Hi,
Does anyone know how to build a Synchroscope?
In AC electrical power systems, a synchroscope is a device that indicates the degree to which two systems (generators or power networks) are synchronized with each other.
This will be nice to link my 2 power stations up together or two generators
Does anyone know how to build a Synchroscope?
In AC electrical power systems, a synchroscope is a device that indicates the degree to which two systems (generators or power networks) are synchronized with each other.
This will be nice to link my 2 power stations up together or two generators
Yeah, you'll need cross current compensation, something to deal with output voltage fluctuations, and something to maintain synchronous operation all the time.
You can use an oscilloscope to see what they look like in comparison to each other; but you need something a lot more sophisticated to maintain a phase relationship.
Either of the generators will have a somewhat differing frequency and voltage output and this will cause something to blow up or break down if you just connect them together.
I can't tell you exactly what you need to make them stay in sync with each other and balance the loading but I can tell you that this doesn't sound like a good idea given the style of generators you're likely to have.
You can use an oscilloscope to see what they look like in comparison to each other; but you need something a lot more sophisticated to maintain a phase relationship.
Either of the generators will have a somewhat differing frequency and voltage output and this will cause something to blow up or break down if you just connect them together.
I can't tell you exactly what you need to make them stay in sync with each other and balance the loading but I can tell you that this doesn't sound like a good idea given the style of generators you're likely to have.
While I was enlisted in the Army, I worked on a plant of four old Russian 150kVA AC generators. Their synchronization was very simple. There was one signal bulb, which was connected between 2 phases of two generators. The bulb was flashing or lit up when the generators were out of phase. My job was to change the frequency and output voltage of one generator until the flashing/light of the bulb started to slow down or eventually stopped. When that happened (i.e. when the generators were in sync), I would connect the generators in parallel.
When the first generator was loaded, the second generator would not start taking the load off the first one until its output voltage was increased a bit. Individual loads of each generator were regulated by fine-tuning their output voltages.
Regards,
Milan
When the first generator was loaded, the second generator would not start taking the load off the first one until its output voltage was increased a bit. Individual loads of each generator were regulated by fine-tuning their output voltages.
Regards,
Milan
Duo,
I concur with moamps. A good friend of mine, Ham radio operator and Senior Field Technician for Detroit Edison once told me how they synch multiple generators. Atthe power station, they get their peakers (BIG trailer-mounted 10MW Generators added to the grid for the summer) synch'ed to within 5-10 degrees of the main generators at the plant, then throw the switch. The result: the units (physically) snap into synch, and stay that way until one or more units run out of fuel, which has never happened.
The lesson here, complex synchronization schemes are not necessary due to the nature of how the different machines interact with each other.
Hope this helps.
Kind regards,
Steve
I concur with moamps. A good friend of mine, Ham radio operator and Senior Field Technician for Detroit Edison once told me how they synch multiple generators. Atthe power station, they get their peakers (BIG trailer-mounted 10MW Generators added to the grid for the summer) synch'ed to within 5-10 degrees of the main generators at the plant, then throw the switch. The result: the units (physically) snap into synch, and stay that way until one or more units run out of fuel, which has never happened.
The lesson here, complex synchronization schemes are not necessary due to the nature of how the different machines interact with each other.
Hope this helps.
Kind regards,
Steve
Duo,
Yep. I caught it. Are you good in QRZ?
Andrew, This might not be the most sophistocated method, but place a lightbulb between each phase of the add-on unit, and the line(s) of the existing microgrid. Start 'er up, and adjust engine speed until the (three) lightbulbs go out, or nearly so. THen throw the switch, and the aforementioned self-synchronizing will take place.
Steve
Yep. I caught it. Are you good in QRZ?
Andrew, This might not be the most sophistocated method, but place a lightbulb between each phase of the add-on unit, and the line(s) of the existing microgrid. Start 'er up, and adjust engine speed until the (three) lightbulbs go out, or nearly so. THen throw the switch, and the aforementioned self-synchronizing will take place.
Steve
go to www.QRZ.com and type in your call sign, VA3MSN, in the space at the top of the page and see what happens................ 
"I'm good in it" means: Is your info in qrz good, or outdated? I can't believe they actually want $ to update their database, especially since I never requested my info be put in there. I guess they just go to the FCC and see who has a new license and automatically put them in there. As a result, my info is old, and I need to update the pic. UGH!
"I'm good in it" means: Is your info in qrz good, or outdated? I can't believe they actually want $ to update their database, especially since I never requested my info be put in there. I guess they just go to the FCC and see who has a new license and automatically put them in there. As a result, my info is old, and I need to update the pic. UGH!
The light bulb idea is a good idea, and has been done for years. Highly recommend taking each generator signal through an isolation transformer before feeding the light bulb, however. Doesn't have to be big. Once you verify phase sequence, you only need to synch on one phase, not all three.
With regards to keeping generators in synch, it's not quite that simple.
The typical cogeneration site synchronizes their generator to the utility by controlling the speed of an electronic governor. The engine's mechanical speed controls the frequency of output, so you need (or should) have some means of controlling the speed prior to synchronizing. Once this is done, and the breaker closes, the generator's synchronous speed is controlled by the utility frequency, because it is impossible for them to operate at different speeds (without a fault condition). The utility is the controlling factor, because it is so much larger than the piddly generator.
If you are trying to parallel two generators, this condition does not exist, since you are no longer paralleling to an infinite bus. You need to have a master/slave system going on, where one generator controls the synchronous speed. Without it, the gens will oscillate. Do an internet search on DROOP and ISOCHRONOUS.
Further, once a generator is paralleled to the utility (or another generator), you need to control kW output by controlling the fuel input to the engine. If this control is not correct, you will either overload the little gen, or turn your generator into a motor. Most voltage regulators on stand alone generators are incapable of paralleling, as they only look at output voltage.
There is not some simple answer like "yeah, it will just work". You need to know exactly what equipment you have to work with, and ensure you are set up to parallel.
With regards to keeping generators in synch, it's not quite that simple.
The typical cogeneration site synchronizes their generator to the utility by controlling the speed of an electronic governor. The engine's mechanical speed controls the frequency of output, so you need (or should) have some means of controlling the speed prior to synchronizing. Once this is done, and the breaker closes, the generator's synchronous speed is controlled by the utility frequency, because it is impossible for them to operate at different speeds (without a fault condition). The utility is the controlling factor, because it is so much larger than the piddly generator.
If you are trying to parallel two generators, this condition does not exist, since you are no longer paralleling to an infinite bus. You need to have a master/slave system going on, where one generator controls the synchronous speed. Without it, the gens will oscillate. Do an internet search on DROOP and ISOCHRONOUS.
Further, once a generator is paralleled to the utility (or another generator), you need to control kW output by controlling the fuel input to the engine. If this control is not correct, you will either overload the little gen, or turn your generator into a motor. Most voltage regulators on stand alone generators are incapable of paralleling, as they only look at output voltage.
There is not some simple answer like "yeah, it will just work". You need to know exactly what equipment you have to work with, and ensure you are set up to parallel.
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.