Research On Indicator Diagram Acquisition And Fault Classification Of Pumping Unit Based On Electrical Parameters Method

With the continuous exploitation of oil,the failure rate of pumping unit is higher and higher.It is of great significance for improving economic benefits and ensuring oil supply to accurately grasp the working conditions of pumping units and correctly diagnose the fault types of pumping units.At present,the fault diagnosis of major oil fields is still mainly based on the analysis of indicator diagram.The traditional indicator diagram acquisition method not only needs to shutdown pumping unit affecting the production,but also the equipment is expensive and easy to damage.Engineering technicians also have to face a large number of state identification and classification of indicator diagrams,which has a huge workload and is prone to errors.Therefore,a low-cost and convenient method of indicator diagram acquisition is needed,as well as the corresponding indicator diagram identification method,in order to improve the accuracy of fault diagnosis and reduce the labor level.There is a method of indicator diagram acquisition and fault classification of pumping unit based on stator current and voltage of pumping unit driving motor in this paper.Taking the beam-pumping unit as the research object,this paper analyzes the influence of the factors such as the load of the sucker rod,the balance load,the inertia of the transmission part and the friction on the torque of the motor of the pumping unit,and establishes the relationship model between the electrical parameters and the load of the sucker rod.The electric parameters and basic data of pumping unit(forearm length,rear arm length,beam height,etc.)are used to fit the indicator diagram.A portable electric parameter acquisition device is designed by using USB data acquisition board,and the position of the crank is determined by using photoelectric switch,each complete working cycle of the oil well pump is intercepted,and the indicator diagram is obtained indirectly without stopping.On the basis of the previous research results,the fitting method of indicator diagram is improved to improve the indirect measurement accuracy of indicator diagram.In the face of different fault types,different eigenvalue components are designed with pertinence.The eigenvalues are extracted by MATLAB,and the fault types are distinguished by improved artificial neural network.With the help of acquisition and analysis of the field data,the actual situation of the field pumping unit is compared with the results obtained by the indicator diagram acquisition and fault classification method of the pumping unit based on the electric parameter method designed in this paper.The results show that the method designed in this paper has high accuracy of fault diagnosis and can effectively identify common fault types,which proves the correctness of the theoretical derivation of electric parameter method.This method has the advantages of simple and convenient operation,normal workers and non-professional technicians can operate.It has certain market practical value and application prospect.