Design And Implementation Of Modbus Protocol-based Smart Meter

With the electronic development and progress of science and technology, energy diversification, clean into the direction, in order to optimize the energy structure, promote the transformation of energy strategy goals, is characterized by a new round of clean energy and smart grid energy change is the worldwide promotion. Energy as a clean energy in all aspects of society. Energy meter at the end of the smart grid play an important role as energy metering equipment. The grid gradually expand the scale, centralized monitoring of power supply units on the grid, meter reading accuracy requirements more and more urgent. Since the energy meter more dispersed distribution of its equipment with strong long-range communication function. The needle in this article use the RS485bus low-cost, simplicity, reliability of communication with Modbus RTU bus protocol, proposed a method based on NXP’s ARM Cortex-32LPC1756MCU platform for smart energy meter design, and hardware and software the design and development is described in detail.Firstly, the smart meter at home and abroad research situation, the measurement principle of the electronic energy meter, FFT principle, by comparing the Modbus RTU and ASCII two transmission modes are analyzed. Then introduced from the hardware power meter power supply module, metering module, key display module, communication module, function modules, and each module software design, focusing on the design part of the TOU, the key communication part, Fanbing portion, harmonic analysis part, the frame timing control mechanism of the Modbus RTU protocol and the related functional frame data format, and to the relevant function code examples. Finally, the measurement results are given at different temperatures.Testing in a real environment, the power meter can be well adapted to local temperature conditions. CS5463measurement chip temperature compensation allows the accuracy and reliability of the measurement can be well protected. RS485Bus and Modbus protocol frame combined with a good solution to the monitoring of the power supply unit on the grid terminal. Compared with the traditional power meter, the system is simple, high precision, stable performance, broad market prospect.