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What is a regenerative drive?
Regeneration is the process of removing kinetic energy from a mechanical system and converting
that energy into electrical power which is injected into the power grid.
In pumping unit applications, the mechanical energy stored in the moving inertia of the pumping
unit is removed by operating the motor as a generator, thereby slowing the speed of the pumping
unit at defined sections of the stroke. Modern regenerative drives are capable of generating large
amounts of electrical energy into the power grid for sustained periods of time.
Typically, 100% of their power rating at 100% duty cycle.
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Are regenerative drives safe? Can they generate power even when the circuit breaker is open?
Power islanding is only possible when prime-mover or some other source of energy is present.
In the case of a pumping unit there is no prime-mover or other source of stored energy.
The only stored energy in the system is that of the counter-weight assembly which is quickly
dissipated soon after removing power from the system.
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Why use a regenerative drive rather than a more standard drive with dynamic braking resistors?
Dynamic braking resistors convert electrical energy into heat, thereby being wasteful.
They are limited in both the amount of energy they can dissipate and length of time they can
dissipate energy, thereby not allowing sufficient braking of the pumping unit.
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Is the extra expense of a regenerative drive really worth it?
In many cases the extra expense of the regenerative drive is worth the higher initial cost.
The potential benefits of regenerative drives: higher pump displacement, increased reliability
of surface equipment, increased reliability of down-hole equipment, low harmonic current and reactive power generation.
In our experience each one of these benefits, or some combination of benefits, has been the
determining factor when considering the costs and benefits of different drive technology.
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What is the “CardBuild®” System?
The
Cardbuild® System is a technology to control any type of variable frequency drive used in a pumping unit application.
It has two main components: Operator Interface and Control.
The Operator Interface portion of the Cardbuild® technology is built for people (operators and technicians) to be reliable,
intuitive and powerful. The Control portion of the Cardbuild®
System at its core is stable, refined and powerful.
Our customers have the summed it up best: “It just works.”
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Does the Cardbuild® system replace a well-manager or pump off controller?
How does the Cardbuild®
system work with other well managers/POC?
The
Cardbuild® system does not include a pump off controller at this time.
The Cardbuild® system works with all major well managers and POCs to effectively control virtually any well with any pumping unit. In general terms, the well manager sends our system a speed reference, usually in the form of an analog signal.
The Cardbuild® system interprets this reference as an overall SPM reference.
The Cardbuild®
system then determines how fast to go at each position of the rod as it moves through stroke, so that the correct SPM is attained, with the proper control at each point.
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Have you licensed the “Cardbuild®” system to any other company?
Not at this time.
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Why do I need the CardBuild®
system? Will a simple regen drive work?
The
Cardbuild® system is the brains for the regenerative drive’s brawn.
You might think of how a car and driver function.
A fast and powerful car is not much use without a skilled driver.
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What makes the CardBuild® system unique? Do you have any competitors?
We are aware of several companies using regenerative drives.
We are unaware, however, of any competitors using anything similar to our Cardbuild®
system.
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Will a regenerative drive save energy?
There are potential energy savings when using a regenerative drive. Regenerative drives are much more energy efficient than drives with dynamic braking resistors. AC Drives in general, including regenerative drives, allow the use of energy efficient low slip motors on pumping unit applications. Using a more efficient motor can improve overall efficiency in pumping unit applications.
