电压暂降随机预估与暂降经济性研究

发布时间：2019-05-17 06:12

【摘要】：随着科学和技术的快速发展,敏感设备在很多领域中得到了广泛使用。电压暂降是引起敏感设备不能正常工作的主要原因,由此将导致供电、用电双方巨额的经济损失,造成恶劣的社会影响。电压暂降通常是由线路上发生的短路故障所引起,并具有很强的随机性。评估系统的电压暂降分布情况及其可能带给用户的经济损失,对电网的改造和用户缓解装置的配备具有重要的指导意义。首先为了更加透彻的理解现有的电压暂降随机预估方法,本文总结了国内外大量文献的多种随机预估方法,除了介绍各个方法的原理以外,还比较了各自方法的优缺点,为后续研究方法的改进提供理论基础。在对现有电压暂降随机预估方法有进一步的学习后,本文针对电压暂降评估中传统蒙特卡洛法通常认为线路长度是线路故障率唯一影响因素的缺陷,提出了一种改进的蒙特卡洛方法对系统电压暂降问题进行评估。首先,构建包含线路自身属性及客观因素的线路故障概率评估体系。其次,结合该评估体系,建立完善的短路故障状态变量模型,在PSCAD/EMTDC搭建IEEE-30节点系统仿真模型,运用随机数发生模块和Multiple Run组件对故障信息进行抽样和传送,通过仿真计算得到敏感负荷接入点的电压暂降特征量和评估指标的概率分布。仿真结果表明,改进的蒙特卡洛法相比于蒙特卡洛法在电压暂降评估中更接近电网的真实状况并验证了该方法的有效性。为进一步依据系统侧的电压暂降信息分析用户所承受的暂降情况,本文考虑用户敏感设备的耐受不确定区域的概率分布情况,从而得出用户实际受影响的电压暂降情况。为了便于用户选择合理的治理方法,本文提出了考虑经济性的治理选择方法,并应用NPV法对IEEE-30节点系统中的敏感负荷接入点进行技术经济评估研究。最后为解决现有方法没有考虑敏感设备工业运行状况的不足,提出了基于设备连接状况的过程故障概率评估方法,仿真结果表明所提方法在准确性上进一步提高,具有较好的推广价值。
[Abstract]:With the rapid development of science and technology, sensitive equipment has been widely used in many fields. Voltage sag is the main cause of sensitive equipment can not work properly, which will lead to power supply, huge economic losses on both sides of electricity, resulting in bad social impact. Voltage sag is usually caused by short circuit fault on the line and has strong randomness. It is of great significance to evaluate the voltage sag distribution of the system and its possible economic losses to the users for the transformation of the power grid and the equipment of the user mitigation device. First of all, in order to understand the existing random voltage sag prediction methods more thoroughly, this paper summarizes a variety of random prediction methods in a large number of literatures at home and abroad, in addition to introducing the principles of each method, but also compares the advantages and disadvantages of their respective methods. It provides a theoretical basis for the improvement of the following research methods. After further learning of the existing voltage sag random prediction methods, this paper aims at the defect that the line length is the only factor affecting the line failure rate in the traditional Monte Carlo method in the voltage sag evaluation. An improved Monte Carlo method is proposed to evaluate the voltage sag of the system. First of all, a line fault probability evaluation system including its own attributes and objective factors is constructed. Secondly, combined with the evaluation system, a perfect short-circuit fault state variable model is established, and the IEEE-30 node system simulation model is built in PSCAD/EMTDC. The random number generation module and Multiple Run component are used to sample and transmit the fault information. The voltage sag characteristic quantity and the probability distribution of the evaluation index of the sensitive load access point are obtained by simulation. The simulation results show that the improved Monte Carlo method is closer to the real situation of the power grid than the Monte Carlo method in voltage sag evaluation and verifies the effectiveness of the proposed method. In order to further analyze the sag borne by the user according to the voltage sag information on the system side, the probability distribution of the tolerance uncertainty area of the user sensitive equipment is considered in this paper, and the voltage sag affected by the user is obtained. In order to facilitate users to choose reasonable governance methods, this paper proposes a governance selection method considering economy, and applies NPV method to evaluate the technology and economy of sensitive load access points in IEEE-30 node system. Finally, in order to solve the problem that the existing methods do not take into account the operation status of sensitive equipment industry, a process fault probability assessment method based on equipment connection condition is proposed. The simulation results show that the accuracy of the proposed method is further improved. It has good promotion value.
【学位授予单位】：兰州理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM714.2

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