How A Prime Movers Works In An Electic Power Plant

Electrical Power Plant today is more important than any other, that is because without those power plant operate we cannot do anything. From manufacturing plant, because we are all depend on Electricity. So therefore it a high time to know from the very beginning what is a prime movers, how it works or what is
all about.  To get the plant started, prime movers are typically Diesel Engines, Gas or Steam Turbines, or  Hydro and Wind Turbines. This Prime movers converts oil, gas, coal, wood, uranium, water, wind, etc. into mechanical energy. The mechanical energy is supplied to the shaft  of the generator and the generator in turn transform this mechanical energy to electrical energy. High quality electric power generating systems deliver precise voltage and frequency. The voltage regulator as noted earlier, provides the precise voltage regulation. The prime mover GOVERNOR, by accurately  controlling the speed, provides the precise frequency regulation.

What is a Governor?
Govers Define as a device which controls the speed or power of a prime mover in order to convert the power to useful work.When the governor senses the speed of a prime mover and controls the prime mover to maintain its speed (or load) at a desired output.Like for example if  you drive a car. You function as a governor when you control the car’s speed under a varying driving conditions. The driver adjust the accelerator that controls the fuel to maintain the desired speed at a certain level and adjust from time to time should the desired speed varies. Acutually the original  governors were entirely mechanical like a pair of centrifugal flyweights in most ballheads. It is known for its ruggedness, usefulness and sensitivity. The
flyweights are rotated by a drive from the prime mover that is directly related to the speed. As the speed changes, the flyweights move out at the top due to  centrifugal force. The centrifugal action causes the weights to increase the force on the thruster that control the pilot valve thereby changing the speed of  the prime mover due to applying or removing load.

What a Governor Does?
As the prime mover gets started or a speed of about 25%, a governor mechanism “comes to life”. The governor senses the prime mover rotation and begins to  regulate the linkages controlling the fuel/steam supply of the prime mover.But if the prime mover tends to increase speed above the set speed of the  governor, the governor mechanism decreases the controlling lever opening of the fuel/steam supply of the prime mover.Eventually, the prime mover speed will  be controlled so that only enough fuel/steam is being admitted, (power in) to hold the prime mover approximately the speed setting of the governor.

What Happens as Load is Added to the System?
As the customer load demand increases, the generator must supply the load instantaneously. The generator slows down as more power is being taken out from the  generator than what is being produced. But as soon as the shaft slows down, the governor mechanism senses and causes to increase the fuel/steam rack opening  it and increasing fuel/steam supply of the prime mover.The power produced by the prime mover will increase to match the generator demand. As the speed will  be a little less than before, since if the speed recover completely, the governor mechanism senses and causes to increase the fuel rack opening increasing
power for the prime mover. Therefore, the frequency of the AC produced by the generator will get lower as the generator slows down and load increases. What is a Governor Speed Setting Does? The speeder spring is the part that sets the “desired speed”. Applying more force down on the speeder spring causes the governor to increase fuel/steam supply to the prime mover. This initial force is usually set by the operator for the  desired or “reference’ speed. It can be set by an adjusting screw, a knob, a lever, a DC electric motor, an air pressure, or solenoids, depending on the  specific governor.

How to Adjust the Governor Setting?To Keep frequency constanct, need to operate governor speed setting mechanism to reaise the no-load speed setting, compensating for the droop in speed with
load