Capacitors of type SM and SMA
Capacitors of type SM and SMA
In the process of network development of high-voltage electricity transmission lines, an increase of their extension and equipping with automatic devices, it arises the need in reliable dispatching, administrative and economic communication between separate points, transmission of telemetry signals, emergency cutting off of switches, relay protection and other data. Usually that kind of communication is transmitted directly along high-voltage electricity transmission lines at a frequency of 40-500 kHz. One of the elements of equipment of such communication is coupling capacitors that separate coupling devices from high voltage of frequency 50 Hz passing signals of high frequency along communication channels. On the basis of same capacitors the devices are made for taking off the power at a frequency of 50 Hz directly from electricity transmission lines for supply of measuring instruments and power equipment as well as measuring devices (dividers, voltage transformers) for voltage measuring of electricity transmission lines.
Capacitors are made with an application of film dielectric. In agreement with the customer it is possible to manufacture capacitors for voltage 110/√3 kV with a paper-film dielectric. In this case, the letters “BP” are in the designation of capacitor type.
Coupling capacitors are impregnated with ecologically safe fluid which is not in a prohibited list of Stockholm Convention about persistent organic pollutants (2001 year).
Application:
* for securing of high-frequency communication at frequencies from 24 up to 1500 kHz in electricity transmission lines with AC rated voltage 35, 110, 150, 220, 330, 500 kV frequency 50 and 60 Hz.Capacitors are produced in porcelain insulators and impregnated with ecologically safe fluid.**for connection of communication devices to electricity transmission lines from 6 up to 35 kV and lightning protection cables.***for high-frequency trap installation;**** capacitor of suspended performance for an active electrical power take-off from 50 Hz alternating current networks with a voltage 110 kV.
- In capacitors designation first number after type – rated voltage in kV;
- second – capacitance in nanofarad;
- C – coupling capacitor;
- M – impregnation with oil;
- B – category of electrical equipment as per external insulation;
- V – with terminal;
- P – combined with insulating support;
- M – capacitors are made in metal cases;
- BP – paper-film dielectric.
