Solid state circuit interrupter
A circuit interrupter including a current sensor having a normal sensor output and an over current detection output, a solid state switch module structured to have a closed state to allow current to flow through the circuit interrupter and an open state to interrupt current flowing through the circuit interrupter, a gate driver structured to control the solid state switch module including a desaturation function output, wherein the gate driver is structured to cause the solid state switch module to interrupt current flowing through the circuit interrupter when the DESAT function output changes to the on state, and an electronic trip circuit structured to output a trip signal to the gate driver when the normal sensor output reaches a first threshold level or the overcurrent detection output changes to the on state.
1 . A circuit interrupter structured to be electrically connected between a power source and a load, the circuit interrupter comprising:
a frame including a number of compartments;
a number of solid state switch assemblies, each solid state switch assembly disposed in a corresponding one of the number of compartments and including:
an input terminal;
a first conductor;
an output terminal;
a second conductor; and
a solid state switch module electrically connected to the input terminal with the first conductor and electrically connected to the output terminal with the second conductor and including at least one solid state switch and a sensor;
a tripping device structured to trip the circuit interrupter to interrupt current flowing to the load in an event of a fault; and
a gate driver circuit including a desaturation function (DESAT) function output and structured to control a state of the solid state switch module based on a trip signal from the tripping device and a change of the DESAT function output to an on state, wherein the DESAT function output changes to the on state when the current flowing through the solid state switch module reaches a first threshold level,
wherein the sensor comprises a current sensor structured to sense current flowing through the circuit interrupter, the current sensor having a normal sensor output proportional to the current flowing through the circuit interrupter and an over current detection (OCD) output that changes to an on state when the current flowing through the circuit interrupter reaches a second threshold level.
2 . The circuit interrupter of claim 1 , wherein the tripping device includes an analog trip circuit structured to receive the OCD output and to output the trip signal to the gate driver circuit when the OCD output changes to the on state, the trip signal causing the gate driver circuit to control the solid state switch module to interrupt the current flowing through the circuit interrupter.
3 . The circuit interrupter of claim 2 , wherein the analog trip circuit is further structured to receive the normal sensor output and output the trip signal when the normal sensor output reaches a third threshold level, the trip signal causing the gate driver circuit to control the solid state switch module to interrupt the current flowing through the circuit interrupter.
4 . The circuit interrupter of claim 2 , wherein the tripping device also includes an electronic trip unit structured to output the trip signal to the gate driver circuit to cause the gate driver circuit to control the solid state switch module to open when the electronic trip unit detects a fault condition based on the normal sensor output.
5 . The circuit interrupter of claim 4 , further comprising:
separable contacts electrically coupled to the power source and the solid state switch module; and
an operating mechanism structured to open and close the separable contacts, wherein the electronic trip unit is further structured to control the operating mechanism to open or close the separable contacts.
6 . The circuit interrupter of claim 5 , wherein the separable contacts are structured to provide galvanic isolation between the power source and the load.
7 . The circuit interrupter of claim 6 , wherein the electronic trip unit is further structured to control the operating mechanism to open the separable contacts only after the solid state switch module has changed to an open state.
8 . The circuit interrupter of claim 7 , wherein the electronic trip unit is further structured to cause the gate driver circuit to change the solid state switch module to a closed state only after the separable contacts are closed.
9 . The circuit interrupter of claim 8 , wherein the electronic trip unit is further structured to receive an output of the gate driver circuit, the output indicative of the state of the solid state switch module.
10 . The circuit interrupter of claim 5 , further comprising a first position sensor structured to sense if the separable contacts are in an open position or a closed position, wherein the electronic trip unit is further structured to receive an output of the first position sensor and determine position of the separable contacts based on the output of the first position sensor.
11 . The circuit interrupter of claim 5 , further comprising an open switch and a second position sensor structured to sense actuation of the open switch, and wherein the electronic trip unit is further structured to control the solid state switch module to change from a closed state to an open state and subsequently control the operating mechanism to open the separable contacts in response to actuation of the open switch by the user based on output of the second position sensor.
12 . The circuit interrupter of claim 5 , further comprising a close switch and a third position sensor structured to sense actuation of the close switch, wherein the electronic trip unit is further structured to control the operating mechanism to close the separable contacts and subsequently control the solid state switch module to change to the closed state in response to actuation of the close switch by the user based on output of the third position sensor.
13 . The circuit interrupter of claim 1 , wherein each solid state switch assembly corresponds to a pole of the circuit interrupter.
14 . The circuit interrupter of claim 1 , wherein the sensor is structured to monitor a characteristic of the at least one solid state switch during operation, the characteristic comprising a junction temperature, a forward volt drop, a body diode forward volt drop, a gate threshold voltage or a gate leakage current of the at least one solid state switch.
15 . The circuit interrupter of claim 14 , further comprising an indication mechanism structured to indicate that the monitored characteristic has met a predetermined threshold, the indication mechanism including at least one of a display, an LED indicator, or a communication mechanism structured to communicate with an external device.
16 . A circuit interrupter structured to be electrically connected between a power source and a load, the circuit interrupter comprising:
a frame including a number of compartments;
a number of solid state switch assemblies, each solid state switch assembly disposed in a corresponding one of the number of compartments and including:
an input terminal;
a first conductor;
an output terminal;
a second conductor; and
a solid state switch module electrically connected to the input terminal with the first conductor and electrically connected to the output terminal with the second conductor and including at least one solid state switch and a sensor; and
a power supply structured to receive power from the power source and convert the power from the power source to power usable by components of the circuit interrupter,
wherein the sensor comprises a current sensor structured to sense current flowing through the circuit interrupter, the current sensor having a normal sensor output proportional to the current flowing through the circuit interrupter and an over current detection (OCD) output that changes to an on state when the current flowing through the circuit interrupter reaches a second threshold level.
17 . The circuit interrupter of claim 16 , wherein the power supply is structured to use line-line voltage from the power source to generate direct current power for use by the components of the circuit interrupter.
18 . The circuit interrupter of claim 17 , further comprising:
a tripping device structured to trip the circuit interrupter to interrupt current flowing to the load in an event of a fault; and
a gate driver circuit including a desaturation function (DESAT) function output and structured to control a state of the solid state switch module based on a trip signal from the tripping device and a change of the DESAT function output to an on state, wherein the DESAT function output changes to the on state when the current flowing through the solid state switch module reaches a first threshold level.
19 . The circuit interrupter of claim 16 , wherein the power supply includes a three-phase line input that receives power from multiple line phases.
20 . The circuit interrupter of claim 16 , further comprising a tripping device structured to trip the circuit interrupter to interrupt current flowing to the load in an event of a fault,
wherein the tripping device includes an analog trip circuit structured to receive the OCD output and to output the trip signal to a gate driver circuit when the OCD output changes to the on state, the trip signal causing the gate driver circuit to control the solid state switch module to interrupt the current flowing through the circuit interrupter.