The Software Design Of Phase-shifting Capacitor Insulation On-line Monitoring Terminal

The phase-shifting capacitor which is a capacitance device with reactive power compensation, has many advantages which include the lowest cost of capacity unit, the smallest active power loss, the most simple of operation and maintenance, easy to change capacity and so on. It has a wide range of application in the power system, but in recent years, failure of more and more capacitor for the work environment,the human factors and design problems is a serious threat to the safe operation of the power system, so the insulative state of capacitor must be implemented on-line monitoring.On-line monitoring technology of power equipment is primarily based on measuring dielectric loss, but the existing dielectric loss measurement methods are ill affected to frequency fluctuation and high harmonic influence of the power grid,which can not meet the high accuracy measurement request of the phase-shifting capacitor. The existing insulation monitored devices are generally used cable data communication. On the one hand, it is high-cost of routing and stringing, maintenance difficulties of circuity and serious impact of the terrain. On the other hand ,when the capacitor fails,it can not promptly notify the maintenance staff which causes unnecessary loss.To address the above problems, this article designes a monitor terminal with phase-shifting capacitor insulation on-line monitoring and on-line failure diagnosis, it bases on TI company embedded processor TMS320F2812, embedded real-time operating systemμC/OS-Ⅱand GPRS/SMS wireless communication technology. Major work is as follows.1. This paper adopts the FFT algorithm of Hanning Window weighted to measure dielectric loss , adopts the FFT algorithm of Hanning window weighted interpolation to measure capacitance. At the same time, the text diagnosises comprehensivly insulative state of the phase-shifting capacitor according to dielectric loss and capacitance.2. The thesis decides to use GPRS wireless data communication to upload the real-time measurement parameters of capacitor to the remote server in time, which can analyse rules of capacitor varity and the possible causes of the damage of the capacitor,uses SMS message communication to send warning information to the maintenance staff, when the capacitor fails.At the same time, in order to shorten the software development cycle,the article selects Sony Ericsson GR47 module to design hardware of GPRS, software of GPRS and SMS message, which embeds TCP/IP communication protocol in itself.3. On the basis of in-depth analysis of the characteristics of operating systemμC/OS-Ⅱ,the paper realizes theμC/OS-Ⅱtransplantation and reduction on the TMS320F2812, divides the software multi-task of the entire monitor terminal in accordance with the principles of multi-task division. At the same time,the paper presents software design processes and specific realization methods of each tasks, analyses reliability of the entire monitor terminal from scheduling task,time margin and storage space, completes debug of FFT algorithm.