Simulation Of Variable Frequency Drive For Submersible Progressing Cavity Pump And Cycloconvertor Design

With the development of our country's oil industry, the ElectricSubmersible Progressing Cavity Pump (ESPCP) has a large scale using inthe petroleum exploitation. One of the technology bottlenecks of ESPCP'sdriving system is that the rotationa l speed of submersible motor is not anice match for the Progressive Cavity Pump, but the frequency conversiontechnology can solve this problem.In the dissertation the author firstly analyzes the characteristics of theESPCP and its disad vantages in use, and then introduces the state of the ACspeed regulation. With MATLAB for tool, the thesis compares the harmonicwave of wave-shape outputted by various control methods, andcycloconvertor is chosen as the fina l project. In the part of frequencyconversion speed control, a control system is designed which uses a motordedicatedIC chip 80C196KC ma nufactured by Intel Corporation . Thesystem hardware circuit design and the software design are finished. Thesystem ma inly includes the ma in circuit, control loop circuit, power-inputtransformer and so on, which can provide low-frequency voltage. The ma incircuit of device adopts three-phase half-bridge zero type structure, whichmakes up of 18 SCRs. The control unit consists of phase sequence test unit,voltage in-phase test unit, pulse generator and zero-current checkout unit.The software of frequency conversion control for ESPCP is designed in Cprogram. It realizes phase sequence test, 10Hz square-wave voltage outputand ma n-machine operation interface. Fina lly, the experiments of loadma nifest that the performa nce of system is good and the system meets therequirement.