Shunt Reactors are intended for connecting phase to earth, phase to neutral or between phases in a power system to compensate for capacitive currents.
The absorbed reactive power at rated voltage can be fixed or adjustable by the use of additional means such as –

• Phase controlled switching by power electronic device (such as SVC)
• DC magnetization of iron core
• Winding taps “on load” or “off load” settings.

Transmission cables have much higher capacitance to earth than overhead lines. Long submarine cables for system voltages of 100 KV and more need shunt reactors. The same goes for large urban networks to prevent excessive voltage rise when a high load suddenly falls out due to a failure.

The neutral of shunt reactor may be directly
earthed, earthed through an Earthing-reactor or unearthed.

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