Protecting a power supply including a plurality of batteries in parallel against an external short-circuit

An electrical installation, comprising:

• a circuit-breaker having a breaking capacity and a tripping current;
• and
• a DC voltage source comprising at least two electrochemical accumulator batteries connected in parallel, the voltage source being connected in series with the circuit-breaker;
• wherein the sum of short-circuit currents of the batteries connected in parallel is higher than the breaking capacity of the circuit-breaker, each of the batteries including:
• a first arm including the electrochemical accumulators of the battery and a switch, which accumulators and switch are connected in series;
• a second arm connected in parallel with the first arm and including a flyback diode;
• an ammeter measuring current delivered by this battery;
• and
• a control circuit configured to detect a short-circuit when the current delivered by a battery is higher than a threshold;
• the control circuits configured, after a short-circuit has been detected, to simultaneously keep at least most of the switches open and to close at least one of the switches to apply a current passing through the circuit-breaker higher than the tripping current and lower than its breaking capacity.