It’s old news that Variable Frequency Drives (VFDs) save energy on centrifugal loads. No one seriously questions that. Variable Frequency Drives (VFD) can also alleviate electric utility company demand charges and penalties, EVEN on constant torque loads such as oil field compressors, positive displacement pumps, and so forth.
As the power grid becomes more stressed, and we see this especially in oil producing areas, starting a large horsepower motor across the line becomes a problem. These are very often medium voltage motors. The electrical utilities simply do not want the grid disturbed with the large inrush currents. One solution can be a reduced voltage softstarter.
There can be two problems associated with using a medium voltage softstarter. The first is obvious; reduced voltage softstarters work by limiting the voltage applied to the motor, which does reduce current, but at the same time, reduces the medium voltage motor’s ability to produce torque. If there are very low starting torque requirements, this can be a viable solution. The second problem, we’ve only begun to see recently.
Some electrical utilities are getting very strict about power factor. Medium Voltage Softstarters are not friendly in this regard, and this can cause a problem.
Another very good solution, is to use a medium voltage Variable Frequency Drive (VFD) to reduce the demand charges and penalties, and in many cases, alleviate the power factor problem. With a properly tuned VFD, the motor can have its full rated torque available throughout the speed range, and never draw more than full load amps.
We’re seeing more and more of this, especially on oil field applications.
Having a problem starting a large horsepower medium voltage drive? Is the electrical utility punishing you with demand charges and penalties? We carry medium and low voltage drives in stock, we sell softstarters, and can do a turn key installation for you. We’re also the best at servicing medium voltage large horsepower variable frequency drives (VFD) and softstarters in the country.
Call us at 800-848-2504800-848-2504 OR use any of the contact methods on the right of this page, including live chat.
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