【作者】 张芳；

【导师】 杨以涵； 鲍海；

【作者基本信息】 华北电力大学 ， 电力系统及其自动化， 2012， 博士

【摘要】 输电成本是制定输电电价的基础,只有弄清输电成本特性才能制定出科学合理的输电电价。输电成本中网损和阻塞费用只占输电总费用的很小部分,但它与电网实际运行状况紧密相连,对于提高输电定价的有效性以及引导输电用户合理利用输电资源具有重要作用。这部分费用与系统物理潮流密切相关,不能采用财务方法进行分摊,必须在掌握电网潮流分布的物理本质后再附加具体的经济原则来进行公平合理的分摊。在确定的电力网络断面潮流下,形成电力网络的等值电路网络。通过经典电路理论进行严格的数学推导得到电源电流分布系数,此分布系数是一个无量纲的比例值,只由电力网络的运行(接线)方式以及电网中的设备参数决定。通过此分布系数和电源电流可直接确定各个电源在支路中的电流分布情况,进而提出了基于电源注入电流的潮流追踪方法,从物理层面上明确了功率的来源,通过理论和算例证明追踪结果完全符合电路基本定律。该方法无需将网络等值为无损网,完全基于经典电路理论,不需要作任何近似假设,反映了系统潮流的物理分布情况,而且该方法计算量小,容易具体应用。这是本文分析输电成本的物理基础,也是分摊阻塞费用时计算阻塞消除前后潮流变化量的依据。对于双边交易模式的潮流追踪,本文首先将双边交易功率等效成电流源,并将其引入节点电压方程,以此为基础推导出交易电流在网络中的分布系数,确定各交易的电流分布,进而可以明确支路上各交易的功率份额。电力市场开放后,各市场成员公开、公平地使用电网资源,增加了电网阻塞的机会。阻塞管理不只是消除阻塞,还必须对阻塞费用进行分摊,促进输电网的有效使用,从而减少阻塞的发生。在阻塞费用分摊之前,本文先分析了阻塞产生的物理成因,从而确定了各市场成员对阻塞的责任。在此基础上提出了基于电源注入电流的潮流追踪的阻塞费用分摊方法。该方法分两步实现阻塞费用的分摊,首先利用边际微增混合费用法将阻塞费用分摊给各阻塞线路,以线路边际微增混合费用与总阻塞成本的比值作为惩罚因子,将阻塞费用在线路间分摊时产生的不平衡分量分摊到各阻塞线路中,实现盈亏平衡。然后根据阻塞消除前后各市场成员在阻塞线路上的功率变化量,把该线路的阻塞费用分摊给联营交易模式的各个电源、负荷和双边交易模式的各个交易。由于各线路上的潮流变化量即为各电源在线路上潮流变化量之和,该方法分摊阻塞费用过程中不会产生任何交易盈余,而且体现了“谁用谁付,多用多付”的原则。以往的输电成本分析方法及输电定价方法都是利用网损去修正发电报价,结算时发电商用修正电价去结算,更多的关注可变成本的分摊,而系统中真正产生多少网损费用,每个电源产生的网损费用又是多少,很少有学者去重视。本文认为把网损费用隐含在修正电价中,既不利于系统运行机构了解系统的运行状态,也不利于各市场成员掌握自己的运行费用,应当在可变成本分摊的同时明确地计算出系统的可变成本和各电源的可变成本。因此,本文根据市场成员对阻塞的影响程度将阻塞费用分摊至各市场成员后,又将阻塞费用折算为每个电源的单位阻塞成本。基于支路费用守恒原则和节点费用守恒原则,计算出电源在网络中计及网损和阻塞费用的各节点单位成本,在此基础上建立了计及网损和阻塞费用的各电源及系统的可变成本模型,使用该模型可以计算出整个电网的可变成本以及每个电源向系统输送功率的可变成本。更多还原

【Abstract】 Transimission cost is the basis of the electricity price. The scientific and reasonable electricity price is maden after the characters of transimission cost are be clarified. The congestion cost and transimission loss accounts for only a small portion of the total cost of transmission cost. But it is closely connected with power system power state, it has a significant role to improve the effectiveness of transmission pricing and to help transmission user rationally using transmission resources. This part of the costs closely relates to the physical power flow.It cann’t be allocated using financial methods and it should be allocated according to the additional specific economic principles after the physical nature of the power flow distribution is clear.In the premise of the determining power flow of the power system, this paper can get the equivalent circuit network of the power system. According to the classic circuit theories, by mathematical reasoning the current distribution coefficients of the power supply are obtained. The distribution coefficients are decisied only by the power network operation mode (wiring) as well as the network device parameter. The contribution of branches and loads current supplied by every power supply can be obtained through the distribution coefficients. Then based on the current supplied by every power supply this paper puts forward a power flow tracing method.The power flow distribution can be physically defined. In this paper, the method is proved by Kirchhoff’s Current Law and power conservation theorem. Without any assuming, the network needn’t be equivalent to a lossless network.The method is simple and has small calculations. This is the basis of the transimission cost analysis considering the congestion cost in this paper. In bilateral mode,the bilateral transactions are described as current supplies.Based on the nodes voltage equation, the current distribution coefficients of the transaction current are obtained.According to the coefficients the usage of the branches by the transactions can be obtained and the transimission loss can be allocated to the transactions.In the open electricity market, the electricity business free biding increased congestion opportunity.Congestion management is not only to eliminate the congestion, but also the to allocate the congestion cost.So congestion management can promote the effective use of power system, thereby reduce the congestion opportunities. Before the allocation of congestion costs, this paper first analyzes the congestion resulting from the physical causes, which identifies the congestion responsibility of each market member. Based on the power flow tracing this paper puts forward a congestion cost allocation method. The method includes two steps to achieve congestion cost allocation. First the congestion cost is allocated to congested branches according to marginal mixed incremental cost. Because the power system is nonlinear, it exists the imbalance congestion cost while allocating the congestion cost. The imbalance congestion cost shall be allocated to the congestion branches according to the proportion of marginal mixed incremental cost. Then the power distribution of every branch and load provided by each power supply (transaction) is calculated based on the power flow trancing, considering the active power and reactive power. The power flow change of each power supply in each congested branch can be calculated, and the congestion cost of congested branch is allocated to each power supply (transaction) according to the power flow change. Because of the sum of all the lines power flow change of each power supply is equal to the lines power flow change,the congestion cost allocation method does not produce any trade surplus.And the allocation reflects the principle that is" who use who pay, use much and pay more".The transmission losses are used to correcting quoted price and the variable costs alloction is focus in the other transimission cost allocation methods.But the reachers do not pay attention to how many are the loss costs and the power supply costs.It is the disadvantage of the acquaintance of the system operator to the system running and the understanding of the power supply to the transmission cost.In this paper, the variable costs of the system and the power supply are calculated and allocated. Therefore, after the congetion cost are allocated to the market members according to the influence for the congestion of each market member, each power unit congestion cost is also calculated. Based on branch cost conservation and node cost conservation, this paper calculates unit cost of the power supply at each node considering network loss and congestion cost. The variable cost model of the power system and every power supply considering network losses and congestion cost is established.The model can calculate the entire network variable cost and each power supply to the system output variable cost.更多还原