Real-Time Monitoring Machine Of Distribution Transfoemer Based On GPRS And SPI Interface

Distribution network SCADA((Supervisory Control and Data Acquisition) is very important in power system automation. Low pressure distribution network is consist of lots of transformers which are here and there dispersedly. Obviously, concentrative management is the preponderant method that setting a supervisory center to administrate all the real-time monitoring machine, which is installed on every transformer. Supervisory center manages the data of all the real-time monitoring machine.To communicate between the supervisory center and real-time monitoring machine, it is very important to select appropriate communication network. Analyzing the actuality of SCADA and the feasibility of GPRS(General Packet Radio Service), the GPRS network is selected as the communication channel.The SPI(Serial Peripheral Interface) is employed to exchange data and in-system programming. It will transmit data effectively and quickly, using SPI simplifies design process, reduces design cost, what's more, it is convenient for system extend in future.Firstly, data collecting module collects three-phase power data, real-time module gets current time, relay module gains relay status. Secondly, the data collected is judged weather.over limit, if it is over limit, machine sends all data to supervisory center. Thirdly, machine sends all data at intervals. Last, if supervisory center wants to control some relay, it will command machine to execute turning on or turning off relay based on supervisory center command.To complete the process, firstly designing the whole hardware, including data collecting, real-time clock, relay-control, communication, MCU(Micro Control Unit) module. In addition In-System Programmer(ISP) is designed. It is introduced how to download program with ISP. Secondly, analyzing software demand, the main program, interrupt program, ATT7022 reset, data collecting, relay-control, abnormal-data alarming, data sending program is respectively designed. Lastly, ATT7022 is adjusted by software.