Research And Development Of On Line Fault Diagnosis Edge Agent Device For Generator Excitation System

The excitation system is one of the important components of the generator,which is responsible for providing excitation current to the rotor of the generator and making the generator system reliable,safe and stable production of electricity.So the excitation system occupies a pivotal position in the power system.The excitation power unit is an important part of the excitation system,so it is necessary to diagnose the excitation power unit.At present,most of the excitation power cabinets have no online fault diagnosis system,the device side does not have complex fault diagnosis function,and the recorded wave data cannot be transmitted to the remote monitoring layer in real time for processing when there is the thyristor fails.Therefore,the fault diagnosis is not timely,which has a very serious impact on the stability of the power system.In recent years,edge computing technology and wide-area measurement technology have gradually emerged in the field of power system,and it can synchronize the real-time operation data of the monitored loop with high precision at the data source side,at the same time,it can analyze the data.Then the processed information is stored and is stamped with time stamp.Then the global dynamic information of the power grid is returned to the remote monitoring layer through the network channel.Therefore,based on the network architecture of edge computing,this paper designs the edge agent device for online fault diagnosis of excitation system.Firstly,the model of single bridge excitation power unit is built by SIMULINK,and the typical faults of thyristor in excitation power unit are classified and simulated.The characteristic value of excitation voltage area is extracted and the fault diagnosis algorithm of single bridge is summarized.On the basis of single bridge,the typical faults of double-bridge excitation power unit are simulated,and the eigenvalue of excitation current is extracted,which provides data processing support for the following fuzzy neural network algorithm.Then the esm3352 industrial control board of Yingchuang company is selected as the upper computer of the edge agent device,and the main control chip of the lower computer is TMS320F2810 of TI company.In terms of the hardware circuit of the lower computer,the sampling circuit of excitation voltage and excitation current,GPS signal acquisition circuit,recording data storage circuit and RS485 communication circuit are mainly designed.Then,the software function of edge agent device is designed in this paper.Firstly,the software function of the lower computer is designed,and the program of wide area measurement technology based on GPS,AD sampling based on synchronous time window technology and RS485 communication program are written respectively in CCS3.0 programming environment.Secondly,in the platform of Eclipse open source IDE,the software function of the upper computer is realized by LINUX-C,including the fault diagnosis program of excitation power unit,MODBUS-RTU communication protocol program,recording file storage program,etc.As for the remote monitoring layer,matlab-GUI is used to design the human-computer interaction interface,which can read down the recorded data of the edge agent device,display the operation status of the excitation power unit on the interface,and then store the recorded data into SQL Server 2008R2 database.Finally,the on-line fault test of single bridge excitation power unit is carried out on the experimental platform of Yunqiao power station.The test results show that the function of on-line fault diagnosis edge agent device of excitation system meets the expected design requirements.In addition,for the double bridge excitation power unit fault,based on the excitation current eigenvalue,the fuzzy neural network algorithm is used as a means of fault diagnosis.According to the simulation results,the method is proved to be feasible.