三相正弦波变频电源的设计
摘 要
本设计分为：三相SPWM信号的生成、逆变回路及其驱动和输出的测量显示。选择电机控制专用DSP TMS320LF2407生成SPWM信号。逆变电路主回路采用智能功率模块(IPM)。输出测量采用电压电流传感器来实现电隔离。为加快速度，采用独立于DSP的PIC单片机实现输出的测量。
关键词： 变频；SPWM；DSP；PIC单片机
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Abstract
The design is about tri-phase sinusoidal frequency conversion power. Three parts are included: generating tri-phase SPWM signal, inverter circuit and its drive circuit, output measuring and display. DSP TMS320F2407 is used as the controller in the system. IPM is used in the Inverter main circuit. Voltage and current sensor is used in the measuring of output, it can insulate the control circuit conveniently.PIC microcontroller is used independently to measure and display output.
Key words: frequency conversion , SPWM , DSP , PIC microcontroller
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一． 方案论证与比较
1．1变频电源逆变方案
根据题目的要求将交流电经整流后，经过逆变从而产生三相正弦波电源。而实现三相正弦波变频电源的关键在于逆变过程。对于小功率逆变电路一般都采用PWM技术，为了实现正弦波变频电源，本设计采用了SPWM技术。实现SPWM有以下几种方案。
方案一： 采用规则采样法。规则采样法一般采用三角波作为载波。其原理就是用三角波对正弦波进行采样得到阶梯波，再以阶梯波与三角波的交点时刻控制开关器件的通断，从而实现SPWM法。
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