Dynamic Simulation And Performance Analysis Of Frequency Conversion Type Submersible Motor

Nowaday, in the oil exploration and mining work.Submersible motor is a veryimportant equipment which works in thousands of meters deep underground.Thereforsubmersible motor is widely used in various fields of the world.The operational efficiency of the submersible pump can be greatly improvedand the production cost can be reduced when the motor is drived by frequencyconversion velocity modulation. During the same time, a chain of negative issueswill be brought. For instance, high order harmonic will cause the growth of thecopper loss and iron loss.Firstly, the basic principles of a variable voltage variable frequency speedcontrol of induction motors is expounded systemtically. And the impact of thefrequency converter to the electric motor is analyzed from the view of the inverter.Sencondly, basic principle of SVPWM control technology is scribed and theSVPWM inverter model is established with the MATLAB/Simulink software. Onthis basis points, the models of submersible motor’s control system are established.To weaken the influence of over-voltage on the motor, the filtering device isincreased in the long cable situation.Finally, to make the calculation of the harmonic currents easier, the equivalentcircuit of the harmonic is simplified. Based on the equivalent circuit, calculated pulseharmonic electromagnetic torques and the impact of copper loss and iron loss of themotor is analyzed. Then the formation of the terminal over-voltage phenomenon andthe impact of it to the motor are analyzed.Based on that, the countermeasures of thesolution is discussed.