ABB's new drive generation capture braking energy from electric motors and return it in to the network as an almost harmonics-free current.
In industry electric motors are often used in applications with frequent brake applications. A braking chopper and external electrical resistors dissipate braking energy as heat. It is lost or even has to be cooled using additional energy. Whereas regenerative drives can feed this braking energy back into the mains improving energy efficiency significantly.
ABB has for long been the leading supplier of such solutions: ABB's series of regenerative drives, the industrial drives ACS880, cover an output range of 4 to 3,200 kilowatt (kW) – the broadest range in the market. They can cut energy consumption considerably, reduce space requirement by up to 85 percent thanks to their compact design and cut investment costs by up to 30 percent. Moreover reduced heat dissipation significantly reduces the need for electrical room air conditioning.
Energy saving thanks to regenerative braking
Recovered energy is "clean" and has a high quality. It can be used by other loads increasing plant efficiency significantly. The new generation of ABB industrial drives is able to control cosine phi of the fundamental to unity under all load conditions so that the reactive power and energy consumption are optimized.
The braking energy dissipated as heat in traditional methods such as resistor and mechanical braking usually requires additional cooling. Reduced heat dissipation due to regenerative braking considerably reduces the need for air conditioning of the electrical room.
The following example illustrates how much energy can be saved by means of such solutions: For a crane used in waste handling with a 55 kW hoisting motor, a 9 kW long travel motor and a 4.5 kW trolley motor and a regenerative drive annual savings total approx. 15.6 megawatt hours (MWh) – or 2,300 euros. This reduction by 32 percent corresponds to the annual energy consumption of four German households.
Eliminating troublesome harmonics
Non-linear electrical loads, also including variable speed drives, cause harmonics leading to unwanted voltage and current distortions in the networks. These harmonics result in unreliable operation and can heat other loads such as motors, transformers and other electrical equipment excessively. This requires additional cooling, causes energy loss and in the worst case pre-mature failure.
Although additional electrical filters may attenuate such harmonics, it is however preferable not to allow them to be created at all. This is exactly what ABB's new variable speed drives do, they prevent harmonics before they appear. ACS880 can control cosine phi of the fundamental to unity under all load conditions optimizing reactive power and fully meets harmonics standards such as IEEE519, IEC61000-3-12 and G5/4.
Fewerdowntimes through higher reliability
The new ACS880 regenerative drives feature high immunity to system disturbances and can stabilize and even improve motor voltage in case of instable supply. This ensures reliable operation even if supply voltage drops below the normal value.
Compact package optimizes costs and saves space
Since there is no need for external brake components, ABB's regenerative drives are significantly more compact than conventional solutions. Reduced engineering and material costs and a smaller footprint in the electrical room deliver considerable savings potential regarding the cabinet building costs.
The wall-mounted ACS880-11, the ACS880-14 modules and the cabinet-built ACS880-17 are equipped with all the required components installed in a compact enclosure ready for connection. This facilitates and accelerates cabinet installation additionally because there is no need for the subsequent wiring of various components.
Digitalization and connectivity for process optimization
In addition to all these advantages the ACS880 drive can also be used as a multiple sensor reading important data such as motor speed, motor torque, motor currents, various temperatures and many other parameters. This data is then available for diagnosis, remote monitoring and process optimization via ABB Ability – bundling all products, services and solutions into ABB's digital offer including cloud connection.
