Arc fault detection for battery packs in energy generation systems

An energy generation system, comprising:

• a photovoltaic (PV) array for generating direct current (DC) power;
• an inverter coupled to the PV array, wherein the inverter is configured to receive the generated DC power from the PV array and to convert the DC power to alternating current (AC) power;
• and
• a battery pack coupled to the inverter and configured to store and discharge energy;
• wherein the battery pack comprises:
• a cell array of conductively interconnected power cells;
• a DC-to-DC converter coupled to the cell array to receive power from the cell array during discharging of the cell array or output power to the cell array during charging of the cell array;
• a pair of output terminals coupled to the DC-to-DC converter for coupling with an external device;
• and
• an arc fault detection system coupled between the DC-to-DC converter and the pair of output terminals, wherein the arc fault detection system comprises:
• a first sensor for measuring power transmitted between the DC-to-DC converter and the pair of output terminals;
• and
• a controller coupled to the first sensor and configured to enable or disable the battery pack based on a measurement of the power transmitted between the DC-to-DC converter an the pair of output terminals.

A method of determining an arc fault in a battery pack for an energy generation system, the method comprising:

• measuring, by a first sensor disposed between a cell array and a direct current (DC)-to-DC converter in the battery pack, power provided between the cell array and the DC-to-DC converter;
• measuring, by a second sensor disposed between the DC-to-DC converter and the a of output terminals for the battery pack, power provided between the DC-to-DC converter and the set of output terminals;
• determining, by a controller coupled to the first and second sets of sensors, that an electrical arcing has occurred based on the measurements from the first set of sensors and the second set of sensors;
• and
• performing, by the controller, at least one of:
• disabling, by a cell battery management system (BMS) coupled to and controlled by the controller, the cell array when arcing is detected by the first sensor and the second sensor during battery discharging,
• disabling, by a converter BMS coupled to and controlled by the controller, the DC-to-DC converter when arcing is detected by the second sensor but not detected by the first sensor during battery discharging, and
• disabling, by the converter BMS, the DC-to-DC converter when arcing is detected by the first sensor but not detected by the second sensor during battery charging.