This International Standard applies to capacitors for power electronics intended to be used on rolling stock.
The rated voltage of capacitors covered by this part is limited to 10000 V.
The operating frequency of the systems in which these capacitors are used is usually below 2 500 Hz, while the pulse frequencies may go up to several thousand hertz, in some cases beyond 10000 Hz.
It distinguishes between a.c. and d.c. capacitors.
They are considered as components mounted in enclosures.
NOTE - This standard covers an extremely wide range of capacitor technologies for numerous applications: overvoltage protection, d.c. and a.c. filtering, switching circuits, d.c. energy storage, auxiliary inverters, etc.
The following are excluded from this standard:
- capacitors for induction heat-generating plants operating at frequencies between 40 Hz and 24000 Hz (see IEC 60110);
- capacitors for motor applications and the like (see IEC 60252);
- capacitors to be used in circuits for blocking one or more harmonics in power supply networks;
- small a.c. capacitors as used for fluorescent and discharge lamps (see IEC 61048 and IEC 61049);
- capacitors for suppression of radio interference (see IEC 60384-14);
- shunt capacitors for a.c. power systems having a rated voltage above 1000 V (see IEC 60871-1 and IEC 60871-2);
- shunt power capacitors of the self-healing type for a.c. systems having a rated voltage up to and including 1000 V (see IEC 60831-1 and IEC 60831-2);
- shunt power capacitor of the non self-healing type for a.c. systems having a rated voltage up to and including 1000 V (see IEC 60931-1 and IEC 60931-2);
- electronic capacitors not used in power circuits (see IEC 60080 and IEC 60166);
- series capacitors for power systems (see IEC 60143);
- coupling capacitors and capacitors dividers (see IEC 60358);
- capacitors for applications requiring energy storage/high current discharge such as photocopies and lasers;
- capacitors for microwave ovens. Examples are given in clause 6.
IEC 61881:1999 history
1999IEC 61881:1999 Railway applications - Rolling stock equipment - Capacitors for power electronics