含分布式发电的配电网保护研究及微机保护装置设计

发布时间：2018-05-28 08:57

本文选题：分布式电源 + 配电网保护　；参考：《浙江大学》2017年硕士论文

【摘要】：随着能源形势和环境问题的严峻,以太阳能、风能等可再生能源为代表的分布式发电技术(DG,Distributed Generation)得到了越来越多的重视和发展。大量分布式电源的接入,改变了配电网原有的单侧电源辐射性结构,使传统的配电网保护策略无法快速、正确地动作。另一方面,随着智能配电网的建设,微机保护得到了大力发展,微机保护的应用以及通讯网络的建设,使基于多点信息的广域保护策略成为可能。基于此背景,本文着重研究了分布式电源接入对配电网保护的影响和广域保护策略,同时,对微机保护装置进行了具体分析和设计。本文首先针对逆变型分布式电源,详细建立了恒功率控制策略下的并网逆变器模型并进行了故障分析,以此为基础得出了用于保护分析的DG简化模型。然后,重点研究了 DG接入配电网对传统三段式电流保护的影响,并以典型配电网模型为例,仿真分析了 DG不同容量和接入位置时的情况。与此同时,分析了DG对重合闸的影响,指出重合闸可能出现误动或非同期合闸等现象。基于微机测控保护装置,本文研究了基于多点信息的配电网广域保护方案,包括集中式和分布式两种具体结构,通过采集多点信息,综合分析和判断,以实现故障定位和切除。DG一般通过逆变器并网,可能会产生大量高次谐波,同时对配电网保护的快速性提出了更高要求。为此,本文详细研究了适用于微机保护的滑窗离散傅里叶算法(Sliding Discrete Fourier Transform,SDFT),分析了各种形式 SDFT 的基本原理。针对SDFT的稳定性问题,研究了其不稳定原因,并提出了交错并行SDFT的稳定性方法,能够保证各种形式SDFT的稳定运行。最后,本文详细介绍了微机保护装置的系统架构和工作原理,并给出了具体软硬件设计方法。
[Abstract]:With the severe energy situation and environmental problems, distributed generation technology, such as solar energy, wind energy and other renewable energy, has been paid more and more attention and development. The access of a large number of distributed power sources has changed the original radiation structure of the single side power supply of distribution network, which makes the traditional protection strategy of distribution network unable to move quickly and correctly. On the other hand, with the construction of intelligent distribution network, microcomputer protection has been greatly developed. The application of microcomputer protection and the construction of communication network make the wide area protection strategy based on multi-point information possible. Based on this background, this paper focuses on the influence of distributed power access on distribution network protection and the wide area protection strategy. At the same time, the microcomputer protection device is analyzed and designed in detail. In this paper, a grid-connected inverter model based on constant power control strategy is established and fault analysis is carried out. Based on this model, a simplified DG model for protection analysis is obtained. Then, the influence of DG access to distribution network on the traditional three-segment current protection is studied, and the typical distribution network model is taken as an example to simulate and analyze the DG with different capacity and access location. At the same time, the influence of DG on reclosing is analyzed. Based on the microcomputer measurement and control protection device, this paper studies the wide area protection scheme of distribution network based on multi-point information, including centralized and distributed two concrete structures, through the collection of multi-point information, comprehensive analysis and judgment. In order to achieve fault location and removal. DG is usually connected to the grid by inverter, which may produce a large number of high-order harmonics. At the same time, higher requirements are put forward for the fast protection of distribution network. In this paper, the sliding window discrete Fourier algorithm for microcomputer protection is studied in detail, and the basic principles of various forms of SDFT are analyzed. Aiming at the stability of SDFT, the causes of instability are studied, and the stability method of staggered parallel SDFT is proposed, which can guarantee the stable operation of SDFT in various forms. Finally, the system structure and working principle of microcomputer protection device are introduced in detail, and the design method of hardware and software is given.
【学位授予单位】：浙江大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM774

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