基于Modbus的多功能网络电力仪表的设计

Design of Multi-function Network Power Meter Based on Modbus

文中介绍了一种基于RS-485串行通信接口与Modbus协议的多功能网络电力仪表,给出了该仪表的测量原理、详细的硬件结构和软件求解流程。该仪表以dsPIC33FJ128GP706数字信号控制器为核心,利用MCU内置A/D模块对6路电信号进行实时同步采样,经软件计算实现对电压、电流、频率、功率因数、有功功率、无功功率、电能和谐波等电参量的精确测量,经实验验证精度达到0.5 S级。再配以Modbus现场总线测量和控制模块可组成电力监控系统,实现配电监控系统的遥测、遥信、遥控、遥调的功能。

This paper introduced a kind of multi-function network power meter based on RS-485 and Modbus specification, and presented the measure principle of the system, detailed circuit components and software flow chart. The power meter adopted microchip digital signal controller dsPIC33FJI28GP706 ,and sample simultaneously six channel signal with build-in on-chip A/D. The power meter can measure some power parameters such as voltage, current, frequency, power factor, active power, inactive pow- er, energy and harmonic. The experiment verifies that its precision meets the requirement of 0. 5 S level. Power monitor system may be composed of Modbus field bus measure and control module, and implement the function of remote measure, remote communicate, remote control, remote adjust.