As short interruptions are due to automatic switching actions, their recording requires automatic monitoring equipment. Unlike long interruptions, a short interruption can occur without anybody noticing it. That is one of the reasons why utilities do not yet collect and publish data on short interruptions on a routine basis. One of the problems in collecting […]
MONITORING OF SHORT INTERRUPTIONS Read More »
Switchgear covers a wide range of equipment concerned with switching and interrupting currents under both normal and abnormal conditions. It includes switches, fuses, circuit breakers, relays and other equipment. A brief account of these devices is given below. However, the reader may find the detailed discussion on them in the subsequent chapters. 1. SWITCHES A
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The essential features of switchgear are: (I) COMPLETE RELIABILITY With the continued trend of interconnection and the increasing capacity of generating stations, the need for a reliable switch-gear has become of paramount importance. This is not surprising because switchgear is added to the power system to improve the reliability. When fault occurs on any part
ESSENTIAL FEATURES OF SWITCHGEAR Read More »
The apparatus used for switching, controlling and protecting the electrical circuits and equipment is known as switchgear. The switchgear equipment is essentially concerned with switching and interrupting currents either under normal or abnormal operating conditions. The tumbler switch with ordinary fuse is the simplest form of switchgear and is used to control and protect lights
An induction regulator is essentially a constant voltage transformer, one winding of which can be moved w.r.t. the other, thereby obtaining a variable secondary voltage. The primary winding is connected across the supply while the secondary winding is connected in series with the line whose voltage is to be controlled. When the position of one
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When the load on the supply system changes, the terminal voltage of the alternator also varies due to the changed voltage drop in the synchronous reactance of the armature. The voltage of the alternator can be kept constant by changing the field current of the alternator in accordance with the load. This is known as
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In this type of regulator, exciter field rheostat is varied continuously or in small steps instead of being first completely cut in and then completely cut out as in Tirril regulator. For this purpose, a regulating resistance is connected in series with the field circuit of the exciter. Fluctuations in the alternator voltage are detected
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In this type of regulator, a fixed resistance is cut in and cut out of the exciter field circuit of the alternator. This is achieved by rapidly opening and closing a shunt circuit across the exciter rheostat. For this reason, it is also known as vibrating type voltage regulator. CONSTRUCTION OF TIRRIL REGULATOR Figure shows
WHAT IS VOLTAGE CONTROL? In a modern power system, electrical energy from the generating station is delivered to the ultimate consumers through a network of transmission and distribution. For satisfactory operation of motors, lamps and other loads, it is desirable that consumers are supplied with substantially constant voltage. Too wide variations of voltage may cause
DC Ground detectors: are the devices that are used to detect/indicate the ground fault for ungrounded DC systems. When a ground fault occurs on such a system, immediate steps should be taken to clear it. If this is not done and a second ground fault happens, a short circuit occurs. Lamps are generally used for