Full AC analysis of value of DER to the grid and optimal DER scheduling

This paper presents part of the work ComEd and Quanta Technology have performed to quantify the locational and temporal value of DER to avoid distribution grid upgrade investments. It focuses on the formulation of a robust and efficient algorithm for DER optimal dispatch on a distribution feeder to mitigate the violation of current and voltage limits using the allocated cost of capacity and locational marginal value of real and reactive DER injection/withdrawal.     

Congestion management by determining optimal location of series FACTS devices using hybrid bacterial foraging and Nelder–Mead algorithm

In this paper, the Thyristor-Controlled Series-Compensated (TCSC) devices are located for congestion management in the power system by considering the non-smooth fuel cost function and penalty cost of emission. For this purpose, it is considered that the objective function of the proposed optimal power flow (OPF) problem is minimizing fuel and emission penalty cost of generators. A hybrid method that is the combination of the bacterial foraging (BF) algorithm with Nelder–Mead (NM) method (BF-NM) is employed to solve the OPF problems. The optimal location of the TCSC devices are then determined for congestion management. The size of the TCSC is obtained by using of the BF-NM algorithm to minimize the cost of generation, cost of emission, and cost of TCSC. The simulation results on IEEE 30-bus, modified IEEE 30-bus and IEEE 118-bus test system confirm the efficiency of the proposed method for finding the optimal location of the TCSC with non-smooth non-convex cost function and emission for congestion management in the power system. In addition, the results clearly show that a better solution can be achieved by using the proposed OPF problem in comparison with other intelligence methods.     

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。     

考虑了动态约束和稳定约束的最优潮流

电力系统最优潮流于1962年由法国学者J．Carpentier最先提出，至今已整整四十年了。在这过去的四十年里，最优潮流算法取得了很大的发展，获得了广泛的应用。在电力市场化的今天，如何满足人们对最优潮流日益增高的要求，是对最优潮流的严峻挑战；本文侧重从动态最优潮流(DOPF)、暂态稳定限制下的最优潮流(TSCOPF)、电压稳定限制下的最优潮流(VSCOPF)等方面介绍了最优潮流的最新发展。并指出了最优潮流今后在电力市场中的发展方向。     

二级备用辅助服务市场中可中断负荷管理模型研究

该文研究建立了二级备用(即非旋转备用，或称运行备用)容量辅助服务市场中的可中断负荷(以下简称IL)招标数学模型。电力市场运营管理机构可以采用这个模型对IL投标方案进行实时性选择。这个模型基于最优潮流(OPF)算法。该文也对IL市场结构进行了研究并提出了建议。模型包括了对IL招标方案设计要考虑的主要因素，例如，提前通知，负荷点的位置，负荷的功率因素，等等。通过实施可中断负荷管理(简称ILM)，ISO可以在电网高峰负荷时段拥有充足的运行备用容量。     

基于故障风险指标排序的安全约束最优潮流

安全约束最优潮流(SCOPF)是一种常用的电力系统运行调度方法,但由于需要考虑大量的预想事故,问题的求解十分困难。如何加快SCOPF的求解速度是现阶段研究的热点问题。在传统的基于故障严重度排序的安全约束最优潮流基础上进行改进,采用改进过载风险指标代替传统的严重度指标,并考虑电力网络实时的天气状况,提出了一种新型的基于故障过载风险指标排序的安全约束最优潮流算法。算例分析表明,该算法所采用的故障集更小,具有迭代速度快、安全性高和经济性好的特点,可为调度员的运行决策提供重要参考。     

基于混沌优化和BFGS方法的最优潮流算法

将混沌优化与拟牛顿法中的BFGS方法相结合，提出了一种新的混合优化算法，并应用该方法进行电力系统最优潮流的计算。混沌优化方法利用混沌运动内在的遍历性、随机性和规律性等特点，跳出局部最优解，接 近最优点；同时，利用BFGS方法在最优点的邻域内局部寻优，提高了收敛速度和求解精度。 通过对IEEE 14，30和57节点试验电力系统的数值计算，验证了算法的有效性。     

电力市场环境中常规潮流与最优潮流在网损分摊中的应用

潮流计算是电力系统最重要的运算之一,为此,通过算例对BX型快速解耦潮流和最优潮流进行了分析.算例使用基于合作博弈论中的核仁理论的网损分摊方法对这两种潮流计算方法所计算的网损进行了分摊,计算结果表明,采用最优潮流计算网损优于使用常规潮流计算网损,并且基于最优潮流的网损分摊结果更易于被市场成员接受.     

Influence of TCSC on congestion and spot price in electricity market with bilateral contract

This paper presents a quantitative analysis of the effect of TCSC on congestion and spot price in deregulated electricity markets. The paper could also be considered as a comprehensive tutorial on the influence of TCSC in electricity market. A voluntary pool market, where the market participants can trade electricity either via a pool or through bilateral contracts is considered. The electricity market is modeled in an optimal power flow framework with the objective of maximizing the social welfare. In such formulation, the Lagrange operators associated with the equality constraints associated with real power balance give the spot prices of energy at each bus of the system. Studies are carried out with and without TCSC at peak and low loading conditions to capture the influence and to see the effectiveness of TCSC at different loading conditions. The paper further explores the effect of TCSC compensation level on the spot prices and the congestion under varying pool and bilateral loading conditions. A 5-bus test system is used for numerical studies and to showcase the influence of TCSC in an electricity market environment.     

Hybrid approach for congestion management using optimal placement of distributed generator

Congestion management (CM) in a large power system network is a difficult task which can be solved by placing one or more distributed generators (DGs) on congested lines. The first concern is to determine the exact location of congested line for the placement of optimal size of DG so that cost can be minimised. In this work, hybridisation of firefly technique and differential evolution optimisation search has been proposed, which manages congestion effectively by rescheduling of generators satisfying the system constraints both technically and economically in the deregulated market scenario. To validate the proposed hybrid approach, results have been compared with firefly optimisation technique results. It is observed that the hybrid approach is an efficient tool in handling CM resulting in a secure operation to reduce flows in the heavily loaded lines with low system loss and increasing power capability with improved stability of network by controlling power flows in the network.