This depends on the properties of the grid in the connection point and depends on he duration of a disturbance. In Sweden, were I live, it is Svenska Kraftnät who stipulates the disconnection limits for medium and high voltage connections. For voltages below 10 kV, it is local grid owners responsibility but generally the microgeneration standard settings are ok. For a 400 V (line-to-line) 230 V (line-to-neutral) connection via trafo to an 11 kV Swedish grid, according to Svenska Kraftnät, the limits may as an example be:
Function: setting (time)
Overfrequency: 52 Hz (0,5 s)
Underfrequency: 47,5 Hz (0,5 s)
Undervoltage: 207 V (-10 %) (60 s)
Undervoltage: 195,5 V (-15 %) (3 s)
Overvoltage: 253 V (+10 %) (60 s)
Overvoltage: 264,5 V (+15 %) (3 s)
So, depending on the size of the disturbance, the disconnection setting varies. Hope this answer adds any useful information!
Normally the fluctuation of solar irradiation donot lead to voltage unstable but slightely change.
In China, the standard doesnt propose specially limit for solar plant or other renewabl energy plants. But the voltage is asked under limit after solar plant connected to grid.
According to EN 50160 +/- 10% of nominal voltage is allowed during 10 minutes intervalls over a whole year. -15% are sometimes allowed.
Fast changes I am not sure at the moment.
In Germany it exist a recommondation of grid codes for low voltage grids: VDE AR N 4105.
Here it is a limitation of voltage rise by 3% related to the voltage in the grid without PV.
The PV array side of a PV system produces dc voltage. The only condition is to ensure that the inverter matches very well with the minimum and maximum voltages that the PV array produces under normal operating conditions. The inverter itself converts (changes) dc to ac and synchronizes the output ac voltage to the grid. The inverter itself has specific settings that are either pre-programmed in it or can be changed by authorised personnel to match the local/regional or national grid regulations. Hence to answer your question, you need to look at the electricity network code of that particular country/region or state and set/check your inverter settings accordingly.
- Badges
- Science topic