Battery system capable of pack relay diagnosis and vehicle including the same

Abstract

The battery system may include a plurality of battery packs, a plurality of first relays connected between a positive electrode of a corresponding battery pack and a first contact for each of the plurality of packs, a plurality of second relays connected between a negative electrode of a corresponding battery pack and a second contact for each of the plurality of packs, a capacitor having both ends connected between a first wiring connected to the first contact and a second wiring connected to the second contact, a resistor and a switch connected in series between the first wiring and the second wiring, and a plurality of pack BMS (Battery Management System) that, after waking up, controls the plurality of first relays and the plurality of second relays to be closed and then determines that the plurality of first relays and the plurality of second relays are normal when a current flowing from the plurality of battery packs to the capacitor is detected.

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of priority based on Korean Patent Application No. 10-2022-0032752 dated March 16, 2022, and all contents disclosed in the documents of that Korean patent application are incorporated herein by reference.

[0002] The present disclosure relates to a battery system capable of pack relay diagnosis and a vehicle including the same. [Background technology]

[0003] The battery system may include a plurality of battery packs connected in parallel to a junction box. Power can be supplied from the plurality of battery packs to the vehicle through the junction box. As the number of the plurality of battery packs connected in parallel increases, the battery system can supply more power. Each of the plurality of battery packs includes a pack relay connected to the junction box and a pack battery management system (hereinafter, referred to as pack BMS) that controls the operation of the pack relay. When the relay of each of the plurality of battery packs is closed and the relay of the junction box is closed, power can be supplied from each battery pack to the vehicle.

[0004] After waking up, the pack BMS controls the pack relay to be closed. After that, the pack BMS determines whether the pack relay is normally closed. Hereinafter, the operation of determining whether the pack relay is normally closed is referred to as pack relay diagnosis.

[0005] Specifically, the pack BMS measures the voltages at both ends of the pack relays and compares the voltages at both ends to diagnose the pack relays. However, since one end of each of the multiple pack relays is connected to the junction box through one link bus bar, the voltage at one end of an unclosed pack relay among the multiple pack relays may be similar to the voltage of the battery pack. According to the conventional method for solving this problem, it takes a considerable amount of time to diagnose the pack relays.

[0006] Even when a pack relay diagnosis is performed on a plurality of pack relays one by one in sequence, it takes a considerable amount of time. Summary of the Invention [Problem to be solved by the invention]

[0007] An object of the present invention is to provide a battery system and a vehicle including the same that can reduce the time required for diagnosis of a plurality of pack relays. [Means for solving the problem]

[0008] According to one aspect of the invention, a battery system may include a plurality of battery packs, a plurality of first relays connected between a positive electrode of a corresponding battery pack and a first contact for each of the plurality of packs, a plurality of second relays connected between a negative electrode of a corresponding battery pack and a second contact for each of the plurality of packs, a capacitor having both ends connected between a first wiring connected to the first contact and a second wiring connected to the second contact, a resistor and a switch connected in series between the first wiring and the second wiring, and a plurality of pack BMS (Battery Management System) that, after waking up, controls the plurality of first relays and the plurality of second relays to be closed and then determines that the plurality of first relays and the plurality of second relays are normal when a current flowing from the plurality of battery packs to the capacitor is detected.

[0009] According to another aspect of the invention, a vehicle may include a battery system and a power device that is a load supplied with power from the battery system or that charges the battery system. The battery system may include a plurality of battery packs, a plurality of first relays connected between a positive electrode of a corresponding battery pack and a first contact for each of the plurality of packs, a plurality of second relays connected between a negative electrode of a corresponding battery pack and a second contact for each of the plurality of packs, a capacitor having both ends connected between a first wiring connected to the first contact and a second wiring connected to the second contact, a resistor and a switch connected in series between the first wiring and the second wiring, and a plurality of pack BMS (Battery Management System) that, after waking up, controls the plurality of first relays and the plurality of second relays to be closed and then determines that the plurality of first relays and the plurality of second relays are normal when a current flowing from the plurality of battery packs to the capacitor is detected.

[0010] The battery system may further include a plurality of current sensors for each of the plurality of battery packs, each of which senses a current flowing through a corresponding battery pack.

[0011] Each of the plurality of pack BMSs may receive a current sensing signal from a corresponding current sensor among the plurality of current sensors, and may diagnose at least one of the corresponding first and second relays as stuck open when the received current sensing signal indicates zero current.

[0012] The battery system may further include a main control IC that turns on the switch for a predetermined discharging period to discharge the capacitor when the battery system finishes operating.

[0013] The battery system may further include a first main relay connected between a first input terminal of a power device connected to the battery system and a positive electrode of the plurality of battery packs, and a second main relay connected between a second input terminal of the power device and a negative electrode of the plurality of battery packs. The capacitor, the resistor, and the switch may be located between the first main relay and the second main relay, and between the plurality of first relays and the plurality of second relays.

[0014] The first main relay and the second main relay may be controlled to an open state during a period in which a diagnosis is performed on the plurality of first relays and the plurality of second relays.

[0015] The battery system may further include a connection switch connected between one of the first wiring and the second wiring and the capacitor. Effect of the Invention

[0016] The present invention provides a battery system and a vehicle including the same that can reduce the time required for diagnosis of multiple pack relays. [Brief description of the drawings]

[0017] [Figure 1] FIG. 1 is a schematic diagram of a battery system and a vehicle including the same according to one embodiment. [Diagram 2] FIG. 2 is a flowchart illustrating a pack relay diagnosis method according to one embodiment. [Diagram 3] FIG. 3 is a schematic diagram of a battery system and a vehicle including the same according to another embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] Hereinafter, the embodiments disclosed in the present specification will be described in detail with reference to the accompanying drawings, and the same or similar components will be given the same or similar drawing numbers, and the repeated description thereof will be omitted. The suffixes "module" and / or "part" for components used in the following description are given or mixed for the sake of ease of specification writing only, and do not have any meaning or role that is different from each other. In addition, in describing the embodiments disclosed in the present specification, if it is determined that a detailed description of related publicly known technology may obscure the gist of the embodiments disclosed in the present specification, the detailed description thereof will be omitted. In addition, the accompanying drawings are only intended to facilitate understanding of the embodiments disclosed in the present specification, and the technical ideas disclosed in the present specification are not limited by the accompanying drawings, and it should be understood that the accompanying drawings include all modifications, equivalents, or alternatives included in the ideas and technical scope of the present invention.

[0019] Terms including ordinal numbers such as first, second, etc. may be used to describe various components, but the components are not limited to the terms. The terms are used only to distinguish one component from another.

[0020] When a component is referred to as being "coupled" or "connected" to another component, it should be understood that it may be directly coupled or connected to the other component, but that there may be other components in between. In contrast, when a component is referred to as being "directly coupled" or "directly connected" to another component, it should be understood that there are no other components in between.

[0021] In this application, terms such as "comprise" or "have" are intended to specify the presence of any feature, number, step, operation, component, part, or combination thereof set forth in the specification, but should be understood as not precluding the presence or additional possibility of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0022] FIG. 1 is a schematic diagram of a battery system and a vehicle including the battery system according to one embodiment.

[0023] The vehicle 3 includes a battery system 1 and a power device 2. In one embodiment, a vehicle is illustrated as an example of a device to which the battery system 1 is applied, but the present invention is not limited thereto. The vehicle 3 includes a hybrid car that is driven only by a motor without an internal combustion engine, or that includes both an internal combustion engine and a motor.

[0024] The battery system 1 includes a plurality of battery packs 10-30, a main control integrated circuit (IC) 40, and a junction device 50. Although the number of the plurality of battery packs is shown as three in FIG. 1, the invention is not limited thereto, and the battery system 1 may include four or more battery packs. In addition, although the plurality of battery packs 10-30 are shown connected in parallel in FIG. 1, two or more battery packs may be connected in series, and the plurality of battery packs connected in series may be connected in parallel.

[0025] The power device 2 may be a load that receives power from the battery system 1, or a charger for charging the battery system 1. For example, the power device 2 may include at least one of an inverter, a DC-DC converter, a motor, an electronic control circuit, an On Board Charger (OBC), and a fast charger of the vehicle 3. The power device 2 includes two input terminals IN1 and IN2.

[0026] The battery packs 10 to 30 are connected in parallel to one another, and both ends of each of the battery packs 10 to 30 are connected to the junction device 50 via lines 151 and 152.

[0027] The junction device 50 may include a first main relay 51 connected between the line 151 and an input terminal IN1 of the power device 2, and a second main relay 52 connected between the line 152 and an input terminal IN2 of the power device 2. The first and second main relays 51, 52 control connections between the plurality of battery packs 10 to 30 and the power device 2, and the main control IC 40 may generate a relay control signal MRS for controlling operations of the first and second main relays 51, 52 and transmit the relay control signal MRS to the junction device 50.

[0028] The junction device 50 can control the opening and closing of the first and second main relays 51, 52 by a relay control signal MRS. Although the junction device 50 is shown in FIG. 1 as including a pair of main relays, the number of main relay pairs may be determined depending on the number of power devices 2.

[0029] In one embodiment, the junction device 50 further includes a diagnostic circuit 53. The diagnostic circuit 53 includes a resistor 531, a switch 532, and a capacitor 533.

[0030] One end of the resistor 531 is connected to the wiring 151, and the other end of the resistor 531 is connected to one end of the switch 532, and the other end of the switch 532 is connected to the wiring 152. One end of the capacitor 533 is connected to the wiring 151, and the other end of the capacitor 533 is connected to the wiring 152. The switch 532 can be switched by a discharge signal DS transmitted from the main control IC 40. In the junction device 50, the diagnostic circuit 53 should be connected between the first main relay 51 and the second main relay 52 and the plurality of relays 101, 102, 201, 202, 301, 302. The main control IC 40 can control the first and second main relays 51, 52 to be in an open state during a pack relay diagnosis period for the plurality of relays 101, 102, 201, 202, 301, 302.

[0031] 1, the diagnostic circuit 53 can be realized as a separate component separated from the junction device 50. In this case, the diagnostic circuit 53 must also be connected between the junction device 50 and the plurality of relays 101, 102, 201, 202, 301, and 302.

[0032] The battery packs 10-30 include a plurality of battery cells 11-14, 21-24, 31-34, a plurality of pack battery management systems 100, 200, 300, a plurality of relays 101, 102, 201, 202, 301, 302, and a plurality of current sensors 103, 203, 303. The pack battery management system is hereinafter referred to as a pack BMS (Battery Management System). In FIG. 1, each of the battery packs 10-30 is shown to include four battery cells 11-14, 21-24, 31-34, but this is only an example, and the invention is not limited thereto. Also, each of the battery packs 10-30 is shown to include two relays, but this is only an example, and the number of relays may be at least one.

[0033] Each of the plurality of pack BMSs 100, 200, 300 is connected to a corresponding plurality of battery cells 11-14, 21-24, 31-34 and measures the cell voltages of the corresponding plurality of battery cells 11-14, 21-24, 31-34. Each of the plurality of pack BMSs 100, 200, 300 can obtain the voltage (hereinafter, battery pack voltage), current (hereinafter, battery pack current), and temperature (hereinafter, battery pack temperature) of the corresponding battery packs 10, 20, 30. Each of the plurality of pack BMSs 100, 200, 300 can control the charging and discharging of the battery packs 10-30 based on the cell voltages, battery pack currents, etc. of the corresponding plurality of battery cells 11-14, 21-24, 31-34 and can control and perform cell balancing operations for the corresponding plurality of battery cells 11-14, 21-24, 31-34.

[0034] The multiple pack BMS 100, 200, 300 can control the opening and closing of the multiple relays 101, 102, 201, 202, 301, 302 to control the charging and discharging of the multiple battery P packs 10 to 30. The relay 101 is connected between the positive electrode of the battery pack 10 and a contact (P+), and the relay 102 is connected between the negative electrode of the battery pack 10 and a contact (P-). The relay 201 is connected between the positive electrode of the battery pack 20 and a contact (P+), and the relay 202 is connected between the negative electrode of the battery pack 20 and a contact (P-). The relay 301 is connected between the positive electrode of the battery pack 30 and a contact (P+), and the relay 302 is connected between the negative electrode of the battery pack 30 and a contact (P-).

[0035] Each of the multiple pack BMSs 100, 200, 300 can generate two drive signals RLS1 / RLS2, RLS3 / RLS4, RLS5 / RLS6 to control the opening and closing of the corresponding two relays 101 / 102, 201 / 202, 301 / 302, and supply them to the corresponding two relays 101 / 102, 201 / 202, 301 / 302.

[0036] The main control IC 40 can receive information on the cell voltages of the battery cells 11-15, 21-25, 31-35, the battery pack voltages, the battery pack currents, and the battery pack temperatures of the battery packs 10, 20, 30 from the pack BMSs 100, 200, 300. The main control IC 40 can supply power control signals to the pack BMSs 100, 200, 300 to supply power to the outside, or can supply charge control signals to the pack BMSs 100, 200, 300 to charge the battery packs 10, 20, 30. In addition, the main control IC 40 performs control necessary for the operation of the battery system 1, and can start and control a protection operation when an abnormality in the battery system 1 is detected.

[0037] Each of the multiple current sensors 103, 203, 303 can measure the battery pack current and transmit a signal (hereinafter, a current sensing signal) IS1, IS2, IS3 indicating the measured current to each of the multiple pack BMSs 100, 200, 300.

[0038] FIG. 2 is a flowchart illustrating a pack relay diagnosis method according to one embodiment.

[0039] When the start of the vehicle 3 is turned on, the packs BMS 100, 200, 300 wake up (S1). After waking up, the packs BMS 100, 200, 300 can determine whether the relays 101 / 102, 201 / 202, 301 / 302 are normally closed.

[0040] After each of the multiple pack BMSs 100, 200, 300 wakes up, it controls the corresponding two relays 101 / 102, 201 / 202, 301 / 302 to be closed (S2).

[0041] Each of the multiple pack BMSs 100, 200, 300 can monitor the current sensing signals IS1, IS2, IS3 received from the corresponding current sensors 103, 203, 303 after controlling the corresponding two relays 101 / 102, 201 / 202, 301 / 302 to be closed (S3).

[0042] Each of the multiple pack BMSs 100, 200, 300 can determine whether the corresponding two relays 101 / 102, 201 / 202, 301 / 302 are normally closed based on the result of monitoring the corresponding current sensing signals IS1, IS2, IS3 (S4). During the period when each of the multiple pack BMSs 100, 200, 300 diagnoses the status of the corresponding two relays 101 / 102, 201 / 202, 301 / 302, the first and second main relays 51, 52 of the junction device 50 are in an open state.

[0043] If the two corresponding relays 101 / 102, 201 / 202, 301 / 302 are normally closed immediately after waking up, current will flow from the battery pack 10, 20, 30 to the capacitor 533, and the corresponding current sensor 103, 203, 303 can sense the current.

[0044] For example, the two relays 101 and 102 receive relay control signals RLS1 and RLS2 from the pack BMS 100 instructing them to be closed. When both of the two relays 101 and 102 are normally closed, a current flows from the battery pack 10 to the capacitor 533, and the current sensor 103 senses the current flowing through the capacitor 533 and generates a current sensing signal IS1. The current sensing signal IS1 is transmitted to the pack BMS 100, and the pack BMS 100 determines that both of the two relays 101 and 102 are normally closed based on the current sensing signal IS1. If at least one of the two relays 101 and 102 is in a stuck open state, at least one of the two relays 101 and 102 is not closed despite the closing control. Then, no current flows from the battery pack 10 to the capacitor 533. The pack BMS 100 can determine that at least one of the two relays 101, 102 is stuck open if the current sensing signal IS1 received from the current sensor 103 indicates zero current.

[0045] The two relays 201, 202 receive relay control signals RLS3, RLS4 from the pack BMS 200 instructing them to be closed. When both of the two relays 201, 202 are normally closed, a current flows from the battery pack 20 to the capacitor 533, and the current sensor 203 senses the current flowing through the capacitor 533 and generates a current sensing signal IS2. The current sensing signal IS2 is transmitted to the pack BMS 200, and the pack BMS 200 determines that both of the two relays 201, 202 are normally closed based on the current sensing signal IS2. If at least one of the two relays 201, 202 is in a stuck open state, at least one of the two relays 201, 202 is not closed despite the closing control. Then, no current flows from the battery pack 20 to the capacitor 533. The pack BMS 200 can determine that at least one of the two relays 201, 202 is stuck open if the current sensing signal IS2 received from the current sensor 203 indicates zero current.

[0046] The two relays 301, 302 receive relay control signals RLS3, RLS4 from the pack BMS 300 instructing them to be closed. When both of the two relays 301, 302 are normally closed, a current flows from the battery pack 30 to the capacitor 533, and the current sensor 303 senses the current flowing through the capacitor 533 and generates a current sensing signal IS3. The current sensing signal IS3 is transmitted to the pack BMS 300, and the pack BMS 300 determines that both of the two relays 301, 302 are normally closed based on the current sensing signal IS3. If at least one of the two relays 301, 302 is in a stuck open state, at least one of the two relays 301, 302 is not closed despite the closing control. Then, no current flows from the battery pack 30 to the capacitor 533. The pack BMS 300 can determine that at least one of the two relays 301, 302 is stuck open if the current sensing signal IS3 received from the current sensor 303 indicates zero current.

[0047] The multiple pack BMSs 100, 200, 300 can wake up at the same time as the operation of the battery system 1 starts. When the battery system 1 ends its operation, the main control IC 40 generates a discharge signal DS that turns on the switch 532 for a predetermined discharge period. Then, the capacitor 533 can be discharged through the resistor 531 and the switch 532. The predetermined discharge period can be set to a time sufficient for the capacitor 533 to be discharged to zero voltage. The battery system 1 can start its operation when the start of the vehicle 3 is turned on, and can end its operation when the start of the vehicle 3 is turned off. The operation of the battery system 1 may include a discharge operation that supplies power and a charge operation that is supplied with power.

[0048] When the diagnosis result for the two corresponding relays is stuck open, each of the plurality of pack BMSs 100, 200, 300 can inform the main control IC 40 of this. When any of the plurality of relays 101, 102, 201, 202, 301, 302 is stuck open, the main control IC 40 can maintain the first and second relays 51, 52 in an open state. When all of the plurality of relays 101, 102, 201, 202, 301, 302 are in a normal state, the main control IC 40 controls the first and second relays 51, 52 of the junction device 50 to be closed. The main control IC 40 can generate an off-level relay control signal MRS and transmit it to the junction device 50 in order to control the first and second main relays 51, 52 to be in an open state. The main control IC 40 can generate an on-level relay control signal MRS and transmit it to the junction device 50 in order to control the first and second main relays 51, 52 to a closed state.

[0049] Although FIG. 1 shows capacitor 533 as being directly coupled between wiring 151 and wiring 153, the invention is not so limited.

[0050] FIG. 3 is a schematic diagram of a battery system and a vehicle including the same according to another embodiment.

[0051] 3, the same components as those shown in FIG 1 will not be described. As shown in FIG 3, the diagnosis circuit 53 may further include a connection switch 534 connected between the capacitor 533 and one of the wiring 151 and the wiring 152. For example, the connection switch 534 may be connected between the capacitor 533 and the wiring 151. One end of the connection switch 534 is connected to the wiring 151, one end of the capacitor 533 is connected to the other end of the connection switch 534, and the other end of the capacitor 533 is connected to the wiring 152. The connection switch 534 may perform a switching operation in response to a switch control signal SCS.

[0052] The main control IC 40 may control the connection switch 534 to an on state during a diagnostic period for two relays corresponding to each of the multiple pack BMSs 100, 200, 300, and control the connection switch 534 to an off state when the diagnostic period ends. For this purpose, the main control IC 40 may further generate a switch control signal SCS. The main control IC 40 may generate an on-level switch control signal SCS during the diagnostic period, and generate an off-level switch control signal SCS when the diagnostic period ends. After the diagnostic period ends, the connection switch 534 is turned off, and the capacitor 533 may not be involved in the operation of the battery system 1 other than the diagnostic operation.

[0053] Although the embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements made by those having ordinary skill in the art to which the present invention pertains also fall within the scope of the present invention.

Claims

1. Multiple battery packs; a plurality of first relays, each of which is connected between a positive electrode of a corresponding battery pack and a first contact, for each of the plurality of battery packs; a plurality of second relays, each of which is connected between a negative terminal of a corresponding battery pack and a second contact, for each of the plurality of battery packs; a capacitor having both ends connected between a first wiring connected to the first contact and a second wiring connected to the second contact; a resistor and a switch connected in series between the first wiring and the second wiring; and a plurality of pack BMS (Battery Management System) that, after waking up, controls the plurality of first relays and the plurality of second relays to be closed, and then determines that the plurality of first relays and the plurality of second relays are normal when a current flowing from the plurality of battery packs to the capacitor is detected.

2. The battery system of claim 1 , further comprising a plurality of current sensors for each of the plurality of battery packs, the current sensors sensing a current flowing through a corresponding battery pack.

3. Each of the plurality of pack BMSs includes:

3. The battery system of claim 2, further comprising: a current sensing signal received from a corresponding current sensor among the plurality of current sensors; and when the received current sensing signal indicates zero current, diagnosing at least one of the corresponding first and second relays as stuck open.

4. 4. The battery system according to claim 1, further comprising a main control IC for turning on the switch for a predetermined discharging period to discharge the capacitor when the battery system finishes its operation.

5. a first main relay connected between a first input terminal of a power device connected to the battery system and a positive electrode of the plurality of battery packs; a second main relay connected between the second input terminal of the power device and the negative electrodes of the plurality of battery packs, The capacitor, the resistor, and the switch are a first main relay and a second main relay, and a second relay and a third relay are disposed between the first main relay and the second main relay, A battery system according to any one of claims 1 to 3.

6. The first main relay and the second main relay are The first relays and the second relays are controlled to be in an open state during a period in which a diagnosis is performed on the first relays and the second relays. The battery system of claim 5.

7. a connection switch connected between the capacitor and any one of the first wiring and the second wiring, A battery system according to any one of claims 1 to 3.

8. A battery system; A load that is powered by the battery system or includes a power device for charging the battery system; The battery system includes: Multiple battery packs; a plurality of first relays, each of which is connected between a positive electrode of a corresponding battery pack and a first contact, for each of the plurality of battery packs; a plurality of second relays, each of which is connected between a negative terminal of a corresponding battery pack and a second contact, for each of the plurality of battery packs; a capacitor having both ends connected between a first wiring connected to the first contact and a second wiring connected to the second contact; a resistor and a switch connected in series between the first wiring and the second wiring; and a plurality of pack BMSs for waking up, controlling the plurality of first relays and the plurality of second relays to be closed, and determining that the plurality of first relays and the plurality of second relays are normal when a current flowing from the plurality of battery packs to the capacitor is detected. vehicle.

9. The battery system includes: Further comprising a plurality of current sensors for detecting currents flowing through the corresponding battery packs, 9. The vehicle of claim 8.

10. Each of the plurality of pack BMSs includes: receiving a current sensing signal from a corresponding current sensor among the plurality of current sensors, and diagnosing at least one of the corresponding first and second relays as being stuck open when the received current sensing signal indicates zero current; 10. The vehicle of claim 9.

11. The battery system includes: and a main control IC for turning on the switch for a predetermined discharge period when the start of the vehicle is turned off, thereby discharging the capacitor. A vehicle according to any one of claims 8 to 10.

12. a first main relay connected between a first input terminal of the power device and positive electrodes of the plurality of battery packs; a second main relay connected between the second input terminal of the power device and the negative electrodes of the plurality of battery packs, The capacitor, the resistor, and the switch are The vehicle according to claim 8 , wherein a relay is disposed between the first main relay and the second main relay, and between the plurality of first relays and the plurality of second relays.

13. The battery system includes: controlling the first main relay and the second main relay to an open state during a period in which a diagnosis is performed on the plurality of first relays and the plurality of second relays; 13. A vehicle as claimed in claim 12.

14. The battery system includes: a connection switch connected between the capacitor and any one of the first wiring and the second wiring, A vehicle according to any one of claims 8 to 10.

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