Electrical Power Engineering Archives

Instrument Transformers – Definition, Types and Errors

Capacitor Potential Transformer Circuit Diagram

Instrument Transformers – Definition, Types and Errors: AC type protective relays are actuated by current and voltage supplied by current and potential (or voltage) transformers, known as instrument transformers. The main function of instrument transformers are: To provide insulation against the high voltage of the power circuit and to protect the apparatus and the operating …

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Overlapping Zones of Protection

Electrical Power Engineering

Overlapping Zones of Protection: Overlapping Zones of Protection – In order to provide selectivity to the system it is usual practice to divide the entire system into several protection zones. When a fault occurs in a given zone, then only the circuit breakers within that zone will be opened and thus only the faulty element …

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Basic Requirements of Protection System

Electrical Power Engineering

Basic Requirements of Protection System: Protection system is an extremely important part of the power system as it is provided to operate under abnormal conditions to prevent failure or isolate trouble and limit its effect. Every protection system which isolates a faulty element is required to satisfy four basic requirements: (i) reliability; (ii) selectively; (iii) …

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Why we need for Power System Protection?

Electrical Power Engineering

Why we need for Power System Protection? Need for power system protection are growing fast with more generators, transformers and large network in the systems. For system operation a high degree of reliability is required. In order to protect the system (lines and equipment) from damage due to undue currents and/or abnormal voltages caused by …

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Sources of Fault Power

Electrical Power Engineering

Sources of Fault Power: The sources of fault power originate in all the generating and other connected plants which under normal operating conditions draw power from the system. Mainly there are three sources which can feed into the short circuit; they are: Generators. Synchronous motors and synchronous condensers. Induction motors. 1. Generators as a Source …

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Effects of Short Circuit Faults on Power System

Electrical Power Engineering

Effects of Short Circuit Faults on Power System: Depending upon power circuit voltage and configuration, method of neutral connection, presence of regulating devices and the speed of disconnection of the faulted circuit section, various types of short circuits may differently influence the power system as a whole. It is well known that the flow of …

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What is Short Circuit Current? – Definition and its Process

Electrical Power Engineering

Process of Change in a Short-Circuit Current

What is Short Circuit Current? – Definition and its Process: Whenever a short circuit current occurs in a power network, it causes heavy current to flow in the network. Figure 1.1 shows how a short-circuit current varies on occurrence of a short-circuit fault. During the first moment of the fault the current attains its maximum …

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Different Types of Faults in Power System

Electrical Power Engineering

Frequency of Fault Occurrence in Different Links of a Power System

Different Types of Faults in Power System: A fault in an electrical equipment/apparatus is defined as a defect in the electrical circuit due to which current is diverted from the intended path. The nature of a types of faults in power system simply implies any abnormal condition which causes a reduction in the basic insulation …

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General Characteristics of Electrical Equipment

Electrical Power Engineering

General Characteristics of Electrical Equipment: All electrical machines, apparatus and other forms of characteristics of electrical equipment must satisfy two main requirements—they must be able to operate continuously under normal service conditions and must be able to withstand short-time overcurrents and overvoltages such as may arise during emergent conditions. For operation of electrical machines and apparatus …

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Methods of Ventilation and Cooling of Electrical Machines

Electrical Power Engineering

Induced Ventilation in Electrical Machine

Methods of Ventilation and Cooling of Electrical Machines: It is necessary to provide suitable ventilation and cooling of electrical machines so that the temperature rise at any part of the machine does not exceed the permissible limit governed by the type of insulation employed in the construction. The cooling of electrical machine by means of …

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