【作者】 曾聪；

【导师】 佘致廷；

【作者基本信息】 湖南大学 ， 控制理论与控制工程， 2006， 硕士

【摘要】 异步电动机因其结构简单、运行可靠、维修方便、价格便宜等优点而广泛应用于各行各业。众所周知电机直接起动有着诸多的弊端;电机轻载运行时,功率损耗增大,效率和功率因数都将大大降低。因此对异步电动机实施有效的控制,保证电机的节能运行,避免电机对电网造成冲击,使之安全经济运行具有十分重要的意义。本文首先进行了异步电动机的功耗分析,通过电路分析和数学推导建立了异步电动机的数学模型及等效电路。对于恒转矩和变转矩两种不同性质的负载,分别讨论了损耗与定子端电压的关系,论证了两种不同负载情况下降压节能的依据。在分析电机功率因数角的变化规律及功率因数角对晶闸管输出电压的影响的基础上,提出了异步电动机在轻载或空载运行时通过检测功率因数并经过一定规则降低定子端电压来达到提高功率因数目的的模糊控制方法,完成了异步电动机节能运行控制系统的软硬件设计,并进行了系统的仿真研究与实验研究。仿真结果及实验结果表明该节能控制器能完成软起动及轻载调压节能的功能。文中还对异步电动机节能控制器的一些技术难点和关键问题提出了有效的解决方法。本文研制了一种通过检测晶闸管的导通与关断,以及检测电网电压同步信号,由87C196KC实现了异步电动机节能控制器的功率因数的检测,具有一定的创新性。采用模糊智能控制方案有效的解决了传统的数学解析方法对电动机及负载适应能力不强的问题,用最简洁的方式,最实用的方法,最廉价的成本,获得最高效的节能功效。更多还原

【Abstract】 Because of such advantage of the asynchronous motor as simple structure, the reliable running, the convenient service and cheap price, it is widely applied in all trades and occupations. It is well known that motor which is direct-on starting has many malpractices. When electrical machinery light-loading running, the power lose increases, the efficiency and power factors both greatly reduce. Therefore it has extremely vital significance to implement effective control on asynchronous motor, guaranting the security of the electrical machinery , avoiding the electrical network impact, enabling it economy running. This paper was precisely had considered above situation, has studied a system based on the 87C196KC which having two kind of control functions-soft start/soft stop and light-loading conserving energy. And has conducted the simulation research. The simulation analysis and the design may comprehensively synthesize considered the influence of each kind of factor on conserving energy the control fixture archery target, which has the vital significance to reduce the development cycle, reduce the development expense and optimize the control plan.This article has first carried on the power loss analysis of the asynchronous motor, has established the three-phase asynchronous motor model and equivalent circuit through the circuit analysis and mathematics inferential reasoning. Relationship of the loss and the stator terminal voltage have been discussed separately, when the load is constant and variable. Through the analysis, the asynchronous motor soft starting frequency and the starting voltage value have been get. The change rule of the three-phase asynchronous motor power factor angle has been analyzed. And the fuzzy control technology has been studied that reduce the stator terminal voltage to achieve higher power factor through testing power factor and using certain rules. The asynchronous motor intelligence operating control system plan design has been completed. Simulation design and simulation experiment of the system has been carried on, and the simulation result indicated this intelligence control system has achieved the anticipated effect. In the article also proposed the certain solution for some technical difficulties and key question about the asynchronous motor intelligence controller. This article has developed a method to lead through the examination crystal thyratron passing with shutting off, as well as the examination electrical network voltage synchronized signal, realizes the the更多还原