Triangular Pt action of generator opening

Your generator must be a 6-35kV system.

In our country, in order to improve the reliability of power supply, 6-35kV system adopts the wiring mode of ungrounded system, that is, if the line or system is grounded, it can continue to operate for 2 hours.

This requires that when the secondary winding on the secondary side of the voltage transformer is formed into an open triangle, when a single-phase grounding fault occurs, the voltage will appear at the opening, drive the relay to send grounding alarm and other signals to inform the operators that a single-phase grounding has occurred, and inform the relevant personnel to deal with it in time. If the fault cannot be eliminated within 2 hours, power off again.

The connection method is to connect the three phases end to end, but the head of the first phase and the tail of the last phase are not connected together to form an opening. When the three phases of the circuit operate normally, the vector sum of the opening is zero, so the voltage vector sum of the opening is 0. When there is grounding in the circuit, when the vector sum of the three-phase voltage is not zero, there will be voltage generation and drive the relay to act to send a signal.