Equivalent Method of Integrated Power Generation System of Wind, Photovoltaic and Energy Storage in Power Flow Calculation and Transient Simulation

针对工程实际开展风光储联合发电系统在潮流计算和机电暂态仿真中的等值方法研究，旨在为大容量风光储联合发电系统的并网仿真分析奠定基础。将潮流计算的等值分为单元机组和集电系统2部分来研究。单元机组等值采用根据不同控制模式选取不同节点类型的方法，针对集电系统等值提出基于损耗不变原则的方法。等值模型和详细模型的算例结果表明，潮流计算等值方法具有较好的精度。在机电暂态仿真动态等值中，基于实际工程计算的最严重工况分析原则，提出运行在满出力点的单机“倍乘”等值模型，为工程计算中的风光储联合发电系统动态等值提供了一种解决方案。

Composition Modeling and Equivalence of an Integrated Power Generation System of Wind, Photovoltaic and Energy Storage Unit

利用间接组合建模的方法,在建立典型的双馈风机、光伏发电单元和储能单元的装置级机电暂态模型基础上,采用等值方法建立三者电站级的机电暂态模型,最终通过组合建模得到了风光储联合发电系统的机电暂态模型。在大型电力系统分析软件包的PSD-BPA暂态稳定程序中实现了风光储联合发电系统的仿真功能,通过典型算例和张北＂国家风光储输示范工程＂的仿真分析验证了模型的正确性,为风光储联合发电系统的并网研究提供了分析手段。

Optimal configuration for photovoltaic storage system capacity in 5G base station microgrids

Base station operators deploy a large number of distributed photovoltaics to solve the problems of high energy consumption and high electricity costs of 5G base stations.In this study,the idle space of the base station’s energy storage is used to stabilize the photovoltaic output,and a photovoltaic storage system microgrid of a 5G base station is constructed.Aiming at the capacity planning problem of photovoltaic storage systems,a two-layer optimal configuration method is proposed.The inner layer optimization considers the energy sharing among the base station microgrids,combines the communication characteristics of the 5G base station and the backup power demand of the energy storage battery,and determines an economic scheduling strategy for each photovoltaic storage system with the goal of minimizing the daily operation cost of the base station microgrid.The outer model aims to minimize the annual average comprehensive revenue of the 5G base station microgrid,while considering peak clipping and valley filling,to optimize the photovoltaic storage system capacity.The CPLEX solver and a genetic algorithm were used to solve the two-layer models.Considering the construction of the 5G base station in a certain area as an example,the results showed that the proposed model can not only reduce the cost of the 5G base station operators,but also reduce the peak load of the power grid and promote the local digestion of photovoltaic power.

Reliability Assessment Considering the Coordination of Wind Power, Solar Energy and Energy Storage

风光储联合发电系统并网后必须采取策略与系统之间实现协调调度与运行才可在保证可靠性的前提下最大化利用可再生能源，但现有的可靠性评估中还缺少对大规模风光储联合发电系统协调运行的考虑。针对此问题，基于序贯蒙特卡罗仿真方法，建立了风电、光伏和储能系统的发电可靠性评估模型，并提出了新的协调调度策略。模型综合考虑了风速、太阳光辐照度、环境温度以及2种新能源发电技术的能量变换特性和储能系统的充放电约束等因素。这些模型被应用到IEEERTS79中，通过在Matlab中编制程序进行仿真计算，考察不同的协调运行策略、联合发电系统容量配置以及储能特性对于系统裕度的影响。评估结果可为联合发电系统并网规划与设计提供参考。

Pumped hydro energy storage and 100 % renewable electricity for East Asia

Rapid cost reductions have led to the widespread deployment of renewable technologies such as solar photovoltaics(PV)and wind globally.Additional storage is needed when the share of solar PV and wind in electricity production rises to 50–100%.Pumped hydro energy storage constitutes 97%of the global capacity of stored power and over 99%of stored energy and is the leading method of energy storage.Off-river pumped hydro energy storage options,strong interconnections over large areas,and demand management can support a highly renewable electricity system at a modest cost.East Asia has abundant wind,solar,and off-river pumped hydro energy resources.The identified pumped hydro energy storage potential is 100 times more than required to support 100%renewable energy in East Asia.

Convexification Technique for Optimal Thermal-Wind-Photovoltaic Coordination Dispatch Incorporating an Energy Storage System

This paper proposes a solution to implementing acoordinated optimal day-ahead dispatch in a hybrid thermalwind-photovoltaic power system incorporating an energy storagesystem (ESS). Our aim is to minimize total generation costand restrain the frequent change of ESS charging/dischargingstatus while meeting a series of system operating constraints,including a proposed coordinated dispatch strategy for thepurpose of reducing thermal power fluctuations. A novel twostage convexification technique (TSCT) is designed and leveragedto convert the original non-convex optimal day-ahead dispatchmodel, without taking into account the constraints of the proposed coordinated dispatch strategy into two convex quadraticprogramming problems. When introducing the constraint ofthe coordinated dispatch strategy, the corresponding inequalityconstraints are transformed into a series of linear equalityconstraints, after which the original optimal day-ahead dispatchmodel can be solved by the TSCT mentioned above. Finally,numerical simulations and comparative analysis are performedon the IEEE standard test systems to verify the validity andeffectiveness of the proposed model and method.

Modelling and Coordinated Control of Grid Connected Photovoltaic,Wind Turbine Driven PMSG,and Energy Storage Device for a Hybrid DC/AC Microgrid

In a DC/AC microgrid system,the issues of DC bus voltage regulation and power sharing have been the subject of a significant amount of research.Integra-tion of renewable energy into the grid involves multiple converters and these are vulnerable to perturbations caused by transient events.To enhance the flexibility and controllability of the grid connected converter(GCC),this paper proposes a common DC bus voltage maintenance and power sharing control strategy of a GCC for a DC/AC microgrid.A maximum power point tracking algorithm is employed to enhance the power delivered by the wind turbine and photovoltaic module.The proposed control strategy consists of primary and secondary as-pects.In the primary layer control,the DC bus voltage is regulated by the GCC.In the secondary layer,the DC bus voltage is maintained by the energy storage device.This ensures reliable power for local loads during grid failures,while power injection to the grid is controlled by an en-ergy management algorithm followed by reference gen-eration of inductor current in the GCC.The proposed control strategy operates in different modes of DC voltage regulation,power injection to the grid and a hybrid op-erating mode.It provides wide flexible control and en-sures the reliable operation of the microgrid.The pro-posed and conventional techniques are compared for a 15.8 kW DC/AC microgrid system using the MATLAB/Simulink environment.The simulation results demonstrate the transient behaviour of the system in different operating conditions.The proposed control technique is twice as fast in its transient response and produces less oscillation than the conventional system.Index Terms—Wind energy,photovoltaic energy,DC/AC microgrid,battery energy storage system,co-ordinated control.

Test Facility for Low Potential Pumped Storage Power Plants and Hydrokinetic Turbines

The electric energy which is generated by wind power plants depends on the wind speed and exceeds with strong permissible wind speed the electric energy requirements of the country. In order not to reduce this electrical energy, it must be stored. The sensible energy storage is currently the pumped storage power plants. As the mountain ranges for conventional pumped storage power plants with drop heights of H 〉 600 m are strictly limited, the development of low potential pumped storage power plants has begun. Increasing the capacity of pumped storage power plants with regard to the wind power plants is urgently needed. In this paper, it is shown using the example of an unneeded port facility, how a port facility can be used after low conversion as a test facility for low potential pumped storage power plants and at the same time for the testing of hydro-kinetic turbines. This type of pump storage power plants does not save the energy due to large drop heights, but primarily due to the large volume flow of water.

Application of Power Electronics Converters in Renewable Energy

Against the backdrop of global energy shortages and increasingly severe environmental pollution,renewable energy is gradually becoming a significant direction for future energy development.Power electronics converters,as the core technology for energy conversion and control,play a crucial role in enhancing the efficiency and stability of renewable energy systems.This paper explores the basic principles and functions of power electronics converters and their specific applications in photovoltaic power generation,wind power generation,and energy storage systems.Additionally,it analyzes the current innovations in high-efficiency energy conversion,multilevel conversion technology,and the application of new materials and devices.By studying these technologies,the aim is to promote the widespread application of power electronics converters in renewable energy systems and provide theoretical and technical support for achieving sustainable energy development.

Optimal Sizing of Solar/Wind Hybrid Off-Grid Microgrids Using an Enhanced Genetic Algorithm

This paper presents a method for optimal sizing of an off-grid hybrid microgrid (MG) system in order to achieve a certain load demand. The hybrid MG is made of a solar photovoltaic (PV) system, wind turbine (TW) and energy storage system (ESS). The reliability of the MG system is modeled based on the loss of power supply probability (SPSP). For optimization, an enhanced Genetic Algorithm (GA) is used to minimize the total cost of the system over a 20-year period, while satisfying some reliability and operation constraints. A case study addressing optimal sizing of an off-grid hybrid microgrid in Nigeria is discussed. The result is compared with results obtained from the Brute Force and standard GA methods.

新能源场站快速有功控制及频率支撑技术综述

以光伏/风电为代表的新能源高比例并网降低了电力系统的惯量水平和频率支撑能力,频率稳定问题成为当前电网安全稳定和新能源高效消纳的核心问题之一。发展新能源发电并网机组单元和场站的快速有功频率响应和主动支撑能力是当前的研究热点。该文以“单机快速有功控制-场站快速有功控制-场站快速频率支撑”为主线,梳理光伏/风电的快速有功控制及频率支撑发展现状,分析频率检测、通信延时和控制响应模式等因素对光伏/风电场站频率响应快速性的影响,指出风电机组的机械载荷约束、风电场百毫秒级有功控制、场站的调频响应模式选择和优化、暂态有功无功协同控制是提升新能源发电单元和场站的快速有功频率响应能力的4个关键问题,最后对未来的重点研究方向进行展望和讨论。

海上油气平台不稳定电源与储能联合配置优化策略

针对海上油气平台集群接入不稳定电源与储能的联合配置问题,结合海上风电、光伏特点及已有的拓扑结构,提出了三阶段风机/光伏/储能阶段式联合配置策略,介绍嵌入潮流计算的阶段式粒子群算法。第一阶段通过LightGBM网络预测模型得到风机光伏的时序预测发电功率,再以投资建设经济性和潮流稳定性为目标优化每个节点的风机/光伏容量;第二阶段针对不稳定电源配置后的配电网,提出了基于电压和损耗灵敏度为指标的集群划分方法,将配电网集群划分为若干个子集群;第三阶段根据划分后的子集群,以储能容量、配电网损耗和节点电压波动为目标为每个子集群内配置储能。以渤海油田某10 kV实际油气平台配电网为例,设立燃气机出力功率自定义和经济性自定义两种方案来验证联合配置优化决策的合理性。结果表明,两种配置策略都可以有效地提升海上油气平台配电网的潮流稳定性,提高新能源的渗透率。本文研究验证了海上分散式风机/光伏发电工程的可行性,有利于实现未来海上油气平台的“零碳”建设。

基于分布鲁棒联合机会约束的光储充电站滚动优化调控模型

随着电动汽车的普及和清洁能源装机容量的日益增加,光储充电站展现出广阔的应用前景。针对电动汽车随机接入影响下光储充电站功率难以精准调控的问题,提出基于分布鲁棒联合机会约束(DRJCC)的光储充电站滚动优化调控模型。将基于混合整数规划(MIP)的精确DRJCC模型、基于CVaR-Slim凸松弛的DRJCC模型、基于Bonferroni不等式的DRJCC模型进行对比,通过算例分析验证了所提优化调控模型的有效性。算例分析表明,所提基于CVaR-Slim凸松弛的DRJCC模型能够同时满足更多电动汽车的充电需求。

提升光储充电站运行效率的多目标优化配置策略

光储充电站的运行效率直接影响到其经济效益及电网侧的电能质量。针对在进行容量配置时对运行效率考虑不足会导致非必要的电能损耗,文中提出一种提升光储充电站运行效率的多目标优化配置策略。通过分析光储充电站变换器与内源线路功率损耗对于运行效率的影响,提出充电站的运行效率评估指标与计算方法,并讨论光储充电站运行效率对其容量配置的影响。建立以充电站经济效益、运行效率、电网侧峰谷供电功率补偿能力最佳为优化目标的多目标容量优化配置策略。针对优化目标特性,提出一种改进二代非支配排序遗传算法得到优化策略求解方法。选取中国西南地区某典型光储充电站运营场景,通过算例验证了优化策略的有效性与优越性。

基于超导磁储能的光伏场站送出线路距离保护

受光伏逆变器控制策略影响,光伏场站呈弱馈性和电流相位受控特性,导致送出线路光伏侧距离保护的测量阻抗无法正确反映故障所在位置,抗过渡电阻能力大大下降。根据送出线路系统的故障分量序网图推导出线路短路阻抗的求解方程组,同时基于光伏场站直流母线接入的超导磁储能(superconducting magnetic energy storage,SMES)改变传统的低电压穿越控制策略,通过控保协同消除方程组中的未知量,进而对线路短路阻抗进行求解,提出了基于超导磁储能的光伏场站送出线路距离保护方案。与现有推导线路短路阻抗的方法相比,该方法不存在近似计算,计算准确度得到很大提升;且相比于其他控保协同方案,该方案在保证距离保护可靠动作的同时也兼顾了故障期间光伏场站对于电网的无功支撑,其低电压穿越能力不仅没有被削弱,反而得到一定的提升。

计及全生命周期成本的公交光伏充电站储能优化配置方法

“双碳”目标下城市公交车全面推进电动化,公交光伏充电站面临并网点负载压力大、运营成本高的问题。提出公交光伏充电站储能优化配置方法。基于大量的调研数据分析公交充电负荷特性,构建公交光伏充电站典型运行场景;综合考虑充电站运营商利益、公共交通通勤需求以及并网点的容量限制,构建计及全生命周期成本的公交光伏充电站电池储能优化配置双层模型。以北京某在营公交充电站为算例,验证了所提配置方法的有效性,量化评估了光伏发电余量上网、公交车充电策略、电网电价及电池购置价格等因素对充电站配置储能运营经济性的影响。

可再生能源配额制下风光储联合参与现货市场的交易决策

可再生能源配额制与现货市场建设的并行推进引起风电发电商、光伏发电商及储能电站(风光储)联合参与现货市场的交易决策发生变化。通过构建双层交易决策模型,对可再生能源配额制下风光储联合参与日前电能量及调频辅助服务市场的交易决策进行求解分析。模型上层以风光储总利润最大化为目标,同时考虑到风光储的内部调控,求解风光储最优交易策略;下层实现日前电能量和调频辅助服务市场的联合出清及绿色证书市场的清算。通过库恩-塔克(Karush-Kuhn-Tucker,KKT)条件、强对偶定理等方法将双层模型转换为混合整数线性规划问题进行求解。最后,通过算例验证了所提模型的有效性。结果表明:所提框架与模型能够优化风光储报量报价决策;可再生能源配额制的引入丰富了风光储的套利手段,风光储内部调控更加活跃;风光渗透率及配额制考核权重的变化对风光储的交易决策有重要影响。

基于时序运行模拟的水火风光储互补系统电源优化配置

系统时序运行模拟是水火风光储互补系统电源规模优化配置的关键环节。对于水火风光储多能互补系统8760逐小时运行模拟,按照小时尺度构建的模型规模很大,直接求解困难。本文提出按时间尺度逐层分解、递进优化的高效求解算法,精确模拟系统全年逐小时调度运行过程。在此基础上,构建双层规划模型对由风电、光伏、水电、火电、抽水蓄能、梯级水电站混合式抽水蓄能和电化学储能等电源组成的并网多能互补系统的电源容量进行优化配置。将模型应用在青海省电网系统中,对风电、光伏、抽水蓄能电站和基于水电站的可逆机组容量进行优化,得到电源最佳配置方案。

新能源大基地风光储容量协调优化配置

大型新能源基地需要协调配置风光火储容量以满足外送要求,其中火电容量及外送通道的容量通常预先确定,从而风电、光伏、储能的容量配置成为影响新能源外送效果的重要因素。为此,针对大型新能源基地,研究了风光储容量优化配置问题,提出了基于新能源外送可靠性的容量配置方法。基于需求侧的负荷曲线,提出了一种聚类方法来优化直流通道的计划传输功率;基于直流计划功率,提出了衡量新能源外送可靠性的送电置信概率指标;基于送电置信概率等约束,构建了风光储容量优化配置的基本规划模型。为了进一步保证在不同的场景下新能源能可靠外送,在基本规划模型的基础上加入场景分布不确定性,提出了风光储容量配置的分布鲁棒规划模型。考虑到分布鲁棒约束包含整数变量,提出了一种迭代算法用于该分布鲁棒规划模型的求解。实际算例验证了所提方法的有效性。

含小水电配电网重要负荷评估及其水光储优化配置方法

为保证含小水电配电网重要负荷的电能质量安全与稳定,发挥水光储系统互补作用,提出一种负荷重要程度评估方法和含小水电配电网重要负荷的水光储优化配置方法。首先,从用户角度出发,基于用电效益指标与用电体验指标2个维度建立负荷重要程度评估体系,采用G1熵权法量化用户节点的重要程度,确定重要负荷节点并将其作为光储接入备选节点,降低光储优化配置求解维度;其次,建立以水光储全寿命周期成本最小、电压偏差平方之和最小为目标的优化配置模型,引入规格化平面约束法求解两目标水光储优化配置问题,得到均匀的Pareto最优解集;然后,计算各解集综合偏移程度函数,得到最优折中解,作为优化配置最佳参考方案;最后,以改进的IEEE 33节点配电网为算例,证明所提的优化配置方法可以改善重要负荷的电压偏差,同时提高投资者的收益。