混合式有载分接开关在移相变压器中应用的关键问题研究

发布时间：2018-11-27 20:32

【摘要】：论文针对对称双芯移相变压器以及混合式有载分接开关,从移相变压器对有载分接开关的外围技术参数要求和混合式有载分接开关内晶闸管无源触发熄弧原理及工作过程开展了新型混合式有载分接开关在移相变压器中应用的关键问题研究。本文的主要工作和创新成果如下:1、提出了双芯移相变压器等效电路模型,研究了双芯移相变压器在不同运行工况(超前、滞后运行方式、不同负载电流、不同负载电压与负载电流的相角差)下的运行特性。该模型的建立以及不同工况下运行特性的分析对有载分接开关最大级电压的计算、移相变压器的研发设计及制定相应的调控潮流策略等有重要的指导意义。2、提出了双芯移相变压器有载分接开关最大级电压计算方法,并依据实例通过与MATLAB/SIMULINK仿真模型的计算结果对比,验证了所提最大级电压计算方法的可行性和准确性。该方法不依赖于系统潮流计算的结果,避免了复杂的电网潮流分析,没有因为复杂的负荷变化增加计算难度,便于相关工程设计人员的使用,弥补了现有方法繁琐、不可靠的缺点。3、对混合式有载分接开关晶闸管无源触发熄弧原理及切换开关工作过程进行了仿真和试验研究。研究表明:(1)混合式有载分接开关中晶闸管辅助熄弧效果显著、可靠性高,满足移相变压器对开关工作性能的要求;(2)当开断电流在过零点附近时,晶闸管存在不能成功触发的情况,但并不影响开关的开断性能;(3)在晶闸管导通后电流过零自然关断时会形成过冲电压,通过加装氧化锌避雷器的防护措施可以有效抑制过冲电压的形成,形成对晶闸管的可靠保护。
[Abstract]:In this paper, a symmetrical dual-core phase-shifting transformer and a hybrid on-load tap switch are introduced. Based on the peripheral technical parameters of the on-load tap switch of the phase-shift transformer and the principle and working process of the thyristor passive trigger extinguishing arc in the hybrid on-load tap switch, a new type of hybrid on-load tap switch is developed in the phase shift transformer. Research on the key problems of application. The main work and innovative achievements of this paper are as follows: 1. The equivalent circuit model of dual core phase shift transformer is proposed, and the dual core phase shift transformer is studied in different operating conditions (lead, lag operation mode, different load current). Operating characteristics under different load voltage and load current phase angle difference. The establishment of the model and the analysis of the operating characteristics under different operating conditions are of great significance for the calculation of the maximum stage voltage of the on-load tap switch, the R & D design of the phase-shift transformer and the formulation of the corresponding power flow control strategy. A method for calculating the maximum voltage of the loaded tap switch of a dual-core phase-shift transformer is proposed. The feasibility and accuracy of the proposed method are verified by comparing the calculation results with the MATLAB/SIMULINK simulation model. The method does not depend on the result of the system power flow calculation, avoids the complex power flow analysis, does not increase the calculation difficulty because of the complex load change, is convenient for the related engineering designer to use, and makes up for the existing method to be tedious. Third, the principle of passive trigger quenching of thyristor with hybrid on-load tap switch and the working process of switching switch are simulated and tested. The results show that: (1) the thyristor auxiliary arc extinguishing effect is remarkable and the reliability is high in the hybrid on-load tap switch, which meets the requirements of the switching performance of the phase-shifting transformer; (2) when the on-off current is near the zero crossing point, the thyristor can not be triggered successfully, but it does not affect the switching performance; (3) overshoot voltage will be formed when the current is turned off naturally after the thyristor is switched on. The overshoot voltage can be effectively restrained by adding zinc oxide arrester and the reliable protection of thyristor can be formed.
【学位授予单位】：华北电力大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM41

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