单相交流参数测量仪设计

Design of single-phase AC parameter measurement instrument

为了测量实验室中DC-AC逆变变频单相交流电参数,设计了基于MSP430F169单片机的单相交流参数测量仪.与采样、过零比较电路配合,利用单片机片内定时器测量频率和相位差;与采样、放大、精密整流和滤波电路配合,利用片内A/D转换器通过瞬时采样法测量电压、电流有效值并计算出视在功率、有功功率和无功功率.经原理样机验证可在LCM12864点阵显示器上显示出各参数测量值.

In order to measure the variable frequency single-phase AC parameters of the DC/AC inverter in the laboratories, the single-phase AC parameter measurement instrument based on MSP430F169 is designed in this paper. The frequency and phase difference are measured by SCM timer combining with the sampling circuit and over-zero comparing circuit. The SCM A/D converter, combining with sampling, amplifying, rectifying and filte- ring circuits,is used to measure the voltage and current and calculate the apparent power, active power and re- active power by instantaneous sampling method. The prototype is proved that it can show the parameters men- tioned above on the LCM12864 dot matrix display.