高压区域电网分层分区方法的研究

发布时间：2018-04-12 08:33

本文选题：短路电流超标 + 电网分区　；参考：《华北电力大学》2017年硕士论文

【摘要】：随着国民经济的发展,电力系统的容量不断增大,我国一次能源基地与能源需求地区呈远距离逆向分布的特点,需要远距离大容量输送电能。为保证电能输送的经济性和安全可靠性,传统的解决方法是升高系统的电压等级。电力系统在一个新的更高电压等级问世早期,网架结构上不可能做到非常完善,为保证较大的传输功率,产生了电磁环网,电网合环运行致使短路电流增大。同时,为应对电力市场化的发展,主网架的输电能力和可靠性也应向更加完善的方向发展。针对短路电流超标严重的情况,研究了电网分层分区模型、区间联络线选取方法、大电源接入电网接入点选取等问题,给出了新的电网分区方法,大电源接入电网接入点选取方法,为解决短路电流超标问题提供了新的思路。考虑到传统电网分区方法未充分考虑电网结构的不足,本文从分层分区的角度出发,以500kV网架为主干网架,提出了基于改进汽车接力模型的电网分区新方法,该方法无需进行大量的数学运算,通过编程进行路径的搜索,寻找距离初始站电气距离符合要求的站点,进而进行分区划分。电网分层分区运行后,当某一分区因元件故障产生区域功率缺额时,分区间通过联络线提供功率补给或负荷转移是解决功率缺额的重要措施,与此同时,区间联络线既保证了分区间的联系,又可有效避免连锁故障的发生。因此,区间联络线的选取至关重要。本文针对区间联络线的选取进行了研究,提出了一种基于相对熵组合赋权法的区间联络线选取的评估体系,综合考虑了短路电流、潮流转移、整体潮流水平、节点电压稳定性、短路容量等指标,保证了评价的完整性与合理性。现有大电源接入电网接入点的确定方法,主要借助于专家经验,主观依赖性过大,本文构建了较为完整的适用于评价大电源接入点选取合理性的指标体系,该指标体系考虑了系统潮流分布、短路电流、N-1故障、稳定性、网损等多项指标,使评估效果更具有合理性。同时,本文确定综合权重的方法为组合赋权法,避免了单一赋权法确定权重时存在较大的主、客观性,然后利用基于综合权重的改进灰色关联分析法对大电源接入点选取方案进行综合评估,从电网规划角度考虑,为大电源接入电网接入点的选择提供了一个切实可行的方法。最后利用PSD电力系统分析软件对唐山电网数据进行实例仿真分析,仿真结果同样也论证了该评价指标体系的完整性与该评估方法的合理性。
[Abstract]:With the development of the national economy, the capacity of the power system is increasing. The primary energy base and the energy demand area in our country are distributed in a long distance and reverse, which requires a long distance and large capacity to transmit electric energy.In order to ensure the economy and safety of power transmission, the traditional solution is to increase the voltage level of the system.In the early days of a new higher voltage level, the grid structure could not be very perfect. In order to ensure the large transmission power, the electromagnetic loop network was generated, and the short circuit current increased due to the closed loop operation of the power network.At the same time, in order to cope with the development of electricity market, the transmission capacity and reliability of main grid should be more perfect.In view of the problem that short-circuit current exceeds the standard seriously, the paper studies the model of power grid hierarchical partition, the method of selecting interval tie-line and the selection of access point of large power supply, and gives a new method of power grid partition.The method of selecting access point for large power supply provides a new way to solve the problem of short circuit current exceeding the standard.Considering that the traditional power grid partition method has not fully considered the shortcomings of the power network structure, this paper presents a new method of power grid partition based on the improved automobile relay model from the point of view of hierarchical partition and taking the 500kV grid as the main network frame.This method does not need to do a lot of mathematical operations, through programming to search the path to find the electrical distance from the initial station to meet the requirements of the station, and then partition.After the operation of the power grid in stratified and partitioned areas, it is an important measure to solve the power gap by providing power supply or load transfer through the tie-line in a certain area because of the component fault, and at the same time,Interval tie-line can not only guarantee the connection of sub-interval, but also effectively avoid the occurrence of cascading faults.Therefore, the selection of interval tie-lines is very important.In this paper, the selection of interval tie-lines is studied, and an evaluation system of interval tie-line selection based on relative entropy combination weight method is proposed, which considers short-circuit current, power flow transfer, overall power flow level and node voltage stability.Short circuit capacity and other indicators ensure the integrity and rationality of the evaluation.The existing methods for determining the access point of large power supply to the power network mainly rely on expert experience and have too much subjective dependence. This paper constructs a relatively complete index system suitable for evaluating the rationality of the selection of large power access points.This index system takes into account the system power flow distribution, short circuit current N-1 fault, stability, network loss and so on, which makes the evaluation effect more reasonable.At the same time, the method of determining the comprehensive weight in this paper is the combination weight method, which avoids the larger subjective and objectivity when the single weight method is used to determine the weight.Then, an improved grey relational analysis method based on comprehensive weight is used to evaluate the selection scheme of large power access points. From the point of view of power network planning, it provides a feasible method for the selection of access points for large power sources.Finally, the simulation analysis of Tangshan power network data is carried out by using PSD power system analysis software. The simulation results also demonstrate the integrity of the evaluation index system and the rationality of the evaluation method.
【学位授予单位】：华北电力大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM732

【参考文献】