The Study Of Online Surveillance Equipment For Power Quality Base On DSP

By now, lots of electric and electronic inverters, alone with nonlinear load such as arc furnace, have got widely application. On the one hand, they have greatly enhanced the productivity undoubtedly. On the other hand, they have done great harm to power quality of the applied electric system. At the same time, the development of micro-electronics brings a mass of advanced automatic equipments who are greatly sensitive to the power system's quality. Great losses attributing to low-grade power quality happen at times. So, how to improve power quality and insure these sensitive electronic equipment's reliable operation becomes a stringent and important task, which has attracted great attentions of specialist from home and abroad.In this article, we introduce a set of online power quality monitor who is based on DSP(Digital Signal Processor). The monitor makes full use of DSP chip's strong operation capability. It can monitor power quality online, display real-time measure data and save superscale data, which can provide accurate data to power quality evaluation and improvement. This device can be applied to medium and low voltage distribution output side or the input side of large consumer.Structure of paper: concept of power quality; bringing forward questions of power quality; measurements of power quality; requirements and realization of power quality's online measurement; the appliance and development of DSP processor in power quality measurement. Then comes the detailed description of this monitor: design of data sampling and A/D transition; design of DSP circuit; communication interface design; software design; system commissioning and debugging.The monitor introduces chip TMS320VC5402 of TI company as central processor. It can monitor different parameters of power quality. In order to satisfy the need of real-time requirement, we take following efficient technique: In the field of software, Based on complex sequence FFT operation means with good performance is introduced into Harmonic Analysis; In the hardware field, CPLD is entitled for system logical control; Serial communication derived from UART(Universal Asynchronous Receiver Transmitter) frees the DSP of burdensome control. Multitude interfaces design makes peripheral communication very convenient. Moreover, its friendly human-machine interface and straightforward operation are another marked merit.This monitor has powerful functions, its good performance such as accurate measurement, high measuring speed and good stability has got testified in many field application cases. The application field includes distribution grid and different industrial parks. Furthermore, its extensibility, function and performance is more competent than any other product of same category.