What are the two types of tap changer?
There are two types of transformer tap changers: an on-load tap changer (OLTC) and a deenergised tap changer (DETC).
What is DETC tap changer?
No-load tap changer (NLTC), also known as Off-circuit tap changer (OCTC) or De-energized tap changer (DETC), is a tap changer utilized in situations in which a transformer’s turn ratio does not require frequent changing and it is permissible to de-energize the transformer system.
Where is tap changer located?
A tap changer is usually installed on a high voltage section of a two-winding transformer, due to the low current in that area. The changers are also provided on high voltage windings of an electrical transformer if there is sufficient control of voltage.
How many types of tap changers are there?
two types
There are two types of tap changers: a de-energized tap changer (DETC) and an on-load tap changer (LTC).
What is LTC transformer?
On-load tap changers (LTC, or, OLTC) regulate the turns ratio and thus the voltage ratio of an electrical transformer. Unlike its no-load counterpart, on-load tap changers do this without interrupting the load current. There are two main load tap changer designs, the reactance and the resistive types.
What is LTC in electrical?
Load tap changers (LTCs) play an important role in a substation. These mechanical devices are often overlooked, but a failed LTC will cause problems at its substation and complications through the grid as load is rerouted. LTCs are often tested and maintained by the same crews that test circuit breakers.
Why do we need tap changer in transformer?
The purpose of a tap changer is to regulate the output voltage of a transformer by altering the number of turns in one winding and thereby changing the turns ratio of the transformer.
What is the difference between on load and off load tap changer?
A off-load is a tap changer that cannot be moved while the transformer is energized. On Load Tap Changer we can change the tape on load. But in Off Load we can only operate on no load.
What are the types of bushing?
Types According to Insulation inside Electrical Bushing
- Air-Insulated Bushings.
- Oil-Insulated or Oil-Filled Bushings.
- Oil-Impregnated Paper-Insulated Bushings.
- Resin-Bonded or -Impregnated Paper-Insulated Bushings.
- Cast-Insulation Bushings.
- Gas-Insulated Bushings.
What is a LTC in a substation?
What is off nominal tap ratio?
The off-nominal tap ratio determines the additional transformation relative to the nominal transformation. This value normally ranges from 0.9 to 1.1 (1.0 corresponds to no additional transformation). For phase-shifting transformers the phase shift value normally ranges from about -40° to 40°.
What is LV bushing?
LV MV HV Bushings 1,000V 11kV 33kV Webster-Wilkinson transformer bushings are used in transformers as a means of electrical / mechanical connection from the outside of the tank (cables or overhead lines) to the inside of the tank (transformer windings).
Why bushing CT is used?
The outdoor bushing current transformer (OBCT) is used for relaying and metering on existing power transformers or circuit breakers. The outdoor bushing current transformer is used for relaying and metering on existing power transformers or circuit breakers.
Why breather is used in the transformer?
Transformer Breather Helps to Prevent Atmospheric Moisture and Reduce Maintenance Costs. During the breathing cycle of a transformer, it is crucial to prevent atmospheric moisture from entering the transformer, which can contaminate the oil.
How is tap ratio calculated?
Transformer Tap Calculation
- Normal tap (100% tap) primary voltage [V]* Rated primary voltage from name plate.
- Normal tap (100% tap) secondary voltage [V]*
- Actual primary voltage [V]*
- Nominal tap-internal.
- +7.5% tap-Secondary voltage.
- +7.5% tap-internal.
- +5% tap-internal.
- +5% tap-Secondary voltage.
How many position DTU™ tap changers do I Need?
This order data sheet is for 5 position DTU™ tap changers. For series/parallel and tap changers with a different number of positions, please contact ABB. More detailed information about the type DTU tapchanger can be found in the installation and selection guide 1ZUA4643-210.
What are the appropirate dimensions and unit of measure for tap changers?
Please populate the following fields with the appropirate dimensions and unit of measure: B1 = in or mm B2 = in or mm The B2 dimension is only required for DTUB and DTUC model tap changers
Why choose a tap-changer with fewer parts?
In addition to increased reliability, tap-changers with fewer parts allow for considerable reduction in size and cost. Our tap-changers are matched with trustworthy, rugged motor drives that are configurable to meet a wide range of environmental conditions and customer specifications.
Why choose a vacuum interrupter tap-changer?
Our new generation of tap-changers utilize the most recent vacuum interrupter technology. This design philosophy allows the arcs during load commutations to occur in vacuum interrupters and not in the tap-changer oil. This greatly reduces the need for maintenance and creates the potential for using environmental-friendly insulating fluids.