Foreword: Current, oily facility is taken in oil field in, apply with pumping unit of kowtow of walking beam type most general, the amount is maximum also. But, traditional kowtow engine is existing generally to start concussion big, report of moving bad news is much, car of big Ma La, efficiency is low coarse and a lot of problem, case of together with wildcat is complex, phenomenon of stiff oil, paraffin precipitation, sanded card is more, stop staff, burn the phenomenon such as electric machinery to often happen, do not have reliable protective function to electromotor, equipment maintenance amount is large, for this, be badly in need of undertaking transforming to existing pumping unit equipment.
Frequency control appliance has low speed soft start, rotate speed is OK smoothly big range adjusts, all ready to electromotor protection function, like short circuit, overload, press too, owe pressure reach stall to wait, can protect electric machinery and mechanical equipment effectively, have move smooth, reliable, increase a lot of good point such as effect, it is the good program that the equipment that pump oil transforms. We are close to distant river oil field, victory oil field 40 wells undertook frequency conversion is transformed, its application effect is very apparent.
One, the fundamental of transducer
Talk by electric mechanism knowable, formula of its rotate speed isN=60f/p × (1 - S)
Among them P, of electromotor extremely logarithm
S, turn poor rate
F - the frequency of power supply sourceN - the rotate speed of electromotor
By on type can see, electric machinery rotate speed and frequency become direct ratio approximately, change frequency adjusts smoothly namely electric machinery rotate speed, and to transducer, the adjusting range of its frequency is very wide, can adjust arbitrarily between 0 ～ 400Hz, because rotate speed of this electric machinery can be namely inside wider range,adjust.
Of course, after rotate speed rises, return the impact that should consider to its bearing reachs winding, prevent electric machinery to wear away overly reach overheat, general and highest frequency is set in 50Hz or 65Hz.
Power parts of an apparatus is Xi Menzi's IGBT, the core of controller is 87C196MC sheet piece machine.
2, the difficulty of pumping unit transducer
As the equipment that pump oil, its move to promote up and down for again and again, a stroke promotes, its motivation comes from the steel qualitative slide block with two quite large weight that drive at electromotor, lift when slide block when rising, be similar to the action of lever, send pumping unit lever into the well, when slide block drops, sucker rod puts forward to carry oil to wellhead, because electric machinery rotate speed is certain, drop in slide block in the process, bear is reduced, electric machinery pulls the energy that uses generation not to have local discharge, certainly will enters second birth to generate electricity condition, cause advocate loop generatrix voltage is elevatory, frequent high pressure pounds meeting attaint transducer advocate parts of an apparatus, include to electroanalysis capacitance and power module, because this increases return of apply the brake, let second birth voltage be released in time, work in order to assure equipment below safe voltage.