考虑多能源协同的可再生能源电网快速解列电压优化控制策略北大核心CSCD

针对含可再生能源接入的电力系统在发生故障后,使得电网中部分机组运行解列,其对电网电压造成影响的问题,提出了一种考虑多能源协同的可再生能源电网快速解列电压优化控制策略。首先,分析电/气/热等多种能源间的转换特性和可调节特性,并分析含电/气/热等多种能源转换系统接入可再生能源电网后系统的运行特性,建立含多能源转换系统的可再生能源电网稳态模型;然后,考虑可再生能源电网解列时系统中重要负荷电能恢复量、系统电压波动量两个优化目标,建立可再生能源电网快速解列电压优化控制模型,并对控制模型进行求解;最后,以西北某地区电网运行数据为基础,搭建含多能源转换系统的可再生能源电网等值模型,分析并验证文章提出的电网快速解列电压优化控制模型的可行性和有效性。     

可再生能源电厂并网对地区电网的影响

生物质能发电、风电、水电等可再生能源机组的并网将改变地区原有的电力系统的特性.文章从地区电网的动态稳定性、供电可靠性、调度运行、网供负荷预测、电能质量等方面就可再生能源电厂并网对地区电网的影响进行了分析,对如何消除不利影响,实现电网安全、稳定、经济地运行,提出了一些对策.     

一种可再生能源并网的最大容量边界计算方法

可再生能源大规模接入电网是一种解决当前世界面临的能源和环境问题的有效方法,但是也给电网的安全运行带来了新的问题。该文首先通过引入支路电流作为电力网络方程的状态变量,进而建立了可再生能源接入电网的最大容量边界条件方程,组成了用于计算可再生能源接入最大边界容量的方程组;然后求解该方程组得到在给定负荷情况下可接入的可再生能源最大容量,并通过容量裕度指标评估电网运行的安全性;最后通过多节点可再生能源并网仿真计算结果表明该模型是有效的,能够为电力部门安排可再生能源的运行方式提供辅助决策。     

风、光高渗透率电网中考虑频率稳定的可再生能源承载力研究

风电、光伏系统的弱惯量、无惯量特性以及在最大功率跟踪运行的特点影响电网频率的稳定。文章建立了包含常规发电机组和可再生能源发电机组的电网频率响应综合模型;提出了一种考虑频率稳定约束的可再生能源承载力评估方法;在Matlab/Simulink中对所建模型进行仿真,得出电网在不同可再生能源渗透率下的频率响应指标。算例分析表明,文章提出的方法能够快速准确地获得电网可再生能源承载力。     

分布式供能系统发电机组接入上海电网的思考

在介绍分散发电的定义及其在上海电网内发展和应用的基础上，分析了分散发电机组接入电网的有利和不利因素。分散发电机组一般容量较小，投资的经济性和设备、电网的安全可靠性之间的矛盾，在分散发电并网运行中比较突出；机组容量、电压等级、电能质量等是分散发电的接入系统的关键，通过技术手段的可以处理解决这一矛盾。     

燃煤机组最小边界出力稳定性评价方法分析

为进一步提升电网对可再生能源发电量的消纳水平,提高电网低谷运行的可靠性,开展了燃煤机组最小出力运行方式的核定研究.基于电站锅炉切圆燃烧机理与运行调整技术,并兼顾安全、稳定、环保、节能等指标,进行了最小出力稳定性评价方法探讨,并在示范机组完成了25％ 额定负荷的稳燃能力评价,以供同类进行借鉴.     

计及不确定性的多类型发电机组联合调度优化模型

为了促进可再生能源并网,解决可再生能源机组在内的多类型发电机组联合优化调度问题,引入全额收购可再生能源发电,由火电机组提供备用、允许适度弃风,由火电机组提供备用以及水火机组联合提供备用的可再生能源发电三种不同方案。首先构建了涵盖风、光伏、水力机组的可再生能源机组发电处理模型;再结合设定的三种方案组建了多类型发电机组节能调度优化模型;最后,基于基础数据,得出该节能调度优化模型的发电系统总煤耗、备用煤耗、系统发电成本、启停成本、弃风量及弃水量等关键指标的优化效果,对多类型发电机组联合调度优化具有一定的指导意义。     

储能电站接入配电网的可靠性评估

大量分布式电源的接入,有利于清洁能源的合理利用,但是其间歇性和波动性给电网造成的功率冲击严重威胁电网的安全稳定运行。为了平衡风电光伏等分布式电源对电网的冲击,在配电网接入储能装置是一种十分有效的措施。通过可靠性分析的方法,分别计算接入点不同和接入容量不同的储能电站对配电网供电可靠性指标的影响。并以某地区的实例来评估储能电站接入对配电网可靠性的影响     

分布式电源电动汽车充电站储能系统电价分析

含分布式电源的电动汽车充电站的可再生能源供给常常小于电动汽车充电负荷,须要配电网辅助补充部分电能,不利于配电网的稳定运行。文章提出基于微电网内不平衡率的充电站储能系统的电能与电网电能联动策略。考虑配电网有峰、谷、平3种电价,故将充电站储能系统SOC分成3部分与之相对应,根据微网内可再生能源实时出力与负荷求出不平衡率U_R。当充电出现缺额时,由充电站储能系统和电网以不平衡率为比例协同补充充电缺额,实现了微电网内的能源协调控制。文章采用蒙特卡洛方法模拟电动汽车负荷,通过对比不同用户响应度的配电网等效负荷和充电站储能系统SOC,验证了该策略在微电网运行优化的有效性。该策略充分发挥了充电站储能系统和电网的联合运行优势,减小了电网负荷峰谷差,优化了电网负荷曲线。     

含高渗透率可再生能源的配电网可靠性分析

以高渗透率可再生能源接入配电网为背景,分析分布式电源的渗透率对所接入系统的供电模式以及可靠性分析的影响。在建立光伏、风电、储能以及含有家用电动汽车充电桩的负荷模型的基础上,提出以分布式电源为中心的区域供电模式、故障影响分析和功率匹配策略;并基于序贯蒙特卡洛随机模拟方法,设计配电网可靠性评估算法;最后采用所提出的算法对改进后的IEEE RBTS Bus2进行可靠性评估,通过算例分析给出区域供电模式下的可靠性指标,并对比不同可再生能源对可靠性指标的影响,为含高渗透率可再生能源的配电网的可靠性分析以及电源规划提供参考。     

Influence of photovoltaic generation model and time resolution on the reliability evaluation of distribution systems

This paper aims to investigate the influence of photovoltaic (PV) generation on reliability evaluation of distribution systems. Two PV generation models are used to predict the output power injected into the grid, taking into account the main relevant environmental variables, the irradiance and ambient temperature. Issues that directly affect the output power, such as the spatial smoothing effect due to the plant size and the influence of the irradiance and temperature measurement interval are taken into consideration. Using measurement time series of irradiance and local temperature, the models are used to generate power series in 4‐minute and hourly resolutions. The generated power series are used in a reliability assessment model, with the objective of evaluating the impact of solar resource variability on the reliability indices of the system. Case studies on the IEEE RBTS‐Bus 2 and on the real distribution system of Fernando de Noronha in Brazil are presented and discussed, for power plants of different capacities, considering the effect of the PV generation models, the temporal resolution of the time series and the spatial smoothing of the power output fluctuations. The results show that the power time series in hourly resolution significantly underestimates the frequency of interruptions. For the real system, this index is underestimated at the system level (up to 43%) and at the load points (up to 72%). On the other hand, for the interruption duration index, the temporal aggregation results in a small underestimation (just 4%). The results also indicates that the smoothing effect is irrelevant for typical PV system sizes of distribution systems with discretization equal to or above 4 minutes.     

A review on reliability assessment for wind power

The application of wind energy in electric power systems is growing rapidly due to enhanced public concerns to adverse environmental impacts and escalation in energy costs associated with the use of conventional energy sources. Electric power from wind energy is quite different from that of conventional resources. The fundamental difference is that the wind power is intermittent and uncertain. Therefore, it affects the reliability of power system in a different manner from that of the conventional generators. This paper, from available literatures, presents the model of wind farms and the methods of wind speed parameters assessment. Two main categories of methods for evaluating the wind power reliability contribution, i.e., the analytical method and the Monte Carlo simulation method have been reviewed. This paper also summarizes factors affecting the reliability of wind power system, such as wake effect, correlation of output power for different windturbines, effect of windturbine parameters, penetration and environment. An example has been used to illustrate how these factors affect the reliability of wind power system. Finally, mainstream reliability indices for evaluating reliability are introduced. Among these reliability indices, some are recently developed, such as wind generation interrupted energy benefit (WGIEB), wind generation interruption cost benefit (WGICB), Equivalent Capacity Rate (ECR), load carrying capacity benefit ratio (LCCBR).     

Reliability and economic evaluation of small autonomous power systems containing only renewable energy sources

Evaluation of reliability performance in every power system has to be done within a cost–benefit framework. This approach, however, is a very time consuming task, especially for systems that contain a large number of possible configurations, so simpler techniques referred to the calculation of reliability indices are used. In small autonomous power systems (SAPSs), such an evaluation uses mainly deterministic criteria. This approach, however, cannot be applied in SAPS that contain only renewable energy sources, due to the intermittent nature of the provided energy. In this paper, a complete reliability cost and worth analysis is implemented for these systems, combined with the calculation of some basic probabilistic indices, in order to discover their performance and propose the appropriate of them as a criterion of optimal system configuration. This paper proposes that normalized energy reliability indices as system minutes and energy index of unavailability can be used as adequate criteria of system's optimal performance. This conclusion is validated through a large number of sensitivity analysis studies that are based on different maximum annual loads and different mix of load types.     

自启动燃料电池发电系统

针对全社会对绿色动力的需求,提出一种适用于作为备用电源、游览车和微型轿车动力电源的质子交换膜燃料电池发电系统,系统具备自启动、燃料利用率高、可靠性高、结构简单等特点,文中介绍该燃电池发电系统的特点和工艺流程。     

Reliability analysis of solar photovoltaic system using hourly mean solar radiation data

This paper presents the hourly mean solar radiation and standard deviation as inputs to simulate the solar radiation over a year. Monte Carlo simulation (MCS) technique is applied and MATLAB program is developed for reliability analysis of small isolated power system using solar photovoltaic (SPV). This paper is distributed in two parts. Firstly various solar radiation prediction methods along with hourly mean solar radiation (HMSR) method are compared. The comparison is carried on the basis of predicted electrical power generation with actual power generated by SPV system. Estimation of solar photovoltaic power using HMSR method is close to the actual power generated by SPV system. The deviation in monsoon months is due to the cloud cover. In later part of the paper various reliability indices are obtained by HMSR method using MCS technique. Load model used is IEEE-RTS. Reliability indices, additional load hours (ALH) and additional power (AP) reduces exponentially with increase in load indicates that a SPV source will offset maximum fuel when all of its generated energy is utilized. Fuel saving calculation is also investigated. Case studies are presented for Sagardeep Island in West Bengal state of India.     

Reliability evaluation of power system incorporating wind farm for generation expansion planning based on ANLSA approach

Reliability evaluation of power‐generating systems gives a mechanism to guarantee proper system operations in the face of different uncertainties including equipment failures. It is regularly not attainable to identify all possible failure states to figure the reliability indices because of the large number of system states engaged with system operations. Therefore, a hybrid optimization technique is required to analyse the reliability of the power system. This paper proposes a hybrid optimization technique to evaluate the reliability of a power system for the generation expansion planning incorporating wind energy source. The proposed hybrid methodology is the joined execution of both ant lion optimization algorithm (ALO) and lightning search algorithm (LSA), and it is named as ANLSA. ALO searching behavior is enhanced by LSA. Through the inherent convergence mechanisms, ANLSA search the meaningful system states. The most probable failure states contribute reliability indices of power generating system including mean down time (MDT), loss of load probability (LOLP), loss of load expectation (LOLE), loss of load frequency (LOLF), and expected demand not supplied (EDNS). Furthermore, ANLSA is utilized to assess the reliability of system under normal condition, integration of wind farm with capacity of 150 MW, and considering spinning reserve requirement (SRR). By then, the proposed work is actualized in MATLAB/Simulink platform and it is demonstrated on IEEE reliability test system (IEEE RTS‐79). Furthermore, the statistical analysis of proposed and existing techniques such as Monte Carlo simulation (MCS) and discrete convolution (DC) is considered. The comparison results demonstrate that proposed approach confirms its ability for evaluating the power system reliability.     

计及无功电源故障的含风电场发电系统可靠性评估

针对现阶段含风电发电系统可靠性评估中尚未考虑无功功率影响的缺陷,在风电场常规可靠性评估模型的基础上,考虑了无功电源故障的影响,建立了风电场综合可靠性评估模型,定义了表征系统局部无功不足的可靠性指标。采用三级切负荷策略对计及有功功率短缺、无功功率短缺、电压越限的含风电场发电系统进行了可靠性评估。根据第三级切负荷策略确定了最佳无功补偿位置,应用就地无功补偿代替负荷切除,有效解决了电压越限问题。并以太原220kV系统为例,验证了该方法的有效性,为确定最佳无功补偿位置提供了依据。     

风功率不确定性对电网的影响及其应对措施

讨论了适应不同研究需要的风功率概率模型、时间序列模型及预测误差模型。在现有研究工作的基础上讨论了风功率的不确定性对发电系统可靠性、电力系统规划及系统短期调度的影响。研究表明,风功率不确定性对电力系统的影响大多是负面的。还简要分析了利用储能系统改善风功率不确定性的可能性。     

风能与水能互补发电系统的研究

论述了水能与风能两种自然资源特性及互补的必要性和经济性,在此基础上提出风能与水能互补发电系统,构建了风能与水能互补发电系统的结构图、探讨了互补发电系统的运行策略及仿真运行与设计。风能与水能的互补开发、综合利用可提高发电系统的可靠性与稳定性,是一种行之有效可再生能源的利用方式。     

光伏发电系统在轨道交通中的应用研究

轨道交通是目前重要的交通方式,为了保证轨道交通运行的可靠性,分析光伏发电系统在轨道交通中的应用,通过建立光伏系统数学模型,阐述最大功率点算法,并使用PSCAD/EMTDC仿真软件建模,重点分析了光伏发电系统的输出与光照强度和电池温度之间的关系。