能力决策为主、从体博弈者,共同参与规划决策过程。首先,建立了直流母线分段链式柔性互联结构下的台区潮流模型;然后建立了主从博弈规划模型,以互联方案和互联设备装机容量、年综合成本最小为主体博弈者的策略和支付,以台区所供负荷视在功率、N-0安全性下供电能力最大为从体博弈者的策略和支付,并计及台区运行潮流约束,再基于粒子群算法进行求解;最后通过台区接入高比例光伏发电的IEEE 33节点配电网进行算例分析,结果表明采用所提规划模型能均衡提升系统的运行经济性和供电能力。

A large proportion of distributed generation and electric vehicles are connected to distribution station areas. This results in several problems, such as insufficient hosting capacity, unbalanced load rates, and out-of-limit voltage. The flexible interconnection of the station areas is an effective solution to these problems. This paper proposes a master-slave game planning model for the flexible interconnection of distribution station areas, considering economic and power supply capacities. The proposed model considers economic decision-making as the main player and power supply capacity decision-making as the subordinate player, jointly participating in the planning decision-making process. First, a power flow model of the substation area is established using a DC bus-segmented chain flexible interconnection structure. Subsequently, a planning model based on a master-slave game is established. The interconnection schemes and installed capacity of the interconnected devices are used as the main player strategy, the minimum annual comprehensive cost is the payment. The load apparent power of the substation areas is used as the subordinate player strategy, and the maximum power-supply capacity under N-0 security constraints is the payment. The power-flow constraints of the substation areas operation are considered in the model. The particle swarm optimization algorithm is used to solve this problem. Finally, an IEEE-33 node distribution network connected to a high proportion of photovoltaic power generation in the substation area is analyzed. The results show that the proposed model can balance the operational economy and power supply capacity of the system.

低压用户侧大量分布式光伏和储能接入有利于可再生能源发电就地消纳,然而,低压用户与中压配电网分属不同利益主体,其相互之间的运行优化指标往往存在冲突。为此,提出一种高渗透率分布式光伏和储能接入的中低压配电网多目标分布式协调优化运行策略,考虑中低压配电网潮流约束,分别以配电网总成本及多台区负载率差异最小、低压配电网储能运行成本最小和光伏消纳率最大为目标,构建中、低压配电网优化模型,并采用熵权法对中低压配电网优化目标进行加权,建立中低压配电网协调优化模型;基于交替方向乘子法(alternating direction method of multipliers,ADMM),推导了求解协调优化模型的中、低压配电网迭代优化目标函数形式,设计了中、低压配电网协调优化策略,中压配电网通过影子价格迭代不断引导低压配电网用户调整分布式电源出力,仅通过少量边界信息交换实现中低压配电网多目标协调优化运行。最后,选取IEEE 33-7节点标准算例系统进行测试,证明了所提中低压配电网多目标分布式优化运行策略的有效性及可行性。

The access to substantial distributed photovoltaic and energy storage resources on the low-voltage user side is conducive to the local consumption of renewable energy power generation. However, low-voltage users and medium-voltage distribution networks are different stakeholders, and their operation optimization indicators often conflict with each other. Therefore, a multi-objective distributed coordinated optimization operation strategy for medium- and low-voltage distribution networks with high-permeability distributed photovoltaic and energy storage resource access is proposed. Considering the power flow constraints of the medium- and low-voltage distribution networks, an optimization model of the medium- and low-voltage distribution networks is established with the objectives of minimizing the total cost of the distribution network, load rate difference among multiple stations, and energy storage operation cost of the low-voltage distribution network and maximizing the photovoltaic absorption rate. The optimization objectives of the medium- and low-voltage distribution networks are weighted by the entropy weight method. Based on the alternating direction method of multipliers (ADMM), the objective function form of iterative optimization for medium- and low-voltage distribution networks is derived to solve the coordinated optimization model, and a coordinated optimization strategy for medium- and low-voltage distribution networks is designed. The medium-voltage distribution network continuously guides the users of low-voltage distribution networks to adjust the output of distributed power sources through shadow price iterations and realizes the multi-objective coordinated optimization operation of medium- and low-voltage distribution networks through a minimal exchange of boundary information. Finally, the effectiveness and feasibility of the proposed multi-objective distributed optimization operation strategy for medium- and low-voltage distribution networks is verified using the IEEE 33-7 node standard example system.