JP6725440B2 - Battery system - Google Patents

Description

The present invention is a means for determining whether or not there is a problem that system main relays respectively provided on a positive electrode side power line and a negative electrode side power line that connect an assembled battery and an electric device are fixed in a closed state. And a battery system including.

In a battery system including an assembled battery in which a plurality of cells are connected in series and an electric device connected to the battery (for example, an inverter and a motor mounted in a hybrid vehicle), the assembled battery and the electric device are connected to each other. Alternatively, a system main relay is provided in each of the positive electrode line and the negative electrode line that connect the assembled battery and the electric device so that they can be disconnected. With this configuration, for example, when an abnormality occurs, the system main relay is opened to disconnect between the battery pack and the electric device to improve the safety of the system. ..

By the way, the moving current of the system main relay is welded to the fixed contact due to the large current flowing between the battery pack and the electric equipment, and the system main relay remains fixed in the closed state, and the system main relay is opened in the abnormal state. May not be possible. Therefore, it has been proposed to provide a means for determining whether or not the system main relay is stuck in the battery system provided with the system main relay.

For example, in Patent Document 1, a switch circuit and an operational amplifier circuit are provided, and welding of the system main relay is performed by the difference in voltage detected when the positive side (or negative side) system main relay is in a closed state or an open state, respectively. Detection techniques have been proposed.

JP, 2016-146280, A

However, conventionally, when the system main relay is welded, the output of the operational amplifier included in the operational amplifier circuit becomes a negative voltage with respect to the body ground (GND). In order to detect this voltage correctly, a power supply that outputs a negative voltage is required, which increases the cost.

An object of the present invention is to make it possible to detect welding of a system main relay without providing a power source that outputs a negative voltage.

A battery system according to the present invention includes an assembled battery including at least a first battery block and a second battery block connected in series, an electric device supplied with power from the assembled battery, and a positive electrode side of the first battery block. And a positive-side system main relay provided on the positive-side power line connecting the positive-side terminal of the electric device and a negative-side power line connecting the negative-side of the second battery block and the negative-side terminal of the electric device. And a negative side system main relay connected to the positive side and the negative side of each battery block without passing through each of the positive side and negative side system main relays. In a battery system of a vehicle, which includes a voltage detection circuit having a detection unit that detects a voltage of each of the battery blocks, a control device that controls ON/OFF of each system main relay and the insulation switch, When the respective system main relays are turned off and the respective insulation switches are set to a predetermined on/off state, the voltage of the first battery block or the second battery block corresponds to the predetermined on/off state. It is characterized in that at least one of the system main relays is determined to be abnormal when the threshold value is equal to or more than a set threshold value.

In the above invention, when the output of the battery pack is divided and the midpoint voltage is used as the body ground, the voltage detection circuit may detect the voltage with reference to the body ground.

Further, the control device, as a predetermined on-off state to be set in each of the insulation switch, only the insulation switch connected to one end side of the assembled battery, that is, the positive side or the negative side of the assembled battery among the insulation switches. It is better to turn it on.

That is, the control device connects the insulation switch connected to the negative side of the assembled battery when only the insulation switch connected to the positive side of the assembled battery of the insulation switches is turned on. When the detection value of the voltage detection circuit and only the insulation switch connected to the negative electrode side of the assembled battery among the insulation switches is turned on, the insulation switch connected to the positive electrode side of the assembled battery is The detection value of the voltage detection circuit to be connected, and, if both the acquired detection values are less than a predetermined threshold value is determined to be a failure of the system main relay, any of the acquired detection value is the When it exceeds a predetermined threshold value, it is determined that the insulation switch has failed.

According to the present invention, welding of the system main relay can be detected without providing a power source that outputs a negative voltage.

It is a circuit block diagram which shows one Embodiment of the battery system which concerns on this invention. FIG. 2 is a circuit diagram in which parts of the circuit shown in FIG. 1 other than a part contributing to a body GND potential are simplified. FIG. 5 is a diagram showing a combination of a SW pattern, an on/off state of an insulation switch in the SW pattern, a voltage detected in the SW pattern, and welding detection of a system main relay in the first embodiment. FIG. 3 is a circuit diagram showing an SW pattern and an ON/OFF state of a system main relay that operates normally in the first embodiment. FIG. 3 is a circuit diagram showing an SW pattern and an on/off state of a system main relay that does not operate normally in the first embodiment. FIG. 7 is a circuit diagram showing another ON/OFF state of the SW pattern and the system main relay that does not operate normally in the first embodiment. FIG. 5 is a diagram schematically showing the relationship between the SW pattern and the detected voltage in the first embodiment. 5 is a flowchart showing a welding detection process in the first embodiment. FIG. 7 is a circuit configuration diagram of a battery system in the second embodiment. FIG. 10 is a circuit diagram in which parts of the circuit shown in FIG. 9 other than those contributing to the body GND potential are simplified. FIG. 9 is a diagram showing a combination of a SW pattern, an on/off state of an insulation switch in the SW pattern, a voltage detected in the SW pattern, and welding detection of a system main relay in the second embodiment. FIG. 9 is a circuit diagram showing an on/off state of a SW pattern and a system main relay that operates normally in the second embodiment. FIG. 7 is a circuit diagram showing an on/off state of a SW pattern and a system main relay that does not operate normally in the second embodiment. FIG. 16 is a circuit diagram showing another ON/OFF state of the SW pattern and the system main relay that does not operate normally in the second embodiment. FIG. 16 is a circuit diagram showing another ON/OFF state of the SW pattern and the system main relay that does not operate normally in the second embodiment. FIG. 9 is a diagram schematically showing the relationship between SW patterns and detection voltages in the second embodiment. 7 is a flowchart showing a welding detection process in the second embodiment. FIG. 9 is a circuit configuration diagram of a battery system in the third embodiment. FIG. 16 is a diagram showing a combination of a SW pattern, an on/off state of an insulating switch in the SW pattern, a voltage detected in the SW pattern, and welding detection of a system main relay in the third embodiment. FIG. 16 is a diagram showing a main part of a circuit configuration of a battery system in a fourth embodiment. FIG. 16 is a circuit configuration diagram of a battery system in the fifth embodiment. 16 is a flowchart showing welding detection processing in the fifth embodiment. FIG. 27 is a diagram showing a combination of a SW pattern, an on/off state of an insulation switch in the SW pattern, a voltage detected in the SW pattern, and welding detection of a system main relay in the sixth embodiment. FIG. 27 is a circuit diagram showing an on/off state of a SW pattern, a system main relay that does not operate normally, and an insulation switch in the sixth embodiment. FIG. 27 is a circuit diagram showing another ON/OFF state of the SW pattern, the system main relay that does not operate normally, and the isolation switch in the sixth embodiment. FIG. 27 is a circuit diagram showing another ON/OFF state of the SW pattern, the system main relay that does not operate normally, and the isolation switch in the sixth embodiment. FIG. 19 is a diagram schematically showing the relationship between SW patterns and detection voltages in the sixth embodiment. 21 is a flowchart showing a welding detection process in the sixth embodiment. FIG. 28 is a diagram showing a combination of a SW pattern, an on/off state of an insulating switch in the SW pattern, a voltage detected in the SW pattern, and welding detection of a system main relay in the seventh embodiment. FIG. 20 is a diagram schematically showing the relationship between SW patterns and detection voltages in the seventh embodiment. 20 is a flowchart showing welding detection processing according to the seventh embodiment.

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

Embodiment 1.
FIG. 1 is a circuit configuration diagram showing an embodiment of a battery system according to the present invention. Note that components that are not used in the description of this embodiment are omitted from the drawings as appropriate. The battery system according to the present embodiment will be described by taking as an example the case where the battery system is installed in an electric vehicle (EV) or a plug-in hybrid vehicle (PHV) as a vehicle. FIG. 1 shows an assembled battery 1, an electric device 2, a booster circuit 3, a control device 4, and a voltage detection circuit 5.

The assembled battery 1 is configured by connecting a battery block B and a battery block G in series. In the case of the present embodiment, the battery block B corresponds to the first battery block and the battery block G corresponds to the second battery block. The battery blocks B and G are rechargeable secondary batteries, and various secondary batteries such as a lead storage battery, a nickel-cadmium storage battery, a nickel-hydrogen storage battery, and a lithium secondary battery can be used.

The electric device 2 includes, for example, an inverter and a motor that are connected to the assembled battery 1. The motor is a three-phase AC motor used to drive the vehicle. The inverter is a power converter that converts the DC power output from the battery pack 1 into three-phase AC power and applies it to the motor.

The assembled battery 1 and the inverter of the electric device 2 are a positive electrode side power line (positive electrode line) BL that connects the positive electrode of the assembled battery 1 and the positive electrode side terminal of the electric device 2 (inverter), and the negative electrode of the assembled battery 1 and the electricity. It is connected by a negative electrode side power line (negative electrode line) GL that connects to the negative electrode side terminal of the device 2 (inverter). The positive electrode line BL is provided with a system main relay SMR-B on the positive electrode side that opens and closes the positive electrode line BL. Further, the negative electrode line GL is provided with a system main relay SMR-G on the negative electrode side that opens and closes the negative electrode line GL.

The booster circuit 3 is provided between the system main relays SMR-B and SMR-G of the power lines BL and GL and the electric device 2, and boosts the voltage output from the assembled battery 1.

The control device 4 is configured as a logic circuit centered on a microcomputer. Specifically, a CPU (not shown) that executes a predetermined calculation and the like according to a preset control program, and a ROM (not shown) in which the control programs and control data necessary for the CPU to execute various calculation processes are stored in advance. Similarly, it is provided with a RAM (not shown) in which various data necessary for various arithmetic processing by the CPU are temporarily read and written, an input/output port (not shown) for inputting and outputting various signals, and the like. The control device 4 is realized by an ECU (Engine Control Unit), and in the case of the present embodiment, as one of the operation controls to be performed, the system main relays SMR-B, SMR-G and each of the insulation switches SW1 to SW4 described later. Control on and off.

The voltage detection circuit 5 is a circuit that detects the voltages of the battery blocks B and G included in the assembled battery 1. The voltage detection circuit 5 detects the voltage difference between the positive electrode side and the negative electrode side of each battery block B, G to detect the voltage of each battery block B, G, and a differential amplifier section 51 and a differential amplifier as detection means. An insulating switch section 52 for connecting or disconnecting the amplifier section 51 to or from each of the battery blocks B and G is provided. The differential amplifier 51 converts the detection voltage of each battery block B, G into 0 to 5 V which the control device 4 can recognize. The insulation switch unit 52 includes an insulation switch SW1 that connects or disconnects the positive electrode of the battery block B to the differential amplification unit 51, an insulation switch SW2 that connects or disconnects the negative electrode of the battery block B to the differential amplification unit 51, and a battery block G. An insulating switch SW3 for connecting or disconnecting the positive electrode of the battery block G to the differential amplifier 51 and an insulating switch SW4 for connecting or disconnecting the negative electrode of the battery block G to the differential amplifier 51 are included.

In the present embodiment, since the assembled battery 1 is composed of the battery blocks B and G, two sets of blocks are provided as the voltage detection system for the battery blocks B and G. Therefore, in the following description, the block BB on the positive side of the assembled battery 1 including the battery block B is referred to as “upper block”, and the block BG on the negative side of the assembled battery 1 including the battery block G is referred to as “lower block”. I will decide.

In the battery system according to the present embodiment, the VL sensor (not shown) provided between the system main relays SMR-B and SMR-G of the power lines BL and GL and the booster circuit 3 further detects VL voltage. In addition, resistors R5 and R6 for dividing the voltage between the power lines BL and GL are provided. Similarly, resistors R7 and R8 that divide the voltage between the power lines BL and GL for VH voltage detection by a VH sensor (not shown) provided between the booster circuit 3 of the power lines BL and GL and the electric device 2. Equipped with. The resistors R5 and R6 and the resistors R7 and R8 are connected to a body ground (hereinafter, “body GND”).

A characteristic of this embodiment is that the voltage detection circuit 5 is used as a welding detection circuit for the system main relays SMR-B and SMR-G. More specifically, when the system main relays SMR-B and SMR-G are turned off and the insulating switches SW1 to SW4 are set to a predetermined on/off state, the voltage of the battery block B or the battery block G is set to the predetermined voltage. At least one of the system main relays SMR-B and SMR-G is determined to be abnormal when the threshold value set for the on/off state is exceeded, that is, the welding of the system main relays SMR-B and SMR-G is detected. That's what I was able to do.

FIG. 2 is a circuit diagram in which parts of the circuit shown in FIG. 1 other than the part contributing to the potential VGND of the body GND are simplified. In FIG. 2, since the differential amplifier section 51 of the voltage detection circuit 5 is omitted, regarding the detection voltages VB and VG above and below each block, the inter-terminal voltages V1, V2, V3 and V4 on the input side are referred to. explain. The same applies to the following embodiments.

In the present embodiment, the voltage of the battery block B is 120V, the voltage of the battery block G is 80V, that is, the voltage of the assembled battery 1 is 200V. Further, the booster circuit 3 is assumed to be 0V when not operating. All the resistors R1 to R8 are set to 8 MΩ. Note that the offset voltage (for example, 0.77 V) of the differential amplifier 51 is added to the actual potential VGND of the body GND, but it can be ignored for the voltages of the battery blocks B and G. It is not taken into account in the calculations described. The same applies to the following embodiments.

FIG. 3 shows the SW pattern, the on/off states of the insulating switches SW1 to SW4 in the SW pattern, the voltage detected during the SW pattern, and the welding of the system main relays SMR-B and SMR-G in the present embodiment. It is a figure which shows the combination of detection. The circuit operation in the present embodiment will be described below with reference to FIG. As described above, the control device 4 performs on/off control of the system main relays SMR-B, SMR-G and the isolation switches SW1 to SW4.

In the present embodiment, in order to detect the voltages above and below the block, SW pattern 1, that is, all the insulating switches SW1 to SW4 are turned on to detect the voltages VB and VG. When the voltage is not detected, the SW pattern 2, that is, all the insulation switches SW1 to SW4 are turned off. The controller 4 thus operates the voltage detection circuit 5 for voltage detection.

Next, a circuit operation for detecting a defect that at least one of the system main relays SMR-B and SMR-G is welded and at least one of the power lines BL and GL is fixed in the closed state will be described.

In order to detect a malfunction, the control device 4 controls both the system main relays SMR-B and SMR-G to turn off, and turns on the SW pattern 3, that is, the insulation switch SW1, and at the same time, the other insulation switches SW2 to SW4. Turn off. The state of the circuit at this time is shown in FIG. Here, it is assumed that the system main relays SMR-B and SMR-G both operate normally and are in the open state. In addition, from the present embodiment to the fifth embodiment, it is assumed that the insulating switches SW1 to SW4 are turned on and off under the control of the control device 4.

In the following description, the resistors R1 to R8 are calculated as the same resistance value (8 MΩ), but different resistance values may be used as long as they are high resistance values, for example, mega order resistance values.

Here, since the isolation switch SW1 is on, the potential V1 of the plus terminal on the block becomes the battery potential 200V in the isolation switch SW1. Since the body GND is connected to the assembled battery 1 only through the insulation switch SW1, the potential VGND of the body GND becomes 200V, which is the same as the plus terminal on the block. Further, since the insulating switches SW2 to SW4 are off, the respective potentials V2 to V4 become 200V, which is the same as the potential VGND of the body GND.

As described above, since the potentials V1 and V2 of the terminals on the block are both 200V, the detection voltage VB on the block is V1 (200V)-V2 (200V)=0V. Similarly, since the potentials V3 and V4 of the terminals under the block are both 200V, the detection voltage VG under the block is V3 (200V)-V4 (200V)=0V. As in this example, when the system main relays SMR-B and SMR-G are not welded and are normally turned off under the control of the control device 4, when only the insulation switch SW1 is turned on, each block of the blocks is turned on. The detection voltages VB and VG are both 0V.

Here, similarly to the above, it is assumed that the control device 4 controls the system main relays SMR-B and SMR-G to be turned off, but the system main relay SMR-G remains in the closed state due to welding. The state of the circuit at this time is shown in FIG.

In this case, since the insulating switch SW1 is turned on, the potential V1 of the plus terminal on the block becomes 200V as in the above. On the other hand, the body GND is connected to the positive electrode side of the battery pack 1 through the insulation switch SW1, and at the same time, is connected to the negative electrode side of the battery pack 1 because the system main relay SMR-G is in the ON state. become. As a result, the potential VGND of the body GND becomes 67V, which is smaller than 200V, due to the connection relationship of the resistors R1 to R8. Since the isolation switch SW2 is off, the terminal of the isolation switch SW2 (minus terminal on the block) becomes 67V, which is the same as the potential VGND of the body GND. Since the isolation switches SW3, 4 under the block are off, the terminals of the isolation switches SW3, 4 are also 67V.

In this way, the potential V1 of the plus terminal on the block is 200V and the potential V2 of the minus terminal is 67V, so the detection voltage VB on the block is V1(200V)-V2(67V)=133V. The detection voltage VG under the block is V3(67V)-V4(67V)=0V.

As a result, the detected voltage VB on the block shows a voltage different from 0 V in the normal state, so that the welding of the system main relay SMR-G can be detected by referring to the detected voltage VB on the block. Since the detection voltage VG under the block shows 0 V, which is the same as in the normal state, the detection voltage VG under the block is not referred to for detecting the welding of the system main relay SMR-G.

Next, it is assumed that the control device 4 controls both the system main relays SMR-B and SMR-G to be turned off, but the system main relays SMR-B and SMR-G are both closed due to welding. The state of the circuit at this time is shown in FIG.

In this case, since the insulating switch SW1 is turned on, the potential V1 of the plus terminal on the block becomes 200V as in the above. On the other hand, the body GND is connected to the positive electrode side of the battery pack 1 via the insulation switch SW1 and the system main relay SMR-B, respectively, and is also connected to the negative electrode side of the battery pack 1 via the system main relay SMR-G. Will be. As a result, the potential VGND of the body GND becomes 120V, which is smaller than 200V, due to the connection relationship of the resistors R1 to R8. Since the isolation switch SW2 is off, the terminal of the isolation switch SW2 (minus terminal on the block) becomes 120 V, which is the same as the potential VGND of the body GND. Since the insulation switches SW3 and SW4 under the block are off, the terminals of the insulation switches SW3 and SW4 are also 120V.

In this way, the potential V1 of the plus terminal on the block is 200V and the potential V2 of the minus terminal is 120V, so the detection voltage VB on the block is V1 (200V)-V2 (120V)=80V. The detection voltage VG under the block is V3(120V)-V4(120V)=0V.

As a result, the detected voltage VB on the block shows a voltage different from 0 V at the normal time, so by referring to the detected voltage VB on the block, it is possible to detect the welding of both the system main relays SMR-B and SMR-G. .. Since the detection voltage VG under the block shows 0 V, which is the same as in the normal state, the detection voltage VG under the block is not referred to detect the welding of both the system main relays SMR-B and SMR-G.

In the above description, the welding of the system main relays SMR-B and SMR-G is detected by controlling only the SW pattern 3, that is, the insulation switch SW1 to be turned on. However, the SW pattern 4, that is, the insulation switch SW4 is detected. If the control is performed so that the other insulation switches SW1 to SW3 are turned off at the same time as turning on, the welding of the system main relays SMR-B and SMR-G can be detected in the same manner as above.

That is, the control device 4 controls both the system main relays SMR-B and SMR-G to be off, so that the system main relays SMR-B and SMR-G both operate normally and become in the open state. Since all V4 are 0V, the detection voltages VB and VG of each block are 0V.

Here, it is assumed that the control device 4 controls both the system main relays SMR-B and SMR-G to be turned off, but the system main relay SMR-B remains closed due to welding. In this case, the potential V4 of the minus terminal under the block becomes 0V as described above. On the other hand, the body GND is connected to the negative electrode side of the assembled battery 1 via the insulation switch SW4, and at the same time, connected to the positive electrode side of the assembled battery 1 because the system main relay SMR-B is in the ON state. become. As a result, the potential VGND of the body GND becomes 133V, which is larger than 0V, due to the connection relationship of the resistors R1 to R8, and thus the potentials V1 to V3 also become 133V. As a result, the detection voltage VG under the block becomes V3(133V)-V4(0V)=133V. The detection voltage VB on the block is V1(133V)-V2(133V)=0V.

Further, it is assumed that the control device 4 controls both the system main relays SMR-B and SMR-G to be turned off, but both the system main relays SMR-B and SMR-G remain closed due to welding. In this case as well, similarly to the above, the potential VGND of the body GND is 80 V, which is higher than 0 V due to the connection relationship of the resistors R1 to R8, and therefore the potentials V1 to V3 are also 80 V. As a result, the detection voltage VG under the block becomes V3(80V)-V4(0V)=80V. The detection voltage VB on the block is V1(80V)-V2(80V)=0V.

FIG. 7 is a diagram schematically showing the relationship between the SW patterns 1, 3, 4 and the detected voltage by the circuit operation described above. As shown in FIG. 7, in the present embodiment, a threshold value (Vth) is preset as a criterion for determining whether the system main relays SMR-B and SMR-G are normal or abnormal (welding). The threshold value may be set to an appropriate value with reference to the voltage of the assembled battery 1, the values of the resistors R1 to R8, and the like. In the case of this embodiment, a value of about 40 V may be set. It should be noted that different thresholds may be set above and below the block. The same applies to the following embodiments.

As is clear from FIGS. 7(a) and 7(b), if the system main relays SMR-B and SMR-G operate normally, the voltage will be 0V in any of the SW patterns 1, 3 and 4. .. Therefore, the insulation switches SW1 to SW4 are set to the SW pattern 3 to refer to the detection voltage on the block, or the insulation switches SW1 to SW4 are set to the SW pattern 4 to refer to the detection voltage under the block to detect each detection voltage. Is greater than the threshold value, it can be determined that the system main relays SMR-B and SMR-G are welded. In addition, in FIG. 7A, when the system main relay SMR-B is fixed, the detected voltage on the block is the same as in the normal operation of the system main relays SMR-B and SMR-G. It becomes 0V in 1, 3, and 4. Further, in FIG. 7B, when the system main relay SMR-G is fixed, the detected voltage under the block is the same as in the normal operation of the system main relays SMR-B and SMR-G in any SW pattern. It becomes 0V in 1, 3, and 4. Therefore, the line showing the normal operation overlaps with the drawing. The processing described above will be described with reference to the flowchart shown in FIG.

First, the control device 4 sets the insulation switches SW1 to SW4 to the SW pattern 3 (step 101) and acquires the detection voltage VB on the block (step 102). Further, the isolation switches SW1 to SW4 are set to the SW pattern 4 (step 103), and the detection voltage VG under the block is acquired (step 104).

If the detected voltage VB is not lower than the threshold value (Vth) (N in step 105), the control device 4 fixes the system main relay SMR-G on, that is, welds the system main relay SMR-G. It is detected (step 106). If the detected voltage VG is not lower than the threshold value (Vth) (N in step 107), the system main relay SMR-B is fixed to be on, that is, the welding of the system main relay SMR-B is detected (step 108). ). If both the detected voltages VB and VG are equal to or lower than the threshold value (Vth) (Y in step 105, Y in step 107), it is determined that both the system main relays SMR-B and SMR-G are normal.

The detection of the voltage of each block (steps 101 and 102 and steps 103 and 104) and the determination of whether the system main relays SMR-B and SMR-G are normal (steps 105 and 106 and steps 107 and 108) are as follows. You may make it implement reversely.

Embodiment 2.
FIG. 9 is a circuit configuration diagram of the battery system in the present embodiment. The same components as those in the first embodiment are designated by the same reference numerals and the description thereof will be omitted.

In the first embodiment, it is assumed that the high resistances R1 to R8 connecting the battery pack 1 and the body GND are only the resistances shown in FIG. However, the leak detection circuit 6 is mounted in the actual circuit configuration. In the leakage detection circuit 6, the leakage current of the coupling capacitor between the negative electrode side of the assembled battery 1 and the body GND cannot be ignored, and a resistance of at least 1.5 MΩ is connected as an insulation resistance. Then, even when the system main relays SMR-B and SMR-G are normal, the body GND is pulled to the negative electrode side of the assembled battery 1, and thus the voltage VB described with reference to FIG. 4 does not become 0V. It becomes difficult to determine that the main relays SMR-B and SMR-G are normal. Therefore, the SW pattern 3 (only the insulating switch SW1 is turned on) described in the first embodiment cannot detect welding.

Therefore, in the present embodiment, between the system main relay SMR-B on the positive line BL and the connection point of the resistor R5, and between the system main relay SMR-G on the negative line GL and the connection point of the resistor R6. , A bidirectional DCDC converter (bidirectional DDC) 7 is provided. The bidirectional DCDC converter 7 also transfers energy from the auxiliary battery to the assembled battery 1 to an existing converter that prevents energy loss from the assembled battery 1 to the auxiliary battery (not shown). It is a converter that is configured by adding functions.

FIG. 10 is a circuit diagram in which parts of the circuit shown in FIG. 9 other than those contributing to the potential VGND of the body GND are simplified. In FIG. 10, the resistance R9 is an insulation resistance and is set to 1.5 MΩ. Further, the output voltage when the bidirectional DCDC converter 7 is activated is 200V.

FIG. 11 shows the SW pattern, the on/off states of the insulating switches SW1 to SW4 in the SW pattern, the voltage detected during the SW pattern, and the welding of the system main relays SMR-B and SMR-G in the present embodiment. It is a figure which shows the combination of detection. The circuit operation in the present embodiment will be described below with reference to FIG. The controller 4 controls the driving of the bidirectional DCDC converter 7.

In the present embodiment, in order to detect the voltages above and below the block, SW pattern 1, that is, all the insulating switches SW1 to SW4 are turned on to detect the voltages VB and VG. When the voltage is not detected, the SW pattern 2, that is, all the insulation switches SW1 to SW4 are turned off. The control device 4 thus uses the voltage detection circuit 5 for voltage detection.

Next, a circuit operation for detecting a defect that at least one of the system main relays SMR-B and SMR-G is welded and at least one of the power lines BL and GL is fixed in the closed state will be described.

In order to detect a malfunction, the control device 4 turns off both the system main relays SMR-B and SMR-G, turns on the SW pattern 4, that is, the isolation switch SW4, and simultaneously turns on the other isolation switches SW1 to SW3. Turn off. The state of the circuit at this time is shown in FIG. Here, it is assumed that the system main relays SMR-B and SMR-G both operate normally and are in the open state.

At this time, since the insulation switch SW4 is on, the potential V4 of the negative terminal under the block becomes the battery potential 0V in the insulation switch SW4. Since the body GND is connected to the assembled battery 1 via the insulation switch SW4, the potential VGND of the body GND becomes 0 V, which is the same as the minus terminal under the block. Further, since the isolation switches SW1 to SW3 are off, the potentials V1 to V3 are 0 V, which is the same as the potential VGND of the body GND.

Thus, the potentials V1 and V2 of the terminals on the block are both 0V, and the detection voltage VB on the block is 0V. Similarly, the potentials V3 and V4 of the terminals under the block are both 0V, and the detection voltage VG on the block is 0V. As in this example, when the system main relays SMR-B and SMR-G are not welded and are normally turned off under the control of the control device 4, if only the insulation switch SW4 is turned on, each block of the blocks is turned on. The detection voltages VB and VG are both 0V.

Here, it is assumed that the control device 4 controls both the system main relays SMR-B and SMR-G to be turned off, but the system main relay SMR-B remains closed due to welding. The state of the circuit at this time is shown in FIG. In this case, the potential V4 of the minus terminal under the block becomes 0V as described above. On the other hand, the body GND is connected to the negative electrode side of the assembled battery 1 via the insulation switch SW4, and at the same time, is connected to the positive electrode side of the assembled battery 1 since the system main relay SMR-B is in the ON state. Further, the potential VGND of the body GND becomes 39V higher than 0V due to the connection relationship of the resistors R1 to R8 because the voltage rises in the system main relay SMR-B, so the potentials V1 to V3 also become 39V. As a result, the detection voltage VG under the block becomes V3(39V)-V4(0V)=39V. The detection voltage VB on the block is V1(39V)-V2(39V)=0V.

Further, when the control device 4 controls the system main relays SMR-B and SMR-G to be turned off, but the system main relay SMR-G remains closed due to welding (FIG. 14), the system main relay Even when both SMR-B and SMR-G remain in the closed state due to welding (FIG. 15), the detection voltage VG under the block is V3(39V)-V4(0V)=39V and on the block similarly to the above. The detection voltage VB is V1(39V)-V2(39V)=0V.

FIG. 16 is a diagram schematically showing the relationship between the SW patterns 3 and 4 and the detected voltage by the circuit operation described above. In the present embodiment, since the output voltages of the battery pack 1 and the bidirectional DCDC converter 7 are equal, the potential VGND of the body GND becomes the same potential regardless of where the system main relays SMR-B and SMR-G are welded. Therefore, when the welding is performed (FIGS. 13 to 15), the output voltages above and below the block are the same, and when the insulation switches SW1 to SW4 are set to SW pattern 4 and the detection voltage under the block is referred to, the detection voltage exceeds the threshold value. Can determine that at least one of the system main relays SMR-B and SMR-G is welded. In the case of the present embodiment, since the SW pattern 3 has the leakage resistance R9 (1.5 MΩ), whether the system main relays SMR-B and SMR-G are normal or abnormal (welding) is accurately detected in the detection voltage on the block. There is no difference that can be determined in step S3, and the detection voltage under the block is set by referring to the SW pattern 4. The processing described above will be described with reference to the flowchart shown in FIG.

The control device 4 sets the insulating switches SW1 to SW4 to the SW pattern 1 (step 201) and acquires the detection voltages VB and VG above and below the block (step 202). Then, the sum of the detected voltages VB and VG is set as the output voltage from the bidirectional DCDC converter 7 (step 203). In the case of the present embodiment, as described above, 200V=(120V+80V).

Subsequently, the control device 4 sets the insulation switches SW1 to SW4 to the SW pattern 4 (step 204) and acquires the detection voltage VG under the block (step 205).

Then, the control device 4 determines that at least one of the system main relays SMR-B and SMR-G is fixed to be on, that is, the system main if the detected voltage VG is not equal to or lower than the threshold value (Vth) (N in step 206). Welding of the relays SMR-B and SMR-G is detected (step 207). On the other hand, when the detected voltage VG is equal to or lower than the threshold value (Vth) (Y in step 206), it is determined that both the system main relays SMR-B and SMR-G are normal (step 208).

Embodiment 3.
FIG. 18 is a circuit configuration diagram of the battery system in the present embodiment. The same components as those in the first and second embodiments are designated by the same reference numerals and the description thereof will be omitted.

In the present embodiment, the differential amplifier 51 in the voltage detection circuit 5 is replaced with the flying capacitor circuit 8.

FIG. 19 shows the SW pattern, the on/off states of the insulating switches SW1 to SW4 in the SW pattern, the voltage detected during the SW pattern, and the welding of the system main relays SMR-B and SMR-G in the present embodiment. It is a figure which shows the combination of detection. The circuit operation in this embodiment will be described below with reference to FIG.

In the present embodiment, in order to detect the voltages above and below the block, first, all the insulating switches SW1 to SW6 are turned off, and then the SW pattern 5, that is, the insulating switches SW1 and SW2 are turned on to charge the capacitor 9. .. After charging, the SW pattern 7, that is, the insulating switches SW1 and SW2 are turned off, and at the same time, the insulating switches SW5 and SW6 are turned on. As a result, the voltage charged in the capacitor 9 is detected as the voltage VB.

Similarly, after turning off all the insulating switches SW1 to SW6, the SW pattern 6, that is, the insulating switches SW3 and SW4 are turned on to charge the capacitor 9. After charging, the SW pattern 7, that is, the insulating switches SW3 and SW4 are turned off, and at the same time, the insulating switches SW5 and SW6 are turned on. As a result, the voltage charged in the capacitor 9 is detected as the voltage VG.

Since the welding detection of the system main relays SMR-B and SMR-G is basically the same as that of the second embodiment, the description thereof will be omitted. However, when the insulation switch SW1 is turned on by the SW pattern 3, it is necessary to also turn on the insulation switch SW5. Further, when the insulation switch SW4 is turned on by the SW pattern 4, it is necessary to also turn on the insulation switch SW6.

Fourth Embodiment
FIG. 20 is a diagram showing a main part of the circuit configuration of the battery system in the present embodiment. The same components as those in the third embodiment will be assigned the same reference numerals and explanations thereof will be omitted.

In each of the above-described embodiments, since the assembled battery includes the two battery blocks B and G, the voltage detection circuit 5 has the two channels of the block BB and the block BG, but the present invention is not limited to this. It is possible to detect the welding of the system main relays SMR-B and SMR-G by operating in the same manner as above for 1 channel or 3 channels or more.

Although FIG. 20 shows a configuration including four blocks, as shown in FIG. 20, the battery block 11 included in the assembled battery 1 is connected to the positive electrode side of the battery block B closest to the positive electrode line BL. For the insulation switch SW1 and the insulation switch SW4 connected to the negative electrode side of the battery block G included in the assembled battery 1 that is closest to the negative electrode line GL, as compared with the above-described first to third embodiments. By performing the on/off control that has been performed, it is possible to achieve the same operational effects as in the first to third embodiments.

Embodiment 5.
FIG. 21 is a circuit configuration diagram of the battery system in the present embodiment. The same components as those in the second embodiment are designated by the same reference numerals and the description thereof will be omitted. FIG. 21 shows an AC charger 10 that charges an assembled battery 1 by supplying external power. Further, in FIG. 21, the auxiliary battery 12 is also shown. In the plug-in hybrid car, the AC charger 10 is connected via the charging relays BR-B and BR-G separately from the system main relays SMR-B and SMR-G. More specifically, the positive electrode side of AC charger 10 is connected to positive electrode line BL between assembled battery 1 and system main relay SMR-B via charging relay BR-B. Moreover, the negative electrode side of the AC charger 10 is connected to the negative electrode line GL between the battery pack 1 and the system main relay SMR-G via the charging relay BR-G.

In the welding detection method described above, it may not be possible to determine which of the system main relays SMR-B and SMR-G and the charging relays BR-B and BR-G is welded. For example, in order to detect the welding of the system main relay SMR-B, when the bidirectional DCDC converter 7 is stepped up and the insulation switch SW4 is turned on to detect the voltage VG under the block, the system main relay SMR-B is Whether the charging relay BR-B is welded or not, the potential of the body GND is raised by the step-up by the bidirectional DCDC converter 7, and the voltage detection value rises. Certainly, the welding of the system main relay SMR-B can be detected, but it cannot be separated from the welding of the charging relay BR-B.

Therefore, in the present embodiment, a logic for detecting the variation amount of the detected voltage when the boosted voltage of the bidirectional DCDC converter 7 is varied is added. Here, it is assumed that only the isolation switch SW4 is turned on. When the bidirectional DCDC converter 7 is driven, since the system main relay SMR-B is welded, the potential of the body GND fluctuates according to the fluctuation of the boosted voltage of the bidirectional DCDC converter 7. On the other hand, when the system main relay SMR-B is not welded, the potential of the body GND does not change because it is not affected by the change in the boosted voltage of the bidirectional DCDC converter 7. Even if the charging relays BR-B and BR-G are welded, the potential of the body GND does not fluctuate, and therefore, they can be separated. The welding detection process according to the present embodiment described above will be described below with reference to the flowchart shown in FIG.

The control device 4 first stops the boosting of the bidirectional DCDC converter 7 (step 501), and sets the SW pattern 3 in this state (step 502). That is, only the isolation switch SW1 is turned on to detect the voltage VB on the block (step 503). The voltage VB detected with the boosting of the bidirectional DCDC converter 7 stopped is set to VB1_OFF. Subsequently, the control device 4 sets the SW pattern 4 (step 504). That is, only the insulating switch SW4 is turned on to detect the voltage VG under the block (step 505). The voltage VG detected with the boosting of the bidirectional DCDC converter 7 stopped is set to VG4_OFF.

When the voltage above and below the block is detected when the bidirectional DCDC converter 7 is in the off state, the control device 4 activates the bidirectional DCDC converter 7 to boost the voltage (step 506). In this state, SW pattern 3 is set (step 507). That is, only the isolation switch SW1 is turned on to detect the voltage VB on the block (step 508). The voltage VB detected while the bidirectional DCDC converter 7 is boosting is set to VB1_ON. Subsequently, the control device 4 sets the SW pattern 4 (step 509). That is, only the isolation switch SW4 is turned on to detect the voltage VG under the block (step 510). The voltage VG detected with the boosting of the bidirectional DCDC converter 7 stopped is set to VG4_ON.

As described above, when the voltages when the bidirectional DCDC converter 7 is in the ON state and the OFF state are detected, for example, as described in the second embodiment, the bidirectional DCDC converter 7 is in the ON state and the SW When the voltage VG4_ON detected when the pattern 4 (only the insulating switch SW4 is turned on) is set to the threshold value (here, Vth1) or less (Y in step 511), the system main relays SMR-B and SMR-G are Both are determined to be normal (step 513).

Here, if the system main relays SMR-B and SMR-G are welded as described above, the potential of the body GND changes. As described in the first embodiment, the detected voltages at the upper and lower sides of the block are equal to the potentials of the body GND, so that the fluctuation amount of the potential of the body GND is equal to the fluctuation amounts of the detected voltages at the upper and lower sides of the block. That is, since the difference between the detection voltages VB and VG when the bidirectional DCDC converter 7 is in the OFF state and the ON state is the variation amount, the absolute value of the difference between VB1_OFF and VB1_ON is the detection voltage VB on the block. In the case of the detected voltage VG under the block, the absolute value of the difference between VG4_OFF and VG4_ON is calculated as the fluctuation amount of the potential of the body GND. Then, when both the respective variation amounts are equal to or less than the threshold value Vth2 preset as the threshold value for determining the presence or absence of the variation (Y in step 512), the charging relays BR-B and BR-G are welded. To determine. That is, the welding of the charging relays BR-B and BR-G is detected (step 514). On the other hand, if any of the fluctuation amounts exceeds the threshold value Vth2 (N in step 512), it is determined that the system main relays SMR-B and SMR-G are welded. That is, the welding of the system main relays SMR-B and SMR-G is detected (step 515).

In the present embodiment, the voltages VB and VG both above and below the block are detected. However, in the actual circuit design, there is a possibility that either the top or bottom of the block may exceed the range depending on the welding location. Because. Therefore, if a voltage fluctuation occurs either on the block or under the block, it is determined that the system main relays SMR-B and SMR-G are welded. On the other hand, if the voltage fluctuation does not occur either on the block or under the block, it is determined that the charging relays BR-B and BR-G are welded.

Further, in the present embodiment, there are two types of relays connected to the battery pack 1; the system main relays SMR-B and SMR-G and the charging relays BR-B and BR-G. It is possible to separate only by the step-up fluctuation, but in the case of a battery system in which three or more types of relays are connected, if the AC charger 10 and the like are stepped up, it is possible to detect the welding of each relay. ..

Sixth Embodiment
In each of the above-described embodiments, the welding of the system main relays SMR-B and SMR-G is detected by controlling the on/off states of the insulating switches SW1 to SW4. However, if the insulation switches SW1 to SW4 are defective, the welding of the system main relays SMR-B and SMR-G may not be normally detected. Even if the system main relays SMR-B and SMR-G are normally operated, if they are erroneously detected as welding, traveling is prohibited in a situation where batteryless traveling is possible. In the present embodiment, it is possible to prevent excessive failure such as travel prohibition by detecting abnormalities in the system main relays SMR-B, SMR-G or the insulation switches SW1 to SW4 so that they can be separated. It is characterized by

The circuit configuration of the battery system in the present embodiment may be the same as that in the first embodiment (FIGS. 1 and 2). The present embodiment is characterized by the on/off control of the insulating switches SW1 to SW4.

FIG. 23 shows the SW pattern, the on/off states of the insulating switches SW1 to SW4 in the SW pattern, the voltage detected during the SW pattern, and the welding of the system main relays SMR-B and SMR-G in the present embodiment. It is a figure which shows the combination of detection. The circuit operation in the present embodiment will be described below with reference to FIG. 23 and FIG. 3 used in the first embodiment.

The control device 4 turns off both the system main relays SMR-B and SMR-G, and turns on only the SW pattern 3, that is, the insulating switch SW1, and simultaneously turns off the other insulating switches SW2 to SW4. The state of the circuit at this time is as shown in FIG. Here, assuming that the system main relays SMR-B and SMR-G both operate normally and are in the open state, the detection voltage VB on the block is V1 (200V) as described in the first embodiment. -V2 (200V)=0V, and the detection voltage VG under the block also becomes V3 (200V)-V4 (200V)=0V.

Subsequently, the control device 4 controls the system main relays SMR-B and SMR-G so that both are turned off, but it is assumed that the system main relay SMR-G remains closed due to welding. The state of the circuit at this time is as shown in FIG. As described above, in such a state, the potential V1 of the plus terminal on the block is 200V and the potential V2 of the minus terminal on the block is 67V, so the detection voltage VB on the block is V1(200V)-V2(67V). =133V. The detection voltage VG under the block is V3(67V)-V4(67V)=0V.

Here, it is assumed that both the system main relays SMR-B and SMR-G are turned off according to the off control by the control device 4, while the control device 4 turns on only the SW pattern 3, that is, the insulation switch SW1. It is assumed that the other insulation switches SW2 to SW4 are controlled to be turned off, but the insulation switch SW2 remains on due to a problem. The state of the circuit at this time is shown in FIG.

In this case, since the isolation switches SW1 and SW2 are both in the ON state, the differential amplifier 51 is connected to the battery block B, so that the potential V1 is 200V and the potential V2 is 80V. The potential of the body GND is 140 V, which is the average value of the potentials V1 and V2, and thus the potentials V3 and V4 are both 140 V. Therefore, the detection voltage VB on the block is V1 (200V)-V2 (80V)=120V. The detection voltage VG under the block is V3(140V)-V4(140V)=0V.

Thus, when the control device 4 sets the SW pattern 3 (only the insulation switch SW1 is turned on), the system main relay SMR-G does not operate normally and remains in the on state, but all the insulation switches SW1 ~ When SW4 operates normally (only the insulation switch SW1 shown in FIG. 5 is on), the detection voltage VB (=133V) and the system main relays SMR-B and SMR-G both operate normally and are turned off. However, the detection voltage VB (=120 V) when the insulation switch SW2 is turned on without normally operating (the insulation switches SW1 and SW2 shown in FIG. 24 are on) shows a close value. In other words, it is difficult to distinguish when the system main relay SMR-G is abnormal and when the insulation switch SW2 is abnormal. Therefore, in the present embodiment, the location where the abnormality has occurred can be determined as follows.

That is, in this embodiment, the SW pattern 4, that is, only the insulation switch SW4 is turned on, and the other insulation switches SW1 to SW3 are turned off. FIG. 25 shows the state of the circuit when the isolation switch SW2 operates normally. The system main relay SMR-G does not operate normally and remains in the ON state.

At this time, since the insulation switch SW4 is on, the potential V4 becomes the battery potential 0V in the insulation switch SW4. Since the body GND is connected to the assembled battery 1 only through the insulation switch SW4, the potential VGND of the body GND becomes 0V. Further, since the isolation switches SW1 to SW3 are off, the potentials V1 to V3 are 0 V, which is the same as the potential VGND of the body GND. As a result, the detection voltages VB and VG of each block become 0V.

FIG. 26 shows the state of the circuit when the control device 4 controls the SW pattern 4 (only the insulation switch SW4 is turned on), but the insulation switch SW2 does not operate normally. The system main relay SMR-G operates normally and remains in the off state.

At this time, since the insulation switch SW4 is on, the potential V4 becomes the battery potential 0V in the insulation switch SW4. Further, since the isolation switch SW2 is also turned on, the potential V2 becomes the battery potential 80V in the isolation switch SW2. Since the body GND is connected to the assembled battery 1 via the insulation switches SW2 and SW4, the potential VGND of the body GND is 40V which is the average value of the respective potentials V2 and V4. Since the isolation switches SW1 and SW3 are off, the potentials V1 and V3 are 40V, which is the same as the potential VGND of the body GND.

As a result, the detection voltage VB on the block becomes V1(40V)-V2(80V)=-40V, and the detection voltage VG under the block becomes V3(40V)-V4(0V)=40V.

In the first embodiment, the abnormality determination of the system main relays SMR-B and SMR-G is set to SW pattern 3 (only the insulating switch SW1 is turned on) and the detected voltage VB on the block is referred to, or the SW pattern 4 is set. (Only the insulation switch SW4 is turned on) to refer to the detection voltage VG under the block. On the other hand, in the present embodiment, when the welding of the system main relays SMR-B, SMR-G or the insulation switches SW1 to SW4 is separated, the SW pattern 3 (only the insulation switch SW1 is turned on) is set in reverse to the above. The detection voltage VG under the block is referred to, or the SW pattern 4 (only the insulating switch SW4 is turned on) is set to refer to the detection voltage VB above the block.

FIG. 27 is a diagram schematically showing the relationship between the SW patterns 1, 3, 4 and the detected voltage by the circuit operation described above. As shown in FIG. 27, in the present embodiment, similarly to the first embodiment, a threshold value () is set as a criterion for determining whether the system main relays SMR-B and SMR-G are normal or abnormal (welding) with respect to the SW pattern 3. Vth) is set in advance. The threshold value may be set to an appropriate value with reference to the voltage of the assembled battery 1, the values of the resistors R1 to R8, and the like. Furthermore, in the present embodiment, the threshold value (-Vth) is set not only for the SW pattern 4 but also for the minus, in advance.

As is clear from FIG. 27, when the insulation switches SW1 and SW2 are fixed, when the voltage VB on the block is detected in the SW pattern 4, the value becomes equal to or higher than the predetermined threshold value. When the insulation switches SW3 and SW4 are fixed, when the voltage VG under the block is detected in the SW pattern 3, the value becomes equal to or higher than a predetermined threshold value. On the other hand, even if the system main relays SMR-B and SMR-G are welded, the voltages VB and VG become 0V in any case. Therefore, it is possible to distinguish whether the system main relays SMR-B, SMR-G or the insulation switches SW1 to SW4 have an abnormality. The processing described above will be described with reference to the flowchart shown in FIG.

The control device 4 sets the insulation switches SW1 to SW4 to the SW pattern 3 (step 601). That is, the control device 4 detects the voltage VB (VB3) above the block and the voltage VG (VG3) below the block with only the insulation switch SW1 turned on (step 602).

Next, the insulating switches SW1 to SW4 are set to the SW pattern 4 (step 603). That is, the control device 4 detects the voltage VB (VB4) above the block and the voltage VG (VG4) below the block with only the insulation switch SW4 turned on (step 604). Note that steps 601, 602 and steps 603, 604 may be processed in reverse.

Here, when both the absolute values of the voltage VB (VB3) on the block and the voltage VG (VG4) under the block are both equal to or less than the threshold value (Vth) (Y in step 605), the system main relays SMR-B and SMR-G. Also, the isolation switches SW1 to SW4 are both determined to be normal (step 607). If not, it means that the system main relay SMR-B, the system main relay SMR-G, or any one of the isolation switches SW1 to SW4 is defective, so in the present embodiment, the isolation is performed here. Processing will be executed.

That is, in the case where a failure occurs in any of them (N in step 605), when the absolute values of the voltage VB (VB4) above the block and the voltage VG (VG3) below the block are both below the threshold value (Vth). (Y in step 606), the welding of at least one of the system main relay SMR-B and the system main relay SMR-G will be detected (step 608). On the other hand, if at least one of the absolute values exceeds the threshold value Vth (N in step 606), welding of any of the insulating switches SW1 to SW4 is detected (step 609).

As described above, when welding of the system main relays SMR-B and SMR-G is detected, only the insulation switch SW1 is turned on to refer to the detection voltage VB on the block, or only the insulation switch SW4 is turned on to detect the bottom of the block. The reference voltage of the detection voltage VG is referred to, but the upper and lower sides of the block referring to the detection voltage are switched when the defect occurrence point is divided. In other words, by replacing the upper and lower parts of the block, it is possible to isolate the location where the defect has occurred. In the present embodiment, as described above, it is possible to isolate the occurrence of a malfunction in any of the system main relays SMR-B, SMR-G or the insulation switches SW1 to SW4.

Embodiment 7.
The circuit configuration of the battery system in the present embodiment may be the same as that in the second embodiment (FIGS. 9 and 10). In the present embodiment, even in the circuit configuration including the leakage detection circuit 6 and the bidirectional DCDC converter 7 as described above, the technique described in the sixth embodiment, that is, the system main relays SMR-B, SMR-G or the insulation switches SW1 to SW1. It is to be explained that the technology of switching the upper and lower sides of the block used for the abnormality determination when the abnormality of the SW4 is separated is applicable.

FIG. 29 shows, in the present embodiment, a SW pattern, ON/OFF states of insulating switches SW1 to SW4 in the SW pattern, voltages detected during the SW pattern, and welding of system main relays SMR-B and SMR-G. It is a figure which shows the combination of detection. In the present embodiment, by combining FIG. 29 and FIG. 11 used in the second embodiment, it is possible to separate an abnormality between the system main relays SMR-B and SMR-G and the isolation switches SW1 to SW4. Become. Since the circuit operation itself is the same as that of the sixth embodiment, its explanation is omitted.

FIG. 30 is a diagram schematically showing the relationship between the SW patterns 3 and 4 and the detected voltage by the circuit operation described above. In the case of the present embodiment, similarly to the second embodiment, in the SW pattern 3, whether the system main relays SMR-B and SMR-G are normal to the detection voltage VB on the block due to the leakage resistance R9 (1.5 MΩ). There is no difference that can accurately determine whether there is an abnormality (welding), and is not used for abnormality determination and separation determination. Instead, the SW pattern 4 is set to determine whether the detection voltage VG under the block is normal or abnormal. Then, when it is determined that there is an abnormality, the determination is made based on the detection voltage VG on the block and the detection voltage VG on the block, and the detection voltage VG on the block and the detection voltage VG under the block. The processing described above will be described with reference to the flowchart shown in FIG.

First, the control device 4 activates the bidirectional DCDC converter 7 to boost the voltage (step 701). In this state, SW pattern 4 is set (step 702). That is, the control device 4 detects the voltage VB (VB4) above the block and the voltage VG (VG4) below the block with only the insulation switch SW4 turned on (step 703).

Subsequently, the control device 4 sets the SW pattern 3 (step 704). That is, the control device 4 detects the voltage VG (VG3) under the block while only the insulation switch SW1 is turned on (step 705).

When the voltages above and below the block are detected as described above, when the bidirectional DCDC converter 7 is in the ON state and the SW pattern 4 (only the insulating switch SW4 is ON) is set as described in the second embodiment. When the voltage VG detected in step S6 is equal to or lower than the threshold value (Vth) (Y in step 706), it is determined that both system main relays SMR-B and SMR-G are normal (step 708). If this is not the case, the failure occurrence point is to be separated (N in step 706), but the control device 4 determines that the absolute values of the voltage VB (VB4) above the block and the voltage VG (VG3) below the block are both If it is less than or equal to the threshold value (Vth) (Y in step 707), welding of at least one of the system main relay SMR-B and the system main relay SMR-G will be detected (step 709). On the other hand, when at least one of the absolute values exceeds the threshold value Vth (N in step 707), welding of any of the insulation switches SW1 to SW4 is detected (step 710).

In the present embodiment, as described above, it is possible to distinguish whether the system main relays SMR-B, SMR-G or the insulation switches SW1 to SW4 are stuck.

1 assembled battery, 2 electric equipment, 3 booster circuit, 4 control device, 5 voltage detection circuit, 6 leakage detection circuit, 7 bidirectional DCDC converter (bidirectional DDC), 8 flying capacitor circuit, 9 capacitor, 10 charger, 11 , B, G battery block, 12 auxiliary battery, 51 differential amplification part, 52 insulation switch part, BB, BG block, BL positive line, BR-B, BR-G charging relay, GL negative line, R1 to R9 Resistance, SMR-B, SMR-G system main relay, SW1 to SW4 isolation switch.

Claims (2)

An assembled battery including at least a first battery block and a second battery block connected in series, an electric device supplied with electric power from the assembled battery, a positive electrode side of the first battery block, and a positive electrode side terminal of the electric device. A positive electrode side system main relay provided on a positive electrode side power line connecting to the negative electrode side power line connecting the negative electrode side of the second battery block and a negative electrode side terminal of the electric device; A voltage detection circuit having a detection unit that is connected to the positive electrode side and the negative electrode side of each of the battery blocks via an insulation switch without passing through the system main relays of the positive electrode side and the negative electrode side and detects the voltage of each of the battery blocks. In a vehicle battery system including
A control device for controlling ON/OFF of each of the system main relays and the insulation switch is provided,
When the control device turns off the system main relays and sets the insulation switches to a predetermined on/off state, the voltage of the first battery block or the second battery block is set to the predetermined on/off state. A battery system, wherein at least one of the system main relays is determined to be abnormal when a threshold value corresponding to or higher than the threshold value is set. The control device, when only the insulation switch connected to the positive electrode side of the assembled battery among the insulation switches is turned on, the voltage connecting the insulation switch connected to the negative electrode side of the assembled battery. Connect the detection value of the detection circuit and the insulation switch connected to the positive side of the battery pack when only the insulation switch connected to the negative side of the battery pack of the insulation switch is turned on. The detection value of the voltage detection circuit, and, if both of the acquired detection values are less than a predetermined threshold value is determined to be a failure of the system main relay, any of the acquired detection value is the predetermined The battery system according to claim 1, wherein it is determined that the insulation switch has failed when a threshold value is exceeded.