更新时间:07-06 (艾薇儿)提供原创文章
摘要:电力系统输电线路中的短路故障大多数是瞬时性故障,因此,自动重合闸技术已经广泛应用于电力系统中,大大提高了供电的可靠性。但传统的自动重合闸技术采用定时重合,不对故障进行判断,即不论瞬时性故障还是永久性故障,自动重合闸都会动作。因此,在故障尚存时可能重合,对系统造成二次冲击,不利于系统的稳定,而且可能会对电力系统和系统中的设备造成很大的危害。为了避免输电线路采用自动重合闸时,重合于永久性故障所造成系统稳定破坏等重大系统灾难,在微机保护的基础上,自适应重合闸的概念应运而生,虽然目前自适应重合闸尚处于理论探索阶段,但它将充分解决双侧有电源110kV线路重合闸成功率低的问题。
本文以佛山电网某双侧有电源110KV线路为例,给出了一种新的自适应单相重合闸方案,该方案与传统的单相、三相、综合重合闸方式相比,能够在合闸前确定故障类型,使重合闸装置能够根据具体的线路不同的故障情况决定动作与否,永久性故障时闭锁,瞬时性故障时启动,再确定合理的合闸时间,就能够使系统避免再次受到短路的冲击,提高系统运行的安全性和稳定性。文章以一回线A相接地故障(IAG)为例就双侧有电源同杆双回线发生单相接地故障时的特征,利用PSCAD/EMTDC建模仿真,提出了识别输电线路单相瞬时性故障的判据,并经动态仿真验证了其正确性。
关键词:自动重合闸;双侧电源;单相自适应重合闸
Abstract:The faults of transmission lines are most temporary ones in power system.So,the auto-reclosure technique has been widely applied in real power systems now.It is an effective method to improve the stability and synchronism power systems.However,the present auto-reclosure technique normally employs a prescribed reclosure time, that is,the breaker is re-closed after a fixed period following a tripping operation without estimating fault nature.Main problem with the conventional reclosure scheme is a risk of a second shock to the system in the case of a permanent fault,when may lead to system oscillation.In order to avoid the power system disaster caused by reclosing on the permanent fault of transmission line,adaptive autoreclosure based on microproeessor-based protection arises at the historic moment,though is still in the stage of theory study.but It adequately solves the problem of low success rate on reclosure that has 110kv power Line with two sides.
In this paper, a network of bilateral Foshan 110KV power lines are an example, a new adaptive single-phase reclosing program, which the traditional single-phase, three-phase, integrated reclosing, compared to the combined pre-determine the type of brake failure, so that reclosing the line can be different according to the specific decision of action or fault conditions, a permanent fault latch, when the start transient fault, and then determine a reasonable closing time, we can make the system to avoid re- the impact by the short circuit, and improve the system security and stability. An one-loop phase to ground fault (IAG) as an example on both sides with power transmission lines with ground fault occurs when the characteristics, using PSCAD/EMTDC modeling and simulation, identification of transmission lines made permanent and transient faults failure criterion, and by the dynamic simulation to verify its correctness.
Keyword: Automatic recloser;Bilateral power; Single-pole adaptive recloser