Short-circuits can be defined according to three main characteristics: – Their origin: They may be mechanical: breakdown of conductors or accidental electrical connection between two conductors via a foreign body such as a tool or animal. They may be electrical: following the degradation of the insulation between phases, or between
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In the motoring operation the d.c. machine is made to work from a d.c. source and absorb electrical power. This power is converted into the mechanical form. This is briefly discussed here. If the armature of the d.c. machine which is at rest is connected to a dc source then,
In the case of a hetero-polar generator the induced emf in a conductor goes through a cyclic change in voltage as it passes under north and south pole polarity alternately. The induced emf in the conductor therefore is not a constant but alternates in magnitude. For a constant velocity of
Homopolar generators Even though the magnetic poles occur in pairs, in a homopolar generator the conductors are arranged in such a manner that they always move under one polarity. Either North Pole or South Pole could be used for this purpose. Since the conductor encounters the magnetic flux of the
D.C. machines are the electro mechanical energy converters which work from a d.c. Source and generate mechanical power or convert mechanical power into a d.c. power. These machines can be broadly classified into two types, on the basis of their magnetic structure. They are, 1. Homopolar machines 2. Heteropolar machines.
Service main is the path between the utility company and consumer. Service mains used are the cables, almost PVC cables are used. Power loss through the PVC cables is an important factor, through which it is analysed and estimated that how much percentage of the power is utilised by the
In renewable energy sources Power quality of distribution system can also be affected by non-linear loads.Non-linear loads are a source of harmonic currents.Renewable energy sources do not directly supplies AC power to the consumers.Renewable sources generate DC power which is then converted to AC with the help of electronic based
Solar photovoltaic (PV) cells and wind mill dependent on climatic change to work and generate electrical energy. Therefore, when these energy sources working alone they are not good power supply. Emerging of solar and wind sources are more valued in electrical energy generation. Such a type of system is called
Equipments are designed for operation at a fixed frequency called fundamental frequency.Harmonics are waveforms of the frequencies which are integral multiples of fundamental frequency. As per the calculations of the harmonics they are defined in the odd and even harmonics. However odd harmonics are important to know. Odd harmonics are
It can be distinct as “Power problems existing in voltage, current or frequency variation that result in failure of consumer’sequipment”. There are a lot of ways inside power supply can be of poor power quality. It is vital to know the different types of power quality variations that can cause
