The wiring of the Electrical Current Transformer should follow the series principle: that is, the primary winding should be connected in series with the circuit under test, and the secondary winding should be connected in series with all instrument loads. According to the measured current, select the appropriate transformation ratio, otherwise the error will increase. At the same time, one end of the secondary side must be grounded to prevent the primary side high voltage from entering the secondary low voltage side once the insulation is damaged, causing personal and equipment accidents. No open circuit is allowed on the secondary side. In order to meet the needs of measuring instruments, relay protection, circuit breaker failure judgment and fault filtering, etc., 2~ is set in the circuits of generators, transformers, outgoing wires, bus section circuit breakers, bus circuit breakers, bypass circuit breakers, etc. Eight electrical current transformers with secondary winding. The installation location of the Electrical Current Transformer for protection should be set as far as possible to eliminate the unprotected area of the main protection device. In order to reduce the damage caused by the internal fault of the generator, the Electrical Current Transformer used to automatically adjust the excitation device should be arranged on the outlet side of the generator stator winding.