Charger connection detection circuit

Abstract

To detect whether or not each charger and a power storage device are connected to each other both on a charger side and a power storage device side, even if a specification of each connection detection of each charger is different.SOLUTION: A charger connection detection circuit 1 comprises: a control part Cnt that is provided by a power storage device BA, and comprises a power supply Pb and an input terminal Tin; and photocoupler PC1 and PC2 that reduce a voltage input into the input terminal Tin when it is switched from an OFF into an ON. In the control part Cnt, the photocoupler PC1 is switched from the OFF to the ON when a current flows to a charger Ch1 via the photocoupler PC1 from the power supply Pb, and a voltage input into the input terminal Tin is deteriorated, or the photocoupler PC2 is switched from the OFF to the ON when the current flowing in the photocoupler PC2 from the power supply Pc provided to a charger Ch2, and it is detected that the charger Ch1 or the charger Ch2 is connected to the power storage device BA when the voltage input into the input terminal Tin is deteriorated.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a charger connection detection circuit that detects that a charger is connected to a power storage device. [Background technology]

[0002] There is a charger connection detection circuit that detects that the first charger is connected to the power storage device when a current flows from a power source on the power storage device side through a photocoupler on the power storage device side to a photocoupler on the first charger side, causing the photocoupler on the power storage device side to switch from off to on. Note that when the photocoupler on the first charger side switches from off to on, the first charger detects that the power storage device is connected to the first charger. Patent Document 1 is a related technique.

[0003] Another charger connection detection circuit detects that the second charger is connected to the power storage device when a current flows from the power supply on the second charger side to multiple voltage dividing resistors on the second charger side and also flows to multiple voltage dividing resistors on the power storage device side, causing a voltage increase across the connection point of the multiple voltage dividing resistors on the power storage device side. Note that the second charger detects that the power storage device is connected to the second charger when the voltage across the connection point of the multiple voltage dividing resistors on the second charger side decreases.

[0004] However, in the charger connection detection circuit, the connection detection specifications (method) on the charger connection detection circuit side correspond to the connection detection specifications on the first charger side but do not correspond to the connection detection specifications on the second charger side, so while it can detect that the first charger is connected to the power storage device, it cannot detect that the second charger is connected to the power storage device.

[0005] Furthermore, in the other charger connection detection circuit, the connection detection specifications on the other charger connection detection circuit side correspond to the connection detection specifications on the second charger side but do not correspond to the connection detection specifications on the first charger side, so while it can detect that the second charger is connected to the power storage device, it cannot detect that the first charger is connected to the power storage device.

[0006] In addition, the first charger can detect that a power storage device having the above-mentioned charger connection detection circuit is connected to the first charger, but cannot detect that a power storage device having the above-mentioned other charger connection detection circuit is connected to the first charger.

[0007] In addition, the second charger can detect that a power storage device including the other charger connection detection circuit is connected to the second charger, but cannot detect that a power storage device including the charger connection detection circuit is connected to the second charger.

[0008] In other words, in the above-mentioned charger connection detection circuit and the other charger connection detection circuits, if the connection detection specifications of each charger are different from each other, there is a concern that the charger side and the storage device side will not be able to detect whether each charger and the storage device are connected to each other. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] JP 2015-220002 A Summary of the Invention [Problem to be solved by the invention]

[0010] An object of one aspect of the present invention is to provide a charger connection detection circuit that is capable of detecting whether each charger and a power storage device are connected to each other on the charger side and the power storage device side, respectively, even if the connection detection specifications of each charger are different from each other. [Means for solving the problem]

[0011] A charger connection detection circuit according to one embodiment of the present invention is a charger connection detection circuit provided in a power storage device, and includes a power storage device-side power supply, a control unit having an input terminal, and first and second photocouplers that reduce the voltage input to the input terminal when switched from off to on.

[0012] The control unit detects that the first charger or the second charger is connected to the energy storage device when a current flows from the energy storage device side power supply to the first charger via the first photocoupler, causing the first photocoupler to switch from off to on and the voltage input to the input terminal to decrease, or when a current flows from the charger side power supply provided in the second charger to the second photocoupler, causing the second photocoupler to switch from off to on and the voltage input to the input terminal to decrease.

[0013] For example, the first charger detects that the power storage device is connected to the first charger when a current flows from the power source on the power storage device side through the first photocoupler to the photocoupler on the first charger side, causing the photocoupler on the first charger side to switch from off to on. The second charger detects that the power storage device is connected to the second charger when a current flows from the power source on the second charger side (charger side power source) to a plurality of voltage dividing resistors on the second charger side and a current flows from the power source on the second charger side to the second photocoupler, causing a voltage drop across a connection point between the plurality of voltage dividing resistors on the second charger side. In this way, even if the specifications (methods) for detecting connection of the first and second chargers are different from each other, the charger connection detection circuit according to one embodiment of the present invention allows the first and second chargers and the power storage device to detect whether or not the first and second chargers and the power storage device are connected to each other, respectively.

[0014] Moreover, the input terminal may include a first and a second input terminal, and the control unit may be configured to detect that the first charger is connected to the power storage device when the first photocoupler switches from off to on and the voltage input to the first input terminal drops, and to detect that the second charger is connected to the power storage device when the second photocoupler switches from off to on and the voltage input to the second input terminal drops.

[0015] This makes it possible to identify the first charger or the second charger as the charger connected to the power storage device.

[0016] The charger connection detection circuit further includes a connection terminal connectable to a charging cable provided in the first charger or the second charger, a first photodiode provided in the first photocoupler and having an anode terminal connected to the power storage device side power supply, a first phototransistor provided in the first photocoupler and switching from off to on when the first photodiode switches from off to on to reduce the voltage input to the input terminal, a reverse current prevention diode having a cathode terminal connected to the connection terminal and an anode terminal connected to the cathode terminal of the first photodiode via a first resistor, a second photodiode provided in the second photocoupler and having an anode terminal connected to the connection terminal via a second resistor, a second phototransistor provided in the second photocoupler and switching from off to on when the second photodiode switches from off to on to reduce the voltage input to the input terminal, and a collector terminal connected to the cathode terminal of the second photodiode, an emitter terminal connected to ground, and a base terminal connected to the ground via a third resistor and a fourth resistor. and a first Zener diode having a cathode terminal connected to a connection point between the connection terminal and the second resistor and an anode terminal connected to a connection point between the third resistor and the fourth resistor, wherein the control unit detects when a current flows from the power storage device side power supply to the first charger via the first photodiode, the first resistor, the reverse current prevention diode, the connection terminal, and the first charging cable, causing the first photodiode to switch from off to on and a voltage input to the input terminal drops, or when a current flows from the charger side power supply to a base terminal of the npn bipolar transistor via the second charging cable, the connection terminal, the first Zener diode, and the third resistor, causing the npn bipolar transistor to switch from off to on, and then a current flows from the charger side power supply to a collector terminal of the npn bipolar transistor via the second charging cable, the connection terminal, the second resistor, and the second photodiode, causing the second photodiode to switch from off to on and a voltage input to the input terminal drops.The power storage device may be configured to detect whether the first charger or the second charger is connected to the power storage device.

[0017] Moreover, the charger connection detection circuit may include a second Zener diode having a cathode terminal connected to the cathode terminal of the first Zener diode and an anode terminal connected to the anode terminal of the first Zener diode via a switch, and having a breakdown voltage lower than that of the first Zener diode, and the control unit may be configured to detect that the first charger or the second charger is connected to the power storage device, and then when preparations for charging a battery included in the power storage device are completed, to switch the switch from a cut-off state to a conductive state, thereby causing the current flowing from the charger-side power supply to the first Zener diode to flow to the second Zener diode, thereby maintaining the on state of the npn bipolar transistor.

[0018] As a result, when the switch is switched from a cut-off state to a conductive state, the voltage applied to the charging cable can be changed, and this voltage change can be used to communicate from the storage device to the second charger that the battery is ready to be charged.

[0019] Furthermore, the charger connection detection circuit may include first and second voltage dividing resistors connected between the connection terminal and the ground, and the control unit may be configured to determine that a malfunction has occurred in at least one of the charger connection detection circuit, the first charger, and the second charger when a voltage applied to a connection point between the first voltage dividing resistor and the second voltage dividing resistor is greater than an upper limit value, or when a voltage applied to a connection point between the first voltage dividing resistor and the second voltage dividing resistor is smaller than a lower limit value that is smaller than the upper limit value.

[0020] This notifies the user that a failure has occurred in the charger connection detection circuit, thereby enabling the charger connection detection circuit to recover quickly. Effect of the Invention

[0021] According to the present invention, even if the connection detection specifications of each charger are different from each other, the charger side and the power storage device side can each detect whether or not each charger and the power storage device are connected to each other. [Brief description of the drawings]

[0022] [Figure 1] FIG. 2 is a diagram illustrating an example of a charger connection detection circuit according to the embodiment. [Diagram 2] FIG. 11 is a diagram illustrating a first modified example of a charger connection detection circuit according to an embodiment. [Diagram 3] FIG. 11 is a diagram illustrating a second modified example of the charger connection detection circuit according to the embodiment. [Figure 4] FIG. 11 is a diagram illustrating a third modified example of the charger connection detection circuit according to the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0023] Hereinafter, the embodiments will be described in detail with reference to the drawings.

[0024] FIG. 1 is a diagram illustrating an example of a charger connection detection circuit according to an embodiment.

[0025] 1 is provided in the power storage device BA, and detects that a charger Ch1 (first charger) or a charger Ch2 (second charger) is connected to the power storage device BA. The power storage device BA is assumed to be mounted on a vehicle such as an industrial vehicle, such as a forklift, or an electric vehicle, and to include a battery (not shown) that supplies power to a lifting device, a traveling motor, etc. As will be described later, the connection detection specifications (method) on the charger Ch1 side and the connection detection specifications on the charger Ch2 side are assumed to be different from each other.

[0026] The charger connection detection circuit 1 also includes a power supply Pb (power supply on the storage device side), a power supply P, a ground gnd, a photocoupler PC1 (first photocoupler), a resistor R1 (first resistor), a pull-up resistor Rp1, a backflow prevention diode D, and a connection terminal T (e.g., an inlet, etc.).

[0027] The charger connection detection circuit 1 also includes a photocoupler PC2 (second photocoupler), a resistor R2 (second resistor), a resistor R3 (third resistor), a resistor R4 (fourth resistor), a ground GND, a Zener diode ZD1 (first Zener diode), an npn bipolar transistor Tr, and a control unit Cnt. The power supply Pb and the power supply P may or may not be insulated from each other. The ground GND and the ground gnd may or may not be insulated from each other. The breakdown voltage of the Zener diode ZD1 is greater than the voltage of the power supply Pb.

[0028] The photocoupler PC1 includes a photodiode PD1 (first photodiode) and a phototransistor PTr1 (first phototransistor), and when a current flows through the photodiode PD1, the photodiode PD1 switches from off to on and emits light, the phototransistor PTr1 receives the light and switches from off to on. In other words, when a current flows through the photocoupler PC1, the photocoupler PC1 switches from off to on.

[0029] The photocoupler PC2 includes a photodiode PD2 (second photodiode) and a phototransistor PTr2 (second phototransistor), and when a current flows through the photodiode PD2, the photodiode PD2 switches from off to on and emits light, the phototransistor PTr2 receives the light and switches from off to on. In other words, when a current flows through the photocoupler PC2, the photocoupler PC2 switches from off to on.

[0030] The anode terminal of the photodiode PD1 is connected to a power supply Pb, and the cathode terminal of the photodiode PD1 is connected to the anode terminal of the backflow prevention diode D via a resistor R1. The cathode terminal of the backflow prevention diode D is connected to the connection terminal T. The collector terminal of the phototransistor PTr1 is connected to the power supply P via a pull-up resistor Rp1 and is also connected to the input terminal Tin of the control unit Cnt, and the emitter terminal of the phototransistor PTr1 is connected to the ground gnd. Note that the voltage Vcc of the power supply P is greater than the voltage Vee of the ground gnd, and for example, the voltage Vcc is 5 [V] and the voltage Vee is 0 [V].

[0031] The anode terminal of the photodiode PD2 is connected to the connection terminal T via a resistor R2, and the cathode terminal of the photodiode PD2 is connected to the collector terminal of an npn bipolar transistor Tr. The emitter terminal of the npn bipolar transistor Tr is connected to ground GND, and the base terminal of the npn bipolar transistor Tr is connected to ground GND via resistors R3 and R4. The cathode terminal of the Zener diode ZD1 is connected to the connection point between the connection terminal T and the resistor R2, and the anode terminal of the Zener diode ZD1 is connected to the connection point between the resistors R3 and R4. The collector terminal of the phototransistor PTr2 is connected to a power supply P via a pull-up resistor Rp2 and is connected to an input terminal Tin of the control unit Cnt, and the emitter terminal of the phototransistor PTr2 is connected to ground gnd.

[0032] The control unit Cnt is configured by, for example, a CPU (Central Processing Unit) or a programmable device (such as an FPGA (Field Programmable Gate Array) or a PLD (Programmable Logic Device)).

[0033] Furthermore, when the voltage input to the input terminal Tin drops, the control unit Cnt detects that the charger Ch1 or the charger Ch2 is connected to the power storage device BA. For example, when the voltage applied to the input terminal Tin becomes smaller than the voltage threshold Vth, the control unit Cnt determines that the voltage applied to the input terminal Tin has dropped. Alternatively, the control unit Cnt acquires the voltage applied to the input terminal Tin at regular intervals, and when all voltages acquired a predetermined number of times in succession are smaller than the voltage threshold Vth, determines that the voltage applied to the input terminal Tin has dropped. Here, the voltage threshold Vth is set to voltage Vcc or voltage Vcc'. The voltage Vcc' is set to voltage Vcc-Vccn, voltage Vcc' is set to voltage Vcc×α, or voltage Vcc' is set to voltage Vcc×α-Vccn. Vccn is a noise component included in the voltage Vcc, and 0<α<1.

[0034] Furthermore, when the control unit Cnt detects that the charger Ch1 or the charger Ch2 is connected to the power storage device BA and receives a charging start instruction from a user or the like, it starts preparation for charging a battery (not shown) provided in the power storage device BA, and starts charging control of the battery when the charging preparation is completed. Alternatively, when the control unit Cnt detects that the charger Ch1 or the charger Ch2 is connected to the power storage device BA, it starts preparation for charging the battery, and starts charging control of the battery when the charging preparation is completed.

[0035] For example, first, during preparation for charging, the control unit Cnt uses CAN (Controller Area Network) communication or the like to transmit and receive data to and from the charger connected to the power storage device BA, thereby identifying the charger Ch1 or charger Ch2 as the charger connected to the power storage device BA, and acquiring information necessary for battery charging control (upper limit value of the charger's output current), etc. Next, during charging control, the control unit Cnt obtains a current command value based on the battery voltage and the upper limit value of the charger's output current, etc., for each control period, and sends the current command value to the charger connected to the power storage device BA. The charger connected to the power storage device BA outputs a current corresponding to the current command value to the power storage device BA. When power is supplied to the battery from the charger connected to the power storage device BA, the battery's charging rate (the ratio of remaining capacity to full charge capacity) increases. Then, when the control unit Cnt determines that the battery is in a fully charged state based on the battery voltage, the current flowing through the battery, etc., it sets the battery's charging rate to 100[%] and ends the charging control.

[0036] <About Charger Ch1>

[0037] The charger Ch1 includes a photocoupler PC, a resistor R, a charging cable Ca1, a ground GND, a pull-up resistor Rp3, a power supply P, a ground gnd, and a control unit Cnt1.

[0038] The photocoupler PC includes a photodiode PD and a phototransistor PTr, and when a current flows through the photodiode PD, the photodiode PD switches from off to on and emits light, and the phototransistor PTr receives the light and switches from off to on. In other words, when a current flows through the photocoupler PC, the photocoupler PC switches from off to on.

[0039] The anode terminal of the photodiode PD is connected to the charging cable Ca1 via a resistor R, and the cathode terminal of the photodiode PD is connected to the ground GND. The collector terminal of the phototransistor PTr is connected to the input terminal Tin1 of the control unit Cnt1 and to a power source P via a pull-up resistor Rp3, and the emitter terminal of the phototransistor PTr is connected to the ground gnd. When a connector Co1 provided at the end of the charging cable Ca1 is connected to a connection terminal T of the power storage device BA by a user's operation, the charger Ch1 and the power storage device BA are connected to each other, and the charger Ch1 is in a state where power can be supplied to the power storage device BA.

[0040] The control unit Cnt1 is configured by, for example, a CPU or a programmable device (such as an FPGA or a PLD).

[0041] Furthermore, when the voltage input to the input terminal Tin1 drops, the control unit Cnt1 detects that the power storage device BA is connected to the charger Ch1. For example, when the voltage applied to the input terminal Tin1 becomes smaller than the voltage threshold Vth1, the control unit Cnt1 determines that the voltage applied to the input terminal Tin1 has dropped. Alternatively, the control unit Cnt1 acquires the voltage applied to the input terminal Tin1 at regular intervals, and when all voltages acquired a predetermined number of times in succession are smaller than the voltage threshold Vth1, determines that the voltage applied to the input terminal Tin1 has dropped. Here, the voltage threshold Vth1 is set to voltage Vcc or voltage Vcc'. The voltage Vcc' is set to voltage Vcc-Vccn, voltage Vcc' is set to voltage Vcc×α, or voltage Vcc' is set to voltage Vcc×α-Vccn. Vccn is a noise component included in the voltage Vcc, and 0<α<1.

[0042] Furthermore, when control unit Cnt1 receives a current command value transmitted from control unit Cnt by CAN communication or the like, control unit Cnt1 outputs a current according to the current command value to power storage device BA via charging cable Ca1.

[0043] <About Charger Ch2>

[0044] The charger Ch2 includes voltage dividing resistors Rd1 and Rd2, a pull-up resistor Rp4, a power supply Pc (charger side power supply), a charging cable Ca2, and a control unit Cnt2. The voltage of the power supply Pc is greater than the voltage of the power supply Pb and the breakdown voltage of the Zener diode ZD1. The resistance values ​​of the voltage dividing resistors Rd1 and Rd2 are greater than the resistance values ​​of the pull-up resistor Rp4 and the resistor R2.

[0045] One terminal of the voltage dividing resistor Rd1 is connected to the charging cable Ca2 and to the power source Pc via a pull-up resistor Rp4, and the other terminal of the voltage dividing resistor Rd1 is connected to the ground GND via a voltage dividing resistor Rd2 and to an input terminal Tin2 of the control unit Cnt2. When a connector Co2 provided at the end of the charging cable Ca2 is connected to a connection terminal T of the power storage device BA by a user's operation, the charger Ch2 and the power storage device BA are connected to each other, and a state is reached in which power can be supplied from the charger Ch2 to the power storage device BA.

[0046] The control unit Cnt2 is configured by, for example, a CPU or a programmable device (such as an FPGA or a PLD).

[0047] Furthermore, when the voltage input to the input terminal Tin2 drops, the control unit Cnt2 detects that the power storage device BA is connected to the charger Ch2. For example, when the voltage applied to the input terminal Tin2 becomes smaller than the voltage threshold Vth2, the control unit Cnt2 determines that the voltage applied to the input terminal Tin2 has dropped. Alternatively, the control unit Cnt2 acquires the voltage applied to the input terminal Tin2 at regular intervals, and when all voltages acquired a predetermined number of times in succession are smaller than the voltage threshold Vth2, determines that the voltage applied to the input terminal Tin2 has dropped. Here, the voltage threshold Vth2=the voltage Vd1 or the voltage Vd1'. Voltage Vd1 is the voltage applied to the connection point between voltage-dividing resistor Rd1 and voltage-dividing resistor Rd2 when charger Ch2 and power storage device BA are not connected to each other, and voltage Vd1 ≈ voltage of power supply Pc × (resistance value of voltage-dividing resistor Rd2 / (resistance value of voltage-dividing resistor Rd1 + resistance value of voltage-dividing resistor Rd2). Voltage Vd1' = voltage Vd1 - Vd1n, voltage Vd1' = voltage Vd1 × β, or voltage Vd1' = voltage Vd1 × β - Vd1n. Vd1n is a noise component included in voltage Vd1, and 0 < β < 1.

[0048] In addition, when the charger Ch2 and the storage device BA are connected to each other, a current flows from the power supply Pc to ground GND via the pull-up resistor Rp4, the voltage dividing resistor Rd1, and the voltage dividing resistor Rd2, and a current flows from the power supply Pc to ground GND via the pull-up resistor Rp4, the charging cable Ca2, the connector Co2, the connection terminal T, the Zener diode ZD1, and the resistor R4, and a current flows from the power supply Pc to ground GND via the pull-up resistor Rp4, the charging cable Ca2, the connector Co2, the connection terminal T, the resistor R2, the photodiode PD2, and the npn bipolar transistor Tr.

[0049] Furthermore, if the voltage applied to the connection point between the voltage-dividing resistor Rd1 and the voltage-dividing resistor Rd2 when the charger Ch2 and the power storage device BA are connected to each other is taken as voltage Vd2, then voltage Vd2 is approximately the total voltage applied to the Zener diode ZD1 and resistor R4 when the charger Ch2 and the power storage device BA are connected to each other × (resistance value of voltage-dividing resistor Rd2 / (resistance value of voltage-dividing resistor Rd1+resistance value of voltage-dividing resistor Rd2).

[0050] It is also assumed that the resistance values ​​of the voltage-dividing resistors Rd1, Rd2, and R4, and the breakdown voltage of the Zener diode ZD1 are set so that the voltage Vd1 is greater than the voltage Vd2.

[0051] Furthermore, when control unit Cnt2 receives a current command value transmitted from control unit Cnt via CAN communication or the like, control unit Cnt2 outputs a current according to the current command value to power storage device BA via charging cable Ca2.

[0052] <Operation of control unit Cnt when chargers Ch1, Ch2 and power storage device BA are not connected to each other>

[0053] Since the breakdown voltage of the Zener diode ZD1 is greater than the voltage of the power supply Pb, when the chargers Ch1, Ch2 and the power storage device BA are not connected to each other, no current flows from the power supply Pb to the base terminal of the npn bipolar transistor Tr via the photodiode PD1, resistor R1, backflow prevention diode D, Zener diode ZD1, and resistor R3, and the npn bipolar transistor Tr does not switch from off to on. Therefore, no current flows from the power supply Pb to the collector terminal of the npn bipolar transistor Tr via the photodiode PD1, resistor R1, backflow prevention diode D, resistor R2, and photodiode PD2. In other words, when the chargers Ch1, Ch2 and the power storage device BA are not connected to each other, no current flows through the photodiodes PD1 and PD2. Therefore, the photodiodes PD1 and PD2 do not switch from off to on, and the phototransistors PTr1 and PTr2 do not switch from off to on. In this case, for example, since the voltage applied to the input terminal Tin does not switch from voltage Vcc to voltage Vee and the voltage applied to the input terminal Tin does not become smaller than the voltage threshold value Vth, the control unit Cnt determines that the voltage input to the input terminal Tin has not decreased and detects that the chargers Ch1 and Ch2 are not connected to the storage device BA.

[0054] <Operation of control unit Cnt1 when charger Ch1 and power storage device BA are not connected to each other>

[0055] When the charger Ch1 and the power storage device BA are not connected to each other, no current flows from the power source Pb to the ground GND via the photodiode PD1, resistor R1, backflow prevention diode D, connection terminal T, connector Co1, charging cable Ca1, resistor R, and photodiode PD. That is, when the charger Ch1 and the power storage device BA are not connected to each other, no current flows through the photodiode PD. Therefore, the photodiode PD does not switch from off to on, and the phototransistor PTr does not switch from off to on. In this case, for example, the voltage applied to the input terminal Tin1 does not switch from the voltage Vcc to the voltage Vee, and the voltage applied to the input terminal Tin1 does not become smaller than the voltage threshold Vth1, so that the control unit Cnt1 determines that the voltage input to the input terminal Tin1 has not decreased, and detects that the power storage device BA is not connected to the charger Ch1.

[0056] <Operation of control unit Cnt2 when charger Ch2 and power storage device BA are not connected to each other>

[0057] When the charger Ch2 and the power storage device BA are not connected to each other, a current flows from the power source Pc to the ground GND via the pull-up resistor Rp4, the voltage dividing resistor Rd1, and the voltage dividing resistor Rd2. In this case, for example, the voltage applied to the input terminal Tin2 does not switch from the voltage Vd1 to the voltage Vd2, and the voltage applied to the input terminal Tin2 does not become smaller than the voltage threshold value Vth2, so that the control unit Cnt2 determines that the voltage input to the input terminal Tin2 has not decreased, and detects that the power storage device BA is not connected to the charger Ch2.

[0058] <Regarding the operation of control unit Cnt when charger Ch1 and power storage device BA are connected to each other and charger Ch2 and power storage device BA are not connected to each other>

[0059] When the charger Ch1 and the power storage device BA are connected to each other, a current flows from the power source Pb to the ground GND via the photodiode PD1, the resistor R1, the reverse current prevention diode D, the connection terminal T, the connector Co1, the charging cable Ca1, the resistor R, and the photodiode PD. That is, when the charger Ch1 and the power storage device BA are connected to each other, a current flows through the photodiode PD1. Therefore, the photodiode PD1 switches from off to on, and the phototransistor PTr1 switches from off to on. Then, for example, the voltage applied to the input terminal Tin drops from the voltage Vcc to the voltage Vee, and the voltage applied to the input terminal Tin becomes smaller than the voltage threshold value Vth. Therefore, the control unit Cnt determines that the voltage input to the input terminal Tin has dropped, and detects that the charger Ch1 or the charger Ch2 is connected to the power storage device BA.

[0060] <Regarding the operation of control unit Cnt when charger Ch1 and power storage device BA are not connected to each other and when charger Ch2 and power storage device BA are connected to each other>

[0061] Since the voltage of the power supply Pc is greater than the breakdown voltage of the Zener diode ZD1, when the charger Ch2 and the power storage device BA are connected to each other, a current flows from the power supply Pc to the base terminal of the npn bipolar transistor Tr via the pull-up resistor Rp4, the charging cable Ca2, the connector Co2, the connection terminal T, the Zener diode ZD1, and the resistor R3. Then, the npn bipolar transistor Tr switches from off to on, and a current flows from the power supply Pc to the collector terminal of the npn bipolar transistor Tr via the pull-up resistor Rp4, the charging cable Ca2, the connector Co2, the connection terminal T, the resistor R2, and the photodiode PD2. That is, when the charger Ch2 and the power storage device BA are connected to each other, a current flows through the photodiode PD2. Therefore, the photodiode PD2 switches from off to on, and the phototransistor PTr2 switches from off to on. Then, for example, the voltage applied to the input terminal Tin drops from voltage Vcc to voltage Vee, and the voltage applied to the input terminal Tin becomes smaller than the voltage threshold value Vth, so the control unit Cnt determines that the voltage input to the input terminal Tin has dropped and detects that the charger Ch1 or charger Ch2 has been connected to the storage device BA.

[0062] Furthermore, even if the npn bipolar transistor Tr is turned on by connecting the charger Ch2 and the storage device BA to each other, the voltage applied to the connection terminal T is greater than the voltage of the power supply Pb, so no current flows from the power supply Pb through the photodiode PD1 and resistor R1 to the backflow prevention diode D, and the photodiode PD1 does not switch from off to on.

[0063] <Regarding the operation of control unit Cnt1 when charger Ch1 and power storage device BA are connected to each other and when charger Ch2 and power storage device BA are not connected to each other>

[0064] When the charger Ch1 and the power storage device BA are connected to each other, a current flows from the power source Pb to the ground GND via the photodiode PD1, the resistor R1, the backflow prevention diode D, the connection terminal T, the connector Co1, the charging cable Ca1, the resistor R, and the photodiode PD. That is, when the charger Ch1 and the power storage device BA are connected to each other, a current flows through the photodiode PD. Therefore, the photodiode PD switches from off to on, and the phototransistor PTr switches from off to on. Then, for example, the voltage applied to the input terminal Tin1 drops from the voltage Vcc to the voltage Vee, and the voltage applied to the input terminal Tin1 becomes smaller than the voltage threshold value Vth1. Therefore, the control unit Cnt1 determines that the voltage input to the input terminal Tin1 has dropped, and the control unit Cnt1 detects that the power storage device BA is connected to the charger Ch1.

[0065] <Operation of control unit Cnt2 when charger Ch1 and power storage device BA are not connected to each other and when charger Ch2 and power storage device BA are connected to each other>

[0066] When the charger Ch2 and the power storage device BA are connected to each other, the current output from the power source Pc flows not only through the voltage dividing resistors Rd1 and Rd2 but also through the Zener diode ZD1 and resistor R4. Then, for example, the voltage applied to the input terminal Tin2 drops from the voltage Vd1 to the voltage Vd2, and the voltage applied to the input terminal Tin2 becomes smaller than the voltage threshold value Vth2. Therefore, the control unit Cnt2 determines that the voltage input to the input terminal Tin2 has dropped, and detects that the power storage device BA is connected to the charger Ch2.

[0067] In this way, the charger connection detection circuit 1 of the embodiment can detect whether the charger Ch1, which performs connection detection using the power source Pb on the power storage device BA side, or the charger Ch2, which performs connection detection using the power source Pc on the charger Ch2 side, is connected to the power storage device BA. Also, the charger connection detection circuit 1 of the embodiment can cause the charger Ch1 to detect whether the power storage device BA is connected to the charger Ch1, and can cause the charger Ch2 to detect whether the power storage device BA is connected to the charger Ch2. That is, the charger connection detection circuit 1 of the embodiment can detect whether the chargers Ch1, Ch2 and the power storage device BA are connected to each other on the chargers Ch1, Ch2 side and the power storage device BA side, respectively, even if the connection detection specifications (methods) of the chargers Ch1, Ch2 are different from each other.

[0068] Furthermore, according to the charger connection detection circuit 1 of the embodiment, the connection terminal T side and the control unit Cnt side can be insulated by the photocouplers PC1 and PC2, so that even if a relatively high voltage is applied to the control unit Cnt side, a relatively high voltage can be prevented from being applied to the connection terminal T side.

[0069] The present invention is not limited to the above-described embodiment, and various improvements and modifications are possible without departing from the gist of the present invention.

[0070] <Variation 1> Fig. 2 is a diagram showing a first modified example of the charger connection detection circuit of the embodiment. In Fig. 2, the same components as those shown in Fig. 1 are given the same reference numerals, and the description thereof will be omitted. In Fig. 2, the operations of the control units Cnt, Cnt1, and Cnt2 when the chargers Ch1 and Ch2 and the power storage device BA are not connected to each other, the operation of the control unit Cnt1 when the charger Ch1 and the power storage device BA are connected to each other, and the operation of the control unit Cnt2 when the charger Ch2 and the power storage device BA are connected to each other are similar to the operations of the control units Cnt, Cnt1, and Cnt2 shown in Fig. 1, and therefore the description thereof will be omitted.

[0071] The charger connection detection circuit 1 shown in FIG. 2 differs from the charger connection detection circuit 1 shown in FIG. 1 in that the control unit Cnt includes an input terminal Tin11 (first input terminal) and an input terminal Tin12 (second input terminal).

[0072] The input terminal Tin11 is connected to the connection point between the pull-up resistor Rp1 and the collector terminal of the phototransistor PTr1, and the input terminal Tin12 is connected to the connection point between the pull-up resistor Rp2 and the collector terminal of the phototransistor PTr2.

[0073] When the voltage input to the input terminal Tin11 drops, the control unit Cnt detects that the charger Ch1 is connected to the power storage device BA. For example, when the voltage applied to the input terminal Tin11 is lower than a voltage threshold Vth, the control unit Cnt determines that the voltage input to the input terminal Tin11 has dropped. Alternatively, the control unit Cnt acquires the voltage applied to the input terminal Tin11 at regular intervals, and when all voltages acquired a predetermined number of times in succession are lower than the voltage threshold Vth, the control unit Cnt determines that the voltage input to the input terminal Tin11 has dropped.

[0074] Furthermore, when the voltage input to the input terminal Tin12 drops, the control unit Cnt detects that the charger Ch2 is connected to the power storage device BA. For example, when the voltage applied to the input terminal Tin12 is lower than the voltage threshold Vth, the control unit Cnt determines that the voltage applied to the input terminal Tin12 has dropped. Alternatively, the control unit Cnt acquires the voltage applied to the input terminal Tin12 at regular intervals, and when all voltages acquired a predetermined number of times in succession are lower than the voltage threshold Vth, the control unit Cnt determines that the voltage applied to the input terminal Tin12 has dropped.

[0075] <Regarding the operation of control unit Cnt when charger Ch1 and power storage device BA are connected to each other and charger Ch2 and power storage device BA are not connected to each other>

[0076] When the charger Ch1 and the power storage device BA are connected to each other, a current flows through the photodiode PD1, the photodiode PD1 switches from off to on, and the phototransistor PTr1 switches from off to on. Also, since the charger Ch2 and the power storage device BA are not connected to each other, a current does not flow through the photodiode PD2, the photodiode PD2 does not switch from off to on, and the phototransistor PTr2 does not switch from off to on. In this case, for example, the voltage applied to the input terminal Tin11 drops from the voltage Vcc to the voltage Vee, and the voltage applied to the input terminal Tin12 is maintained at the voltage Vcc. Therefore, the control unit Cnt determines that the voltage input to the input terminal Tin11 has dropped and that the voltage input to the input terminal Tin12 has not dropped, and detects that the charger Ch1 is connected to the power storage device BA and detects that the charger Ch2 is not connected to the power storage device BA.

[0077] <Regarding the operation of control unit Cnt when charger Ch1 and power storage device BA are not connected to each other and when charger Ch2 and power storage device BA are connected to each other>

[0078] When the charger Ch2 and the power storage device BA are connected to each other, the Zener diode ZD1 is switched from off to on, so that a current flows through the photodiode PD2, the photodiode PD2 is switched from off to on, and the phototransistor PTr2 is switched from off to on. Also, since the charger Ch1 and the power storage device BA are not connected to each other, no current flows through the photodiode PD1, the photodiode PD1 is not switched from off to on, and the phototransistor PTr1 is not switched from off to on. In this case, for example, the voltage applied to the input terminal Tin12 drops from the voltage Vcc to the voltage Vee, and the voltage applied to the input terminal Tin11 is maintained at the voltage Vcc. Therefore, the control unit Cnt determines that the voltage input to the input terminal Tin12 has dropped, and determines that the voltage input to the input terminal Tin11 has not dropped, and detects that the charger Ch2 is connected to the power storage device BA, and detects that the charger Ch1 is not connected to the power storage device BA.

[0079] According to the charger connection detection circuit 1 shown in FIG. 2, similarly to the charger connection detection circuit 1 shown in FIG. 1, even if the connection detection specifications (methods) of the chargers Ch1, Ch2 are different from each other, it is possible for the chargers Ch1, Ch2 side and the power storage device BA side to respectively detect whether the chargers Ch1, Ch2 and the power storage device BA are connected to each other.

[0080] 2, the charger connection detection circuit 1 can identify (distinguish) the charger Ch1 or charger Ch2 as the charger connected to the power storage device BA. Therefore, it is not necessary to identify the charger Ch1 or Ch2 using CAN communication or the like in preparation for charging the battery, and the configuration for preparation for charging can be simplified accordingly.

[0081] <Variation 2> Fig. 3 is a diagram showing a modified example 2 of the charger connection detection circuit 1 of the embodiment. In Fig. 3, the same components as those shown in Fig. 1 are denoted by the same reference numerals, and the description thereof will be omitted. In Fig. 3, the operations of the control units Cnt, Cnt1, and Cnt2 when the chargers Ch1 and Ch2 and the power storage device BA are not connected to each other, the operations of the control units Cnt and Cnt1 when the charger Ch1 and the power storage device BA are connected to each other, and the operations of the control units Cnt and Cnt2 when the charger Ch2 and the power storage device BA are connected to each other are similar to the operations of the control units Cnt, Cnt1, and Cnt2 shown in Fig. 1, and therefore the description thereof will be omitted.

[0082] The charger connection detection circuit 1 shown in Fig. 3 differs from the charger connection detection circuit 1 shown in Fig. 1 in that it further includes a Zener diode ZD2 (second Zener diode), a switch SW, and resistors R5 and R6. The breakdown voltage of the Zener diode ZD2 is lower than the voltage of the power supply Pc and the breakdown voltage of the Zener diode ZD1. The switch SW is, for example, an n-channel MOSFET (Metal Oxide Semiconductor Field Effect Transistor).

[0083] The cathode terminal of the Zener diode ZD2 is connected to the cathode terminal of the Zener diode ZD1, and the anode terminal of the Zener diode ZD2 is connected to the drain terminal of the switch SW. The source terminal of the switch SW is connected to the anode terminal of the Zener diode ZD1, and the gate terminal of the switch SW is connected to ground GND via a resistor R5 and to the control unit Cnt via a resistor R6.

[0084] The control unit Cnt detects that the charger Ch2 is connected to the power storage device BA by identifying the charger Ch2 as the charger connected to the power storage device BA through CAN communication or the like, and then, when preparation for charging the battery is complete, switches the switch SW from off (disconnected state) to on (conductive state) by applying a voltage to the gate terminal of the switch SW via resistor R6.

[0085] Since the breakdown voltage of the Zener diode ZD2 is smaller than the voltage of the power supply Pc and the breakdown voltage of the Zener diode ZD1, when the switch SW is switched from off to on while the charger Ch2 and the power storage device BA are connected to each other, the current flowing from the power supply Pc to the Zener diode ZD1 through the charging cable Ca2 flows to the Zener diode ZD2. Therefore, even if the switch SW is switched from off to on, the npn bipolar transistor Tr continues to be in the on state. Also, since the breakdown voltage of the Zener diode ZD2 is smaller than the breakdown voltage of the Zener diode ZD1, when the switch SW is switched from off to on, the voltage applied to the charging cable Ca2 drops from the total voltage applied to the Zener diode ZD1 and the resistor R4 to the total voltage applied to the Zener diode ZD2 and the resistor R4, and the voltage applied to the input terminal Tin2 drops. As a result, after detecting that the power storage device BA is connected to the charger Ch2, the control unit Cnt2 of the charger Ch2 can determine that the battery is ready to be charged when the voltage input to the input terminal Tin2 drops.

[0086] According to the charger connection detection circuit 1 shown in FIG. 3, similarly to the charger connection detection circuit 1 shown in FIG. 1, even if the connection detection specifications (methods) of the chargers Ch1, Ch2 are different from each other, it is possible for the chargers Ch1, Ch2 side and the power storage device BA side to respectively detect whether the chargers Ch1, Ch2 and the power storage device BA are connected to each other.

[0087] Furthermore, the charger connection detection circuit 1 shown in FIG. 3 can notify the charger Ch2 side from the power storage device BA side that preparations for charging the battery are complete by changing the voltage applied to the charging cable Ca2.

[0088] The charger connection detection circuit 1 shown in FIG. 3 may be applied to the charger connection detection circuit 1 shown in FIG.

[0089] <Modification 3> Fig. 4 is a diagram showing a third modified example of the charger connection detection circuit 1 of the embodiment. In Fig. 4, the same components as those shown in Fig. 1 are denoted by the same reference numerals, and the description thereof will be omitted. In Fig. 4, the operations of the control units Cnt, Cnt1, and Cnt2 when the chargers Ch1 and Ch2 and the power storage device BA are not connected to each other, the operations of the control units Cnt and Cnt1 when the charger Ch1 and the power storage device BA are connected to each other, and the operations of the control units Cnt and Cnt2 when the charger Ch2 and the power storage device BA are connected to each other are similar to the operations of the control units Cnt, Cnt1, and Cnt2 shown in Fig. 1, and therefore the description thereof will be omitted.

[0090] The charger connection detection circuit 1 shown in FIG. 4 differs from the charger connection detection circuit 1 shown in FIG. 1 in that it further includes a voltage dividing resistor Rd3 (first voltage dividing resistor) and a voltage dividing resistor Rd4 (second voltage dividing resistor).

[0091] One terminal of the voltage-dividing resistor Rd3 is connected to the connection terminal T, and the other terminal of the voltage-dividing resistor Rd3 is connected to the ground GND via the voltage-dividing resistor Rd4, and the voltage applied to the connection point of the voltage-dividing resistors Rd3 and Rd4 is input to the control unit Cnt.

[0092] When the voltage applied to the connection point of the voltage-dividing resistors Rd3 and Rd4 is greater than the upper limit Vmax, or when the voltage applied to the connection point of the voltage-dividing resistors Rd3 and Rd4 is less than the lower limit Vmin which is less than the upper limit Vmax, that is, when the voltage applied to the connection point of the voltage-dividing resistors Rd3 and Rd4 does not fall within the fluctuation range of the voltage applied to the connection point of the voltage-dividing resistors Rd3 and Rd4 when no failure occurs in the charger connection detection circuit 1, the charger Ch1, and the charger Ch2, the control unit Cnt determines that a failure has occurred in at least one of the charger connection detection circuit 1, the charger Ch1, and the charger Ch2. For example, the upper limit Vmax is set to the voltage applied to the connection point of the voltage-dividing resistors Rd3 and Rd4 when no failure occurs in the charger connection detection circuit 1 and the charger Ch2 and when the charger Ch2 and the power storage device BA are connected to each other. Further, the lower limit value Vmin is the voltage applied to the connection point of the voltage-dividing resistors Rd3 and Rd4 when no failure occurs in the charger connection detection circuit 1 and the charger Ch1 and when the charger Ch1 and the power storage device BA are connected to each other.

[0093] According to the charger connection detection circuit 1 shown in FIG. 4, similarly to the charger connection detection circuit 1 shown in FIG. 1, even if the connection detection specifications (methods) of the chargers Ch1, Ch2 are different from each other, it is possible to detect whether the chargers Ch1, Ch2 and the power storage device BA are connected to each other on the charger connection detection circuit side and on the power storage device BA side.

[0094] In addition, according to the charger connection detection circuit 1 shown in FIG. 4, it is possible to determine that a fault has occurred in at least one of the charger connection detection circuit 1, charger Ch1, and charger Ch2 (for example, a fault in which an overvoltage greater than the voltage of the power source Pc is applied to the connection terminal T, or a fault in which the connection terminal T is short-circuited to ground GND, etc.), so that the user can be notified that a fault has occurred in at least one of the charger connection detection circuit 1, charger Ch1, and charger Ch2, and early recovery from the fault can be achieved.

[0095] The charger connection detection circuit 1 shown in FIG. 4 may be applied to the charger connection detection circuit 1 shown in FIG. 2 or the charger connection detection circuit 1 shown in FIG.

[0096] <Variation 4> In the charger connection detection circuit 1 shown in Figures 1 to 4, photocouplers PC1, PC2 and pull-up resistors Rp1, Rp2 are used as a circuit configuration for reducing the voltage input to the input terminals Tin, Tin11, Tin12 when the charger Ch1 or charger Ch2 and the power storage device BA are connected to each other, but the circuit configuration is not particularly limited as long as it is possible to reduce the voltage input to the input terminals Tin, Tin11, Tin12 when the charger Ch1 or charger Ch2 and the power storage device BA are connected to each other. [Explanation of symbols]

[0097] 1 Charger connection detection circuit BA Energy Storage Device T Connection Terminal PC1, PC2, PC Photocoupler P, Pb, Pc power supply Rp1~Rp4 Pull-up resistors R1~R6, R resistance D Reverse current prevention diode ZD1, ZD2 Zener diode Tr npn bipolar transistor Ch1, Ch2 charger Rd1~Rd4 Voltage divider resistors Cnt, Cnt1, Cnt2 control section Ca1, Ca2 charging cable Co1, Co2 connector SW Switch

Claims

1. A charger connection detection circuit provided in a power storage device, A power storage device side power supply; A control unit having an input terminal; a first photocoupler and a second photocoupler that, when switched from off to on, reduces a voltage input to the input terminal; Equipped with The control unit detects that the first charger or the second charger is connected to the power storage device when a current flows from the power storage device side power supply to the first charger via the first photocoupler, causing the first photocoupler to switch from off to on and a voltage input to the input terminal to drop, or when a current flows from the charger side power supply provided in the second charger to the second photocoupler, causing the second photocoupler to switch from off to on and a voltage input to the input terminal to drop. Charger connection detection circuit.

2. 2. The charger connection detection circuit according to claim 1, the input terminals include first and second input terminals; The control unit is When the first photocoupler is switched from off to on and the voltage input to the first input terminal is reduced, the first charger detects that it is connected to the power storage device; When the second photocoupler switches from off to on and the voltage input to the second input terminal drops, it is detected that the second charger is connected to the power storage device. Charger connection detection circuit.

3. 2. The charger connection detection circuit according to claim 1, a connection terminal connectable to a charging cable provided in the first charger or the second charger; a first photodiode provided in the first photocoupler, the first photodiode having an anode terminal connected to the power storage device side power supply; a first phototransistor provided in the first photocoupler, the first phototransistor being switched from off to on when the first photodiode is switched from off to on, thereby reducing a voltage input to the input terminal; a reverse current prevention diode having a cathode terminal connected to the connection terminal and an anode terminal connected to the cathode terminal of the first photodiode via a first resistor; a second photodiode provided in the second photocoupler, the second photodiode having an anode terminal connected to the connection terminal via a second resistor; a second phototransistor provided in the second photocoupler, the second phototransistor being switched from off to on when the second photodiode is switched from off to on, thereby reducing a voltage input to the input terminal; an npn bipolar transistor having a collector terminal connected to the cathode terminal of the second photodiode, an emitter terminal connected to ground, and a base terminal connected to the ground via a third resistor and a fourth resistor; a first Zener diode having a cathode terminal connected to a connection point between the connection terminal and the second resistor and an anode terminal connected to a connection point between the third resistor and the fourth resistor; Equipped with The control unit detects that the first charger or the second charger is connected to the power storage device when a current flows from the power storage device-side power supply to the first charger via the first photodiode, the first resistor, the reverse current prevention diode, the connection terminal, and the first charging cable, causing the first photodiode to switch from off to on and a voltage input to the input terminal to drop, or when a current flows from the charger-side power supply to the base terminal of the npn bipolar transistor via the second charging cable, the connection terminal, the first Zener diode, and the third resistor, causing the npn bipolar transistor to switch from off to on, and then a current flows from the charger-side power supply to the collector terminal of the npn bipolar transistor via the second charging cable, the connection terminal, the second resistor, and the second photodiode, causing the second photodiode to switch from off to on and a voltage input to the input terminal to drop. Charger connection detection circuit.

4. 4. The charger connection detection circuit according to claim 3, a second Zener diode having a cathode terminal connected to the cathode terminal of the first Zener diode and an anode terminal connected to the anode terminal of the first Zener diode via a switch, the second Zener diode having a breakdown voltage lower than that of the first Zener diode; When the control unit detects that the second charger is connected to the power storage device and then completes preparation for charging the battery included in the power storage device, the control unit switches the switch from a cut-off state to a conductive state, thereby causing the current flowing from the charger-side power supply to the first Zener diode to flow to the second Zener diode, thereby maintaining the on state of the npn bipolar transistor. Charger connection detection circuit.

5. 5. The charger connection detection circuit according to claim 3, further comprising: a first voltage dividing resistor and a second voltage dividing resistor connected between the connection terminal and the ground; The control unit determines that a failure has occurred in at least one of the charger connection detection circuit, the first charger, and the second charger when a voltage applied to a connection point between the first voltage dividing resistor and the second voltage dividing resistor is greater than an upper limit value, or when a voltage applied to a connection point between the first voltage dividing resistor and the second voltage dividing resistor is smaller than a lower limit value that is smaller than the upper limit value. Charger connection detection circuit.

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