Power unit

Abstract

To allow determination of presence / absence of welding of a relay even when a power unit is removed from an apparatus on which the power unit is loaded.SOLUTION: A battery unit 200 comprises: a connection part which can be electrically connected with an electrical apparatus at a loading destination; cells 208 which can supply power to the electrical apparatus; a relay CR1-1 which is switched to either of a conduction state for electrically connecting a power supply line between the connection part and the cells 208 or a cut-off state for electrically cutting off the power supply line; a first notification device 212 which operates so that its operational state can be recognized from the outside when supply of power is received; and a first supply source 214 which supplies power to the first notification device 212 when the first supply source 214 is connected with the first notification device 212 and the relay CR1-1 is in the conduction state.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present disclosure relates to a power supply device that is detachable from an electrical device. [Background technology]

[0002] Electric vehicles equipped with power supply devices configured with replaceable batteries, etc. are known. For example, Japanese Patent Application Laid-Open Publication No. 2022-034842 (Patent Document 1) discloses a replaceable power supply device in which a relay is provided on each of the positive and negative power supply lines between a connection part with the vehicle and the battery. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2022-034842 Summary of the Invention [Problem to be solved by the invention]

[0004] In the power supply device described above, it is necessary to make and break multiple relays to determine whether welding has occurred. However, if the determination of whether welding has occurred is performed on the device (e.g., on the electric vehicle side) in which the power supply device is installed, when the power supply device is removed from the device, the determination result is not linked to the removed power supply device, so it may be necessary to determine whether welding has occurred again at the new location. As a result, the number of times the relays operate may increase.

[0005] The present disclosure has been made to solve the above-mentioned problems, and its purpose is to provide a power supply device that can determine whether a relay is welded even when the power supply device is removed from the equipment in which it is installed. [Means for solving the problem]

[0006] A power supply device according to one aspect of the present disclosure includes a connection unit electrically connectable to an electrical device on which it is mounted, a power storage device capable of supplying power to the electrical device, a relay that switches between a conductive state that electrically connects a power line between the connection unit and the power storage device and a cut-off state that electrically cuts off the power line, an alarm device that operates when supplied with power so that the conductive state can be recognized from the outside, and a supply source connected to the alarm device and that supplies power to the alarm device when the relay is in a conductive state.

[0007] In this way, even if the power supply unit is removed from the electrical equipment in which it is installed and the relay is controlled to be in the cutoff state, if the alarm device is operating using power from the supply source in such a way that its operating state can be recognized from outside, it can be determined that the relay has welded. Therefore, even if the power supply unit is removed from the equipment in which it is installed, it can be determined with high accuracy whether the relay has welded.

[0008] In one embodiment, the alarm device and the power supply are connected to the power line in parallel with the relay, and when the relay is in a conducting state, the alarm device, the power supply and the relay form a closed circuit, supplying power from the power supply to the alarm device.

[0009] In this way, if the power supply unit is removed from the electrical equipment in which it is installed and the relay is controlled to be in a cut-off state, and the alarm device is operating using power from the supply source in a way that allows its operating state to be recognized from the outside, it can be determined that the relay is welded.

[0010] In yet another embodiment, the notification device includes a light emitting device that emits light when in a conductive state.

[0011] In this way, if the light emitting device is emitting light when the power supply device is removed from the equipment in which it is installed, it can be determined with high accuracy that the relay is welded.

[0012] In a further embodiment, the alarm device includes a sound generating device that generates a sound when in a conductive state.

[0013] In this way, if the power supply device is removed from the equipment in which it is installed and sound is being generated by the sound generating device, it can be determined with high accuracy that the relay is welded. [Effects of the Invention]

[0014] According to the present disclosure, it is possible to provide a power supply device that is capable of determining whether a relay is welded even when the power supply device is removed from the device in which it is installed. [Brief explanation of the drawings]

[0015] [Figure 1] FIG. 1 illustrates an example of the configuration of a battery exchange system. [Figure 2] FIG. 2 is a diagram illustrating an example of the configuration of a battery unit. [Figure 3] FIG. 2 is a diagram illustrating a connection relationship between a vehicle and a battery unit. [Figure 4] FIG. 1 is a diagram illustrating an example of the configuration of a power supply system of a vehicle. [Figure 5] 10 is a timing chart showing an example of a method for determining whether each relay is welded. [Figure 6] 10 is a timing chart showing another example of a method for determining whether each relay is welded. [Figure 7] 1 is a diagram illustrating an example of the configuration of a battery unit that is a power supply device according to an embodiment of the present invention. [Figure 8] FIG. 10 is a diagram illustrating an example of the configuration of a battery unit that is a power supply device according to a modified example. DETAILED DESCRIPTION OF THE INVENTION

[0016] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are designated by the same reference numerals, and description thereof will not be repeated.

[0017] An example of a battery exchange system including a power supply device according to this embodiment will be described below. Fig. 1 is a diagram showing an example of the configuration of a battery exchange system. As shown in Fig. 1, the battery exchange system 1 includes a vehicle 100, a charging rack 120, and a charging stand 130.

[0018] Vehicle 100 is configured so that multiple rectangular parallelepiped battery units, including battery unit 200, can be detachably mounted in storage space 101. Fig. 1 shows an example in which vehicle 100 is configured so that three battery units can be mounted, and a case in which one battery unit 200 is mounted is shown, but the upper limit of the number that can be mounted is not particularly limited to three. Vehicle 100 includes, for example, electrically powered vehicles such as electric vehicles and hybrid vehicles.

[0019] Charging rack 120 is configured to be able to mount a plurality of battery units. Fig. 1 shows an example in which the charging rack is configured to be able to mount nine battery units, and seven battery units including battery unit 200 are mounted.

[0020] The charging rack 120 charges at least one of the stored battery units using power supplied from the charging stand 130. The charging rack 120 may charge the stored battery units one by one in a predetermined order, may charge each or some of the stored battery units in parallel, or may charge a battery unit designated by the charging stand 130. The charging rack 120 may charge the stored battery unit when the battery unit is stored, or may charge the stored battery unit upon receiving a request from the charging stand 130 to start charging.

[0021] The charging stand 130 is configured to be able to supply power to the charging rack 120. The charging stand 130 may, for example, transmit to the charging rack 120 information specifying a battery unit to be charged among the multiple battery units stored in the charging rack 120.

[0022] 2 is a diagram showing an example of the configuration of the battery unit 200. As shown in FIG. 2, the battery unit 200 includes a relay circuit 202, a positive connector 204, a negative connector 206, a plurality of cells 208, a first alarm device 212, and a second alarm device 222.

[0023] The relay circuit 202 includes a relay CR1-1 connected to the positive power supply line and a relay CR1-2 connected to the negative power supply line.

[0024] The plurality of cells 208 are configured by connecting a predetermined number of cells 208 (22 in FIG. 2) in series. The cells 208 may be, for example, any rechargeable power storage device, and may be, for example, a nickel-metal hydride battery, or a secondary battery such as a lithium-ion battery having a liquid or solid electrolyte. Capacitors may be used instead of the cells 208.

[0025] The positive connector 204 and the negative connector 206 are configured to be connectable to connectors provided in the storage space 101 of the battery unit 200 of the vehicle 100. The positive connector 204 and the negative connector 206 correspond to connection parts that electrically connect the battery unit 200 to the vehicle 100, which is an electrical device on which the battery unit 200 is mounted. The detailed configurations of the first alarm device 212 and the second alarm device 222 will be described later.

[0026] The housing of the battery unit 200 shown in FIG. 2 is configured so as to be able to be housed in a storage space 101 for the battery unit 200 provided in the vehicle 100.

[0027] FIG. 3 is a diagram illustrating the connection relationship between the vehicle 100 and the battery unit 200. As shown in FIG. 3, storage sections 106, 108, and 110 are provided within the storage space 101 of the vehicle 100. The three battery units 200, 300, and 400 are stored in the storage sections 106, 108, and 110, respectively. Each of the storage sections 106, 108, and 110 is provided such that its longitudinal direction coincides with the left-right direction of the vehicle 100. The storage sections 106, 108, and 110 are arranged along the front-rear direction of the vehicle 100. One longitudinal end of the storage section 106 is provided with two connectors (not shown) that can be connected to the positive connector 204 and the negative connector 206 of the battery unit 200, respectively. The other longitudinal end of the storage section 106 is provided with an opening configured to allow the battery unit 200 to be inserted. For example, when battery unit 200 is inserted into the opening of storage section 106 with the surface on which positive connector 204 and negative connector 206 are provided as the leading edge, and the position is fixed by placing a lid on the opening, positive connector 204 and negative connector 206 are connected to the two connection connectors provided in storage section 106. When positive connector 204 and negative connector 206 are connected to the two connection connectors, contact points inside the connectors come into contact and become electrically conductive.

[0028] Storage sections 108, 110 have a structure similar to that of storage section 106, and detailed description thereof will not be repeated. When battery units 300, 400 are inserted into storage sections 108, 110, respectively, and their positions are fixed as described above, the connectors on vehicle 100 and the connectors on the battery units are connected and electrically conductive.

[0029] When the three battery units 200, 300, and 400 are stored in each of the storage sections 106, 108, and 110, the positive connector of battery unit 200 is electrically connected to the positive power line of the power supply system of the vehicle 100, and the negative connector of battery unit 200 is electrically connected to the positive connector of battery unit 300. Furthermore, the negative connector of battery unit 300 is electrically connected to the positive connector of battery unit 400, and the negative connector of battery unit 400 is electrically connected to the negative power line of the power supply system of the vehicle 100. As a result, the three battery units are connected in series and connected to the power supply system of the vehicle 100.

[0030] The power supply system of vehicle 100 includes a capacitor 102 included in a PCU (Power Control Unit) (not shown), an SMR (System Main Relay) 104, and voltage sensors 150, 152, 154, and 156.

[0031] The SMR 104 is composed of a relay provided on each of the positive and negative power supply lines. A pre-charge relay, which has a resistor element (not shown) connected in series to the relay, is further connected in parallel to the negative power supply line.

[0032] The voltage sensor 150 detects the voltage V0 across the capacitor 102. The voltage sensor 152 detects the voltage V1 across the terminals of the battery unit 200. The voltage sensor 154 detects the voltage V2 across the terminals of the battery unit 300. The voltage sensor 156 detects the voltage V3 across the terminals of the battery unit 400.

[0033] Fig. 4 is a diagram illustrating an example of the configuration of a power supply system of vehicle 100. As shown in Fig. 4, the power supply system further includes an ECU (Electronic Control Unit) 140. Using a PCU, ECU 140 converts a DC power supply formed by three battery units into AC power and supplies the AC power to a load (such as a motor generator) that operates on the AC power. Furthermore, ECU 140 outputs a control signal to SMR 104 to control the operation of SMR 104.

[0034] Furthermore, when the battery units 200, 300, and 400 are stored in the storage sections 106, 108, and 110, the various relays included in the battery units 200, 300, and 400 are connected to the ECU 140 via communication lines.

[0035] Therefore, ECU 140 outputs a control signal to each of relays CR1-1 and CR1-2 of battery unit 200 housed in storage section 106 to control the operation of relay CR1-1 and relay CR1-2. Furthermore, ECU 140 outputs a control signal to each of relays CR2-1 and CR2-2 connected to the positive power supply line of battery unit 300 housed in storage section 108 to control the operation of relay CR2-1 and relay CR2-2. Furthermore, ECU 140 outputs a control signal to relay CR3-1 connected to the positive power supply line of battery unit 400 housed in storage section 110 and relay CR3-2 connected to the negative power supply line of battery unit 400 to control relay CR3-1 and relay CR3-2.

[0036] Furthermore, voltage sensors 150, 152, 154, and 156 are connected to ECU 140. Therefore, ECU 140 acquires voltage V0 detected by voltage sensor 150, voltage V1 detected by voltage sensor 152, voltage V2 detected by voltage sensor 154, and voltage V3 detected by voltage sensor 156.

[0037] When ECU 140 receives a request to start the system, for example, when the start switch is operated while the system of vehicle 100 is stopped, it controls the operation of each relay so that SMR 104 and each relay of battery units 200, 300, 400 are in a conductive state, thereby starting the system.

[0038] Furthermore, when ECU 140 receives a request to stop the system, for example, when the start switch is operated while the system of vehicle 100 is running, it controls the operation of each relay of SMR 104 and battery units 200, 300, 400 so that each relay is in a cut-off state, thereby stopping the system.

[0039] Furthermore, for example, when the three mounted battery units 200, 300, 400 are charged using an external power source (for example, when a connector is connected to an inlet (not shown) of the vehicle 100), the ECU 140 controls each relay to be in a conductive state. Furthermore, for example, when the charging of the three mounted battery units 200, 300, 400 is completed, the ECU 140 controls each relay to be in a cut-off state.

[0040] In vehicle 100 configured as described above, there are cases where switching from a conductive state to a cut-off state cannot be performed if the contacts of any of the relays included in three battery units 200, 300, and 400 are welded. Therefore, ECU 140 can execute a determination process to determine whether each relay of three battery units 200, 300, and 400 is welded before switching each relay to the cut-off state, for example, when transitioning the system to a stopped state or when external charging is completed.

[0041] Specifically, ECU 140 changes the combination of the conductive and cut-off states of each relay of battery units 200, 300, and 400, and can determine whether each relay is welded or not depending on whether the detection results of voltage sensors 152, 154, and 156 correspond to the changed combination, or can determine whether each relay is welded or not depending on whether the detection results of voltage sensor 150 correspond to the changed combination.

[0042] Fig. 5 is a timing chart showing an example of a method for determining whether each relay is welded. LN1, LN3, and LN5 in Fig. 5 show the state changes (control history) of relays CR1-1, CR2-1, and CR3-1 provided on the positive power supply lines of battery units 200, 300, and 400, respectively. LN2, LN4, and LN6 in Fig. 5 show the state changes (control history) of relays CR1-2, CR2-2, and CR3-2 provided on the negative power supply lines of battery units 200, 300, and 400, respectively.

[0043] For example, assume that battery units 200, 300, and 400 are stored in storage sections 106, 108, and 110, the relays of battery units 200, 300, and 400 are in a conductive state (on state), and the system of vehicle 100 is in an activated state (a state in which vehicle 100 can be driven or a state in which battery units 200, 300, and 400 can be externally charged).

[0044] At time T(0), if a request to turn off each relay is received, for example, when external charging is completed or a request to transition the system to a stopped state is received, ECU 140 executes a welding determination process.

[0045] When the welding determination process is started, the ECU 140 causes the relays CR1-1, CR2-1, and CR3-1 of each battery unit 200, 300, and 400 to be all in an OFF state, as shown by LN1, LN3, and LN5 in FIG. 5, and also causes the relays CR1-2, CR2-2, and CR3-2 of each battery unit 200, 300, and 400 to be all in a ON state, as shown by LN2, LN4, and LN6 in FIG. 5.

[0046] Next, ECU 140 acquires voltages V1, V2, and V3 detected by voltage sensors 152, 154, and 156. For example, when any of the voltages detected by voltage sensors 152, 154, and 156 is equal to or greater than a threshold value (for example, a value lower than the lower limit voltage of the battery unit), ECU 140 determines that welding has occurred in the relay on the positive electrode side of the battery unit that is the detection target of the voltage sensor that detected the voltage equal to or greater than the threshold value.

[0047] On the other hand, if all of the voltages detected by voltage sensors 152, 154, 156 are smaller than the threshold value, ECU 140 determines that the relays on the positive electrode sides of battery units 200, 300, 400 are not welded.

[0048] At time T(1), if ECU 140 determines that no welding has occurred in any of the positive side relays CR1-1, CR2-1, and CR3-1, it controls the relays CR1-1, CR2-1, and CR3-1 of battery units 200, 300, and 400 to be all conductive, and controls the relays CR1-2, CR2-2, and CR3-2 to be all disconnected.

[0049] Next, ECU 140 acquires voltages V1, V2, and V3 detected by voltage sensors 152, 154, and 156. For example, when any of the voltages detected by voltage sensors 152, 154, and 156 is equal to or greater than a threshold value, ECU 140 determines that welding has occurred in the relay on the negative electrode side of the battery unit that is the detection target of the voltage sensor that detected the voltage equal to or greater than the threshold value.

[0050] On the other hand, if all of the voltages detected by voltage sensors 152, 154, 156 are smaller than the threshold value, ECU 140 determines that welding has not occurred in the relays on the negative pole sides of battery units 200, 300, 400.

[0051] At time T(2), if ECU 140 determines that no welding has occurred in any of the negative relays CR1-2, CR2-2, and CR3-2, it controls relays CR1-1, CR2-1, and CR3-1 to be in an OFF state, and maintains relays CR1-2, CR2-2, and CR3-2 in an OFF state, thereby bringing the system of vehicle 100 into a stopped state.

[0052] The method of determining whether or not a relay is welded is not limited to the method described with reference to FIG. 5, and ECU 140 can also determine whether or not each relay is welded by using the detection result of voltage sensor 150, for example.

[0053] Fig. 6 is a timing chart showing another example of a method for determining whether a battery is welded. LN7, LN9, and LN11 in Fig. 6 show the state changes of relays CR1-1, CR2-1, and CR3-1 of battery units 200, 300, and 400, respectively. LN8, LN10, and LN12 in Fig. 6 show the state changes of relays CR1-2, CR2-2, and CR3-2 of battery units 200, 300, and 400, respectively.

[0054] For example, it is assumed that battery units 200, 300, and 400 are stored in storage sections 106, 108, and 110, the relays of battery units 200, 300, and 400 are in a conductive state (on state), and the system of vehicle 100 is in an activated state.

[0055] At time T(3), for example, when a request to turn off each relay is received, ECU 140 executes the welding determination process.

[0056] When the welding determination process is executed, ECU 140 turns off only relay CR1-1 as shown by LN7 in FIG. 6, and maintains the other relays in a conductive state as shown by LN8 to LN12 in FIG.

[0057] Next, ECU 140 acquires voltage V0 detected by voltage sensor 150. If voltage V0 detected by voltage sensor 150 is equal to or greater than a threshold value, ECU 140 determines that welding has occurred in relay CR1-1. On the other hand, if voltage V0 is smaller than the threshold value, ECU 140 determines that welding has not occurred in relay CR1-1.

[0058] At time T(4), when ECU 140 determines that relay CR1-1 is not welded, it sets relay CR1-1 to the conductive state, sets relay CR1-2 to the cut-off state, and maintains the other relays in the conductive state.

[0059] When the acquired voltage V0 is equal to or greater than the threshold value, the ECU 140 determines that the relay CR1-2 is welded. On the other hand, when the voltage V0 is smaller than the threshold value, the ECU 140 determines that the relay CR1-2 is not welded.

[0060] At time T(5), when ECU 140 determines that relay CR1-2 is not welded, it brings relay CR1-2 into a conductive state, brings relay CR2-1 into a cut-off state, and maintains the other relays in a conductive state.

[0061] When the acquired voltage V0 is equal to or greater than the threshold value, the ECU 140 determines that the relay CR2-1 is welded. On the other hand, when the voltage V0 is smaller than the threshold value, the ECU 140 determines that the relay CR2-1 is not welded.

[0062] At time T(6), when ECU 140 determines that relay CR2-1 is not welded, it sets relay CR2-1 to the conductive state, sets relay CR2-2 to the cut-off state, and maintains the other relays in the conductive state.

[0063] When the acquired voltage V0 is equal to or greater than the threshold value, the ECU 140 determines that the relay CR2-2 is welded. On the other hand, when the voltage V0 is smaller than the threshold value, the ECU 140 determines that the relay CR2-2 is not welded.

[0064] At time T(7), when ECU 140 determines that relay CR2-2 is not welded, it sets relay CR2-2 to the conductive state, sets relay CR3-1 to the cut-off state, and maintains the other relays in the conductive state.

[0065] When the acquired voltage V0 is equal to or greater than the threshold value, the ECU 140 determines that the relay CR3-1 is welded. On the other hand, when the voltage V0 is smaller than the threshold value, the ECU 140 determines that the relay CR3-1 is not welded.

[0066] At time T(8), when ECU 140 determines that relay CR3-1 is not welded, it sets relay CR3-1 to the conductive state, sets relay CR3-2 to the cut-off state, and maintains the other relays in the conductive state.

[0067] When the acquired voltage V0 is equal to or greater than the threshold value, the ECU 140 determines that the relay CR3-2 is welded. On the other hand, when the voltage V0 is smaller than the threshold value, the ECU 140 determines that the relay CR3-2 is not welded.

[0068] At time T(9), when ECU 140 determines that welding has not occurred in relay CR3-2, it maintains relay CR3-2 in the cut-off state and cuts off the other relays.

[0069] The welding determination process described using Figures 5 and 6 has been described as being executed in ECU 140 when battery units 200, 300, 400 are mounted on vehicle 100 as an example, but it may also be executed using any CPU (Central Processing Unit) that is capable of controlling each relay of the battery units in charging rack 120 and charging stand 130 when stored in charging rack 120 and that is capable of acquiring the voltage of each battery unit.

[0070] However, in these welding determination processes, the relay to be determined for welding is once set to an OFF state, the presence or absence of welding is determined, and then the relay is controlled to be turned ON again, so the determination result for the most recent occurrence of welding may not be obtained. Furthermore, when a battery unit is removed from the vehicle 100, the determination result for the presence or absence of welding is not linked to the removed battery unit, so the presence or absence of welding may need to be determined again at the destination. As a result, the number of times the relay operates may increase.

[0071] Therefore, in this embodiment, the battery unit 200 further includes a first alarm device 212 that operates when supplied with power so that its operating state can be recognized from outside, and a first supply source 214 that is connected to the first alarm device 212 and supplies power to the first alarm device 212 when the relay CR1-1 is in a conductive state.

[0072] Fig. 7 is a diagram showing an example of the configuration of a battery unit 200, which is a power supply device according to this embodiment. As shown in Fig. 7, a first alarm device 212 is connected in parallel with a relay CR1-1 to a power supply line PL1 that connects the positive connector 204 and the cell 208. A first power supply 214 is connected in series to the first alarm device 212.

[0073] More specifically, the first alarm device 212 includes a light-emitting device configured using a light-emitting diode (LED) as a light-emitting element. A positive terminal of the first power supply 214 is connected to a node 218 on the power supply line PL1 between the positive connector 204 and the relay CR1-1. The first power supply is, for example, a DC power supply configured using various types of batteries or a capacitor. A negative terminal of the first power supply 214 is connected to one end of the first alarm device 212. The other end of the first alarm device 212 is connected to a node 219 on the power supply line PL1 between the relay CR1-1 and the cell 208.

[0074] Therefore, when relay CR1-1 is in a conductive state, a closed circuit is formed by relay CR1-1, first alarm device 212, and first power supply source 214, and power is supplied from first power supply source 214 to first alarm device 212. When power is supplied to first alarm device 212, the light-emitting element is turned on, making it possible to recognize the operating state from outside. On the other hand, when relay CR1-1 is in a cut-off state, the above-mentioned closed circuit is not formed, and therefore no power is supplied to first alarm device 212, and the light-emitting element is turned off.

[0075] Although the first notification device 212 has been described as an example of a light-emitting device configured with a light-emitting diode as a light-emitting element, the first notification device 212 is not particularly limited to the use of a light-emitting diode.

[0076] The battery unit 200 further includes a second alarm device 222 and a second supply source 224. The second alarm device 222 and the second supply source 224 have the same configuration as the first alarm device and the first supply source 214, except that they are connected in parallel to the relays CR1-2 via nodes 228 and 229 to the power supply line PL2 connecting the negative connector 206 and the cell 208. Therefore, detailed description thereof will not be repeated.

[0077] For example, when battery unit 200 having such a configuration is removed from vehicle 100 in a state in which relays CR1-1 and CR1-2 are controlled to be in an interrupted state, if relay CR1-1 is welded, a closed circuit is formed among first alarm device 212, first power supply source 214, and relay CR1-1. Therefore, power is supplied from first power supply source 214 to first alarm device 212, and a light-emitting element included in first alarm device 212 is turned on. This makes it possible to recognize from outside battery unit 200 that relay CR1-1 is welded.

[0078] On the other hand, if relay CR1-2 is welded, a closed circuit is formed among second alarm device 222, second power supply 224, and relay CR1-2. Therefore, power is supplied from second power supply 224 to second alarm device 222, and a light-emitting element included in second alarm device 222 is turned on. This allows the fact that relay CR1-2 is welded to be recognized from outside battery unit 200.

[0079] As described above, with battery unit 200, which is a power supply device according to the present embodiment, when battery unit 200 is removed from vehicle 100, which is the electrical equipment on which it is installed, and relays CR1-1 and CR1-2 are controlled to be in an interrupted state, if first alarm device 212 is turned on using power from first supply source 214, thereby operating so that its operating state can be recognized from the outside, it can be determined that relay CR1-1 is welded. Alternatively, when second alarm device 222 is turned on using power from second supply source 224, thereby operating so that its operating state can be recognized from the outside, it can be determined that relay CR1-1 is welded. Therefore, even when battery unit 200 is removed from the equipment on which it is installed, it can be accurately determined whether relay CR1-1 has welded. Furthermore, since it is possible to determine whether welding has occurred in any of relays CR1-1, CR1-2, CR2-1, CR2-2, CR3-1, and CR3-2 of battery units 200, 300, and 400 without performing the welding determination process using Figure 5 or Figure 6 described above, it is possible to suppress an increase in the number of relay operations. Therefore, it is possible to provide a power supply device that can determine whether a relay has welded even when the device is removed from which it is installed.

[0080] Modifications will be described below.

[0081] In the above embodiment, the first alarm device 212 is described as being in a lit state when welding has occurred in the relay CR1-1, but the operation is not particularly limited to a lit state as long as it allows the conduction of the relay CR1-1 to be recognized from the outside. For example, when welding has occurred in the relay CR1-1, the light-emitting element of the first alarm device 212 may be made to flash, or the light may be made to light up in a manner that changes the emitted color over time.

[0082] Furthermore, in the above embodiment, first alarm device 212 and second alarm device 222 have been described as having the same configuration, but, for example, first alarm device 212 and second alarm device 222 may notify of the occurrence of welding in different ways. For example, first alarm device 212 may be lit in a different color than second alarm device 222, or first alarm device 212 may include a light-emitting device and second alarm device 222 may include a sound-emitting device. In this way, it is possible to reliably identify the welded relay.

[0083] In the above embodiment, the first alarm device 212 and the second alarm device 222 each include a light-emitting device configured with a light-emitting diode as a light-emitting element, but the present invention is not limited to including a light-emitting device. For example, the alarm device may include a sound-emitting device such as a buzzer.

[0084] Fig. 8 is a diagram showing an example of the configuration of a battery unit 200, which is a power supply device according to a modified example. The battery unit 200 shown in Fig. 8 differs from the battery unit 200 shown in Fig. 7 in that it includes a third notification device 312 instead of the first notification device 212 and a fourth notification device 322 instead of the second notification device 222, but otherwise has the same configuration as the battery unit 200 shown in Fig. 7.

[0085] The third alarm device 312 includes a sound generating device such as a buzzer. The sound generating device may be any device that generates sound when supplied with DC power, and is not limited to a device that generates a buzzer sound. The sound generating device may also be a device that generates voice or the like. One end of the third alarm device 312 is connected to the negative terminal of the first power supply 214. The other end of the third alarm device 312 is connected to a node 219 on the power supply line PL1 between the relay CR1-1 and the cell 208.

[0086] Therefore, when relay CR1-1 is in a conductive state, a closed circuit is formed by relay CR1-1, third alarm device 312, and first power supply source 214, and power is supplied from first power supply source 214 to third alarm device 312. When power is supplied to third alarm device 312, the buzzer device emits a sound, making it possible to recognize the operating state from outside. On the other hand, when relay CR1-1 is in a cut-off state, the closed circuit described above is not formed, and therefore no power is supplied to third alarm device 312, and the buzzer device does not emit a sound.

[0087] Furthermore, fourth alarm device 322 in this modification has a similar configuration to third alarm device 312, except that fourth alarm device 322 is connected in parallel to relays CR1-2 via nodes 228 and 229 to power supply line PL2 together with second power supply 224. Therefore, detailed description thereof will not be repeated.

[0088] When battery unit 200 having such a configuration is removed from vehicle 100, for example, while relays CR1-1 and CR1-2 are controlled to be in an interrupted state, if relay CR1-1 is welded, a closed circuit is formed among third alarm device 312, first power supply source 214, and relay CR1-1. As a result, power is supplied from first power supply source 214 to third alarm device 312, causing a sound to be generated from the sound generation device included in third alarm device 312. This allows the fact that relay CR1-1 is welded to be recognized from outside battery unit 200.

[0089] On the other hand, if relay CR1-2 is welded, a closed circuit is formed among fourth alarm device 322, second power supply 224, and relay CR1-2. As a result, power is supplied from second power supply 224 to fourth alarm device 322, causing a sound to be generated from the sound generation device included in fourth alarm device 322. This allows the fact that relay CR1-2 is welded to be recognized from outside battery unit 200.

[0090] In this modified example, the third alarm device 312 is described as emitting a sound when relay CR1-1 is welded, but the manner in which the sound is emitted is not particularly limited as long as the operation allows the relay CR1-1 to be externally recognized as being in a conductive state. For example, when relay CR1-1 is welded, third alarm device 312 may emit a sound intermittently, or the sound may be emitted in a manner in which the tone or volume changes over time.

[0091] Furthermore, in this modification, the third alarm device 312 and the fourth alarm device 322 have been described as having the same configuration, but the third alarm device 312 and the fourth alarm device 322 may notify the occurrence of welding in different ways. For example, the third alarm device 312 may be different from the fourth alarm device 322 in terms of volume, tone, interval, and content of the sound. In this way, the welded relay can be identified reliably.

[0092] The above-described modifications may be implemented in whole or in part in appropriate combination.

[0093] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present invention is defined by the claims, not by the above description, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0094] 1 Battery exchange system, 100 Vehicle, 102 Capacitor, 106, 108, 110 Storage section, 120 Charging rack, 130 Charging stand, 140 ECU, 150, 152, 154, 156 Voltage sensor, 200, 300, 400 Battery unit, 202 Relay circuit, 204 Positive connector, 206 Negative connector, 208 Cell, 212 First alarm device, 214 First supply source, 218, 219, 228, 229 Node, 222 Second alarm device, 224 Second supply source, 312 Third alarm device, 322 Fourth alarm device.

Claims

1. a connection portion that can be electrically connected to an electrical device on which the device is mounted; a power storage device capable of supplying power to the electrical device; a relay that switches between a conductive state that electrically connects a power supply line between the connection unit and the power storage device and a cut-off state that electrically cuts off the power supply line; an alarm device that operates when power is supplied so that the conductive state can be recognized from outside; a power supply connected to the alarm device and configured to supply power to the alarm device when the relay is in the conductive state.

2. the alarm device and the supply source are connected in parallel with the relay to the power supply line; The power supply device according to claim 1 , wherein when the relay is in the conductive state, a closed circuit is formed by the alarm device, the power supply source, and the relay, and power is supplied from the power supply source to the alarm device.

3. The power supply device according to claim 1 , wherein the notification device includes a light emitting device that emits light when the power supply is in the conductive state.

4. The power supply device according to claim 1 , wherein the notification device includes a sound generating device that generates a sound when the power supply is in the conductive state.

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