Electrical power system
There is provided an electrical power system comprising: a DC voltage source, a DC electrical network, a DC to AC to DC converter having a primary side connected to the DC voltage source and a secondary side connected to the DC electrical network, and a controller configured to control the DC to AC to DC converter, wherein the controller is configured to: monitor an electrical current or voltage between the DC voltage source and the DC electrical network; determine, based on the monitored electrical current or voltage, whether the DC electrical network is in a fault condition; and increase a switching frequency of the primary side of the DC to AC to DC converter in response to a positive determination that the DC electrical network is in a fault condition.
1. An electrical power system comprising:
a DC voltage source;
a DC electrical network;
a DC to AC to DC converter comprising:
a transformer;
a primary side comprising a plurality of first transistors and a first inductor connected between the DC voltage source and a primary winding of the transformer, the first inductor being connected in series with the primary winding; and
a secondary side comprising a plurality of second transistors and a second inductor connected between the DC electrical network and a secondary winding of the transformer, the second inductor being connected in series with the secondary winding; and
a controller configured to control the DC to AC to DC converter, and being further configured to:
monitor an electrical current or voltage between the DC voltage source and the DC electrical network;
determine, based on the monitored electrical current or voltage, whether the DC electrical network is in a fault condition; and
increase a switching frequency of the primary side of the DC to AC to DC converter in response to a positive determination that the DC electrical network is in a fault condition.
2. The electrical power system of claim 1 , wherein the controller is further configured to modify a duty cycle of the primary side of the DC to AC to DC converter in response to a positive determination that the DC electrical network is in the fault condition.
3. The electrical power system of claim 1 , wherein each of the plurality of first transistors and the plurality of second transistors comprises Silicon Carbide or Gallium Nitride.
4. The electrical power system according to claim 1 , wherein the controller is configured to increase the switching frequency of the primary side of the DC to AC to DC converter by a factor of at least 5 in response to a positive determination that the DC electrical network is in the fault condition.
5. The electrical power system according to claim 1 , wherein the controller is configured to increase the switching frequency of the primary side of the DC to AC to DC converter to at least 50 kHz in response to a positive determination that the DC electrical network is in the fault condition.
6. The electrical power system according to claim 1 , wherein the transformer has a leakage reactance of greater than 0.1 per-unit.
7. The electrical power system according to claim 1 , wherein the transformer has a leakage reactance of greater than 0.2 per-unit.
8. The electrical power system according to claim 1 , wherein the transformer has a leakage reactance of greater than 0.3 per-unit.
9. The electrical power system according to claim 1 , wherein the transformer has a non-magnetic core.
10. The electrical power system according to claim 1 , further comprising an external inductor connected in series to the primary winding and/or the secondary winding.
11. An aircraft power and propulsion system comprising the electrical power system of claim 1 .
12. An aircraft comprising the electrical power system of claim 1 .
13. A method of operating an electrical power system comprising a DC voltage source, a DC electrical network, and a DC to AC to DC converter comprising a transformer; a primary side comprising a plurality of first transistors and a first inductor connected between the DC voltage source and a primary winding of the transformer, the first inductor being connected in series with the primary winding; and a secondary side comprising a plurality of second transistors and a second inductor connected between the DC electrical network and a secondary winding of the transformer, the second inductor being connected in series with the secondary winding; the method comprising:
monitoring an electrical current or voltage between the DC voltage source and the DC electrical network;
determining, based on the monitored electrical current or voltage, whether the DC electrical network is in a fault condition;
increasing a switching frequency of the primary side of the DC to AC to DC converter in response to a positive determination that the DC electrical network is in a fault condition.
14. The method of claim 13 , further comprising:
modifying a duty cycle of the primary side of the DC to AC to DC converter in response to a positive determination that the DC electrical network is in the fault condition.
15. The method of claim 13 , wherein the switching frequency of the primary side of the DC to AC to DC converter is increased by a factor of between 5 to 10 in response to a positive determination that the DC electrical network is in the fault condition.
16. The method of any of claim 13 , wherein the switching frequency of the primary side of the DC to AC to DC converter is increased to at least 50 kHz in response to a positive determination that the DC electrical network is in the fault condition.
17. A controller for controlling a DC to AC to DC converter in an electrical power system that includes a DC voltage source; a DC electrical network; and a DC to AC to DC converter comprising: a transformer; a primary side comprising a plurality of first transistors and a first inductor connected between the DC voltage source and a primary winding of the transformer, the first inductor being connected in series with the primary winding; and a secondary side comprising a plurality of second transistors and a second inductor connected between the DC electrical network and a secondary winding of the transformer, the second inductor being connected in series with the secondary winding, wherein the controller is configured to:
monitor an electrical current or voltage between the DC voltage source and the DC electrical network of the electrical power system;
determine, based on the monitored electrical current or voltage, whether the DC electrical network is in a fault condition; and
increase a switching frequency of the primary side of the DC to AC to DC converter in response to a positive determination that the DC electrical network is in a fault condition.
18. The controller of claim 17 , wherein the controller is further configured to modify a duty cycle of the primary side of the DC to AC to DC converter in response to a positive determination that the DC electrical network is in the fault condition.
19. The controller of claim 17 , wherein the controller is configured to increase the switching frequency of the primary side of the DC to AC to DC converter by a factor of at least 5 in response to a positive determination that the DC electrical network is in the fault condition.
20. The controller of claim 17 , wherein the controller is configured to increase the switching frequency of the primary side of the DC to AC to DC converter to at least 50 kHz in response to a positive determination that the DC electrical network is in the fault condition.