Electronic circuit breaker with self-triggering protection for vehicle and method therefor

Abstract

An electronic circuit breaker (100) with self-triggering protection for a vehicle, comprising: an input (101), the input being configured to be connected to a power DC power source; an output (102), the output being configured to be connected to a load; the input being connected to the output via a switch (103), the switch being controlled between an "on" state and an "off" state via a switch control line (106); a switch driver (104), the switch driver being connected to the switch control line, the switch driver being configured to control the switch; and characterized in that: the switch protection device ( 105); a voltage detection branch (203), the voltage detection branch being configured to output a first potential (Vn2) indicating a potential difference between the input and the output; a comparator circuit (201), the comparator circuit being configured to compare the first potential with a first threshold voltage, the first threshold voltage being indicative of an overcurrent level flowing through the switch; and a gate controller (202), the gate controller being connected to the switch disable line and being configured to disable the switch by connecting the switch control line to a potential that causes the switch to enter an "off" state.

Description

Technical Field

[0001] The present invention relates to an electronic circuit breaker with self-triggering protection for a vehicle, comprising: an input configured to be connected to a power direct current power source (DC power source); an output configured to be connected to a load; the input is connected to the output via a switch, the switch being controlled between an "ON" state and an "OFF" state via a switch control line; a switch driver connected to the switch control line, the switch driver being configured to control the switch.

[0002] The present invention also relates to a battery junction box comprising such an electronic circuit breaker and a battery pack comprising such a battery junction box. Background Art

[0003] Conventional electronic circuit breakers for vehicles typically employ current shunts in order to measure the current passing through the electronic circuit breaker and, if an overcurrent is detected, interrupt the current through a dedicated circuit. However, in vehicles utilizing modern high-energy propulsion batteries, such current shunts are quite expensive and require special safety measures. Furthermore, high-energy propulsion batteries require components to ensure safety in the event of a short circuit or other hazardous events. Safety is typically provided by a set of contactors and fuses. Contactors interrupt the circuit at moderate currents and fuses open at excessive currents. There are different types of fuses and contactors, and depending on the design, they provide different degrees of safety. If a solid-state circuit breaker is used in the protection system, the semiconductor switch will need to be externally triggered in order to clear the short circuit in the circuit, which also requires the use of a current sensing method.

[0004] It is therefore an object of the present invention to propose an electronic circuit breaker that can be used with high energy propulsion batteries, alleviating some of the above mentioned problems. Summary of the invention

[0005] The object of the present invention is achieved by an electronic circuit breaker with self-triggering protection for a vehicle as initially defined, the electronic circuit breaker being characterized by: a switch protection device connected between an input and an output and in parallel with a switch, the switch protection device also being connected to a switch control line, wherein the switch protection device comprises: an overvoltage protection branch extending from the input to the output; a voltage detection branch extending from the input to the output and configured to output a first potential indicating a potential difference between the input and the output; a comparator circuit configured to compare the first potential with a first threshold voltage, the first threshold voltage indicating an overcurrent level flowing through the switch, the overcurrent causing a voltage drop across the switch, the comparator circuit outputting a switch disable signal via a switch disable line when detecting that the first potential is higher than the first threshold voltage; and a gate controller connected to the switch disable line and configured to disable the switch by connecting the switch control line to a potential that causes the switch to enter an “off” state.

[0006] According to an embodiment, the comparator circuit is further configured to delay the switch disable signal for a predetermined time in order to determine that the first potential is above the first threshold voltage after the predetermined time and thereby indicate a short circuit at the output. This allows the electronic circuit breaker to distinguish between a permanent short circuit or a temporary overcurrent.

[0007] According to an embodiment, the voltage detection branch comprises: a first diode, whose cathode is connected to the input and whose anode is connected to a second node; the second node is connected to the first node via a first resistor; the first node is connected to the output via a second resistor; and the first potential is at the first node. This allows overcurrent detection without a current shunt.

[0008] According to one embodiment, the switch is a MOSFET, wherein the drain is connected to the input, the source is connected to the output, and the gate is connected to the switch control line; and the gate controller is configured to disable the MOSFET by connecting the switch control line to the output via a first resistor, and when the switch disable signal is received at the switch disable line, the MOSFET is placed in an "off" state.

[0009] According to an embodiment, the overvoltage protection branch comprises a snubber circuit, the snubber circuit comprising: a capacitor connected in series with a resistor and a diode connected in parallel with the resistor. The snubber circuit will actually clamp the voltage spike.

[0010] The object of the present invention is also achieved by a battery junction box for a battery pack of a vehicle. The battery junction box includes: a positive input terminal, the positive input terminal is configured to be connected to the positive pole of at least one battery module; a negative input terminal, the negative input terminal is configured to be connected to the negative pole of the battery module; a positive output terminal, the positive output terminal is configured to be connected to the negative output terminal via the load of the vehicle; the negative input terminal is connected to the negative output terminal via a fuse connected in series with a main switch; a rectifier circuit, the rectifier circuit includes a diode, the diode has a cathode connected to the positive output terminal, and an anode connected to the negative output terminal; and wherein the battery junction box is characterized by also including an electronic circuit breaker according to an embodiment of the present invention, wherein: the input of the electronic circuit breaker is connected to the positive input terminal: the output of the electronic circuit breaker is connected to the positive output terminal.

[0011] The object of the present invention is also achieved by a battery pack for a vehicle, the battery pack comprising at least one battery module having at least one battery cell, and the battery pack being characterized by comprising a battery junction box according to the present invention.

[0012] The object of the invention is also achieved by a vehicle which is characterized in that it comprises a battery pack according to the invention or an electronic circuit breaker according to the invention.

[0013] The object of the present invention is also achieved by a method for an electronic circuit breaker for a vehicle, wherein the electronic circuit breaker includes: an input, the input being configured to be connected to an electric DC power source; an output, the output being configured to be connected to a load; the input being connected to the output via a switch, the switch being controlled between an "on" state and an "off" state via a switch control line; and the method is characterized in that it includes the following steps: determining whether the switch is in the "on" state; when determining that the switch is in the "on" state, measuring a first potential indicating a current flowing from the input terminal to the output terminal; comparing the first potential with a first threshold voltage, the first threshold voltage indicating an overcurrent level of the switch, and if the first potential is greater than the first threshold, causing the switch to enter the "off" state.

[0014] According to one embodiment, the method further includes the following steps: waiting for a predetermined time when it is determined that the first potential is greater than the first threshold; after waiting for the predetermined time, comparing the first potential with the first threshold voltage for a second time; when comparing the first potential with the first threshold for the second time, after the first potential is greater than the first threshold voltage for the second time, manipulating the switch to the "off" state.

[0015] Other features and advantages of the present invention will appear from the detailed description of the following embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is a schematic block diagram of an electronic circuit breaker according to an embodiment,

[0017] Figure 2 is a schematic circuit diagram of an electronic circuit breaker according to an embodiment,

[0018] Figure 3 is a schematic block diagram of a battery junction box according to an embodiment and a battery pack including such a battery junction box,

[0019] Figure 4 is a schematic diagram of a vehicle having a battery pack according to an embodiment,

[0020] Figure 5 is a flowchart illustrating a method according to an embodiment, and

[0021] Figure 6 is a block diagram illustrating a machine and a computer readable memory. DETAILED DESCRIPTION

[0022] Figure 1 An electronic circuit breaker with self-triggering protection for a vehicle is shown, generally indicated at 100. The electronic circuit breaker comprises an input 101 configured to be connected to a power DC source, an output 102 configured to be connected to a load. The input is connected to the output via a switch 103, which is controlled between an "ON" state and an "OFF" state via a switch control line 106. A switch driver 104 is connected to the switch control line, and the switch driver is configured to control the switch.

[0023] Figure 2 The switch protection device 105 is shown in more detail, and the switch 103 is a MOSFET M0, wherein the drain D is connected to the input, the source S is connected to the output, and the gate G is connected to the switch control line 106. The gate controller is configured to disable the MOSFET by connecting the switch control line to the output via a first resistor R5, which causes the MOSFET M0 to enter an "off" state when the switch disable signal is received at the switch disable line.

[0024] The switch protection device 105 is connected between the input 101 and the output 102, in parallel with the switch 103, and is also connected to the switch control line 106. The switch protection device 105 includes: an overvoltage protection branch 204 extending from the input to the output; a voltage detection branch 203 extending from the input to the output and configured to output a first potential Vn2 indicating a potential difference between the input and the output; a comparator circuit 201 configured to compare the first potential with a first threshold voltage, the first threshold voltage indicating an overcurrent level flowing through the switch, the overcurrent causing a voltage drop across the switch, the comparator circuit outputting a switch disable signal via a switch disable line when detecting that the first potential is higher than the first threshold voltage; and a gate controller 202 connected to the switch disable line and configured to disable the switch by connecting the switch control line to a potential that causes the switch to enter an "off" state.

[0025] The comparator circuit 201 is further configured to delay the switch disable signal for a predetermined time in order to determine that the first potential is above the first threshold voltage after the predetermined time and thereby indicate a short circuit at the output. The delay is implemented as an RC circuit having a resistor R7 and a capacitor C3, as shown in FIG. Figure 2 shown.

[0026] In addition, Figure 2 In the comparator circuit 201, the voltage source E and the resistors R10 and R11 are used to set a first threshold voltage used in the first comparator UA1 for determining that the current indicated by the voltage Vn2 is greater than the first threshold. The voltage divider formed by the resistor R8 and the resistor R9 is also used to set a threshold value, which is compared with the delayed signal of the RC circuit formed by the resistor R7 and the capacitor C3 in the second comparator UA2, wherein the output from the comparator UA2 is connected to the gate controller 202 (the base of the transistor T1) via the resistor R6. The first comparator UA1 is used to detect overcurrent, and the second comparator is used to determine whether it is a temporary overcurrent or a permanent short circuit. The transistor T1 includes a base connected to the output of the comparator UA2 via the resistor R6, and the emitter of the transistor T1 is connected to the gate G of the MOSFET M0 and the switch controller. The collector of the transistor T1 is connected to the source of the MOSFET M0 via the resistor R5. In this way, the transistor T1 controls whether the switch driver 104 can control the MOSFET M0, because if the transistor T1 is activated, V gs The voltage (gate-source potential) becomes small enough to turn off the MOSFET M0.

[0027] The voltage detection branch 203 includes: a first diode D3, whose cathode is connected to the input and whose anode is connected to the second node n1. The second node n1 is connected to the first node n2 via a first resistor R3, the first node n2 is connected to the output via a second resistor R4, and the first node n2 is at a first potential Vn2. The voltage drop across the second resistor R4 indicates the current flowing through the MOSFET M0 when the MOSFET is in the "on" state.

[0028] The overvoltage protection branch 204 comprises a snubber circuit of the RCD type and includes a capacitor C1 connected in series with a resistor R1 and a diode D2 connected in parallel with the resistor. Other types and variations of snubber circuits may also be used in the overvoltage protection branch.

[0029] The switch protection device 105 is an automatic triggering device and does not require manual resetting after being triggered. When overcurrent is no longer detected, the switch protection device allows the switch driver 104 to control the MOSFET M0.

[0030] refer to Figure 3 , a battery junction box 300 of a battery pack 301 of a vehicle will now be described. The battery junction box 300 includes a positive input terminal 305 configured to be connected to the positive pole of at least one battery module 302, 303, and a negative input terminal 306 configured to be connected to the negative pole of the battery module 302, 303. The battery junction box also includes a positive output terminal 307, which is configured to be connected to a negative output terminal 308 via a load ZL of the vehicle, which load may be a DC link having an associated inverter and a motor connected thereto. The negative input terminal is connected to the negative output terminal via a fuse F0 connected in series with a main switch SW0. The battery junction box also includes a rectifier circuit 309, which includes a diode D1, whose cathode is connected to the positive output terminal and whose anode is connected to the negative output terminal; and wherein the battery junction box also includes a rectifier circuit 309 according to the present invention and with reference to Figure 1 and Figure 2 The electronic circuit breaker 100 is disclosed. The input of the electronic circuit breaker is connected to the positive input terminal 305 , and the output of the electronic circuit breaker is connected to the positive output terminal 307 .

[0031] Refer to the discussion above Figure 3 , discloses a battery pack 301 for a vehicle 400. The battery pack includes at least one battery module with at least one battery cell. In addition, the battery pack includes the above reference Figure 3 The main design of the battery junction box 300 is discussed.

[0032] Figure 4A vehicle 400 is shown, comprising a battery pack 301 according to the invention and described above. The battery junction box 300 is connected via a DC link to an inverter 401 which powers an electric motor 402.

[0033] exist Figure 5 In the invention, a method 500 for an electronic circuit breaker for a vehicle is disclosed. The electronic circuit breaker 100 comprises: an input 101 configured to be connected to a power DC power source; an output 102 configured to be connected to a load; the input is connected to the output via a switch 103, and the switch is controlled between an "on" state and an "off" state via a switch control line 106;

[0034] The method comprises the following steps:

[0035] Determine whether switch 501 is in the "on" state.

[0036] When determining that the switch is in the "on" state, measuring 502 a first potential Vn2 indicating a current flowing from the input terminal to the output terminal.

[0037] Comparing 503 the first potential Vn2 with a first threshold voltage, which indicates an overcurrent level of the switch, and bringing the switch into an "off" state if the first potential is greater than the first threshold.

[0038] Wait 504 for a predetermined time when it is determined that the first potential is greater than the first threshold.

[0039] After waiting for the predetermined time, compare 505 the first potential Vn2 with the first threshold voltage for the second time.

[0040] When the first potential is compared with the first threshold for the second time, after the first potential is greater than the first threshold for the second time, the switch is manipulated 506 to the “off” state.

[0041] Figure 6 A non-transitory computer readable medium 600 is disclosed, containing information including information for a machine 601 to perform the above-referenced Figure 5 Instructions for the disclosed method.

Claims

1. An electronic circuit breaker (100) with self-triggering protection for a vehicle, comprising: an input (101) configured to be connected to a power DC power source; An output (102), the output being configured to be connected to a load; the input being connected to the output via a switch (103), the switch being controlled between an "on" state and an "off" state via a switch control line (106); a switch driver (104), the switch driver being connected to the switch control line, the switch driver being configured to control the switch; and characterized in that: a switch protection device (105), the switch protection device being connected between the input and the output and in parallel with the switch, the switch protection device being also connected to the switch control line, wherein the switch protection device comprises: an overvoltage protection branch (204 ), the overvoltage protection branch extends from the input to the output, wherein the overvoltage protection branch includes a buffer circuit, the buffer circuit includes a capacitor (C1) connected in series with a resistor (R1) and a diode (D2) connected in parallel with the resistor; a voltage detection branch (203), the voltage detection branch extends from the input to the output and is configured to output a first potential (Vn2) indicating a potential difference between the input and the output, wherein the voltage detection branch (203) includes a first diode (D3), wherein the cathode is connected to the input and the anode is connected to a second node (n1); the second node (n1) connected to a first node (n2) via a first resistor (R3); the first node (n2) is connected to the output via a second resistor (R4); and the first potential (Vn2) is at the first node (n2); a comparator circuit (201), the comparator circuit being configured to compare the first potential with a first threshold voltage, the first threshold voltage indicating an overcurrent level flowing through the switch, the overcurrent causing a voltage drop across the switch, the comparator circuit outputting a switch disable signal via a switch disable line when detecting that the first potential is higher than the first threshold voltage; a gate controller (202), the gate controller connected to the switch disable line and configured to disable the switch by connecting the switch control line to a potential that causes the switch to enter an "off" state; wherein the switch is a MOSFET (M0) with a drain (D) connected to the input and a source (S) connected to the output and a gate (G) connected to the switch control line (106); and the gate controller is configured to disable the MOSFET by connecting the switch control line to the output via a first resistor (R5), causing the MOSFET (M0) to enter an "off" state upon receiving the switch disable signal at the switch disable line.

2. The electronic circuit breaker according to claim 1, characterized in that: The comparator circuit is further configured to delay the switch disable signal for a predetermined time in order to determine that the first potential is above the first threshold voltage after the predetermined time and thereby indicate a short circuit at the output.

3. A battery junction box (300) for a battery pack (301) of a vehicle, comprising: A positive input terminal (305), the positive input terminal being configured to be connected to the positive pole of at least one battery module (302, 303); a negative input terminal (306), the negative input terminal being configured to be connected to the negative pole of the battery module (302, 303); a positive output terminal (307), the positive output terminal being configured to be connected to a negative output terminal (308) via a load (ZL) of the vehicle; the negative input terminal being connected to the negative output terminal via a fuse (F0) connected in series with a main switch (SW0); a rectifier circuit (309), the rectifier circuit comprising a diode (D1), the diode having a cathode connected to the positive output terminal, and an anode connected to the negative output terminal; and wherein the battery junction box is characterized by further comprising an electronic circuit breaker (100) according to any preceding claim, wherein: the input of the electronic circuit breaker is connected to the positive input terminal; and the output of the electronic circuit breaker is connected to the positive output terminal.

4. A battery pack (301) for a vehicle (400), the battery pack comprising at least one battery module having at least one battery cell; and the battery pack is characterized by comprising the battery junction box (300) according to claim 3.

5. A vehicle (400), characterized in that It comprises the battery pack according to claim 4 or the electronic circuit breaker according to claim 1 or 2.

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