Probabilistic production costing: An investigation of alternative algorithms

New production cost algorithms are compared with representative algorithms used by the electric utility industry. Accuracy and efficiency of new and conventional algorithms are assessed using the framework of probabilistic production costing. Their usefulness in the context of long-term capacity expansion models is evaluated. Accuracy is considered in two contexts: first, in fitting original customer demand; and second, in approximating generator forced outages. Comparisons of algorithm efficiency are based on an EPRI synthetic system with dispatch of 174 units. Conventional algorithms are drawn from models in use by TVA, Southern Company and MIT. The new algorithms are based upon continuous functions for fitting the equivalent load curve.     

含风电场电力系统的Cornish-Fisher级数概率潮流计算

利用基于Cornish-Fisher级数展开的方法研究了含风电场电力系统的概率潮流分布问题.该方法以半不变量为纽带,构建了待求变量和已知变量之间的直接耦合关系;以确定性的潮流计算为出发点,得到了具有较高精度的概率潮流分布结果.仿真计算表明:与基于蒙特卡洛仿真抽样法的概率潮流计算方法相比,在保证计算结果精度的前提下,该方...     

Probabilistic cost prediction for submarine power cable projects

It is estimated that Europe alone will need to add over 250,000 km of transmission capacity by 2050, if it is to meet renewable energy production goals while maintaining security of supply. Estimating the cost of new transmission infrastructure is difficult, but it is crucial to predict these costs as accurately as possible, given their importance to the energy transition. Transmission capacity expansion plans are often founded on optimistic projections of expansion costs. We present probabilistic predictive models of the cost of submarine power cables, which can be used by policymakers, industry, and academia to better approximate the true cost of transmission expansion plans. The models are both generalizable and well-specified for a variety of submarine applications, across a variety of regions. The best performing statistical learning model has slightly more predictive power than a simpler, linear econometric model. The specific decision context will determine whether the extra data gathering effort for the statistical learning model is worth the additional precision. A case study illustrates that incorporating the uncertainty associated with the cost prediction to calculate risk metrics - value-at-risk and conditional-value-at-risk - provides useful information to the decision-maker about cost variability and extremes.     

Probabilitic flows for reliability evaluation of multiarea power system interconnections

The development of a solution method and computer program for the evaluation of multiarea reliability is reported. An interconnected power system is modelled as a capacitated network with probabilistic arc capacities. The proposed solution method consists of an analytic state space decomposition phase and a Monte-Carlo simulation phase. An optimization problem is solved to minimize the total computational time for the two phases. The solution of the optimal mix problem determines the termination of the decomposition phase and the size of sample for the Monte-Carlo phase. A new reliability index, the inadequate transfer capability, is introduced. This measure indicates the relative effectiveness of either increasing existing capacities or opening new interconnections between two areas. The proposed method has been incorporated into a computationally efficient production grade software package, called Remain (Reliability Evaluation of Multiarea Interconnections). The application of Remain to a seven-area example for planning-system enhancement is given. Computational-times data is also presented.     

Computerized interactive model approach to electrical distribution system planning

The results are described of a research effort to apply the latest technology to the problem of energy distribution-system planning. The interactive computerized model used promises to be a valuable means of analysing and planning for future distribution systems.     

含风电场的电力系统动态优化潮流

为了体现风电的环境价值,建立电力市场环境下大规模异步风电并网电力系统动态最优潮流模型。首先计算风电场功率输出期望值,在此基础上,引入基于风电场极限穿透功率的风电弃风运行惩罚成本(WAOPC)以处理弃风行为;然后考虑火电机组的排污特性,并用名义环境补偿成本(NECC)来量化火电环境成本;最后引入风电备用成本(RCCC)来处理随着系统风电穿透水平增加而引起的系统二次备用上升。仿真表明,所建立的模型既考虑了电能生产所产生的环境污染和资源消耗等外部成本,同时也计及了因弃风行为造成的风电损失,合理地反映了以风电能源形式的电能价值。     

发电企业作业成本通用模型研究

以火力发电企业为例,围绕发电企业作业成本通用模型研究的主要环节,即资源库模型的建立、作业库模型设计、成本对象模型设计、成本动因模型设计等,分析发电企业自身特点对通用作业成本模型设计产生的影响,总结和归纳每一个环节的基本设计原则,并进一步提出了该环节具体的模型设计结构。考虑系统性和通用性原则,提出以企业资源规划(ERP)科目表为设计蓝本建立资源库;参考EUCG国际标准,以建立层次清晰的通用电力作业库;确定以发电设备系统及机组为核心的2层成本计算对象,用以归集设备和机组的相关成本。发电企业通过对作业成本法的合理运用,可以重点加强设备维修、维护的管理水平和成本核算的广度及深度。     

Direct method for evaluation of bulk power system reliability Part 2: Solution algorithm

A new approach to the problem of evaluation of bulk power system reliability has been proposed in Part 1 which also includes a theoretical foundation of the approach. A solution algorithm for the same approach is presented. The algorithm is divided into five major steps. The details of each step are described and an illustrative example is given.     

Direct method for evaluation of bulk power system reliability Part 1: Theoretical foundation

The reliability of a bulk power system is defined as the probability of the set of states for which the DC load flow is satisfied with a particular demand and there is no line overload. A direct method to find such a set of working states, which does not require the solution of a load flow, is proposed. The method involves (i) replacing two sets, one defined by the constraints on line flows and the other by the constraints on phase angles, by two families of hyperboxes; and (ii) identifying the states for which there occur points in a pair of hyperboxes, one from each family, that satisfy the flow-angle relations. The theoretical foundation of the method is presented.     

基于可信性理论的含风电电力系统电压稳定概率评估

由于风速变化对大规模风电并网后的电力系统电压稳定造成影响,提出了对风速进行模糊模拟的可信性静态电压稳定分析方法。该方法不仅能够计算出含有不确定因素时系统降阶雅可比矩阵对角元素的期望值和均方差,而且建立了基于可信性意义下的静态电压稳定指标。该方法避免了不确定参数分布函数类型的假设和参数统计对分析结果的影响,仅需根据不确定参数的实际变化范围和描述不确定参数的隶属度函数类型确定计算结果。最后,与采用两点估计法和蒙特卡洛仿真法后的计算结果进行对比,证明了所提方法在计算精度和计算量方面的优越性。     

基于MATLAB-PSASP的光伏并网暂态稳定计算模型

在MATLAB/Simulink环境中搭建了光伏发电系统模型,其采用最大功率点跟踪(MPPT)控制算法,并加入继电保护逻辑控制模块。通过PSASP的用户程序接口,可将该模型以电流源的形式接入电网模型进行暂态稳定计算。同时提出在电流源并网模式下并网光伏发电系统控制其与电网的无功功率交换为0,因此在潮流计算中可将光伏电站设为PQ节点,并设无功功率为0。CEPRI 36节点系统的仿真结果验证了该模型的正确性,并表明所提模型比常规同步电机二阶经典模型对电网故障的反应更为灵敏,但其对于改善全系统的暂态稳定性作用不大。     

含不确定性电源的电力系统柔性生产模拟

大规模不确定性电源接入电网给电力系统带来了随机性、波动性和间歇性等不确定性因素,现有的随机生产模拟理论不能很好地解决上述形势下的电源规划和评估。鉴于此,提出了“电力系统柔性生产模拟”的概念并研究了其一般方法和流程。该方法不仅能得到传统随机生产模拟的可靠性和经济性指标,还给出了考虑不确定性电源和储能接入下的不确定性电源发电的容量可信度以及可避免费用等。所提方法还从电网调峰和调频两个层面和时间尺度评估了系统的弃能电量。在调峰层面,基于电网调峰需求和调峰能力加以分析给出了该层面的弃能电量;在调频层面,采用多场景分析理论给出了调频层面弃能电量的评估方法。电力系统柔性生产模拟能为含不确定性电源的电源规划及评估提供理论依据,并能全面评估不确定性电源的接入对电网造成的影响。对2020年西北规划电网的仿真计算验证了所提方法的正确性和有效性。     

Electromechanical distance measure for decomposition of power systems

A concept of electromechanical distance measure which reflects the interaction among the machines during a transient is presented. This measure is then used as a criterion for decomposing the power system into regions, each requiring different levels of model complexity. The complexity of models for regions decreases progressively away from the point of fault. Grouping of coherent generators within each region can also be done using the results of this analysis. The analysis takes into account the fault location, magnitude of disturbance, and changes in boundary between the study area and the external system.     

电力工程造价管理探讨

通过对预、结算进行全面、系统的检查和复核,及时纠正所存在的错误和问题,使之更加合理地确定工程造价,达到有效地控制电力工程造价的目的。     

Databases for power system calculation

Large database management systems have been developed for commercial applications. Since the volume of data to be processed in technical power system calculations also increases continuously, there is rising interest in using database systems for power systems calculations also. A detailed requirement analysis based on a proposed classification of database approaches is combined with a survey of the state of the art and indications of further development needs.     

考虑成本系数变动情形下的发电商报价策略研究

研究了在现货市场和合同市场两种情况中,当发电商报价函数的成本系数服从一定分布时的发电商报价策略,得出了其最优产量解,并进行了算例计算。发现不论发电商成本函数中的成本系数服从哪种分布,发电商总可以通过在合同市场和期货市场两个市场套利来规避风险。     

Probabilistic simulation incorporating single and multiple hydroelectric units with stochastic energy availabilities

Several extensions are devised to incorporate single and multiple energy-limited hydroelectric units with stochastically-known energy availabilities into probabilistic simulation models of hydrothermal power systems. The methods devised do not present any particular methodological difficulties, other than the need for skillful and careful programming.     

全寿命周期成本理论在电网规划中的应用分析

在简要介绍电网全寿命周期成本理论的基础上,对其在电网规划中的应用原理及国内主要应用情况进行了阐述。通过在配网规划中的应用实例说明电网规划中引入全寿命周期管理的必要性和广阔前景,建议规划工作者大胆尝试将全寿命周期理念引入规划,以促进电网企业管理水平和经济效益的提升。     

基于成本最优的含储热光热电站与火电机组联合出力日前调度

含储热光热发电的优势体现为良好的出力可控性和可调度性,合理调度光热发电能够有效降低系统运行成本。以成本最优为目标,从光热电站的光电转换特性分析角度出发,在计及各项运行约束的基础上,提出含储热光热电站与火电机组联合出力调度策略。该策略综合考虑火电机组发电成本、光热发电并网消纳的环境效益和运行维护成本、系统旋转备用成本以及电网安全运行约束等因素,从而确定光热电站在既定储热容量下的最优出力调度策略。基于遗传算法,通过IEEE 30节点算例验证了所提方法的可行性与有效性。     

基于精益生产理念的电力企业生产计划研究

提出了上海电力运用精益生产理念,在公司"一横三纵"层面,即在市调与3家地调管辖范围内实施综合生产计划项目,第一次将生产计划与调度计划有机结合,通过打破各部门之间的信息壁垒,加强综合生产计划编制的规范性,并将公司业务中与综合生产计划相关的各环节纳入其目标管理,建立统一的综合生产计划系统平台,提高计划安排的合理性和集成性,降低计划变更率和设备重复停役率.