AC Capacitors for Power Electronics
V1 – New Solution for a Traditional Challenge
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.
Our new patented V1 design (E60 series) has been developed by our engineers for exactly these situations: by its outer look resembling our classical PK16™ capacitors, V1 is completely hermetical. Thanks to that, all capacitors in V1 design are rated climatic class C: they can sustain up to occasional 100% relative humidity and 95% as annual means, even at high ambient temperatures. Other than lower climatic classes (such as F or G), condensation is permitted on these capacitors. And our capacitors in V1 design can be operated in insulating or cooling oil.
Just like PK16™, large creepage and clearance distances against the case are provided by the plastic head. The robust terminal studs are separated from each other by a plastic shield where necessary. Fixation can be arranged by the M12x16 mounting stud, or by clamps (not included).
V1 allocates almost as much capacitance per DC voltage rating as an equivalent PK16™ (approx. 85%), self-inductance and series resistance are approximately on the same levels. And it offers more than that: it opens up the way to cylindrical AC capacitors with low series resistance and low self-inductance, suitable for AC filters exposed to high frequencies and harsh operating conditions.
Currently, the E60 AC series ranges from 420 to 3400VAC (300V … 2400Vrms), with capacitances up to 1mF. DC ratings range up to 4250V.
Connection and mounting instructions E50/E51/E53/E54/E55
Capacitors for Power Electronics - Application Notes - Selection Guide (English/German)
Joint Safety Data Sheet of the Power Capacitor Manufacturers associated in the ZVEI (German Associat)