Based On Direct Torque Control System Of Screw Pumps Speed Regulation

Induction motors used in traditional oil production system motor structure complex, bigsize and heavy weight, low efficiency due to the presence of excitation device. Encouragepeople to begin focused on PMSM because there is no excitation device, simple structure,design size and weight be small, operational efficiency high. With the breakthrough ofmaterial’s technology and motor manufacturing process, deep research in the motor controlsystem theory and the continuous improvement in practical application, PMSM will slowlyreplace the current induction motor in more and more areas.This topic focuses on the mathematical model of PMSM and control theory conductedin-depth research, combined with the screw pump system working characteristics variableflux as the core of the new three closed-loop control programs is studied, and throughsimulation software conduct related simulation experiments. The following specific research:Introduces the development status of the screw pump system and PMSM use in the oil field,depicts the common structure of PMSM and study on the mathematical model of the idealPMSM in different coordinate systems. Detailed study of the DTC theory and introduction ofthe flux tracking control technology and voltage space vector, different voltage space vectorimpact on stator flux and electromagnetic torque, then establishment of a space voltage vectorswitching logic selection table, given a system block diagram of PMSMDTC. Build asimulation module in the simulation software, assumed different simulation conditions tosimulate actual working conditions in the oil extraction process for system simulation,analyze the results. The direct torque control applied to the speed control system, based ondirect torque control of three closed-loop servo speed control philosophy is studied, and in thesimulation software to build a simulation model corresponds to the system. Conditionscorresponding to the analog set the type of simulation conditions for simulation, andsimulation curves obtained were analyzed, achieve the purposes of three closed-loop speedregulation.