Perm Journal of Petroleum and Mining Engineering (Dec 2016)
Innovative directions of improving electric drive of sucker rod pumping units
Abstract
Liquid lifting from low-rate oil wells is carried out with sucker rod pumping units (SRPU) with plunger`s electric drive from asynchronous electromechanical energy converters. Depending on the rotational speed of rotor shaft asynchronous power converters lift liquid from low-rate oil wells continuously or cyclically. There are some drawbacks of the cyclical operation mode of low-rate oil wells. When using pumping unit`s regular mechanical equipment to switch to a continuous mode liquid lifting from low-rate wells it is required to use asynchronous electromechanical energy converters with a low rotational speed. The article gives information about development of asynchronous energy converters with magnetic field rotation frequency 200 min-1, capacity 3 kW. It offers an innovative way to improve the energy efficiency of low-speed asynchronous energy converters, which is based on the idea of reactive magnetizing current`s internal compensation. The practical implementation of this idea provides a location in the stator slots the electromechanical energy converter of additional compensation winding and its connection to capacitors. The article describes a technique of selecting parameters of the compensation winding and capacitors, providing increase in power factor of electromechanical converter to a value of 1.0. The substantiation of the provisions that additional compensation winding`s location in stator slots of the asynchronous electromechanical power converter does not affect the value of efficiency coefficient. Serial production and widespread introduction in SRPU low-speed asynchronous energy converters, which carry reactive magnetizing current compensation, will significantly increase the volume of produced fluid from oil wells with low flow rate and raise energy efficiency of oil production.
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