Sweden – grid protection settings according to EIFS 2018:2

In Sweden, battery energy systems up to 1.5 MW are classified as Type A installations.

Type A systems - protection settings

For Type A systems, install a grid monitoring relay and configure it with the protection settings shown below:

Protection settings for Sweden Type A

Relay protection setting	Time	Level
Overvoltage - step 2	60 s	1.1 x Un
Overvoltage - step 1	0.2 s	1.15 x Un
Undervoltage	0.2 s	0.85 x Un
Overfrequency	0.5 s	51.5 Hz
Underfrequency	0.5 s	47.5 Hz
ROCOF Short for "Rate of Change of Frequency". In grid monitoring relays, it refers to how quickly the electrical frequency is changing over time. It's used to detect unstable grid conditions - especially during events like load shedding or generator disconnection - and can trigger protective actions if the frequency changes too rapidly.	0.5 s	2.5 Hz/s

Automatic reconnection settings for type A

Configure the relay to allow automatic reconnection based on frequency only when the mains frequency has remained continuously within the range of 47.5 Hz to 50.1 Hz for a minimum of 180 seconds.

In addition, configure voltage-based automatic reconnection so that it is only permitted when the grid voltage has remained within the range of 207 V to 253 V for at least 180 seconds.