VFDS LLC

About

VFDS LLC is a leader among variable frequency drive suppliers. Our company concentrates on VFD design and VFD manufacture. VFDS LLC is china VFDS Company located in Shenzhen. Our main focus is creating the highest quality products. The main products single phase to three phase VFD, three Phases to three Phase VFD and so on.

A variable frequency drive controls alternating current torque and motor speed in electro-mechanical drive systems. In layman’s terms, it is an adjustable speed drive that regulates the frequency and voltage to the motor. You can find variable frequency drives, or VFDs, in everything from small appliances to giant compressors.

Variable frequency drive can be used to control the speed of a machine. There can be significant energy reduction if the machine is slowed down when it does not need to operate at full speed. For example, pumps operated so that they run at a speed dependent on the flow requirements will reduce the cavitation losses in the pump. If the pump is required to run at constant full speed, the addition of a VFD will actually waste another 5% of energy.

So, at full load, we may have a VFD at 97% and the motor at say 92% (depending on size and design) and the pump (or machine) may have an efficiency of say 80% or even less, so the wasted energy in the variable frequency drive is small, The wasted energy in the motor is also relatively small. The major losses are in the driven load that is why we target the driven load.

I recently was doing some energy savings projections that involved looking at what would happen if I added a Variable Frequency Drive (VFD) to a pump serving a hot water system. In the course of doing that, I got to wondering if there had been improvements in VFD efficiency that I should take into account since the last time I researched drive efficiency.

Installing variable frequency drives (VFD) are one of the easiest ways to save a significant amount of the energy required to run fans and pumps. Most fan and pump devices are very inefficient when running at part-load conditions, so installing a VFD drastically reduces the energy consumed during those part-load periods. Over the typical life cycle, a VFD greatly reduces the total cost of operation.

A VFD is similar to the motor to which it’s attached, they both convert power to a usable form. In the case of an induction motor, the electrical power supplied to it is converted to mechanical power through the rotation of the motor’s rotor and the torque that it produces through motor slip. A VFD, on the other hand, will convert its incoming power, a fixed voltage and frequency, to a variable voltage and frequency. This same concept is also the basis to vary the speed of the motor without the need of adjustable pulleys or gearing changes.

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