Ac capacitors - Import export

The custom-tailored capacitors of our E70 series are mainly applied for power factor correction or as resonance capacitors in induction furnaces that are operated at mains frequency (50/60Hz). The E70 are made alternatively in two designs: Inside the steel case, there is a large number of individual self-healing capacitors, each one of them protected by its own break-action mechanism. In the event of a failure, the affected element is disconnected separately while the capacitor as a whole continues to function with slightly decreased total capacitance. Windings assembled inside a hermetically sealed metal case, filled with solid resin, and protected by a pressure sensor similar to the capacitors of our ranges E56/E59.

In power electronics in general, and especially in low inductance buffer circuits with higher voltages as well as in discharge circuits, the call for capacitors with low inductance tends to pose problems: traditional high voltage capacitors are filled with oil, and the generous bushings required for clearance and creepage as well as internal safety mechanisms add substantially to the self-inductance of the capacitor. Based on decades of proprietary experience in metallizing capacitor films, ELECTRONICON has created a range of high voltage capacitors in self-healing technology, using the opportunities of special metallizing patterns. Despite the high voltage rating, our E51 range is manufactured in dry technology and without expensive bushings. Inside the can made of self-extinguishing plastic, the capacitor element is enclosed in solid resin (PUR). Connection is made through robust flat terminals with internal thread.

In modern applications of power electronics, AC capacitors are among the most critical links in the chain of components when it comes to long operating life, safety and reliability of operation. Decades of proprietary ELECTRONICON experience in metallizing capacitor films and designing high-end capacitors have created our very own Know-How, for instance in special metallizing patterns, our SINECUT slitting technology and optimized winding geometries. This enables us to design AC capacitors with a high specific ratio of capacitance to volume, high AC-voltage load capacity and outstanding suitability for high rms and surge currents. The cylindrical capacitors of our universal AC/DC series "E62" are perfect for non-sinusoidal voltages and pulsed currents, e.g. as damping or commutation capacitors switched in parallel to a thyristor, or connected in series with a resistor (damping of undesirable voltage spikes during the switching of power semiconductors).

Who said it has to look like a surge capacitor? They look different, and as a matter of fact, they are. Surge protection capacitors are designed to protect high voltage motors and transformers from events with high transient overvoltages (e.g. lightning or switching surges). Keeping with our tradition of completely dry products, we have designed the first MV Surge Capacitor in self-healing technology: DSCTM In combination with the PD-free layout, the self-healing dielectric provides for extremely long operating life and highest operational safety. Unlike traditional oil-filled ALLFILM-capacitors which are bound to fail as soon as overvoltage or other stress factors have provoked a dielectric breakdown, the self-healing dielectric of DSCTM insulates the breakdown spot immediately and continues operation as usual.

AC capacitors require a hermetical casing in order to operate safely and without processes of chemical corrosion. The latter would result in deterioration of metal coating, decrease of capacitance as well as rise of loss factor and – consequentially – failure of the capacitor. DC capacitors – even though less sensitive to humidity – may suffer from excessive operating conditions as well. Another serious issue is the operation in conditions of extreme heat, and there are situations where placement in a cooling liquid is the only way. Certain high voltage applications may require the immersion of all components in insulation oil, such as MIDEL. Quite a few cooling or insulation oils behave aggressively towards metallized polypropylene, causing swelling of the film and deterioration of the contact layers. They must therefore be kept away from the capacitor elements. In the past, mostly MKV capacitors (with oil-impregnated paper electrodes) had to be used in such situations.

E53 and E55 capacitors have a particularly low series resistance and high pulse strength. Using sophisticated metallizing patterns, our SINECUT slitting technology and clever winding geometries, they are especially suited for the damping of GTO thyristors and low-inductance buffer circuits with high rms currents. Along with their very good ratio of capacitance to volume, these components do also have very good self-healing characteristics without loss of capacitance. Their very low self-inductance makes them suitable for use in high-current applications with medium frequencies. The capacitors of the E53 product family are housed in flame-retardant plastic cans (V0) and filled with solid resin. Special care has been taken both in terms of design and conservative electrical rating to ensure reliable operation even under tough environmental conditions. Connection is usually made through robust axial terminals with internal thread.

Our capacitors of the E12 and E33 series are universally-suited for lighting and motor applications as well as power factor correction and power electronics. Their winding element of self-healing polypropylene film is immersed in eco-friendly vegetable oil and designed for highest requirements regarding operational life and functional safety even at high operating temperatures and other extreme conditions such as high humidity. Connection is made through tab connectors. The hermetical aluminium can is provided with an integrated overpressure safety mechanism (break-action mechanism, " BAM ") that disconnects the capacitor irreversibly from the supply in the event of a failure. The E12/E33 ranges comply with the "Type B" classification under lighting standard IEC/EN61048 as well as with "Class P2" under motor capacitor standard IEC/EN 60252-1. Please mind our safety remarks on the use of lighting capacitors in critical environment.

Thanks to the special kind of films and coating patterns used in our E56/E59-capacitors, clever winding geometries and refined internal construction, they unite large capacitance, very small self-inductance and high surge current sustaining capability (up to 700kA) as well as the possibility of high rms currents (up to 750A). Instead of flat pack windings, our capacitance is formed by compact cylindrical windings, avoiding the mechanical stress and instabilities at the edges of flat packs. Special terminals allow for additional reduction of the self-inductance. At the same time, they are extremely overvoltage-proof. They are especially suited for buffer storage circuits of converters, filter circuits and such like. The capacitors are housed in aluminium or steel cases and filled with solid resin which makes them absolutely dry and leakage-proof. Their shape and dimensions can be adapted to the individual requirements of our customers.