Gate control circuit, power module and associated method

1. A gate control circuit comprising:

a gate input arranged to receive an input gate feed signal;

a gate output arranged to be connected, during normal operation, to a plurality of switching modules for controlling current through a main circuit, the gate output being connected to the gate input;

a power supply; and

a switch connected between the power supply and the gate output, the switch being arranged to close as a response to a failure for setting connected switching modules in a conducting state.

2. The gate control circuit according to claim 1 , further comprising:

a plurality of switching module outputs each arranged to be connected to a respective switching module for controlling current through a main circuit; and

a plurality of current disconnectors, each connected between a respective switching module output, and the gate output, wherein each one of the current disconnectors is arranged to assume a blocking state when a failure occurs in a corresponding switching module.

3. The gate control circuit according to claim 2 , wherein the switch is arranged to close as a response to any one of the switching modules failing as detected by a dropped voltage over the collector and emitter of the switching modules.

4. The gate control circuit according to claim 2 , wherein each one of the current disconnectors is arranged to assume a blocking state when a current through the current disconnector exceeds a threshold current.

5. The gate control circuit according to claim 2 , wherein the current disconnectors are fuses.

6. The gate control circuit according to claim 2 , wherein the current disconnectors are circuit breakers.

7. The gate control circuit according to claim 1 , wherein the power supply comprises a power converter connected to the main circuit.

8. The gate control circuit according to claim 1 , wherein the power supply comprises a battery.

9. The gate control circuit according to claim 1 , further comprising a Zener diode connected between the gate output and the main circuit.

10. The gate control circuit according to claim 1 , wherein the gate control circuit is further arranged to inform an external system when a failure occurs.

11. A power module comprising:

a gate control circuit according to claim 2 ; and

a plurality of switching modules connected to the switching module outputs of the gate control circuit.

12. A power module comprising:

a gate control circuit according to claim 1 ; and

a plurality of switching modules connected to the gate output of the gate control circuit.

13. The power module according to claim 11 , wherein the switching modules are connected in parallel to the main circuit.

14. The power module according to claim 11 , wherein each one of the switching modules comprises a plurality of power switches connected in parallel to the main circuit.

15. The power module according to claim 14 , wherein each one of the power switches is an insulated-gate bipolar transistor.

16. A method executed in a gate control circuit comprising a gate input, a power supply, a gate output connected, during normal operation, to a plurality of switching modules for controlling current through a main circuit, the gate output being connected to the gate input, the method comprising the step of:

closing a switch, arranged between the power supply and the gate output, as a response to a failure for setting connected switching modules in a conducting state.

17. The method according to claim 16 , further comprising the step of:

setting, as a response to a switching module failing, a current disconnector corresponding to the switching module which has failed in a blocking state.

18. The method according to claim 16 , further comprising the step of:

as a response to the switching module failing, informing a control device about a non-controllable state of the gate control circuit.