串级调速毕业设计论文.doc

文档介绍：串级调速毕业设计论文
摘要
串级调速系统是在转子回路中串入附加电动势,以改变转差率来实现调速。串入附加电动势而增加的转差功率,回馈给电网或者回馈到电动机轴上使系统有较高的运行效率。它能实现无级平滑调速,低速时机械特性也比较硬。特别是晶闸管低同步串级调速系统,技术难度小,性能比较完善。
本设计介绍了一种双闭环控制的串级调速系统,对系统的工作原理、组成及动态结构作了较为详细的论述,分析了交流串级调速系统工作时的主要特征,并据此对其与正常接线或转子回路串电阻调速时的效率做了一般性的定性分析和比较。针对传统串级调速系统总功率因素低这一主要缺点. 分析了一种转子侧加短路开关的串级调速系。转子侧加短路开关的串级调速系统因能充分利用电机自然工作状态功率因数高的特性,在带恒转矩负载时功率因数有一定程度的提高分析了一种转子侧加短路开关的串级调速系。
本设计报告首先根据设计要求确定调速方案和主电路的结构型式,主电路和闭环系统确定下来后,对电路各元件参数的计算和器件选型,包括整流变压器、整流元件、平波电抗器、保护电路以及电流和转速调节器参数计算,从而达到设计要求。
关键词:串级调速;闭环控制;功率因数;整流电路;
逆变
Abstract
The cascade velocity modulation system is the string enters the additional EMF in the rotor return route, changes the sliding to realize the velocity string enters slips the power which the additional EMF increases, the back coupling for the work or the back coupling to the electrically operated engine shaft on enable the system to have the high operating efficiency. It can realize the stepless smooth velocity modulation, when the low speed the physical characteristics quite is also hard. The thyristor low synchronization cascade velocity modulation system, the technical difficulty is specially small, the performance quite is perfect.
This design introduced one kind of double closed-loop control cascade velocity modulation system, to the system principle of work, position and the dynamic structure has made a more detailed elaboration, has analyzed time the exchange cascade velocity modulation system work main characteristic, according to the above and has made the general qualitative analysis to it with the normal wiring or time the rotor return route string resistance velocity modulation efficiency pares. Lowers this main ing in view of the traditional cascade velocity modulation system total output factor, analyzed one kind of rotor side to add the shorting contact switch the cascade governing system. Because the rotor side adds the shorting contact switch the cascade velocity modulation system to be able fully to use the electrical