A Study On Algorithm And Equipment For Power Quality Monitoring Based On DSP

The problem of power quality gets prominent as lots of electric and electronic devices have got widely application. Many advanced automatic equipments are sensitive to power quality. Great losses attributing to low-grade power quality happen at times. How to improve power quality and insure these sensitive electronic equipment's reliable operation has attracted great attentions of specialist from home and abroad.In this paper, the concept of power quality, the meaning of power quality indexes are introduced, the measurement algorithms of power quality indexes are analyzed and studied, and a set of online power quality monitor based on TMS320C32 - a floating-point DSP is developed, which realizes the online monitoring of power quality by introducing the powerful computation ability of DSP chip and provides the accurate data to power quality evaluation and improvement. This device can be applied to medium and low voltage distribution input side of large consumer.This device introduces the high-speed AD converter chip AD676 to realize the analog-to-digital conversion, and Z85C30 to expand serial ports, CPLD to realize the system logic control so as to realize the acquisition of analog data, the calculation and storage of power quality parameters and the serial communication.In order to satisfy the real-time requirements, the FFT operation means with good performance based on complex sequence is introduced into the harmonic analysis; In order to reduce the error because of asynchronous sampling, this paper studies the algorithm with which the amplitudes of harmonics can be estimated from the two neighboring spectral lines and uses polynomial approximation method of MATLAB to obtain the polynomial approximation formulas for frequency and amplitude correction based on the Blankman-harris window. The error cause in the electrical quantity measurement using asynchronous sequence sampling is discussed. Based on the technique of asynchronous sequential sampling, an accurate measurement approach is presented for the measurement of distortional electrical quantity. Simulating result shows that presented approach can provide much better computational precision.The system hardware structure with floating-point DSP TMS320C32 as the core is designed. The assemble language and C language of TMS320C32 are deeply studied,...