The Research Of Heating Power Supply For Oil Tube

With the rapid development of the economy, demand of energy of the countries of theworld becoming more and more, so heavy oil of which the reserves is very rich gets muchattention. So far the heavy oil electrical heating method is generally adopted in oilfieldexploitation, which has advantages of high heating speed、low cost and very environmental andso on. As most of these electric heating devices work by power frequency current, so that there isadverse factor like low heating efficiency、great in power consumption and so on. To aim atstanding problems of power frequency electric heating, and based on power frequency electricheating power device that can be found so far in our laboratory, we researched one new kind ofmedium-frequency electric heating device, by which we can reduce power consumption、raiseheating efficiency and power factor.This topic expounds the current status and trend of induction heating power, and to raise asystem scheme of flow string heating power device, in which two parts are included, that isAC-DC-AC inverter main circuit and control system. The main circuit includes three-phaseuncontrollable rectifying circuit、 intermediate circuit、 inverter circuit. Following loadcharacteristic, inverter circuit adopts voltage type series resonant circuit, so as to make invertercircuit to work at resonance status. As there are problems like narrow frequency tracking range、poor stability and so on when adopting analog phase-locking loop to achieve frequency tracking,so digital phase-locking loop control plot is put forward. We adopt DSP as controller of thesystem, and make use of PWM power modulation way to adjust power output of inverter circuitpart, so as to raise efficiency. Following different practical situation, we can set operationalparameter, so as to make flow string heating power to work at different mode, and so the systemgets very strong adaptability.By MATLAB simulation to digital phase-locked loop frequency tracking, it makes clearthat frequency tracking control plot we adopted is suitable to this system. Testing to each partand the whole device shows that the system can fulfill our predicted researching target, and thesame time correctness of designing and reliability of operation are also gained.