大电网建设时序的暂态安全稳定分析

发布时间：2019-01-03 20:08

【摘要】：电力系统是国民经济和社会发展的关键，随着社会的不断发展和经济技术的不断进步，工业和生活用电需求量不断增大，，人们对电能质量要求越来越高。目前我国电网已经形成大电网格局，随着特高压交直流技术的开展，对现有电力系统规划提出了新的挑战。在这种背景下，本文采用大电网建设时序进行电力系统规划。大电网建设时序与常规电力系统规划侧重点有所不同，提出了大电网建设时序综合评估指标体系。将首先介绍提出综合评估指标体系的意义和思路，并着重研究综合评估指标体系的暂态安全稳定指标。大电网建设时序暂态安全稳定评估包括优化过程中和后校验评估，优化过程中暂态安全稳定评估要求计算量小，因此本文采用结构均衡性作为优化过程中暂态安全稳定指标；后校验评估指标要求能全面衡量电力系统暂态稳定性，因此本文采用临界切除时间及短路比指标进行评估。电网结构越均衡，发生故障后的潮流转移就越小，电网就更容易恢复到稳定状态。因此电网结构均衡性指标能在一定程度上衡量电力系统暂态稳定。本文对电力系统电气介数计算模型进行改进，提出电气距离权重的电气介数模型。然后引入熵作为电网结构均衡性指标，衡量电网结构指标分布的均衡程度。在此基础上采用小系统算例进行电网建设时序结构均衡性评估，并针对建设时序方案进行后校验。根据小算例测试系统后校验指标可以得到基于结构均衡性的电网建设时序优化过程中暂态稳定性指标能有效衡量时序安全稳定性。本文还针对大电网建设时序进行安全稳定约束条件研究，为大电网建设时序优化提供参考。
[Abstract]:Power system is the key to the development of national economy and society. With the development of society and the progress of economy and technology, the demand for electricity in industry and daily life is increasing, and the demand for power quality is becoming higher and higher. With the development of UHV AC / DC technology, the current power system planning has been challenged. Under this background, this paper uses the time series of large power grid construction to carry out power system planning. The time sequence of large power grid construction is different from that of conventional power system planning, and a time series comprehensive evaluation index system for large power grid construction is put forward. The significance and thinking of the comprehensive evaluation index system are introduced firstly, and the transient security stability index of the comprehensive evaluation index system is studied emphatically. Time series transient security stability assessment of large power network includes optimization process and post-check evaluation. The calculation of transient security stability evaluation in optimization process requires less calculation. Therefore, the structural equalization is used as the transient security stability index in the optimization process. The post-check evaluation index is required to measure the transient stability of power system comprehensively, so the critical excision time and short-circuit ratio index are used to evaluate the stability of power system. The more balanced the power grid structure is, the smaller the power flow transfer will be, and the easier it will be to restore the power grid to a stable state. Therefore, the power system equilibrium index can measure the transient stability of power system to a certain extent. In this paper, the electrical medium calculation model of power system is improved, and the electrical medium model of electrical distance weight is proposed. Then entropy is introduced as the equilibrium index of power network structure to measure the equilibrium degree of the distribution of power grid structure index. On the basis of this, a small system example is used to evaluate the equalization of the time series structure of power network construction, and a post check for the construction timing scheme is carried out. According to the post-check index of the test system based on small calculation example, the transient stability index in the process of power grid construction timing optimization based on structural equilibrium can effectively measure the time series security stability. This paper also studies the security and stability constraints for the construction timing of large power grid, which provides a reference for the optimization of the construction time sequence of large power grid.
【学位授予单位】：华中科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM712

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