A few of the improvements Variable Speed Electric Motor achieved by EVER-POWER drives in energy efficiency, productivity and procedure control are truly remarkable. For instance:
The savings are worth about $110,000 a year and also 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 be self-sufficient producers of electricity and enhance their revenues by as much as $1 million a year by selling surplus capacity to the local grid.
Pumps operated with variable and higher speed electrical motors provide numerous benefits such as greater range of flow and head, higher head from a single stage, valve elimination, and energy conservation. To attain these benefits, however, extra care must be taken in selecting the correct system of pump, electric 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. Electric motor selection requires suitable thermal derating and, sometimes, a complementing of the motor’s electrical feature to the VFD. Despite these extra design factors, variable quickness pumping is becoming well recognized and widespread. In a straightforward manner, a discussion is presented about how to identify the huge benefits that variable swiftness offers and how to select elements for trouble free, reliable operation.
The first stage of a Variable Frequency AC Drive, or VFD, is the Converter. The converter can be comprised of six diodes, which act like check valves found in plumbing systems. They allow current to circulation in mere one direction; the path proven by the arrow in the diode symbol. For instance, whenever A-phase voltage (voltage is similar to pressure in plumbing systems) can be more positive than B or C phase voltages, after that that diode will open and invite current to stream. 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 part 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 functions in a similar fashion to a reservoir or accumulator in a plumbing system. This capacitor absorbs the ac ripple and delivers a clean dc voltage. The AC ripple on the DC bus is normally less than 3 Volts. Hence, the voltage on the DC bus becomes “around” 650VDC. The actual voltage will depend on the voltage degree of the AC series feeding the drive, the amount of voltage unbalance on the power system, the motor load, the impedance of the power system, and any reactors or harmonic filters on the drive.
The diode bridge converter that converts AC-to-DC, is sometimes just known 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 known as an “inverter”.
Actually, drives are a fundamental element of much larger EVER-POWER power and automation offerings that help customers use electrical energy effectively and increase productivity in energy-intensive industries like cement, metals, mining, coal and oil, power generation, and pulp and paper.