Electric Power Distribution System Basics

A one-line diagram for an electric power distribution system is an electrical drawing that uses single lines and graphic symbols to illustrate the current path, voltage values, circuit disconnects, fuses, circuit breakers, transformers, and panelboards. One-line diagrams use the most basic symbols because the intent of the drawing is to …

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Electrical Power: Transmission & Distribution | Distribution Substation Components

Electrical Power: Transmission & Distribution

Today, most electrical power is distributed through a network of transmission lines (conductors), substations (transformers), and generating equipment from relatively large, centralized power-generating stations directly to the customer. These large, centralized power-generating stations are located near abundant energy sources such as coal, oil, and natural gas. Large, centralized power-generating stations …

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Nodal Analysis with Solved Examples

nodal analysis

Nodal analysis is a circuit-analysis format that combines Kirchhoff’s current- law equations with the source transformation. Converting all voltage sources to equivalent constant-current sources allows us to standardize the way we write the Kirchhoff’s current-law equations. For nodal analysis, we consider source currents to flow into a node. If the …

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Mesh Current Analysis with Solved Problems

Mesh Current Analysis is a technique that simplifies and speeds up writing the simultaneous equations for solving various resistance networks. The format for mesh equations is straightforward, but it cannot handle some of the networks that we can solve with the loop procedure. A mesh is a closed loop that …

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Source Transformation Example Problems with Solutions

source-transformation-1

Source transformation is a circuit analysis technique in which we convert voltage source in series with resistor into a current source in parallel with the resistor and vice versa. For a given constant-voltage source, Rint in the equivalent constant-current source has the same value but appears in parallel with the ideal current source, …

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Three-Phase Electricity Explained

Three-Phase Electricity Explained

In Figure 1 a single load connected to a source constitutes a simple circuit. The source is represented by a winding because all generators have windings in them. Figure 1 A single circuit consisting of a source and a load. Figure 2 illustrates three of these assumed AC circuits near each other. Intentionally, the generators …

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Parallel RLC Circuit: Analysis & Example Problems

parallel-rlc-circuit

In parallel RLC circuits the three basic components are in parallel with each other, and, therefore, all are subject to the same voltage. The current for each branch, however, depends on the impedance of the branch and can be individually determined by employing Ohm’s law. For a parallel RLC circuit, the voltage is common …

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Capacitors in AC Circuits

Capacitors in AC Circuits

When a capacitor is subject to a voltage across its terminals, it starts charging until its charge becomes at the level of the applied voltage. During the time that charging takes place a current flows in the circuit (wires connecting the capacitor to the power source). This current is due to …

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Inductors in AC Circuits

Inductors in AC Circuits

When a coil of wire (an inductor) is connected to DC electricity (Figure 1), a current is building up from zero, making a magnetic field. The wire, itself, is in that field, and therefore, a voltage is generated in it. This generated voltage is in the opposite direction of the …

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Inductors in DC Circuits

Inductors in DC Circuits

Figure 1 illustrates a simple DC circuit consisting of a resistor with which an inductor is added in series. We are interested to see what the effect of this inductor to the circuit is. The effect of an inductor in an electric circuit is always to oppose a change in the …

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