The Study On Reciprocating Pumping Unit Control System

Linear motor-driven reciprocating pumping unit is a direct linear reciprocating motion form power transformation. It improves the efficiency of pumping unit, realizes the smooth pumping parameters, adjusts the suspension center movement variation with pumping situation, and gives a good foundation for intelligent pumping unit. A good control strategy is necessary for this kind of pumping unit. The control system studied in this dissertation is right about cylindrical permanent magnet synchronous Linear motor-driven reciprocating pumping unit.Firstly, the principle of a linear motor and the concrete conditions to use linear motor for pumping unit are discussed in this dissertation. The structure of submersible permanent magnet synchronous linear motor-driven reciprocating pumping unit is also introduced in this dissertation. Then the mathematical model of linear motor is derived out and its control strategy is analyzed in detail.Secondly, according to the mathematical model of linear motor, its simulation model is established in Matlab/Simulink. Then the entire control system model is built in accordance with the selected control strategy based on the SVPWM technical field orientated vector control for permanent magnet linear synchronous motor. It is proved that the strategy is feasible by the results of the simulation.Thirdly, the control system is designed based on the work above. Its main function is rectifying the three-phase sinusoidal AC to DC out and controlling intelligent power module IPM to inverse it to a three-phase AC of adjustable frequency. The control system contains three parts, including the main circuit, the control and measurement.The main circuit is controlled by three-phase rectifier bridge; TMS320LF2407A is the core part of the control board. Its main function is the signal acquisition, operation and giving an output named PWM motor drive signal to drive IPM to achieve power conversion; the measurement contains the detection of current, speed and position. The current transformer is used to acquire the current signals; the hall proximity switch and the hall sensor is used to acquire position and detect speed signals. After converting, all acquired signals will be deposited into the DSP to realize the motion commutation and velocity control.