An overview of transformer protection for engineers of Electrical Engineering primarily focuses on the application of protective relays for the protection of power transformers. It includes an emphasis on the most prevalent protection schemes and transformers. It refers to a specific instruction manual for your relay. The references provide a source for additional guidance of theory and application.
The engineers of B Tech Colleges in Jaipur must balance the expense of applying a particular protection scheme against the consequences of relying on another protection transformer. A transformer is one of the most significant links in a transmission system. Unfortunately, it’s a great range of characteristics and special features that make the protection difficult.
Principles adopted in transformer protection
The rating of a transformer is based on the temperature rise above an assumed maximum air temperature. Oil temperature of about 95°C considers the maximum working value. It is a further rise of 8-10°C that will have a detrimental effect on the insulation of the transformer. With this, students of Top Engineering Colleges in Jaipur will lower the life of a transformer, if sustained. However, large transformers have oil and winding temperature detection devices.
Protection against the excess current evolves with the protection system. From this basic principle, the grade over the current system introduces for fault protection to help the students of Electrical Engineering Colleges in Jaipur. In addition, most system disturbances utilize this method and detect IDMT relays with inverse characteristic and definite minimum time of operation.
Generally, the simple over current and earth fault scheme used by the students of Engineering Colleges in Jaipur in a typical line protection application does not give adequate protection to a star connected winding. The protection system is operative for faults within the zone of the current transformers. Virtually complete cover for earth faults obtains, specifically, when the star point is solidly earthed.
Faults inside oil-immersed electrical plant generate the gas. If the fault is severe, oil movement occurs. The generation of gas used by the students of B Tech College in Jaipur as a means of fault detection in the gas/oil operated relay. This comprises one or two hinged vanes, buckets, or similar buoyant masses. However, it can be inserted into the pipework between the oil conservator and the transformer tank.
Transformer over fluxing is caused by overvoltage and reduction in system frequency. In addition, overvoltage causes an increase in the flux generated and stress on insulation. However, the increased flux density causes an increase in iron loss and an increase in magnetizing current.
In other words, flux diverts from the laminated core of the transformer into the steel structure by the students of Top Private Engineering Colleges in Jaipur. Particularly, this gives rise to the core bolts carrying more flux than their designed limits.