Power transformer differential protection is the main protection for powers transformers, using the principle of circulating current. Differential protection can quickly and selectively activate short-circuit protection in the event of phase to phase short circuit faults in transformer windings, outgoing lines, and single-phase turns.
The basic requirements for transformer differential protection are as follows:
1. High sensitivity and fast reaction speed.
2. Good accuracy.
3. Good stability.
4. High reliability.
5. Strong anti-interference ability.
6. Easy installation and debugging.
The principle of power transformer differential protection is that when the line voltage rises, the current on the line increases due to reasons such as low impedance of the transformer or short circuit grounding. In this case, using a fuse for current limiting will cause the switch to trip; If overload relays are used to limit the load in the circuit, it will cause the motor to burn out the windings and coil edges due to overload, and other equipment damage phenomena will occur. Therefore, other measures need to be taken to control the power system to achieve its safe operation.
The operation process of power transformer differential protection is as follows:
firstly, the relay device determines the fault point based on the signal provided by the measuring instrument and sends an alarm message to the monitoring room and the operator on duty. Then, after processing and analysis, the components and their phases that caused the accident are determined, and this result is fed back to the corresponding electrical workers for processing through communication, in order to ensure the safe and reliable power supply of the power grid.
PowerTel and his factories can provide you a wide range of power transformers, up to 500 kV, and some value-added services, including custom design & fabrication, free delivery to your jobsite, pisitioning & installation, to final testing & commissioning.