Study And Design Of CORTEX Platform-based Power Data Acquisition Terminal

As very important elements of information processing and automatic control subjects, data acquisition, processing, control, storage, display and transmission are also the foundation of modern detection techniques. Power data acquisition terminal is the core of a real-time power monitoring system, which can provide a scientific basis for us to analyze power quality, to manage energy, and to research the relationship between power supply and demand. The main goal of our study is to design a CORTEX platform-based power data acquisition terminal. The terminal not only has the ability of measuring electrical parameters such as voltage, current, power, harmonic, but also has perfect communication ability. It is so suitable for real time power monitoring system.The ARM based on CORTEX platform is applied as the control center in the power data acquisition terminal. The terminal is based on the idea of modularization. The hardware circuit design of this terminal contain five modules:power circuit, power data acquisition circuit, MCU circuit using a STM32F103RBT6chip as micro control unit, human-computer interaction circuit and RS-485communication circuit. Power data acquisition terminal uses C language to compile in KEIL simulation compiler environment, and connects with the PC via JTAG emulator to achieve the program development and debugging. By analyzing the characteristics of the main software filtering algorithms, digital filtering algorithm which combine limiter average filtering with Wiener filtering together to eliminate the interference signal is proposed. By analyzing the application of FFT algorithm in harmonic analysis, a comprehensive harmonic analysis method is proposed based on hamming window FFT. In software part the program flow of A/D sampling combined with DMA data transfer is proposed, the A/D parameter configuration function is written, the liquid crystal display module and key acquisition process are analyzed, CRC redundancy check function of MODBUS-RTU communication protocol is proposed to realize remote communication between the power data acquisition and host computer.Finally, the MATLAB software simulation experiment and the Hardware circuit experiment are performed, the results show that CORTEX platform-based power data acquisition terminals which can be used for real-time power monitoring system implement the electrical parameters detection which include voltage, current, power, harmonics and so on.