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  2. Distribution transformer - Wikipedia

    en.wikipedia.org/wiki/Distribution_transformer

    In this case, single-phase distribution transformers are used. [5] The number of customers fed by a single distribution transformer varies depending on the number of customers in an area. Several homes may be fed from a single transformer in urban areas; depending on the mains voltage, rural distribution may require one transformer per customer.

  3. Characteristic impedance - Wikipedia

    en.wikipedia.org/wiki/Characteristic_impedance

    The input impedance of an infinite line is equal to the characteristic impedance since the transmitted wave is never reflected back from the end. Equivalently: The characteristic impedance of a line is that impedance which, when terminating an arbitrary length of line at its output, produces an input impedance of equal value. This is so because ...

  4. Short-circuit test - Wikipedia

    en.wikipedia.org/wiki/Short-circuit_test

    A different form of short-circuit testing is done to assess the mechanical strength of the transformer windings, and their ability to withstand the high forces produced if an energized transformer experiences a short-circuit fault. Currents during such events can be several times the normal rated current.

  5. Electrical impedance - Wikipedia

    en.wikipedia.org/wiki/Electrical_impedance

    In electrical engineering, impedance is the opposition to alternating current presented by the combined effect of resistance and reactance in a circuit. [1]Quantitatively, the impedance of a two-terminal circuit element is the ratio of the complex representation of the sinusoidal voltage between its terminals, to the complex representation of the current flowing through it. [2]

  6. Prospective short-circuit current - Wikipedia

    en.wikipedia.org/wiki/Prospective_short-circuit...

    The resistance path is the total resistance back through the supply transformer; to measure this an engineer will use an "earth fault loop impedance meter". The application of a low voltage allows a small current to pass from the socket back through earth to the supply transformer and distribution board.

  7. Impedance parameters - Wikipedia

    en.wikipedia.org/wiki/Impedance_parameters

    For a generic multi-port network definition, it is assumed that each of the ports is allocated an integer n ranging from 1 to N, where N is the total number of ports. For port n , the associated Z-parameter definition is in terms of the port current and port voltage, I n {\displaystyle I_{n}\,} and V n {\displaystyle V_{n}\,} respectively.

  8. Open-circuit test - Wikipedia

    en.wikipedia.org/wiki/Open-circuit_test

    The open-circuit test, or no-load test, is one of the methods used in electrical engineering to determine the no-load impedance in the excitation branch of a transformer. The no load is represented by the open circuit, which is represented on the right side of the figure as the "hole" or incomplete part of the circuit.

  9. Per-unit system - Wikipedia

    en.wikipedia.org/wiki/Per-unit_system

    The ratio of the voltage bases on either side of a transformer is selected to be the same as the ratio of the transformer voltage ratings. With these two rules, a per-unit impedance remains unchanged when referred from one side of a transformer to the other. This allows the ideal transformer to be eliminated from a transformer model.