【作者】 高岩；

【导师】 李永丽；

【作者基本信息】 天津大学 ， 工程硕士（专业学位）， 2020， 硕士

【摘要】 随着世界范围内能源危机的加剧,以太阳能、风能等可再生能源为一次能源的分布式发电技术得到了飞速的发展。配电网中分布式电源渗透率的不断提高给传统的继电保护带来了诸多影响和挑战。探索含分布式电源接入的配电网继电保护原理对于电力系统的安全稳定运行具有重要意义。首先,对逆变型分布式电源的并网结构与控制策略进行了介绍,然后分析其在对称故障与不对称故障下的故障输出特性,提出其在故障输出状态下的等效模型。其次,分析了含分布式电源接入的配电网电流差动保护动作特性。在线路发生区内故障的情况下,利用幅相动作特性分析方法,对幅相特性图中表征线路两侧电流复数比的坐标点受故障过渡电阻和分布式电源并网容量影响下的运动轨迹进行了分析。并分析了制动系数整定值对于电流差动保护灵敏性的影响。然后,针对含分布式电源接入的配电网,提出了一种自适应电流差动保护新原理。该原理依据区内故障与区外故障时线路两侧电流幅值比值的不同特征,自适应地调整制动系数的整定值,以提高保护的动作性能。最后,分别针对同步型分布式电源和逆变型分布式电源接入配电网的情况,对本文所提出的自适应电流差动保护原理进行了仿真验证,并与传统的电流差动保护进行灵敏性的比较,仿真结果表明该原理可有效地提升电流差动保护的灵敏性,具有较强的工程应用价值。更多还原

【Abstract】 With the intensification of the energy crisis worldwide,distributed generation technologies using renewable energy such as solar energy and wind energy as primary energy sources have developed rapidly.The increase of the penetration rate of distributed generation in the distribution network has brought many impacts and challenges to the traditional protection.Exploring the protection of the distribution network with distributed generation access is of great significance for the safety and stable operation of the power system.First,the grid-connected structure and control mode of the inverter-type distributed generation are introduced.Then its output characteristics under symmetric fault and asymmetric fault are analyzed,and its equivalent model is proposed.Secondly,the operation characteristics of current differential protection of distribution network with distributed generation access are analyzed.In the case of a fault in the line,using the amplitude-phase action characteristic analysis method,the motion trajectory of coordinate points representing the complex ratio of the current on both sides of the line in the amplitude-phase characteristic diagram which is affected by the fault resistance and the distributed generation grid-connected capacity is analyzed.And the influence of the braking coefficient on the sensitivity of the current differential protection is analyzed.Then,a new principle of adaptive current differential protection is proposed for the distribution network with distributed generation access.This protection can adaptively adjust the setting value of the braking coefficient based on the different characteristics of the current amplitude ratios on both sides of the line during the internal fault and the external fault.This principle can greatly improve the protection performanceFinally,under the case of synchronous distributed generation and inverter-type distributed generation connected to the distribution network,the adaptive current differential protection proposed in this paper is simulated and verified.The comparison and simulation results show that the adaptive current differential protection can effectively improve the sensitivity of protection and has strong engineering application value.更多还原