Stimulation Of AC Contactor And Research On Its Intelligent Contorl System

As a frequently used switch apparatus, AC contactor is key to the stability of electrical power system. With the rapid development of science and technology, the requirements of power grid and power system for AC contactors are increasing, therefore, the development and research of new intelligent AC contactor becomes necessary. To carry out the subject, the permanent magnet actuator (PMA) of AC contactor and its corresponding intelligent controller are discussed in this thesis. The principle and structure of PMA are introduced and analyzed, then a complete set of intelligent control system is developed and experimentally studied.Firstly, the thesis introduces the structure and principle of PMA, the dynamic characteristics of which are obtained by building and simulating its model in Ansoft Maxwell, including operation time of closing and opening, velocity and displacement of movable core, current in coil and other parameters, to meet the requirements of AC contactor.Secondly, considering its application occasions and function requirements, an intelligent control system of AC contactor is developed, which equips high performance DSP chip TMS320F2812 as its core processor. The general framework of the intelligent control system is proposed, then modular design concept is used in the circuit design of each function module of the control system, including microprocessor module, signal sampling module, driver circuit module, coil discharge circuit module, power modules, selection phase angle control module and communication module. The software program is also developed, which is divided into a main program and some subroutines. The main program is used to configure the interrupt vectors and call subroutines through various interrupt events, while the subroutines are used to implement the functions of all parts of the intelligent control system.Finally, a confirmatory experiment is carried out based on a 12kV AC contactor prototype. The PCB circuit board is designed based on theoretical analysis, which is tested in the experiment platform built in this thesis, then the selection phase angle control strategy of the AC contactor with PMA is validated. The errors between closing and opening time of the AC contactor and the zero crossing point of the reference voltage signal are observed. The results show that the theoretical analysis is correct and the intelligent control system designed in this thesis is feasible.