A few of the improvements achieved by EVER-POWER drives in energy performance, productivity and process 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 enable sugar cane plant life throughout Central America to become self-sufficient producers of electrical energy and enhance their revenues by as much as $1 million a year by selling surplus power to the local grid.
Pumps operated with variable and higher speed electric motors provide numerous benefits such as for example greater selection of flow and head, higher head from a single stage, valve elimination, and energy conservation. To attain these benefits, nevertheless, extra care should be taken in choosing the correct system of pump, motor, and electronic motor driver for optimum interaction with the procedure system. Successful pump selection requires knowledge of the complete anticipated range of heads, flows, and particular gravities. Engine selection requires suitable thermal derating and, sometimes, a complementing of the motor’s electrical characteristic to the VFD. Despite these extra design factors, variable acceleration pumping is now well recognized and widespread. In a straightforward manner, a conversation is presented about how to identify the benefits that variable rate offers and how exactly to select elements for hassle free, reliable operation.
The first stage of a Variable Frequency AC Drive, or VFD, is the Converter. The converter is usually comprised of six diodes, which are similar to check valves used in plumbing systems. They enable current to flow in mere one direction; the path proven by the arrow in the diode symbol. For example, whenever Variable Speed Electric Motor A-phase voltage (voltage is similar to pressure in plumbing systems) is more positive than B or C stage voltages, after that that diode will open up and allow current to flow. When B-phase turns into more positive than A-phase, then the B-phase diode will open and the A-phase diode will close. The same holds true for the 3 diodes on the negative side of the bus. Therefore, 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 functions in a similar style 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. Therefore, the voltage on the DC bus becomes “approximately” 650VDC. The actual voltage depends on the voltage level of the AC series feeding the drive, the level of voltage unbalance on the energy system, the electric motor load, the impedance of the energy 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 tell apart it from the diode converter, it is usually referred to as an “inverter”.
In fact, drives are an integral part of much larger 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.