Marginal transmission pricing and supplemental cost allocation method: A case of Philippines

The paper presents application of marginal cost-based pricing of transmission services which is based on the use of bus incremental cost, in a real network of Philippines, and investigates the relationship between marginal network revenue and the transmission utility's (Transco) revenue requirement. The network income derived from marginal cost pricing fell below Transco's revenue requirement thus necessitating for supplementary charges. The paper proposes an allocation method that allocates supplementary charges based on the user's contribution to incremental flow. This method is applied to allocate the remaining network costs not covered under marginal pricing, and the results are compared with the traditional postage stamp method.     

实时电力交易中平均成本和边际成本定价理论研究

发电计划的制定、网损分摊以及阻塞调度是实时电力交易的主要内容。首先对电力市场均衡进行了详细的描述,阐明了基于市场均衡原则的市场效益分配是公平、合理的;然后基于市场均衡原则分别论述了基于平均成本定价理论和边际成本定价理论的网损分摊以及阻塞调度方法,说明了以平均成本定价理论为基础的网损分摊方法是精确的,而基于边际成本定价理论的阻塞费用分配方法是有效的;最后以IEEE-30节点系统为检验系统,对所提出的方法进行了验证,证明是正确的。     

Considering system non-linearity in transmission pricing

In this paper a new approach for transmission pricing is presented. The contribution of a contract on power flow of a transmission line is used as extent-of-use criterion for transmission pricing. In order to determine the contribution of each contract on power flow of each transmission line, first the contribution of each contract on each voltage angle is determined, which is called voltage angle decomposition. To this end, DC power flow is used to compute a primary solution for voltage angle decomposition. To consider the impacts of system non-linearity on voltage angle decomposition, a method is presented to determine the share of different terms of sine argument in sine value. Then the primary solution is corrected in different iterations of decoupled Newton–Raphson power flow using the presented sharing method. The presented approach is applied to a 4-bus test system and IEEE 30-bus test system and the results are analyzed.     

Marginal pricing of harmonic injections

Proper valuation of harmonic injections and distortion is critical if an efficient solution is to be provided for any harmonic problem, which may exist. Indeed without proper tools to value harmonic distortion, it is not possible to quantify the extent of any problem. This paper demonstrates that it is possible to develop marginal prices for harmonic injections, which will accurately reflect the value of the injections to the rest of the network. Given an allocation of harmonic pollution rights these prices act to coordinate each member of the network to act in a globally optimal manner     

Assessment of transmission cost recovery applying marginal pricing in hydrothermal power systems

This paper describes an integrated framework to evaluate short-run marginal costs (SRMC) in hydrothermal systems, taking into account the chronological aspects of reservoir operation, transmission constraints, equipment failures, hydrological variation and load uncertainty. The resulting SRMC values are used to calculate circuit revenues, which are then compared with investment requirements. It is shown that the representation of these probabilistic factors substantially increases revenues, in contrast with the widely reported under-recovery found in studies which only represent normal operating conditions. Case studies with the Brazilian North-Northeastern system are presented and discussed.     

Long-run marginal cost based pricing of interconnected system wheeling

Each utility in an interconnected system has an obligation to guarantee sufficient transmission capability to maintain an efficient, economical, reliable and secure system during peak scenarios. Security is an important consideration underlying network investment. The standards of service have a direct impact on investment burdens and therefore definition and consensus among participants in respect of security standards are necessary. Charging for transmission services, ensuring the investment levels and recovery of sunk capital are new problems now receiving attention in the context of electricity supply industry unbundling. In this paper a method for long run marginal cost (LRMC) based pricing in multi-area interconnected system, based on the incremental use of each area's transmission network at times of peak flow, is proposed. The LRMC of transmission capacity is based on long term costs of transmission investment requirements. The marginal wheeling costs, with security taking into account, are computed using the sensitivities of the MW-mile of each area with respect to the bus power demand. These sensitivities are calculated using a linear expansion of the Kuhn–Tucker conditions of the investment cost optimization problem. Contingency ranking method is used to speed up the computation.     

输电网的拉姆齐定价研究

由于输电网具有长期规模经济性,基于最优潮流和节点电价(LMP)模型的输电阻塞电价收入不足以弥补输电公司的总成本.采用拉姆齐定价(Ramsey Pricing)模型对满足输电公司预算平衡约束条件下的以电力市场长期效率为优化目标的输电电价进行了研究,结果表明,输电公司主要通过向下扭曲输电容量或降低输电交易量来实现盈亏平衡,而输电的拉姆齐价格的变化与各节点的发电公司的供给价格弹性以及用户的需求价格弹性有密切关系.对一个3节点电网的算例分析结果验证了模型的合理性.     

国外输配电定价体系分析及其对构建新型输配电价体系的启示思考

针对我国省级电网现有输配电价中容量电费占比比较低,固定成本难以回收问题,研究新型电力系统建设背景下输配电电价体系问题。梳理了国外比较有代表性的英国、美国、法国等在完全电力市场环境下输配电电价体系,总结其特点和规律。在此基础上,结合构建新型电力系统的发展需求,分析构建以容量电价为基础的输配电价新体系的必要性,并以2021年度某省11个地级市大工业用户的电量数据为例,测算以容量电价为主的输配电价水平。测算结果表明,若实行容量电价,即使大量光伏并网,导致负荷水平下降,输配电成本仍然能够足额回收,对于我国省级电网输配电定价机制的设计具有参考意义。     

Improving high-voltage transmission system adequacy under contingency by genetic algorithms

The paper presents a methodology which can be used to improve the static adequacy of high-voltage (HV) transmission systems under contingency. In this case the most suitable actions to be taken for bringing the power system back to acceptable operation conditions are identified by means of a power system management software. The proposed software combines a micro-genetic algorithm (μGA) optimization procedure with a load-flow program based on the fringing current correction (FCC) method. The foreseen control actions consist in transformer tap setting, insertion and/or regulation (if variable) of shunt reactor and capacitor banks, change of network configuration, power re-dispatching and load shedding. The performance of the proposed procedure is tested with respect to the main parameters both of electrical power systems and of genetic algorithms (GAs). An application to existing HV transmission systems is presented and discussed in order to evaluate its possible use in a System Control Center.     

南水北调西线水电权转让定价的边际机会成本方法

南水北调西线调水入黄后,会增加黄河干流梯级电站的发电效益,同时也将减少调水河流长江上中游梯级水电站的保证出力、装机容量、年发电量等。西线调水使调水河流水力发电权流转到受水河流,水资源的电能价值随两线调水在两地水电企业间进行了重新分配。本文利用边际机会成本理论对南水北调两线工程的水力发电权转让价格进行了量化分析,提出了融容量成本、电量成本和环境成本为一体的水力发电权转让价格的定价方法。     

A method for optimal pricing of electric supply including transmission system considerations

Determining real-time electricity rate structures is currently receiving a great deal of attention. In this paper, a strategy for pricing electricity supply is formulated and evaluated. Unlike other methods which use only the variation of fuel cost for generation to estimate the rate structures, the proposed pricing algorithm incorporates the optimal allocation of transmission system operating costs based on time-of-use pricing. The transmission costs are obtained by assigning a price k to each unit of power flow in the network. The assignment does not discriminate between participants located at differing parts of the network. The real-time pricing reflects the instantaneous cost of production and functions as a load management tool because this interacts with consumer behavior. The demand for power flows and transmission on an electricity supply system, like the demand for any bundle of economic goods depends upon the assigned transmission prices, together with the economic benefit to the consumer. It is assumed that there are no privately owned generating plants and that all plants and transmission lines are operated by the utility. The modeling scheme is applied to the IEEE standard 5, 14, 30 and 57 bus power systems and involves solving a modified optimal power flow problem (OPF) iteratively using the MINOS package. It is concluded that the method has a wide potential application in electricity supply pricing.     

解除管制的电力零售市场实时电价研究

零售侧打破垄断引入竞争是电力市场发展的趋势,制定合理的零售电价是市场开放的关键.根据电力零售市场的特点,基于负荷价格响应的定义以及边际成本定价理论,推导出了考虑负荷价格响应的有功实时电价的表达式.以社会成本最大化为目标函数,建立了考虑负荷价格响应特性的最优潮流模型,从而求解出未来引入竞争的电力零售市场中电力库交易模式下的实时电价.采用32节点配电系统对所提方法进行仿真,结果证明为促进零售市场竞争、引导用户合理用电提供了合理有效的定价方法.     

Assessment of transmission congestion cost and locational marginal pricing in a competitive electricity market

In an open-access environment, transmission constraints can result in different energy prices throughout the network. These prices are, in fact, dependent on a number of factors such as the generating unit bid, system load level, network topology and security limits imposed on the transmission network due to thermal, and voltage and stability considerations. Computing these energy prices at all buses in large transmission networks under given system operating conditions can be time-consuming. This paper describes a simple methodology based on the analysis performed by the Hydro One in-house computer program (PROCOSE) to calculate, for a given period of time, transmission congestion cost (TCC) in dollars per unit time and locational marginal pricing (LMP) in dollars per megawatt-hour (MWh) at any selected bus in the transmission system. In addition, the information provided by the program output on congested transmission elements is used to identify buses in the network whose LMPs are representative of the entire network. The computed LMPs at these buses are used to define zones in the network where each zone has its LMP. The proposed methodology can be used to carry out sensitivity studies to determine the impact of changes in system parameters and operating conditions on the LMPs. The proposed method is illustrated using the IEEE Reliability Test System (RTS) and the Hydro One network system.     

集成定价法在输电电价中的应用

对输电电价的定价方法进行了研究,对输电网的成本进行了分析,将其成本分为固定成本和变动成本2大类,固定成本基本上不随时间变化,变动成本随时间变化而不断改变。提出了集成定价思想,即对输电网的固定成本采用综合成本定价法,按最大需量进行分摊,而对变动成本则采用基于边际成本定价法的实时电价并进行实时分摊,两者有效结合即得出输电网的电价模型。该模型可称为集成定价法下的节点电价模型,可以应用于实时电价、分时电价、日前市场电价和远期合同电价。通过算例说明了该电价模型的具体应用。     

风力发电CDM项目边际减排成本分析

CDM项目是基于发达国家温室气体减排义务之上的发达国家和发展中国家的合作机制。在分析发达国家和发展中国家边际减排成本的基础上,从经济学角度阐述CDM产生的原理。以风电场为案例,确定风电项目基准线和其所需的参数,计算该风电场的单位减排量成本,依次将基准线减排量、基准线项目单位发电成本和CDM项目年发电量对单位减排成本的敏感性做了分析。从宏观和微观经济实体2个角度,提出开发CDM项目的建议,得出单一因素难以对单位减排成本产生实质性影响的结论,并对我国目前CDM开发提出一些看法。     

Comparison of transmission pricing models

In this paper we make a comparison of three transmission pricing models: the Wangensteen model, the optimal power flow model and the Hogan model. The similarities among the models are that all can be used in locational pricing systems. In these systems the prices are calculated as the marginal cost that in turn equals the marginal benefit to load. In the Wangensteen model and the original optimal power flow model, the locational prices are equal to the Lagrange multipliers associated with the power flow equations. On the contrary, Hogan’s model and the modified optimal power flow model express the locational prices as equal to the reference bus (node) price, the marginal costs of losses, and the marginal costs of congestion. The Wangensteen model is used for educational purposes and considers elastic load. The optimal power flow model has been widely used in electrical engineering and dispatch of power systems. Load is assumed to be inelastic. Hogan’s model is an economist’s version of the optimal power flow model and considers elastic load. It also gives an expression for the locational prices in terms of an equilibrium equation.     

输电服务定价的研究进展

目前所提出的输电定价方法主要分为基于会计学的综合成本法和基于微观经济学的边际成本法。综合成本法能保证电网收支平衡和合理的利润，但它不包含任何经济学信息；边际成本法可提供丰富的经济学信息，但不能保证收支平衡。近年来出现了将两者结合的集成方法。简要介绍了这些方法的研究成果及其优缺点。此外，还粗略介绍了期货、期权理论在输电电价中的应用。     

Slack-bus independent penalty factor for regional spot pricing under deregulation

Recently, the deregulation has been a hot issue in electric power industries with the introduction of the bidding system to electric power markets. One of the main topics associated with the deregulation is spot pricing where the exact analysis of transmission loss and the method of calculating reliable penalty factor play an important role. Penalty factors calculated with conventional methods are highly dependent on the location of the slack bus, which brings about unfair competition to Independent Power Producers (IPPs). This paper presents a new method of calculating the exact and reliable penalty factor independent of the change of the slack bus. The proposed method is tested on IEEE 14 bus system, New England 39 bus system and OH-145 bus system. The test results show that the proposed method can give more reliable information of the penalty factors for the regional spot pricing.     

Forward contracts for the operation of an electricity industryunder spot pricing

A study is reported of the use of forward contracts as risk instruments for electricity industries operating under spot pricing. Forward contracts involve financial transactions or commitments which relate to a physical trade at a later time instance. Price setting and appropriate participant responses are discussed. Simulation studies are used to demonstrate that forward contracts offer participants an opportunity to reduce their risk exposure without removing the incentive to respond to higher spot prices     

A flexible decision method for transmission system expansion planning considering power interruption cost

Under the current deregulation of the electric utility industry, power system planning has become more complex. System planners are required to study how to use available resources to meet customer's demand economically with acceptable reliability and quality. Integrated resource planning has emerged recently as one effective approach for this problem, and the approach has been expanded to include the value of reliability, that is, power interruption cost. This paper is aimed at developing a flexible decision method to select a favorable plan among various transmission system expansion alternatives, not only from a power supplier's viewpoint, but also from the customer's perspective, including cost of interruption. Bellman-Zadeh's maximizing decision using a fuzzy decision set is applied as a flexible decision method which is able to reflect the planner's intentions. Numerical examples are given to ascertain the effectiveness of the proposed method.