基于无触点控制技术的混合式无弧交流接触器的研究 毕业设计1.doc

摘 要 交流接触器是一种应用特别广泛的低压电器，特别是在低压配电领域及自动化控制领域更是具有不可替代的作用，所以提高交流接触器性能稳定性对电力自动化领域来说具有很重要的意义。随着材料科学的发展，交流接触器的机械寿命得到很大提升，但是远低于机械寿命的电寿命却成为了制约交流接触器发展的瓶颈所在。对于AC-4使用类别下，合闸阶段触头二次弹跳产生的断续电弧和分闸阶段产生的电弧是影响交流接触器电寿命的主要因素。综上所述，解决交流接触器合闸阶段触头弹跳问题和分闸阶段产生的电弧问题是提高交流接触器电寿命的关键所在。 针对交流接触器合闸阶段触头弹跳问题和分闸阶段产生的电弧问题，本文主要从两大方面对交流接触器进行改进：第一电磁系统改进，针对交流接触器采用交流励磁所带来的问题，提出了多段脉冲稳压直流激磁和直流小电压保持的激磁方案。并且设计了智能激磁操作执行机构，从而保证了激磁过程的稳定性；第二针对触头系统进行智能改造。国内外对于交流接触器分闸过程进行了系统的研究，就国内而言，过零分断控制技术是研究热点。随着电力电子技术的发展，电力电子开关器件越来越成为低压电器控制的焦点。本文采用的无触点分断理念，具体做法是在交流接触器每相触头两端并联一个双向可控硅，并且配套设计相应的触发电路。使得双向可控硅在交流接触器分闸过程中实现分流，这样便可以使交流接触器实现无弧分闸操作,大大提高了交流接触器的电寿命。 除了针对交流接触器合闸和分闸阶段进行智能改造外，本文还对交流接触器增加了可靠实用的智能保护功能，主要给予交流接触器过压、欠压、过载、漏电保护等功能，保证了交流接触器智能分合闸环境的稳定性以及使其更趋于智能化。 关键词：交流接触器；智能激磁；无触点控制技术；智能保护 Abstract AC contactor played an irreplaceable role in the field of low-voltage distribution and automation control. So consistency?of?performance?of the AC contactor has great economic significance. But further development has so far been constrained by its electrical life which below the mechanical life’s level. The direct effect on electrical life is electric arc that has produced in switching process. Especially under the use of categories of AC-4, the arc generating by switching process become the key restriction of the electrical life of the AC contactor. In view of the above problems, this paper put forward a research plan about intelligent Low voltage Ac contactor without arc. As to the problems in the closing and breaking process, we make the intelligent improvement to solve them. The improvement includes two aspects. one aspect is the improvement of electromagnetic system. this paper designs the corresponding experimental circuit used to determine the specific field parameters which mainly about the DC excitation voltage and DC small voltage. And the design of the intelligent excitation operation of the actuator thereby ensures the stability of the excitation process. The other aspect is intelligent transformation according to the contact