The synchronization process. Discuss how the alternator shares a load with an infinite bus or supplies it alone as an isolated load
The synchronization process:
Synchronization is the process of
matching the speed and frequency of a generator or other source to a running
network. An AC generator cannot deliver power to an electrical grid unless it
is running at the same frequency as the
network. If two segments of a grid are disconnected, they cannot exchange AC
power again until they are brought back into exact synchronization.
Infinite bus:
The bus whose voltage and frequency remains constant even
after the variation in the load is known as the infinite bus. The alternators
operating in parallel in a power system is the example of the infinite bus. The
on and off of any of the alternator will not affect the working of the power
system.
How the alternator shares a load with an infinite bus
or supplies it alone as an isolated load?
We should think of exchanging a load on
an infinite bus. For output, the alternators will also have to be linked in
parallel while the AC power systems are interconnected. The generating stations
would have more than two alternators working in parallel.
Condition for
Parallel Operation of Alternator:
Here are certain requirements for simultaneous alternator
operation to be met. Before we move into that, we will grasp those words that
are as follows:
• The mechanism of linking two alternators or
an alternator to an endless parallel bus bar network is regarded as
synchronization.
• Working machine is load bearing unit.
• Incoming unit is the alternator or pump
that needs to be attached to the network in parallel.
The conditions to be satisfied are:
1. The phase sequence of the incoming machine voltage and the bus bar voltage should be identical.
2. The RMS line voltage (terminal voltage) of the bus bar or
already running machine and the incoming machine should be the same.
3. The phase angle of the two systems should be equal.
4. The frequency of the two terminal voltages (incoming
machine and the bus bar) should be nearly the same. Large power transients will
occur when frequencies are not nearly equal.
General
Procedure for Paralleling Alternators:
The
diagram below indicates an alternator (generator 2) that is parallel to a power
plant operating (generator 1). To supply power to a load, these two devices are
about to synchronise. Generator 2 is going to follow, use a turn, S1. This turn
will never be shut down without following the criteria laid out above.
1. About equivalent terminal voltages. This can be achieved
by modifying incoming computer terminal voltage by increasing field current and
having it equivalent to operating device line voltage using voltmeters.
2. The step series of the devices is
verified by two methods. They are the following
·
Application of
a Synchroscope first. The phase series is not explicitly tested but is used to
calculate the disparity in phase angles.
·
2. Next, we need to test and validate the amount of incoming
and operating processes. It will be basically the same. The level of dimming
and brightening of lamps may be checked to do so.
3. The two voltages (incoming alternator and operating
system) can slowly alter the process until the frequencies are approximately
identical. These modifications can be detected, and when the phase angles are
identical, the turn, S1, can be closed.
(Abstract )
The synchronization process, Infinite bus: The bus whose voltage and frequency remains constant, there are four Conditions for Parallel Operation of Alternator, General Procedure for Paralleling Alternators, make the terminal voltages equal, There are two methods to check the phase sequence of the machines( Synchroscope and three lamp method)
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