Reactive power pricing and management

This paper explores the technical and economic issues of determining reactive power pricing structures in an open-access environment. It is believed that reactive power pricing and management under open-access will depend upon two important developments: (1) the functional unbundling of facilities that support the reactive power and voltage control service, and (2) grid rules to facilitate the coordination between generation and transmission systems for reliable system operation. The paper discusses the characteristics of reactive power that must be considered in order to develop a framework for reactive power pricing and management. Several cost allocation methods for valuing reactive power are presented. Two workable reactive power pricing structures are also proposed. The first is based on performance standards and the second is based on the local reactive power market concept     

Reactive power pricing structure for hydroelectric power station in condenser mode operation

Reactive power support is critical for system security and pricing of reactive power is a vital issue in restructured environment. Peaking units at hydroelectric power plant in condenser mode operation can provide major reactive power support. Therefore costing structure for hydroelectric power plant incorporating various cost components in condenser mode operation is presented in this paper. Major cost components include capital cost component, changeover cost component and a cost component related to number of service hours in condenser mode operation. A methodology is proposed based on these components. A case study of Koyna Hydro Electric Power Plant (KHEPP) is elaborated.     

基于OPF的实时无功电价及其分析

提出一种新的计算无功价格模型。在模型中引入静止无功补偿器(SVC)的生产成本,以丰富模型涵盖的经济信息。采用互补条件形成新的无功电价模型的Lagrange函数,详细分解实时电价模型,全面分析La-grange乘子λp、λq的经济意义,揭示出无功生产费用和经典经济调度的关联性。在IEEE-14节点系统上,针对不同负荷进行数字仿真,结果表明:SVC对系统无功定价产生积极影响,这说明所提模型的有效性。在更为广泛的系统IEEE-4—IEEE-118上的数字仿真表明:运用原始-对偶内点法(PD IPM)求解无功价格具有良好的鲁棒性。     

基于OPF的实时无功电价及其分析

提出一种新的计算无功价格模型.在模型中引入静止无功补偿器(SVC)的生产成本,以丰富模型涵盖的经济信息.采用互补条件形成新的无功电价模型的Lagrange函数,详细分解实时电价模型,全面分析Lagrange乘子λp、λq的经济意义,揭示出无功生产费用和经典经济调度的关联性.在IEEE-14节点系统上,针对不同负荷进行数字仿真,结果表明:SVC对系统无功定价产生积极影响,这说明所提模型的有效性.在更为广泛的系统IEEE-4-IEEE-118上的数字仿真表明:运用原始-对偶内点法(PDIPM)求解无功价格具有良好的鲁棒性.     

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.     

Product-specific moisture levels: A conceptual framework

An improved schedule to evaluate surface-mount technology popcorn jeopardy based on physics of moisture absorption is proposed. Key features are: 1) each lettered level implies a certain performance irrespective of package thickness (i.e., no penalty for thinner packages); 2) each successive level has stepped moisture concentration at the interior (i.e., clear stepped discrimination between levels); and 3) the time required for preconditioning is substantially reduced from current practice and an acceleration factor can be clearly computed.     

用于电能计量芯片的无功功率计量方法

现有电能计量芯片中无功功率计量电路难以同时满足计量精度高与硬件开销小的要求。为解决此问题,提出了一种无功功率计量的新方法,该方法采用3个一阶IIR滤波器,其中电压通道内的相位移动滤波器使电压信号产生-90°相移,电压通道和电流通道内的两个幅度补偿滤波器共同对由相位移动滤波器产生的信号幅度衰减进行补偿。两个幅度补偿滤波器被要求设计成具有相同的结构和参数,二者的并联应用不会改变电压与电流之间的相位差。提出了高效的无功功率计量系统设计方法,其中特别是幅度补偿滤波器设计的优化方法。仿真和实际产品测试结果表明,该无功功率计量方法不仅硬件资源消耗较少,而且可以达到较高的计量精度,优于现有电能计量芯片的无功功率计量方法。     

一种改进的无功定价方法

推导了一种负荷对线路潮流贡献分量的新算法。在分析系统无功生产成本构成的基础上,根据边际成本理论将无功生产成本分配给电网各线路,再根据负荷对线路的无功使用份额将各线路分担的无功生产成本分配给各个负荷,从而得出了各负荷分担的无功生产成本和相应的无功价格。该方法在确定负荷对线路无功使用份额时计及了P-Q间的耦合作用,无需任何假设或近似。不仅能够确保收支平衡,而且能为用户提供有效的经济信号。仿真结果验证了该方法的合理性和有效性。     

An annual framework for clustering-based pricing for an electricity retailer

In the competitive environment, it is necessary for a retailer to increase his/her profit as much as possible. There are few researches focused on the subjects related to the retailer and the retail market. In addition, those researches have mostly focused on the participation of the retailer in the wholesale market. In order to determine the optimal selling price, the knowledge of how and when consumers use electricity is essential to the retailer. This type of information can be found in load profiles of customers. In this paper, an annual framework for optimal price offering by a retailer is proposed which is based on clustering technique. For this purpose, load profiles of customers are used as their consumption patterns. Also, a profit function is defined as the objective of optimization problem based on the load profile considering conditional value at risk (CVaR) for risk modeling. Also, a new acceptance function is proposed to overcome drawbacks of the traditional ones. The objective function is a mixed-integer nonlinear problem which is solved by GAMS software.     

不平衡电流无功补偿方法研究

在对三相四线制系统几种特殊情况分析的基础上,应用叠加原理,采用星形和三角形两种接线方式组合,得出一般三相不平衡负载平衡化无功补偿公式,可消除不对称负荷产生的负序和零序电流分量,保持系统对称。该公式既适合于三相三线制系统,也适合于三相四线制系统。仿真结果表明,该补偿方法对于不同接线方式的不平衡负荷都具有较好的补偿效果,证明了理论推导的正确性。     

A framework for PSS pricing as an ancillary service in a competitive electricity market

This paper presents a new framework for the valuation of small signal stability as an ancillary service through Power System Stabilizers (PSSs). PSSs can improve small signal stability and simultaneously reduce the generation costs in a competitive market. This saving could be treated as a source to compensate the service provided by PSSs. This paper proposes an allocation approach to compensate the PSSs, proportional to their effectiveness in overall system small signal behavior. NSGA-II approach is used to solve the resulting multi objective optimization problem. A test system is used to represent the effectiveness of the proposed method.     

Application of auctions as a pricing mechanism for the interchangeof electric power

The expected move to a market-based electric power industry will significantly change electric utility operations. These changes will fundamentally alter the pricing of electric power. How this pricing will be accomplished is a key issue. Traditionally, embedded cost based methods have been used. Spot-pricing has received attention as a possible approach in a market-based electric power environment. Another market-based approach is the use of auctions. This paper presents the application of a sequential sealed-bid and sealed-offer auction to the pricing of electric power by using linear programming     

Utility-cogenerator game for pricing power sales and wheeling fees

The authors have studied an extensive game model of an electricity market where a cogenerator sells excess electricity to an electric utility or to an end user. They found that a buy-back system (the utility purchases cogenerated power) is as efficient as a cogenerator-customer wheeling system and that these two systems are more desirable than a monopoly system for the regulator. The buy-back rate should be equal to (LP bargaining solution) or less than (Nash bargaining solution) the marginal cost of the electric utility. They also conducted an analysis of a two-period electricity market in which they found that the cogenerator that can supply excess power during peak period obtains the market advantage     

输电阻塞情况下电能计价的LMP方法

随着电力市场改革的深入,输电阻塞成为电力系统中常见的问题。通过5节点电力系统示例分析了LMP方法用于阻塞情况下电能市场计价和系统结算的过程,并介绍了这种方法的应用情况。     

多场景下含风电机组的配电网无功优化的研究

研究了多场景下含风电机组的配电网无功优化问题。利用概率统计的思想解决了风电机组有功输出的不确定性问题,根据转子侧最大电流限制条件确立了风电机组无功输出范围。结合传统的电容器无功补偿方法,将风电机组作为连续可调无功源参与到配电网的无功优化。建立了以系统网损最小和节点电压越限惩罚为目标的无功优化模型。算例表明不同场景下的风电机组参与配电网无功优化可有效地降低系统的网损,提高各节点电压,同时,增强配电系统受风速影响的适应性。     

电网无功补偿技术及发展动向

电力系统网络元件及负荷的阻抗主要是电感性的 ,如 :变压器、输电线、异步电动机以及大多数家用电器。这些负荷的自然功率因数约为 0 .6～0 .8,如果不对其进行无功补偿直接接入电网 ,用电负荷所需无功功率全靠发、配电设备经长距离传送供给 ,势必加大电网负载、电压降和线路损耗 ,因此一般常用电容器作无功补偿。1　我国电容器无功补偿装置的发展经历阶段1 .1　 70年代初期 ,参照前苏联引进的电容无功补偿装置 ,我国第一代电容无功补偿装置由刀熔开关和电力电容器构成 ,电容器投切完全依靠手动 ,该阶段装置仅适用于无功功率比较固定的场合。…     

Management procedures for pricing and expense allocation of renewable energy generation published

On December 21, 2005, the State Council issued the Interim Provisions for Promotion of Industrial Structure Readjustment, and the National Development and Reform Commission published the Guiding Catalogue of Industrial Structure Readjustment. This catalogue has drawn up a route chart for the structural reform of power industry, According to the interim provisions, key points of Chinese power industry development are as follows. First, to optimize and develop coal-fired power generation taking large efficient unit as a core; second, to orderly exploit hydropower; third, to actively expand nuclear Dower： fourth, to enhance Dower grid configuration; fifth,     

风电场并网运行的无功补偿优化问题

风电场的功率输出具有很强的随机性,对风电场运行后的无功优化和系统稳定性问题进行了探讨。采用基于约束规划的无功补偿模型,提出基于随机模拟技术和Beta分布的粒子群优化解算方法。论述了Beta分布的粒子群算法的关键实施技术(Beta分布函数、初始可行解的产生策略、粒子的更新策略)及具体优化解算过程,并采用风电场并网运行的无功补偿优化及风电场并网运行的稳定性校验实例,表明该模型能满足可靠性和经济性条件下风电场所需的补偿容量,所采用的解算方法效果好。     

配电网的无功功率及无功功率补偿

对10kV配电网中的无功进行了分析，介绍了无功补偿的原理、无功补偿装置容量的确定及其安装方法，并通过具体实例说明安装无功补偿装置带来的收益。     

面向电网运行方式计算的不收敛潮流无功调整方法

潮流收敛调整是电网运行方式计算的重要工作,其中无功安排不合理是潮流不收敛的重要原因之一。由于无功问题非线性较强,凭借人工经验进行调整较为困难。为此,提出了基于自适应Levenberg-Marquardt的不收敛潮流无功调整方法,将原始问题分解为序列二次规划形式的有功子问题和无功子问题,引入自适应阻尼因子。利用增广拉格朗日函数及信赖域方法决定是否接受迭代步长的更新。详细分析了所提方法能够提升数值稳定性的原因。通过对IEEE300节点系统、波兰3375节点系统以及某省级电网实际系统的算例分析表明,所提方法能够给出无功调整的最小二乘解以实现潮流收敛,进而为方式人员进行潮流调整提供参考和借鉴。