Study Of The Intelligent Frequency Converter

At present, the commonly used oil pumping units in the oil field in our country are working commonly in under load or light load condition, caused by imbalanced matching. The power factors of electric motors are low, and they are working inefficiently, thus the energy waste is very serious. The energy saving of oil pumping unit is our goal, and we take the electric motor as our object to control. An intelligent frequency converter controlling system of the oil pumping unit has been designed and realized, using intelligence control theory and AC frequency conversion technology. The thesis has summed up the development of frequency conversion theory and AC timing theory at first. And then according to the current application situation of the intelligence frequency conversion technology and the exiting problems, this system was designed. The intelligence frequency converter has combined the experience of oil field experts, and it can automatically adjust the working system of oil pumping unit, seek the best working curve. The stroke frequency can be changed and the up and down stroke will have a stable transition. When the electromechanical motor of oil pumping unit is in electric power generation state, how to deal with the feed back energy will be a problem. We designed a new energy feed back method to resolve that problem, and reclaim this part of energy. The system uses the 16-bit SCM 80C196MC as the center controller of the frequency converter. Technology of the SVPWM pulse width modulation based on V/F control has been applied and intelligent fuzzy control theory was imported to track and control the rotation rate. The article gives the modulation principle of SVPWM and the design of fuzzy control system in detail. The principle and realization of energy feed back by reactor method that resolve the feedback problem was explained. The soft ware and hard ware design of the system were given. Final test proved that the energy saving effect was perfect and the system has fulfilled the designing requirement basically.