Power supply system for a load and electric power plant including such a system

The system (20) has a converter (48) whose input is connected to a power source (14) and output is connected to a load i.e. auxiliary equipment (22). A circulation bus (16) circulates electric current and includes two ends (33, 34). An injection device (50) injects additional alternating voltage at one of the ends of the bus. The injection device is connected to the end. A recovery device (52) recovers the additional injected alternating voltage, and is connected between the other end of the bus and the load so as to supply the load with electrical current. An independent claim is also included for an electrical energy production plant.