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  2. Protective relay - Wikipedia

    en.wikipedia.org/wiki/Protective_relay

    Distance relays, also known as impedance relay, differ in principle from other forms of protection in that their performance is not governed by the magnitude of the current or voltage in the protected circuit but rather on the ratio of these two quantities. Distance relays are actually double actuating quantity relays with one coil energized by ...

  3. Power system protection - Wikipedia

    en.wikipedia.org/wiki/Power_system_protection

    Current and voltage transformers to step down the high voltages and currents of the electrical power system to convenient levels for the relays to deal with; Protective relays to sense the fault and initiate a trip, or disconnection, order; Circuit breakers or RCDs to open/close the system based on relay and autorecloser commands

  4. 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]

  5. A Symbolic Analysis of Relay and Switching Circuits

    en.wikipedia.org/wiki/A_Symbolic_Analysis_of...

    Whereas Shannon's approach and framework was abstract and based on mathematics, Nakashima tried to extend the existent circuit theory of the time to deal with relay circuits, and was reluctant to accept the mathematical and abstract model, favoring a grounded approach. [6]

  6. Impedance control - Wikipedia

    en.wikipedia.org/wiki/Impedance_control

    In theory, an impedance controller can cause the mechanism to exhibit a multi-dimensional mechanical impedance. For example, the mechanism might act very stiff along one axis and very compliant along another. By compensating for the kinematics and inertias of the mechanism, we can orient those axes arbitrarily and in various coordinate systems.

  7. Blackman's theorem - Wikipedia

    en.wikipedia.org/wiki/Blackman's_theorem

    Blackman's theorem is a general procedure for calculating the change in an impedance due to feedback in a circuit. It was published by Ralph Beebe Blackman in 1943, [1] was connected to signal-flow analysis by John Choma, and was made popular in the extra element theorem by R. D. Middlebrook and the asymptotic gain model of Solomon Rosenstark.

  8. 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 ...

  9. Impedance analogy - Wikipedia

    en.wikipedia.org/wiki/Impedance_analogy

    The impedance analogy is a method of representing a mechanical system by an analogous electrical system. The advantage of doing this is that there is a large body of theory and analysis techniques concerning complex electrical systems, especially in the field of filters. [1]