Tag: Power systems
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Protective Relays: Function, Features & Operation
A protective relay is basically an electrical device that detects a fault in a power system and initiates the operation of the circuit breaker to isolate the defective section or component from the rest of the system. In other words, the prime function of protective relays is the timely and discriminative clearance of system faults.…
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SF6 Circuit Breakers: Features, Operation & Applications
Introduction Many modern designs of circuit breakers for use at transmission voltages utilize sulphur hexafluoride (SF6) gas both as an arc-interrupting/arc-quenching and a dielectric medium. At distribution voltages SF6 designs of circuit breakers are also used, however vacuum and bulk-oil circuit breakers still find a wide use as alternatives. The SF6 is an electron-negative gas…
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Main Types of Earthing Systems
Introduction The process of connecting the metallic frame i.e. non-current part of electrical equipment or some electrical part of the system such as the neutral point of the secondary side of the distribution transformers or the star point in a star connected system to the earth is called grounding or earthing. The potential of the…
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Common Causes of Failures of Power Transformers
As with most of electrical equipment, the key causes of failure of power transformers are either due to electrical failure or mechanical failure. These failures don’t occur that often as compared with other failures in other electrical equipment like switchgear. Common failures of power transformers and their causes are discussed in the following sections. Typical…
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Three-Phase Diode Bridge Rectifier: Function & Operation
In many high-powered applications, three-phase voltages need to be rectified to give rise to a single DC supply; such rectification can be accomplished using an extension of the bridge rectifier such as the three-phase diode bridge rectifier. Let’s consider the balanced three-phase circuit shown in Figure 1.0 below; the three-phase wye-connected source is connected to…
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Testing Power and Distribution Transformers
The typical practice for testing power and distribution transformers is to carry out a comprehensive set of tests at the manufacturer’s works. The number and nature of the tests depend on whether the transformer is the first of a new design or not, additionally a few relatively simple tests are done after installation at site…
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Major Technologies for Smart Grid Implementation
Smart grid can enhance legacy electric systems (i.e. the traditional electricity infrastructure) by improving reliability and security; additional smart grid can offer economic benefits and cost savings, environmental improvement, and so forth. Generally smart grid represents the integration of digital technologies, sensors and other information and communication technologies to enable more efficient and reliable electricity…
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What Is the Difference between Photovoltaic Panels Parallel & Series Connection?
Photovoltaic panels differ in their ability to connect components. Photovoltaic cells can be combined in two ways: parallel and series. Each has different features, such as how to connect photovoltaic panels. What are the characteristics of both types of modules? Methods of connecting photovoltaic panels Each photovoltaic installation consists of one or several rows of…
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Features and Classification of Substations
A substation can be defined as an assembly of apparatus used to change some characteristics like voltage, AC, DC, frequency, power factor, etc., of electric supply. Substations play a key role in power systems. The continuity of supply depends largely upon the successful operation of substations. Thus, it is imperative to exercise utmost care while…
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How cycloconverter is used as a direct frequency converter
The cycloconverter provides direct ac to ac transformation with control over both the output voltage magnitude and output frequency. It employs phase-angle-controlled bridges to synthesize voltages. The most common form is the three-phase to three-phase converter illustrated below: Each output needs two three-phase thyristor bridges. One bridge is used to synthesize positive voltages at the…