【作者】 张耀先；

【导师】 王成山；

【作者基本信息】 天津大学 ， 电力系统及其自动化， 2003， 硕士

【摘要】 在完全竞争的电力市场中,所有的发电公司向电网公司卖电,所有的供电公司从电网公司购电。在仅开放发电侧的电力市场环境下,电网公司根据负荷预测数据和各发电公司的报价数据来决策经济的电力交易计划,并按照系统的边际购电价格向发电公司付款购电,发电公司则按照交易计划的结果安排所属发电机向电网供电。由于在进行电力交易计划的过程中,主要考虑的是电网的经济性,所以电网公司还承担着保证网络安全可靠运行的职责。系统输电能力的确定对于约束电力交易行为,保障公共电网安全具有积极的作用。系统输电能力的大小是电力市场环境下电力交易双方需要确切掌握的基本数据,它是指在特定的系统运行情况下互联的电力系统通过区域间所有联接线将电能可靠地由一个区域输送到另一个区域的能力。为了充分利用现有输配电系统,提高系统的稳定裕度,计算系统输电能力的算法应该尽可能地模拟系统的运行情况以求得最大的系统输电能力。电力系统本身是一个复杂的非线性动力系统,随着系统区域间功率交换量的增大,诸如Hopf分叉或鞍点分叉等非线性动力系统中的典型现象都可能出现,从而破坏系统的安全性。如何准确地确定在电压稳定性等复杂约束条件下的系统输电能力,成为了当今电力系统界所面临的急待解决的研究课题。目前求解系统输电能力的方法主要有两种:连续性潮流计算法(简称CPF法)和最优潮流法(简称OPF法)。本文重点讨论在静态电压稳定性约束下的系统输电能力计算问题。针对CPF法中发电机出力的增长方向通过预先设定的方式确定,与实际系统运行情况不相符合这一缺点,本文提出了根据短期交易计划中的机组组合和经济调度结果,确定出考虑电网经济性的发电机调度方式,然后利用连续性潮流计算程序完成给定发电机调度方式下的系统输电能力计算方法。如果按照经济性所确定的发电机调度方式,不能满足负荷增长要求时,则由最优潮流计算程序给出一个可使系统输电能力达到最大的发电机调度方式,以此来提高系统的输电能力,最大限度地满足负荷变化的要求。更多还原

【Abstract】 In the perfect power market, all the Generation Companies sell their outputs to the Grid Company, and all the Distribution Companies purchase their energy requirement from the Grid Company. In the generation-sided power market, the Grid Company makes economic decisions on the trade planning through the datum of load forecasting and Generation Companies’ bids. At the same time, the Grid Company purchases the Generation Companies’ outputs at the price of system marginal price. According to the result of trade planning, the Generation Companies arrange their generators to provide power to the grid. In the process of making decisions on the trade planning, the economy of the grid is considered chiefly, so the Grid Company is charged with assuring the secure and reliable operation of the grid. Confirming the power system transmission capability has good effect on restricting the actions of the trade and assuring the security of the grid.In the power market, the power system transmission capability is the basic data to both sides of the power trade. It is referred to the capability of transmitting power from one area to another area through all the transmission lines in given system operational environment. For making good use of existing transmission system and increasing the stability margin of the system, the method of calculating the power system transmission capability should simulate the operation of the system and calculate the maximal power system transmission capability.Power system is a complicated nonlinear dynamic system. Along with the increasing of power exchange amount between the two areas, the typical problems of nonlinear dynamic system, such as Hopf bifurcation and saddle-node bifurcation may appear, so the security of the system may be destroyed. How to calculate the power system transmission capability in complicated voltage stability constraint conditions exactly becomes a desirable study problem in the power system nowadays.Now the main methods of calculating the power system transmission capability are continuation power flow calculating method (CPF method) and optimal power flow calculating method (OPF method). The calculating problem of the power system transmission capability in constraint conditions of steady-state voltage stability is discussed in this paper. For the disadvantage differing from the practical operation that the increasing direction of the outputs of generators is confirmed through preestablished method, this paper presented a new calculating method. The fashion of generation dispatching considering grid economy is obtained from the result of unit commitment and economic dispatch of short-term trade planning in power market. Then the power system transmission capability is calculated in given fashion of generation dispatching using CPF program. If the increasing requirement of the load can’t be met using the fashion of generation dispatching considering grid economy, a new fashion of generation dispatching which can increase the power system transmission capability is produced using OPF program. So the power system transmission capability is improved, and the requirement of load change is met furthest.更多还原