at different points in their distribution systems and the effects of various mitigation methods. With most of these tools, you select the sizes of the inverters that you plan to use and enter the loads and duty cycles that you expect. The results of the subsequent analysis can help you to select the most cost-effective design for the application.

Although harmonic-mitigation technologies such as AC line reactors and DC chokes have been around for a number of years, the trend has been to deliver them in smaller packages. An example is Acoposmulti from B&R Automation. The technology relies on an active power supply module that can reduce fifth and seventh harmonics that a passive six-pulse rectifier can generate. The active power supply and accompanying filter technology result in very low harmonics and in a total power factor that is essentially 1.The active power supply can return kinetic braking energy to the AC mains, instead of wasting it by dissipating it as heat through resistors.

Although power regeneration reduces the amount of heat generated from dissipating braking energy across resistors, there are other losses associated with inverters that affect the size of the switching cabinet. To deal with this extra heat, B&R Automation can offer cold-plate cooling. The technique uses water to transport the heat generated by the inverters and power supply to the outside of the cabinet, where it can be dissipated into either the air or an existing liquid-cooling system.

“Liquid cooling is nice because it is an efficient way to remove the heat from the control room,” offers Morton. “Depending on the amount of heat and the size of the room, this could have a significant impact on the air-conditioning requirements.” It’s just another example of how the various technologies for keeping your electrical power free of surges, sags, and hidden harmonics can clean up your bottom line.

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