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Electric Power

It covers articles related to single and three phase power.

Types of Protective Relays

The protective relay is the device that responds to signals from the transducers by quickly initiating or allowing a control action to be implemented in order to prevent damage to the faulted equipment and to restore service as soon as possible. The operating characteristics of the more commonly used protective …

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Power System Protection Components

power system protection components

The operation of a power system is affected by disturbances that could be due to natural occurrences such as lightning, wind, trees, animals, and human errors or accidents. These disturbances could lead to abnormal system conditions such as short circuits, overloads, and open circuits. Short circuits, which are also referred …

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Symmetrical Components in Power System

sequence components of voltages

The method of symmetrical components is used to solve power system problems involving unbalanced polyphase voltages and currents. It is analogous to the Fourier analysis of nonsinusoidal wave shapes wherein a non-sine wave is resolved into a number of sine waves of various frequencies. In symmetrical components, the unbalanced set …

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Electrical Power System Components

power system

The electrical power system can be divided into three major components: generation (G), transmission (T), and distribution (D) as shown in Fig. 1. The generating system provides the system with electric energy. Transmission and Sub-Transmission Systems The transmission and sub-transmission systems are meshed networks; that is, there is more than …

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Three-Phase AC Power Calculation

Power relationships in an AC circuit

In a three-phase AC power distribution circuit, three single-phase AC sources are interconnected in either a wye or delta configuration to form a 3-wire supply in the alternator, transformer, or electric motor, and sometimes a 4-wire supply in the alternator or transformer. If the three single-phase AC sources were in-phase …

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Three-Phase AC Power: Star & Delta Connection

Generation of three single-phase AC

The most economical way to mass produce AC power is by steam turbines that drive large three-phase AC generators (alternators — Figure 1). Figure 1. Steam turbines drive large 3-phase AC generators This is why most electrical-utility power generating plants are located on a river that has been dammed to …

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Single-Phase AC Power

Generation of single-phase AC power

In a single-phase (or 3-phase for that matter) AC electrical power distribution system, both the load current (as electrical utilization loads are connected) and the applied voltage that causes it to flow are transmitted along the length of the circuit conductors varying in amplitude with time and periodically reverse between …

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High-Voltage DC Power Transmission

Advantages and disadvantages of a High-Voltage DC power transmission system should be analyzed in detail. Only then can we raise the question: Is AC energy transmission the most efficient option for the 21st century? AC energy transmission is the most common mode of energy transmission in the world. DC transmission …

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Solar Energy System Cost

A general method of calculation will start from the load energy requirements; determine the local insolation level and the worst month insolation and from this determine the sizing of the storage capacity. From this follows the array power and area, the battery capacity, and eventually the voltage regulator size respectively, …

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Harmonics in Power System

Approximation to a square wave using the first five

Ideally, all voltages and currents in the power system should be single-frequency sinusoids (60 Hz in North America). The actual power system, however, contains voltage or current components, called harmonics, whose frequencies are integral multiples of the power system frequency. The second harmonic for a 60 Hz system is 120 …

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Load Profile Calculation | Solved Example

The load profile is an approximation of the aggregate energy required from a power system over a particular time period (e.g., years, days, hours). The load profile is demonstrated in a two-dimension graph exhibiting the instantaneous load (in Volt-Amperes) over a certain period of time and presents an easy way …

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Solar PV System Sizing: Step By Step Guide

solar pv system sizing

This particular article talks about the standalone solar photovoltaic (PV) system sizing. Standalone PV systems are primarily utilized for providing power to small, remote areas where it’s impractical to lay down a transmission line or even have some alternative generation option like diesel generators. Though this article focuses mainly towards …

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