In 1979, TPC (former name: THOMSON-CSF PASSIVE COMPONENTS or LCC) developed the CONTROLLED SELF-HEALING technology for medium power capacitors.In 1988, TPC further evolved the CONTROLLED SELF-HEALING technology for use in impregnated DC filtering capacitors (TRAFIM series). This product range has been a great success with several companies buying the TRAFIM license.
These capacitors made great advances over previous technologies by combining the benefits of the CONTROLLED SELF-HEALING process and superior energy densities due to the impregnation, making it one of the most compact capacitors on the market for 1/2 CV_ values.Due to the oil impregnation with rape seed oil, TPC use the FIM technology to cover a large range of voltage: 1kV up to 70kV for DC filtering and energy discharge.
Today, TPC proposes impregnated capacitors for the discharge applications, on the voltage range: 1.2 kV up to 60 kV, using the same controlled self-healing film technology as used in the TRAFIM series: " DISFIM 3 technology ".
In the past, such discharge capacitors used foil electrodes. Any defect or weak point in the film could provoke the catastrophic failure of the capacitor involving a short-circuit with risk of explosion.
Now, with the CONTROLLED SELF-HEALING, the capacitance is divided into several millions elementary capacitances protected by " fuse gates ". The weak point in the dielectric is now insulated and the capacitors continue functioning normally without short circuit or explosion risk.The capacitor acts like a battery, while working it "consumes " a certain amount of capacitance through the gradual breakdown of the individual capacitance " cells ". Over the life of the capacitor, the capacitance gradually decreases. At the end of the capacitoršs life, we observe a decrease of 2 or 5% in the nominal capacitance.