Control and power supply system for helicopter turbine engines

An electrical control and power supply system for at least one helicopter motor/generator, the system comprising:

• a first DC/AC converter selectively delivering AC electrical power to the at least one helicopter motor/generator, depending on respective positions of contactors of a connection matrix actuated from an electronic control circuit, the first DC/AC converter powered with DC by a DC power supply device that includes either a circuit rectifying an AC voltage delivered via a first contactor by a starter/generator of an auxiliary power unit (APU), or a voltage booster DC/DC converter powered from a battery via a second contactor and formed by connecting in series a three-phase inductor and a second DC/AC converter via at least one contactor of the connection matrix,
• wherein, for injecting additional power to the at least one helicopter motor/generator once started from said starter/generator of the APU, the connection matrix further a contactor for connecting the first DC/AC converter in parallel with the second DC/AC converter.