The substations have current and voltage transformers designed to segregate electrically the high voltage primary circuit from the low voltage secondary circuit and, consequently, offer a safe means of supply for signifying instruments, meters, relays and so on.
1) Current Transformer:
Current transformers are utilized in power installations for supplying the current circuits of indicating instruments (i.e., ammeter, watt-meter, and so forth), meters (i.e., energy meter, and so forth) and protective relays. Such transformers are designed to offer a standard secondary current output of 1 or 5 A, whenever rated current flows via the primary. The fundamental feature of CT is its transformation ratio, symbolized since a ratio of the rated primary to rated secondary current. Current transformers have two inherent errors, that is, the current ratio and phase displacement. Such two errors serve as a basis on which current transformers are categorized for accuracy.
2) Voltage Transformer or Potential Transformer:
Such instrument transformers are utilized for supplying the voltage circuit of indicating instruments, integrating meters, other measuring tools and protective relays or trip coils. Such might be of single phase or three phase design and of the dry or oil immersed kinds. The voltage transformer or PT is rated in terms of the maximum burden (i.e., VA output) it will deliver without exceeding particular limits of error. Instead a power transformer is rated through the secondary output it will deliver without exceeding particular temperature increase. All voltage transformers are designed for a standard secondary voltage of 110 V or 110 / 3 V.
With an invasion of internet, web based Electrical Assignment Help eradicates all complexities of business development and they offers perfect responses for all dilemma. At the present time numerous providers offer Electrical help to the student, therefore they will uplift their knowledge and scores good grades.
Comments
Post a Comment