线路传输容量约束对电力市场均衡的影响

电力市场中最优竞标可描述成一个两层优化问题,其中在下层优化中ISO通过求解最优潮流(OPF)问题来最大化社会效益,而在上层优化中,电力供应商(发电商)通过线性供应函数竞标来最大化各自利润。线路传输容量约束将导致电力供应商决策空间分成不同区域,在任一决策区域内约束状态严格不变(或为严格等式,或为严格不等式)。而不同决策区域内约束状态不同又导致电力供应商在不同区域内有相应不同的最优策略。从市场均衡定义出发,通过在不同决策区域中搜索发电供应商最优响应曲线的交点来定位市场均衡点。文中首先研究一个简单的3节点系统,发现线路传输容量约束的引入导致市场可能有一段连续的均衡点,或是不存在均衡点;且如果均衡点存在,那么只能在约束边界式上发现,即不存在节点电价差或不存在网络拥塞费用。通过分析上述结论的内在因素,将其推广到复杂系统中。算例检验表明了文中分析的正确性。     

Impacts of Network Constraints on Electricity Market Equilibrium

Nash equilibrium is usually used as the solution of generator's strategic bidding in electricity markets. The available literature has shown by simulation that multiple market equilibria or no pure equilibrium may be induced after the inclusion of network constraints (transmission constraints). This paper presents a systematical analysis for the impacts of network constraints on the market equilibrium in oligopolistic electricity markets. In our modeling, the independent system operator (ISO) dispatches generation and determines nodal prices via solving an optimal power flow (OPF); and the individual generator optimizes its submitted supply function with Nash-supply function equilibrium (SFE) strategy, after taking into account ISO's decision-making process on dispatched generations and nodal prices. The conditions for the existence of equilibrium are given, and it is shown that there may be multiple equilibria or no pure Nash equilibrium. The equilibrium, if it exists, will be at a point where generators pay no congestion charge     

Supply function equilibrium bidding strategies with fixed forward contracts

During the last 15 years, the regulatory framework for the wholesale sector of the electricity industry has been replaced in many countries by market competition. In such an environment, electric firms compete through both spot market bidding and bilateral contract trading. Firms have to consider their forward contract positions when they make spot market decisions. In this paper, we propose a linear asymmetric supply function equilibrium (SFE) model with transmission constraints to develop firms' optimal bidding strategies considering forward contracts. The characteristics of firms' behaviors are analyzed under the induced equilibrium conditions. The model is applied to the real-time energy market of the Electric Reliability Council of Texas (ERCOT). The effects of forward contracts on the ERCOT market are evaluated. It is shown that the model is able to capture features of bidding behaviors in the ERCOT market.     

计及输电约束和需求方投标的线性供应函数均衡点的求解算法

在具有需求方投标的电力市场中，需求方通过策略性投标以获取最大利润，从而影响了市场的均衡结果。该文对线性供应函数均衡的应用加以推广，将需求方投标纳入线性供应函数均衡中，基于最优潮流灵敏度，在时市场中考虑需求波动的情况下，推导出了整个市场均衡点的迭代求解算法。算例表明，无论输电约束存在与否，需求方投标均可显著降低发电商行使市场力的能力；在没有输电约束的情况下，纯策略的线性供应函数均衡是存在的；在输电约束起作用的情况下，随着需求的升高，会达到阻塞状态的纯策略的线性供应函数均衡。     

Market Incentive Index for Studying Equilibrium Between Vertically Linked Oligopolistic Electricity and Fuel Markets

A new index,called the market incentive index is proposed for studying the equilibrium between fuel and electricity markets.Firstly,a game theoretic model with a monopolistic upstream fuel market and a...     

考虑输电网约束的电力市场有限理性古诺博弈的动态演化研究

为了模拟电力市场中发电商的有限理性博弈行为,该文提出了考虑输电网约束的有限理性Cournot动态博弈模型.并在此基础上,定性分析了两寡头Cournot博弈的Nash均衡点及其稳定性,从中显示出在不同的市场参数下,对应不同的输电网运行状态：阻塞与不阻塞,市场会出现不同的Nash均衡点,甚至会出现没有Nash均衡点的情况;探讨了市场参数对市场稳定性的影响,提出了提高电力市场稳定性的措施;针对两寡头Cournot动态博弈模型,数值仿真出不同市场参数下市场的动态行为,其中着重探讨了当市场参数超出Nash均衡点稳定域后,展现出的周期甚至混沌的动态行为.     

A dynamic replicator model of the players’ bids in an oligopolistic electricity market

In this paper, the replicator dynamics of the power suppliers’ bids in an oligopolistic electricity market are derived for both the fixed and variable demand cases. The replicator dynamics stability analysis is also performed. The dynamics of the electricity markets are the results of players’ decisions. The physical parameters of the power systems (such as the lines capacities, voltage limitations, etc.) also affect the market dynamics indirectly, through the changes in players’ behaviors. Assuming rational players, an optimal bidding strategy for constructing the supply function (SF) of a generating firm is presented and based on that, the dynamics of the bid replicators are studied. Both fixed demands and price sensitive demands are taken into account. The replicator model is presented in the well-known state space structure. A case study is presented to show the applicability of the developed dynamic replicator bid model, and also to show how the Nash–SFE equilibrium evolves over time.     

碳市场背景下发电商竞价策略及电力市场均衡分析

碳市场交易提高了传统化石能源机组的发电成本,进而影响其在电力市场的竞价行为,电力市场均衡也随之发生改变。文章针对碳市场背景下的电力市场均衡问题建立了双层均衡模型,上层模型为考虑碳成本的发电商最优竞价模型,下层模型为考虑碳配额总量约束的电力市场出清模型,通过最优性条件理论以及二进制展开法、大M法等线性化手段将双层模型转化为混合整数线性规划,基于PJM 5节点系统,求解了多市场环境下有无碳市场的电力市场均衡,分析了碳市场对电力市场均衡状态的影响;同时,基于碳配额总量对电力市场均衡的灵敏度分析发现碳配额总量需适度收紧才能最大程度实现电力低碳减排作用。     

A coevolutionary approach to analyzing supply function equilibrium model

This paper presents a coevolutionary approach to analyzing supply function equilibrium (SFE) models of an oligopolistic electricity market. Both the affine supply function model and the piece-wise affine supply function model are considered. Different parametrization cases of the affine supply function model are analyzed. The piece-wise affine supply functions that have a large number of pieces are used to numerically estimate the equilibrium supply functions of any shapes. Simulation cases of the piece-wise affine supply function model with different peak loads, nonquadratic and nonconvex costs, and different demand elasticities are studied. An example based on the cost data from the real-world electricity industry is used to validate the approach presented in this paper. Simulation results show that the coevolutionary approach rapidly converges to SFE in the affine supply function model simulation and robustly converges to SFE in all cases of the piece-wise affine supply function model simulation. The approach is robust and flexible and has the potential to be used to solve the complicated equilibrium problems in real-world electricity markets.     

电量与备用共同市场的SFE模型分析

电力系统运行的技术特点要求足够的备用容量。一些电力市场采用单独的容量市场获取备用容量,这增加了发电企业竞标的复杂性。文中介绍了一种电量与备用共同竞价的日前集中拍卖市场设计。在这种市场方案中,系统运行机构可通过单一市场在日前获得足够的调用出力和备用容量。建立了发电企业在电量与备用共同市场规则下策略竞价的供给函数均衡(SFE)模型,分析了其市场势力对两种市场的影响。研究表明,与单纯电量市场相比,电量与备用共同市场在获取足够备用容量的同时,不会增加系统支付费用,实际上电量支付费用还会有所减少,而市场出清电价会略有降低。最后采用发电企业完全对称性假设,给出了不同企业数目情况下的算例结果。     

Impact of the Transformer Tap-Ratio Control on the Electricity Market Equilibrium

In this paper, the primal-dual nonlinear interior point method has been used as a basis for the derivation of a novel supply function equilibrium (SFE) algorithm for modeling the strategic interactions in the electricity market, using the ac network model, which incorporates modeling of the transformer tap-ratio control. The algorithm is used to investigate the impact of transformer tap-ratio control on the electricity market equilibrium and the effect of the interactions between network constraints and transformer tap-ratio control. The interior point social welfare optimization problem is combined with the optimization problem for maximizing the profit of each strategic generating firm in the market. The final combined single-level SFE problem is solved iteratively based on solution techniques of the interior point method. Numerical examples illustrate the effect of network constraints and especially the impact of transformer tap-ratio control on market equilibrium.     

发/供电公司市场均衡及竞价策略

在批发竞争的电力市场中,不仅发电公司要竞价上网,而且供电公司也要竞价购电。文中给出了批发竞争电力市场模式下发电商和供电商竞价模型,推导出了完全信息情况下发电商和供电商最优竞价策略的解析解,并用协同进化算法模拟了此模式下考虑功率约束时市场的运营,求得了市场均衡。通过算例说明了所提出算法的有效性,其结果表明市场均衡状态下发／供电公司竞价策略即为它们的最优报价策略。     

考虑跨时段负荷响应的电力市场多时段均衡分析

在电力市场环境下,用户负荷对价格的响应具有跨时段的特性。在计及输电约束的基础上,建立了一个考虑跨时段负荷响应的电力市场多时段线性供应函数均衡模型。该均衡问题是一个具有均衡约束的均衡问题(EPEC),可采用非线性互补方法求解。给出的算例证明了模型的合理性,表明跨时段负荷响应的引入可以缓解由于输电阻塞造成的用电不合理分配,并且能有效抑制发电商的市场力滥用。     

计及输电约束的线性供应函数激励显示机制

基于博弈论中的机制设计理论和线性供应函数均衡(LSFE)理论,设计了一种激励相容的线性供应函数激励显示机制。依据该机制,所有发电商的最优报价策略为呈报其真实的边际成本曲线;所有用户的最优报价策略为呈报其真实的边际效用曲线;而且参与者(发电商和用户)是否披露其真实的经济信息与输电约束及其他所有参与者的报价策略无关,即所有参与者披露其真实的经济信息为市场惟一的纳什均衡,且该均衡为占优战略均衡。从而,独立系统运行员(ISO)根据参与者的报价曲线实施经济调度,以实现电力资源的优化配置和社会福利的最大化。不仅从理论上论证了所提出的激励机制的合理性,而且以IEEE3机9节点电力系统为例进一步验证了该机制在限制市场势力和提高电力系统运行效率方面的有效性。     

电力市场均衡模型述评

传统的电力系统运行模型缺乏对参与者市场行为的考虑,不适应于新的市场环境,需要结合市场的竞争性研究电力市场的建模问题.对电力市场均衡模型在国内外研究的进展进行了较为全面的总结.对两类常用的电力市场模型Cournot模型和供给函数均衡模型,从应用领域到求解方法进行了评述.总结了两类模型在分析市场不完善性、市场仿真以及风险分析等方面取得的成果,指出了均衡模型存在的缺陷和改进的方法,充分考虑发电公司的市场行为,提高假设条件的准确性和模型的实用性.     

考虑合约交易的电力寡头垄断市场均衡分析

应用经济学中的博弈理论建立Cournot市场模型,推导了考虑合约的电力寡头垄断市场的均衡解,通过分析表明,合约的存在能够使市场更有效率,并且期权合约对于市场参与者来说更具有灵活性和吸引力.     

燃料市场对采用不同能源和技术的发电集团博弈策略影响

在解除管制的市场环境中,上游燃料市场和下游电力市场存在博弈关系。从长期来看,上下游市场的博弈关系反映了各市场主体的发展趋势,厘清关系能够为制定合理政策提供科学依据。在无容量约束的理想情况下,博弈关系较为简单,认识较清楚,但当存在发电容量约束,特别是容量约束发挥作用时,博弈关系将变得十分复杂。为此,文中基于建立的上下游市场博弈模型,采用数学分析的方法,以具有低热耗率发电技术的高效率电力集团容量约束为例,对具有不同技术特征电力集团之间及与燃料集团的博弈关系进行了定性分析,并通过仿真方法反复模拟博弈过程,验证了分析结果。研究结果表明,发电容量约束将打破理想情况下上下游联合博弈市场的纯策略均衡状态,形成软约束和硬约束两种不同均衡状态。     

考虑系统运行不确定性的电力市场均衡模型

电力系统运行与规划过程中存在众多不确定性因素,这给电力市场分析带来挑战.针对负荷不确定性与随机线路故障停运,建立了考虑系统运行不确定性的电力市场线性供给函数均衡模型.在该模型中,通过枚举所有可能的系统运行场景来处理不确定性因素.由于各系统运行场景的出现概率不同,发电厂商在各系统运行场景的收益不尽相同,因而面临相当大的决策风险.针对随机市场博弈的特点,扩展改     

Optimal bidding strategies in oligopoly markets considering bilateral contracts and transmission constraints

In electricity industry with transmission constraints and limited number of producers, Generation Companies (GenCos) are facing an oligopoly market rather than a perfect competition one. Under oligopoly market environment, each GenCo may increase its own profit through a favorable bidding strategy. This paper investigates the problem of developing optimal bidding strategies of GenCos, considering bilateral contracts and transmission constraints. The problem is modeled with a bi-level optimization algorithm, where in the first level each GenCo maximizes its payoff and in the second level a system dispatch will be accomplished through an OPF problem in which transmission constraints are taken into account. It is assumed that each GenCo has information about initial bidding strategies of other competitors. Impacts of exercising market power due to transmission constraints as well as irrational biddings of the some generators are studied and the interactions of different bidding strategies on participants’ corresponding payoffs are presented. Furthermore, a risk management-based method to obtain GenCos’ optimal bilateral contracts is proposed and the impacts of these contracts on GenCos’ optimal biddings and obtained payoffs are investigated. At the end, IEEE 30-bus test system is used for the case study in order to demonstrate the simulation results and support the effectiveness of the proposed model.