Multi-phase inverter and related high voltage topology

1. An electrical system for operating an AC electric motor in conjunction with a DC electrical energy storage and a DC electrical energy source, the system comprising a multi-phase inverter or a set of inverters, wherein multiple AC phases of the inverter or the set of inverters are adapted to be coupled to the motor, and separate DC connections of the inverter or the set of inverters are adapted to be coupled to the DC electrical energy source and the DC electrical energy storage, and at least one DC-DC converter connected to at least one of the DC electrical energy source or the DC electrical energy storage.

2. The system of claim 1 , wherein multiple AC phases of the inverter or the set of inverters adapted to be coupled to the DC electrical energy source are electrically connected to multiple AC phases of the inverter or the set of inverters coupled to the DC electrical energy storage.

3. The system of claim 1 , wherein AC phases of the inverter or the set of inverters adapted to be coupled to the DC electrical energy source are not electrically connected to an inverter coupled to the DC electrical energy storage.

4. The system of claim 1 , wherein the DC electrical energy storage is a battery.

5. The system of claim 1 , wherein the DC electrical energy source is a fuel cell.

6. The system of claim 1 , wherein the inverter or the set of inverters are adapted to be coupled to additional DC electrical energy storage and/or additional DC electrical energy sources.

7. The system of claim 1 , wherein two H-bridges of the inverter or the set of inverters are additionally adapted to be electrically connected to a DC network.

8. The system of claim 1 , wherein at least two H-bridges of the inverter or the set of inverters are adapted to be electrically connected to an AC network.

9. The system of claim 8 , wherein three H-bridges of an inverter or inverters are adapted to be electrically connected to the AC network.

10. An electrically-driven motor vehicle comprising an AC electric drive or traction motor, a battery, a fuel cell, and a system according to claim 1 , wherein the system is electrically coupled to the electric motor, the battery and the fuel cell.

11. A method of operating an electrical system comprising an AC electric motor in conjunction with a DC electrical energy storage and a DC electrical energy source, the method comprising: coupling a multi-phase inverter or a set of inverters to provide multiple AC phases of electrical power to the motor, using separate DC connections of the inverter or the set of inverters to transfer electrical power to and from the DC electrical energy source and the DC electrical energy storage, and connecting at least one DC-DC converter to at least one of the DC electrical energy source or the DC electrical energy storage.

12. The method of claim 11 , further comprising electrically connecting multiple AC phases of the inverter or the set of inverters which transfers electrical power from the DC source to multiple AC phases of the inverter or the set of inverters which transfers electrical power to and from the DC storage.

13. The method of claim 11 , further comprising leaving AC phases of the inverter or the set of inverters which transfers electrical power from the DC source without electrical connection to AC phases of the inverter or the set of inverters which transfers electrical power to and from the DC storage.

14. The method of claim 11 , wherein the DC electrical energy storage is a battery.

15. The method of claim 11 , wherein the DC electrical energy source is a fuel cell.

16. An electrical system for operating an AC electric motor in conjunction with a DC electrical energy storage and a DC electrical energy source, the system comprising a multi-phase inverter or a set of inverters, wherein multiple AC phases of the inverter or inverters are adapted to be coupled to the motor, and separate DC connections of the inverter or the set of inverters are adapted to be coupled to the DC electrical energy source and the DC electrical energy storage, such that there is no DC electrical connection between the DC electrical energy source and the DC electrical energy storage, and at least two H-bridges of the inverter or the set of inverters are additionally adapted to be electrically connected to a DC network or to an AC network.