考虑灵活性与经济性的可再生能源电力系统源网联合规划

传统经济性规划方法无法反映电力系统灵活性,难以满足高比例可再生能源电力系统的规划需求,为此,提出一种考虑灵活性与经济性的多目标源网联合规划方法。分析源荷两侧的灵活性需求,并从功率平衡与功率传输两方面实现电源灵活性与电网灵活性的定量评估。在此基础上,综合考虑电源、线路2种灵活性资源,建立兼顾灵活性和经济性的电力系统双层联合规划模型：上层是规划方案的多目标优化决策,实现源网灵活性和经济性的协同优化;下层是多场景运行模拟,对规划方案的灵活性与经济性进行定量评价。IEEE RTS-24节点系统与IEEE 118节点系统的算例结果表明,所提规划方法能够有效响应并平复可再生能源电源与负荷的不确定性功率波动,提高系统的灵活性以及对可再生能源的消纳能力。     

源网荷储多元协同调度体系研究与实践

当前,"碳达峰、碳中和"是我国重要的战略目标,建立以新能源为主体的新型电力系统是实现"双碳"战略的重要手段。为适应新型电力系统的发展需求,提出一种源网荷储多元协同调度体系,通过建立适应电源侧、电网侧、负荷侧各类资源参与的电力市场机制和多类资源协作互动调控平台,有效提升了源网荷储间的协调能力和清洁能源的消纳水平。最后,经山东电网多地市源网荷储协调互动试验及试点应用,验证了所提出多元协同调度体系的有效性。     

考虑系统灵活性约束与需求响应的源网荷协调规划模型

近年来,“弃风”“弃光”问题引起广泛关注,电力系统规划方法亟须做出改进。针对目前电力系统灵活性不能满足新能源消纳需求的情况,在规划模型中设计系统调峰能力约束与调节速率约束。挖掘需求响应对系统的多重影响,并探索将其纳入规划模型中进行统筹考虑。在此基础上,构建源网荷协调规划模型,从系统角度进行电源机组、电网线路与需求侧资源的统筹规划。算例分析验证了所提出模型的有效性。     

基于柔性计算的高比例新能源环境下的电力电量平衡

为解决高比例风光接入给电源规划带来的不确定性问题,提出了一种适用于新能源占比高的能源互联网的电力电量平衡方法。首先将源网荷储用柔性参数的形式描述,并定义了柔性参数的计算法则,在电力电量平衡计算实际场景下用柔性不等式代替了传统的电力电量平衡条件,将不同类型的能源以及电网中源网荷储的不同组成按照其柔性边界进行统一计算。算例验证了基于柔性运算的电力电量平衡方法可应用于系统规划,并且具有良好的经济性、适应性和灵活性。     

考虑源网荷储效益提升的电力现货市场出清优化模型研究

随着我国在“双碳”目标背景下电力现货市场的发展,以风电、光伏等代表的可再生能源将参与到现货市场出清,由于可再生能源的波动性和不确定性,需要通过需求侧响应和储能间的协调,在保证电网调节灵活性的前提下实现市场多主体效益提升,因此开展考虑源网荷储效益提升的电力现货市场出清优化策略研究。考虑参与日前出清阶段各方的效益,将电网不同峰谷差的调节需求纳入到竞价过程中,提出考虑源、网、荷、储收益分配的现货交易体系;为保证系统低碳运行,考虑供能侧的碳排放权交易,建立基于供能侧、储能侧,电网侧、需求侧多方效益协调的电力现货市场出清优化模型,通过算例仿真分析验证所提模型的有效性和优越性。     

基于可靠性均衡优化的含风电电网协调规划

集群开发、远距离外送的规模化风电开发对电力系统规划提出了新的挑战,串序开展电源和电网规划往往将新能源接入的矛盾积压到电网规划阶段,使得电网规划方案难以求解甚至得不到合理方案。为此,从可靠性均衡的角度,提出一种利用虚拟机组进行源网协调规划的方法。该方法针对风电大规模接入后的电网规划,在规划电网的同时对电源规划方案进行反馈及微调,以经济性最优为目标,均衡优化源、网可靠性,确定电源及电网的可靠性优化值,从而得到与电源协调优化的电网规划方案。该方法可以有效减少电网建设投资及电力系统整体投资,并校验电源、电网规划中可靠性均衡的协调性。通过原型系统和测试系统的仿真及分析,验证了所提方法的有效性。     

基于全成本电价的源-网-荷协同规划

提出了基于有效输电成本和全成本电价的源-网-荷协同规划模式、模型与方法。首先,基于结构化有效输电成本辨识方法,确定了输电投资的准许成本回收率。利用全成本电价体现终端负荷对电源及电网资源的利用程度,并通过分布式电源投资规划体现对全成本电价的响应。基于Garver’s 6节点系统的算例分析表明,所提出的基于全成本电价的源-网-荷协同规划模式能够充分体现终端负荷对电源、电网资源的利用程度,在节约自身用电成本的同时提升了电网投资的高效性、有序性、公平性,体现了激励相容的原理,实现了电力资源优化配置的目标。     

面向新型电力系统源网荷储协同的电力平衡方法

在 “双碳目标”的背景下,提出了构建以新能源为主体的新型电力系统.而新能源快速发展和新型用能设 备广泛接入,对传统配电网规划提出了挑战.源网荷储协同的电力平衡是新型电力系统规划的核心,新型平衡资源考虑得越多,电网越经济,但风险也越大,反之亦然,因此需要对平衡进行折中和优化.以负荷预测为基础,综合考虑源网荷储等各方面灵活资源,通过叠加电能替代负荷、常规负荷、新能源出力、用户侧主动削峰填谷、电网侧调峰、 基于激励的需求响应、政府主导有序用电等,得到总负荷曲线、净负荷曲线、自然削峰后曲线、电网侧调峰曲线、平衡曲线与电力需求,创新性地提出了一种面向新型电力系统源网荷储协同的电力平衡方法和流程,助力新型电力系统 建设.     

考虑源-网-荷不确定性的增量配电网规划研究综述

随着电力体制改革的全面深化,具有清洁性、智能性与竞争性的增量配电网应运而生。增量配电网不仅结构灵活,同时鼓励多种具有间歇性的分布式电源与新型负荷接入配电网侧。传统配电网的规划技术已难以适应源-网-荷均存在不确定性的增量配电网。基于以上现状,在考虑源-网-荷不确定性的前提下对增量配电网规划研究进行综述。分别从增量配电网中新型源-网-荷发展现状,适用于增量配电网规划阶段的不确定性分析方法和常见的规划研究方法等三个方面进行归纳分析。最后给出了考虑源-网-荷不确定性的增量配电网规划总结与未来展望。     

考虑风电消纳的综合能源系统“源-网-荷-储”协同优化运行

针对因传统的热电联产(Combined Heat and Power, CHP)"以热定电"运行方式导致的弃风问题,提出一种考虑风电消纳和运行经济效益的综合能源系统"源-网-荷-储"协同优化运行方法。在源侧通过热泵和储能设备解耦CHP"以热定电"运行约束,在网侧构建了稳态电-热潮流,在负荷侧考虑了综合需求响应,提升系统的风电消纳空间。系统以建设运行总成本最小为目标,考虑了能量平衡、稳态电-热潮流和CHP出力等约束条件,构建了考虑风电消纳的综合能源系统"源-网-荷-储"优化运行模型。最后,通过风机的33节点电网和8节点热网构成的综合能源系统验证所提方法的正确性和有效性。多场景仿真结果表明,该方法可有效提升风电消纳空间和系统经济效益。     

发电扩容与输电扩容的协调优化模型

以电厂和电网分离为主要特征的电力市场化改革给电力扩容规划带来了巨大的冲击。如何协调好发电与输电的扩容直接关系到电力系统的稳定运行和健康发展。通过分析市场化改革后电力扩容规划存在的主要问题,构筑了发电扩容与输电扩容的协调优化模型。该模型中提出了利用协调因子的思想来解决电力扩容的规划风险和保障竞争性电力市场的电价机制。协调因子计及了缺电成本和输电利用成本,这不仅能充分反映电力扩容的规划风险,而且能使双方共同承担其风险,从而促进两者扩容的协调。文章为厂网协调发展探索了新的途径。     

Impact of load management and joint ownership of generation of two interconnected systems utilizing joint cumulants and the bivariate Gram-Charlier expansion

As oil and gas prices continue to increase, many electric utilities are turning to load management as a means of reducing their capital and operating costs. Different load management approaches are considered, and their effect on the global production costs of two interconnected systems is studied. A probabilistic technique for the calculation of production cost of two interconnected systems with joint ownership of generation is developed. A comparative study on production cost is made with and without a jointly owned generating unit. The method is based on the notion of statistical cumulants and the application of the bivariate Gram-Charlier expansion. Joint cumulants are used to represent the joint probability density function of the two systems' loads, and also to represent the probability density function of the outage of the jointly owned generating unit. Demand correlation is considered.     

Modelling the partial planned outages in production costing simulation

Thus paper presents two ways of modelling such scheduled maintenance whose length is less than that of the simulation period (called partial planned or scheduled outages in the paper). The present author suggests using modified forced outage rate instead of derated capacity in this case. The effect of the different representations is shown on a very simple numerical example by comparing the loss-of-load probability, the energy not served and the expected energy generations of the units. The paper concludes that the modification of the forced outage parameter of units is more appropriate than derating the capacity.     

面向高比例可再生能源的输电网规划方法研究进展与展望

为应对高比例可再生能源接入带来的消纳问题,提出了以多场景技术、鲁棒优化技术和协同规划技术为核心的输电网规划理论,涵盖不同适用条件或需求场景下的4种不同规划方法,即基于多场景的输电网随机规划方法、基于概率驱动的输电网鲁棒规划方法、考虑多源互补的网-源协同规划方法以及与配电网相协同的输电网规划方法,能够从输电网规划的角度在安全稳定前提下提高可再生能源消纳能力.在此基础上,对未来输电网规划方法进行了展望,提出了满足更高安全稳定需求、协同更广泛的源-网-荷-储柔性互动、推动大数据应用和挖掘电力市场机制激励空间的可能研究方向,并探讨了研究难点和解决方式.     

A relation-checking algorithm for maintenance of rule-based systems

A representation for a complex knowledge base is proposed. This representation is used to define the relations that may exist between a pair of rules. The relations defined are cause-effect, mutual exclusion, redundancy, conflict, subsumption, implication and unnecessary condition. An algorithm to detect these relations is presented. An example of the application of this algorithm to a power system problem is given.     

Electrical safety in hazardous environments

The paper gives an overview of the requirements for electrical equipment in potentially explosive atmospheres. Flameproof, intrinsic safety, increased safety, non-sparking, pressurization, purging, special protection and flame arrestor methods of protection are all described. The method by which equipment can be shown to be safe in a whole range of gases, by testing in a single test gas, is described. It is shown how the more recently introduced methods of protection, increased safety and non-sparking can be applied to almost any electrical equipment which does not produce an arc or a spark in normal use. Direct and indirect methods of overload protection for increased-safety motors are compared and it is shown that valuable production time can be unnecessarily lost when overcurrent protection is used.     

Incorporating explicit loss-of-load probability constraints in mathematical programming models for power system capacity planning

Current methodologies for incorporating reliability constraints in optimization models for capacity expansion planning are reviewed. In addition, a chance reliability constraint that can be incorporated into a mathematical programming model as a linear constraint is developed. Reliability is measured by loss-of-load probability. The constraint is based on a first-order approximation to the Gram-Charlier series representing the density function of available capacity minus load. Numerical results showing good agreement between the linear approximation and actual loss-of-load probability are presented.     

Electric Power and Heat Generation Expansion Planning

Abstract

A short-term electric power and heat generation augmentation planning (EPHGAP) is portrayed and evaluated here. The objective of EPHGAP is to find out the most cost-effective and dependable expansion plan for meeting the forecasted electrical power demand and heat demand over a long-range horizon while fulfilling a large number of technical, cost-effective, reliability, and social constraints. The EPHGAP problem is a big-dimensional highly constrained mixed integer nonlinear programing (MINLP) problem. The general algebraic modeling system (GAMS) environment has been used to implement the proposed formulation, and the EPHGAP problem is solved by using Basic Open-source Nonlinear Mixed Integer (BONMIN) solver. An archetypal test system with existing thermal power plants, cascaded hydropower plants, cogeneration units, heat-only units and candidate cogeneration units, and cascaded hydro plants is considered to evaluate the proposed methodology. Simulation outcomes of the test system have been matched up to those acquired by differential evolution and particle swarm optimization. It has been observed from the comparison that the recommended BONMIN solver has the capability to bestow with superior quality solution.     

含分布式电源的配电系统规划

随着分布式发电(DG)在电力系统中所占比重越来越大,对传统的电力系统规划提出了新的挑战和要求.重点讨论了包含DG的配电网规划的两个方面,即DG的布点规划和配电网扩展规划问题,并为解决含DG的配网规划问题提供了一种思路.     

Considering risk of cascading line outages in transmission expansion planning by benefit/cost analysis

It has been shown that large blackouts happen more likely than may be expected. Recent investigations revealed that cascading outages are the major cause of power system blackouts. Therefore, risk of cascading outages must be considered in the planning and operating procedures. In this paper a novel procedure is proposed for transmission expansion planning (TEP) by using the ORNL–Pserc–Alaska (OPA) model. Some improvements are introduced to this model for choosing more effective candidate transmission lines to be used in TEP regarding risk of cascading outages. A nonlinear estimation is used to assess the consequences of blackouts after cascading transmission line outages. The power law as a fingerprint of self-organized criticality in power systems is used to calculate the likelihood of blackouts. The benefit of each policy to expand the transmission system is derived from risk assessment and the best one is picked out using benefit/cost analysis. The simplicity of the proposed method makes it appropriate in real life. The proposed method is applied to test systems to investigate its applicability. The results provide motivation for considering the risk of cascading line outages in TEP that afford substantial saving to society.