C-CAP Power Capacitors Run Cool at High Power Densities Over 2000kVArAugust 26, 2019 by EE Power Editorial
This article features Celem water-cooled C-Cap capacitors compensate for electromagnetic fields to reduce power dissipation and increase power density.
Celem's co-axial, water-cooled C-Cap capacitors (distributed by Eurocomp) compensate for electromagnetic fields that significantly reduce power dissipation and increase power density, resulting in more kVAr per volume.
Celem's C-Cap capacitors have a unique patented structure that prevents the occurrance of hot spots thus enabling to double the allowed power density per capacitor.
Besides its low losses and double the power density, C-Cap enables easy tapping for switching between capacitance values, it features an easy mounting from one side of a very simple bus bar assembly.
C-Cap comes in various values of capacitances and voltages, ranging up to 85uF in a single capacitor and up to 3600Vrms in a single capacitor.
For customers who want to easily test the C-Cap benefits, Celem can supply two turnkey mounting systems to mount the capacitors in parallel or in a serial-parallel combination. Both models of the mounting system allow hot-swapping of capacitors and include an integrated water cooling system.
In addition, Celem has developed a very simple modular mounting system for the above-mentioned capacitors. This modular assembly can accommodate from a few to a hundred capacitors in various parallel and series combinations. Logic-controlled switches can be used to switch on and off any capacitors of the modular mounting system.
Since 2019, Celem has added a new feature to all C-Cap capacitors. Each C-Cap is equipped with a simple, robust, normally closed thermal switch that allows direct monitoring of the capacitor core temperature. In case of overheating above 55 degrees, the thermal switch will open.
This simple function ensures that capacitors are properly cooled, eliminating the need for indirect, complicated and fault-prone instruments (such as water flow and temperature sensors).
The thermal images show in comparison capacitors type C500T 6.3 μF with the capacitors C-CAP 02 12 6.3 μF (both capacitors have exactly the same capacitance element):
Pictures on the left and in the middle show that at 66 kHz and 500 kVAr the temperature of the C-CAP is 24.5 ° C lower than the C500T. The image on the right shows that even at doubled power of 1000 kVAr, the C-CAP is cooler than the C500T at 500 kVAr.
Celem, a family-owned business, was established in 1963 with the goal of designing, producing and marketing innovative, high-quality and reliable high-frequency power capacitors for Induction Heating applications. Celem’s proprietary mica-based technology and patented conduction-cooled technology enable high currents to be generated in a much smaller unit than possible with traditional oil-filled capacitors.