Battery system

Abstract

A battery system capable of switching connection modes of battery modules while suppressing short circuit of a battery. A control unit (10) switches on and off of a series connection switch (S / C_A) to be turned on when first and second storage sections (21, 22) of a battery (2) are connected in series, and parallel connection switches (S / C_B, S / C_C) to be turned on when they are connected in parallel, and the control unit (10) includes a first control switch (52) to open and close a current path from a power supply (50) to the series connection switch and the like, the power supply (50) being capable of supplying an operating current to the series connection switch and the like, and a second control switch (53) capable of switching a first state in which the series connection switch is connected to an output of the first control switch and a second state in which the parallel connection switch is connected to the output of the first control switch.

Description

Technical Field

[0001] This invention relates to a battery system. Background Technology

[0002] In recent years, in order to ensure that more people have access to affordable, reliable and sustainable modern energy, research and development are underway to develop charging and power supply systems for mobile vehicles equipped with secondary batteries that can help improve energy efficiency.

[0003] Regarding the charging power supply in mobile vehicles equipped with rechargeable batteries, different charging equipment is available depending on the charging station. For example, there are two types of charging equipment: one that supports 400V and one that supports 800V. If the mobile vehicle only supports 400V charging equipment, it cannot enjoy the fast charging performance of 800V charging equipment.

[0004] When a mobile vehicle supports both 400V and 800V charging equipment, charging is typically performed by boosting the voltage to 800V using a 400V charging device, or by stepping the voltage down to 400V using an 800V charging device. However, using a charging voltage converter directly during charging degrades efficiency.

[0005] In this regard, there are also known mobile vehicles that, by switching the connection method of the battery module, can be charged by either a 400V-level charging device or an 800V-level charging device, even without using a voltage converter for charging (for example, Patent Documents 1 and 2).

[0006] In the battery of such a mobile vehicle, there is a series switch that is turned on when the battery modules are connected in series and turned off when the battery modules are connected in parallel, and a parallel switch that is turned on when the battery modules are connected in parallel and turned off when the battery modules are connected in series. By appropriately switching these switches, charging can be carried out efficiently even when the charging voltage is different.

[0007] Existing technical documents

[0008] Patent documents

[0009] Patent Document 1: Japanese Patent Application Publication No. 2024-79278

[0010] Patent Document 2: Japanese Patent Application Publication No. 2024-115039 Summary of the Invention

[0011] The problem that the invention aims to solve

[0012] However, if the parallel switch is unintentionally turned on when the battery modules are connected in series, or if the series switch is unintentionally turned on when the battery modules are connected in parallel, the battery may short-circuit.

[0013] This invention provides a battery system that can switch the connection mode of the battery module while suppressing battery short circuits, thereby enabling charging even under different charging voltages.

[0014] Methods for solving problems

[0015] One aspect of this invention relates to a battery system, wherein,

[0016] The battery system includes:

[0017] A storage battery includes a first storage section, a second storage section, and a connection switching circuit capable of switching between a series connection state where the first storage section and the second storage section are connected in series and a parallel connection state where the first storage section and the second storage section are connected in parallel; and

[0018] The control unit controls the connection switching circuit.

[0019] The connection switching circuit includes:

[0020] A series-connected switch capable of being electrically operated, which is in an ON state in the series connection state and in an OFF state in the parallel connection state; and

[0021] A electrically actuated switch for parallel connection, which is in an open state in the series connection state and in an on state in the parallel connection state.

[0022] The control unit includes:

[0023] A power source capable of supplying operating current to the series connection switch and the parallel connection switch for turning the series connection switch and the parallel connection switch on.

[0024] A first control switch, which opens and closes the current path from the power source to the series connection switch and the parallel connection switch; and

[0025] The second control switch is capable of switching between a first state in which the series connection switch is connected to the output of the first control switch and a second state in which the parallel connection switch is connected to the output of the first control switch.

[0026] Invention Effects

[0027] According to the present invention, the connection mode of the battery module can be switched while suppressing battery short circuit. Attached Figure Description

[0028] Figure 1 This is a diagram illustrating an example of a charging system equipped with a storage battery for illustrating embodiments of the present invention.

[0029] Figure 2 It means Figure 1 A diagram showing the series connection of the batteries.

[0030] Figure 3 It means Figure 1 A diagram showing the parallel connection of the batteries.

[0031] Figure 4 It means control Figure 1 A diagram of the control section of the battery connection switching circuit.

[0032] Figure 5 This is a diagram showing the structure of the control unit in a parallel connection state.

[0033] Figure 6 This is a diagram showing the structure of the control unit in a series connection configuration.

[0034] Figure 7 It means control Figure 1 A diagram showing another example of the control section of the battery connection switching circuit.

[0035] Figure 8 It is a detailed representation Figure 4 The diagram shows the control circuit of the control unit.

[0036] Explanation of reference numerals in the attached figures

[0037] 1. Charging System

[0038] 2. Storage battery

[0039] 3 Three-phase motor

[0040] 4 Auxiliary machines

[0041] 5 Inverters

[0042] 10. Control Department

[0043] 21 First Battery Storage Unit

[0044] 22 Second Battery Storage Unit

[0045] 50 First Power Supply

[0046] 51 Second Power Supply

[0047] 52 First control switch

[0048] 53 Second control switch

[0049] 54 Control Circuit

[0050] S / C_A Second Contactor

[0051] S / C_B Third Contactor

[0052] S / C_C Fourth Contactor. Detailed Implementation

[0053] An example of a charging system with a rechargeable battery, used to illustrate embodiments of the present invention, will be described based on the accompanying drawings.

[0054] Figure 1 The charging system 1 shown is installed in electric vehicles such as electric cars. The charging system 1 includes a battery 2, a three-phase motor 3, an auxiliary machine 4, an inverter 5 (INV), power supply circuits 11P and 11N, auxiliary machine drive circuits 12P and 12N, DC power supply circuits 13P and 13N, a branch circuit 14, and a control unit 10.

[0055] like Figures 1-3 As shown, the battery 2 includes a first energy storage unit 21, a second energy storage unit 22, first to fifth contactors M / C, S / C_A, S / C_B, S / C_C, P / C, a first resistor R1, a current sensor IS, and a current circuit breaker FUSE. The first energy storage unit 21 and the second energy storage unit 22 are battery modules capable of charging and discharging at 400V.

[0056] The first contactor M / C is located at the positive terminal of the battery 2 and functions as a main switch to connect and disconnect the battery 2 from the external (power supply circuit 11P).

[0057] The second to fourth contactors S / C_A, S / C_B, and S / C_C constitute a connection switching circuit that switches the connection state of the first energy storage unit 21 and the second energy storage unit 22 between series and parallel connections. The second contactor S / C_A is located at the midpoint of the series connection between the first energy storage unit 21 and the second energy storage unit 22. Furthermore, the third contactor S / C_B is connected in parallel with respect to the series circuit of the first energy storage unit 21 and the second contactor S / C_A, and the fourth contactor S / C_C is connected in parallel with respect to the series circuit of the second contactor S / C_A and the second energy storage unit 22.

[0058] like Figure 2As shown, when the second contactor S / C_A is set to the ON state and the third contactor S / C_B and the fourth contactor S / C_C are set to the OFF state, the battery 2 becomes a series connection state where the first energy storage unit 21 and the second energy storage unit 22 are connected in series (800V start-up), and can be charged and discharged at 800V. Additionally, as... Figure 3 As shown, when the second contactor S / C_A is set to the open state and the third contactor S / C_B and the fourth contactor S / C_C are set to the closed state, the battery 2 becomes a parallel connection state (400V starting) where the first energy storage unit 21 and the second energy storage unit 22 are connected in parallel, enabling charging and discharging at 400V. Furthermore, starting includes both driving the electric vehicle equipped with the charging system 1 while it is in motion and charging it when it is parked.

[0059] The fifth contactor P / C and the first resistor R1 are connected in series and in parallel with the first contactor M / C. In both the series and parallel connection states, the fifth contactor P / C is turned on before the first contactor M / C is turned on, thereby protecting the first contactor M / C from excessive inrush current.

[0060] The current sensor IS is disposed between the first contactor M / C and the first energy storage unit 21 and the second energy storage unit 22 to measure the current.

[0061] A current circuit breaker (FUSE) is disposed at the negative terminal of the battery 2, and disconnects the battery 2 from the external power supply circuit (11N) in the event of an abnormality. In the charging system 1 of this embodiment, the current circuit breaker (FUSE) is composed of a high-temperature fuse capable of actively cutting off the current according to an electrical signal. In the event of an abnormality (such as a vehicle collision or a short circuit in the battery 2), the current circuit breaker (FUSE) cuts off the current and disconnects (opens) all contactors in the battery 2.

[0062] The three-phase motor 3 has three-phase coils 32U, 32V, and 32W connected at one end to the neutral point 31, and is driven to rotate by power supplied from the battery 2 via the inverter 5. In this embodiment, the three-phase motor 3 has a U-phase terminal 33U, a V-phase terminal 33V, and a W-phase terminal 33W connected to the other end of the coils 32U, 32V, and 32W. The U-phase terminal 33U, V-phase terminal 33V, and W-phase terminal 33W are connected to the inverter 5. Furthermore, the other end of any one phase coil 32U, 32V, or 32W is connected to a branch circuit 14 at a connection portion 34. In this embodiment, coil 32U of the three-phase coils 32U, 32V, and 32W is connected to the branch circuit 14 at the connection portion 34 located between the U-phase terminal 33U and the inverter 5.

[0063] Inverter 5 converts the DC power supplied from battery 2 into three-phase AC power by switching multiple switching elements, thereby driving the three-phase motor 3 to rotate. In addition, when supplying DC current (400V) from branch circuit 14 to connection section 34, inverter 5 can function as a boost circuit (DC voltage conversion section) that uses the coil connected to branch circuit 14 and the coil of another phase or two other phases to boost the DC current by switching multiple switching elements.

[0064] Auxiliary unit 4 is an on-board device capable of being driven by DC power from battery 2 and an external power source, such as an electric compressor E-COMP for air conditioning (A / C), an electric heater ECH, and an auxiliary unit converter DC-CDC. The electric compressor E-COMP and the electric heater ECH are high-voltage driven on-board devices, and the auxiliary unit converter DC-CDC steps down the DC power from battery 2 and the external power source to drive low-voltage driven on-board devices. Auxiliary unit 4 is connected to battery 2 via auxiliary unit drive circuits 12P and 12N, the sixth contactor VS / C, and power supply circuits 11P and 11N. In this embodiment, auxiliary unit 4 operates with a base voltage of 800V while the vehicle is in motion. On the other hand, auxiliary unit 4 is configured to operate even if the voltage is not 800V, and is boosted to a highly efficient drive voltage when charged at 400V (described later).

[0065] The power supply circuits 11P and 11N consist of a positive and negative pair, connecting the battery 2 to the inverter 5 (three-phase motor 3). Connection portions 111P and 111N, connected to the DC power supply circuits 13P and 13N, are provided on the power supply circuits 11P and 111N. Connection portions 112P and 112N, connected to the auxiliary drive circuits 12P and 12N (auxiliary machine 4), are provided on the inverter 5 side of the power supply circuits 11P and 111N. Furthermore, a sixth contactor VS / C, which connects and disconnects the circuit between the connection portion 112P of the auxiliary drive circuit 12P and the connection portion 111P of the DC power supply circuit 13P, is provided on the positive side of the power supply circuit 11P. Additionally, a first voltage sensor V_PIN, a first smoothing capacitor C1, and a second resistor R2 are provided on the inverter 5 side of the power supply circuits 11P and 11N. The first voltage sensor V_PIN, the first smoothing capacitor C1, and the second resistor R2 are respectively disposed on the circuit connecting the power supply circuit 11P on the positive side and the power supply circuit 11N on the negative side. In addition, the second resistor R2 is provided to discharge the first smoothing capacitor C1 when the circuit is cut off.

[0066] The DC power supply circuits 13P and 13N consist of a positive and negative pair. One end of each circuit has a charging terminal 131P or 131N for connecting to an external power source such as a charging device. The other end is connected to the power supply circuits 11P and 111N via connecting portions 111P and 111N. A seventh contactor QC / C_A and an eighth contactor QC / C_B are provided on the DC power supply circuits 13P and 13N to switch the circuits on and off. A second voltage sensor V_BAT is located closer to the connecting portions 111P and 111N than the seventh contactor QC / C_A and the eighth contactor QC / C_B. A third voltage sensor V_QC is located closer to the charging terminals 131P and 131N than the seventh contactor QC / C_A and the eighth contactor QC / C_B.

[0067] Branch circuit 14 branches off in the DC power supply circuit 13P on the positive side, closer to the connection part 111P than the eighth contactor QC / C_A and the second voltage sensor V_BAT, and is connected to the coil of any one of the three-phase motors 3 via the connection part 34. A ninth contactor QC / C_C is provided in the middle of branch circuit 14 to turn the circuit on and off.

[0068] The control unit 10, for example, is the vehicle ECU, which controls the driving and charging of the charging system 1. More specifically, the control unit 10 performs on / off control of each contactor M / C, S / C_A, S / C_B, S / C_C, P / C, VS / C, QC / C_A, QC / C_B, and QC / C_C, as well as their adhesion detection and control of the inverter 5.

[0069] Figure 4 The control unit indicates the connection switching circuit that switches between the series connection state and the parallel connection state of battery 2.

[0070] The second contactor S / C_A, the third contactor S / C_B, and the fourth contactor S / C_C, which constitute the switching circuit, are all electrically actuated. They are turned on by being supplied with operating current and automatically turned off when the supply of operating current is cut off. Such contactors generally include a movable contact, a fixed contact, an electromagnet that magnetically attracts the movable contact towards the fixed contact, and a spring that applies force to the movable contact in the direction of moving the movable contact away from the fixed contact. By supplying operating current to the electromagnet, the movable contact, attracted by the electromagnet, contacts the fixed contact and becomes closed. When the supply of operating current is cut off, the movable contact, forceped by the spring, moves away from the fixed contact and becomes open.

[0071] The control unit 10 includes a first power supply 50 and a second power supply 51, a first control switch 52 and a second control switch 53, and a control circuit 54. The first power supply 50 supplies operating current to the second contactor S / C_A, the third contactor S / C_B, and the fourth contactor S / C_C. The first control switch 52 and the second control switch 53 are electrically actuated, and the second power supply 51 supplies operating current to the first control switch 52 and the second control switch 53. The first power supply 50 and the second power supply 51 can be the same power supply or different power supplies. The electrically actuated first control switch 52 and the second control switch 53 are, for example, relay switches.

[0072] The first control switch 52 opens and closes the current path from the first power supply 50 to the second contactor S / C_A, the third contactor S / C_B, and the fourth contactor S / C_C. The first control switch 52 includes a movable contact 60, a fixed contact 61, an electromagnet 62 that magnetically attracts the movable contact 60, and a spring (not shown) that applies a force to the movable contact 60 in the opposite direction to the attraction of the electromagnet 62. The movable contact 60 is electrically connected to the first power supply 50.

[0073] When the first control switch 52 is in the ON state, i.e., when operating current is supplied to the electromagnet 62 from the second power supply 51, the electromagnet 62 magnetically attracts the movable contact 60. The magnetically attracted movable contact 60 contacts the fixed contact 61, thus closing the current path from the first power supply 50 to the second contactor S / C_A, etc. When the first control switch 52 is in the OFF state, cutting off the supply of operating current to the electromagnet 62, the movable contact 60, which is spring-forced, moves away from the fixed contact 61, thus breaking the current path from the first power supply 50 to the second contactor S / C_A, etc.

[0074] The second control switch 53 is disposed between the first control switch 52 and the second contactor S / C_A, the third contactor S / C_B, and the fourth contactor S / C_C. The second control switch 53 can switch between a first state in which the second contactor S / C_A is connected to the output of the first control switch 52 and a second state in which the third contactor S / C_B and the fourth contactor S / C_C are connected to the output of the first control switch 52.

[0075] The second control switch 53 includes a movable contact 70, a first fixed contact 71, a second fixed contact 72, an electromagnet 73 that magnetically attracts the movable contact 70, and a spring (not shown) that applies force to the movable contact 70 in the opposite direction to the direction in which the electromagnet 73 attracts the movable contact 70. The movable contact 70 is electrically connected to a fixed contact 61, which is the output of the first control switch 52. The first fixed contact 71 is electrically connected to a second contactor S / C_A, and the second fixed contact 72 is electrically connected to a third contactor S / C_B and a fourth contactor S / C_C. The first fixed contact 71 and the second fixed contact 72 are spaced apart in the direction in which the electromagnet 73 attracts the movable contact 70, and the movable contact 70 is disposed between the first fixed contact 71 and the second fixed contact 72.

[0076] The control circuit 54 includes a first control terminal 80 and a second control terminal 81. The first control terminal 80 is electrically connected to one end of the coil of the electromagnet 62 of the first control switch 52, and the second control terminal 81 is electrically connected to one end of the coil of the electromagnet 73 of the second control switch 53. The first control terminal 80 is connected to ground inside the control circuit 54, thereby allowing current from the second power supply 51 to flow into the first control terminal 80 and supply operating current to the electromagnet 62 of the first control switch 52. Similarly, the second control terminal 81 is connected to ground inside the control circuit 54, thereby allowing current from the second power supply 51 to flow into the second control terminal 81 and supply operating current to the electromagnet 73 of the second control switch 53. The control circuit 54 is configured to control the connection between the first control terminal 80 and the ground wire, and the connection between the second control terminal 81 and the ground wire, according to the operating state of the electric vehicle, such as starting the battery 2 at 800V during driving or starting at 400V during charging.

[0077] Figure 5 This describes the circuit structure of the control unit 10 during 400V startup. Operating current is supplied from the second power supply 51 to the electromagnet 62 of the first control switch 52, putting the first control switch 52 in the ON state. Simultaneously, operating current is supplied from the second power supply 51 to the electromagnet 73 of the second control switch 53, also putting the second control switch 53 in the ON state. The electromagnet 73 magnetically attracts the movable contact 70, causing it to move away from the first fixed contact 71 and into contact with the second fixed contact 72.

[0078] A current path is established from the first power supply 50 to the third contactor S / C_B and the fourth contactor S / C_C, and operating current is supplied to the third contactor S / C_B and the fourth contactor S / C_C. On the other hand, the current path from the first power supply 50 to the second contactor S / C_A is interrupted, and the supply of operating current to the second contactor S / C_A is cut off. The second contactor S / C_A is in the open state, and the third contactor S / C_B and the fourth contactor S / C_C are in the closed state. The battery 2 becomes a 400V starting device with the first energy storage unit 21 and the second energy storage unit 22 connected in parallel.

[0079] Figure 6 This describes the circuit structure of the control unit 10 during 800V startup. Operating current is supplied from the second power supply 51 to the electromagnet 62 of the first control switch 52, putting the first control switch 52 in the ON state. Conversely, the supply of operating current from the second power supply 51 to the electromagnet 73 of the second control switch 53 is cut off, putting the second control switch 53 in the OFF state. The movable contact 70, released from the magnetic attraction by the electromagnet 73, moves away from the second fixed contact 72 and contacts the first fixed contact 71.

[0080] A current path is established from the first power supply 50 to the second contactor S / C_A, and operating current is supplied to the second contactor S / C_A. Conversely, the current path from the first power supply 50 to the third contactor S / C_B and the fourth contactor S / C_C is interrupted, and the supply of operating current to the third contactor S / C_B and the fourth contactor S / C_C is cut off. The second contactor S / C_A is in the ON state, and the third contactor S / C_B and the fourth contactor S / C_C are in the OFF state. The battery 2 then operates at 800V, with the first energy storage unit 21 and the second energy storage unit 22 connected in series.

[0081] In this way, the second control switch 53 exclusively establishes one of the current paths from the first power supply 50 to the second contactor S / C_A and from the first power supply 50 to the third contactor S / C_B and the fourth contactor S / C_C, and physically disconnects the other. This prevents the second contactor S / C_A, the third contactor S / C_B, and the fourth contactor S / C_C from being simultaneously in the ON state, thus preventing a short circuit in the battery 2.

[0082] When switching from 400V to 800V starting, or vice versa, the control circuit 54 first sets the first control switch 52 to the open state, disconnecting the current path from the first power supply 50 to the second contactor S / C_A, etc. In this state, the control circuit 54 switches the second control switch 53. Then, after the second control switch 53 has switched, the control circuit 54 sets the first control switch 52 to the closed state, closing the current path from the first power supply 50 to the second contactor S / C_A, etc., completing the switch from 400V to 800V starting, or vice versa.

[0083] With the current path from the first power supply 50 to the second contactor S / C_A, etc., disconnected, no voltage is applied between the movable contact 70 of the second control switch 53 and the first fixed contact 71 and the second fixed contact 72. By switching the second control switch 53 in this state, arcing between the contacts can be suppressed. Therefore, it is possible to prevent the movable contact 70 from sticking to the first fixed contact 71 or the second fixed contact 72, thus preventing the switching of the second control switch 53.

[0084] For example, the starting voltage is 800V during driving and 400V or 800V during charging. The second control switch 53 is preferably configured to establish a current path from the first power supply 50 to the second contactor S / C_A in the off state, and to establish current paths to the third contactor S / C_B and the fourth contactor S / C_C in the on state. That is, it is preferably set to 800V starting during driving in the off state and 400V starting in the on state. Thus, the output voltage of the battery 2 can be set to the driving voltage simply by activating the first control switch 52. Even if the signal to activate the second control switch 53 does not reach it, the second control switch 53 remains off and is set to 800V starting. Furthermore, even if the second control switch 53 is stuck in the off state, it is still set to 800V starting. Therefore, the electric vehicle can drive and charge, and the occupants of the electric vehicle can take measures such as moving to a safe location. On the other hand, if the second control switch 53 is stuck in the ON state, it is assumed that the vehicle is started at 400V and is parked in a safe place, either during or after charging, thereby ensuring the safety of the occupants.

[0085] In addition, it can also start at 400V while driving, and at either 400V or 800V while charging. In this case, such as Figure 7As shown, the second control switch 53 is preferably configured to establish a current path to the third contactor S / C_B and the fourth contactor S / C_C in the off state, and to establish a current path from the first power supply 50 to the second contactor S / C_A in the on state. That is, it is preferably set to start at 400V when driving in the off state and to start at 800V when on state.

[0086] The first control switch 52 is preferably configured to disconnect the current path from the first power supply 50 to the second contactor S / C_A, etc., in the open state, and close the current path from the first power supply 50 to the second contactor S / C_A, etc., in the closed state. Even if the first control switch 52 is stuck in the open state, the safety of the occupants can be ensured since it is assumed that the electric vehicle is parked in a safe place. When the first control switch 52 is stuck in the closed state, the electric vehicle can still be driven, and the occupants of the electric vehicle can take measures such as moving to a safe place.

[0087] Figure 8 This describes the details of the control circuit 54. The control circuit 54 includes a first control switch drive circuit 90, a second control switch drive circuit 91, a second contactor drive circuit 92, a third contactor drive circuit 93, a fourth contactor drive circuit 94, and a processor 95 that controls these drive circuits 90 to 94.

[0088] The first control switch drive circuit 90 includes: a first control terminal 80 electrically connected to one end of the coil of the electromagnet 62 of the first control switch 52; and a switching element capable of connecting the first control terminal 80 to ground. The switching element connects or disconnects the first control terminal 80 from ground according to a control signal input from the processor 95. As described above, by connecting the first control terminal 80 to ground, current flows from the second power supply 51 into the first control terminal 80, supplying operating current to the electromagnet 62 of the first control switch 52, thus turning on the first control switch 52.

[0089] The second control switch drive circuit 91 includes: a second control terminal 81 electrically connected to one end of the coil of the electromagnet 73 of the second control switch 53; and a switching element capable of connecting the second control terminal 81 to ground. The switching element connects or disconnects the second control terminal 81 from ground according to a control signal input from the processor 95. As described above, by connecting the second control terminal 81 to ground, current flows from the second power supply 51 into the second control terminal 81, supplying operating current to the electromagnet 73 of the second control switch 53, thus turning on the second control switch 53.

[0090] The second contactor drive circuit 92 is electrically connected to one end of the coil of the electromagnet 96 of the second contactor S / C_A. The second contactor drive circuit 92 includes a switching element capable of connecting the coil of the electromagnet 96 of the second contactor S / C_A to ground. The switching element connects or disconnects the coil from ground according to a control signal input from the processor 95. When the first control switch 52 is in the ON state and the second control switch 53 is in the OFF state, and operating current can be supplied to the electromagnet 96 of the second contactor S / C_A, one end of the coil of the electromagnet 96 of the second contactor S / C_A is connected to ground, thereby allowing current to flow from the first power supply 50 into the second contactor drive circuit 92, supplying operating current to the electromagnet 96 of the second contactor S / C_A, and turning on the second contactor S / C_A.

[0091] The third contactor drive circuit 93 is electrically connected to one end of the coil of the electromagnet 97 of the third contactor S / C_B. The third contactor drive circuit 93 includes a switching element capable of connecting the coil of the electromagnet 97 of the third contactor S / C_B to ground. The switching element connects or disconnects the coil from ground according to a control signal input from the processor 95. When the first control switch 52 and the second control switch 53 are in the ON state and the operating current can be supplied to the electromagnet 97 of the third contactor S / C_B, one end of the coil of the electromagnet 97 of the third contactor S / C_B is connected to ground, thereby allowing current to flow from the first power supply 50 into the third contactor drive circuit 93, supplying operating current to the electromagnet 97 of the third contactor S / C_B, and turning on the third contactor S / C_B.

[0092] The fourth contactor drive circuit 94 is electrically connected to one end of the coil of the electromagnet 98 of the fourth contactor S / C_C. The fourth contactor drive circuit 94 includes a switching element capable of connecting the coil of the electromagnet 98 of the fourth contactor S / C_C to ground. The switching element connects or disconnects the coil from ground according to a control signal input from the processor 95. When the first control switch 52 and the second control switch 53 are in the ON state and the operating current can be supplied to the electromagnet 98 of the fourth contactor S / C_C, one end of the coil of the electromagnet 98 of the fourth contactor S / C_C is connected to ground, thereby allowing current to flow from the first power supply 50 into the fourth contactor drive circuit 94, supplying operating current to the electromagnet 98 of the fourth contactor S / C_C, and turning on the fourth contactor S / C_C.

[0093] The first control switch drive circuit 90, the second control switch drive circuit 91, the second contactor drive circuit 92, the third contactor drive circuit 93, and the fourth contactor drive circuit 94 are independently configured. This allows for more reliable prevention of unintentional connection or setting changes to the switching circuits.

[0094] For example, suppose that when the first control switch 52 and the second control switch 53 are in the open state, an erroneous signal is input to the first control switch drive circuit 90, causing the first control switch 52 to unintentionally turn on. In this case, the first control switch 52 is in the closed state and the second control switch 53 is in the open state, and the operating current can be supplied to the electromagnet 96 of the second contactor S / C_A. However, whether the operating current is supplied to the electromagnet 96 of the second contactor S / C_A is controlled by the second contactor drive circuit 92. This avoids the connection of the switching circuit unintentionally starting at 800V.

[0095] Furthermore, assuming that when the first control switch 52 is in the ON state and the second control switch 53 is in the OFF state, an erroneous signal is input to the second control switch drive circuit 91, causing the second control switch 53 to unintentionally turn on. In this case, the first control switch 52 and the second control switch 53 are in the ON state, and the operating current can be supplied to the electromagnets 97 and 98 of the third contactor S / C_B and the fourth contactor S / C_C. However, whether the operating current is supplied to the electromagnets 97 and 98 of the third contactor S / C_B and the fourth contactor S / C_C is controlled by the third contactor drive circuit 93 and the fourth contactor drive circuit 94. This avoids the connection switching circuit from unintentionally switching from 800V start-up to 400V start-up.

[0096] The embodiments of the present invention have been described above, but the present invention is not limited to the above embodiments and can be appropriately modified and improved. At least the following matters are described in this specification. Furthermore, although corresponding constituent elements in the above embodiments are shown in parentheses, the invention is not limited thereto.

[0097] (1) A battery system, wherein,

[0098] The battery system includes:

[0099] A storage battery (battery 2) includes a first storage unit (first storage unit 21), a second storage unit (second storage unit 22), and a connection switching circuit capable of switching between a series connection state where the first storage unit and the second storage unit are connected in series and a parallel connection state where the first storage unit and the second storage unit are connected in parallel; and

[0100] The control unit (control unit 10) controls the connection switching circuit.

[0101] The connection switching circuit includes:

[0102] A series-connected switch (second contactor S / C_A) capable of being electrically operated, which is in the ON state in the series connection state and in the OFF state in the parallel connection state; and

[0103] The electrically actuated parallel connection switches (third contactor S / C_B and fourth contactor S / C_C) are in an open state in the series connection state and in an on state in the parallel connection state.

[0104] The control unit includes:

[0105] A power supply (first power supply 50) is capable of supplying operating current to the series connection switch and the parallel connection switch for turning the series connection switch and the parallel connection switch on.

[0106] A first control switch (first control switch 52) opens and closes the current path from the power source to the series connection switch and the parallel connection switch; and

[0107] The second control switch (second control switch 53) is capable of switching between a first state in which the series connection switch is connected to the output of the first control switch and a second state in which the parallel connection switch is connected to the output of the first control switch.

[0108] According to the battery system described in (1) above, the second control switch can establish one of the current paths from the power source to the series connection switch and the current path from the power source to the parallel connection switch, and disconnect the other. This prevents the series connection switch and the parallel connection switch from being simultaneously switched on, thus preventing a short circuit in the battery.

[0109] (2) According to the battery system in (1) above, wherein,

[0110] The first control switch and the second control switch are electrically actuated relay switches.

[0111] According to the battery system described in (2) above, the current path to be cut off can be physically cut off by the second control switch, and the battery can be reliably prevented from short-circuiting.

[0112] (3) The battery system according to (1) or (2) above, wherein,

[0113] The control unit further includes a control circuit (control circuit 54), which controls the opening and closing of the first control switch and the switching between the first state and the second state of the second control switch.

[0114] The control circuit switches the state of the second control switch when the first control switch is disconnected.

[0115] According to the battery system described in (3) above, when switching the state of the second control switch, it is possible to suppress the generation of electric arcs between the contacts of the second control switch. As a result, it is possible to suppress the sticking of the contacts of the second control switch and to prevent the situation where the second control switch cannot be switched.

[0116] (4) The battery system according to any one of (1) to (3) above, wherein,

[0117] The second control switch is in the first state when it is in the off state, and in the second state when it is in the on state.

[0118] According to the battery system described in (4) above, the safety of the occupants can be ensured in either the case where the second control switch is in the off state or in the case where it is in the on state.

[0119] (5) The battery system according to any one of (1) to (3) above, wherein,

[0120] The first control switch disconnects the current path when it is in the off state and closes the current path when it is in the on state.

[0121] According to the battery system described in (5) above, the safety of the occupants can be ensured in either the case where the first control switch is in the off state or in the case where it is in the on state.

[0122] (6) The battery system according to any one of (1) to (3) above, wherein,

[0123] The battery system supplies power to the vehicle's drive source (three-phase motor 3).

[0124] The battery outputs the operating voltage of the drive source in the series connection state.

[0125] The second control switch is in the first state when it is in the off state, and in the second state when it is in the on state.

[0126] According to the vehicle described in (6) above, the voltage output from the battery can be set to the operating voltage of the drive source, i.e., the vehicle's driving voltage, simply by operating the first control switch. Furthermore, the vehicle can still be driven even when the signal to turn on the second control switch is not received, or when the second control switch is stuck in the off state.

[0127] (7) The battery system according to any one of (1) to (3) above, wherein,

[0128] The battery system supplies power to the vehicle's drive source (three-phase motor 3).

[0129] The battery outputs the operating voltage of the drive source in the parallel connection state.

[0130] The second control switch is in the second state when it is in the off state, and in the first state when it is in the on state.

[0131] According to the battery system described in (7) above, the voltage output from the battery can be set to the operating voltage of the drive source, i.e., the vehicle's driving voltage, simply by operating the first control switch. Furthermore, the vehicle can still be driven even if the signal to turn on the second control switch does not reach the second control switch, or if the second control switch is stuck in the off state.

[0132] (8) The battery system according to (1) above, wherein,

[0133] The control unit also includes:

[0134] A first control switch driving circuit drives the first control switch.

[0135] The second control switch driving circuit drives the second control switch.

[0136] A series-connected switch drive circuit that drives the series-connected switch when it is able to supply the operating current to the series-connected switch; and

[0137] A parallel connection switch drive circuit drives the parallel connection switch when it is able to supply the operating current to the parallel connection switch.

[0138] The first control switch drive circuit, the second control switch drive circuit, the series connection switch drive circuit, and the parallel connection switch drive circuit are independent of each other.

[0139] According to the battery system described in (8) above, it is possible to more reliably prevent unintentional connection switching circuits and setting switching.

Claims

1. A battery system, wherein, The battery system includes: A storage battery includes a first storage section, a second storage section, and a connection switching circuit capable of switching between a series connection state where the first storage section and the second storage section are connected in series and a parallel connection state where the first storage section and the second storage section are connected in parallel; and The control unit controls the connection switching circuit. The connection switching circuit includes: A series-connected switch capable of being electrically operated, which is in an ON state in the series connection state and in an OFF state in the parallel connection state; and A electrically actuated switch for parallel connection, which is in an open state in the series connection state and in an on state in the parallel connection state. The control unit includes: A power source capable of supplying operating current to the series connection switch and the parallel connection switch for turning the series connection switch and the parallel connection switch on. A first control switch, which opens and closes the current path from the power source to the series connection switch and the parallel connection switch; and The second control switch is capable of switching between a first state in which the series connection switch is connected to the output of the first control switch and a second state in which the parallel connection switch is connected to the output of the first control switch.

2. The battery system according to claim 1, wherein, The first control switch and the second control switch are electrically actuated relay switches.

3. The battery system according to claim 1, wherein, The control unit further includes a control circuit that controls the opening and closing of the first control switch and the switching between the first and second states of the second control switch. The control circuit switches the state of the second control switch when the first control switch is disconnected.

4. The battery system according to any one of claims 1 to 3, wherein, The second control switch is in the first state when it is in the off state, and in the second state when it is in the on state.

5. The battery system according to any one of claims 1 to 3, wherein, The first control switch disconnects the current path when it is in the off state and closes the current path when it is in the on state.

6. The battery system according to any one of claims 1 to 3, wherein, The battery system supplies power to the vehicle's drive source. The battery outputs the operating voltage of the drive source in the series connection state. The second control switch is in the first state when it is in the off state, and in the second state when it is in the on state.

7. The battery system according to any one of claims 1 to 3, wherein, The battery system supplies power to the vehicle's drive source. The battery outputs the operating voltage of the drive source in the parallel connection state. The second control switch is in the second state when it is in the off state, and in the first state when it is in the on state.

8. The battery system according to claim 1, wherein, The control unit also includes: A first control switch driving circuit drives the first control switch. The second control switch driving circuit drives the second control switch. A series-connected switch drive circuit that drives the series-connected switch when it is able to supply the operating current to the series-connected switch; and A parallel connection switch drive circuit drives the parallel connection switch when it is able to supply the operating current to the parallel connection switch. The first control switch drive circuit, the second control switch drive circuit, the series connection switch drive circuit, and the parallel connection switch drive circuit are independent of each other.

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