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smruti
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in a parallel operation of synchronous generators...while synchronising a new generator to a bus..why the speed of incoming generator should be slightly more than the other generators that are connected to the bus?
how it will cause phase difference when the speed will be same? can you please elaborate?Rippetherocker said:Because as soon as the generator is connected it will take some load and will try to slow down and the already loaded gen. will try to speed up. If both had the same intial speed this will result in a phase difference after connection. A reverse current will flow into the new gen. and activate the reverse power trip.
thank you..FOIWATER said:The speed will not be the same. When the generator is connected it will provide power to the system and the electrical counter torque on the shaft won't match the input mechanical torque. The machine will slow down. The other machine will speed up, since it takes less load now. With them running at different speeds they will be out of synch. That causes the phase difference. I didn't really add anything to the first response but I think he is pretty clear. Does it make sense?
A synchronous generator, also known as an alternator, is a device that converts mechanical energy into electrical energy. It works by using a rotating magnetic field to induce an alternating current in the stator windings.
Incoming speed refers to the rotational speed of the generator's rotor, which is typically controlled by a prime mover such as a gas turbine or steam turbine. This speed determines the frequency of the generated electrical output.
The connected speed of generators refers to the speed at which they are synchronized and connected to the power grid. If the connected speed is greater than the incoming speed, the generator will act as a motor and consume mechanical energy to maintain the required speed. If the connected speed is lower, the generator will act as a generator and produce electrical energy.
If the incoming speed is higher than the connected speed, the synchronous generator will accelerate and generate excess electrical energy. This can cause instability in the power grid and may lead to a blackout if not properly controlled.
Synchronization is achieved by adjusting the speed of the incoming synchronous generator to match the connected speed of the connected generators. This is typically done using specialized control systems that monitor and adjust the speed of the rotor to maintain synchronization. Once synchronization is achieved, the generators can be connected to the power grid without causing any disturbances.