A few of the improvements achieved by EVER-POWER drives in energy effectiveness, productivity and process control are truly remarkable. For instance:
The savings are worth about $110,000 a year and also have slice the company’s annual carbon footprint by 500 metric tons.
EVER-POWER medium-voltage drive systems allow sugar cane vegetation throughout Central America to be self-sufficient producers of electricity and increase their revenues by as much as $1 million a season by selling surplus power to the local grid.
Pumps operated with variable and higher speed electric motors provide numerous benefits such as greater range of flow and mind, higher head from a single stage, valve elimination, and energy Variable Speed Electric Motor saving. To accomplish these benefits, nevertheless, extra care must be taken in selecting the appropriate system of pump, electric motor, and electronic motor driver for optimum interaction with the process system. Successful pump selection requires understanding of the complete anticipated selection of heads, flows, and particular gravities. Electric motor 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 debate is presented on how to identify the huge benefits that variable rate offers and how to select elements for hassle free, reliable operation.
The first stage of a Variable Frequency AC Drive, or VFD, may be the Converter. The converter is certainly comprised of six diodes, which are similar to check valves found in plumbing systems. They enable current to movement in only one direction; the path demonstrated by the arrow in the diode symbol. For example, whenever A-stage voltage (voltage is comparable to pressure in plumbing systems) is certainly more positive than B or C stage voltages, after that that diode will open and invite current to stream. When B-stage becomes more positive than A-phase, then the B-phase diode will open up and the A-stage 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 works in a similar fashion to a reservoir or accumulator in a plumbing system. This capacitor absorbs the ac ripple and provides a simple 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 will depend 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 energy program, 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 distinguish it from the diode converter, it is usually referred to as an “inverter”.
In fact, drives are a fundamental element of much bigger EVER-POWER power and automation offerings that help customers use electrical energy effectively and increase productivity in energy-intensive industries like cement, metals, mining, oil and gas, power generation, and pulp and paper.