Shunt reactors: transformer connections and compensation
A shunt reactor is an inductive element connected in parallel with the system. It helps balance capacitive reactive power. Its reactive-power effect is opposite to that of a capacitor bank.
When is it considered?
Long transmission lines and cable systems can produce capacitive reactive power. A shunt reactor can compensate for this effect. Its rating and operating strategy depend on the network’s different operating conditions.
How can it connect to a transformer?
Hitachi Energy describes connections directly to a line or to the tertiary winding of a three-winding transformer. Reactors can be permanently connected or switched by a circuit breaker. A tertiary connection is a system-design choice; not every transformer has a suitable tertiary winding.
Do not confuse it with a series reactor
A series reactor in a capacitor bank changes the branch’s frequency behavior. A shunt reactor is a parallel inductive reactive-power element. Transformers, shunt reactors and capacitor banks have distinct functions.
What determines selection?
Instead of applying a fixed percentage of transformer rating, establish the connection point and the system’s capacitive reactive-power requirement. Evaluate voltage, operating scenarios and switching behavior. A single-line diagram, cable information and measurement records are useful starting inputs.
A shunt reactor does not supply a transformer’s inductive magnetizing requirement as a capacitor would. Measurements must distinguish inductive and capacitive requirements.
Hitachi Energy — Shunt reactors ↗
Schneider Electric — Reaktörlü kapasitör bankları ↗
This content provides general information. Electrical installation work requires assessment by qualified technical personnel.
Explore this topic for your installation.
Share your existing system and technical question to discuss consulting.
Request a technical assessment ↗