Direct current hybrid circuit breaker with reverse biased voltage source

Patent metadata

Field	Value
Publication number	US-12444920-B2
Application number	US-202218070896-A
Country	US
Kind code	B2
Filing date	Nov 29, 2022
Priority date	Nov 29, 2021
Publication date	Oct 14, 2025
Grant date	Oct 14, 2025

Abstract

A direct current (DC) hybrid circuit breaker (HCB) includes a current sensor and a variable inductor. In the event of a short circuit fault current reaches a preset threshold, the current sensor will send a tripping signal to a controller, and the controller will command the gate drivers to conduct all the switches in the semiconductor switch path. This action will allow the fault current to be commuted to the power stack. When the current in a fast mechanical switch branch drops to near zero, the variable inductor will be driven out of the saturation and the secondary winding will send out a “safe-to-open” signal to the controller. After receiving the “safe-to-open” signal, the controller will initiate the turn off sequence of the fast mechanical switch path.

First claim

What is claimed is:

1. A direct current (DC) hybrid circuit breaker (HCB), comprising:
an input;
an output;
a mechanical switch path comprising a current sensor, a mechanical switch and a variable inductor in series with the mechanical switch and the current sensor, wherein the mechanical switch path is coupled between the input and the output;
a semiconductor switch path comprising a semiconductor switch connected in series with a commutation unit, the semiconductor switch path in parallel with the mechanical switch and the variable inductor; and
a controller communicatively coupled to the current sensor, wherein the controller is further coupled to the semiconductor switch in the semiconductor switch path for controlling closing and opening of the semiconductor switch path, wherein the variable inductor is communicatively connected to the controller, such that variable inductor provides a signal to the controller upon being driven out of saturation, wherein the controller provides a signal to the semiconductor switch to open the semiconductor switch.

2. The DC-HCB of claim 1 , wherein the commutation unit comprises a voltage in parallel with a capacitor in parallel with a diode such that when the mechanical switch is open, the variable inductor desaturates.

3. The DC-HCB of claim 2 , wherein the diode is biased such that voltage on the variable inductor drains and is configured to supply a reverse biased voltage source on the semiconductor switch path, wherein the semiconductor switch is opened.

4. The DC HCB of claim 1 , wherein the current sensor provides a signal to the controller upon determining that current through the current sensor has crossed a predetermined threshold.

5. The DC HCB of claim 4 , wherein the predetermined threshold is an upper current threshold, wherein, when the current crosses the upper threshold, the current sensor sends a signal to the controller and the controller provides a signal to the semiconductor switch to close the semiconductor switch.

6. The DC HCB of claim 1 , wherein the semiconductor switch comprises a gate-controlled semiconductor.

7. The DC HCB of claim 6 , wherein the controller is coupled with a gate of the semiconductor to provide a control signal to the gate, thereby causing the semiconductor switch to close.

8. The DC HCB of claim 1 , wherein the commutation unit comprises:
a capacitor;
an input of the commutation unit, where the input of the commutation unit is coupled to a negative terminal of the capacitor;
an output of the commutation unit;
a first switch connected in parallel with the capacitor.

9. The DC HCB of claim 8 , wherein the switch is a diode.

10. The DC HCB of claim 8 , wherein the commutation unit further comprises an adjustable charger connected in parallel with the capacitor and the switch.

11. A method of operating a direct current (DC) hybrid circuit breaker, the method comprising:
detecting an over-current condition in a switch current across a closed mechanical switch in a mechanical switch path of the DC HCB, the mechanical switch path comprising a variable inductor and a mechanical switch;
sending a signal from a current sensor in the mechanical switch path to a controller upon detecting the over-current condition;
the controller controlling a gate in a semiconductor switch in a semiconductor switch path to close, thereby causing current to flow in the semiconductor switch path, wherein the semiconductor switch path is connected in parallel with the mechanical switch path, thereby causing the variable inductor in the mechanical switch path to desaturate;
communicating a desaturation signal to the controller upon substantial desaturation of the variable inductor; and
the controller controlling the gate in the semiconductor switch to open the semiconductor switch upon receipt of the desaturation signal,
wherein the variable inductor is communicatively connected to the controller, such that variable inductor provides a signal to the controller upon being driven out of saturation, wherein the controller provides a signal to the semiconductor switch to open the semiconductor switch.

12. The method of claim 11 , wherein the semiconductor switch path includes a commutation unit having a voltage in parallel with a capacitor in parallel with a diode such that when the mechanical switch is open, the variable inductor desaturates.

13. The DC-HCB of claim 12 , wherein the diode is biased such that voltage on the variable inductor drains and is configured to supply a reverse biased voltage source on the semiconductor switch path, wherein the semiconductor switch is opened.

14. The method of claim 11 , the current sensor sending the signal to the controller upon determining that current through the current sensor has crossed a predetermined threshold.

15. The method of claim 14 , wherein the predetermined threshold is an upper current threshold, wherein, when the current crosses the upper threshold, the current sensor sends a signal to the controller and the controller provides a signal to the semiconductor switch to close the semiconductor switch.

16. The method of claim 11 , wherein the semiconductor switch comprises a gate-controlled semiconductor.

17. The method of claim 11 , wherein the controller is coupled with a gate of the semiconductor to provide a control signal to the gate, thereby causing the semiconductor switch to close.

18. The method of claim 11 , wherein the commutation unit comprises:
a capacitor;
an input of the commutation unit, where the input of the commutation unit is coupled to a negative terminal of the capacitor;
an output of the commutation unit;
a first switch connected in parallel with the capacitor.

19. The method of claim 18 , wherein the switch is a diode.

20. The method of claim 18 , wherein the commutation unit further comprises an adjustable charger connected in parallel with the capacitor and the switch.

Assignees

• Univ Florida State Res Found Inc

Inventors

• Steurer Michael Johann
• Shi Yanjun

Classifications

• H02H1/0007

  concerning the detecting means (in general G01R or other subclasses of G01; reed switches H01H71/2445) · CPC title

• H01H89/00

  Combinations of two or more different basic types of electric switches, relays, selectors and emergency protective devices, not covered by any single one of the other main groups of this subclass · CPC title

• H01H2009/543

  third parallel branch comprising an energy absorber, e.g. MOV, PTC, Zener · CPC title

• H02H3/087

  for DC applications · CPC title

• H02H3/08 Primary

  responsive to excess current (responsive to abnormal temperature caused by excess current H02H5/04) · CPC title