Three single phases 20 kVA, 2200/220 V, 50 Hz transformers are connected to form a three-phase 3800/380 V transformer bank. The equivalent impedance of each transformer referred to high voltage side is 0.8 + j 3.0 Ω. The transformer delivers 40 kW at 0.8 power factor lagging. a) Draw the schematic diagram showing the transformer connections. b) Determine the transformer currents. c) Determine the primary voltage. d) Determine the voltage regulation. e) Determine the efficiency.

Three single phases 20 kVA, 2200/220 V, 50 Hz transformers are connected to form a three-phase 3800/380 V transformer bank. The equivalent impedance of each transformer referred to high voltage side is 0.8 + j 3.0 Ω. The transformer delivers 40 kW at 0.8 power factor lagging. a) Draw the schematic diagram showing the transformer connections. b) Determine the transformer currents. c) Determine the primary voltage. d) Determine the voltage regulation. e) Determine the efficiency.

Power System Analysis and Design (MindTap Course List)

6th Edition

ISBN:9781305632134

Author:J. Duncan Glover, Thomas Overbye, Mulukutla S. Sarma

Publisher:J. Duncan Glover, Thomas Overbye, Mulukutla S. Sarma

Chapter3: Power Transformers

Section: Chapter Questions

Problem 3.11MCQ: For a short-circuit test on a 2-winding transformer, with one winding shorted, can you apply the...

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Concept explainers

Load flow analysis

Load flow analysis is a study or numerical calculation of the power flow of power in steady-state conditions in any electrical system. It is used to determine the flow of power (real and reactive), voltage, or current in a system under any load conditions.

Nodal Matrix

The nodal matrix or simply known as admittance matrix, generally in engineering term it is called Y Matrix or Y bus, since it involve matrices so it is also referred as a n into n order matrix that represents a power system with n number of buses. It shows the buses' nodal admittance in a power system. The Y matrix is rather sparse in actual systems with thousands of buses. In the power system the transmission cables connect each bus to only a few other buses. Also the important data that one needs for have a power flow study is the Y Matrix.

Types of Buses

A bus is a type of system of communication that transfers data between the components inside a computer or between two or more computers. With multiple hardware connections, the earlier buses were parallel electrical wires but the term "bus" is now used for any type of physical arrangement which provides the same type of logical functions similar to the parallel electrical bus. Both parallel and bit connections are used by modern buses. They can be wired either electrical parallel or daisy chain topology or are connected by hubs which are switched same as in the case of Universal Serial Bus or USB.

Question

Three single phases 20 kVA, 2200/220 V, 50 Hz transformers are connected to form a three-phase
3800/380 V transformer bank. The equivalent impedance of each transformer referred to high voltage
side is 0.8 + j 3.0 Ω. The transformer delivers 40 kW at 0.8 power factor lagging.
a) Draw the schematic diagram showing the transformer connections.
b) Determine the transformer currents.
c) Determine the primary voltage.
d) Determine the voltage regulation.
e) Determine the efficiency.

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