The Research On The Measuring And Controling Instrument Of The Distribution System's Parameters Based On PIC MCU

In order to ensure the safe operation of distribution systems and know the statusof distribution system operation , there is a need that parameters should be measuredand monitored in time, and then be sent to the control center. It stimulates a wideapplication of the measuring and controling instrument for the low voltage distributionnetwork's parameters nowadays. When cost or management is taken intoconsideration, it may not be appropriate to operate both the reactive powercompensation system and the measuring and controling instrument for low voltagedistribution systems at the same time. In this paper, the author introduces a design bywhich the two instruments can be integrated into one, in accordance, the cost of theinstruments will be reduced greatly, and the management will be more flexible. Themeasuring and controling instrument utilizes voltage and current inductors totransform the AC signal at the three-phase and four-wire system, uses the specialelectric energy calculation chip to measure the transformed signal, and then sends themeasured parameters to the main controller by SPI interface. This instrument utilizesPIC16F877 as the main controller to control and monitor the whole system. At thesame time, the instrument owns the function of the reactive power compensation andis equipped with the RS485 communication, so it can send measured parameter to thecontrol center. The precision of this instrument has already reached national industrystandard. It is a new-type instrument which can measure and monitor distributionsystems, proofread power factor, and has the role of reactive power compensation.The measuring and controling system enjoys many advantages,such as simplestructure,high precision and stong anti-disturbing,etc. It has enormous marketpotential.