The Power Quality Monitoring Terminal Based On DSP

With the gradual establishment of the electricity market in China, power quality with high performance has attracted people's attention. The users require high-quality power to ensure the normal operation of the equipments, instruments and systems. However, As the advancement of the modern technology, on the one hand, power electronic equipments have an ever-increasing utilization, and has seriously affected the power quality. On the other hand, the increasing use of the precision instruments needs higher accurate and reliable distribution system, which can provides the adequate power. Moreover, as the rapid development of the electric industry and the expansion of the power network, the power dispatching automation system needs higher level. Based on this, the Power Quality Monitor Terminal was developed to monitor and analyze the power quality in the power system. It can play a monitor role on the power network to analyze the loss of the power, so it has its significance to improve the efficiency of the use of the electricity.This paper discusses in detail in the design and implementation methods of the monitor terminal in the power detective system. The terminal is the block between the remote PC and the power network, to samples, analyses and transports data. Base on the capability of the digital signal processing of DSP, the power parameters can be real-time monitored. The terminal is based on embedded TMS320LF2407A as a core for computing. Through the hardware filtering and synchronous sampling, the terminal can collect three-phase voltage and current on the real-time, then computes the parameters based on FFT and other arithmetics. The terminal also has the function of transporting data to the remote PC in GPRS for statistic, analysis and storage. This can provide the electricity department the long-term and effective data.The practices have shown that the part of the hardware filtering and synchronous sampling can have a good effect in measurement speed and accuracy; the part of the software arithmetic has been verified through MATLAB simulation in its accuracy and efficienc. The terminal can also be used for the most of the low-frequency harmonic analysis system through appropriate changes. So it has a broad practical value.