Surge Protective Devices for EV Charging Stations, DC Loads
06/04/2021 2:15 AM
I work for a company for installing EV Fast chargers (internship)
Current scenario - we are planning to install 100kW EV chargers in a gas Station / Petrol Bunks / CNG Stations in India.
We are tapping 100kW supply from a Utility Transformer.
The transformer is at distance of 100meters from the location.
It has Lightning arrestors on the top of the pole.
From the transformer it comes to a utility metering Panel which is controlled by the utility.
From there it goes to a Main Station Panel.
From the Station Panel to goes to the Charger Distribution panel in which AC to DC conversion happens- 100kW.
From the charger Distribution panel it goes to the individual charging guns of 15kW DC.
Lightning Risk assessment done and it was deduced a SPD would be needed. (not done by me).
The station panel is located at 20 meters from the charger panel.
The charging gun is location at distance of 15m from the charger panel.
Now the Questions:
Type -1 SPD considered for the station Panel, is this okay?
Type-2 SPD considered in the Charger Panel because of the distance between charger panel and the Station panel. is this okay?
Type-3 SPD not considered at the Charging gun even though it is 15 meters away from the Charger Panel. the reason being, the charging gun is DC and is Electrically separated from the charger Panel by means of Rectifiers. Is this okay to not provide a SPD for the Guns? if not okay, any logical explanation would be helpful