Hi friend
My Project topic is DETECTING POWER GRID SYNCHRONIZATION FAILURE ON VOLTAGE OR FREQUENCY
Please help me about this????????????
Application?????
Future scope?
advantage?????????
disadvantages?
conclusion??????????????
[/size][/font]
Posts: 14,118
Threads: 61
Joined: Oct 2014
Synchronization means minimizing the voltage, frequency and phase angle difference between the corresponding phases of the generator output and the mains supply. An AC generator must be synchronized with the mains before the connection. It can not deliver power unless it is operating at the same frequency as the network. Synchronization must occur before connecting the generator to a grid. Synchronization can be performed manually or automatically. The purpose of synchronization is to monitor, access, enable and automatically take control action to prevent voltage and frequency abnormalities.
The rules for synchronization must be followed:
Voltage Fluctuation:
When a generator is synchronized with a power grid, there is usually a voltage fluctuation in the distribution line. During synchronization, the voltage fluctuation should not exceed 3% at the common coupling point.
Sync Limits:
Limits that allow synchronization are
Phase angle +/- 20 degrees
Maximum voltage difference - 7%
Maximum slip frequency - 0.44%
Relays:
To check the synchronization, use "synchronization check relay". The use of relays can not be applied to induction generators. The use of the synchronization check relay is to accept as backup during synchronization and to ensure that a generator does not connect to a dead distribution line.
Synchronization of induction generators:
For the synchronization of the induction generators only has to be run up to the sync speed and connected. This will use standard motor controllers. To power the generators to the synchronization speed, the power of the turbine shaft will be used. The speed of the motors depends on the frequency supplied and the number of poles on the generators.
Synchronization of synchronous machines:
For synchronous generators, the output waveform must be in phase with the network voltage waveform or specified limits. The phase angle change rate between the mains and the machine (generator) must be within the specified limits.
Some other rules are the arrangement of the variable speed drive to maintain a constant output frequency, the protection between the connections between the generator and the distribution system.
Sync Error:
The synchronization circuit may fail to respond to an input pulse received when the received input pulse is short-circuited than the synchronizer sampling period. Then no synchronized representation will take place. When the pulse rate of the input signal is greater than the sync speed of the synchronizer, then it may also fail to respond. Sometimes the synchronizer can fail if it ignores input events. These are all circumstances that could create problems if not detected. There are several reasons for the failure of the synchronization of the electrical network.
