CTM Magnetics specializes in power quality products for high power applications. We design and manufacture products both for the line side and load side of power conversion equipment. Liquid cooling has been a focus at CTM for more than a decade. In 2006 we introduced the world’s first liquid cooled reactor. Since then the company continued to improve that technology and now has redefined thermal management in power electronics. Continuous advances over the last decade led to far lower costs and higher thermal efficiencies so that, today, liquid cooled reactors are less expensive than their air cooled counterparts.
As we’ve pointed out elsewhere, liquid cooling is far more effective than air cooling of power quality products. This is especially true in high power applications. However, liquid cooling delivers several additional and important benefits as well. Here’s a short recap of those benefits.
Highest Power Density Available
Removing heat via liquid cooling allows design engineers to reduce the overall dimensions of the product. For instance, a reactor consists of three coiled windings. These naturally suffer from losses due to wire resistance, and hysteresis and eddy currents in the magnetic material. With liquid cooling, a smaller enclosure can be used due to liquid’s superior heat dissipation. In addition, because liquid cooling keeps the device’s surface temperature low, typical clearance requirements between components are significantly reduced or eliminated. A greater number of devices can fit into a given volume of space. These add up to the highest possible power density per cubic inch whether one or a cluster of power management products are deployed.
Liquid cooled equipment is more reliable on two counts. First, the superior heat dissipation of liquid versus air cooling leads to lower operating temperatures. Electronic components last longer at lower temperatures. Second, enclosing the device in a sealed cabinet protects the device from harsh environments that would otherwise reduce its useful life.
In addition, it is easy to monitor coolant temperature and to set an alert if temperature climbs too high, further adding to reliability.
Liquid cooling systems remove heat from the inductor directly through the cooling agent without raising ambient cabinet temperature. Up to 97% of the heat is removed via the liquid cooling agent. For instance, in a typical NEMA 3R cabinet, installation of an air cooled reactor increases cabinet air temperature by more than 20°C . The equivalent liquid cooled reactor raises cabinet air temperature by only 1.4°C. The low temperature rise provided by liquid cooled reactors increases the reliability of all electronics within the cabinet.
“Stealth Worthy” Silent Operation
Magnetostriction is the change in shape ferrous metals undergo when exposed to magnetic fields. It causes energy losses and is the cause of the audible hum typical of transformers and other inductive devices. CTM’s unique design geometry minimizes inductor noise caused by magnetostriction. Using a fully potted and sealed epoxy material further mutes any noise, giving CTM products a “stealth worthy” rating.
The fully potted design used in liquid cooled products offers complete protection in some of the harshest environments. Only electrical terminals and cooling connections remain exposed, making integration with customers’ systems fast and easy, and protecting the magnetic components from environmental damage.
Efficiency and reliability go hand in hand with liquid cooled devices. Some of the same design features that improve reliability also increase efficiency.
For example, thermal efficiencies provided by liquid cooling allow the product’s component size of parts to be smaller. Smaller magnetic cores yield lower magnetic losses. Less efficient thermal cooling technologies would not be able to utilize these smaller parts because there is not enough surface area to adequately cool the part.
Additionally, CTM Magnetics uses low core loss materials, which adds further efficiency, especially in high frequency applications. This is a benefit of all CTM products regardless of the cooling system.
Finally, since wire resistance is a temperature-dependent value, lower operating temperatures lead to lower resistance, yielding lower power losses.
Liquid cooling has found its way into dozens of applications and markets where the benefits summarized here are required. A few of these include…
- Industrial chillers
- Renewable energy
- Battery Energy Storage
- Marine and Offshore
The wind energy industry uses liquid cooled filter systems where superior thermal management and maximized energy efficiency are required.
The military uses liquid cooled reactors and filters because they are the smallest and most efficient, and because they are environmentally sealed against even the harshest environments.
Marine and offshore oil platforms use liquid cooling for the efficiency it provides, and also because space is at a premium on watercraft and off-shore drilling platforms. The small physical dimensions of liquid cooled products saves space.
Transportation, solar energy, air conditioning and other industries that need the most efficient power quality products all enjoy the benefits of liquid cooling.
To learn more or to discuss your specific needs, contact us. Our engineers look forward to speaking with you.