## Difference between Locked Rotor Current and Starting Current

Locked Rotor current and Starting current of induction motor seems to be the same thing at first glance but it is not so. These are two different terms having different meaning and significance. In this post we will discuss the difference between the locked current...

## Penalty Factor – Definition, Formula and Solved Examples

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...

## How to Prevent Transformer Trip due to PRD Spurious Actuation?

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...

## Difference between Harmonics and Sub-harmonics

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...

## Star Delta Starter and Its Working Principle

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...

## Power Angle Curve of Synchronous Machine

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...

## Load Angle or Power Angle and It’s Significance

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...

## Power Flow Equation through an Inductive Load

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...