Research On Model Predictive Control Of Permanent Magnet Synchronous Motor In Oil Drilling Rig System

The importance of energy to the existence and development of society is beyond doubt,and energy has the most important strategic position in any country and region.In the current basic energy of human consumption,the petroleum energy occupies the primary position.The complete set of drilling equipment for oil exploration and scale development is the oil rig.It is a large combined unit,consisting of several systems and corresponding equipment.Among them,the power system equipment provides power for the operation of the oil drilling rig.Because the Permanent Magnet Synchronous Motor(PMSM)has simple structure,small volume and light weight,it has obvious advantages in driving load and reducing equipment,compared with other motors in terms of structural flexibility.In addition,PMSM has the advantages of high power density,high efficiency,high reliability and so on.Therefore,PMSM is used as the power equipment of the oil drilling rig system,and its control strategy is studied in this dissertation.The operation of the working unit of the oil rig system is analyzed.The structure and classification of PMSM,the mathematical models in the three coordinate systems,and the coordinate transformation between the three is introduced.The coordinate transformation between the three coordinate systems is analyzed in detail,and the mathematical model in the dq coordinate system is established.According to the oil drilling process with nonlinearity,uncertainty and time-varying,the dynamic matrix predictive control algorithm which belongs to model predictive control algorithm is applied to PMSM speed loop control.Through model prediction,rolling optimization and feedback correction steps,the speed control is achieved,and the simulation model in Matlab/Simulink environment is established.Compared with the traditional speed loop PI control,the superiority in the dynamic response and robustness of the system of PMSM based on dynamic matrix predictive control is proved.In the analysis of the operation of the oil rig unit system,considering the complexity of the working environment and working conditions of the drilling system,the external unknown and unpredictable disturbances and model mismatch serious situation make the whole speed control system performance decreases obviously,and its parameters also changes,thereby affecting the normal work of the drilling system.Therefore,aiming at the problems of load disturbance and motor parameter changes under complex conditions,a disturbance feedforward compensation device based on extended state observer is designed,which combines dynamic matrix predictive control with extended state observer.Through the analysis and comparison of simulation,the dynamic matrix predictive control which disturbance feedforward compensation device has better dynamic response performance,and the stability of the speed is better under the load interference.It is proved that the control strategy can match the control requirements of the driving motor for the oil drilling rig system in complex conditions.