Energy resistors are utilized in power era and distribution, control techniques, and other power technique programs. Illustrations include load financial institutions, grounding resistors, and dynamic braking resistors.
There are several possible producing techniques but resistors based mostly on thick film technology substrates give large integration density that can make it best for applications in which substantial power dissipation is needed in a modest area. The materials traits of the substrate imply it is an outstanding match with the aluminium substance in heatsinks and it is chemically inert and mechanically steady.
Unique carrier supplies, this sort of as Silicone Nitrite could be utilised to create a energy resistor in the kW range. Even so, these supplies can be expensive and could value as a lot as € 200 every in order quantities of a handful of thousand models, in addition the fees for processing with Thick Film resources. This signifies this sort of materials are generally only utilized for specialists apps.
Illustrations include a power resistor with dimensions a hundred mm by 50 mm on one mm thick Alumina Ceramic that can take care of 500 W provided the aspect temperature is retained consistent at about 60 °C. Resistor load banking institutions with energy rankings as substantial as 25 kW @ 140 kVolts could be produced.
When manufactured appropriately using appropriate components Thick Film energy resistors can deal with several kW of energy dissipation but they produce big amounts of warmth which will fracture the resistor provider plate if not retained under management. Watchful consideration of the software and thermal management is consequently required just before committing to the resistor layout and manufacturing approach.
One resolution to the resistor thermal overload problem is to submerge the power resistor in higher grade mineral oil in a heat exchanger. The exchanger need to be made properly to make sure it is able of removing the warmth generated so the oil temperature is kept continual at a safe level.
Acceptable management of the warmth exchanger is essential as Impurities in the sort of carbon deposits are generated in higher voltage oil cooled programs and except if oil is filtered and / or otherwise retained at large high quality by means of standard replacements, this kind of impurities will build to a degree in which one particular or much more resistors are shorted out of the loop and consequently cause other resistors in the chain to overload and fracture. Yearly oil modifications are for that reason suggested.
A electrical power resistor produced making use of thick movie technologies gives a comparatively low expense, substantial efficiency, little footprint remedy for a extensive variety of power applications. However, watchful thought of thermal issues is needed during the design period to make certain reliable procedure. Learn more about high power resistors here.