RELAY MODULE FOR THE BATTERY SYSTEM OF A VEHICLE

Abstract

Relay module for a vehicle battery system, with: a movable unit (5) configured to move through a magnetic field of a coil (1) and a return spring (3) in the relay and to control the state of the electrical connection between the relay electrodes (11); and a microsensor (9) installed between the movable unit (5) and a stationary unit (7), wherein the microsensor (9) maintains a fixed position relative to the movable unit (5) and is configured to induce a change in an electrical physical quantity in response to a change in position of the movable unit (5) relative to the stationary unit (7); wherein the microsensor (9) comprises: a measuring unit (17) including two sensor electrodes (13) spaced apart by a predetermined distance so that the electrical resistance therebetween can be measured, and a sensor contact element (15) configured such that, when the movable unit (5) is moved in a direction in which the relay electrodes (11) can be electrically connected to each other, it moves in the same direction as the movable unit (5), thereby electrically connecting the two sensor electrodes (13) to each other; and a reference unit (23) including two reference electrodes (19) spaced a predetermined distance apart to allow measurement of the electrical resistance therebetween, and a functional unit (21) configured to move in the same direction as the movable unit (5) when the movable unit (5) is moved in a direction in which the relay electrodes (11) can be electrically connected to one another, and to be connected to the measuring unit (17).

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention

[0001] The present invention relates generally to a relay module for a vehicle battery system, and more particularly to a technology for a relay module that forms part of a power relay assembly in a battery system installed in a vehicle to provide a voltage used to power a vehicle such as a hybrid vehicle or an electronic vehicle, referred to herein as environmentally friendly vehicles. 2. Description of related technology

[0002] A battery system installed in an environmentally friendly vehicle is like Fig. 1, where a portion marked with a dashed line indicates a power relay assembly (PRA) 500. The purpose of such a PRA 500 is to ensure a high degree of electrical isolation and electrical safety between the vehicle systems and also to prevent the occurrence of serious secondary accidents such as high-voltage electric shock or fire due to electrical malfunction in an accident. The PRA 500 can also be used to block dark current from a high-voltage battery.

[0003] The power relay assembly 500 described above is configured to include a positive (+) main relay 502, a negative (-) main relay 504, and an initialization charge relay 506. Relay ON sequence control is performed as follows: when the vehicle enters the ignition ON state, the negative main relay 504 is turned on, followed by the initialization charge relay 506, which can limit a peak current caused by a resistor. After the positive main relay 502 is turned on, when the capacitor charging is complete, the initialization charge relay 506 is turned off, thus ending the relay ON sequence control. Thereafter, relay OFF sequence control is performed such that when the vehicle enters the ignition OFF state, in which the initialization charge relay 506 is turned off, the positive main relay 502 and the negative main relay 504 are turned off simultaneously.

[0004] To diagnose faults such as relay welding during the operation described above, in a battery management system (BMS), diagnosis has been performed indirectly using logic based on an operation sequence in which each relay operated as described above is used. Such a diagnosis based on such logic is disadvantageous in that, when the vehicle is started, only faults such as relay welding and an open circuit fault of the initialization charging relay 506 can be diagnosed. Therefore, when a problem occurs when the relay ON sequence is activated, it is difficult to determine whether the problem is caused by the relay itself, a fault in the internal control circuit of the BMS, or a disconnection or short circuit of an output-side conductor.Even if it is further determined that the problem is due to the relay itself, it is impossible to determine exactly whether the problem is caused by welding of the contact point of the relay or by a fault in the open state or where the problem lies (ie, in the positive main relay 502, the negative main relay 504, or the initialization charging relay 506).

[0005] Therefore, problems arise in that if a fault occurs in a relay included in the power relay assembly 500, immediate and accurate diagnosis of the problem is impossible. Furthermore, if only a specific relay is replaced based on a relay fault, there is a possibility that the actual faulty relay may not have been replaced, exposing the vehicle to an unexpectedly dangerous situation. Furthermore, when testing a vehicle, the work efficiency of troubleshooting is significantly reduced because the relay and a BMS must be replaced individually and then subjected to fault testing, resulting in a loss of time and increased costs.

[0006] The above statements in this background section serve only to better understand the background of the present invention and may therefore contain information that is not part of the prior art already known to those skilled in the art in this country.

[0007] EP 0 726 584 B1 describes a device for controlling an electromagnet, which is intended for an electromagnet with a stationary core, with a pickup winding through which current flows temporarily after switching on, with a holding winding through which current flows in the operating state, and with an armature that is movable relative to the core. A magnetically influenceable switching device connected in series with the pickup winding (1) contains a sensor coil having at least one turn and coupled to at least part of the magnetic field of the electromagnet, at least when the air gap is open. The voltage peak induced in the sensor coil at the moment the air gap closes switches a controllable semiconductor connected in series with the pickup winding to a high impedance via an electronic switching arrangement. The pickup winding is thus de-energized at the moment the air gap closes.The magnetically influenced switching device exploits the fact that a sharp change in the magnetic flux occurs in an electromagnet at the moment the air gap closes. The switching device is insensitive to external magnetic fields.

[0008] US 2014 / 0 002 092 A1 discloses an electromagnetic opening / closing device comprising a measuring part that measures a change associated with the opening / closing of a contact, a lifetime determination part that determines a state of the contact based on the change measured by the measuring part, and an output part that outputs the result determined by the lifetime determination part to the outside. Accordingly, a device equipped with the electromagnetic opening / closing device must

[0009] US 2011 / 0 266 129 A1 describes an electrical contact which comprises a core body made of elastic material with outer, inner and side surfaces, a metal mesh layer extending over the outer and side surfaces of the core body, and an adhesive layer covering the edge of the metal mesh layer on the side surface of the core body.

[0010] US 2007 / 0 087 266 A1 discloses a modular battery system having at least one set of battery modules connected in series. Each of the battery modules may be provided with a first end plate and a second end plate, each battery module being arranged between the first and second end plates, and at least one strap element connecting the end plates to each other and securing the battery module between the end plates. The end plates are mounted between a pair of rails, and the system is arranged in a system housing. A battery monitoring system, which may include a battery control module and at least one remote sensing module, preferably monitors and collects performance and status information, such as voltage and temperature, of the battery modules. An integrated control unit (ICU) may be arranged in the system housing.The ICU carries electronics, some of which are used to collect the electrical energy generated by the battery modules and / or to monitor the system. SUMMARY OF THE INVENTION

[0011] The present invention was therefore conceived in view of the above problems in the prior art. An object of the present invention is to provide a relay module for a vehicle battery system that directly, accurately, and immediately detects a fault in a relay constituting a component of a power relay assembly when the relay fault / problem / failure occurs, so that cost and time can be significantly reduced by improving the work efficiency of troubleshooting. Furthermore, unexpected dangerous situations for the vehicle can be prevented by improving the reliability of troubleshooting.The present invention can also monitor the states of the respective relays in real time, so that fault diagnosis is improved because it can be determined whether the fault is due to a failure of a relay itself, a relay control circuit in the BMS, or a short circuit or disconnection of an output-side conductor of the control circuit, thereby ensuring the safety of a vehicle system.

[0012] To achieve the above object, the present invention provides a relay module for a vehicle battery system having the features of claim 1 and a power relay assembly for a battery system having the features of claim 9. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The above and other objects, features and advantages of the present invention will become apparent from the following detailed description when taken in conjunction with the accompanying drawings, in which: Fig. 1 is a diagram of a conventional power relay assembly; Fig. 2 is a diagram of an exemplary configuration of a relay module for a vehicle battery system according to the present invention; Fig. 3 a diagram of an exemplary configuration of the microsensor of Fig. 2; Fig. 4 a diagram of an exemplary change in state of the microsensor when the relay module is switched on, compared to Fig. 3; and Fig. 5 is a diagram showing an exemplary concept of fault diagnosis using the relay module according to the present invention. DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0015] It is understood that the term "vehicle" or "vehicular" or other similar terms used herein generally refer to motor vehicles, such as passenger cars, including sports utility vehicles (SUVs), buses, trucks, various commercial vehicles, personal watercraft including various boats and ships, aircraft, and the like, and also includes hybrid vehicles, electric vehicles, plug-in hybrid electric vehicles (chargeable from a wall outlet), hydrogen-powered vehicles, and other alternative fuel vehicles (e.g., fuels derived from resources other than petroleum). As used herein, a hybrid vehicle is a vehicle with two or more power sources, e.g., vehicles with both gasoline and electric power.

[0016] As the Fig. As shown in Figures 2 to 4, one embodiment of the present invention includes a movable unit 5 configured to be moved by a magnetic field of a coil 1 and a return spring 3 in a relay and to control the state of electrical connection of the relay electrodes 11. A microsensor 9 is installed between the movable unit 5 and a stationary unit 7 to maintain a fixed position relative to the movable unit 5 and is configured to cause a change in electrical physical quantities (e.g., resistance, current, etc.) in response to a change in position of the movable unit 5 relative to the stationary unit 7.

[0017] The microsensor 9 can be extremely miniaturized and works in conjunction with the control function of the relay electrodes 11 and can be contained in or integrated into a conventional relay so that a fault of the corresponding relay can be directly detected in real time.

[0018] The microsensor 9 may include two sensor electrodes 13 spaced apart from each other by a predetermined distance so that electrical resistance between them can be measured, and a sensor contact element 15 configured so that when the movable unit 5 is moved in a direction in which the relay electrodes 11 can be electrically connected to each other, the sensor contact element 15 moves in the same direction as the movable unit 5, thereby electrically connecting the two sensor electrodes 13 to each other.

[0019] This means that the microsensor 9 can be configured so that when a voltage is applied to the coil 1, the movable unit 5 connects the relay electrodes 11, the sensor contact element 15 connects the two sensor electrodes 13, and the measured electrical resistance rapidly decreases, so that the normal ON function of the corresponding relay can be recognized by the normal functions of the movable unit 5 and the relay electrodes 11. On the other hand, when the voltage supply to the coil 1 is interrupted and the movable unit 5 blocks the relay electrodes 11, the sensor contact element 15 blocks the two sensor electrodes 13, whereupon the electrical resistance rapidly increases, so that the normal OFF function of the corresponding relay can be recognized by the normal functions of the movable unit 5 and the relay electrodes 11.

[0020] In the Fig. 3, the microsensor 9 includes a measuring unit 17 and a reference unit 23. The measuring unit 17 includes two sensor electrodes 13 spaced apart by a predetermined distance so that the electrical resistance therebetween can be measured, and a sensor contact element 15 configured so that when the movable unit 5 is moved in a direction in which the relay electrodes 11 can be electrically connected to each other, the sensor contact element 15 moves in the same direction as the movable unit 5, thereby electrically connecting the two sensor electrodes 13 to each other.The reference unit 23 includes two reference electrodes 19 spaced apart by a predetermined distance to allow the electrical resistance therebetween to be measured, and a functional unit 21 configured to move in the same direction as the movable unit 5 when the movable unit 5 is moved in a direction in which the relay electrodes 11 can be electrically connected to each other, while being connected to the measuring unit 17. In the embodiment of the present invention, the functional unit 21 may preferably consist only of an insulator that prevents electrical connection of the reference electrodes 19.

[0021] This means that the microsensor 9 can be implemented using only the measuring unit 17, but the reference unit 23 is additionally provided in parallel with the measuring unit 17 so that the state of the relay can be determined more accurately and reliably. The BMS should determine the state of the corresponding relay by taking into account both a change in the electrical resistance between the two sensor electrodes 13 of the measuring unit 17 and a change in the electrical resistance between the two reference electrodes 19 of the reference unit 23.

[0022] As described above, the measuring unit 17 operates in the same way as the microsensor 9, which is implemented only with the measuring unit 17, as described above. In contrast to the measuring unit 17, the reference unit 23 is characterized in that the functional unit 21 does not contain a sensor contact element 15 and consists only of a non-conductor. Even if the two sensor electrodes 13 of the measuring unit 17 are electrically connected to each other, as shown on the left side of Fig. 4, a high resistance value must therefore be detected between the two reference electrodes 19. Furthermore, even if the functional unit 21 has been moved a greater distance away from the two reference electrodes 19, as shown in Fig. 3, the resistance between the two reference electrodes 19 should not change.

[0023] That is, if there is a resistance change between the two sensor electrodes 13 of the measuring unit 17, it is determined that the corresponding relay is behaving normally only if the resistance between the two reference electrodes 19 of the reference unit 23 is continuously maintained at a constant value. Conversely, if the resistance between the reference electrodes 19 changes due to a disturbance or noise of the microsensor 9, it is determined that the relay is behaving abnormally.

[0024] The measuring unit 17 and the reference unit 23 can preferably be arranged side by side perpendicular to the direction of movement of the movable unit 5 and operate in parallel in conjunction with the movable unit 5.

[0025] The microsensor 9 can be manufactured from a flexible silicon-based material such as polydimethylsiloxane (PDMS) in a semiconductor manufacturing process. Preferably, the sensor electrodes 13 and the sensor contact element 15 of the measuring unit 17, as well as the reference electrodes 19 and the functional unit 21 of the reference unit 23, are individually sealed for safety guarantee, as shown in the drawings. Thus, the microsensor 9 is manufactured from a flexible silicon-based material in a semiconductor manufacturing process. The portion that causes a change in an electrical physical quantity is completely sealed as a completely sealed structure in a plasma process, thereby ensuring safety and reliability against the intrusion of foreign matter.

[0026] In the present embodiment, the movable unit 5 consists of a contact core 25, which is a conductor and is in direct contact with the relay electrodes 11, and a sliding core 27, which is integrally connected to the contact core 25 and configured to slide along a linear path in the center of the coil 1. The microsensor 9 is installed between a fixed core 29 (part of the stationary unit 7) for guiding the movable unit 5 along the linear path in the center of the coil 1 and providing a fixed position relative to the sliding core 27, and the sliding core 27.

[0027] In some embodiments of the present invention, the microsensor 9 may be implemented as an ultrasonic or infrared sensor according to conventional technologies in addition to the contact sensor described above.

[0028] A power relay assembly for a battery system is configured to include a positive main relay, a negative main relay, and an initialization charge relay, each embodied as the relay module of the present invention having the above configuration. Fig. 5 is a schematic diagram of a configuration for testing each relay of the above power relay assembly. That is, the configuration for testing the relay may be such that the BMS 31 can monitor the resistance values ​​of the measuring unit 17 and the reference unit 23 of the microsensor 9 in real time. The BMS 31 may further receive an ignition ON / OFF signal from an engine control unit (ECU) 33 and supply voltage to the coil 1 of the relay or cut off the voltage supply. In this way, functional information can be provided to the ECU 33 via the BMS 31.

[0029] In the configuration described above, the BMS 31 not only supplies voltage to the coil 1 depending on the ignition ON / OFF state of the ECU, but also measures and compares the resistance values ​​of the microsensor 9 as described above, thus immediately and directly determining whether the corresponding relay is operating normally.

[0030] For example, when the ECU 33 sends an ignition ON signal, the BMS 31 diagnoses a fault by measuring changes in the electrical resistance values ​​between the sensor electrodes 13 and between the reference electrodes 19 of the positive main relay, the negative main relay, and the initialization charge relay while energizing the coil 1. For example, if a welding-related fault occurs in the positive main relay, the sensor electrodes 13 of the positive main relay will continuously exhibit excessively low resistance. The BMS 31 detects the low resistance and determines that the fault in the positive main relay is due to a welding-related fault. The BMS 31 then notifies the user of such a fault via a warning lamp or the like, so that appropriate measures such as repair can be taken.

[0031] As described above, the present invention can directly, accurately, and immediately identify a fault in each relay of a power relay assembly when the fault occurs in the relay, thus significantly reducing the cost and time required for troubleshooting by improving work efficiency. Furthermore, by improving the reliability of troubleshooting, the vehicle can be prevented from being exposed to unexpected dangerous situations. Furthermore, the present invention can monitor the status of each relay in real time, thus improving fault diagnosis by determining whether the fault lies in a relay itself, the relay control circuit in a BMS, or a short circuit or disconnection of the output-side conductor, thereby ensuring the safety of a vehicle system.

[0032] Although the preferred embodiments of the present invention have been disclosed for exemplary purposes, those skilled in the art will recognize that various modifications, additions, and substitutions are possible.

Claims

[1] Relay module for a vehicle battery system, comprising: a movable unit (5) configured to move through a magnetic field of a coil (1) and a return spring (3) in the relay and to control the state of the electrical connection between the relay electrodes (11); and a microsensor (9) installed between the movable unit (5) and a stationary unit (7), wherein the microsensor (9) maintains a fixed position relative to the movable unit (5) and is configured to induce a change in an electrical physical quantity in response to a change in position of the movable unit (5) relative to the stationary unit (7); wherein the microsensor (9) comprises: a measuring unit (17) including two sensor electrodes (13) spaced apart by a predetermined distance so that the electrical resistance therebetween can be measured, and a sensor contact element (15) configured so that, when the movable unit (5) is moved in a direction in which the relay electrodes (11) can be electrically connected to each other, it moves in the same direction as the movable unit (5), thereby electrically connecting the two sensor electrodes (13) to each other; and a reference unit (23) including two reference electrodes (19) spaced a predetermined distance apart to allow measurement of the electrical resistance therebetween, and a functional unit (21) configured to move in the same direction as the movable unit (5) when the movable unit (5) is moved in a direction in which the relay electrodes (11) can be electrically connected to one another, and to be connected to the measuring unit (17). [2] Relay module according to claim 1, wherein the functional unit (21) consists of a non-conductor which prevents an electrical connection of the reference electrodes (19). [3] Relay module according to claim 1, wherein the measuring unit (17) and the reference unit (23) are arranged side by side perpendicular to the direction of movement of the movable unit (5). [4] Relay module according to claim 1, wherein the microsensor (9) is made of a flexible silicon-based material and the sensor electrodes (13) and the sensor contact element (15) of the measuring unit (17) as well as the reference electrodes (19) and functional unit (21) of the reference unit (23) are individually sealed. [5] The relay module according to claim 1, wherein the microsensor (9) is made of a flexible silicon-based material, and a portion causing the change in the electrical physical quantity is sealed. [6] Relay module according to claim 1, wherein: the movable unit (5) includes a contact core (25) made of a conductor, which is in direct contact with the relay electrodes (11), and a sliding core (27) integrally connected to the contact core (25) and configured to slide along a linear path in the center of the coil (1), and the microsensor (9) is installed between a fixed core (29), which is the stationary unit (7), to guide the movable unit (5) along the linear path in the center of the coil (1) and to provide a fixed position relative to the sliding core (27). [7] Relay module according to claim 1, wherein the microsensor (9) is designed as an ultrasonic sensor. [8] Relay module according to claim 1, wherein the microsensor (9) is designed as an infrared sensor. [9] Power relay assembly for a battery system, comprising: a positive main relay, a negative main relay and an initialization charging relay, each implemented as the relay module in a circuit, each relay module containing: a movable unit (5) configured to move through a magnetic field of a coil (1) and a return spring (3) in the relay and to control the state of the electrical connection between the relay electrodes (11); and a microsensor (9) installed between the movable unit and a stationary unit (7), the microsensor (9) maintaining a fixed position relative to the movable unit (5) and being configured to induce a change in an electrical physical quantity in response to a change in position of the movable unit (5) relative to the stationary unit (7); the microsensor (9) comprising: a measuring unit (17) including two sensor electrodes (13) spaced apart by a predetermined distance so that the electrical resistance therebetween can be measured, and a sensor contact element (15) configured so that, when the movable unit (5) is moved in a direction in which the relay electrodes (11) can be electrically connected to each other, it moves in the same direction as the movable unit (5), thereby electrically connecting the two sensor electrodes (13) to each other; and a reference unit (23) including two reference electrodes (19) spaced a predetermined distance apart to allow measurement of the electrical resistance therebetween, and a functional unit (21) configured to move in the same direction as the movable unit (5) when the movable unit (5) is moved in a direction in which the relay electrodes (11) can be electrically connected to one another, and to be connected to the measuring unit (17). [10] Power relay assembly according to claim 9, wherein the functional unit (21) consists of a non-conductor which prevents the electrical connection of the reference electrodes (19). [11] Power relay assembly according to claim 9, wherein the measuring unit (17) and the reference unit (23) are arranged side by side perpendicular to the direction of movement of the movable unit (5). [12] Power relay assembly according to claim 9, wherein the microsensor (9) is made of a flexible silicon-based material and the sensor electrodes (13) and the sensor contact element (15) of the measuring unit (17) as well as the reference electrodes (19) and the functional unit (21) of the reference unit (23) are individually sealed. [13] The power relay assembly according to claim 9, wherein the microsensor (9) (9) is made of a flexible silicon-based material, and a portion causing the change in the electrical physical quantity is sealed. [14] Power relay assembly according to claim 9, wherein the movable unit (5) includes a contact core (25) made of a conductor and in direct contact with the relay electrodes (11), and a sliding core (27) integrally connected to the contact core (25) and configured to slide along a linear path in the center of the coil (1), and the microsensor (9) is installed between a fixed core (29) which is part of the stationary unit (7) to guide the movable unit (5) along the linear path in the center of the coil (1) and to provide a fixed position relative to the sliding core (27). [15] Power relay assembly according to claim 9, wherein the microsensor (9) is designed as an ultrasonic sensor. [16] Power relay assembly according to claim 9, wherein the microsensor (9) is designed as an infrared sensor.

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