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。

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.

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.

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。

Optimization and Design of PV-Wind Hybrid System for DC Micro Grid Using NSGA II

The world is heading towards renewable energy, but the two key disputes that stop its well-known adoption are the power production level and the price of the production. Distributed generation (DG), and hybrid systems with battery backup are the solution for uninterrupted power supply. It is obtained using the Multi-Objective Genetic Algorithm (NSGA II). Techno-economic methodology is used in this proposed system for the size optimization. The result is based on the system cost, in order to meet the load requirements. The effect of temporal sampling is optimized using low-rate temporal data. It is compared with hybrid DC microgrid, which has been optimized using high temporal resolution data.

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.

Key technologies and the implementation of wind,PV and storage co-generation monitoring system

The coordinated control of multiple-sources including wind,photovoltaic(PV)and storage brings new challenges to traditional dispatch and control technologies.This paper firstly introduces a framework of wind,PV and storage co-generation monitoring system.Then,key technologies of co-generation monitoring system including day-ahead optimal dispatching,active power coordinated control and reactive power and voltage control are proposed.The framework and the techniques described in this paper have been applied in the National Wind,Photovoltaic,Storage and Transmission Demonstration Project of China,and their validity have been tested and verified.

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.

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.

基于源荷匹配的梯级水风光蓄系统优化运行研究

在“双碳”目标下,我国亟需进行能源结构转型,提高可再生能源在电力系统中的比例。调节性水电站和抽蓄电站具有良好的调蓄能力,可以作为调节电源与风光电源联合运行,从前端减缓风光不稳定出力对电力系统的冲击,促进新能源集中上网消纳。因此,充分利用梯级水电站及抽水蓄能电站的调节性能,制定合理的一体化调度策略,有利于在发电侧实现水风光蓄打捆送出和协同消纳,助力“双碳”目标实现。基于对梯级水风光蓄互补发电系统在短期调度中电网侧负荷需求和梯级水电水资源利用率的考虑,构建以源荷差异最小、梯级水电蓄能增量最大为目标,以常规水电站、风光电站、抽水蓄能电站安全运行条件为约束的短期互补调度模型,并采用粒子群-动态规划内外层嵌套算法对模型进行求解。选取西南某流域常规梯级水电站、抽水蓄能电站及周边风光电站组成的水风光蓄互补发电系统为研究对象进行模拟计算,结果表明:(1)抽水蓄能电站倾向于在梯级电站水头较低时选择泄水发电,而在梯级电站水头较高时选择抽水或维持当前水位不变;(2)所构建模型有效提高了系统总出力曲线与电网负荷曲线的匹配度,实现了梯级水电站之间负荷与水量的合理分配,一定程度上减少了梯级水电站效益损耗,提高了水能利用率,增加了梯级水电蓄能增量,有利于源网协同运行和梯级电站之间的稳定运行。

基于水电储能调节的风光水发电联合优化调度策略

为缓解新能源装机容量扩大引起的弃风弃光现象,在已有梯级水电上下电站之间加入储能泵站,提出风光水储短期优化调度策略。构建以风光水储系统负荷跟踪误差最小、梯级水电站发电量最大和梯级水电站发电耗水量最小的多目标优化调度模型;提出基于季节性自回归移动平均(seasonal auto-regressive lntegrated moving average, SARIMA)模型和Copula函数的风光出力预测模型作为优化调度模型的边界条件,通过SARIMA预测模型将风光出力历史数据分解为季节性分量、趋势分量以及随机噪声余项进行全天96个调度时段风光出力预测,并叠加上基于Copula函数生成风光出力预测误差,然后通过拉丁超立方采样以及K-means聚类进行场景生成和缩减得到5个风光出力场景。选取风光典型日出力数据为例进行算例分析,算例结果表明:所提预测模型较SARIMA模型可以显著提高预测准确度,模型预测风光出力均方根误差从33.34、229.49 MW分别下降至0.697、9.534 MW;所提优化调度策略可以在全年丰、平、枯水期有效减少弃风弃光现象,并可将过剩新能源中的50%转化为上级水库储存水能。

基于虚拟同步机的风-光-储并网系统自适应功频控制策略

风-光-储系统通过虚拟同步发电机(virtual synchronous generator,VSG)并网时,其运行工况变化将引起系统功频波动。针对这一问题,提出一种VSG自适应惯量阻尼功频控制策略。首先,建立VSG的数学模型及功率小信号模型,分析虚拟参数变化对系统稳定性的影响;然后,依据系统受扰时的功角曲线分析惯量阻尼的动态特性,设计了一种分段线性调整函数,并给出参数选取原则;最后,在Matlab/simulink平台中搭建仿真模型验证。结果表明,在工况变化情况下,采用VSG自适应控制的风光储并网系统功频响应得到了改善,相比传统VSG控制具有更好的动态调节性能。

基于变时段设计改进多目标差分进化算法的风/光/火/储日前优化调度

在高比例新能源馈入的新型电力系统中,新能源出力的不确定性导致火电难以满足调度计划的精度需求,风/光/火/储系统的经济调度求解算法面临严峻挑战。为此,提出一种基于变时段设计的多目标差分进化算法。首先按各时段负荷特征构建风/光/火/储系统的变时段日前调度规则。进而以系统运行经济成本与污染排放量为目标,基于多目标差分进化算法求解变时段系统日前调度模型的Pareto解集。最后,用IEEE 39节点系统进行测试。结果表明在风、光、储与火电的约束条件均符合校验的情形下,相较于其他算法,该方法使计算结果更加优化,火电机组出力跟踪调度计划效果显著提高,验证了所提方法的有效性。

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。

计及最小惯量约束的风光火储联合系统优化调度

风、光、储多种新能源并网使系统常常处在低惯量运行场景下,给考虑频率稳定的系统优化调度带来极大挑战。为此提出了一种计及最小惯量约束的多源联合电力系统优化调度模型。首先,综合考虑两项频率指标,计算满足频率指标的系统最小惯量需求,将非线性的频率稳定约束转化为线性的最小惯量约束加入调度模型之中。其次,利用含模糊参数的机会约束表达源荷不确定性对于联合系统的影响,建立模糊参数下的系统优化调度模型。最后,通过IEEE 30节点系统验证了该模型的经济性与安全性。

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。

离网型风光储微电网控制策略研究

为了解决偏远地区电力供应不足的问题,笔者提出一种含风力发电、光伏发电及蓄电池储能的离网型风光储微电网系统。风力发电最大功率点跟踪(maximum power point tracking,MPPT)采用叶尖速比法的控制策略,光伏发电MPPT采用变步长扰动观察法的控制策略,蓄电池储能系统采用基于双闭环控制的充放电控制策略。结合广西地区实际风速及光照强度变化情况,利用MATLAB/Simulink平台对所提出的风光储微电网系统进行了建模及仿真,验证了所提系统的可靠性和控制策略的有效性。

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。