Method for controlling a charging device on board an electric or hybrid vehicle

1. A method for controlling a battery-charging device for a motor vehicle, the charging device comprising a rectifier stage performing a power factor correction function, including three phase connections able to be connected at the input of a single-phase or three-phase electrical power supply grid each by a serial inductance coil, and a DC-DC converter stage connected between the rectifier stage and a battery, the rectifier stage being a three-phase Vienna rectifier comprising a three-phase diode bridge and three switching arms integrated into the diode bridge, each switching arm comprising a serial assembly of a high switch able to be controlled when the current of the grid is positive and a low switch able to be controlled when the current of the grid is negative, the switching arms being interconnected at a midpoint to which a first and second bus capacitor are connected at the output of the rectifier stag, the DC-DC converter stage comprising first and second LLC resonant converters connected at the input respectively to the first and second power supply bus capacitors by first and second power supply buses and, at the output, to the battery,

the method being of the type according to which the current is regulated at the input of the charging device using the three-phase Vienna rectifier, each switching arm being controlled using pulse width modulation control signals, the switching duty factor of which is determined based on the regulation of the input current,

the method comprising powering the charging device by a single phase and regulating the voltage of the first and second power supply buses independently using the first and second LLC resonant converters so as to provide a fixed regulated voltage on each of the power supply buses.

2. The method according to claim 1 , wherein, in a first single-phase connecting mode corresponding to a first single-phase charging power level from among three charging power levels from low to high, first and second of the three-phase connections of the charging device are respectively connected to a phase and neutral wire of the single-phase electric grid, the second phase connection being connected to the neutral wire by a connection relay.

3. The method according to claim 2 , wherein the switches of the switching arm corresponding to the second phase connection of the charging device connected to the neutral wire are kept in the closed state at all times, so as alternatively to use only one of the two LLC resonant converters to charge the battery according to the first charging power level, based on the sign of the input current.

4. The method according to claim 3 , wherein each time the sign of the input current alternates, the control of the unused LLC resonant converter is cut.

5. The method according to claim 2 , wherein the switches of the switching arms corresponding to the first and second phase connections of the charging device connected to the single-phase electrical grid are systematically switched as a function of the sign of the input current, so as to use the two LLC resonant converters jointly to charge the battery according to the first charging power level.

6. The method according to claim 5 , wherein during a positive alternation of the input current, the high switch and the low switch of the switching arms respectively corresponding to the first and second phase connections of the charging device are made to switch together and, during a negative alternation of the input current, the low switch and the high switch of the switching arms respectively corresponding to the first and second phase connections of the charging device are made to switch together.

7. The method according to claim 1 , wherein, in a second single-phase connection mode, corresponding to a second single-phase charging power level from among at least three charging power levels from low to high, a first and second of the three phase connections of the charging device are respectively connected to a phase and neutral wire of the single-phase electric grid, the second phase connection being connected to the neutral wire by a first connection relay, and one connects the first and third phase connection together by a second connection relay.

8. The method according to claim 7 , wherein the status is systematically kept closed for the switches of the switching arm corresponding to the second phase connection of the charging device connected to the neutral wire, and the switches of the switching arm corresponding to the first and third phase connections of the charging device connected together are systematically switched as a function of the sign of the input current, so as to alternatively use only one of the two LLC resonant converters to charge the battery according to the second charging power level, based on the sign of the input current.

9. The method according to claim 8 , wherein during a positive alternation of the input current, the high switches of the switching arm respectively corresponding to the first and third phase connections of the charging device connected together are switched together and, during a negative alternation of the input current, the low switches of the switching arms respectively corresponding to the first and third phase connections of the charging device connected together are switched together.

10. The method according to claim 7 , wherein the switches of the switching arm corresponding to the first, second and third phase connections of the charging device connected to the single-phase electric grid are systematically switched based on the sign of the input current, so as to use the two LLC resonant converters jointly to charge the battery according to the second charging power level.

11. The method according to claim 1 , wherein, in a third single-phase connection mode, corresponding to a third single-phase charging power level from among at least three charging power levels from low to high, a first of the three phase connections of the charging device is connected to a phase wire of the single-phase electric grid and the second and third phase connections of the charging device are connected to said phase wire of the single-phase electric grid by a respective connection relay, the midpoint of the three-phase Vienna rectifier being connected to the neutral wire of the single-phase electric grid.

12. The method according to claim 11 , wherein only one of the two LLC resonant converters is used to charge the battery according to the third charging power level based on the sign of the input current, and the switches of the switching arms corresponding to the first, second, and third phase connections of the charging device connected to one another are systematically switched based on the sign of the input current.