Some of the improvements achieved by EVER-POWER Variable Speed Motor drives in energy efficiency, productivity and procedure control are truly remarkable. For example:
The savings are worth about $110,000 a year and have cut the company’s annual carbon footprint by 500 metric tons.
EVER-POWER medium-voltage drive systems allow sugar cane plants throughout Central America to become self-sufficient producers of electrical energy and increase their revenues by as much as $1 million a calendar year by selling surplus power to the local grid.
Pumps operated with variable and higher speed electric motors provide numerous benefits such as greater selection of flow and mind, higher head from an individual stage, valve elimination, and energy saving. To attain these benefits, nevertheless, extra care should be taken in selecting the appropriate system of pump, electric motor, and electronic engine driver for optimum conversation with the procedure system. Successful pump selection requires understanding of the complete anticipated range of heads, flows, and particular gravities. Motor selection requires appropriate thermal derating and, at times, a complementing of the motor’s electrical characteristic to the VFD. Despite these extra design factors, variable acceleration pumping is becoming well accepted and widespread. In a straightforward manner, a discussion is presented on how to identify the benefits that variable acceleration offers and how exactly to select parts for hassle free, reliable operation.
The first stage of a Variable Frequency AC Drive, or VFD, may be the Converter. The converter is usually comprised of six diodes, which are similar to check valves used in plumbing systems. They allow current to circulation in only one direction; the path proven by the arrow in the diode symbol. For example, whenever A-phase voltage (voltage is similar to pressure in plumbing systems) is definitely more positive than B or C phase voltages, after that that diode will open up and invite current to flow. When B-phase turns into more positive than A-phase, then your B-phase diode will open up and the A-phase diode will close. The same is true for the 3 diodes on the negative side of the bus. Thus, we get six current “pulses” as each diode opens and closes.
We can eliminate the AC ripple on the DC bus by adding a capacitor. A capacitor operates in a similar fashion to a reservoir or accumulator in a plumbing system. This capacitor absorbs the ac ripple and provides a easy dc voltage. The AC ripple on the DC bus is typically less than 3 Volts. Thus, the voltage on the DC bus becomes “approximately” 650VDC. The real voltage depends on the voltage level of the AC line feeding the drive, the level of voltage unbalance on the power system, the motor load, the impedance of the power program, and any reactors or harmonic filters on the drive.
The diode bridge converter that converts AC-to-DC, is sometimes just referred to as a converter. The converter that converts the dc back again to ac can be a converter, but to distinguish it from the diode converter, it is generally known as an “inverter”.

Actually, drives are an integral part of much bigger EVER-POWER power and automation offerings that help customers use electricity effectively and increase productivity in energy-intensive industries like cement, metals, mining, oil and gas, power generation, and pulp and paper.