This text derive and offer asynchronous power factor relation of motor expressed and show at first, and regard power factor of the asynchronous motor as the target of controlling , make the motor run under higher power factor , Reduce the loss which does not have function quantity, thus achieve the energy-conserving goal. Emulation result indicates , when the motor is in unloaded and light year, can make certain energy- conserving result .
Asynchronous motor is used in industrial and agricultural production and consumption of a maximum of electrical equipment. In electric drive system, often with the highest load plus margin to design parameters and selection. In actual operation, the load will change with the actual requirements and changes, it will have electrical power load drag on the situation. Through the load current motor, motor load voltage and power factor analysis, can be found: When the motor for light-load or no load when the motor power factor lower when the motor for the full load of high power factor. Higher energy saving power factor is an important task. Frequency Control is a typical high-speed DC motor way, it applies to asynchronous motor, but also to synchronous motor. AC motors can be used not only VVVF stepless speed regulation, but under different load, through the appropriate voltage and frequency adjustment of the relationship between the motor will always run at high efficiency, and to ensure good dynamic performance.
Key word: One-chip computer; Power factor; Asynchronous motor; Energy-conservation
目录
0 引言………………………………………………………………………………1
1概述 ……………………………………………………………………………2
1.1 调速的意义与发展状况…………………………………………………………2
1.1.1交流调速技术发展的概况与趋势……………………………………………2
1.1.2变频调速的意义和发展概况………………………………………………2
1.2变频调速的一些基本概念………………………………………………………3
1.2.1交流电动机调速方式…………………………………………………………3
1.2.2变频调速 ……………………………………………………………………4
1.2.3变频装置 ……………………………………………………………………10
1.2.4正弦波脉宽调制（SPWM）变压变频器…………………………………… 13
1.3本论文的目的和任务………………………………………………………… 19
2异步电动机的功率因数 …………………………………………………………20
3带有功率因数自动控制的异步电动机变频调速系统的设计………………… 25
3.1主电路的设 ……………………………………………………………………25
3.2单片机及其扩展……………………………………………………………… 26
3.2.1单片机简介…………………………………………………………………26
3.2.2 8098及其扩展…………………………………………………………… 27
3.3 SPWM波的形成与驱动…………………………………………………………38
3.3.1 SPWM波的形成………………………………………………………………38
3.4反馈信号的测取和功率因数的输入…………………………………………43
3.4.1 电压和电流反馈信号的测取………………………………………………43
3.4.2 转速检测……………………………………………………………………44
3.5 系统原理与程序流程……………………………………………………… 44
4 技术经济分析 ……………………………………………………………………47
5结论…………………………………………………………………………… 48
致谢……………………………………………………………………………… 49
参考文献 …………………………………………………………………………50
附录 A 译文…………………………………………………………………… 51
附录 B 外文文献……………………………………………………………… 58
