Semiconductor circuit interruption devices using current filtering to improve device coordination
An apparatus includes a semiconductor switch configured to interrupt a current between a power source and a load, an inductor coupled in series with the semiconductor switch, and a capacitor coupled to a node between the inductor and the load. The apparatus further includes a current sensor configured to sense a current provided to the load and a control circuit coupled to the current sensor and configured to control the semiconductor switch responsive to the sensed current.
1. An apparatus comprising:
a circuit breaker comprising a semiconductor switch configured to interrupt a current between a power source and a load;
an inductor coupled in series with the semiconductor switch;
a capacitor coupled to a node between the inductor and the load;
a current sensor configured to sense a current provided to the load from the node; and
a control circuit coupled to the current sensor and configured to determine a rate of change of the sensed current and to open the semiconductor switch responsive to the determined rate of change of the sensed current exceeding a rate of change threshold.
2. The apparatus of claim 1 , wherein the control circuit is configured to determine the rate of change threshold responsive to a voltage applied by the power source.
3. The apparatus of claim 1 , wherein the control circuit is configured to adjust the rate of change threshold responsive to the sensed current.
4. The apparatus of claim 1 , wherein the power source comprises another circuit breaker.
5. A circuit interruption device comprising:
an input port configured to be coupled to a power source;
an output port configured to be coupled to a load;
a semiconductor switch configured to interrupt a current between the input port and the output port;
an inductor coupled in series with the semiconductor switch;
a capacitor coupled to a node between the inductor and output port;
a current sensor configured to sense a current provided to the output port from the node; and
a control circuit coupled to the current sensor and configured to transition the semiconductor switch to a non-conducting state responsive to the sensed current indicating a fault, wherein the control circuit is configured to determine a rate of change of the sensed current and to open the semiconductor switch responsive to the determined rate of change of the sensed current exceeding a rate of change threshold.
6. The circuit interruption device of claim 5 , wherein the control circuit is configured to determine the rate of change threshold responsive to a voltage applied by the power source.
7. The circuit interruption device of claim 5 , wherein the control circuit is configured to adjust the rate of change threshold responsive to the sensed current.
8. The circuit interruption device of claim 5 , wherein the power source comprises a circuit breaker.
9. A circuit breaker comprising:
an input port configured to be coupled to a power source;
an output port configured to be coupled to a load;
a semiconductor switch configured to interrupt a current between the input port and the output port;
a low-pass filter coupled in series with the semiconductor switch;
a current sensor configured to sense a current provided to the output port from the low-pass filter; and
a control circuit coupled to the current sensor and configured to control the semiconductor switch responsive to the sensed current indicating a fault, wherein the control circuit is configured to determine a rate of change of the sensed current and to open the semiconductor switch responsive to the determined rate of change of the sensed current exceeding a rate of change threshold.
10. The circuit breaker of claim 9 , wherein the control circuit is configured to determine the rate of change threshold responsive to a voltage applied by the power source.
11. The circuit breaker of claim 9 , wherein the control circuit is configured to adjust the rate of change threshold responsive to the sensed current.