Tricky but Easy Electrical Engineering!
What is Penalty Factor? Penalty Factor in Power System is a factor (greater than unity) by which the incremental cost of power production of plant must be multiplied to accommodate for the transmission losses. It is also defined as the ratio of power generated by the plant to the actual power demand of the load … Read more
PRD Spurious actuation is a case in which transformer tripping is initiated by PRD contacts even when transformer is healthy. Ideally PRD is the last line of defense and actuates when the pressure of oil increases beyond the setting value of PRD. But its spurious actuation results in transformer tripping and may lead to power … Read more
Harmonics in electrical system is the signal having frequency which is integral multiple of fundamental frequency. This means, if the frequency of fundamental component is 50 Hz, then the frequency of harmonics will be 2×50 (=100 Hz), 3×50 (=150 Hz) and so on. If the frequency of harmonics is even multiple of fundamental frequency then … Read more
Start Delta Starter is a scheme for motor starting to reduce the inrush current during starting of the motor. This method of starting is quite popular for Delta connected Squirrel Cage induction motor. In this method, the motor is first started as a star connected motor and as soon as the motor reaches near to … Read more
Power Angle Curve of Synchronous Machine is the graphical representation of electrical output with respect to the power angle. As we know, power angle is also known as load angle, therefore it can be said that this curve is graphical representation of electrical output of generator with respect to load angle. In this article, we … Read more
Load Angle in synchronous machine is defined as the angle between the filed mmf or flux and the resultant air gap mmf or flux. Load angle and power angle are same thing which are used synonymously. There are basically three different types of flux in a rotating electrical machine: Stator flux, Rotor flux and Resultant … Read more
Equation of power flow through an inductive load provides the relationship between the sending end voltage, receiving end voltage, line parameters viz. inductance and resistance of line and the impedance angle. The equation is general and can be well applied for Synchronous generator,Synchronous Motor and Transmission Line with slight but appropriate changes. In this post … Read more
If you ever have seen the setting of Differential Protection of Transformer, you might have noticed two settings shown as Is-HS1 (called High Set 1) and Is-HS2 (called High Set 2). In this post I will be discussing about the significance of these two parameters and its calculation for transformer differential relays. High Set 1(Is-HS1) … Read more
CT Matching Factor is basically a multiplication factor by which secondary current of CTs on HV side and LV side is multiplied to make it equal to rated secondary current. This means, if the rated CT secondary current is 1A, then multiplication of CT secondary current by matching factor will give unity. To get this … Read more
Whenever the load current requirement is more than the current carrying capacity of a single SCR, two or more SCRs are connected in parallel to form a string. By having parallel connection of SCR, it is expected that individual SCR shall share load current equally and hence the string efficiency is unity. But there are … Read more