System and method for the conversion of DC electric power into three-phase AC electric power, with filtering means
The present invention relates to a system for the conversion of DC electric power into three-phase electric power comprising three commutation arms (A, B, C), a modulation circuit, an electrical energy recovery module ( 8 ) and filtering means ( 7 ). The filtering means ( 7 ) comprise a capacitor (Cf) and an assembly formed from a filtering coil (Lf) connected in series with a diode (D).
1. A system for the conversion of DC electrical power into three-phase AC electrical power comprising three commutation arms, a modulation circuit for reducing switching loss and overshoot of voltage and current comprising one capacitor per AC output phase of the system and a coil, and an electrical energy recovery module connected to the commutation arms and to the modulation circuit, wherein the conversion system comprises a filtering circuit for each output phase of the system including a capacitor and an assembly formed from a filtering coil connected in series with a diode.
2. A system according to claim 1 , wherein the filtering coil has an inductance ranging between 0.5 and 50 microH.
3. A system according to claim 2 , wherein the diode of the filtering circuit is a Schottky diode.
4. A system according to claim 2 , wherein each assembly of the filtering circuit formed is mounted on a filtering module.
5. A system according to claim 2 , wherein the filtering circuits are positioned between the commutation arms and the electrical energy recovery module.
6. A system according to claim 1 , wherein the diode of the filtering circuit is a Schottky diode.
7. A system according to claim 6 , wherein the filtering circuits are positioned between the commutation arms and the electrical energy recovery module.
8. A system according to claim 1 , wherein each assembly of the filtering circuit formed is mounted on a filtering module.
9. A system according to claim 8 , wherein each assembly of the filtering circuit formed is mounted on a filtering module.
10. A system according to claim 8 , wherein the filtering circuits are positioned between the commutation arms and the electrical energy recovery module.
11. A system according to claim 8 , wherein the electrical energy recovery module includes at least one inductance and at least one commutator.
12. A system according to claim 1 , wherein each filtering module is mounted on a printed circuit board, comprising the commutation arms, the modulation circuit and the electrical energy recovery module.
13. A system according to claim 12 , wherein the filtering circuits are positioned between the commutation arms and the electrical energy recovery module.
14. A system according to claim 1 , wherein the filtering circuits are positioned between the commutation arms and the electrical energy recovery module.
15. A system according to claim 14 , wherein the electrical energy recovery module includes at least one inductance and at least one commutator.
16. A system according to claim 1 , wherein the electrical energy recovery module includes at least one inductance and at least one commutator.
17. A system according to claim 16 , wherein the electrical energy recovery module comprises three branches connected to a single junction point (P), including:
a first branch comprising a commutator;
a second branch comprising a diode; and
a third branch comprising an inductance.
18. A system according to claim 1 , wherein the coil of the modulation circuit is positioned between a DC input phase of the conversion system and a junction of the commutation arms.
19. System according to claim 18 , wherein each capacitor of the modulation circuit is connected to one AC output phase of the conversion system and to a junction between the coil of the modulation circuit, the commutation arms and a capacitor.
20. A system according to claim 19 , wherein the electrical energy recovery module is positioned between a DC input phase of the conversion system and the junction between the commutation arm and the capacitor of the modulation circuit.
21. A system according to claim 1 , wherein each commutation arm includes two commutators and two diodes with the output phases of the conversion system being connected to a mid-point of each commutation arm.
22. A system according to claim 1 , wherein the conversion system is bidirectional.
23. A motor system comprising at least one electrical energy storage and a three-phase electrical machine, wherein the motor system comprises a conversion system according to claim 1 for converting DC electrical energy from the electrical energy storage into three-phase AC electrical energy for the electrical machine.