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generator manual syncronizer or synchroscope

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smorc

Electrical
Jun 4, 2002
2
Can i have ur inputs with regards to synchronizing of generators using manual synchroscope..Below are the details of the design;

1. There is an existing generator engine rolls royce 203.81 kva, 420/277 volts step-up to 13.2 kv connected to the transmission line. Note that the existing gensets has no built in synchronizer.
2. There two brand new units 200 kva generators 240 volts step-up to 13.2 kv which will installed beside the existing genset and it will be connected to same transmission line.
3. We are planning to synchronized the three gensets.
4. We prefer to install a manual syncronizer since this will be installed in far flung barangay.

Hope u can help came out with a detailed design of the above scenario...tks in advance


 
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To manually synchronize, the operator needs to know the frequencies and voltages of the two systems, as well as the relative phase angle between them. In addition he (or she) needs to be able to adjust the generator voltage as well as engine speed.

The synchroscope takes single phase potentials from the two systems to be synchronized - its rotation is proportional to the frequency difference and its position is equal to the phase angle difference. This is often supplemented by indicating lights that are receive a voltage equal to the voltage difference between the two systems.

Normally only one synchroscope is used and synchronizing switches are provided for each line that will need to be synchronized. The synch switches have ONE removeable handle to prevent unintentional parallel connection of potential tranformers.

I would advise that you provide a synch-check relay to supervise the manual closing to prevent gross operator error.
 
It is doubtful finding “detailed design” information on the ‘net, but there is potentially applicable text at:
Experiment #5
Before synchronizing, the frequency of the two areas must be matched. Adjustments are made by the area most able to do so (preferably the smaller area). The aim of the other area is to maintain its frequency at a stable point. Voltage of the two areas are as close as possible. Ideally, the smaller area adjusts frequency and voltage to that of the larger area. When using a synchroscope, frequencies are such that the scope is moving slowly in the fast direction, or with three lights, all lights are out. Failure to match frequency and voltage between the two areas can result in significant equipment damage and possible shut-down of one or both areas.
When paralleling two systems (i.e., re-synchronizing islands) frequency must be matched, and the synchroscope should be rotating no faster than one revolution every thirty seconds. Voltage should be matched as closely as possible, however a voltage difference of up to ten percent is allowable.
 
How to ensure that the phase sequence of the two sources also is matching?
Secondly, I have noticed that most of the synchronization check relays use only two lines of each source for comparison. What if the line-to-line voltages vis-a-vis the third line do not match?
 
The phase sequence is generally tested during commissioning. Once the correct phase sequence has been established, it is not necessary to verify this every time the generator is synchronized.

The synchronizing system (auto or manual) generally compares only one phase of each system to be synchronized. So it is important to do a phasing check prior to initial operation of the generator.
 
How do you Synchronize the existing Genset right now? Are the new Units designed to be Synchronized to the Utility or Grid?
 
Suggestion to the previous posting: Existing Gensets are supposed to meet the local Utility or Grid owner requirements that impose interfacing conditions on the existing gensets.
 
jbartos,
I am not sure I understand your posting. Are you telling me what I should assume about smorc's application in far flung barangay. I have worked all over the world on Plant Plants and have found just about every possible interface. Smorc mentioned that the existing Genset had no built in synchronizer. Does that mean no automatic or does it mean that they run islanded at this time and feed a transmission line to a connected load? If the first Genset is stand alone, feeding a load, and now they want to add additional Gensets in parallel then it changes the design. I don't think we should be assuming anything.
 
Suggestion/comment to the previous posting: They "... are planning to synchronized the three gensets.
4. We prefer to install a manual syncronizer since this will be installed in far flung barangay."
Apparently, they are creating some regulation on the existing and improved power generation, and on the associated grid.
 
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