分布式新能源接入配电网的继电保护研究

发布时间：2018-11-16 19:50

【摘要】：针对分布式新能源接入电力配电网带来的配电网保护及馈线自动化问题，分析逆变型分布式电源的并网特性以及当配网故障时逆变器的输出特性，，提出一种适用于含分布式电源配网故障分析的等效模型。以一种已被广泛使用的逆变器为例，根据其已知参数，通过计算，得出逆变器的等效输出阻抗，再结合故障后逆变器内部保护的定值以及动作时限，最终将这些参数计入到已建立的模型中。分析了含分布式电源配电网的短路故障特征量，总结出分布式电源接入不同的位置对保护造成影响的差异。并在此基础上提出了考虑配电网保护的分布式电源选址与定容，即在考虑保护动作以及配电网有功网损的情况下，利用改进的粒子群算法，对含分布式电源配电网进行规划，确定分布式电源的接入位置和容量。在已有研究成果的基础上，进行含分布式电源配电网故障计算。根据本文提出的算法，对分布式电源进行选址定容，继而得到用于故障计算的含分布式电源的配电网。将逆变器的等效阻抗以及控制策略作为建立分布式电源等效模型的重要条件，在故障计算过程中，逆变器的控制策略以及故障输出特性将成为主要的约束条件。通过编程计算，得出不同故障下含分布式电源配电网各节点、支路的电气量。本文在尽量不大幅度改变原有的继电保护及自动重合闸配置的前提下，通过定值及动作时限的调整来实现继电保护装置在分布式电源接入配电网后仍然能够可靠灵敏的动作。分析含分布式电源配电网故障计算的结果，与未接入DG配电网的故障计算结果作对比，总结出含逆变型DG配电网的保护配置方案。最后，归纳提出了逆变型DG“T”接于10kV配网时，配电网保护配置的研究方法及步骤。
[Abstract]:Aiming at the problems of distribution network protection and feeder automation caused by distributed new energy access to power distribution network, this paper analyzes the grid-connected characteristics of inverter distributed generation and the output characteristics of inverter in the event of distribution network failure. An equivalent model for fault analysis of distribution networks with distributed power supply is proposed. Taking a widely used inverter as an example, according to its known parameters, the equivalent output impedance of the inverter is obtained by calculation, and combined with the fixed value of the internal protection of the inverter after the fault and the operating time limit. Finally, these parameters are counted into the established model. In this paper, the characteristics of short-circuit fault in distribution network with distributed power are analyzed, and the difference of influence on protection caused by different location of distributed power supply is summarized. On the basis of this, the location and capacity of distributed power supply considering the protection of distribution network is put forward, that is, under the condition of considering the protection action and the active power network loss of distribution network, the improved particle swarm optimization algorithm is used to plan the distribution network with distributed generation. Determine the access position and capacity of the distributed power source. Based on the existing research results, the fault calculation of distribution network with distributed generation is carried out. According to the algorithm proposed in this paper, the location of distributed power supply is fixed, and then the distribution network with distributed generation for fault calculation is obtained. The equivalent impedance and control strategy of the inverter are taken as the important conditions for establishing the equivalent model of distributed power supply. In the process of fault calculation, the control strategy and the fault output characteristics of the inverter will be the main constraints. Through programming calculation, the electrical quantities of each node and branch of distribution network with distributed power supply under different faults are obtained. On the premise that the original relay protection and automatic reclosing configuration are not changed as much as possible, the relay protection device can still operate reliably and sensitively after the distributed power supply is connected to the distribution network by adjusting the fixed value and the action time limit. The fault calculation results of distribution network with distributed generation are analyzed and compared with those of distribution network not connected to DG. The protection configuration scheme of distribution network with inverter type DG is summarized. Finally, the research methods and steps of distribution network protection configuration when inverter DG "T" is connected to 10kV distribution network are summarized.
【学位授予单位】：华北电力大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM77

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