Overcurrent protection based on slope detection
Disclosed is a control circuit, for use in a solid state battery disconnect and protection system, wherein control circuit includes a high-voltage switch coupled between an electric battery and a DC link capacitor of an electric vehicle, wherein the electric vehicle is powered by the electric battery, and a control block. The control block may by operable to monitor a rate of change and a value of a current on a connection to the high-voltage switch, determine whether the rate of change of the current exceeds a first predetermined threshold and determine whether the value of the current exceeds a second predetermined threshold, and determine an overcurrent fault exists in the case that the first or second predetermined threshold is exceeded.
1 . A control circuit for use in a solid-state battery disconnect and protection system, the control circuit comprising:
a high-voltage switch coupled between an electric battery and a DC link capacitor of an electric vehicle, wherein the electric vehicle is powered by the electric battery; and
a control block operable to:
monitor a rate of change and a value of a current on a current path;
determine whether the rate of change of the current exceeds a first predetermined threshold and determine whether the value of the current exceeds a second predetermined threshold; and
determine an overcurrent fault exists in the case that the first or second predetermined threshold is exceeded, wherein the first predetermined threshold is exceeded before the second predetermined threshold.
2 . The control circuit of claim 1 , wherein the control block is further operable to open the high-voltage switch when the overcurrent fault is determined.
3 . The control circuit of claim 1 , wherein the control block is further operable to reset the high-voltage switch following the overcurrent fault.
4 . The control circuit of claim 1 , wherein the control block further comprises a current measurement circuit, and wherein the current measurement circuit comprises an overcurrent detector operable to determine the value of the current and a slope detector operable to determine the rate of change of the current.
5 . The control circuit of claim 1 , wherein the rate of change comprises a rate of increase.
6 . A control circuit for use in a solid-state battery disconnect and protection system, the control circuit comprising:
a high-voltage switch coupled between an electric battery and a DC link capacitor of an electric vehicle, wherein the electric vehicle is powered by the electric battery; and
a control block operable to:
monitor a rate of increase and a value of a current on a connection to the high-voltage switch;
determine whether the rate of increase of the current exceeds a first predetermined threshold and determine whether the value of the current exceeds a second predetermined threshold; and
determine an overcurrent fault exists in the case that the first or second predetermined threshold is exceeded, wherein the first predetermined threshold is exceeded before the second predetermined threshold.
7 . The control circuit of claim 6 , wherein the control block is further operable to open the high-voltage switch when the overcurrent fault is determined.
8 . The control circuit of claim 6 , wherein the control block is further operable to reset the high-voltage switch following the overcurrent fault.
9 . The control circuit of claim 6 , wherein the control block further comprises a current measurement circuit, and wherein the current measurement circuit comprises an overcurrent detector operable to determine the value of the current and a slope detector operable to determine the rate of increase of the current.
10 . The control cicuit of claim 9 , wherein the control block further comprises logic and a gate drive operable to open the high-voltage switch when the overcurrent fault is determined.
11 . A control circuit for use in a solid-state battery disconnect and protection system, the control circuit comprising:
a high-voltage switch coupled between an electric battery and a DC link capacitor of an electric vehicle, wherein the electric vehicle is powered by the electric battery; and
a control block operable to:
monitor a rate of change on a connection to the high-voltage switch;
monitor a value of a current on the connection to the high-voltage switch;
determine whether the rate of change of the current on the connection exceeds a first predetermined threshold and determine whether the value of the current on the connection exceeds a second predetermined threshold;
determine an overcurrent fault exists in the case that the first or second predetermined threshold is exceeded, wherein the first predetermined threshold is exceeded before the second predetermined threshold; and
open the high-voltage switch when the overcurrent fault is determined.
12 . The control circuit of claim 11 , wherein the control block is further operable to reset the high-voltage switch following the overcurrent fault.
13 . The control circuit of claim 11 , wherein the control block further comprises a current measurement circuit, and wherein the current measurement circuit comprises:
an overcurrent detector operable to determine the value of the current; and
a slope detector operable to determine the rate of change of the current.
14 . The control cicuit of claim 13 , wherein the control block further comprises logic and a gate drive operable to open the high-voltage switch when the overcurrent fault is determined.