What does CV stand for in exercise?
What is the critical speed of turbine?
In a broader sense, critical speed is also known as the rotational speed at which the frequency of a pulsating torque coincides with the natural torsional frequency of the shaft assembly.
What is the critical speed of a generator?
The critical speed is the maximum resistance of the circuit in which the shunt generator resistance become the critical field and produce the voltage when the critical filed of the resistance is high as compared to the field circuit resistance.
How do you find the critical resistance of a DC generator?
After drawing OCC curve, Then tangent is drawn to its initial portion. The slope of the curve gives the critical resistance. The value of the resistance represented by the tangent to the curve is known as critical resistance for a given speed.
What is voltage regulation in DC generator?
In the ideal case, VR will equal 0%. In order to achieve this, the excitation voltage must be adjusted with load conditions, i.e. the field voltage must be controlled.
What regulates voltage in a generator?
The stator winding of this alternator puts out an AC current/voltage to a voltage regulator. The voltage regulator turns that AC input into a DC output which is controlled so as to ultimately control the current into the main generator field.
What is voltage regulation in generator?
The Voltage Regulation of a Synchronous Generator is the rise in voltage at the terminals when the load is reduced from full load rated value to zero, speed and field current remaining constant. It depends upon the power factor of the load.
What is voltage regulation formula?
So for example, if a single-phase transformer has an open-circuit no-load terminal voltage of 100 volts and the same terminal voltage drops to 95 volts on the application of a connected load, the transformers voltage regulation would therefore be 0.05 or 5%, ((100 – 95)/100)*100%).
Which voltage regulation is best?
But, the voltage regulation will vary as power factor varies. Ideally, there should be no change in the transformer’s output voltage from no-load to full-load. In such a case, we say the voltage regulation is 0%. To get the best performance out of your transformer, you need the lowest possible voltage regulation.
What is full load voltage?
The terminal voltage when full load current is drawn is called full load voltage (VFL). The no load voltage is the terminal voltage when zero current is drawn from the supply, that is, the open circuit terminal voltage. Some portion of voltage drops down due to internal resistance of voltage source.
What is voltage regulation of Zener diode?
A zener diode is always operated in its reverse biased condition. As such a simple voltage regulator circuit can be designed using a zener diode to maintain a constant DC output voltage across the load in spite of variations in the input voltage or changes in the load current.
What are zener diodes used for?
Zener diodes are used for voltage regulation, as reference elements, surge suppressors, and in switching applications and clipper circuits. The load voltage equals breakdown voltage VZ of the diode. The series resistor limits the current through the diode and drops the excess voltage when the diode is conducting.
Why is zener diode reverse biased?
A reverse biased ,zener diode exhibits controlled the breakdown & allows current to keep voltage across zener diode close to the zener breakdown voltage.