Some of the improvements attained 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 also have cut the company’s annual carbon footprint by 500 metric tons.
EVER-POWER medium-voltage drive systems allow sugar cane vegetation throughout Central America to become self-sufficient producers of electricity and increase their revenues by as much as $1 million a calendar year by selling surplus capacity to the local grid.
Pumps operated with Variable Speed Electric Motor 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 achieve these benefits, nevertheless, extra care must be taken in selecting the correct system of pump, electric motor, and electronic motor driver for optimum conversation with the process system. Effective pump selection requires knowledge of the complete anticipated selection of heads, flows, and particular gravities. Motor selection requires suitable thermal derating and, sometimes, a complementing of the motor’s electrical feature to the VFD. Despite these extra design considerations, variable rate pumping is becoming well approved and widespread. In a simple manner, a debate is presented on how to identify the benefits that variable swiftness offers and how to select components for trouble free, reliable operation.
The first stage of a Variable Frequency AC Drive, or VFD, is the Converter. The converter is usually made up of six diodes, which are similar to check valves found in plumbing systems. They enable current to circulation in only one direction; the path shown by the arrow in the diode symbol. For example, whenever A-stage voltage (voltage is comparable to pressure in plumbing systems) is usually more positive than B or C phase voltages, after that that diode will open up and invite current to movement. When B-stage becomes more positive than A-phase, then your B-phase diode will open and the A-stage diode will close. The same is true for the 3 diodes on the negative aspect of the bus. Thus, we get six current “pulses” as each diode opens and closes.
We can get rid of the AC ripple on the DC bus with the addition of a capacitor. A capacitor works in a similar style 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 normally significantly less than 3 Volts. Thus, the voltage on the DC bus turns into “around” 650VDC. The real voltage depends on the voltage level of the AC collection feeding the drive, the amount of voltage unbalance on the energy system, the engine load, the impedance of the energy 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 is also 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 electrical energy effectively and increase productivity in energy-intensive industries like cement, metals, mining, coal and oil, power generation, and pulp and paper.