charger

Abstract

To suppress an increase of a charging time of a battery while suppressing deterioration or failures in a storage battery, an AC / DC conversion circuit and a DC / DC conversion circuit provided in a charger.SOLUTION: In a case where it is determined that it is not necessary to limit output of an AC / DC conversion circuit 4 and in a case where it is determined that it is necessary to limit output of a storage battery Bc or a DC / DC conversion circuit 5, limitation sub output is outputted from the DC / DC conversion circuit 5, and supplement main output is outputted from the AC / DC conversion circuit 4. In a case where it is determined that it is necessary to limit the output of the AC / DC conversion circuit 4 and in a case where it is determined that it is not necessary to limit the output of the storage battery Bc and the DC / DC conversion circuit 5, limitation main output is outputted from the AC / DC conversion circuit 4, and supplement sub output is outputted from the DC / DC conversion circuit 5.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a charger. [Background technology]

[0002] There is a charger that includes a storage battery, an AC / DC conversion circuit that converts AC power supplied from a power source into DC power and outputs it to a battery or a storage battery, and a DC / DC conversion circuit that converts DC power supplied from the storage battery into a predetermined DC power and outputs it to the battery, and outputs a part of the power required from the battery from the AC / DC conversion circuit and the remainder from the DC / DC conversion circuit.

[0003] Generally, there is a suitable range for the charge rate (the ratio of remaining capacity to the full charge capacity) and temperature of a storage battery, and using the storage battery beyond that range may lead to deterioration or failure of the storage battery, making it difficult to output the desired power from the storage battery. Therefore, it is conceivable to suppress the temperature rise of the storage battery by, for example, limiting the output power of the storage battery in accordance with the rise in the charge rate or temperature of the storage battery.

[0004] Furthermore, if the temperature of components (such as switching elements) constituting the AC / DC conversion circuit or DC / DC conversion circuit is relatively high, this may lead to deterioration or failure of the components, making it difficult to output desired power from the AC / DC conversion circuit or DC / DC conversion circuit. Therefore, it is conceivable to suppress the temperature rise of the components constituting the AC / DC conversion circuit or DC / DC conversion circuit by limiting the output power of the AC / DC conversion circuit or DC / DC conversion circuit in accordance with the rise in temperature of the components constituting the AC / DC conversion circuit or DC / DC conversion circuit.

[0005] However, in the above-mentioned charger, if the output power of at least one of the storage battery, the AC / DC conversion circuit, and the DC / DC conversion circuit is limited, the power output from the charger may fall short of the power required by the battery, and the charging time for the battery may increase. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 5-111171 Summary of the Invention [Problem to be solved by the invention]

[0007] An object of one aspect of the present invention is to suppress an increase in battery charging time while suppressing deterioration and failure of the storage battery, AC / DC conversion circuit, and DC / DC conversion circuit in a charger equipped with a storage battery, an AC / DC conversion circuit, and a DC / DC conversion circuit. [Means for solving the problem]

[0008] A charger according to one embodiment of the present invention is a charger that supplies power to a battery and includes a storage battery, an AC / DC conversion circuit that converts AC power supplied from a power source into DC power and outputs it to the battery or the storage battery, a DC / DC conversion circuit that converts the DC power supplied from the storage battery into a predetermined DC power and outputs it to the battery, and a control circuit that controls the operation of the AC / DC conversion circuit and the DC / DC conversion circuit.

[0009] When it is determined that there is no need to limit the outputs of the storage battery, the AC / DC conversion circuit, and the DC / DC conversion circuit, the control circuit controls operation of the AC / DC conversion circuit so that a primary output is output from the AC / DC conversion circuit, and controls operation of the DC / DC conversion circuit so that a secondary output obtained by subtracting the primary output from an output required from the battery is output from the DC / DC conversion circuit; when it is determined that there is no need to limit the output of the AC / DC conversion circuit and it is necessary to limit the output of the storage battery or the DC / DC conversion circuit, the control circuit controls operation of the AC / DC conversion circuit so that a secondary output obtained by subtracting the primary output from an output required from the battery is output from the DC / DC conversion circuit. and controls the operation of the AC / DC conversion circuit so that a limited main output is output from the AC / DC conversion circuit, and controls the operation of the AC / DC conversion circuit so that a supplementary main output obtained by increasing the main output is output from the AC / DC conversion circuit, and when it is determined that it is necessary to limit the output of the AC / DC conversion circuit and when it is determined that it is not necessary to limit the outputs of the storage battery and the DC / DC conversion circuit, it controls the operation of the AC / DC conversion circuit so that a limited main output is output from the AC / DC conversion circuit, and controls the operation of the DC / DC conversion circuit so that a supplementary secondary output obtained by increasing the secondary output is output from the DC / DC conversion circuit.

[0010] As a result, when it is possible to compensate for at least a part of the limited amount of the limited secondary output of the storage battery or DC / DC conversion circuit with an increase in the compensation main output of the AC / DC conversion circuit, it is possible to bring the output of the charger closer to the output required by the battery while limiting the output of the storage battery or DC / DC conversion circuit. Also, when it is possible to compensate for at least a part of the limited amount of the limited primary output of the AC / DC conversion circuit with an increase in the compensation secondary output of the DC / DC conversion circuit, it is possible to bring the output of the charger closer to the output required by the battery while limiting the output of the AC / DC conversion circuit. Therefore, it is possible to suppress an increase in the charging time of the battery while suppressing the occurrence of deterioration and failure of the storage battery, AC / DC conversion circuit, and DC / DC conversion circuit.

[0011] In addition, the control circuit may be configured to control the operation of the AC / DC conversion circuit so that the increased compensation main output is output from AC / DC conversion circuit 4 when it is determined that there is no need to limit the output of the AC / DC conversion circuit, when it is determined that there is a need to limit the output of the storage battery or the DC / DC conversion circuit, when the current output of the charger is smaller than the output required from the battery, and when the compensation main output is smaller than the maximum output of the AC / DC conversion circuit.

[0012] In addition, the control circuit may be configured to control the operation of the DC / DC conversion circuit so that the increased compensation secondary output is output from the DC / DC conversion circuit when it is determined that it is necessary to limit the output of the AC / DC conversion circuit, when it is determined that there is no need to limit the output of the storage battery or the DC / DC conversion circuit, when the current output of the charger is smaller than the required output from the battery, and when the compensation secondary output is smaller than the current maximum output of the DC / DC conversion circuit.

[0013] The control circuit may also be configured to control the operation of the AC / DC conversion circuit so that the supplementary main output is continuously output from the AC / DC conversion circuit when it is determined that there is no need to limit the output of the AC / DC conversion circuit, when it is determined that there is a need to limit the output of the storage battery or the DC / DC conversion circuit, when the current output of the charger is smaller than the required output from the battery, and when the supplementary main output is equal to or greater than the maximum output of the AC / DC conversion circuit.

[0014] The control circuit may also be configured to control the operation of the DC / DC conversion circuit so that the compensation secondary output continues to be output from the DC / DC conversion circuit when it is determined that it is necessary to limit the output of the AC / DC conversion circuit, when it is determined that there is no need to limit the outputs of the storage battery and the DC / DC conversion circuit, when the current output of the charger is smaller than the required output from the battery, and when the compensation secondary output is equal to or greater than the maximum output of the DC / DC conversion circuit.

[0015] The control circuit may be configured to determine that it is necessary to limit the output of the storage battery when the positive temperature of the storage battery is within a range from a first high temperature threshold to a first rated upper limit temperature higher than the first high temperature threshold, or when the negative temperature of the storage battery is within a range from a first low temperature threshold to a first rated lower limit temperature lower than the first low temperature threshold; to determine that it is necessary to limit the output of the DC / DC conversion circuit when the positive temperature of a component constituting the DC / DC conversion circuit is within a range from a second high temperature threshold to a second rated upper limit temperature higher than the second high temperature threshold, or when the negative temperature of a component constituting the DC / DC conversion circuit is within a range from a second low temperature threshold to a second rated lower limit temperature lower than the second low temperature threshold; and to determine that it is necessary to limit the output of the AC / DC conversion circuit when the positive temperature of a component constituting the AC / DC conversion circuit is within a range from a third high temperature threshold to a third rated upper limit temperature higher than the third high temperature threshold, or when the negative temperature of a component constituting the AC / DC conversion circuit is within a range from a third low temperature threshold to a third rated lower limit temperature lower than the third low temperature threshold.

[0016] The control circuit may be configured to stop the AC / DC conversion circuit and the DC / DC conversion circuit when the positive temperature of the storage battery is higher than the first rated upper limit temperature, when the negative temperature of the storage battery is lower than the first rated lower limit temperature, when the positive temperature of a component constituting the DC / DC conversion circuit is higher than the second rated upper limit temperature, when the negative temperature of a component constituting the DC / DC conversion circuit is lower than the second rated lower limit temperature, when the positive temperature of a component constituting the AC / DC conversion circuit is higher than the third rated upper limit temperature, or when the negative temperature of a component constituting the AC / DC conversion circuit is lower than the third rated lower limit temperature.

[0017] The output voltage of the charger may be set to 120 V or less.

[0018] The output current of the charger may be set to 75 to 195 [A].

[0019] The charger may be mounted on a vehicle, and the vehicle may be an industrial vehicle. Effect of the Invention

[0020] According to the present invention, in a charger equipped with a storage battery, an AC / DC conversion circuit, and a DC / DC conversion circuit, it is possible to suppress an increase in the charging time of the battery while suppressing deterioration and failure of the storage battery, the AC / DC conversion circuit, and the DC / DC conversion circuit. [Brief description of the drawings]

[0021] [Figure 1] FIG. 2 is a diagram showing a charger according to an embodiment. [Diagram 2] 2 is a diagram illustrating an example of a power storage device, an AC / DC conversion circuit, and a DC / DC conversion circuit. [Diagram 3] FIG. 4 is a diagram for explaining constant-current constant-voltage charging control. [Figure 4]11A and 11B are diagrams illustrating an example of information showing the relationship between the temperature of a storage battery and the maximum output of the storage battery for each charging rate of the storage battery, information showing the relationship between the temperature of components constituting a DC / DC conversion circuit and the maximum output of the DC / DC conversion circuit, and information showing the relationship between the temperature of components constituting an ADC / DC conversion circuit and the maximum output of the AC / DC conversion circuit. [Diagram 5] 10 is a flowchart showing an example of an operation of a control unit. [Figure 6] 5 is a flowchart showing an example of an operation of a control unit during output limiting charging control of a DC / DC conversion circuit. [Figure 7] 5 is a flowchart showing an example of an operation of a control unit during output limiting charging control of an AC / DC conversion circuit. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] Hereinafter, the embodiments will be described in detail with reference to the drawings.

[0023] FIG. 1 is a diagram showing a charger according to an embodiment.

[0024] 1 supplies power to a power storage device 2 mounted on a vehicle Ve, and includes a power storage device 3, an AC / DC conversion circuit 4, a DC / DC conversion circuit 5, and a control circuit 6. The vehicle Ve is an industrial vehicle such as a forklift, or an electric vehicle. The power storage device 2 includes a battery Bv that supplies power to loads such as a loading device and a traveling motor mounted on the vehicle Ve. When the vehicle Ve is an industrial vehicle, the output voltage of the charger 1 is set to, for example, 120 [V] or less, and the output current of the charger 1 is set to 75 [A] to 195 [A].

[0025] The power storage device 3 includes a storage battery Bc. Although the power storage device 3 is configured to be provided outside the charger 1 in FIG.

[0026] The AC / DC conversion circuit 4 converts AC power supplied from the system power supply P into DC power and outputs it to the battery Bv or the storage battery Bc.

[0027] The DC / DC conversion circuit 5 converts the DC power supplied from the storage battery Bc into a predetermined DC power and outputs it to the battery Bv.

[0028] The control circuit 6 controls the operation of the AC / DC conversion circuit 4 and the DC / DC conversion circuit 5 so that the required output Pt from the battery Bv is output from the charger 1. The required output Pt is the power, voltage, or current (command current) required from the battery Bv. In other words, the control circuit 6 controls the operation of the AC / DC conversion circuit 4 and the DC / DC conversion circuit 5 not only based on the required power, but also based on the required current and required voltage.

[0029] Fig. 2 is a diagram showing an example of the power storage device 2, the power storage device 3, the AC / DC conversion circuit 4, and the DC / DC conversion circuit 5. Note that the circuit configurations of the AC / DC conversion circuit 4 and the DC / DC conversion circuit 5 shown in Fig. 2 are merely examples and are not particularly limited.

[0030] <Regarding the Power Storage Device 2> The power storage device 2 includes a battery Bv, a current detection unit Si, a voltage detection unit Sv, and a control unit Cntv.

[0031] The battery Bv is, for example, a lithium ion secondary battery, a nickel-metal hydride battery, or a lead storage battery.

[0032] The current detection unit Si is configured with, for example, a Hall element or a shunt resistor, detects a current I flowing through the battery Bv, and sends the detected current I to the control unit Cntv.

[0033] The voltage detection unit Sv is configured, for example, with a plurality of voltage dividing resistors connected in series with each other, detects the voltage V of the battery Bv, and sends the detected voltage V to the control unit Cntv.

[0034] The control unit Cntv is configured by, for example, a processor or a programmable device (such as a field programmable gate array (FPGA) or a programmable logic device (PLD)), and controls charging and discharging of the battery Bv.

[0035] Furthermore, the control unit Cntv obtains the charging rate SOCv of the battery Bv (the ratio of the remaining capacity of the battery Bv to the full charge capacity of the battery Bv) during or after the discharge of the battery Bv, and displays the obtained charging rate SOCv on a display (not shown) or the like. For example, the control unit Cntv refers to information indicating the correspondence between the open circuit voltage of the battery Bv and the charging rate SOCv, and estimates the charging rate SOCv corresponding to the open circuit voltage of the battery Bv estimated from the voltage V as the charging rate SOCv during or after the discharge is completed. Alternatively, the control unit Cntv sets the charging rate SOCv calculated by the following formula 1 as the charging rate SOCv of the battery Bv during or after the discharge is completed.

[0036] Charging rate SOCv = Charging rate SOCv at the start of discharge + (integrated value of current I flowing through battery Bv from the start of discharge to the present / full charge capacity of battery Bv) × 100 ··· Equation 1 Furthermore, when the charger 1 and the power storage device 2 are connected to each other via a charging cable (not shown) and a command to start charging the battery Bv is input by a user or the like, the control unit Cntv starts the constant-current constant-voltage charging control. Note that when the charger 1 and the power storage device 2 are connected to each other via a charging cable, the constant-current constant-voltage charging control may be started automatically.

[0037] <Constant current / constant voltage charging control> FIG. 3 is a diagram for explaining constant current constant voltage charging control. In addition, the horizontal axis of the two-dimensional coordinate shown in FIG. 3(a) indicates time, and the vertical axis indicates current. In addition, the solid line shown in FIG. 3(a) typically indicates the current Iv flowing through the battery Bv. In addition, the horizontal axis of the two-dimensional coordinate shown in FIG. 3(b) indicates time, and the vertical axis indicates voltage. In addition, the solid line shown in FIG. 3(b) typically indicates the voltage Vv of the battery Bv. In addition, the current Iv shown in FIG. 3(a) and the voltage Vv shown in FIG. 3(b) are the current Iv and voltage Vv when there is no restriction on the output power of each of the storage battery Bc, the AC / DC conversion circuit 4, and the DC / DC conversion circuit 5. In addition, time t0<time t1<time t2.

[0038] First, when the control unit Cntv starts charging control, it transmits a command current equivalent to the constant current Ic shown in Fig. 3(a) to the control circuit 6 by CAN (Controller Area Network) communication or the like. Then, as shown in Fig. 3(a), the constant current Ic flows to the battery Bv after time t0, and as shown in Fig. 3(b), the voltage Vv of the battery Bv gradually increases after time t0. Note that charging control that charges the battery Bv while keeping the current Iv flowing to the battery Bv constant is called constant current charging control.

[0039] Next, as shown in Fig. 3(b), when the voltage Vv of the battery Bv becomes equal to or higher than the constant voltage Vc at time t1, the control unit Cntv gradually reduces the command current so that the current Iv flowing to the battery Bv gradually decreases while the voltage Vv of the battery Bv is maintained at the constant voltage Vc as shown in Fig. 3(b). Then, as shown in Fig. 3(a), the current Iv flowing to the battery Bv gradually decreases after time t1 while the voltage Vv of the battery Bv is maintained at the constant voltage Vc as shown in Fig. 3(b).

[0040] Then, as shown in FIG. 3(a), at time t2, when the current Iv flowing through the battery Bv becomes equal to or less than the termination current If, the control unit Cntv terminates the charging control by setting the command current to zero and sets the charging rate SOCv of the battery Bv to 100%.

[0041] In the charger 1 of the embodiment, the power output from the system power supply P and the storage battery Bc (AC / DC conversion circuit 4 and DC / DC conversion circuit 5) is supplied to the battery Bv, so the constant current Ic can be made larger than in a configuration in which only the power output from the system power supply P (AC / DC conversion circuit 4) is supplied to the battery Bv. This makes it possible to shorten the time required to increase the voltage Vv of the battery Bv to the constant voltage Vc, and therefore to shorten the charging time of the battery Bv. In other words, in the charger 1 of the embodiment, rapid charging can be performed using the power output from the system power supply P and the storage battery Bc, so the charging time of the battery Bv can be made relatively short.

[0042] The control unit Cntv may be configured to transmit a command current equivalent to the constant current Ic to the control circuit 6 after time t0 when the charging control starts, and to terminate the charging control by setting the command current to zero when the voltage Vv of the battery Bv becomes equal to or higher than the constant voltage Vc at time t1, and to set the charging rate SOCv of the battery Bv to 100%. By configuring in this way, the charging time of the battery Bv can be further shortened.

[0043] In addition, rapid charging may be defined as a case in which a current of 195 [A] is passed through battery Bv, which is a lithium-ion secondary battery with a capacity of 456 [Ah / 5Hr], and the operation of the AC / DC conversion circuit 4 and DC / DC conversion circuit 5 is controlled so that the time it takes for the charging rate SOCv of battery Bv to increase from 20 [%] to 100 [%] is 2 hours and 25 minutes.

[0044] <Regarding the Power Storage Device 3> The power storage device 3 shown in FIG. 2 includes a storage battery Bc, a temperature detection unit St1, a current detection unit Si1, a voltage detection unit Sv1, and a control unit Cntc.

[0045] The storage battery Bc is, for example, a lithium ion secondary battery, a nickel-metal hydride battery, or a lead storage battery.

[0046] The temperature detection unit St1 is composed of, for example, a thermistor, etc., detects the temperature of the storage battery Bc, and sends the detected temperature to the control circuit 6 via the control unit Cntc.

[0047] The current detection unit Si1 is composed of, for example, a Hall element or a shunt resistor, etc., detects the current I1 flowing through the storage battery Bc, and sends the detected current I1 to the control unit Cntc.

[0048] The voltage detection unit Sv1 is composed of, for example, a plurality of voltage dividing resistors connected in series with each other, etc., detects the voltage V1 of the storage battery Bc, and sends the detected voltage V1 to the control unit Cntv.

[0049] The control unit Cntc is composed of, for example, a processor or a programmable device (such as an FPGA or a PLD), etc., and controls the charging or discharging of the storage battery Bc.

[0050] Also, during discharging or at the end of discharging of the storage battery Bc, the control unit Cntc obtains the state of charge SOCc of the storage battery Bc (the ratio of the remaining capacity of the storage battery Bc to the full charge capacity of the storage battery Bc), and sends the obtained state of charge SOCc to the control circuit 6. For example, the control unit Cntc refers to information indicating the correspondence between the open circuit voltage of the storage battery Bc and the state of charge SOCc, and sets the state of charge SOCc corresponding to the open circuit voltage of the storage battery Bc estimated by the voltage V1 as the state of charge SOCc of the storage battery Bc during discharging or after discharging. Or, the control unit Cntc sets the state of charge SOCc calculated by the following formula 2 as the state of charge SOCc of the storage battery Bc during discharging or after discharging.

[0051] State of charge SOCc = State of charge SOCc at the start of discharging + (Integrated value of the current I1 flowing through the storage battery Bc from the start of discharging to the present / Full charge capacity of the storage battery Bc) × 100 ··· Formula 2

[0052] <Regarding the AC / DC conversion circuit 4> The AC / DC conversion circuit 4 includes diodes D1 to D8, capacitors C1 and C2, switching elements SW1 to SW4, a transformer T1, an inductor L, a temperature detector St2, current detectors Si2 and Si3, and voltage detectors Sv2 and Sv3. The switching elements SW1 to SW4 are, for example, MOSFETs (Metal Oxide Semiconductor Field Effect Transistors).

[0053] A connection point between the anode terminal of the diode D1 and the cathode terminal of the diode D2 is connected to the R phase of the power system P, a connection point between the anode terminal of the diode D3 and the cathode terminal of the diode D4 is connected to the S phase of the power system P, and a connection point between the anode terminal of the diode D5 and the cathode terminal of the diode D6 is connected to the T phase of the power system P. The cathode terminals of the diodes D1, D3, and D5 are connected to the drain terminals of the switching elements SW1 and SW3 via one terminal of the capacitor C1. The anode terminals of the diodes D2, D4, and D6 are connected to the source terminals of the switching elements SW2 and SW4 via the other terminal of the capacitor C1. A connection point between the source terminal of the switching element SW1 and the drain terminal of the switching element SW2 is connected to one terminal of the primary coil L11 of the transformer T1, and a connection point between the source terminal of the switching element SW3 and the drain terminal of the switching element SW4 is connected to the other terminal of the primary coil L11. The anode terminal of diode D7 is connected to one terminal of the secondary coil L12 of transformer T1, and the anode terminal of diode D8 is connected to the other terminal of the secondary coil L12. The cathode terminals of diodes D7 and D8 are connected to one terminal of capacitor C2 via inductor L, and the other terminal of capacitor C2 is connected to the center tap of secondary coil L12. When charger 1 and power storage device 2 are connected to each other via a charging cable, one terminal of capacitor C2 and the positive terminal of battery Bv are connected to each other, and the other terminal of capacitor C2 and the negative terminal of battery Bv are connected to each other.

[0054] That is, the diodes D1 to D6 form a rectifier circuit and rectify the three-phase AC power supplied from the power system P. The capacitor C1 forms a smoothing circuit and smoothes the power rectified by the diodes D1 to D6. The switching elements SW1 to SW4, the transformer T1, the diodes D7 and D8, the inductor L, and the capacitor C2 form a forward type isolated DC-DC converter. The switching elements SW1 and SW4 and the switching elements SW2 and SW3 are alternately turned on and off, so that the power smoothed by the capacitor C1 is converted to AC and transmitted from the primary coil L11 to the secondary coil L12. The AC power transmitted to the secondary coil L12 is rectified by the diodes D7 and D8, smoothed by the capacitor C2, and output as DC power.

[0055] The temperature detection unit St2 is configured with, for example, a thermistor, detects the temperature of the components (diodes D1 to D6, switching elements SW1 to SW4, etc.) that configure the AC / DC conversion circuit 4, and sends the detected temperature to the control circuit 6.

[0056] The current detection unit Si2 is configured, for example, by a Hall element or a shunt resistor, detects the current I2 flowing in the R phase of the power system P, and sends the detected current I2 to the control circuit 6. The current detection unit Si2 may be configured to detect the current I2 flowing in the S phase or T phase of the power system P.

[0057] The voltage detection unit Sv2 is configured, for example, with a plurality of voltage dividing resistors connected in series with each other, detects the line voltage V2 between the R phase and the S phase of the power system P, and sends the detected line voltage V2 to the control circuit 6. Note that the voltage detection unit Sv2 may be configured to detect the line voltage V2 between the S phase and the T phase of the power system P, or the line voltage V2 between the R phase and the T phase of the power system P.

[0058] The current detection unit Si3 is configured with, for example, a Hall element or a shunt resistor, detects the current I3 output from the AC / DC conversion circuit 4, and sends the detected current I3 to the control circuit 6.

[0059] The voltage detection unit Sv3 is composed of, for example, a plurality of voltage dividing resistors connected in series with each other, detects the voltage V3 output from the AC / DC conversion circuit 4, and sends the detected voltage V3 to the control circuit 6.

[0060] <Regarding the DC / DC conversion circuit 5> The DC / DC conversion circuit 5 includes capacitors C3 and C4, switching elements SW5 to SW12, a transformer T2, a temperature detection unit St3, a current detection unit Si4, and a voltage detection unit Sv4. Note that the switching elements SW5 to SW12 are, for example, MOSFETs.

[0061] The drain terminals of the switching elements SW5 and SW7 are connected to the positive terminal of the storage battery Bc via one terminal of the capacitor C3, and the source terminals of the switching elements SW6 and SW8 are connected to the negative terminal of the storage battery Bc via the other terminal of the capacitor C3. The connection point between the source terminal of the switching element SW5 and the drain terminal of the switching element SW6 is connected to one terminal of the primary coil L21 of the transformer T2, and the connection point between the source terminal of the switching element SW7 and the drain terminal of the switching element SW8 is connected to the other terminal of the primary coil L21. The drain terminals of the switching elements SW9 and SW11 are connected to one terminal of the capacitor C4, and the source terminals of the switching elements SW10 and SW12 are connected to the other terminal of the capacitor C4. The connection point between the source terminal of the switching element SW9 and the drain terminal of the switching element SW10 is connected to one terminal of the secondary coil L22 of the transformer T2, and the connection point between the source terminal of the switching element SW11 and the drain terminal of the switching element SW12 is connected to the other terminal of the secondary coil L22. When the charger 1 and the power storage device 2 are connected to each other via a charging cable, one terminal of the capacitor C4 and the positive terminal of the battery Bv are connected to each other, and the other terminal of the capacitor C4 and the negative terminal of the battery Bv are connected to each other.

[0062] That is, the capacitors C3 and C4, the switching elements SW5 to SW12, and the transformer T2 constitute a bidirectional isolated DC-DC converter. The switching elements SW10 and SW11 and the switching elements SW9 and SW12 are alternately turned on and off, so that the DC power output from the AC / DC conversion circuit 4 is converted to AC and transmitted from the secondary coil L22 to the primary coil L21. The AC power transmitted to the primary coil L21 is rectified by diodes connected in parallel to the switching elements SW5 to SW8, respectively, smoothed by the capacitor C3, and output as DC power to the storage battery Bc. In addition, the switching elements SW5 and SW8 and the switching elements SW6 and SW7 are alternately turned on and off, so that the DC power output from the storage battery Bc is converted to AC and transmitted from the primary coil L21 to the secondary coil L22. The AC power transmitted to the secondary coil L22 is rectified by diodes connected in parallel to the switching elements SW9 to SW12, respectively, smoothed by the capacitor C4, and output as DC power.

[0063] The temperature detection unit St3 is configured with, for example, a thermistor, detects the temperature of the components (switching elements SW5 to SW12, etc.) that configure the DC / DC conversion circuit 5, and sends the detected temperature to the control circuit 6.

[0064] The current detection unit Si4 is configured with, for example, a Hall element or a shunt resistor, detects the current I4 output from the DC / DC conversion circuit 5, and sends the detected current I4 to the control circuit 6.

[0065] The voltage detection unit Sv4 is configured with, for example, a plurality of voltage dividing resistors connected in series with each other, detects the voltage V4 output from the DC / DC conversion circuit 5, and sends the detected voltage V4 to the control circuit 6.

[0066] <Regarding control circuit 6> The control circuit 6 is configured by, for example, a processor or a programmable device (such as an FPGA or a PLD), and controls the operations of the AC / DC conversion circuit 4 and the DC / DC conversion circuit 5.

[0067] When the charger 1 and the storage device 2 are not connected to each other, if the charging rate SOCc of the storage battery Bc falls below a threshold, the control circuit 6 performs constant-current constant-voltage charging control on the storage battery Bc. The constant-current constant-voltage charging control performed on the storage battery Bc is similar to the constant-current constant-voltage charging control performed on the battery Bv, and therefore a description thereof will be omitted.

[0068] Furthermore, when the charger 1 and the power storage device 3 are connected to each other, the control circuit 6 controls charging of the storage battery Bc upon input of an instruction to start charging the storage battery Bc by a user or the like. Note that the storage battery Bc and the charger 1 may be constantly connected, and in that case, the charger 1 may start charging the storage battery Bc by transmitting a connection simulation signal.

[0069] (Regarding the operation of the control circuit 6 during charging control of the battery Bv (part 1)) Assume that there is no need to limit the output (power, voltage, or current) of the storage battery Bc, the AC / DC conversion circuit 4, and the DC / DC conversion circuit 5 during charging control of the battery Bv. In other words, assume that there is a low possibility that the storage battery Bc, the components constituting the AC / DC conversion circuit 4, and the components constituting the DC / DC conversion circuit 5 will deteriorate or fail due to their own heat generation, and there is no need to reduce the maximum output of the storage battery Bc, the AC / DC conversion circuit 4, and the DC / DC conversion circuit 5. Note that the sum of the maximum output of the AC / DC conversion circuit 4 and the maximum output of the DC / DC conversion circuit 5 is equal to or greater than the required output Pt from the battery Bv (power, voltage, or current (command current) required from the battery Bv). For example, when the required output Pt is the power required from the battery Bv, the required output Pt is the multiplication value of the command current transmitted from the control unit Cntv and a voltage higher than the voltage V3 detected by the voltage detection unit Sv3 by a predetermined value.

[0070] In this case, the control circuit 6 controls the on / off of the switching elements SW1 to SW4 so that the AC / DC conversion circuit 4 outputs a primary output (for example, any power equal to or less than the maximum output power of the AC / DC conversion circuit 4, any voltage equal to or less than the maximum output voltage of the AC / DC conversion circuit 4, or any current equal to or less than the maximum output current of the AC / DC conversion circuit 4) of the required output Pt, and also controls the on / off of the switching elements SW5 to SW12 so that the DC / DC conversion circuit 5 outputs a secondary output obtained by subtracting the primary output from the required output Pt. In other words, when the control circuit 6 determines that it is not necessary to limit the outputs of the storage battery Bc, the AC / DC conversion circuit 4, and the DC / DC conversion circuit 5 during charging control of the battery Bv, it performs “normal charging control” in which a part of the required output Pt is supplied from the AC / DC conversion circuit 4 to the battery Bv and the remainder of the required output Pt is supplied from the DC / DC conversion circuit 5 to the battery Bv.

[0071] (Regarding the operation of the control circuit 6 during charging control of the battery Bv (part 2)) Assume that, during charging control of battery Bv, there is no need to limit the output of AC / DC conversion circuit 4, and there is a need to limit the output of storage battery Bc or DC / DC conversion circuit 5, and that it is possible to compensate for at least a portion of the limited output of DC / DC conversion circuit 5 by increasing the output of AC / DC conversion circuit 4.

[0072] In this case, the control circuit 6 controls the on / off of the switching elements SW1 to SW4 so that the AC / DC conversion circuit 4 outputs a supplementary main output (a main output increased by a predetermined output p1 compared to during normal charging control) of the required output Pt, and also controls the on / off of the switching elements SW5 to SW8 so that the DC / DC conversion circuit 5 outputs a limited secondary output (an arbitrary secondary output equal to or lower than the maximum output of the DC / DC conversion circuit 5 reduced by a predetermined output p2 compared to during normal charging control). That is, when the control circuit 6 determines that it is not necessary to limit the output of the AC / DC conversion circuit 4 during charging control of the battery Bv, and determines that it is necessary to limit the output of the storage battery Bc or the DC / DC conversion circuit 5, and determines that at least a part of the limited portion of the output of the DC / DC conversion circuit 5 can be compensated for by increasing the output of the AC / DC conversion circuit 4, it performs “output limited charging control of the DC / DC conversion circuit 5”. This makes it possible to suppress the occurrence of deterioration or failure of the components constituting the DC / DC conversion circuit 5, while also preventing the output of the charger 1 from falling short of the required output Pt.

[0073] (Operation of the control circuit 6 during charging control of the battery Bv (part 3)) Assume that, during charging control of battery Bv, it is necessary to limit the output of AC / DC conversion circuit 4, but there is no need to limit the output of storage battery Bc or DC / DC conversion circuit 5, and it is possible to compensate for at least a portion of the limited output of AC / DC conversion circuit 4 by increasing the output of DC / DC conversion circuit 5.

[0074] In this case, the control circuit 6 controls the on / off of the switching elements SW1 to SW4 so that the AC / DC conversion circuit 4 outputs a limited primary output (an arbitrary primary output equal to or lower than the maximum output of the AC / DC conversion circuit 4 lowered by a predetermined output p3 compared to during normal charging control) of the required output Pt, and also controls the on / off of the switching elements SW5 to SW8 so that the DC / DC conversion circuit 5 outputs a supplementary secondary output (a secondary output increased by a predetermined output p4 compared to during normal charging control). That is, when the control circuit 6 determines that it is necessary to limit the output of the AC / DC conversion circuit 4 during charging control of the battery Bv, and determines that it is not necessary to limit the output of the storage battery Bc or the DC / DC conversion circuit 5, and determines that at least a part of the limited portion of the output of the AC / DC conversion circuit 4 can be compensated for by increasing the output of the DC / DC conversion circuit 5, it performs “output limited charging control of the AC / DC conversion circuit 4” to cause the DC / DC conversion circuit 5 to output a supplementary secondary output and cause the AC / DC conversion circuit 4 to output a limited main output. This makes it possible to suppress the occurrence of deterioration or failure of the components constituting the AC / DC conversion circuit 4, while also preventing the output of the charger 1 from falling short of the required output Pt.

[0075] (Regarding the operation of the control circuit 6 during charging control of the battery Bv (part 4)) A case is assumed in which it is necessary to limit the output of the AC / DC conversion circuit 4 and also to limit the output of the storage battery Bc or the DC / DC conversion circuit 5 during charging control of the battery Bv.

[0076] In this case, the control circuit 6 controls the on / off of the switching elements SW1 to SW4 so that the limited main output of the required output Pt is output from the AC / DC conversion circuit 4, and controls the on / off of the switching elements SW5 to SW8 so that the limited secondary output is output from the DC / DC conversion circuit 5. That is, when the control circuit 6 determines that it is not necessary to limit the output of the AC / DC conversion circuit 4 during charging control of the battery Bv, and determines that it is not necessary to limit the output of the storage battery Bc or the DC / DC conversion circuit 5, it performs "output limited charging control of the AC / DC conversion circuit 4 and the DC / DC conversion circuit 5" to output the limited main output from the AC / DC conversion circuit 4 and the limited secondary output from the DC / DC conversion circuit 5. This makes it possible to suppress the occurrence of deterioration and failure of the components constituting the AC / DC conversion circuit 4 and the DC / DC conversion circuit 5.

[0077] <Maximum output of the storage battery Bc, the AC / DC conversion circuit 4, and the DC / DC conversion circuit 5> FIG. 4(a) is a diagram showing an example of the relationship between the temperature of the storage battery Bc and the maximum output of the storage battery Bc. The horizontal axis of the two-dimensional coordinate system shown in FIG. 4(a) indicates the temperature, and the vertical axis indicates the maximum output of the storage battery Bc (the maximum power, maximum voltage, or maximum current output from the storage battery Bc). The solid line shown in FIG. 4(a) indicates an example of information Db1 showing the relationship between the temperature of the storage battery Bc and the maximum output of the storage battery Bc when the storage battery Bc has a first charging rate SOCc. The dashed line shown in FIG. 4(a) indicates an example of information Db2 showing the relationship between the temperature of the storage battery Bc and the maximum output of the storage battery Bc when the storage battery Bc has a second charging rate SOCc. The dashed line shown in FIG. 4(a) indicates an example of information Db3 showing the relationship between the temperature of the storage battery Bc and the maximum output of the storage battery Bc when the storage battery Bc has a third charging rate SOCc. The first charging rate<the second charging rate<the third charging rate. In addition, the following relationship is established: first rated upper limit temperature TH1'>first high temperature threshold TH1>0>first low temperature threshold TL1>first rated lower limit temperature TL1'. In addition, the following relationship is established: maximum output Pb1<maximum output Pb2<maximum output Pb3.

[0078] Moreover, the information Db1 shown in FIG. 4(a) may be stored in the control circuit 6 or in the control unit Cntc. When the information Db1 shown in FIG. 4(a) is stored in the control unit Cntc, the control unit Cntc refers to the information Db1 shown in FIG. 4(a) to determine the maximum output of the storage battery Bc, and transmits the determined maximum output to the control circuit 6. Moreover, the information Db1 shown in FIG. 4(a) may be changed according to the degree of deterioration of the storage battery Bc. For example, information Db1' indicating the relationship between the temperature of the storage battery Bc after deterioration and the maximum output of the storage battery Bc after deterioration may be stored in advance in the control circuit 6 or the control unit Cntc, and when the storage battery Bc deteriorates, the information Db1 may be switched to the information Db1'.

[0079] 4(b) is a diagram showing an example of the relationship between the temperature of the components constituting the DC / DC conversion circuit 5 and the maximum output of the DC / DC conversion circuit 5. The horizontal axis of the two-dimensional coordinate system shown in FIG. 4(b) indicates temperature, and the vertical axis indicates the maximum output of the DC / DC conversion circuit 5 (maximum power, maximum voltage, or maximum current output from the DC / DC conversion circuit 5). The solid line shown in FIG. 4(b) indicates an example of information Ddc indicating the relationship between the temperature of the components constituting the DC / DC conversion circuit 5 and the maximum output of the DC / DC conversion circuit 5. The second rated upper limit temperature TH2'>second high temperature threshold TH2>0>second low temperature threshold TL2>second rated lower limit temperature TL2'.

[0080] The control circuit 6 refers to the information Db1 to Db3 shown in Figure 4 (a) and determines that there is no need to limit the output of the storage battery Bc when the positive temperature detected by the temperature detection unit St1 is greater than zero and less than the first high temperature threshold TH1, or when the negative temperature detected by the temperature detection unit St1 is less than zero and greater than the first low temperature threshold TL1.

[0081] The control circuit 6 refers to the information Db1 to Db3 shown in Figure 4 (a) and determines that it is necessary to limit the output of the storage battery Bc when the positive temperature detected by the temperature detection unit St1 is within the range from the first high temperature threshold TH1 to the first rated upper limit temperature TH1', or when the negative temperature detected by the temperature detection unit St1 is within the range from the first low temperature threshold TL1 to the first rated lower limit temperature TL1'.

[0082] During charging control of the battery Bv, when the positive temperature detected by the temperature detection unit St1 becomes higher than the first rated upper limit temperature TH1', or when the negative temperature detected by the temperature detection unit St1 becomes lower than the first rated lower limit temperature TL1', the control circuit 6 stops the AC / DC conversion circuit 4 and the DC / DC conversion circuit 5 and terminates the charging control of the battery Bv.

[0083] In addition, the control circuit 6 refers to the information Ddc shown in Figure 4 (b) and determines that there is no need to limit the output of the DC / DC conversion circuit 5 when the positive temperature detected by the temperature detection unit St3 is greater than zero and less than the second high temperature threshold TH2, or when the negative temperature detected by the temperature detection unit St3 is less than zero and greater than the second low temperature threshold TL2.

[0084] The control circuit 6 refers to the information Ddc shown in Figure 4(b) and determines that it is necessary to limit the output of the DC / DC conversion circuit 5 when the positive temperature detected by the temperature detection unit St3 is within the range from the second high temperature threshold TH2 to the second rated upper limit temperature TH2', or when the negative temperature detected by the temperature detection unit St3 is within the range from the second low temperature threshold TL2 to the second rated lower limit temperature TL2'.

[0085] During charging control of the battery Bv, when the positive temperature detected by the temperature detection unit St3 becomes higher than the second rated upper limit temperature TH2', or when the negative temperature detected by the temperature detection unit St3 becomes lower than the second rated lower limit temperature TL2', the control circuit 6 stops the AC / DC conversion circuit 4 and the DC / DC conversion circuit 5 and terminates the charging control of the battery Bv.

[0086] (Output of storage battery Bc and DC / DC conversion circuit 5: No limit) For example, when the control circuit 6 determines that it is not necessary to limit the output of the storage battery Bc and the DC / DC conversion circuit 5 and the charging rate SOCc of the storage battery Bc is a first charging rate, it sets a maximum output Pb1 as the maximum output of the storage battery Bc and the DC / DC conversion circuit 5. When the control circuit 6 determines that it is not necessary to limit the output of the storage battery Bc and the DC / DC conversion circuit 5 and the charging rate SOCc of the storage battery Bc is a second charging rate, it sets a maximum output Pb2 as the maximum output of the storage battery Bc and the DC / DC conversion circuit 5. When the control circuit 6 determines that it is not necessary to limit the output power of the storage battery Bc and the DC / DC conversion circuit 5 and the charging rate SOCc of the storage battery Bc is a third charging rate, it sets a maximum output Pb3 as the maximum output of the storage battery Bc and the DC / DC conversion circuit 5.

[0087] That is, when there is no need to limit the output of the storage battery Bc and the DC / DC conversion circuit 5, the maximum output of the storage battery Bc and the DC / DC conversion circuit 5 increases as the charging rate SOCc of the storage battery Bc increases.

[0088] (Output of storage battery Bc: limited, output of DC / DC conversion circuit 5: no limit) For example, when the control circuit 6 determines that it is necessary to limit the output of the storage battery Bc because the positive temperature detected by the temperature detection unit St1 is within the range from the first high temperature threshold TH1 to the first rated upper limit temperature TH1', and when it determines that it is not necessary to limit the output of the DC / DC conversion circuit 5, and when the charging rate SOCc of the storage battery Bc is the first charging rate, the control circuit 6 reduces the maximum output of the DC / DC conversion circuit 5 within the range from zero to the maximum output Pb1 as the positive temperature detected by the temperature detection unit St1 becomes higher.

[0089] In addition, when the control circuit 6 determines that it is necessary to limit the output of the storage battery Bc because the negative temperature detected by the temperature detection unit St1 is within the range from the first low temperature threshold TL1 to the first rated lower limit temperature TL1', and when it determines that it is not necessary to limit the output of the DC / DC conversion circuit 5, and when the charging rate SOCc of the storage battery Bc is the first charging rate, the control circuit 6 reduces the maximum output of the DC / DC conversion circuit 5 in the range from zero to the maximum output Pb1 as the negative temperature detected by the temperature detection unit St1 becomes lower.

[0090] In addition, when the control circuit 6 determines that it is necessary to limit the output power of the storage battery Bc because the positive temperature detected by the temperature detection unit St1 is within the range from the first high temperature threshold TH1 to the first rated upper limit temperature TH1', and when it determines that it is not necessary to limit the output of the DC / DC conversion circuit 5, and when the charging rate SOCc of the storage battery Bc is the second charging rate, the control circuit 6 reduces the maximum output of the DC / DC conversion circuit 5 in the range from zero to the maximum output Pb2 as the positive temperature detected by the temperature detection unit St1 becomes higher.

[0091] In addition, when the control circuit 6 determines that it is necessary to limit the output of the storage battery Bc because the negative temperature detected by the temperature detection unit St1 is within the range from the first low temperature threshold TL1 to the first rated lower limit temperature TL1', and when it determines that it is not necessary to limit the output of the DC / DC conversion circuit 5, and when the charging rate SOCc of the storage battery Bc is the second charging rate, the control circuit 6 reduces the maximum output of the DC / DC conversion circuit 5 in the range from zero to the maximum output Pb2 as the negative temperature detected by the temperature detection unit St1 becomes lower.

[0092] In addition, when the control circuit 6 determines that it is necessary to limit the output of the storage battery Bc because the positive temperature detected by the temperature detection unit St1 is within the range from the first high temperature threshold TH1 to the first rated upper limit temperature TH1', and when it determines that it is not necessary to limit the output of the DC / DC conversion circuit 5, and when the charging rate SOCc of the storage battery Bc is the third charging rate, the control circuit 6 reduces the maximum output of the DC / DC conversion circuit 5 in the range from zero to the maximum output Pb3 as the positive temperature detected by the temperature detection unit St1 becomes higher.

[0093] In addition, when the control circuit 6 determines that it is necessary to limit the output of the storage battery Bc because the negative temperature detected by the temperature detection unit St1 is within the range from the first low temperature threshold TL1 to the first rated lower limit temperature TL1', and when it determines that it is not necessary to limit the output of the DC / DC conversion circuit 5, and when the charging rate SOCc of the storage battery Bc is the third charging rate, the control circuit 6 reduces the maximum output of the DC / DC conversion circuit 5 in the range from zero to the maximum output Pb3 as the negative temperature detected by the temperature detection unit St1 becomes lower.

[0094] In this way, the maximum output of the DC / DC conversion circuit 5 can be reduced in accordance with an increase in the positive temperature or a decrease in the negative temperature of the storage battery Bc, thereby suppressing heat generation in the storage battery Bc and preventing deterioration or failure of the storage battery Bc due to heat generation in the storage battery Bc.

[0095] (Output of storage battery Bc: no limit, output of DC / DC conversion circuit 5: limited) For example, when the control circuit 6 determines that there is no need to limit the output of the storage battery Bc, and also determines that the output of the DC / DC conversion circuit 5 needs to be limited because the positive temperature detected by the temperature detection unit St3 is within the range from the second high temperature threshold TH2 to the second rated upper limit temperature TH2', the control circuit 6 reduces the maximum output of the DC / DC conversion circuit 5 in the range from zero to the maximum output Pdc as the positive temperature detected by the temperature detection unit St3 becomes higher.

[0096] In addition, when the control circuit 6 determines that there is no need to limit the output of the storage battery Bc and that the output of the DC / DC conversion circuit 5 needs to be limited because the negative temperature detected by the temperature detection unit St3 is within the range from the second low temperature threshold TL2 to the second rated lower limit temperature TL2', the control circuit 6 reduces the maximum output of the DC / DC conversion circuit 5 in the range from zero to the maximum output Pdc as the negative temperature detected by the temperature detection unit St3 becomes lower.

[0097] In this way, the maximum output of the DC / DC conversion circuit 5 can be reduced in accordance with an increase in positive temperature or a decrease in negative temperature of the components that constitute the DC / DC conversion circuit 5, thereby making it possible to suppress heat generation in the components that constitute the DC / DC conversion circuit 5 and to suppress deterioration or failure of the components that constitute the DC / DC conversion circuit 5 due to heat generation from the components that constitute the DC / DC conversion circuit 5.

[0098] Fig. 4(c) is a diagram showing the relationship between the temperatures of the components constituting the AC / DC conversion circuit 4 and the maximum output of the AC / DC conversion circuit 4. The horizontal axis of the two-dimensional coordinate system shown in Fig. 4(c) indicates temperature, and the vertical axis indicates the maximum output of the AC / DC conversion circuit 4. The solid line shown in Fig. 4(c) indicates an example of information Dac indicating the relationship between the temperatures of the components constituting the AC / DC conversion circuit 4 and the maximum output of the AC / DC conversion circuit 4. The following relationship is assumed: third rated upper limit temperature TH3'>third high temperature threshold TH3>0>third low temperature threshold TL3>third rated lower limit temperature TL3'.

[0099] The control circuit 6 refers to the information Dac shown in Figure 4 (c) and determines that there is no need to limit the output of the AC / DC conversion circuit 4 when the positive temperature detected by the temperature detection unit St2 is lower than the third high temperature threshold TH3, or when the negative temperature detected by the temperature detection unit St2 is higher than the third low temperature threshold TL3.

[0100] The control circuit 6 refers to the information Dac shown in Figure 4 (c) and determines that it is necessary to limit the output of the DC / DC conversion circuit 5 when the positive temperature detected by the temperature detection unit St2 is within the range from the third high temperature threshold TH3 to the third rated upper limit temperature TH3', or when the negative temperature detected by the temperature detection unit St2 is within the range from the third low temperature threshold TL3 to the third rated lower limit temperature TL3'.

[0101] During charging control of the battery Bv, when the positive temperature detected by the temperature detection unit St2 becomes higher than the third rated upper limit temperature TH3', or when the negative temperature detected by the temperature detection unit St2 becomes lower than the third rated lower limit temperature TL3', the control circuit 6 stops the AC / DC conversion circuit 4 and the DC / DC conversion circuit 5 and terminates the charging control of the battery Bv.

[0102] (AC / DC conversion circuit 4 output: No limit) For example, when the control circuit 6 determines that it is not necessary to limit the output power of the AC / DC conversion circuit 4, it sets the maximum output Pac as the maximum output of the AC / DC conversion circuit 4.

[0103] (AC / DC conversion circuit 4 output: Limited) For example, if the control circuit 6 determines that it is necessary to limit the output of the AC / DC conversion circuit 4 because the positive temperature detected by the temperature detection unit St2 is within the range from the third high temperature threshold TH3 to the third rated upper limit temperature TH3', the control circuit 6 reduces the maximum output of the AC / DC conversion circuit 4 within the range from zero to the maximum output Pac as the positive temperature detected by the temperature detection unit St2 becomes higher.

[0104] In addition, when the control circuit 6 determines that it is necessary to limit the output of the AC / DC conversion circuit 4 because the negative temperature detected by the temperature detection unit St2 is within the range from the third low temperature threshold TL3 to the third rated lower limit temperature TL3', the control circuit 6 reduces the maximum output of the AC / DC conversion circuit 4 in the range from zero to the maximum output Pac as the negative temperature detected by the temperature detection unit St2 becomes lower.

[0105] In this way, the maximum output of the AC / DC conversion circuit 4 can be reduced in accordance with an increase in positive temperature or a decrease in negative temperature of the components that make up the AC / DC conversion circuit 4, thereby making it possible to suppress heat generation in the components that make up the AC / DC conversion circuit 4 and to suppress deterioration or failure of the components that make up the AC / DC conversion circuit 4 due to heat generation from the components that make up the AC / DC conversion circuit 4.

[0106] However, if restrictions are placed on the output of at least one of the storage battery Bc, the AC / DC conversion circuit 4, and the DC / DC conversion circuit 5 during charging control of the battery Bv, the output of the charger 1 may not meet the required output Pt from the battery Bv, and the charging time of the battery Bv may increase.

[0107] Therefore, in the charger 1 of the embodiment, when a limit is placed on the output of at least one of the storage battery Bc, the AC / DC conversion circuit 4, and the DC / DC conversion circuit 5, the limited output is compensated for by increasing the output that is not limited among the outputs of the storage battery Bc, the AC / DC conversion circuit 4, and the DC / DC conversion circuit 5. As a result, even if a limit is placed on the output of at least one of the storage battery Bc, the AC / DC conversion circuit 4, and the DC / DC conversion circuit 5 during charging control of the battery Bv, the output from the charger 1 to the battery Bv can be made close to the required output Pt from the battery Bv, and an increase in the charging time of the battery Bv can be suppressed.

[0108] In addition, batteries installed in industrial vehicles are generally subject to frequent charging and discharging throughout the day, and the temperature of the components that make up the charger used to charge the battery tends to become relatively high, which can easily lead to deterioration or failure of the components that make up the charger.

[0109] Therefore, the charger 1 of the embodiment can suppress an increase in the charging time of the battery Bv while suppressing deterioration and failure of the storage battery Bc, the components constituting the AC / DC conversion circuit 4, and the components constituting the DC / DC conversion circuit 5, and is therefore suitable as a charger for charging batteries installed in industrial vehicles.

[0110] FIG. 5 is a flowchart showing an example of the operation of the control circuit 6 during charging control of the battery Bv.

[0111] When the control circuit 6 determines that there is no need to limit the output of the AC / DC conversion circuit 4 (step STP1: No), and also determines that there is no need to limit the output of the storage battery Bc or the DC / DC conversion circuit 5 ("step STP2: No, step STP3: No"), it performs "normal charging control" (step STP4).

[0112] Alternatively, when the control circuit 6 determines that there is no need to limit the output of the AC / DC conversion circuit 4 (step STP1: No) and determines that it is necessary to limit the output of the storage battery Bc or the DC / DC conversion circuit 5 ("Step STP2: Yes", or "Step STP2: No, Step STP3: Yes"), it performs "output limiting charging control of the DC / DC conversion circuit 5" (step STP5).

[0113] Alternatively, when the control circuit 6 determines that it is necessary to limit the output of the AC / DC conversion circuit 4 (step STP1: Yes) and determines that it is not necessary to limit the output of the storage battery Bc and the DC / DC conversion circuit 5 ("step STP6: No, step STP7: No"), it performs "output limiting charging control of the AC / DC conversion circuit 4" (step STP8).

[0114] Alternatively, when the control circuit 6 determines that it is necessary to limit the output of the AC / DC conversion circuit 4 (step STP1: Yes) and also determines that it is necessary to limit the output of the storage battery Bc or the DC / DC conversion circuit 5 ("step STP6: Yes", or "step STP6: No, step STP7: Yes"), it performs "output limiting charging control of the AC / DC conversion circuit 4 and the DC / DC conversion circuit 5" (step STP9).

[0115] FIG. 6 is a flowchart showing an example of the operation of the control circuit 6 during output limiting charging control of the DC / DC conversion circuit 5.

[0116] First, when the current output of the charger 1 is smaller than the required output Pt (step STP51: Yes) and the supplementary main output outputted from the AC / DC conversion circuit 4 is smaller than the maximum output of the AC / DC conversion circuit 4 (step STP52: Yes), the control circuit 6 controls the operation of the DC / DC conversion circuit 5 so that the DC / DC conversion circuit 5 outputs a limited secondary output, and controls the operation of the AC / DC conversion circuit 4 so that the AC / DC conversion circuit 4 outputs an increased supplementary main output (step STP53). That is, when the sum of the current supplementary main output and the current limited secondary output does not reach the required output Pt and the current supplementary main output does not reach the maximum output of the AC / DC conversion circuit 4, the control circuit 6 determines that the current supplementary main output can be increased to the maximum output of the AC / DC conversion circuit 4, and further increases the current supplementary main output by a predetermined output p1' with the maximum output of the AC / DC conversion circuit 4 as the upper limit. As a result, when the current output of the charger 1 becomes equal to or greater than the required output Pt, the entire limited portion of the secondary output can be compensated for.

[0117] Alternatively, when the current output of the charger 1 is smaller than the required output Pt (step STP51: Yes) and the supplementary main output output from the AC / DC conversion circuit 4 is equal to or greater than the maximum output of the AC / DC conversion circuit 4 (step STP52: No), the control circuit 6 controls the operation of the DC / DC conversion circuit 5 so that the DC / DC conversion circuit 5 outputs a limited secondary output, and controls the operation of the AC / DC conversion circuit 4 so that the AC / DC conversion circuit 4 continues to output the maximum output as the supplementary main output (step STP54). That is, when the sum of the current supplementary main output and the current limited secondary output does not reach the required output Pt and the current supplementary main output has reached the maximum output of the AC / DC conversion circuit 4, the control circuit 6 determines that the current supplementary main output cannot be increased any more, and causes the AC / DC conversion circuit 4 to continue to output the maximum output as the supplementary main output.

[0118] Alternatively, when the current output of the charger 1 is equal to or greater than the required output Pt (step STP51: No), the control circuit 6 controls the operation of the DC / DC conversion circuit 5 so that a limited secondary output is output from the DC / DC conversion circuit 5, and controls the operation of the AC / DC conversion circuit 4 so that a supplementary main output is output from the AC / DC conversion circuit 4 (step STP55). In other words, when the sum of the current supplementary main output and the current limited secondary output has reached the required output Pt, the control circuit 6 determines that it is not necessary to further increase the current supplementary main output to supplement the limited portion of the secondary output, and continues to output the current supplementary main output and the current limited secondary output.

[0119] FIG. 7 is a flowchart showing an example of the operation of the control circuit 6 during output limiting charging control of the AC / DC conversion circuit 4.

[0120] First, when the current output of the charger 1 is smaller than the required output Pt (step STP61: Yes) and the compensation secondary output output from the DC / DC conversion circuit 5 is smaller than the maximum output of the DC / DC conversion circuit 5 (step STP62: Yes), the control circuit 6 controls the operation of the AC / DC conversion circuit 4 so that the limited main output is output from the AC / DC conversion circuit 4, and controls the operation of the DC / DC conversion circuit 5 so that the increased compensation secondary output is output from the DC / DC conversion circuit 5 (step STP63). That is, when the sum of the current limited main output and the current compensation secondary output does not reach the required output Pt and the current compensation secondary output does not reach the maximum output of the DC / DC conversion circuit 5, the control circuit 6 determines that the current compensation secondary output can be increased to the maximum output of the DC / DC conversion circuit 5, and further increases the current compensation secondary output by a predetermined output p4' with the maximum output of the DC / DC conversion circuit 5 as the upper limit. As a result, when the current output of the charger 1 becomes equal to or greater than the required output Pt, the entire limited portion of the main output can be compensated for.

[0121] Alternatively, when the current output of the charger 1 is smaller than the required output Pt (step STP61: Yes) and the compensation secondary output output from the DC / DC conversion circuit 5 is equal to or greater than the maximum output of the DC / DC conversion circuit 5 (step STP62: No), the control circuit 6 controls the operation of the AC / DC conversion circuit 4 so that the limited main output is output from the AC / DC conversion circuit 4, and controls the operation of the DC / DC conversion circuit 5 so that the maximum output is continuously output from the DC / DC conversion circuit 5 as the compensation secondary output (step STP64). That is, when the sum of the current limited main output and the current compensation secondary output does not reach the required output Pt and the current compensation secondary output has reached the maximum output of the DC / DC conversion circuit 5, the control circuit 6 determines that the current compensation secondary output cannot be increased any further, and causes the DC / DC conversion circuit 5 to continue to output the maximum output as the compensation secondary output.

[0122] Alternatively, when the current output of the charger 1 is equal to or greater than the required output Pt (step STP61: No), the control circuit 6 controls the operation of the AC / DC conversion circuit 4 so that the AC / DC conversion circuit 4 outputs a limited main output, and controls the operation of the DC / DC conversion circuit 5 so that the DC / DC conversion circuit 5 outputs a supplementary secondary output (step STP65). In other words, when the sum of the current limited main output and the current supplementary secondary output has reached the required output Pt, the control circuit 6 determines that it is not necessary to further increase the current supplementary secondary output to supplement the limited portion of the main output, and continues to output the current limited main output and the current supplementary secondary output.

[0123] In this way, the charger 1 of the embodiment is configured to control the operation of the DC / DC conversion circuit 5 so that a limited secondary output is output from the DC / DC conversion circuit 5 and to control the operation of the AC / DC conversion circuit 4 so that a supplementary main output is output from the AC / DC conversion circuit 5 when it is determined that there is no need to limit the output of the AC / DC conversion circuit 4 and that there is no need to limit the output of the storage battery Bc or the DC / DC conversion circuit 5. Also, the charger 1 of the embodiment is configured to control the operation of the AC / DC conversion circuit 4 so that a limited main output is output from the AC / DC conversion circuit 4 and to control the operation of the DC / DC conversion circuit 5 so that a supplementary secondary output is output from the DC / DC conversion circuit 5 when it is determined that there is no need to limit the output of the AC / DC conversion circuit 4 and that there is no need to limit the outputs of the storage battery Bc and the DC / DC conversion circuit 5.

[0124] As a result, when at least a part of the limited amount of the limited secondary output of the storage battery Bc or the DC / DC conversion circuit 5 can be compensated for by an increase in the compensation main output of the AC / DC conversion circuit 4, the output of the charger 1 can be made closer to the required output Pt from the battery Bv while limiting the output of the storage battery Bc or the DC / DC conversion circuit 5. Also, when at least a part of the limited amount of the limited primary output of the AC / DC conversion circuit 4 can be compensated for by an increase in the compensation secondary output of the DC / DC conversion circuit 5, the output of the charger 1 can be made closer to the required output Pt from the battery while limiting the output of the AC / DC conversion circuit 4. Therefore, it is possible to suppress an increase in the charging time of the battery Bv while suppressing the occurrence of deterioration and failure of the storage battery Bc, the AC / DC conversion circuit 4, and the DC / DC conversion circuit 5.

[0125] 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.

[0126] <Variation 1> In the above embodiment, when calculating the maximum output of the storage battery Bc, the relationship between the temperature of the storage battery Bc and the maximum output of the storage battery Bc is calculated by referring to information indicating the relationship between the temperature of the storage battery Bc and the maximum output of the storage battery Bc for each charging rate SOCc of the storage battery Bc. However, it is also possible to calculate two maximum outputs by referring to information indicating the relationship between the temperature of the storage battery Bc and the maximum output of the storage battery Bc, and information indicating the relationship between the charging rate SOCc of the storage battery Bc and the maximum output of the storage battery Bc, and to adopt the smaller of the two maximum outputs thus calculated.

[0127] <Variation 2> In the above embodiment, the temperature is used as a parameter for determining the maximum output of the storage battery Bc, the AC / DC conversion circuit 4, and the DC / DC conversion circuit 5, but the parameter is not limited to temperature as long as it is a parameter that changes in conjunction with changes in the maximum output of the storage battery Bc, the AC / DC conversion circuit 4, and the DC / DC conversion circuit 5. For example, the degree of deterioration (State Of Health) of the storage battery Bc may be used as a parameter that changes in conjunction with changes in the maximum output of the storage battery Bc, the AC / DC conversion circuit 4, and the DC / DC conversion circuit 5. [Explanation of symbols]

[0128] 1 charger 2, 3 Energy storage device 4 AC / DC conversion circuit 5 DC / DC conversion circuit 6 Control Circuit P grid power supply Vehicle Bv Battery Bc storage battery Cntv, Cntc control unit D1~D8 Diodes C1~C4 capacitors SW1~SW12 Switching elements T1, T2 transformers L Inductor St1~St3 Temperature detection section Si1~Si4 Current detection section Sv1~Sv4 Voltage detection section

Claims

1. A charger for supplying power to a battery, comprising: A storage battery, an AC / DC conversion circuit that converts AC power supplied from a power source into DC power and outputs the DC power to the battery or the storage battery; a DC / DC conversion circuit that converts the DC power supplied from the storage battery into a predetermined DC power and outputs the DC power to the battery; a control circuit for controlling operations of the AC / DC conversion circuit and the DC / DC conversion circuit; Equipped with The control circuit includes: when it is determined that there is no need to limit the outputs of the storage battery, the AC / DC conversion circuit, and the DC / DC conversion circuit, control the operation of the AC / DC conversion circuit so that a primary output is output from the AC / DC conversion circuit, and control the operation of the DC / DC conversion circuit so that a secondary output obtained by subtracting the primary output from a required output from the battery is output from the DC / DC conversion circuit; when it is determined that there is no need to limit the output of the AC / DC conversion circuit and when it is determined that there is a need to limit the output of the storage battery or the DC / DC conversion circuit, controlling the operation of the DC / DC conversion circuit so that a limited secondary output is output from the DC / DC conversion circuit, and controlling the operation of the AC / DC conversion circuit so that a supplementary main output obtained by increasing the main output is output from the AC / DC conversion circuit; When it is determined that it is necessary to limit the output of the AC / DC conversion circuit, and when it is determined that it is not necessary to limit the outputs of the storage battery and the DC / DC conversion circuit, the operation of the AC / DC conversion circuit is controlled so that a limited main output is output from the AC / DC conversion circuit, and the operation of the DC / DC conversion circuit is controlled so that a supplementary secondary output obtained by increasing the secondary output is output from the DC / DC conversion circuit. charger.

2. 2. The charger according to claim 1, When it is determined that there is no need to limit the output of the AC / DC conversion circuit, when it is determined that there is a need to limit the output of the storage battery or the DC / DC conversion circuit, when the current output of the charger is smaller than the output required from the battery, and when the supplementary main output is smaller than the maximum output of the AC / DC conversion circuit, the control circuit controls the operation of the AC / DC conversion circuit so that the increased supplementary main output is output from the AC / DC conversion circuit. charger.

3. 2. The charger according to claim 1, When it is determined that it is necessary to limit the output of the AC / DC conversion circuit, when it is determined that it is not necessary to limit the output of the storage battery or the DC / DC conversion circuit, when the current output of the charger is smaller than the output required from the battery, and when the compensation secondary output is smaller than the current maximum output of the DC / DC conversion circuit, the control circuit controls the operation of the DC / DC conversion circuit so that the increased compensation secondary output is output from the DC / DC conversion circuit. charger.

4. 2. The charger according to claim 1, When it is determined that there is no need to limit the output of the AC / DC conversion circuit, when it is determined that there is a need to limit the output of the storage battery or the DC / DC conversion circuit, when the current output of the charger is smaller than the output required from the battery, and when the supplementary main output is equal to or greater than the maximum output of the AC / DC conversion circuit, the control circuit controls the operation of the AC / DC conversion circuit so that the supplementary main output is continuously output from the AC / DC conversion circuit. charger.

5. 2. The charger according to claim 1, When it is determined that it is necessary to limit the output of the AC / DC conversion circuit, when it is determined that it is not necessary to limit the outputs of the storage battery and the DC / DC conversion circuit, when the current output of the charger is smaller than the output required from the battery, and when the supplementary secondary output is equal to or greater than the maximum output of the DC / DC conversion circuit, the control circuit controls the operation of the DC / DC conversion circuit so that the supplementary secondary output is continuously output from the DC / DC conversion circuit. charger.

6. 2. The charger according to claim 1, The control circuit includes: determining that it is necessary to limit the output of the storage battery when a positive temperature of the storage battery is within a range from a first high temperature threshold to a first rated upper limit temperature that is higher than the first high temperature threshold, or when a negative temperature of the storage battery is within a range from a first low temperature threshold to a first rated lower limit temperature that is lower than the first low temperature threshold; determining that it is necessary to limit the output of the DC / DC conversion circuit when the positive temperature of a component constituting the DC / DC conversion circuit is within a range from a second high temperature threshold to a second rated upper limit temperature that is higher than the second high temperature threshold, or when the negative temperature of a component constituting the DC / DC conversion circuit is within a range from a second low temperature threshold to a second rated lower limit temperature that is lower than the second low temperature threshold; When the positive temperature of a component constituting the AC / DC conversion circuit is within a range from a third high temperature threshold to a third rated upper limit temperature higher than the third high temperature threshold, or when the negative temperature of a component constituting the AC / DC conversion circuit is within a range from a third low temperature threshold to a third rated lower limit temperature lower than the third low temperature threshold, it is determined that it is necessary to limit the output of the AC / DC conversion circuit. charger.

7. 7. The charger according to claim 6, The control circuit stops the AC / DC conversion circuit and the DC / DC conversion circuit when the positive temperature of the storage battery is higher than the first rated upper limit temperature, when the negative temperature of the storage battery is lower than the first rated lower limit temperature, when the positive temperature of a component constituting the DC / DC conversion circuit is higher than the second rated upper limit temperature, when the negative temperature of a component constituting the DC / DC conversion circuit is lower than the second rated lower limit temperature, when the positive temperature of a component constituting the AC / DC conversion circuit is higher than the third rated upper limit temperature, or when the negative temperature of a component constituting the AC / DC conversion circuit is lower than the third rated lower limit temperature. charger.

8. 2. The charger according to claim 1, The output voltage of the charger is 120 V or less. charger.

9. 2. The charger according to claim 1, The output current of the charger is 75 to 195 A. charger.

10. A vehicle equipped with the charger according to any one of claims 1 to 9.

11. 11. A vehicle as claimed in claim 10, The vehicle is an industrial vehicle. vehicle.

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