Some of the improvements achieved by EVER-POWER drives in energy efficiency, productivity and process control are truly remarkable. For instance:
The savings are worth about $110,000 a year and have slice 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 electricity and increase their revenues by as much as $1 million a calendar year 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 an individual stage, valve elimination, and energy saving. To achieve these benefits, however, extra care should be taken in choosing the correct system of pump, engine, and electronic engine driver for optimum interaction with the process system. Effective pump selection requires understanding of the complete anticipated range of heads, flows, and specific gravities. Motor selection requires appropriate thermal derating and, at times, a complementing of the motor’s electrical feature to the VFD. Despite these extra design considerations, variable rate pumping is now well recognized and widespread. In a simple manner, a discussion is presented on how to identify the huge benefits that variable rate offers and how exactly to select parts for hassle free, reliable operation.
The first stage of a Variable Frequency AC Drive, or VFD, may be the Converter. The converter is usually comprised of six diodes, which act like check valves used in plumbing systems. They allow current to flow in only one direction; the path proven 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 stage voltages, then that diode will open up and allow current to circulation. When B-phase becomes more positive than A-phase, then your B-phase diode will open and the A-phase diode will close. The same holds true for the 3 diodes on the negative part 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 operates in a similar fashion to a reservoir or accumulator in a plumbing program. This capacitor absorbs the ac ripple and provides a even dc voltage. The AC ripple on the DC bus is typically significantly less than 3 Volts. Therefore, the voltage on the DC bus turns into “approximately” 650VDC. The real voltage depends on the voltage level of the AC series feeding the drive, the level of voltage unbalance on the power system, the engine 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 Variable Speed Electric Motor sometimes just referred to as a converter. The converter that converts the dc back to ac can be a converter, but to distinguish it from the diode converter, it is normally referred to as an “inverter”.
Actually, 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.