Why a Reactor is used with a Capacitor Bank?
When a reactor is connected in series with a capacitor bank, it is called a Detuned Reactor. It serves two critical protection purposes:
- Harmonics Mitigation
- Limiting Inrush Current
Harmonics Mitigation
Modern industries use non-linear loads like VFDs, UPS systems, and LED lighting, which inject harmonics (distortions) into the power grid.
Capacitors naturally attract these high-frequency harmonic currents, which can cause them to overheat, swell, or explode.
The reactor acts as a barrier, blocking or absorbing these harmonics to protect the capacitor.
Limiting Inrush Current
When a capacitor bank is switched on, it acts like a temporary short circuit, drawing a massive spike of current known as inrush current.
This spike can weld contactor contacts and trip circuit breakers.
The reactor introduces inductive impedance that chokes and dampens this initial current spike.