Abstract
摘要
本论文设计的是一个三相正弦波变频电源，即当输入电压为220V，50Hz时，输出为线电压有效值≥36V，输出频率范围20Hz~100Hz，满足了工业设备和家用电器的需求，特别是应用于电动机调速。本设计从硬件和软件两方面设计，利用PIC系列单片机具有A/D转换模块，CCP模块，LCD驱动模块的优点，将PIC单片机与输入设备(键盘)，输出设备(LCD显示器)连起来构成测量显示电路。将PWM信号控制逆变电路，控制该脉冲的宽度改变输出电压的幅值，改变脉冲的调制周期来改变输出电压的频率。在测量交流电压时，通过真有效值转换电路，可以测得电压的有效值，通过ADC模块，将测量的电压有效值显示在LCD显示器上，利用I/V，F/V转换器，同样可测得电流，频率。PIC系列单片机采用的是RISC精简指令集及其独立分开的数据总线和指令总线的哈佛结构，具有指令集小和简单易学等特点，且允许其指令码的位数多于8位的数据位数，PIC16F877数中级系列产品，其指令有37条，每条指令的字长为14位。
关键词：三相正弦波；变频；正弦波脉冲宽度调制；PWM
Abstract
This thesis is a three-phase sine wave inverter power supply, that is to say, when the input voltage is 220V and 50Hz, the output for the line voltage is over 36V, and the output frequency is range from 20Hz to 100Hz.It is used to meet the needs of industrial equipment and household appliances.In particular, it is applied to motor speed. The design is from both hardware and software,which uses PIC MCU with A / D converter module, CCP modules, LCD driver module. The advantages of the PIC MCU are the input device (keyboard) and output device (LCD display) with up and form measurement display circuit. PWM signal is used to control the inverter circuit. Control the pulse width changes the output voltage amplitude, pulse modulation period changed to change the frequency of the output voltage. In the measurement of AC voltage, through the RMS conversion circuit, the RMS voltage can be measured through the ADC module.The measured voltage is displayed on LCD monitors, the
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Abstract
use of I / V, F / V converter, the same can be measured current, frequency. PIC MCU uses a RISC Reduced Instruction Set and independent separate data bus and instruction bus of the Harvard architecture, instruction set that has the characteristics of small and easy to learn, and to allow their script more than 8 bits of data bits , PIC16F877 number of intermediate products, the instructions are 37, each instruction word length to 14.
Key words: three-phase sine wave;vary frequency; sinusoidal pulse width modulation;PWM
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目录
目录
摘要 ................................................................................................................................ 1 Abstract .......................................................................................................................... 1 第一章 绪论 ............................................................................................................... 1
1.1 课题的目的意义 ............................................................................................. 1 1.2 近年来国内外研究现状 ................................................................................. 1 1.3 基本要求 ......................................................................................................... 2 1.4 设计要求 ......................................................................................................... 2 第二章 方案论证 ....................................................................................................... 3
2.1 变频器的类别 ................................................................................................. 3 2.2 AC-DC模块 ..................................................................................................... 4 2.3 DC-DC模块 ..................................................................................................... 4
2.3.1 MOSFET驱动电路 ............................................................................... 5 2.3.2 PWM波产生电路 .................................................................................. 6 2.4 DC-AC模块 ..................................................................................................... 6 2.5 测量模块 ....................................................................................................... 11
2.5.1 电压测量 ............................................................................................. 11 2.5.2 电流测量 ............................................................................................. 12 2.5.3 频率测量 ............................................................................................. 12 2.5.4 功率测量 ............................................................................................. 14 2.6 控制模块 ....................................................................................................... 14 第三章 硬件部分设计 ............................................................................................. 15
3.1 整流滤波电路 ............................................................................................... 15 3.2 斩波和驱动电路 ........................................................................................... 15 3.3 逆变和驱动电路 ........................................................................................... 16 3.5 真有效值转换电路 ....................................................................................... 21 3.6 单片机及其外围电路 ................................................................................... 23 3.7 电源电路 ....................................................................................................... 27
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三相正弦波变频电源
