Electrical supply system

1. An electrical supply system comprising:

a voltage converter comprising:

a voltage converter input electrically coupled to a supply for receiving a supply signal, and

a voltage converter output for supplying an output signal, the output signal having a output voltage different to a supply voltage of the supply signal;

a diode including a diode input electrically coupled to the voltage converter output;

a bus electrically coupled to a diode output and at least one of a load or a store;

a voltage sensor for detecting the output voltage;

a current sensor for detecting a diode input current; and

an electronic processing device coupled to the sensors, and configured to:

monitor the diode input current and the output voltage, and

detect a fault in the electrical supply system based on at least the diode input current and output voltage.

2. The system of claim 1 , wherein the electronic processing device is further configured to isolate the supply from the bus in response to detection of a fault.

3. The system of claim 1 , wherein the electronic processing device is further configured to:

cause the output voltage to be lower than a bus voltage;

monitor the diode input current; and

detect a fault depending on the diode input current.

4. The system of claim 1 , wherein the electronic processing device is further configured to:

cause the output voltage to be lower than a bus voltage;

cause the output voltage to increase over a predefined time until the output voltage is greater than the bus voltage;

monitor changes in the diode input current; and

detect a fault depending on the change in diode input current.

5. The system of claim 1 , wherein the electronic processing device is further configured to:

cause the output voltage to be higher than a bus voltage;

monitor the diode input current; and

detect a fault depending on the diode input current.

6. The system of claim 1 , wherein the voltage converter at least:

is a DC/DC converter; or

includes a plurality of switches, a transformer, and a controller for controlling the switches to thereby selectively apply the supply signal to a transformer input to thereby generate the output signal at a transformer output.

7. The system of claim 6 , wherein the switches comprise at least one of a transistor or a metal oxide semiconductor field effect transistors.

8. The system of claim 6 , wherein the controller is configured to cause the switches to toggle to thereby periodically reverse the polarity of the supply signal applied to the transformer input.

9. The system of claim 6 , wherein the voltage converter further comprises a rectifier for coupling the transformer to the voltage converter output.

10. The system of claim 6 , wherein the electronic processing device is either the controller or coupled to the controller.

11. The system of claim 1 , wherein the electronic processing device is further configured to:

determine a bus voltage by either deriving a bus voltage from the output voltage or using a second voltage sensor for sensing a bus voltage; and

detect a fault in the electrical supply system based on the bus voltage.

12. A method of supplying electricity by an electronic processing device, the method comprising:

monitoring a diode input current, an output voltage, and a bus voltage of an electrical supply system, the electrical supply system comprising:

a voltage converter comprising:

a voltage converter input electrically coupled to a supply for receiving a supply signal, and

a voltage converter output for supplying an output signal, the output signal having a voltage different than a voltage of the supply signal;

a diode comprising a diode output and a diode input electrically coupled to the voltage converter output;

a bus electrically coupled to the diode output and at least one of a load a store;

a first voltage sensor for detecting the voltage of the output signal;

a current sensor for detecting a current at the diode input; and

detecting a fault in the electrical supply system based on the diode input current, and depending on the output and bus voltages.

13. The method of claim 12 , wherein the method further comprises:

causing the output voltage to be lower than the bus voltage;

monitoring the diode input current; and

detecting a fault depending on the diode input current.

14. The method of claim 12 , wherein the method further comprises:

causing the output voltage to be lower than the bus voltage;

causing the output voltage to increase over a predefined time until the output voltage is greater than the bus voltage;

monitoring changes in the diode input current; and

detecting a fault depending on the change in diode input current.

15. The method of claim 12 , wherein the method further comprises:

causing the output voltage to be higher than the bus voltage;

monitoring the diode input current; and

detecting a fault depending on the diode input current.

16. An electrical supply system comprising a DC bus connected to an output of a voltage converter by an output diode and a controller, wherein the controller is configured to perform at least one of the following:

attempting to detect a shunt arc by:

reducing the voltage converter output voltage to a preset voltage below the DC bus voltage;

measuring current flow; and,

detecting a shunt arc if current flows; or

attempting to detect a series arc by:

attempting to increase the output voltage of the voltage converter to a preset voltage above the DC bus voltage;

measuring the change of the voltage;

detecting a series arc if the voltage rises above the DC bus voltage and a threshold amount.

17. A method of detecting a fault in an electrical supply system including a DC bus connected to the output of a voltage converter by an output diode, the method comprising at least one of the following steps:

attempting to detect a shunt arc by:

reducing the voltage converter output voltage to a preset voltage below the DC bus voltage;

measuring current flow; and,

detecting a shunt arc if current flows; or

attempting to detect a series arc by:

attempting to increase the output voltage of the voltage converter to a preset voltage above the DC bus voltage;

measuring the change of the voltage; and

detecting a series arc if the voltage rises above the DC bus voltage and a threshold amount.