兰州理工大学毕业设计说明书
摘 要
随着发电机单机容量和电网规模的增大，发电机组及电力系统对励磁控制在快速性、可靠性、多功能性等方面提出了愈来愈高的要求，相应地，励磁控制在理论和实践上也在不断更新、发展和完善。传统的模拟式励磁调节器已不能满足需要。近年来，基于微机控制系统的发电机励磁调节系统已逐渐取代模拟式励磁调节器而成为同步发电机励磁调节器的主流。
发电机在正常工作情况下，负载总是不断的变化着。而不同容量的负载，以及负载的不同功率因数，对同步发电机励磁磁场的作用是不同的，对同步发电机的内部阻抗压降的作用也是不一样的。要维持同步发电机端电压为一定水平，就必须根据负载的大小及负载的性质随时调节同步发电机的励磁。显然。这一调节过程只有通过电压的自动调节装置才能实现。本系统主要完成上述功能。
本课题中自动励磁系统该采用以80C196MC单片机为核心的触发电路代替目前国内市场上流行的集成化KC系列触发电路。该电路具有功耗小、功能强、输入阻抗高、抗干扰能力强，移相范围宽（0—177°），外接元件少等优点，而且调试简单、使用可靠。
本文主体分为四个部分。
第一部分是单片微机励磁系统结构，论述基本系统构成及各个部分的作用与相互间的协同工作。
第二部分是基于80C196MC单片机的微机励磁调节器硬件设计。 第三部分是控制算法研究，讨论PID控制在励磁装置中的应用。
关键词:励磁调节器，80C196MC单片机，数字电路，PID控制,
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兰州理工大学毕业设计说明书
ABSTRACT
With the single generator capacity and power grid scale of the increase, generators and power systems group of excitation control in the fast, reliability, versatility, and other aspects of the increasingly high demand, accordingly, excitation control in theory And in practice are also constantly updated, to develop and improve. Traditional analog excitation regulator has been unable to meet the need. In recent years, computer control system based on the excitation-conditioning system has been gradually replaced analog excitation regulator and a synchronous generator excitation regulator of the mainstream.
Generators under normal working conditions, the load always changing. The different capacity load, and load the different power factor, the synchronous generator excitation magnetic field is different from the role of the internal synchronous generator impedance voltage drop is not the role of the same. To maintain synchronous generator terminal voltage to a certain level, it must be based on the size of load and load regulation at any time the nature of the synchronous generator excitation. Obviously， This adjustment process is only through the automatic adjustment voltage devices can be achieved. This system is mainly to complete these functions. The subject of the excitation system automatically 80C196MC used to trigger circuit as the core of the domestic market instead of the current popular on the integrated circuit triggered KC series. The power circuit with small, strong function, high input impedance, anti-interference capability and phase-shifting wide range (0-177 °), the advantages of fewer external components, and debugging simple to use and reliable. This paper is divided into four main parts.
The first part is exciting single-chip computer system architecture, on a basic system and various parts of the role and inter-work together. The second part is based on the 80C196MC excitation regulator computer hardware design.
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兰州理工大学毕业设计说明书
The third part is to control the algorithm to discuss the PID control in the application of excitation device.
Key words: excitation regulator, 80C196MC microcontroller, digital circuits, PID control
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兰州理工大学毕业设计说明书
目录
摘 要 ...................................................... I ABSTRACT ................................................ II 第一章绪论 ................................................. 6
1.1概述 .................................................. 6 1.2励磁控制系统的任务及作用 ............................. 8 1.3研究的目的和意义 ..................................... 9 1.4国内外研究动态和趋势 ................................ 10 1.5设计的内容和方法 .................................... 11 1.6对励磁调节器的要求 .................................. 12
第二章励磁调节器的硬件组成及功能 ....................... 14
2.1励磁调节器的功能和硬件总体框图 ...................... 14
2.1.1励磁调节器的基本框图 ........................... 14 2.1.2励磁调节器的功能 ............................... 15 2.2各测量电路的设计和计算 .............................. 15
2.2.1交流电压测量技术 ............................... 15 2.2.2励磁电流的测量 ................................. 19 2.2.3用霍尔电压传感器测励磁电压 ..................... 19 2.2.4发电机频率f测量技术 ........................... 22 2.2.5脉冲触发同步电路 ............................... 24 2.2.6功率驱动电路 ................................... 30 2.3 80C196MC单片机简介 ................................. 31
第三章励磁调节器控制算法分析 ............................ 37
3.1励磁控制系统的传递函数 .............................. 37
3.1.1各环节的传递函数 ............................... 37 3.1.2励磁控制系统传递函数框图 ....................... 38 3.2介绍数字PID控制的基本算法 .......................... 40 3.3对控制算法的评价 .................................... 41 3.4参数的整定方法 ...................................... 42
第四章数字式励磁调节器的软件实现 ....................... 43
4.1调节器的软件结构 .................................... 43 4.2中断处理............................................. 44 4.3对功率因数采样的数据处理 ............................ 46
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兰州理工大学毕业设计说明书
4.4对功率因数采样数据处理 .............................. 50 4.5数据采样............................................. 50
4.5.1用电量变送器测量极端电压、机端电流 ............. 51 4.5.2励磁电压、励磁电流测量模块 ..................... 51 4.6对可控硅控制角的计算 ................................ 52
4.6.1对PID进行计算 ................................. 52 4.6.2无功调差的概念 ................................. 53 4.6.3测量有功功率P和无功功率Q ..................... 56 4.6.4发电机频率F的测量程序设计 ..................... 57 4.6.5励磁限制 ....................................... 58 4.7系统程序片段 ........................................ 60
总结 ....................................................... 65
参考文献................................................... 67 英文翻译原文 .............................................. 69 英文译文................................................... 81 致谢 ....................................................... 905