真空断路器永磁机构智能控制系统设计.doc

摘要 作为一种新型的操动机构，永磁操动机构具有零部件数量少、可靠性高、免维护等传统断路器操动机构所无法比拟的优点，受到了世界各国的普遍关注。 本次设计主要是对中压断路器永磁操动机构的原理、静态吸力、动态特性及控制系统进行研究分析，并对永磁机构断路器的智能化进行了探讨。其中静态磁场的计算采用了目前应用较为广泛的有限元方法，对永磁单独作用的机构静态吸力特性和激磁电流与永磁共同作用的吸力特性进行了分析计算。在动态计算中本文根据永磁和激磁电流共同作用这一特点，建立了相应的数学模型，给出了动态微分方程组的求解方法，并对动态过程进行了分析。通过动态特性的计算，获得了电容放电激磁下的永磁操动机构线圈电流、产生的磁力、动铁心的速度、位移及电容电压随时间变化的曲线，并分析了各项电参数对动态特性的影响，为产品的设计提供了理论依据。 本次设计探讨了基于单片机的高压真空断路器双稳态永磁机构智能控制系统设计，这种控制系统集保护、控制、测量、开关量监测等功能于一体。可实现对电压、电流、有功功率、无功功率的实时监测，具有过电流速断保护、过电压和欠电压保护、闭锁、自诊断以及报警等功能。在设计的最后部分，探讨了中压真空断路器的智能控制和同步关合技术。 关键词：永磁机构；智能控制；真空断路器 Abstract As a kind of new Actuator of Circuit Breaker,Permanent Magnetic Actuator(PMA)has the advantage of less parts,higher reliability and maintenance-free and so on,so it has been paid more and more attention by people all over the world. In the paper,the mostly work is the study on Middle-voltage Circuit Breaker PMA,its principle,the static characteristic,the dynamic characteristic and the control system.In the calculation of static magnetic field,the Finite Element Method(FEM)is used.The force characteristic of PMA with exciting current and without exciting current are calculated and analyzed.Because the dynamic character of PMA is affected by permanent magnet and exciting current,in this paper,new mathematic model and equation are established and the calculation result is analyzed.The data of exciting current,magnetic force,Moving-core velocity,Moving-core displacement and capacitance voltage at any time during opening and closeing operation and every factors effect on dynamic character are obtained. In the paper，the intelligent control unit based on single-chip microprocessor for intelligent breaker integreates many functions such as protection,control,and measurement.The signals of currents,voltages，active power and reactive power are monitored in real time.The control unit can not only control opening/closing operation of circuit breaker,but also has the functions of over-current/under-voltage trip，closing/opening interlock for