Tricky but Easy Electrical Engineering!
Variable Frequency Transformer or simply VFT is quite a new technology to connect two asynchronous Grids. Asynchronous Grids mean two power systems operating at two different frequencies. The world’s first VFT was installed and commissioned in the year of 2004 at Hydro- Quebec’s Langlois substation, where it is used to exchange up to 100 MW … Read more
Low Forward Power means the output of Generator is sufficiently reduced. Low Forward Power Protection is basically a check not a protection i.e. Generator is tripped after having a check that its forward power has reduced. When the machine is generating and the CB connecting the generator to the system is tripped, the electrical load … Read more
A synchronous Generator / Alternator is expected to supply active power to the system in normal operating condition. If the turbine i.e. prime mover fails the Generator / Alternator connected to the system will continue to operate as synchronous Motor drawing active power from the system. This reversal of power flow due to loss of … Read more
Frequency all over a synchronous Power Grid is the same in steady state. Mind the word Synchronous Power Grid, as there may be two different grids operating at slight different frequencies. It is very important to maintaining a constant frequency or to frequency to vary over a very narrow band in a power system operation. … Read more
Dead Machine Protection in a Generator is provided to ensure that Generator is not energized accidentally in standstill condition or when the Generator is on Turning Gear. Accidental energization of Generator when the machine is not running can cause severe damage to the machine. (How? You will be able to answer after you go through … Read more
DC Machines can be tested by three different methods namely Direct Method, Indirect Method and Regenerative Method. Direct Method of testing of DC Machine, also known as Brake Test (if carried out for a DC Motor) will be discussed in this post. Direct method is suitable for small DC machines. In Direct Method, the DC … Read more
In Permanent Magnet DC Motor or PMDC Motor, permanent magnet is used to create the working flux in the air gap instead of field winding. The construction of rotor is same as that of the Conventional DC Motor i.e. rotor of PMDC Motor consists of armature core, armature winding and commutator. Generally, there are two … Read more
The rating of AC Machines such as Transformer, Alternators etc. are determined by the heating and hence losses in them. These losses are made up of Ohmic (I2R loss ) and Core Loss and a small amount of friction & windage loss. The ohmic loss depends upon the current and the core loss depends upon … Read more
Open Circuit Test and Short Circuit Test are performed on a Synchronous Machine to find out the parameters of Synchronous Machine and hence to have an idea of their performance. Open Circuit Test of Synchronous Machine is also called No Load, Saturation or Magnetizing Characteristics for the reason which will be clear after going through … Read more
The transformer which handles voltages and currents in the form of pulse are called Pulse Transformer. Pulse Transformer is mostly used in Power Electronic circuits as an Isolating Transformer to isolate source and load. It is also used in television, radar, digital computers etc. The main functions of the Pulse Transformer are as below: 1) … Read more