A few of the improvements achieved by EVER-POWER drives in energy performance, productivity and procedure control are truly remarkable. For example:
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 enable 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 yr by selling surplus capacity to the local grid.
Pumps operated with adjustable and higher speed electric motors provide numerous benefits such as greater range of flow and mind, higher head from an individual stage, valve elimination, and energy saving. To accomplish these benefits, however, extra care must be taken in choosing the correct system of pump, engine, and electronic motor driver for optimum interaction with the process system. Effective pump selection requires knowledge of the complete anticipated selection 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 considerations, variable quickness pumping is becoming well recognized and widespread. In a straightforward manner, a discussion is presented on how to identify the huge benefits that variable velocity 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 is made up of six diodes, which act like check valves used in plumbing systems. They enable current to stream in only one direction; the path shown by the arrow in the diode symbol. For instance, whenever A-stage voltage (voltage is similar to pressure in plumbing systems) is more positive than B or C phase voltages, after that that diode will open and allow current to movement. When B-phase turns into more positive than A-phase, then your B-phase diode will open up and the A-stage diode will close. The same holds true for the 3 diodes on the negative side of the bus. Therefore, we obtain six current “pulses” as each diode opens and closes.
We can eliminate the AC ripple on the DC bus with the addition of a capacitor. A capacitor functions in a similar fashion to a reservoir or accumulator in a plumbing program. This capacitor absorbs the ac ripple and delivers a clean dc voltage. The AC ripple on the DC bus is normally significantly less than 3 Volts. Therefore, the voltage on the DC bus becomes “approximately” 650VDC. The actual voltage will depend on the voltage level of the AC line feeding the drive, the amount of voltage unbalance on the power 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 to ac is also a converter, but to tell apart it from the diode converter, it is normally known as an “inverter”.
In fact, drives are a Variable Speed Motor 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, coal and oil, power generation, and pulp and paper.