Rapid battery disconnect system for high-current circuits

Abstract

Battery system (100), comprising: first and second fuses (106A, 106B), each comprising a first electrical connection and a second electrical connection; first and second contactors (104A, 104B), each comprising a first contactor connection and a second contactor connection; one or more battery cells (108) electrically coupled to a first battery module terminal and a second battery module terminal, wherein: the first battery module connection is electrically coupled in parallel with the first electrical connection of the first fuse (106A) and the first electrical connection of the second fuse (106B); the second electrical connection of the first fuse (106A) is electrically coupled to the first contactor connection of the first contactor (104A); the second electrical terminal of the second fuse (106B) is electrically coupled to the first contactor terminal of the second contactor (104B); and the second contactor terminal of the first contactor (104A) and the second contactor terminal of the second contactor (104B) are electrically coupled to each other; and a contactor control module (102), configured to: Maintaining a closed state of the first contactor (104A) and the second contactor (104B) in response to the detection of a current below a predetermined current level; Moving the first contactor (104A) to an open state while the second contactor (104B) remains in the closed state, in response to the detection of a current above the predetermined current level.

Description

CROSS-REFERENCE TO RELATED REGISTRATION

[0001] This disclosure claims the benefit of the preliminary US application No. 62 / 760,858, filed on November 13, 2018, which is hereby incorporated herein by reference in its entirety. INTRODUCTION

[0002] Electric vehicles typically include a high-capacity battery connected to a load, such as an electric drive unit. The voltage across the terminals of such batteries can exceed 300 V, and the operating current can exceed 500 A. Because a short circuit at the terminals can endanger the occupants of the electric vehicle and / or damage vehicle components, conventional electric vehicles include a fuse in series with the battery and the load to interrupt the short circuit. The fuse's rated current is usually selected based on the electric vehicle's maximum expected operating current. Due to the thermal, non-linear nature of conventional fuses, the rated current of a fuse increases, as does the time required for the fuse to break the circuit.Consequently, a conventional fuse cannot interrupt a circuit quickly enough to prevent damage to the circuit.

[0003] DE 10 2014 200 265 A1 discloses a battery system comprising a protection circuit with at least two circuit branches connected in parallel. Each circuit branch has a fuse and a current sensor connected in series with the fuse. The protection circuit is arranged in the main circuit of the battery, which runs from one high-voltage terminal of the battery, through the battery and optionally also through the contactor, to the other high-voltage terminal of the battery.

[0004] JP H09 284 902 A discloses an electric vehicle in which a connection between a main battery and the motor includes a first fuse and a second fuse, the second fuse having a lower nominal value than the first fuse. Relay contacts switch the first fuse between the main battery and the motor during acceleration, and the second fuse between the main battery and the motor when there is no acceleration. DE 10 2014 218 850 A1 discloses a battery arrangement with battery module groups connected in series, each group comprising two or more battery modules. A control device is configured to identify, in the event of a defect in a battery cell or battery module, the battery module group containing the defective battery cell or module and to disconnect the identified battery module group from the battery module groups connected in series.

[0005] US 2013 / 0181681A1 discloses a charge / discharge control device that can protect a battery cell from an overcurrent condition. The charge / discharge control device includes a protection element that protects the charging current path when a current value of the charging current path flowing through the switch exceeds a first protection current value, and a protection element that protects the discharging current path when a current value of the discharging current path flowing through the switch exceeds a second protection current value that is higher than the first protection current value. SUMMARY

[0006] The object of the present invention is to provide an improved battery system.

[0007] This problem is solved by the subject matter of claim 1.

[0008] Advantageous embodiments are the subject of the dependent claims.

[0009] In some embodiments, a battery system is provided. The battery system comprises two fuses, two contactors, and one or more battery cells. The two fuses, the two contactors, and the one or more battery cells each have two terminals. A first terminal of the one or more battery cells is electrically connected in parallel to a first electrical terminal of the first fuse and the second fuse. A second terminal of the first fuse is electrically connected to a first terminal of the first contactor, and a second terminal of the second fuse is electrically connected to a first terminal of the second contactor. A second terminal of the first contactor and a second terminal of the second contactor are electrically connected in parallel (e.g., via a busbar).The first fuse and the second fuse each comprise a locally minimal cross-sectional area configured to melt at a predetermined current, thereby interrupting a circuit when the current is exceeded.

[0010] In some embodiments, the battery system further includes a contactor control module configured to set at least one of the open and one of the closed states of the first and second contactors. In such embodiments, the contactor control module can control the state of the first and second contactors via control terminals of the respective contactors. In some embodiments, the contactor control module is configured to set one of the first and second contactors to the open state based on the detection of a current within a predetermined current range. In such embodiments, the predetermined current range can be between 2,400 and 5,000 amperes.In some embodiments, the contactor control module is configured to keep both the first and second contactors in the closed state based on the detection of a current greater than a predetermined current level. For example, in such embodiments, the predetermined current level may be at least 5,000 amperes.

[0011] In some embodiments, the battery system is located in an electric vehicle. In such embodiments, the contactor control module is further configured to detect a vehicle fault condition. In response to the detection of the vehicle fault condition, the contactor control module sets the first contactor to the open state and sets the second contactor to the closed state. While the vehicle fault condition is present, the electric vehicle can be operated in a reduced power mode.

[0012] In some embodiments, a busbar, which electrically couples the second terminals of the first and second contactors, provides switched current to the electric vehicle. In some embodiments, a third contactor is electrically coupled to the busbar via a first contactor terminal. The second contactor terminal is electrically coupled to a charging terminal.

[0013] In some embodiments, each of the first contactor terminals of a fourth and a fifth contactor is electrically coupled in parallel (e.g., via a busbar) to a second battery module terminal (e.g., a negatively charged terminal). A busbar can electrically couple the second contactor terminals of the fourth and fifth contactors in parallel and provide switched current to the electric vehicle.

[0014] In some embodiments, a first battery module terminal is electrically coupled to a positive terminal of one or more battery cells, and a second battery module terminal is electrically coupled to a negative terminal of one or more battery cells. The first and second battery module terminals can be unswitched terminals. In some embodiments, the voltage across the first and second battery module terminals is greater than 300 volts. The battery system can have a maximum operating current between 1,000 and 2,500 amperes. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The present disclosure is described in detail according to one or more different embodiments with reference to the following figures. The drawings are provided for illustrative purposes and represent only common or exemplary embodiments. These drawings are provided to facilitate understanding of the concepts disclosed herein and are not to be construed as limiting the breadth, scope, or applicability of these concepts. It should be noted that, for the sake of clarity and to simplify illustration, these drawings are not necessarily to scale. Fig. Figure 1 shows an exemplary configuration of contactors, fuses and battery cells according to some embodiments of the present disclosure; Fig. Figure 2 shows an additional exemplary configuration of contactors, fuses and battery cells according to some embodiments of the present disclosure; Fig. Figure 3 shows illustrative guards and fuses arranged according to some embodiments of the present disclosure; and Fig. Figure 4 shows an exemplary contactor control configuration according to some embodiments of the present disclosure. DETAILED DESCRIPTION

[0016] With advancements in battery technology, the voltage and operating current of electric vehicle battery modules have increased. A short circuit across the terminals of a high-performance electric vehicle battery module can endanger the vehicle's occupants and / or damage vehicle components. To protect occupants and electrical components, electric vehicles include a battery disconnect component, often a fuse, configured to cut power to the battery during an overcurrent event. Typically, the fuse's rated current is selected based on the electric vehicle's maximum expected operating current. Due to the thermal, non-linear nature of conventional fuses, the rated current of a fuse increases, as does the time required for the fuse to trip.Since damage caused by a short circuit event can be proportional to the duration of the event, the increased interruption time can lead to damage to the electric vehicle that could otherwise be prevented by faster disconnection.

[0017] The present disclosure relates to a system for rapidly disconnecting a battery pack from a circuit in the event of an overcurrent event. For example, an electrical circuit, such as one in an electric vehicle, may include a high-performance battery pack connected to a variety of electronics, such as one or more motors, controllers, air conditioning systems, lighting circuits, infotainment systems, etc., with a wiring harness electrically coupling the various electronics to the battery. If one or more of the components in the circuit experience an electrical fault (e.g.,(a short circuit in the wiring harness caused by a vehicle impact or a malfunction of one of the electronics), the battery disconnect system described herein can quickly disconnect the battery from the circuit to prevent or reduce the extent of damage to the circuit components due to the electrical fault.

[0018] Fig. Figure 1 represents an exemplary configuration of contactors, fuses, and battery cells according to some embodiments of the present disclosure. Configuration 100 comprises contactors 104A, 104B, and 110, contactor control module 102, fuses 106A and 106B, and battery module 108, arranged to reduce the time required to disconnect a battery from a load under various circuit currents. The exemplary system shown in configuration 100 includes at least two parallel fuse paths (e.g., a first path formed by contactor 104A and fuse 106A, and a second path formed by contactor 104B and fuse 106B) connected to a battery terminal (e.g., a battery terminal of battery module 108). The parallel path is connected by electrical coupling (e.g.,via a busbar) of a first fuse terminal of fuse 106A and a first fuse terminal of fuse 106B with a first battery terminal of battery module 108 (e.g. a positively charged terminal).

[0019] In some embodiments, the battery module 108 comprises a plurality of battery cells connected in series and in parallel, exhibiting a total potential exceeding 300 volts. In some embodiments, the total circuit current supplied by the battery module 108 can vary between 600 amperes and 1,000 amperes. Since the current is distributed approximately equally among the parallel fuse paths (e.g., the first path formed by contactor 104A and fuse 106A, and the second path formed by contactor 104B and fuse 106B), the rated current of each fuse is selected such that the rated current is less than a desired maximum operating circuit current (e.g., 600–1,000 amperes). For example, in a dual-fuse configuration, the current rating of each fuse is selected to be less than the desired maximum operating circuit current (e.g., 600–1,000 amperes). Fig. As shown in Figure 1, each of the 106A and 106B fuses is selected to have a rated current of approximately half (e.g., 300–500 amperes) of the desired maximum operating circuit current (e.g., 600–1,000 amperes). Due to the thermal characteristics of conventional fuses, each of the 106A and 106B fuses in the dual-fuse configuration (e.g., fuses with a rated current of approximately 300–500 amperes) has a significantly shorter breaking time than a conventional fuse with twice the rated current (e.g., a fuse with a rated current between 600–1,000 amperes) would have. Therefore, in the event of an overcurrent event exceeding 1,000 amperes, dual 500-ampere fuses would break a circuit faster than a single 1,000-ampere fuse.

[0020] Each of the protected parallel paths comprises a contactor connected in series with the fuse. For example, the first terminal of contactor 104A is electrically connected in series with the second terminal of fuse 106A, and the first terminal of contactor 104B is electrically connected with the second terminal of fuse 106B. The second terminal of both contactor 104A and contactor 104B can be electrically connected in parallel (e.g., via a busbar) to a load (e.g., a positive terminal of the load).

[0021] In some embodiments, a second set of contactors is electrically coupled to the load and the battery module. For example, a first contactor terminal of each of the contactors 110 can be electrically coupled to a second terminal of the battery module 108 (e.g., a negatively charged terminal) (e.g., via a busbar). A second contactor terminal of each of the contactors 110 can be electrically coupled in parallel to the load (e.g., a negative terminal of the load).

[0022] In some embodiments, each of the contactors 104A, 104B, and 110 is configurable to electrically couple or decouple the circuit from the battery terminal (e.g., based on a signal received by the contactor control module 102). Each contactor (e.g., contactors 104A, 104B, and 110) has a respective maximum disconnect current and can safely couple and decouple an electrical circuit while under a load less than the maximum disconnect current. If the load exceeds the maximum disconnect current, a contactor may be damaged when decoupling occurs. In some embodiments, each contactor (e.g., contactors 104A, 104B, and 110) includes a contactor control terminal that is electrically coupled to the contactor control module 102. In such embodiments, the contactor control module 102 controls an open and a closed state of the contactor.

[0023] In some embodiments, when the battery system detects an overcurrent event in the circuit that is less than the maximum disconnect current of each contactor, the contactor control module 102 can cause contactors 104A, 104B, and 110 to open, thus quickly decoupling the circuit from the battery without blowing the fuses. In some embodiments, in response to the detection of an overcurrent event below the maximum disconnect current of each contactor, the contactor control module can instruct one of contactors 110 or contactors 104A and 104B to open, thus decoupling either the first battery terminal or the second battery terminal of battery module 108 from the circuit.

[0024] In some embodiments, when the battery system detects an overcurrent event in the circuit that is greater than the maximum disconnecting current of each contactor but less than twice the maximum disconnecting current, the system can disconnect one parallel path from the battery terminal (e.g., the parallel path formed by contactors 104A and 106A). This causes the fuse in the second parallel path (e.g., fuse 106B) to exceed its rated current and blow, thus disconnecting the circuit. In some embodiments, the rated current of the fuses can be selected to be similar to the maximum disconnecting current of the contactors. Due to the lower rated current of the fuse (relative to a fuse requiring twice the rated current), the system is able to blow one of the parallel fuses more quickly than would be necessary for a single fuse requiring twice the breaking current.Since damage caused by a short-circuit event can be proportional to the duration of the event, reducing the interruption time can lead to reduced damage to the circuit. However, since the circuit's overcurrent event exceeds the maximum disconnect current for the contactor (e.g., contactor 104A), the contactor will be damaged during disconnection. In some embodiments, if the battery system is located in an electric vehicle, the battery system will maintain a record indicating that one of the contactors is damaged and notify an operator of the electric vehicle. In some embodiments, the electric vehicle will operate in a reduced-power mode (e.g., half the current for normal operation). Upon replacement of the damaged components, the system will resume normal operation.

[0025] In some embodiments, when the battery system detects an overcurrent event greater than twice the maximum disconnect current, the battery system, via the contactor control module 102, will hold contactors 104A, 104B, and 110 in a closed state, causing fuses 106A and 106B in the parallel paths to blow (e.g., because the rated current for the fuse is chosen to be less than or equal to the maximum disconnect current of the contactor).

[0026] Although the secured parallel paths are discussed in relation to a connection to a positive terminal of the battery, the secured parallel paths can instead be connected to a negative terminal of the battery. In some embodiments, a first set of parallel paths can be connected to the positive terminal of the battery, and a second parallel path can be connected to a negative terminal of the battery.

[0027] Fig. Figure 2 represents an additional exemplary configuration of contactors, fuses, and battery cells according to some embodiments of the present disclosure. In some embodiments, the contactors (e.g., contactors 104A, 104B, and 110), fuses (e.g., fuses 106A and 106B), contactor control module (e.g., contactor control module 102), and battery module (e.g., battery module 108) are, with respect to Fig. 1 are electrically equivalent to the corresponding components described in Fig. Figure 2 shows the configuration. In configuration 200, instead of the positive terminal of the battery module as in configuration 100, a fused parallel path is connected to a negative terminal of the battery module. The first terminal of a first fuse (e.g., fuse 206A) and a second fuse (e.g., fuse 206B) are electrically connected in parallel to a negative terminal of the battery (e.g., battery module 208).

[0028] Battery module 208 can comprise a plurality of battery cells connected in parallel and in series, exhibiting a total electrical potential exceeding 300 volts across a most positively charged terminal and a most negatively charged terminal of the battery module. A second terminal of the first fuse (e.g., fuse 206A) is electrically coupled to a first terminal of a first contactor (e.g., contactor 210A). A second terminal of the second fuse (e.g., fuse 206B) is electrically coupled to a first terminal of a second contactor (e.g., contactor 210B). The second terminals of the first and second contactors are electrically coupled in parallel. In some embodiments, the second terminals of the first and second contactors are electrically coupled in parallel to a busbar that supplies switched current to an electric vehicle.In some embodiments, the busbar is electrically coupled to a third contactor configured to control a battery charging circuit (see below in relation to ). Fig. 3 discussed).

[0029] A second, unsecured parallel path is connected to a positive terminal of the battery module 208. Each contactor's first terminal of contactor 204 is electrically coupled in parallel (e.g., via a busbar) to a positively charged terminal of battery 208. Although configuration 200 represents two contactors in the second parallel path (e.g., contactors 204), one or more contactors can be used without deviating from the scope of protection described in this disclosure. Each contactor's second terminal can be electrically coupled in parallel (e.g., via a busbar). In some embodiments, the second contactor terminals are electrically coupled to a load and / or a third contactor configured to control a battery charging circuit.

[0030] Although configurations 100 and 200 represent the protected parallel paths where a fuse terminal is electrically coupled to a battery in series with a contactor, the order of the fuse and contactor in series can change without altering the scope of protection described in this disclosure. For example, a first contactor terminal of a first contactor (e.g., contactor 104A or contactor 210A) can be electrically coupled to a positive terminal of a battery module (e.g., battery module 108 or 208). A second contactor terminal of the first contactor (e.g., contactor 104A or contactor 210A) can be electrically coupled to a first fuse terminal of a first fuse (e.g., fuse 106A or 206A). A second fuse terminal of the first fuse (e.g., fuse 106A or 206A) can be connected to a load and the second parallel path (e.g.,the series connection between fuse 106B and contactor 104B or the series connection between fuse 206B and 210B) be electrically coupled.

[0031] In some embodiments, when the contactor control module 102 or 202 detects a fault event (e.g., a vehicle impact or a short circuit), the contactor control module can adjust the state of the first contactor (e.g., contactor 104A or 210A) and / or the second contactor (e.g., contactor 104B or 210B) based on a measured current value in order to optimally minimize the disconnection time (further described in relation to Fig. 4 discussed). If the contactor control module detects a fault event and the circuit current is below the maximum contactor disconnect current (e.g., due to an impact), the contactor control module can open both contactors (e.g., contactors 104A and 104B or contactors 210A and 210B). If the contactor control module detects a current overload that is less than twice the maximum contactor disconnect current but greater than the maximum contactor disconnect current, the contactor control module can open a contactor on a first parallel path to increase the current on the second parallel path and thus overload the fuse on the second parallel path (e.g., contactor control module 202 can open contactor 210A and leave contactor 210B closed, causing fuse 206B to blow and interrupt the circuit).If the contactor control module detects a current overload exceeding twice the maximum contactor disconnect current, it can keep both contactors closed (e.g., both contactors 104A and 104B, or both contactors 210A and 210B). This causes the fuses (e.g., both fuses 106A and 106B, or both fuses 206A and 206B) on both parallel paths to be overloaded. By setting or maintaining an open or closed state for each contactor under varying current conditions, the system is able to optimally minimize the disconnection time.

[0032] Fig. Figure 3 shows illustrative contactors and fuses arranged according to some embodiments of the present disclosure. Arrangement 300 represents an exemplary protected parallel path (e.g., one of the parallel paths described in Fig. 1 and Fig. 2 are shown), which is coupled to a charging circuit. In arrangement 300, a busbar 306 electrically couples a first contactor terminal of the first contactor 302 and the second contactor 304 in parallel with a battery module terminal (e.g., a positive or negative terminal of the battery modules 108 and 208). In some embodiments, the contactors 302 and 304 can be connected in the manner described above with respect to the contactors 104A and 104B in Fig. 1 and the gunner 210A and 210B in Fig. 2. These measures are designed to reduce the circuit's disconnection time during an overcurrent event. In some embodiments, contactors 302 and 304 each include a contactor control terminal (e.g., contactor control terminal 322 and contactor control terminal 324) which is electrically connected to a contactor control module (e.g., contactor control module 102, shown in Figure 2). Fig. 1, or contactor control module 202, shown in Fig. 2) is coupled. The contactor control module can set the state of the contactors by sending a signal to open or close the contactors via the contactor control terminals 322 and 324.

[0033] In some embodiments, the contactor control module is configured to move the contactor to the open state (e.g., electrically disconnecting an internal connection between the first and second terminals of the contactor) or to the closed state (e.g., electrically coupling an internal connection between the first and second terminals of the contactor) based on a circuit current and / or a vehicle operating state. For example, when a user switches on the electric vehicle, the contactor control module can move contactor 302 and contactor 304 from an open state to a closed state. In another example, the contactor control module can move one or more of contactors 302 and 304 from a closed state to an open state based on the detection of an overcurrent event.In some embodiments, the contactor control module selects the number of contactors to be in an open state during an overcurrent event based on a detected circuit current (see below in relation to ). Fig. 4 discussed).

[0034] A second contactor terminal of the first contactor 302 is electrically coupled to a first fuse terminal of the first fuse 312 via a busbar 308. A second contactor terminal of the second contactor 304 is electrically coupled to a first fuse terminal of the second fuse 314 via a busbar 310. The respective second fuse terminals of the first fuse 312 and the second fuse 314 can be electrically coupled in parallel via a busbar 316. In some embodiments, the busbar 316 is electrically coupled to a load, such as an electric motor. A rated current of the fuses 312 and 314 can be, as above with respect to fuses 106A and 106B, Fig. 1 and fuses 206A and 206B in Fig. 2 can be selected as described. For example, if the expected maximum circuit current of the electric vehicle is 1,000 amperes, the rated current for each of the fuses 312 and 314 can be 500 amperes, half the maximum circuit current.

[0035] In some embodiments, the busbar 316 is additionally coupled to a charging contactor, such as a contactor 318, via a first contactor terminal. The charging contactor 318 can control the current flow for charging a battery module (e.g., battery module 108 or 208). The contactor control module (e.g., contactor control module 102 or 202) can control the open or closed state of the contactor 318 based on the battery's state of charge. For example, the battery control module (e.g., via the contactor control module 108 or 208) can set the contactor 318 to an open state (e.g., via the contactor control terminal 326) when the battery is not being charged and to a closed state when the battery is being charged.

[0036] Although Fig. Figure 3 shows parallel paths (e.g., where the first path includes contactor 302 and fuse 312, and the second path includes contactor 304 and fuse 314). One or more paths between the battery module and the load can exist without deviating from the scope of protection described in this disclosure. In some embodiments, a fuse is not placed in series with the contactors (e.g., in...). Fig. 1 as shooter 110 and in Fig. 2 shown as contactor 204). In such embodiments, the second contactor terminals of contactors 302 and 304 can be electrically coupled to the charging contactor (e.g. contactor 318) via the busbar 316 without having a connection to the busbars 308 and 310 or the fuses 312 and 314.

[0037] Fig. Figure 4 presents an exemplary contactor control diagram according to some embodiments of the present disclosure. Diagram 400 visually illustrates how the contactor control module can determine, based on the circuit current, whether or not to open one or more contactors during an overcurrent event. In diagram 400, the contactor control module places the contactors (e.g., contactors 302 and 304) into a first state 402 when the circuit current is below the first threshold 408; places the contactors into the second state 404 when the circuit current is within the first threshold 408 and a second threshold 410; and places the contactors into the third state 406 when the circuit current is above the second threshold 410. The various states and thresholds shown in diagram 400 can be determined based on the electrical parameters of components in the electric vehicle (e.g.,Rated currents of fuses and contactors, a maximum circuit current, disconnection times, etc., are selected and optimized to reduce the disconnection time during an overcurrent event and to protect the electric vehicle's components. For example, contactors may be able to interrupt a circuit faster than a fuse at the same circuit current. However, a contactor may only interrupt a circuit without damaging the contactor if the circuit current is below a certain threshold. In some overcurrent events, it may be more advantageous to interrupt a circuit by disconnecting both contactors, while in other circuit currents (e.g., where disconnection could damage a contactor), it may be more advantageous to keep one or more contactors closed and allow a fuse to blow.

[0038] In the first state (402), the contactor control module opens both contactors (e.g., contactors 302 and 304) in response to the detection of an overcurrent event that is less than the first threshold. For example, the contactors can safely interrupt a current of 2,400 amperes each without being damaged. The contactor control module can also instruct the contactors to open if the overcurrent event is less than 2,400 amperes without causing damage to the contactors. For example, the contactor control module can determine that the electric vehicle has been in an impact (e.g., based on communication from an impact detection system). If the circuit current is less than 2,400 amperes when the contactor control module detects the impact, the contactor control module instructs the first contactor (e.g., contactor 302) and the second contactor (e.g., contactor 304) to open.In some embodiments, the time to disconnect the current between the battery module and the load can be the sum of the time the control module takes to actuate the contactors (e.g., 50 ms) plus the time the contactor takes to open after receiving the control signal (e.g., 25 ms). Because the first and second contactors open without the fuses blowing or waiting for them to do so, the system is able to disconnect the battery module from the load faster than a comparable system using only fuses. Furthermore, because the contactors opened under a normal operating current (e.g., less than the first threshold current), the contactors and fuses may not need to be replaced before the vehicle is put back into service.

[0039] In the second state 404, the contactor control module opens one of the two contactors (e.g., contactor 302) and keeps the second contactor (e.g., contactor 304) closed when the current is above the first threshold 408 but below the second threshold 410. As discussed above, the first threshold can be selected based on the maximum current at which the contactor can safely disconnect a circuit under load without damaging the contactor (e.g., 2,400 amperes). Because the current is evenly distributed across both parallel paths, the contactors may be able to safely disconnect circuit currents under a higher load, twice the normal operating current (e.g., 5,000 amperes). However, under such loads, the open contactor may be damaged when disconnecting the circuit. In the second state 404, when the contactor control module instructs the first contactor to open (e.g.The current is routed through the second path (e.g., contactor 302), where the path includes contactor 304 and fuse 314. Since the circuit current (e.g., between 2,400 and 5,000 amperes) significantly exceeds the fuse's rated current (e.g., 1,000 amperes), the fuse blows and the circuit is interrupted. Under such conditions, the first contactor (e.g., contactor 302) can be damaged because it opened under a load exceeding 2,400 amperes.

[0040] In some embodiments, the contactor control module monitors current output from the battery (e.g., based on communication from a battery monitoring system, a motor controller, or by monitoring a change in current over time and can determine that the change in current over a given period exceeds a predefined value). For example, the contactor control module can detect a soft short circuit, such as a powertrain overcurrent event with a circuit current between the first threshold, 2,400 amperes, and the second threshold, 5,000 amperes. In some embodiments, the time required to interrupt the current between the battery module and the load can be the sum of the time the control module takes to actuate the contactors (e.g., 50 ms) plus the time the contactor takes to open after receiving the control signal (e.g., 25 ms) plus the time the fuse takes to blow at the circuit current (e.g., 50 ms).0.1 s) to blow. Due to the thermal nature of fuses, the interruption time can decrease with increasing circuit current.

[0041] In some embodiments, the battery system, in response to the detection of a vehicle fault condition, such as a soft short circuit, can operate the vehicle in a reduced-power mode (e.g., by using 50% of the normal operating current). In reduced-power mode, the battery system can open the first contactor and close the second contactor, thereby reducing the maximum operating current of the battery system by half. In such embodiments, the battery system can work in conjunction with other vehicle systems, such as the engine control unit, to keep the circuit current below the reduced maximum operating current.

[0042] In the third state 406, when the circuit current exceeds the second threshold 410, the contactor control module holds the first contactor (e.g., contactor 302) and the second contactor (e.g., contactor 304) in a closed state. For example, if the overcurrent event exceeds 5,000 amperes (e.g., based on a hard short circuit between the most positive switched terminal of the battery and the most negative switched terminal of the battery), the contactor control module may hold the first and second contactors closed, causing fuses 312 and 314 to blow. In the third state 406, the disconnection time is highly dependent on the fuse characteristics. For example, during a 5,000 ampere overcurrent event, the disconnection time for the two fuses may be an order of magnitude longer than the disconnection time during a 20,000 ampere overcurrent event.

[0043] In some embodiments, the battery system may additionally include at least one contactor that is electrically coupled to an unprotected terminal of the battery (in Fig. 1 as shooter 110 and in Fig. 2 shown as contactor 204). For example, the battery system may include a fourth and a fifth contactor, each having a first terminal electrically connected in parallel to a terminal of the battery (e.g., a negative terminal). The fourth and fifth contactors may each have a second terminal connected in parallel to a busbar. The busbar may be electrically connected to the load. In some embodiments, the contactor control module controls the state of the fourth and fifth contactors, as shown above. Fig. 4 described.

[0044] Although the examples above are discussed in relation to a dual contactor and dual fuse configuration, one or more contactors can be used. For example, some embodiments include three contactors with a first terminal electrically connected in parallel to a first battery terminal and a second terminal electrically connected in series with a first terminal of each fuse. A second terminal of each fuse may be electrically connected in parallel to a load. A second battery terminal may be electrically connected to one or more contactors (e.g., an unfused parallel combination of three contactors).Each of the contactors can include a respective contactor control connection, and a contactor control module can control the switching of the contactors to an open or closed state during an overcurrent event or impact to minimize a disconnection time between the battery module and the load.

[0045] The foregoing serves only to illustrate the principles of this disclosure, and various modifications may be made by a person skilled in the art without derogating from the scope of protection of this disclosure. The embodiments described above are presented for illustrative purposes and are not intended to be limiting. This disclosure may also take many other forms than those expressly described herein. Accordingly, it is emphasized that this disclosure is not limited to the expressly disclosed methods, systems, and devices, but is intended to include variations and modifications thereof that are within the spirit of the following claims.

Claims

[1] Battery system (100), comprising: first and second fuses (106A, 106B), each comprising a first electrical connection and a second electrical connection; first and second contactors (104A, 104B), each comprising a first contactor connection and a second contactor connection; one or more battery cells (108) electrically coupled to a first battery module terminal and a second battery module terminal, wherein: the first battery module connection is electrically coupled in parallel with the first electrical connection of the first fuse (106A) and the first electrical connection of the second fuse (106B); the second electrical connection of the first fuse (106A) is electrically coupled to the first contactor connection of the first contactor (104A); the second electrical terminal of the second fuse (106B) is electrically coupled to the first contactor terminal of the second contactor (104B); and the second contactor terminal of the first contactor (104A) and the second contactor terminal of the second contactor (104B) are electrically coupled to each other; and a contactor control module (102), configured to: Maintaining a closed state of the first contactor (104A) and the second contactor (104B) in response to the detection of a current below a predetermined current level; Moving the first contactor (104A) to an open state while the second contactor (104B) remains in the closed state, in response to the detection of a current above the predetermined current level. [2] Battery system (100) according to claim 1, wherein the first contactor (104A) further comprises a first contactor control terminal and wherein the second contactor (104B) further comprises a second contactor control terminal, wherein the contactor control module (102) comprises: a first contactor control output that is electrically coupled to the first contactor control terminal; and a second contactor control output, which is electrically coupled to the second contactor control terminal. [3] Battery system (100) according to claim 2, wherein the contactor control module (102) is configured to: Setting at least one of an open state and a closed state of the first contactor (104A) via the first contactor control output; and Setting at least one of an open state and a closed state of the second contactor (104B) via the second contactor control output. [4] Battery system (100) according to claim 3, wherein the contactor control module (102) is further configured to open one of the first contactor (104A) and the second contactor (104B) based on the detection of a current within a predetermined current range. [5] Battery system (100) according to claim 4, wherein the predetermined current range is within the range of 2,400 amperes and 5,000 amperes. [6] Battery system (100) according to claim 3, wherein the contactor control module (102) is further configured to keep both the first contactor (104A) and the second contactor (104B) in the closed state based on the detection of a current greater than a predetermined current level. [7] Battery system (100) according to claim 6, wherein the predetermined current is at least 5,000 amperes. [8] Battery system (100) according to claim 2, wherein the battery system (100) is located in an electric vehicle. [9] Battery system (100) according to claim 8, wherein the contactor control module (102) is further configured to: Detecting a vehicle fault condition; and in response to the detection of the vehicle fault condition: Moving the first gate (104A) to the open state; and moving the second gate (104B) to the closed state, the electric vehicle operates in a reduced power mode when the vehicle fault condition is present. [10] Battery system (100) according to claim 1, wherein the first fuse (106A) and the second fuse (106B) each comprise a locally minimal cross-sectional area configured to melt at a predetermined current. [11] Battery system (100) according to claim 1, wherein the first battery module terminal is electrically coupled to a positive terminal of one or more battery cells. [12] Battery system (100) according to claim 1, further comprising: a busbar that provides switched current to an electric vehicle, wherein the busbar is electrically coupled in parallel to the second contactor terminal of the first contactor (104A) and the second contactor terminal of the second contactor (104B). [13] Battery system (100) according to claim 12, further comprising: a third contactor comprising a first contactor terminal and a second contactor terminal, wherein: the first contactor terminal of the third contactor is electrically coupled to the busbar; and The second contactor terminal of the third contactor is electrically coupled to a charging terminal. [14] Battery system (100) according to claim 1, further comprising: fourth and fifth contactors, each comprising a first contactor connection and a second contactor connection, wherein: the second battery module connection is electrically coupled in parallel with the first electrical connection of the first contactor (104A) and the first electrical connection of the second contactor (104B). [15] Battery system (100) according to claim 14, wherein the second battery module terminal is electrically coupled to a negative terminal of one or more battery cells. [16] Battery system (100) according to claim 14, further comprising: a busbar that provides switched current to an electric vehicle, wherein the busbar is electrically coupled. [17] Battery system (100) according to claim 16, further comprising: a sixth contactor comprising a first contactor terminal and a second contactor terminal, wherein: the first contactor terminal of the sixth contactor is electrically coupled to the busbar; and The second contactor connection of the sixth contactor is electrically coupled to a charging connection. [18] Battery system (100) according to claim 1, wherein the voltage across the first battery module terminal and the second battery module terminal is greater than 300 volts. [19] Battery system (100) according to claim 1, wherein the first and second battery module terminals each comprise non-switched terminals. [20] Battery system (100) according to claim 1, wherein the maximum operating current of the battery system (100) is between 1,000 A and 2,500 A.

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