Over-voltage protection circuit for electric vehicles
AssigneeAmple, Inc.
InventorManuel Cereijido Fernandez
Life of this patent
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Abstract
An over-voltage protection circuit is electrically connected to one or more batteries and to a high-voltage bus to power the electrical components of an electric vehicle. The over-voltage protection circuit is configured to produce a short-circuit path for current flowing through the high-voltage bus when the voltage across the high-voltage bus is higher than a threshold voltage. The short-circuit path significantly increases the current flowing through the high-voltage bus, which causes one or more fuses to interrupt current flow. The over-voltage protection circuit includes an energy-harvesting circuit that down-converts the voltage across the high-voltage bus to a lower voltage that can power one or more electrical components of the over-voltage protection circuit.
Claims21
An over-voltage protection circuit comprising:
- a fuse having a first terminal electrically connected to one or more batteries and a second terminal electrically connected to a high-voltage bus to power a motor;
- a trigger circuit electrically connected to the high-voltage bus, the trigger circuit having a conducting state when a voltage of the high-voltage bus is higher than a threshold voltage and a non-conducting state when a voltage of the high-voltage bus is lower than the threshold voltage;
- an energy-harvesting circuit electrically connected to the high-voltage bus;
- a driver circuit electrically connected to an output of the trigger circuit and an output of the energy-harvesting circuit;
- a gate-hold circuit electrically connected to an output of the driver circuit and the output of the energy-harvesting circuit;
- and
- a short-circuit path electrically connected to an output of the gate-hold circuit, the short-circuit path having a first state in which the short-circuit path is electrically disconnected from the high-voltage bus and a second state in which the short-circuit path is electrically connected to the high-voltage bus,
- wherein when the trigger circuit is in the conducting state, one or more transistors in the driver circuit is/are activated to charge a buffer capacitor in the gate-hold circuit, the buffer capacitor producing a buffer-capacitor voltage that is higher than a threshold voltage of the short-circuit path to thereby transition the short-circuit path from the first state to the second state, the short-circuit path in the second state causing a current through the high-voltage bus to increase above a current rating of the fuse to electrically disconnect the one or more batteries from the high-voltage bus.
An over-voltage protection circuit comprising:
- a plurality of fuses, each fuse having a respective first terminal electrically connected to a respective battery and a second terminal electrically connected to a high-voltage bus to power a motor;
- a trigger circuit electrically connected to the high-voltage bus, the trigger circuit having a conducting state when a voltage of the high-voltage bus is higher than a threshold voltage and a non-conducting state when a voltage of the high-voltage bus is lower than the threshold voltage;
- an energy-harvesting circuit electrically connected to the high-voltage bus;
- a driver circuit electrically connected to an output of the trigger circuit and an output of the energy-harvesting circuit;
- a gate-hold circuit electrically connected to an output of the driver circuit and the output of the energy-harvesting circuit;
- and
- a short-circuit path electrically connected to an output of the gate-hold circuit, the short-circuit path having a first state in which the short-circuit path is electrically disconnected from the high-voltage bus and a second state in which the short-circuit path is electrically connected to the high-voltage bus,
- wherein when the trigger circuit is in the conducting state, one or more transistors in the driver circuit is/are activated to charge a buffer capacitor in the gate-hold circuit, the buffer capacitor producing a buffer-capacitor voltage that is higher than a threshold voltage of the short-circuit path to thereby transition the short-circuit path from the first state to the second state, the short-circuit path in the second state causing a current through the high-voltage bus to increase above a current rating of one or more respective fuses to electrically disconnect one or more respective batteries from the high-voltage bus, the one or more respective batteries causing the voltage of the high-voltage bus to be higher than the threshold voltage.
Dependencies are inferred from the claim text.