S270 Oil-pumping (Kowtow) machine special use frequency inverter
S270 Oil-pumping (Kowtow) machine special use frequency inverter
Power Range: 22KW-93KW
Oil pumping machine is specially used to mine underground oil, Oil-pumping(kowtow) machine special use frequency inverter adopt unique and innovative circuit control design, which could be used with all kinds of oil pumping machine in oil field. It could monitor the running data, current, voltage, frequency of the oil pumping machine at any time.
1．Easy to maintain
2．Automatic start after power off
3．Open structure, easy to maintain
4．High energy-saving efficiency, flexible operation
S270 series Frequency inverter model and technical parameters
VF-G7-GH cabinet type special use frequency inverter
S270 Series Oil-pumping (Kowtow) machine special purpose frequency inverter applications
The electricity consumption of Kowtow machine accounts for about 40% of total in oil field。
The average operating efficiency of it is just 25%. Low efficiency, and low power factor makes big energy waste. Therefore, energy-saving potential is enormous for kowtow machine and the oil industry is the key for promotion of "motor system energy conservation". This article describes the use of frequency control technology to realize kowtow machine adapting to changing conditions of oil well, achieving the purpose of efficiency improvement and energy saving.
At present, kowtow machine is the main oil production equipment, the number reaching more than 100,000 units. Motor installed capacity is above 35 million kW totally with more than ten billion degrees of annual power consumption.
2、Several benefits of oil-pumping transformation
1. Greatly improvement on power factor, (from 0.25 ~ 0.5 up to above0.9) reduces the supply current, thereby reducing the load on the power grid and transformer.
2. Dynamic adjustment of extraction speed implements energy saving on one hand and improves the crude output at the same time.
3. For motors, gearboxes, pumping units, it implements real "soft start" to avoid excessive mechanical shock and extend equipment life
3.kowtow machine load analysis.
1、 Beam pumping unit is most widely used in China, which consists of three parts:
(1) Ground segment: the motor, speed reducer and four-link
（2) Underground part: Defueling pump (suction valve, pump cylinder, plunger and drain valve), it hung in the lower end of the bushing.
(3) Sucker rod: connecting the middle part of the ground pumping unit and underground defueling pump
2、Kowtow machine load is changing based on periodic, starting with large load and high torque, but around 20% load rate on normal operation, only 30% at high load. There are two peaks for motor load curve which respectively is the upper and lower stroke "dead center" of kowtow machine
without balance, upper and lower stroke load is extremely uneven。At upper stroke, it needs to lift rod string and the liquid column. Motors need to give large energy. At the lower stroke, rod string works on the motor making it in power generation status. Typically plus weights on the crank kowtow machine, eliminating the unbalanced load of vertical stroke. There is less time spent and energy generated in balance condition. Due to the pumping load changing all the time, the counterweight is impossible to change at the same time with the pumping load, so most kowtow machine counterweight is in serious imbalance, resulting in excessive inrush current, which can be up to 5 times than operating current, even up to 3 times than rated current. Adjusting the counterweight can reduce the impact current to 1.5 times than normal operating current.
Load characteristics: a constant speed, because the counterweight is variable torque, there is twice power generation state for variable power load in a cycle with big starting torque and inertia. In domestic, the common problem in kowtow machine: long-time running, low efficiency, high energy-consumption. Stroke and speed adjustment is not convenient with free pumping phenomenon.
4、The difficulties of traditional kowtow machine inverter transformation
Lots of attempts on kowtow machine for energy-saving, but not successful, the main reasons are below:
(1)Kowtow machine have two power generation states in a work cycle, especially in imbalance counterweight, resulting high "pumping voltage" ., the problem cannot be completely solved by increasing electrolytic capacitors on inverter DC side and reducing the braking resistor value. Meanwhile, with the change of reservoir, "pumping voltage" also changes.
(2)Kowtow machine starts with larger starting torque, if the parameters are improper setting, easily lead to over-current or starting failure.
(3)There is little consideration on oil level and oil concentration changes according to previous frequency energy 5、 solutions
We have offered below solutions for kowtow machine transformation
(1) The use of SVF-G7-CY frequency control technology implements the motor speed and kowtow machine load matching. Because it is big oil in early exploration, setting the drive running to 65.00Hz, the motor speed increased by 30%, oil production rate will increase by 20% than before and also efficiency to1.2 times. In late wells, oil decreases, the general frequency operation to 35.00 ~ 40.00Hz with reducing speed and stroke, the motor speed decreased by 30%. In that way, it improves the power factor with 25% energy saving.
(2) Dynamic adjustment for kowtow machine stroke frequency: with the oil extraction from shallower to the deeper, oil decreases, pump is insufficient, pump efficiency drops when the supply capacity of the well is less than the pump displacement, causing pump evacuation and fluid hammer. Reducing the frequency, decreasing motor speed， increasing fullness, not only can save the energy but also can increase oil production.
(3) dynamical adjust the speed of kowtow machine for upper and lower stroke, appropriate to reducing the lower stroke speed and improving the fullness of the pump, appropriate to increasing upper stroke speed can reduce the leakage coefficient in enhancing, so that kowtow machine can work in best state, effectivly increasing crude oil production as per unit time.
(4) Big start torque, low load operation, large inrush current, to solve the problem at bottom, it needs to increase the pole pair number of the motor or gearbox ratio and increase the output torque. 80.00 ~ 90.00Hz for drive operation, it helps to reduce the energy in power generation state and "pumping voltage."
(5) Increasing inverter filter capacitor on DC side; reducing the braking resistor value and improving the power capability of the braking system is feasible for energy regeneration processing problems. Or using regenerative braking directly, reducing energy loss; frequency increases in power generation.
(6) Pumping air defense with dynamic adjustment kowtow machine stroke frequency and the upper and lower stroke speeds, setting the standard value of motor power output, real-time detection the output power, controlling motor speed, greater than the standard value, acceleration. Conversely, deceleration, closed-loop control is implemented.
Since the oil type and conditions differ in thousands of ways, oil leakage and seepage are changing all the time underground. Load change of kowtow machine is irregular, so using frequency control technology, kowtow machine movement adapted to oil well conditions, to achieve system efficiency, energy saving and production improvement.
Corresponding parameter set not found, please add it in property template of background
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