文档介绍：Abstract
Electronic transformer, fibre-munication technology puter technology constitute the fibre-optic local work, which applies into the power system, is the developing direction of electric substation automation technology. To be the munication standard system aimed to realize the inter-performance among the intellect electron devices of electric substation automation system, according to the monitoring, controlling and relay protection three functions that electric substation automation system must be achieved, IEC61850 divides the system into three layers logically, they are electric substation layer, bay layer and process layer. As the interface of bay layer and process layer, merging unit is used to connect the digital output of electronic transformer and protection, measurement and controlling devices.
This paper has studied pared the digital interface merging unit(MU) correlative standards of IEC60044-7/8, IEC61850-9-1 and IEC61850-9-2, and has pointed out that it has the practical meaning to realize the interface between the optical current transformer and secondary devices based on IEC61850-9-1.
The merging unit collects the data of 12 roads and transfers to secondary equipment according to IEC61850-9-1. This paper divides the merging unit into three modules: synchronizing function module, data collection and deal function module and transmission function module. Since merging unit has the features of multi-dealing-task at the meantime and better real-time character, this paper has designed the scheme which adopts FPGA and controller CS8900A to make up of merging unit.
The synchronizing function module submits the synchronic switching signal to each A/D converter once it has rightly identified the synchronic second pulse- timing signal from the GPS receiver.
After submitting the synchronic signal to each A/D converter, the data collection and deal function module receives the output data from the multi- channels and checks their validity, and then