The use of a core depends on the reactor application.
Filled with PCB-free oil that has been dried and degassed, and complies with IEC standards.
Made with circular cross-section, with pure cellulose paper conductor insulation.
Corrugated or with radiators made from stamped cold-rolled steel.
Current limiting reactors are used to limit line currents. They are normally used to ensure that fault currents do not exceed the maximum values of the circuit breakers. They are connected in series with the line. They are single-phase coreless coils connected in a three-phase configuration, which can be installed one above the other in a frame, or supplied individually and connected in a three-phase configuration on-site.
Typically in oil, they have a three-phase core with zig-zag winding. This type of reactor is used to create a dummy neutral, which can be connected to earth either directly or through a resistor. The neutral formers are shunt-connected to the line.
These are single-phase or three-phase reactors used to reduce the harmonic content in the mains or inside plants with high voltage distortion. They are connected in series or in parallel with the capacitance (capacitors) on both the LV side and MV side.
Shunt reactors are shunt-connected to long transmission lines to compensate for their capacitance and prevent voltage rises at the end of the line.
Smoothing reactors are connected in series with DC lines that have a current ripple that must be reduced. Smoothing reactors are typically single phase.
These reactors are connected in series with capacitors to shift the resonant frequency to a value that is not dangerous to the capacitors.