Abstract: An electrical apparatus, including: a circuit breaker having a breaking capacity and a breaking current; a DC voltage source including two batteries connected in parallel, connected in series with the circuit breaker, the sum of short-circuit currents of the batteries being greater than the breaking capacity, each battery including: a first branch including storage batteries and a switch connected in series; a second branch connected in parallel with the first branch and including a free-wheeling diode; an ammeter measuring output current; and a control circuit configured to detect a short-circuit. The control circuits simultaneously keep a majority of switches open and close one switch to apply a current passing through the circuit breaker which is higher than the breaking current and lower than the breaking capacity.

Abstract: An underwater vehicle includes an on board power grid, the power grid including powerlines, a plurality of DC energy storage sources based on lithium-ion batteries, each source having a positive terminal and a negative terminal, and being connected on the one hand to a charger and on the other hand to energy consumers of the vehicle, one of the terminals of each source being connected to a first powerline of the power grid, the other terminal of each source being connected on the one hand by a second powerline of the power grid to the charger through one-way semiconductor conducting unit and on the other hand by a third powerline of the electric grid to consumers through one-way semiconductor conducting unit.

Abstract: An electrical apparatus, including: a circuit breaker having a breaking capacity and a breaking current; a DC voltage source including two batteries connected in parallel, connected in series with the circuit breaker, the sum of short-circuit currents of the batteries being greater than the breaking capacity, each battery including: a first branch including storage batteries and a switch connected in series; a second branch connected in parallel with the first branch and including a free-wheeling diode; an ammeter measuring output current; and a control circuit configured to detect a short-circuit. The control circuits simultaneously keep a majority of switches open and close one switch to apply a current passing through the circuit breaker which is higher than the breaking current and lower than the breaking capacity.