Transformer Internal Fault Condition Maintenance Based On The Symbol Sequence Analysis

Power transformer is one of hub of key equipment in power system,the safety and reliability of normal operation and equipment directly affects the safety and stability of power system.Power transformer fault occurs,light person will appear local outages,equipment damage accident,the person that weigh will lead to power system blackouts accidents.With further increase the capacity and structure of electric power system,power transformer in the development of large capacity,high voltage grade at the same time,for its safe operation and power supply reliability is also put forward new requirements,the traditional transformer fault detection in real time,accuracy,reliability already cannot satisfy the demand of the modern intelligent power grid.At the present time,transformer's on-line monitoring methods include dissolved gas analysis,partial discharge detector,furfural analysis,infrared thermometry and so on,and all the methods above need complex sensors to support data.So this paper is aim to exploring a kind of relatively simple on-line monitoring method based on Symbolic Dynamic.This article first to classify of transformer,analyzes the structure of the power transformer.On the formation of the fault are summarized,and the various discussi on is made of the causes for its failure.This article selects for interturn short circuit fault as the experimental object,on the basis of predecessors' simulation gives improvement,using MATLAB software platform to simulate source side of transformer internal fault current signal,using the symbol sequence analysis system to build up a mechanism signal differences.First of all,the current waveform signal phase space reconstruction,the current data signal symbol serialization,retain the original signal information as much as possible.System of coding and symbol sequence statistics,to build the word frequency matrix symbol sequences,coupled with CSI common signal index formula to characterize the difference of signal process?In this paper,the introduction of symbol sequence analysis method,the goal of monitoring parameters in transformer internal working current data signals,so there is no need to additional set of sensor devices.Experiment,not only for the simulation o f transformer internal turn-to-turn fault is tested,in addition,this paper also tested the Symbolic Dynamic method on the field test data of transformer internal fault,the result also verified the validity of the Symbolic Dynamic on the detection of transform internal fault.