Synchronizing of Photovoltaic power station
Synchronizing of Photovoltaic power station
(OP)
For current project I have to solve a problem which I never faced before:
Project is for substation 20/110 kV for large (50 to 150 MW) photovoltaic power station. My problem is how such substation have to be coupled to the grid. If generators are conventional rotating machines it is clear. But for PhV technology I suppose it should be different.
I wonder should I provide decoupling of the station in case of low frequency in power grid.
How feeders are synchronized with the grid, and on what level - 20 kV feeders(leading to inverter modules) or 110 kv connection with the grid?
Project is still on conceptual stage, main contractor have not choosen supplier of inverters, so I have no anybody to ask regarding the way of connection.
As you understand I have no any experience with PhV technology and will be gratefull for any help.
Project is for substation 20/110 kV for large (50 to 150 MW) photovoltaic power station. My problem is how such substation have to be coupled to the grid. If generators are conventional rotating machines it is clear. But for PhV technology I suppose it should be different.
I wonder should I provide decoupling of the station in case of low frequency in power grid.
How feeders are synchronized with the grid, and on what level - 20 kV feeders(leading to inverter modules) or 110 kv connection with the grid?
Project is still on conceptual stage, main contractor have not choosen supplier of inverters, so I have no anybody to ask regarding the way of connection.
As you understand I have no any experience with PhV technology and will be gratefull for any help.
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It may be like this in theory and practice, but in real life it is completely different.
The favourite sentence of my army sergeant






RE: Synchronizing of Photovoltaic power station
Why would you want to disconnect on low frequency?
1. low frequency could indicate an island, so a very low frequency might be worth while, provided the voltage is high or low.
2. You have no parts that maybe damaged by a low frequency, like a resonit frequency in a turben.
Also consiter the short circuit operation of the PV system, where most inverters my only put out 1.1 to 1.5 PU into a fault, or some may shut down.
And some countries may have a short circuit ride through requirment.
RE: Synchronizing of Photovoltaic power station
I don't worry about damage of inverters from low system frequency, but I wonder how they will react if system frequency start decreasing. Probably they will shut down from their own control system ?
Interesting case for me is decoupling in case of short circuit on 110 kV line. Relay protections should trip 110 kV circuit breaker, but should this trip shut down inverters too ? Accordinh to me they should be switched-off, because I cannot imagine control system which will synchronize 50 or more inverters in the same time for reclosing of the line.
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It may be like this in theory and practice, but in real life it is completely different.
The favourite sentence of my army sergeant
RE: Synchronizing of Photovoltaic power station
I don't worry about damage of inverters from low system frequency, but I wonder how they will react if system frequency start decreasing. Probably they will shut down from their own control system ?
Interesting case for me is decoupling in case of short circuit on 110 kV line. Relay protections should trip 110 kV circuit breaker, but should this trip shut down inverters too ? According to me they should be switched-off, because I cannot imagine control system which will synchronize 50 or more inverters in the same time for reclosing of the line.
The same question is valid for short circuit on 20 kV feeders - in such case all inverters connected to the feeder should be switched-off too ?
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It may be like this in theory and practice, but in real life it is completely different.
The favourite sentence of my army sergeant
RE: Synchronizing of Photovoltaic power station
RE: Synchronizing of Photovoltaic power station
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It may be like this in theory and practice, but in real life it is completely different.
The favourite sentence of my army sergeant
RE: Synchronizing of Photovoltaic power station
I think your specific questions about the inverters would be best answered by the manufacturer. The inverters probably won't ever be exposed to excessively low frequencies unless the utility has some major problems of their own. You could expect 60Hz (or 50...) with a +/- range of no more than 1Hz or zero.
RE: Synchronizing of Photovoltaic power station
You might check the utility for short circuit ride through. We require, or the power pool, require this, due to the concerns of loseing significent generation, and destablizing the grid.
RE: Synchronizing of Photovoltaic power station
RE: Synchronizing of Photovoltaic power station
My name is Plamen.
Just send me an empty e-mail and I will send you more information about the case.
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It may be like this in theory and practice, but in real life it is completely different.
The favourite sentence of my army sergeant