WO2011118118A1 - Charging device - Google Patents

Charging device Download PDF

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Publication number
WO2011118118A1
WO2011118118A1 PCT/JP2011/000698 JP2011000698W WO2011118118A1 WO 2011118118 A1 WO2011118118 A1 WO 2011118118A1 JP 2011000698 W JP2011000698 W JP 2011000698W WO 2011118118 A1 WO2011118118 A1 WO 2011118118A1
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WO
WIPO (PCT)
Prior art keywords
voltage
charging
secondary battery
generation circuit
circuit
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Application number
PCT/JP2011/000698
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French (fr)
Japanese (ja)
Inventor
圭秀 金久保
孝一 三上
和久 高田
鈴木　一敬
恭平 加田
Original Assignee
パナソニック株式会社
パナソニック電工株式会社
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Application filed by パナソニック株式会社, パナソニック電工株式会社 filed Critical パナソニック株式会社
Publication of WO2011118118A1 publication Critical patent/WO2011118118A1/en

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/42—Methods or arrangements for servicing or maintenance of secondary cells or secondary half-cells
    • H01M10/44—Methods for charging or discharging
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J2207/00—Indexing scheme relating to details of circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
    • H02J2207/20—Charging or discharging characterised by the power electronics converter
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries

Definitions

  • the present invention relates to a charging device that charges a secondary battery based on supplied power.
  • an LDO Low Drop-out Regulator
  • a linear regulator such as (see, for example, Patent Document 1).
  • stable voltage charging is performed by charging the voltage of the supplied power to a predetermined voltage value and charging the secondary battery using the voltage as a charging voltage.
  • the present invention has been made to solve the above-described problems, and an object of the present invention is to provide a charging device that can reduce power loss and obtain high charging efficiency.
  • a charging device charges a secondary battery based on a charging voltage generation circuit that generates a charging voltage for charging a secondary battery from supplied power, and a charging voltage generated by the charging voltage generation circuit.
  • a charge control circuit that performs current control to perform the control, and the charge voltage generation circuit includes a switching regulator and is configured to change the charge voltage according to a battery voltage of the secondary battery. Yes.
  • the charging voltage for charging the secondary battery is changed according to the battery voltage of the secondary battery, the voltage difference between the battery voltage and the charging voltage of the secondary battery can be reduced, and the power Loss can be reduced.
  • the charging voltage is generated from the supplied power using a switching regulator having higher power conversion efficiency than the linear regulator, power loss due to the voltage difference between the input voltage and the output voltage of the charging voltage generation circuit can be reduced. . Accordingly, it is possible to reduce power loss and obtain high charging efficiency.
  • the supplied power may be power transmitted from the power transmission unit to the power reception unit via a non-contact power feeding device that transmits power between the power transmission unit and the power reception unit.
  • a non-contact power feeding device that transmits power between the power transmission unit and the power reception unit.
  • the charging voltage generation circuit may be configured to generate a voltage obtained by adding an offset voltage having a predetermined voltage value to the battery voltage of the secondary battery as the charging voltage.
  • the charging voltage becomes higher than the battery voltage of the secondary battery by an offset voltage, so the voltage actually applied to the secondary battery is charged due to the variation in the voltage due to the elements included in the charge control circuit and the temperature change.
  • the voltage applied to the secondary battery can be prevented from becoming lower than the battery voltage of the secondary battery. Therefore, it is possible to prevent a charging failure due to a voltage drop.
  • the offset voltage may be 100 mV or more and 600 mV or less.
  • the charge voltage generation circuit may be configured to generate the minimum operation voltage as the charge voltage when the voltage of the secondary battery is equal to or lower than the minimum operation voltage of the charge control circuit.
  • the minimum operation of the charge control circuit is ensured by setting the charge voltage as the minimum operation voltage of the charge control circuit. Power loss can be minimized.
  • the charging device may further include a backflow prevention circuit provided between the charging voltage generation circuit and the secondary battery.
  • a backflow prevention circuit provided between the charging voltage generation circuit and the secondary battery.
  • the backflow prevention circuit includes a rectifying element whose forward direction is a direction from the charging voltage generation circuit to the secondary battery, and a switching element connected in parallel with the rectifying element, and the charging device includes the secondary battery
  • a backflow prevention control circuit for bringing the switching element into a conducting state after the start of charging of the battery and for bringing the backflow preventing circuit into a non-conducting state after the secondary battery is charged.
  • the present invention is configured as described above, and has an effect of reducing power loss and obtaining high charging efficiency.
  • FIG. 1 is a circuit diagram showing a schematic configuration of a non-contact power feeding system to which a charging device according to a first embodiment of the present invention is applied.
  • FIG. 2 is a schematic circuit diagram showing the charging voltage generation circuit shown in FIG.
  • FIG. 3 is a diagram showing the relationship between the charging voltage of the charging device shown in FIG. 1 and the battery voltage of the secondary battery.
  • FIG. 4 is a circuit diagram showing the maximum value selection circuit shown in FIG.
  • FIG. 5 is a circuit diagram showing a schematic configuration of a charging voltage generation circuit of the charging device according to a modification of the first embodiment of the present invention.
  • FIG. 6 is a circuit diagram showing the maximum value selection circuit shown in FIG. FIG.
  • FIG. 7 is a circuit diagram illustrating a schematic configuration of a non-contact power feeding system to which the charging device according to the second embodiment of the present invention is applied.
  • FIG. 8 is a graph showing the time change of the voltage of each part of the charging apparatus shown in FIG.
  • FIG. 9 is a circuit diagram illustrating a schematic configuration of a charging system to which the charging device according to the third embodiment of the present invention is applied.
  • FIG. 1 is a circuit diagram showing a schematic configuration of a non-contact power feeding system to which a charging device according to a first embodiment of the present invention is applied.
  • the non-contact power feeding system 1 of the present embodiment includes a primary side control unit 6 that functions as a power supply control device and a secondary side control unit 7 that functions as a charging device. .
  • An AC power supply 11 is connected to the primary side control unit 6.
  • the primary side control unit 6 includes a power transmission unit 8 for transmitting the power supplied from the AC power source 11 to the secondary side control unit 7, and a power transmission control device 5 for controlling the supply voltage of the power supplied from the AC power source 11. It has.
  • the secondary side control unit 7 is connected to a secondary battery 4 serving as a power source for a device (not shown) including the secondary side control unit 7.
  • the secondary-side control unit 7 generates a charging voltage Vch for charging the secondary battery 4 from the power reception unit 9 that receives the power supplied from the power transmission unit 8 of the primary-side control unit 6 in a contactless manner.
  • a charge control circuit (charger) 3 that performs current control for charging the secondary battery 4 based on the charge voltage Vch generated by the charge voltage generation circuit 2.
  • the power transmission unit 8 of the primary side control unit 6 and the power reception unit 9 of the secondary side control unit 7 transmit power from the power transmission unit 8 on the primary side to the power reception unit 9 on the secondary side. 10 is constituted.
  • the power transmission unit 8 is provided with a primary side coil
  • the power reception unit 9 is provided with a secondary side coil that can be mutually guided to the primary side coil.
  • the power receiving unit 9 is provided with an AC-DC converter (not shown) that converts AC power received from the power transmission unit 8 into DC power.
  • the power receiving unit 9 outputs a DC voltage (Vin) of DC power. This DC voltage becomes the input voltage Vin of the charging voltage generation circuit 2.
  • the charging voltage generation circuit 2 includes a switching regulator that converts the input voltage Vin input from the power receiving unit 9 into a desired charging voltage Vch, and changes the charging voltage Vch according to the battery voltage Vbatt of the secondary battery 4.
  • the charging voltage generation circuit 2 is a switching regulator, for example, boosts or steps down the input voltage Vin from the power receiving unit 9 to a voltage based on the battery voltage Vbatt of the secondary battery 4 and outputs it as a charging voltage Vch.
  • a DC-DC converter 21 is provided.
  • FIG. 2 is a schematic circuit diagram showing the charging voltage generation circuit shown in FIG.
  • the charging voltage generating circuit 2 controls the DC-DC converter 21 and the output voltage of the DC-DC converter 21 (equal to the charging voltage Vch in this embodiment). have.
  • the control circuit 25 is configured to control the output voltage of the DC-DC converter 21 based on the battery voltage Vbatt of the secondary battery 4.
  • the charging voltage generation circuit 2 uses a voltage obtained by adding an offset voltage Vo (described later) to the output voltage of the DC-DC converter 21 (that is, the charging voltage Vch that is the output voltage of the charging voltage generation circuit 2) as the first reference. It has a comparator 23 for comparing with the battery voltage Vbatt of the secondary battery 4 which is a voltage.
  • the control circuit 25 adjusts the output voltage (charge voltage Vch) of the DC-DC converter 21 so that the added voltage (Vch + Vo) becomes the first reference voltage according to the output voltage of the comparator 23.
  • the output voltage of the offset adder 22 that is, the addition voltage (Vch + Vo)
  • the + side of the comparator 23 is
  • the battery voltage Vbatt of the secondary battery 4 is input to the input terminal
  • the addition voltage (Vch + Vo) may be input to the + side input terminal
  • the battery voltage Vbatt may be input to the ⁇ side input terminal.
  • the charging voltage Vch for charging the secondary battery 4 is changed according to the battery voltage Vbatt of the secondary battery 4, the voltage difference between the battery voltage Vbatt and the charging voltage Vch of the secondary battery 4 is The power loss can be reduced.
  • the charging voltage is generated from the supplied power using a switching regulator having higher power conversion efficiency than the linear regulator, power loss due to the voltage difference between the input voltage Vin and the output voltage Vch of the charging voltage generation circuit 2 is reduced. be able to. Accordingly, it is possible to reduce power loss and obtain high charging efficiency.
  • the non-contact electric power feeding system 1 in which high-efficiency power use is required as in the present embodiment by applying the charging device having the above configuration, it is possible to reduce power loss and obtain high charging efficiency. .
  • FIG. 3 is a diagram showing the relationship between the charging voltage of the charging device shown in FIG. 1 and the battery voltage of the secondary battery.
  • FIG. 3A shows a graph of this embodiment
  • FIG. 3B shows a graph in a configuration in which charging is performed by applying a constant voltage as a comparative example.
  • FIG. 3 (b) in the conventional charging device, a predetermined constant voltage that can charge the secondary battery 4 until full charge is used as the charging voltage Vch regardless of the battery voltage Vbatt of the secondary battery 4.
  • the secondary battery 4 was applied.
  • FIG. 3B shows a state in which a charging voltage of 5.0 V is applied.
  • the battery voltage Vbatt of the secondary battery 4 is low (for example, 3.0 V)
  • the difference between the charging voltage Vch and the battery voltage Vbatt is large, resulting in power loss.
  • the area of the shaded portion shown in FIG. 3B represents the magnitude of power loss. As shown in FIG. 3 (b), this power loss decreases as charging progresses and the battery voltage Vbatt increases, but the power loss over the entire charging period increases considerably.
  • the charging voltage Vch of the secondary battery 4 is changed to follow the battery voltage Vbatt of the secondary battery 4. Therefore, the voltage difference between the battery voltage Vbatt and the charging voltage Vch can be reduced, and the power loss (area of the hatched portion in FIG. 3A) is compared with the conventional configuration as shown in FIG. Can be reduced.
  • the charging voltage generation circuit 2 in the present embodiment adds an offset voltage Vo of several hundred mV (300 mV in FIG. 3A) to the battery voltage Vbatt of the secondary battery 4.
  • the combined voltage is generated as a charging voltage.
  • the charging voltage generation circuit 2 outputs 3.8 V as the charging voltage Vch
  • the battery voltage Vbatt of the secondary battery 4 is 4.2 V
  • the charging voltage generation circuit 2 outputs 4 as the charging voltage Vch. .5V is output.
  • the charging voltage generation circuit 2 has an offset adder 22 that adds an offset voltage Vo having a predetermined voltage value to the charging voltage Vch, and the added voltage ( Vch + Vo) is input.
  • the charging voltage Vch which is the output voltage of the DC-DC converter 21
  • the battery voltage Vbatt of the secondary battery 4 that is the first reference voltage by the offset voltage Vo.
  • the secondary battery 4 since the charging voltage Vch is higher than the battery voltage Vbatt of the secondary battery 4 by the offset voltage Vo, the secondary battery 4 is actually caused by variations in the elements included in the charging control circuit 3 and the voltage due to temperature changes.
  • the voltage applied to the secondary battery 4 is prevented from becoming lower than the battery voltage Vbatt of the secondary battery 4 even if the voltage applied to the battery is lower than the charge voltage Vch generated by the charge voltage generation circuit 2. Can do. Therefore, it is possible to prevent a charging failure due to a voltage drop.
  • the offset voltage Vo is not particularly limited as long as it is a voltage that can tolerate variations in the voltage assumed depending on elements included in the charge control circuit 3 and the use temperature environment, but is assumed to be a preferable range of 100 mV to 600 mV.
  • the charging voltage generation circuit 1 in the present embodiment has a case where the battery voltage Vbatt of the secondary battery 4 is equal to or lower than the minimum operating voltage VL (3.3 V) of the charging control circuit 3.
  • the minimum operating voltage VL is generated as the charging voltage Vch.
  • the charging voltage generation circuit 2 generates a voltage source 26 that generates a voltage (VL ⁇ Vo: 3.0V) that is lower than the lowest operating voltage VL that is the second reference voltage by the offset voltage Vo.
  • the battery voltage Vbatt of the secondary battery 4 that is the first reference voltage and the second reference voltage generated by the voltage source 26, and the higher one of the first reference voltage and the second reference voltage. Is output as the reference voltage Vref of the comparator 23.
  • the comparator 23 adds the added voltage (Vch + Vo) to the battery voltage Vbatt. If the battery voltage Vbatt of the secondary battery 4 is a voltage equal to or lower than the second reference voltage (VL ⁇ Vo) generated by the voltage source 26, the comparator 23 adds the added voltage (Vch + Vo) to the second reference voltage. It is compared with (VL-Vo). Therefore, if the battery voltage Vbatt of the secondary battery 4 is higher than the second reference voltage (VL-Vo), the DC-DC converter 21 is such that the charging voltage Vch is higher than the battery voltage Vbatt by the offset voltage Vo (see FIG.
  • the DC-DC converter 21 is charged with the charging voltage Vch. Is controlled to be the minimum operating voltage VL of the charging control circuit 3 (3.3 V in the example of FIG. 3).
  • the charging voltage Vch is set to the minimum operating voltage VL of the charging control circuit 3, thereby The power loss can be suppressed as much as possible while ensuring the limit operation.
  • the charging voltage Vch is constant (5.0 V)
  • the charging voltage Vch is constant (5.0 V)
  • the battery voltage Vbatt of the secondary battery 4 and the minimum operating voltage VL of the charging control circuit 3 There is no relationship, and a useless voltage is applied to operate the charge control circuit 3.
  • power loss can be reduced by applying a minimum voltage while considering the operation of the charge control circuit 3 during charging.
  • FIG. 4 is a circuit diagram showing the maximum value selection circuit shown in FIG.
  • the maximum value selection circuit 24 selectively selects either the first reference voltage (battery voltage Vbatt) or the second reference voltage (VL-Vo) for the comparator 23.
  • the switching circuit 241 is configured to connect the higher one of the first and second reference voltages compared in the comparator 242 to the comparator 23.
  • the voltage source 26 has been described as having the second reference voltage (VL-Vo).
  • a voltage source such as a band gap voltage (about 1.2 V) is used as the second reference voltage.
  • the voltage may be increased or decreased to the voltage (VL ⁇ Vo) and compared with the addition voltage (Vch + Vo) to be controlled.
  • the addition voltage (Vch + Vo) to be controlled may be stepped down or boosted to a corresponding voltage and then compared with the second reference voltage (band gap voltage) generated by the voltage source 26.
  • FIG. 5 is a circuit diagram showing a schematic configuration of a charging voltage generation circuit of the charging device according to a modification of the first embodiment of the present invention.
  • the same reference numerals are given to the same components as those in the first embodiment, and the description thereof is omitted.
  • the charging device (secondary control unit 7B) in the present modification is different from the first embodiment in that the offset adder 22 is a battery of the secondary battery 4 in the charging voltage generation circuit 32. It is configured to output an addition voltage (Vbatt + Vo) obtained by adding the offset voltage Vo to the voltage Vbatt, and the comparator 23 is an output voltage of the DC-DC converter 21 (that is, an output voltage of the charging voltage generation circuit 2).
  • the charging voltage Vch) is compared with the added voltage (Vbatt + Vo). That is, the first reference voltage becomes the above-mentioned addition voltage (Vbatt + Vo).
  • the control circuit 25 adjusts the output voltage (charge voltage Vch) of the DC-DC converter 21 according to the output voltage of the comparator 23 so that the charge voltage Vch becomes the addition voltage (Vbatt + Vo) which is the first reference voltage. .
  • the charging voltage Vch which is the output voltage of the DC-DC converter 21 is the addition of the battery voltage Vbatt and the offset voltage Vo of the secondary battery 4 that is the first reference voltage. Feedback control is performed so that the voltage becomes (Vbatt + Vo).
  • the charging voltage Vch is higher than the battery voltage Vbatt of the secondary battery 4 by the offset voltage Vo. Therefore, the charging voltage Vch is actually caused by variations in the elements included in the charging control circuit 3 and the voltage due to temperature changes. Even if the voltage applied to the secondary battery 4 drops below the charging voltage Vch generated by the charging voltage generation circuit 2, the voltage applied to the secondary battery 4 becomes lower than the battery voltage Vbatt of the secondary battery 4. This can be prevented. Therefore, it is possible to prevent a charging failure due to a voltage drop.
  • the charging voltage generation circuit 32 is generated by the voltage source 34 that generates the lowest operating voltage VL (3.3 V) that is the second reference voltage, and the addition voltage (Vbatt + Vo) that is the first reference voltage and the voltage source 34. And a maximum value selection circuit 33 that outputs the higher one of the first reference voltage and the second reference voltage as the reference voltage Vref of the comparator 23.
  • the comparator 23 The charging voltage Vch is compared with the addition voltage (Vbatt + Vo), and if the addition voltage (Vbatt + Vo) is equal to or lower than the minimum operating voltage VL of the charging control circuit 3 generated by the voltage source 34, the comparator 23 charges the charging voltage Vch. Therefore, if the added voltage (Vbatt + Vo) is higher than the lowest operating voltage VL, the DC-DC converter 21 has a charging voltage Vch higher than the battery voltage Vbatt by the offset voltage Vo. (Vbatt + 0.3V in the example of FIG.
  • the DC-DC converter 21 is controlled so that the charging voltage Vch becomes the minimum operating voltage VL of the charging control circuit 3 (3.3 V in the example of FIG. 3).
  • the charge voltage Vch is used as the charge control circuit 3.
  • FIG. 6 is a circuit diagram showing the maximum value selection circuit shown in FIG.
  • the maximum value selection circuit 33 is a switching circuit that selectively connects either the first reference voltage (Vbatt + Vo) or the second reference voltage (VL) to the comparator 23. 331 and a comparator 332 that compares the battery voltage Vbatt of the secondary battery 4 and the minimum operating voltage VL.
  • the switching circuit 331 connects the first reference voltage (Vbatt + Vo) to the comparator 23 if the battery voltage Vbatt is higher than the battery voltage Vbatt and the minimum operating voltage VL compared in the comparator 332, and the minimum operating voltage VL is set. If it is higher, the second reference voltage VL (voltage source 34) is connected to the comparator 23.
  • FIG. 7 is a circuit diagram illustrating a schematic configuration of a non-contact power feeding system to which the charging device according to the second embodiment of the present invention is applied.
  • the power transmission unit of the non-contact power feeding system is the same as that of the first embodiment, and therefore, illustration is omitted and only the power reception unit is shown.
  • the same components as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.
  • the non-contact power feeding system 40 in the present embodiment is different from the first embodiment in that the charging device (secondary control unit 7 ⁇ / b> C) includes the charging voltage generation circuit 42, the secondary battery 4, and the like. Is provided with a backflow prevention circuit 43 provided therebetween.
  • the backflow prevention circuit 43 includes a rectifying element 432 having a forward direction from the charging voltage generation circuit 2 toward the secondary battery 4, a switching element 431 connected in parallel with the rectifying element 432, a secondary There is a backflow prevention control circuit 44 that turns on the switching element 431 after the battery 4 starts charging and turns off the backflow prevention circuit 43 after the secondary battery 4 is charged.
  • the charging device further includes a backflow prevention control circuit 44 that turns on the backflow prevention circuit 43 during charging of the secondary battery 4 and turns off the backflow prevention circuit 43 after charging of the secondary battery 4. is doing.
  • the switching element 431 in the present embodiment is a MOS transistor (transistor) in which two main terminals (drain terminal and source terminal) are connected between the output side of the charging voltage generation circuit 42 and the input side of the charging control circuit 3. (Hereinafter referred to as MOS transistor 431).
  • the rectifying element 432 is connected between the main terminals of the MOS transistor 431 and is configured by a diode having a forward direction from the charging voltage generation circuit 42 toward the charging control circuit 3.
  • the backflow prevention circuit 43 has a resistor 433 connected between the main terminal (source terminal) on the input side of the charge control circuit 3 of the MOS transistor 431 and the control terminal (gate terminal).
  • the output side of the backflow prevention control circuit 44 is connected to the control terminal (gate terminal) of the MOS transistor 431, and the MOS transistor 431 is turned on or off in accordance with the control voltage Vcont output from the backflow prevention control circuit 44.
  • the operation of the prevention circuit 43 is controlled.
  • the backflow prevention control circuit 44 is configured by a logic circuit, and operates according to the charging status voltage Ven that is output according to the charging voltage generation circuit 42 being charged or not charged.
  • FIG. 7 shows an example in which the MOS transistor 431 uses a P-type MOSFET, it may be an N-type or another type of FET.
  • FIG. 8 is a graph showing the time change of the voltage of each part of the charging apparatus shown in FIG.
  • the input voltage Vin to the charging voltage generation circuit 42 increases.
  • the charging voltage generation circuit 42 is transmitted from the primary side control unit 6 together with the supplied power to start charging the secondary battery 4.
  • a control sequence such as data authentication processing is executed.
  • the charging voltage generation circuit 42 waits without starting charging (see the waiting time at Ven in FIG. 8).
  • the charging voltage generation circuit 42 After completion of the predetermined control sequence (or after the elapse of a predetermined standby time), the charging voltage generation circuit 42 increases the output voltage Vout of the DC-DC converter 21 and starts charging the secondary battery 4. At this time, the state of charge state voltage Ven changes from the first voltage (L level voltage) to a second voltage (H level voltage higher than L level) different from the first voltage. As a result, the charging voltage generation circuit 42 notifies the backflow prevention control circuit 44 of the start of charging. Since the MOS transistor 431 remains off immediately after the start of charging, the power output from the charging voltage generation circuit 42 is transmitted to the charging control circuit 3 through the rectifying element 432.
  • the output voltage Vout of the charging voltage generation circuit 2 is lower than the battery voltage Vbatt of the secondary battery 4 when the MOS transistor 431 is turned on, a backflow current flows from the secondary battery 4 to the charging voltage generation circuit 42. May flow.
  • charging can be started through the rectifying element 432 while preventing a reverse current by setting the MOS transistor 431 in a non-conductive state.
  • the charging voltage Vch reaches only a voltage lower than the output voltage Vout of the charging voltage generation circuit 42 by the resistance due to the resistance of the rectifying element 432.
  • the backflow prevention control circuit 44 changes the control voltage Vcont from the first voltage (L level voltage) to the first voltage at a predetermined timing. State transition is made to a second voltage different from L (voltage of H level higher than L level).
  • the predetermined timing is, for example, at the stage when the control sequence of the backflow prevention control circuit 44 is completed or after a predetermined standby time has elapsed (for example, when the control sequence ends and / or the output voltage Vout of the charging voltage generation circuit 42 rises). After sufficient time).
  • the MOS transistor 431 When the control voltage Vcont transitions to the second voltage H, the MOS transistor 431 is turned on. As a result, the main terminals of the MOS transistor 431 become conductive, and the internal resistance of the MOS transistor 431 is sufficiently smaller than the resistance of the rectifying element 432, so that the output voltage Vout and the charging voltage Vch of the charging voltage generation circuit 42 are The voltage is almost the same.
  • a voltage higher than the battery voltage Vbatt of the secondary battery 4 is applied from the DC-DC converter 21 of the charge voltage generation circuit 42, a reverse current from the secondary battery 4 is applied to the charge voltage generation circuit 42. There is no flow.
  • the backflow prevention control circuit 44 changes the state of the control voltage Vcont from the second voltage H to the first voltage L, and turns off the MOS transistor 431. To do.
  • the main terminals of the MOS transistor 431 become non-conductive, and the main terminal (source terminal) and the control terminal (gate terminal) on the charge control circuit 3 side connected by the resistor 433 have the same voltage. Therefore, a reverse current flows from the secondary battery 4 to the DC-DC converter 21 of the charging voltage generation circuit 42 even when the battery voltage Vbatt of the secondary battery 4 becomes higher than the voltage of the charging voltage generation circuit 42 after the end of charging. This can be prevented.
  • the output voltage Vout of the charging voltage generation circuit 2 becomes high and no reverse current flows through the charging voltage generation circuit 2, so that the MOS transistor 431 serving as a switching element is made conductive.
  • the charging voltage is generated. Since a backflow current may flow through the circuit 2, it is possible to effectively prevent a backflow current from flowing into the charging voltage generation circuit 2 by making the MOS transistor 431 non-conductive.
  • the configuration in which the backflow prevention circuit 43 includes the MOS transistor 431 and the rectifying element 432 as switching elements has been described.
  • the configuration without the rectifying element 432 (the backflow prevention circuit 43 has a switching element).
  • the charging device may be configured to include a backflow prevention control circuit 44 that controls ON or OFF of the switching element), or may include only the rectifying element 432 (configuration that does not include the switching element and the backflow prevention control circuit 44). It is good.
  • FIG. 9 is a circuit diagram illustrating a schematic configuration of a charging system to which the charging device according to the third embodiment of the present invention is applied.
  • the same components as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.
  • the charging system 50 in the present embodiment is different from the first embodiment in that the charging device 7D is connected to the AC power supply 11 and the power supplied to the charging voltage generation circuit 2 of the charging device 7D. Is the power output from the AC power supply 11.
  • the charging device 7D of the charging system 50 includes an AC-DC converter 51 that converts AC power of the AC power supply 11 into DC power.
  • the AC-DC converter 51 outputs a DC voltage (Vin) based on DC power. This DC voltage becomes the input voltage Vin of the charging voltage generation circuit 2.
  • the charging device of the present invention can be widely applied as a charging device for charging the secondary battery 4 regardless of the supplied power.
  • the configuration in which the AC power supply 11 is connected has been described. However, a DC power supply may be connected. In this case, it is not necessary to provide the AC-DC converter 51 in the charging device.
  • the charging device of the present invention is useful for reducing power loss and obtaining high charging efficiency.
  • it is useful for reducing power loss and obtaining high charging efficiency.

Abstract

Provided is a charging device wherein it is possible to minimize power loss and to achieve high charging efficiency. Disclosed is a charging device (7) provided with: a charging voltage generating circuit (2) which generates, from a power supply, a charging voltage (Vch) for charging a secondary battery (4); and a charging control circuit (3) which controls the current for charging the secondary battery (4) on the basis of the charging voltage (Vch) generated by means of the charging voltage generating circuit (2). The charging voltage generating circuit (2) comprises a switching regulator (21), and changes the charging voltage (Vch) in accordance with the battery voltage (Vbatt) of the secondary battery (4).

Description

充電装置Charger
　本発明は、供給電力に基づいて二次電池を充電する充電装置に関する。 The present invention relates to a charging device that charges a secondary battery based on supplied power.
　供給電力に基づいてリチウムイオン（lithium-ion）電池等の二次電池を充電する充電装置においては、高精度に充電電圧を制御するために、ＬＤＯ（Low Drop-out Regulator：ロードロップアウトレギュレータ）等のリニアレギュレータ（linear regulator）を用いることが知られている（例えば特許文献１参照）。 In a charging device that charges a secondary battery such as a lithium-ion battery based on the supplied power, an LDO (Low Drop-out Regulator) is used to control the charging voltage with high accuracy. It is known to use a linear regulator such as (see, for example, Patent Document 1).
　上記特許文献１の構成においては、供給電力による電圧を予め定められた電圧値に定電圧化し、当該電圧を充電電圧として二次電池を充電することにより安定した充電を行うこととしている。 In the configuration of Patent Document 1, stable voltage charging is performed by charging the voltage of the supplied power to a predetermined voltage value and charging the secondary battery using the voltage as a charging voltage.
特開２００８－１７８１９６号公報JP 2008-178196 A
　しかし、上記のような構成においては、以下のような問題がある。まず、特許文献１のようなリニアレギュレータを用いて充電電圧を制御すると、リニアレギュレータの入力電圧（例えば１０Ｖ）と出力電圧（例えば５Ｖ）との電圧差により電力損失が生じてしまう問題がある。さらに、特許文献１のように、充電電圧を一定の電圧（５Ｖ）とすると、二次電池の電池電圧が低い場合（例えば３Ｖである場合）に、充電電圧と電池電圧との電圧差により電力損失が生じてしまう問題がある。 However, the above configuration has the following problems. First, when the charging voltage is controlled using a linear regulator as in Patent Document 1, there is a problem that power loss occurs due to a voltage difference between an input voltage (for example, 10 V) and an output voltage (for example, 5 V) of the linear regulator. Further, as in Patent Document 1, when the charging voltage is a constant voltage (5 V), when the battery voltage of the secondary battery is low (for example, 3 V), power is generated by the voltage difference between the charging voltage and the battery voltage. There is a problem that loss occurs.
　特に、１次側コイルと２次側コイルとの間で電力を非接触で伝送する非接触給電システムにおいては、高効率な電力利用が求められるため、電力損失の低減は重要な課題である。 Especially, in a non-contact power feeding system that transmits power in a non-contact manner between a primary side coil and a secondary side coil, high-efficiency power use is required, and thus reduction of power loss is an important issue.
　本発明は、以上のような課題を解決すべくなされたものであり、電力損失を低減して高い充電効率を得ることができる充電装置を提供することを目的とする。 The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a charging device that can reduce power loss and obtain high charging efficiency.
　本発明に係る充電装置は、供給電力から二次電池を充電するための充電電圧を生成する充電電圧生成回路と、前記充電電圧生成回路で生成された充電電圧に基づいて前記二次電池を充電するための電流制御を行う充電制御回路とを備え、前記充電電圧生成回路は、スイッチングレギュレータ（switching regulator）を含み、前記二次電池の電池電圧に応じて前記充電電圧を変化させるよう構成されている。 A charging device according to the present invention charges a secondary battery based on a charging voltage generation circuit that generates a charging voltage for charging a secondary battery from supplied power, and a charging voltage generated by the charging voltage generation circuit. A charge control circuit that performs current control to perform the control, and the charge voltage generation circuit includes a switching regulator and is configured to change the charge voltage according to a battery voltage of the secondary battery. Yes.
　上記構成によれば、二次電池の電池電圧に応じて当該二次電池を充電する充電電圧を変化させるため、二次電池の電池電圧と充電電圧との電圧差を少なくすることができ、電力損失を低減させることができる。しかも、リニアレギュレータよりも電力変換効率の高いスイッチングレギュレータを用いて供給電力から充電電圧が生成されるため、充電電圧生成回路の入力電圧と出力電圧との電圧差による電力損失を低減させることができる。従って、電力損失を低減して高い充電効率を得ることができる。 According to the above configuration, since the charging voltage for charging the secondary battery is changed according to the battery voltage of the secondary battery, the voltage difference between the battery voltage and the charging voltage of the secondary battery can be reduced, and the power Loss can be reduced. In addition, since the charging voltage is generated from the supplied power using a switching regulator having higher power conversion efficiency than the linear regulator, power loss due to the voltage difference between the input voltage and the output voltage of the charging voltage generation circuit can be reduced. . Accordingly, it is possible to reduce power loss and obtain high charging efficiency.
　前記供給電力は、送電部と受電部との間で電力を伝送する非接触給電装置を介して前記送電部から前記受電部へ送られた電力であってもよい。これにより、高効率な電力利用が求められる非接触給電システムにおいて、電力損失を低減して高い充電効率を得ることができる。 The supplied power may be power transmitted from the power transmission unit to the power reception unit via a non-contact power feeding device that transmits power between the power transmission unit and the power reception unit. As a result, in a non-contact power feeding system that requires highly efficient power use, it is possible to reduce power loss and obtain high charging efficiency.
　前記充電電圧生成回路は、前記二次電池の電池電圧に予め定められた電圧値を有するオフセット電圧を足し合わせた電圧を前記充電電圧として生成するよう構成されてもよい。これにより、充電電圧が二次電池の電池電圧よりオフセット電圧分高い電圧となるため、充電制御回路等に含まれる素子や温度変化による電圧のばらつきにより実際に二次電池に印加される電圧が充電電圧生成回路で生成された充電電圧より低下しても当該二次電池に印加される電圧が二次電池の電池電圧より低くなることを防止することができる。従って、電圧低下による充電不良を防止することができる。 The charging voltage generation circuit may be configured to generate a voltage obtained by adding an offset voltage having a predetermined voltage value to the battery voltage of the secondary battery as the charging voltage. As a result, the charging voltage becomes higher than the battery voltage of the secondary battery by an offset voltage, so the voltage actually applied to the secondary battery is charged due to the variation in the voltage due to the elements included in the charge control circuit and the temperature change. Even when the voltage is lower than the charging voltage generated by the voltage generation circuit, the voltage applied to the secondary battery can be prevented from becoming lower than the battery voltage of the secondary battery. Therefore, it is possible to prevent a charging failure due to a voltage drop.
　前記オフセット電圧は、１００ｍＶ以上６００ｍＶ以下であってもよい。 The offset voltage may be 100 mV or more and 600 mV or less.
　前記充電電圧生成回路は、前記二次電池の電圧が前記充電制御回路の最低動作電圧以下である場合に、前記最低動作電圧を前記充電電圧として生成するよう構成されてもよい。これにより、二次電池の電池電圧が充電制御回路が動作しない電圧である場合には、充電電圧を充電制御回路の最低動作電圧とすることにより、充電制御回路の最低限の動作を確保しつつ電力損失を極力抑えることができる。 The charge voltage generation circuit may be configured to generate the minimum operation voltage as the charge voltage when the voltage of the secondary battery is equal to or lower than the minimum operation voltage of the charge control circuit. Thus, when the battery voltage of the secondary battery is a voltage at which the charge control circuit does not operate, the minimum operation of the charge control circuit is ensured by setting the charge voltage as the minimum operation voltage of the charge control circuit. Power loss can be minimized.
　前記充電装置は、前記充電電圧生成回路と前記二次電池との間に設けられた逆流防止回路をさらに備えてもよい。これにより、二次電池から充電電圧生成回路へ逆流電流が流れることを防止することができる。従って、二次電池の充電後、電池電圧が充電電圧生成回路の電圧より高くなっても、充電電圧生成回路へ逆流電流が流れることを防止することができる。 The charging device may further include a backflow prevention circuit provided between the charging voltage generation circuit and the secondary battery. Thereby, it is possible to prevent a reverse current from flowing from the secondary battery to the charging voltage generation circuit. Therefore, even if the battery voltage becomes higher than the voltage of the charging voltage generation circuit after charging the secondary battery, it is possible to prevent a backflow current from flowing to the charging voltage generation circuit.
　前記逆流防止回路は、充電電圧生成回路から二次電池へ向かう方向を順方向とする整流素子と、前記整流素子と並列に接続されたスイッチング素子とを有し、前記充電装置は、前記二次電池の充電開始後に前記スイッチング素子を導通状態にし、前記二次電池の充電後は前記逆流防止回路を非導通状態にする逆流防止制御回路を有していてもよい。これにより、二次電池の充電開始後は、充電電圧生成回路の出力電圧が高くなり充電電圧生成回路に逆流電流が流れることはないため、スイッチング素子を導通状態にすることにより二次電池への電力供給を促進させるように動作する一方、充電終了後、二次電池の電池電圧より充電電圧生成回路の出力電圧が低くなると充電電圧生成回路に逆流電流が流れるおそれがあるため、スイッチング素子を非導通状態にすることにより充電電圧生成回路へ逆流電流が流れることを有効に防止することができる。 The backflow prevention circuit includes a rectifying element whose forward direction is a direction from the charging voltage generation circuit to the secondary battery, and a switching element connected in parallel with the rectifying element, and the charging device includes the secondary battery There may be provided a backflow prevention control circuit for bringing the switching element into a conducting state after the start of charging of the battery and for bringing the backflow preventing circuit into a non-conducting state after the secondary battery is charged. As a result, after the secondary battery starts charging, the output voltage of the charging voltage generation circuit becomes high and no backflow current flows through the charging voltage generation circuit. While operating to promote power supply, if the output voltage of the charging voltage generation circuit becomes lower than the battery voltage of the secondary battery after charging, a reverse current may flow through the charging voltage generation circuit. By making the conductive state, it is possible to effectively prevent a reverse current from flowing to the charging voltage generation circuit.
　本発明の上記目的、他の目的、特徴、及び利点は、添付図面参照の下、以下の好適な実施態様の詳細な説明から明らかにされる。 The above object, other objects, features, and advantages of the present invention will become apparent from the following detailed description of preferred embodiments with reference to the accompanying drawings.
　本発明は以上に説明したように構成され、電力損失を低減して高い充電効率を得ることができるという効果を奏する。 The present invention is configured as described above, and has an effect of reducing power loss and obtaining high charging efficiency.
図１は、本発明の第１実施形態に係る充電装置が適用された非接触給電システムの概略構成を示す回路図である。FIG. 1 is a circuit diagram showing a schematic configuration of a non-contact power feeding system to which a charging device according to a first embodiment of the present invention is applied. 図２は、図１に示される充電電圧生成回路を示す概略回路図である。FIG. 2 is a schematic circuit diagram showing the charging voltage generation circuit shown in FIG. 図３は、図１に示す充電装置の充電電圧と二次電池の電池電圧との関係を示す図である。FIG. 3 is a diagram showing the relationship between the charging voltage of the charging device shown in FIG. 1 and the battery voltage of the secondary battery. 図４は、図２に示される最大値選択回路を示す回路図である。FIG. 4 is a circuit diagram showing the maximum value selection circuit shown in FIG. 図５は、本発明の第１実施形態の変形例における充電装置の充電電圧生成回路の概略構成を示す回路図である。FIG. 5 is a circuit diagram showing a schematic configuration of a charging voltage generation circuit of the charging device according to a modification of the first embodiment of the present invention. 図６は、図５に示される最大値選択回路を示す回路図である。FIG. 6 is a circuit diagram showing the maximum value selection circuit shown in FIG. 図７は、本発明の第２実施形態における充電装置が適用された非接触給電システムの概略構成を示す回路図である。FIG. 7 is a circuit diagram illustrating a schematic configuration of a non-contact power feeding system to which the charging device according to the second embodiment of the present invention is applied. 図８は、図７に示される充電装置の各部の電圧の時間変化を示すグラフである。FIG. 8 is a graph showing the time change of the voltage of each part of the charging apparatus shown in FIG. 図９は、本発明の第３実施形態における充電装置が適用された充電システムの概略構成を示す回路図である。FIG. 9 is a circuit diagram illustrating a schematic configuration of a charging system to which the charging device according to the third embodiment of the present invention is applied.
　以下、本発明の実施の形態を、図面を参照しながら説明する。なお、以下では全ての図を通じて同一又は相当する要素には同一の参照符号を付して、その重複する説明を省略する。 Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the same or corresponding elements are denoted by the same reference symbols throughout the drawings, and redundant description thereof is omitted.
　＜第１実施形態＞
　まず、本発明の第１実施形態に係る充電装置が適用された非接触給電システムについて説明する。図１は、本発明の第１実施形態に係る充電装置が適用された非接触給電システムの概略構成を示す回路図である。 <First Embodiment>
First, a non-contact power feeding system to which the charging device according to the first embodiment of the present invention is applied will be described. FIG. 1 is a circuit diagram showing a schematic configuration of a non-contact power feeding system to which a charging device according to a first embodiment of the present invention is applied.
　図１に示されるように、本実施形態の非接触給電システム１は、電源制御装置として機能する１次側制御ユニット６と、充電装置として機能する２次側制御ユニット７とを有している。１次側制御ユニット６には交流電源１１が接続されている。１次側制御ユニット６は、交流電源１１からの供給電力を２次側制御ユニット７へ送電するための送電部８と、交流電源１１からの供給電力の給電電圧を制御する送電制御装置５とを備えている。 As shown in FIG. 1, the non-contact power feeding system 1 of the present embodiment includes a primary side control unit 6 that functions as a power supply control device and a secondary side control unit 7 that functions as a charging device. . An AC power supply 11 is connected to the primary side control unit 6. The primary side control unit 6 includes a power transmission unit 8 for transmitting the power supplied from the AC power source 11 to the secondary side control unit 7, and a power transmission control device 5 for controlling the supply voltage of the power supplied from the AC power source 11. It has.
　２次側制御ユニット７には、２次側制御ユニット７を含む機器（図示せず）の電源となる二次電池４が接続されている。２次側制御ユニット７は、１次側制御ユニット６の送電部８からの供給電力を非接触で受電する受電部９と、供給電力から二次電池４を充電するための充電電圧Ｖｃｈを生成する充電電圧生成回路２と、充電電圧生成回路２で生成された充電電圧Ｖｃｈに基づいて二次電池４を充電するための電流制御を行う充電制御回路（充電器）３とを備えている。 The secondary side control unit 7 is connected to a secondary battery 4 serving as a power source for a device (not shown) including the secondary side control unit 7. The secondary-side control unit 7 generates a charging voltage Vch for charging the secondary battery 4 from the power reception unit 9 that receives the power supplied from the power transmission unit 8 of the primary-side control unit 6 in a contactless manner. And a charge control circuit (charger) 3 that performs current control for charging the secondary battery 4 based on the charge voltage Vch generated by the charge voltage generation circuit 2.
　１次側制御ユニット６の送電部８と２次側制御ユニット７の受電部９とは、電力を１次側である送電部８から２次側である受電部９へ伝送する非接触給電装置１０を構成している。送電部８には、１次側コイルが設けられ、受電部９には、１次側コイルに相互誘導可能な２次側コイルが設けられており、送電部８から受電部９へ相互誘導作用により電力を非接触で伝送する。また、受電部９には、送電部８から受電された交流電力を直流電力に変換するＡＣ－ＤＣ変換器（図示せず）が設けられている。受電部９は、直流電力の直流電圧（Ｖｉｎ）を出力している。この直流電圧が充電電圧生成回路２の入力電圧Ｖｉｎとなる。 The power transmission unit 8 of the primary side control unit 6 and the power reception unit 9 of the secondary side control unit 7 transmit power from the power transmission unit 8 on the primary side to the power reception unit 9 on the secondary side. 10 is constituted. The power transmission unit 8 is provided with a primary side coil, and the power reception unit 9 is provided with a secondary side coil that can be mutually guided to the primary side coil. To transmit power in a contactless manner. In addition, the power receiving unit 9 is provided with an AC-DC converter (not shown) that converts AC power received from the power transmission unit 8 into DC power. The power receiving unit 9 outputs a DC voltage (Vin) of DC power. This DC voltage becomes the input voltage Vin of the charging voltage generation circuit 2.
　ここで、充電電圧生成回路２は、受電部９から入力される入力電圧Ｖｉｎを所望の充電電圧Ｖｃｈに変換するスイッチングレギュレータを含み、二次電池４の電池電圧Ｖｂａｔｔに応じて充電電圧Ｖｃｈを変化させるよう構成される。具体的には、充電電圧生成回路２は、スイッチングレギュレータとして、例えば、受電部９からの入力電圧Ｖｉｎを二次電池４の電池電圧Ｖｂａｔｔに基づいた電圧に昇圧又は降圧して充電電圧Ｖｃｈとして出力するＤＣ－ＤＣコンバータ(converter)２１を有している。 Here, the charging voltage generation circuit 2 includes a switching regulator that converts the input voltage Vin input from the power receiving unit 9 into a desired charging voltage Vch, and changes the charging voltage Vch according to the battery voltage Vbatt of the secondary battery 4. Configured to let Specifically, the charging voltage generation circuit 2 is a switching regulator, for example, boosts or steps down the input voltage Vin from the power receiving unit 9 to a voltage based on the battery voltage Vbatt of the secondary battery 4 and outputs it as a charging voltage Vch. A DC-DC converter 21 is provided.
　図２は、図１に示される充電電圧生成回路を示す概略回路図である。図２に示されるように、充電電圧生成回路２は、上記のＤＣ－ＤＣコンバータ２１と、ＤＣ－ＤＣコンバータ２１の出力電圧（本実施形態においては充電電圧Ｖｃｈに等しい）を制御する制御回路２５を有している。制御回路２５は、二次電池４の電池電圧Ｖｂａｔｔに基づいてＤＣ－ＤＣコンバータ２１の出力電圧を制御するよう構成されている。このために、充電電圧生成回路２は、ＤＣ－ＤＣコンバータ２１の出力電圧（すなわち充電電圧生成回路２の出力電圧である充電電圧Ｖｃｈ）に後述するオフセット電圧Ｖｏが加算された電圧を第１基準電圧である二次電池４の電池電圧Ｖｂａｔｔと比較する比較器２３を有している。制御回路２５は、比較器２３の出力電圧に応じて、加算電圧（Ｖｃｈ＋Ｖｏ）が第１基準電圧となるようにＤＣ－ＤＣコンバータ２１の出力電圧（充電電圧Ｖｃｈ）を調整する。なお、本実施形態においては、図２に示すように、比較器２３の－側入力端子にオフセット加算器２２の出力電圧（すなわち、加算電圧（Ｖｃｈ＋Ｖｏ））が入力され、比較器２３の＋側入力端子に二次電池４の電池電圧Ｖｂａｔｔが入力されているが、＋側入力端子に加算電圧（Ｖｃｈ＋Ｖｏ）が入力され、－側入力端子に電池電圧Ｖｂａｔｔが入力されてもよい。 FIG. 2 is a schematic circuit diagram showing the charging voltage generation circuit shown in FIG. As shown in FIG. 2, the charging voltage generating circuit 2 controls the DC-DC converter 21 and the output voltage of the DC-DC converter 21 (equal to the charging voltage Vch in this embodiment). have. The control circuit 25 is configured to control the output voltage of the DC-DC converter 21 based on the battery voltage Vbatt of the secondary battery 4. For this purpose, the charging voltage generation circuit 2 uses a voltage obtained by adding an offset voltage Vo (described later) to the output voltage of the DC-DC converter 21 (that is, the charging voltage Vch that is the output voltage of the charging voltage generation circuit 2) as the first reference. It has a comparator 23 for comparing with the battery voltage Vbatt of the secondary battery 4 which is a voltage. The control circuit 25 adjusts the output voltage (charge voltage Vch) of the DC-DC converter 21 so that the added voltage (Vch + Vo) becomes the first reference voltage according to the output voltage of the comparator 23. In the present embodiment, as shown in FIG. 2, the output voltage of the offset adder 22 (that is, the addition voltage (Vch + Vo)) is input to the − side input terminal of the comparator 23, and the + side of the comparator 23 is Although the battery voltage Vbatt of the secondary battery 4 is input to the input terminal, the addition voltage (Vch + Vo) may be input to the + side input terminal, and the battery voltage Vbatt may be input to the − side input terminal.
　上記構成によれば、二次電池４の電池電圧Ｖｂａｔｔに応じて当該二次電池４を充電する充電電圧Ｖｃｈを変化させるため、二次電池４の電池電圧Ｖｂａｔｔと充電電圧Ｖｃｈとの電圧差を小さくすることができ、電力損失を低減させることができる。しかも、リニアレギュレータよりも電力変換効率の高いスイッチングレギュレータを用いて供給電力から充電電圧が生成されるため、充電電圧生成回路２の入力電圧Ｖｉｎと出力電圧Ｖｃｈとの電圧差による電力損失を低減させることができる。従って、電力損失を低減して高い充電効率を得ることができる。また、本実施形態のように、高効率な電力利用が求められる非接触給電システム１においても、上記構成の充電装置を適用することにより、電力損失を低減して高い充電効率を得ることができる。 According to the above configuration, since the charging voltage Vch for charging the secondary battery 4 is changed according to the battery voltage Vbatt of the secondary battery 4, the voltage difference between the battery voltage Vbatt and the charging voltage Vch of the secondary battery 4 is The power loss can be reduced. In addition, since the charging voltage is generated from the supplied power using a switching regulator having higher power conversion efficiency than the linear regulator, power loss due to the voltage difference between the input voltage Vin and the output voltage Vch of the charging voltage generation circuit 2 is reduced. be able to. Accordingly, it is possible to reduce power loss and obtain high charging efficiency. Moreover, also in the non-contact electric power feeding system 1 in which high-efficiency power use is required as in the present embodiment, by applying the charging device having the above configuration, it is possible to reduce power loss and obtain high charging efficiency. .
　ここで、充電装置の充電電圧生成回路２が出力する充電電圧Ｖｃｈと二次電池４の電池電圧Ｖｂａｔｔとの関係について説明する。図３は、図１に示す充電装置の充電電圧と二次電池の電池電圧との関係を示す図である。図３（ａ）は本実施形態のグラフを示し、図３（ｂ）は比較例として従来の一定電圧を印加して充電する構成におけるグラフを示している。 Here, the relationship between the charging voltage Vch output from the charging voltage generation circuit 2 of the charging device and the battery voltage Vbatt of the secondary battery 4 will be described. FIG. 3 is a diagram showing the relationship between the charging voltage of the charging device shown in FIG. 1 and the battery voltage of the secondary battery. FIG. 3A shows a graph of this embodiment, and FIG. 3B shows a graph in a configuration in which charging is performed by applying a constant voltage as a comparative example.
　図３（ｂ）に示すように、従来の充電装置においては、二次電池４の電池電圧Ｖｂａｔｔに関係なく、二次電池４を満充電まで充電し得る所定の一定電圧を充電電圧Ｖｃｈとして二次電池４に印加していた。図３（ｂ）においては、５．０Ｖの充電電圧を印加している様子が示されている。ところが、二次電池４の電池電圧Ｖｂａｔｔが低い場合（例えば３．０Ｖの場合）、充電電圧Ｖｃｈと電池電圧Ｖｂａｔｔとの差が大きくなり、電力損失が発生していた。図３（ｂ）に示す斜線部分の面積が電力損失の大きさを表している。図３（ｂ）に示すように、この電力損失は充電が進み電池電圧Ｖｂａｔｔが高くなってくると少なくなってくるが、充電期間全体の電力損失はかなり多くなる。 As shown in FIG. 3 (b), in the conventional charging device, a predetermined constant voltage that can charge the secondary battery 4 until full charge is used as the charging voltage Vch regardless of the battery voltage Vbatt of the secondary battery 4. The secondary battery 4 was applied. FIG. 3B shows a state in which a charging voltage of 5.0 V is applied. However, when the battery voltage Vbatt of the secondary battery 4 is low (for example, 3.0 V), the difference between the charging voltage Vch and the battery voltage Vbatt is large, resulting in power loss. The area of the shaded portion shown in FIG. 3B represents the magnitude of power loss. As shown in FIG. 3 (b), this power loss decreases as charging progresses and the battery voltage Vbatt increases, but the power loss over the entire charging period increases considerably.
　これに対し、図３（ａ）に示すように、本実施形態の充電装置によれば、二次電池４の電池電圧Ｖｂａｔｔに応じて二次電池４の充電電圧Ｖｃｈを追従させるように変化させるため、電池電圧Ｖｂａｔｔと充電電圧Ｖｃｈとの間の電圧差を小さくすることができ、電力損失（図３（ａ）の斜線部分の面積）を図３（ａ）のような従来の構成に比べて少なくすることができる。 On the other hand, as shown in FIG. 3A, according to the charging device of this embodiment, the charging voltage Vch of the secondary battery 4 is changed to follow the battery voltage Vbatt of the secondary battery 4. Therefore, the voltage difference between the battery voltage Vbatt and the charging voltage Vch can be reduced, and the power loss (area of the hatched portion in FIG. 3A) is compared with the conventional configuration as shown in FIG. Can be reduced.
　また、図３（ａ）に示すように、本実施形態における充電電圧生成回路２は、二次電池４の電池電圧Ｖｂａｔｔに数１００ｍＶ（図３（ａ）においては３００ｍＶ）のオフセット電圧Ｖｏを足し合わせた電圧を充電電圧として生成するよう構成されている。例えば、二次電池４の電池電圧Ｖｂａｔｔが３．０Ｖのときは、充電電圧生成回路２は充電電圧Ｖｃｈとして３．３Ｖ（Ｖｃｈ＝Ｖｂａｔｔ＋Ｖｏ）を出力し、二次電池４の電池電圧Ｖｂａｔｔが３．５Ｖのときは、充電電圧生成回路２は充電電圧Ｖｃｈとして３．８Ｖを出力し、二次電池４の電池電圧Ｖｂａｔｔが４．２Ｖのときは、充電電圧生成回路２は充電電圧Ｖｃｈとして４．５Ｖを出力する。 In addition, as shown in FIG. 3A, the charging voltage generation circuit 2 in the present embodiment adds an offset voltage Vo of several hundred mV (300 mV in FIG. 3A) to the battery voltage Vbatt of the secondary battery 4. The combined voltage is generated as a charging voltage. For example, when the battery voltage Vbatt of the secondary battery 4 is 3.0 V, the charging voltage generation circuit 2 outputs 3.3 V (Vch = Vbatt + Vo) as the charging voltage Vch, and the battery voltage Vbatt of the secondary battery 4 is 3 When the voltage is 0.5 V, the charging voltage generation circuit 2 outputs 3.8 V as the charging voltage Vch, and when the battery voltage Vbatt of the secondary battery 4 is 4.2 V, the charging voltage generation circuit 2 outputs 4 as the charging voltage Vch. .5V is output.
　このため、充電電圧生成回路２は、充電電圧Ｖｃｈに予め定められた電圧値を有するオフセット電圧Ｖｏを加算するオフセット加算器２２を有しており、比較器２３の－側入力端子に加算電圧（Ｖｃｈ＋Ｖｏ）が入力されるよう構成されている。これにより、ＤＣ－ＤＣコンバータ２１の出力電圧である充電電圧Ｖｃｈが第１基準電圧である二次電池４の電池電圧Ｖｂａｔｔよりオフセット電圧Ｖｏだけ高い電圧となるようにフィードバック制御される。 For this reason, the charging voltage generation circuit 2 has an offset adder 22 that adds an offset voltage Vo having a predetermined voltage value to the charging voltage Vch, and the added voltage ( Vch + Vo) is input. Thus, feedback control is performed so that the charging voltage Vch, which is the output voltage of the DC-DC converter 21, is higher than the battery voltage Vbatt of the secondary battery 4 that is the first reference voltage by the offset voltage Vo.
　このように、充電電圧Ｖｃｈが二次電池４の電池電圧Ｖｂａｔｔよりオフセット電圧Ｖｏだけ高い電圧となるため、充電制御回路３等に含まれる素子や温度変化による電圧のばらつきにより実際に二次電池４に印加される電圧が充電電圧生成回路２で生成された充電電圧Ｖｃｈより低下しても当該二次電池４に印加される電圧が二次電池４の電池電圧Ｖｂａｔｔより低くなることを防止することができる。従って、電圧低下による充電不良を防止することができる。 Thus, since the charging voltage Vch is higher than the battery voltage Vbatt of the secondary battery 4 by the offset voltage Vo, the secondary battery 4 is actually caused by variations in the elements included in the charging control circuit 3 and the voltage due to temperature changes. The voltage applied to the secondary battery 4 is prevented from becoming lower than the battery voltage Vbatt of the secondary battery 4 even if the voltage applied to the battery is lower than the charge voltage Vch generated by the charge voltage generation circuit 2. Can do. Therefore, it is possible to prevent a charging failure due to a voltage drop.
　なお、オフセット電圧Ｖｏは、充電制御回路３等に含まれる素子や使用温度環境により想定される電圧のばらつきを許容できる程度の電圧であれば特に限定されないが１００ｍＶ以上６００ｍＶ以下が好ましい範囲と想定される。 The offset voltage Vo is not particularly limited as long as it is a voltage that can tolerate variations in the voltage assumed depending on elements included in the charge control circuit 3 and the use temperature environment, but is assumed to be a preferable range of 100 mV to 600 mV. The
　また、図３（ａ）に示すように、本実施形態における充電電圧生成回路１は、二次電池４の電池電圧Ｖｂａｔｔが充電制御回路３の最低動作電圧ＶＬ（３．３Ｖ）以下である場合に、当該最低動作電圧ＶＬを充電電圧Ｖｃｈとして生成するよう構成されている。 In addition, as shown in FIG. 3A, the charging voltage generation circuit 1 in the present embodiment has a case where the battery voltage Vbatt of the secondary battery 4 is equal to or lower than the minimum operating voltage VL (3.3 V) of the charging control circuit 3. In addition, the minimum operating voltage VL is generated as the charging voltage Vch.
　具体的には図２に示すように、充電電圧生成回路２は、第２基準電圧である最低動作電圧ＶＬよりオフセット電圧Ｖｏだけ低い電圧（ＶＬ－Ｖｏ：３．０Ｖ）を生成する電圧源２６と、第１基準電圧である二次電池４の電池電圧Ｖｂａｔｔと電圧源２６により生成される第２基準電圧とが入力され、第１基準電圧及び第２基準電圧のうち何れか高い方の電圧を比較器２３の基準電圧Ｖｒｅｆとして出力する最大値選択回路２４とを有している。 Specifically, as shown in FIG. 2, the charging voltage generation circuit 2 generates a voltage source 26 that generates a voltage (VL−Vo: 3.0V) that is lower than the lowest operating voltage VL that is the second reference voltage by the offset voltage Vo. And the battery voltage Vbatt of the secondary battery 4 that is the first reference voltage and the second reference voltage generated by the voltage source 26, and the higher one of the first reference voltage and the second reference voltage. Is output as the reference voltage Vref of the comparator 23.
　これにより、二次電池４の電池電圧Ｖｂａｔｔが電圧源２６により生成される第２基準電圧（ＶＬ－Ｖｏ）より高い電圧であれば、比較器２３において、加算電圧（Ｖｃｈ＋Ｖｏ）は電池電圧Ｖｂａｔｔと比較され、二次電池４の電池電圧Ｖｂａｔｔが電圧源２６により生成される第２基準電圧（ＶＬ－Ｖｏ）以下の電圧であれば、比較器２３において、加算電圧（Ｖｃｈ＋Ｖｏ）は第２基準電圧（ＶＬ－Ｖｏ）と比較される。従って、二次電池４の電池電圧Ｖｂａｔｔが第２基準電圧（ＶＬ－Ｖｏ）より高い電圧であれば、ＤＣ－ＤＣコンバータ２１は、充電電圧Ｖｃｈが電池電圧Ｖｂａｔｔよりオフセット電圧Ｖｏだけ高い電圧（図３の例ではＶｂａｔｔ＋０．３Ｖ）となるように制御され、二次電池４の電池電圧Ｖｂａｔｔが第２基準電圧（ＶＬ－Ｖｏ）以下の電圧であれば、ＤＣ－ＤＣコンバータ２１は、充電電圧Ｖｃｈが充電制御回路３の最低動作電圧ＶＬ（図３の例では３．３Ｖ）となるように制御される。 Thus, if the battery voltage Vbatt of the secondary battery 4 is higher than the second reference voltage (VL−Vo) generated by the voltage source 26, the comparator 23 adds the added voltage (Vch + Vo) to the battery voltage Vbatt. If the battery voltage Vbatt of the secondary battery 4 is a voltage equal to or lower than the second reference voltage (VL−Vo) generated by the voltage source 26, the comparator 23 adds the added voltage (Vch + Vo) to the second reference voltage. It is compared with (VL-Vo). Therefore, if the battery voltage Vbatt of the secondary battery 4 is higher than the second reference voltage (VL-Vo), the DC-DC converter 21 is such that the charging voltage Vch is higher than the battery voltage Vbatt by the offset voltage Vo (see FIG. In the example of FIG. 3, if the battery voltage Vbatt of the secondary battery 4 is a voltage equal to or lower than the second reference voltage (VL-Vo), the DC-DC converter 21 is charged with the charging voltage Vch. Is controlled to be the minimum operating voltage VL of the charging control circuit 3 (3.3 V in the example of FIG. 3).
　以上より、二次電池４の電池電圧Ｖｂａｔｔが充電制御回路３が動作しない電圧である場合には、充電電圧Ｖｃｈを充電制御回路３の最低動作電圧ＶＬとすることにより、充電制御回路３の最低限の動作を確保しつつ電力損失を極力抑えることができる。図３（ｂ）に示すような従来の構成では、充電電圧Ｖｃｈが一定（５．０Ｖ）であるため、二次電池４の電池電圧Ｖｂａｔｔと充電制御回路３の最低動作電圧ＶＬとは何らの関係性をも有しておらず、充電制御回路３を動作させるために無駄な電圧が印加されていた。これに対し、図３（ａ）に示すような本実施形態の構成では、充電時に充電制御回路３の動作を考慮しながら最低限の電圧を印加することにより電力損失を少なくすることができる。 As described above, when the battery voltage Vbatt of the secondary battery 4 is a voltage at which the charging control circuit 3 does not operate, the charging voltage Vch is set to the minimum operating voltage VL of the charging control circuit 3, thereby The power loss can be suppressed as much as possible while ensuring the limit operation. In the conventional configuration as shown in FIG. 3B, since the charging voltage Vch is constant (5.0 V), what is the battery voltage Vbatt of the secondary battery 4 and the minimum operating voltage VL of the charging control circuit 3? There is no relationship, and a useless voltage is applied to operate the charge control circuit 3. On the other hand, in the configuration of the present embodiment as shown in FIG. 3A, power loss can be reduced by applying a minimum voltage while considering the operation of the charge control circuit 3 during charging.
　最大値選択回路２４の構成は特に限定されないが、例えば以下のように例示できる。図４は、図２に示される最大値選択回路を示す回路図である。図４に示すように、本実施形態において、最大値選択回路２４は、比較器２３に第１基準電圧（電池電圧Ｖｂａｔｔ）又は第２基準電圧（ＶＬ－Ｖｏ）のいずれか一方を選択的に接続するスイッチング回路２４１と、第１基準電圧（電池電圧Ｖｂａｔｔ）と第２基準電圧（ＶＬ－Ｖｏ）とを比較する比較器２４２とを有している。スイッチング回路２４１は、比較器２４２において比較された第１及び第２基準電圧のうち電圧が高い方を比較器２３と接続するように構成されている。 The configuration of the maximum value selection circuit 24 is not particularly limited, but can be exemplified as follows, for example. FIG. 4 is a circuit diagram showing the maximum value selection circuit shown in FIG. As shown in FIG. 4, in the present embodiment, the maximum value selection circuit 24 selectively selects either the first reference voltage (battery voltage Vbatt) or the second reference voltage (VL-Vo) for the comparator 23. A switching circuit 241 to be connected and a comparator 242 for comparing the first reference voltage (battery voltage Vbatt) and the second reference voltage (VL-Vo). The switching circuit 241 is configured to connect the higher one of the first and second reference voltages compared in the comparator 242 to the comparator 23.
　なお、本実施形態において電圧源２６が第２基準電圧（ＶＬ－Ｖｏ）を有するものとして説明したが、例えば電圧源２６としてバンドギャップ電圧（約１．２Ｖ）のような電圧源を第２基準電圧（ＶＬ－Ｖｏ）まで昇圧又は降圧して制御対象である加算電圧（Ｖｃｈ＋Ｖｏ）と比較してもよい。また、この場合、制御対象である加算電圧（Ｖｃｈ＋Ｖｏ）を対応する電圧まで降圧又は昇圧した上で電圧源２６により生成される第２基準電圧（バンドギャップ電圧）と比較してもよい。 In the present embodiment, the voltage source 26 has been described as having the second reference voltage (VL-Vo). For example, a voltage source such as a band gap voltage (about 1.2 V) is used as the second reference voltage. The voltage may be increased or decreased to the voltage (VL−Vo) and compared with the addition voltage (Vch + Vo) to be controlled. In this case, the addition voltage (Vch + Vo) to be controlled may be stepped down or boosted to a corresponding voltage and then compared with the second reference voltage (band gap voltage) generated by the voltage source 26.
　＜第１実施形態の変形例＞
　続いて、本発明の第１実施形態の充電装置における充電電圧生成回路の他の例について説明する。図５は、本発明の第１実施形態の変形例における充電装置の充電電圧生成回路の概略構成を示す回路図である。本変形例において第１実施形態と同様の構成については同じ符号を付し、説明を省略する。 <Modification of First Embodiment>
Next, another example of the charging voltage generation circuit in the charging device according to the first embodiment of the present invention will be described. FIG. 5 is a circuit diagram showing a schematic configuration of a charging voltage generation circuit of the charging device according to a modification of the first embodiment of the present invention. In this modification, the same reference numerals are given to the same components as those in the first embodiment, and the description thereof is omitted.
　図５に示されるように、本変形例における充電装置（２次側制御ユニット７Ｂ）が第１実施形態と異なる点は、充電電圧生成回路３２において、オフセット加算器２２が二次電池４の電池電圧Ｖｂａｔｔにオフセット電圧Ｖｏを加算した加算電圧（Ｖｂａｔｔ＋Ｖｏ）を出力するよう構成されていること、及び、比較器２３がＤＣ－ＤＣコンバータ２１の出力電圧（すなわち充電電圧生成回路２の出力電圧である充電電圧Ｖｃｈ）を上記加算電圧（Ｖｂａｔｔ＋Ｖｏ）と比較することである。すなわち、第１基準電圧が上記加算電圧（Ｖｂａｔｔ＋Ｖｏ）となる。制御回路２５は、比較器２３の出力電圧に応じて、充電電圧Ｖｃｈが第１基準電圧である加算電圧（Ｖｂａｔｔ＋Ｖｏ）となるようにＤＣ－ＤＣコンバータ２１の出力電圧（充電電圧Ｖｃｈ）を調整する。 As shown in FIG. 5, the charging device (secondary control unit 7B) in the present modification is different from the first embodiment in that the offset adder 22 is a battery of the secondary battery 4 in the charging voltage generation circuit 32. It is configured to output an addition voltage (Vbatt + Vo) obtained by adding the offset voltage Vo to the voltage Vbatt, and the comparator 23 is an output voltage of the DC-DC converter 21 (that is, an output voltage of the charging voltage generation circuit 2). The charging voltage Vch) is compared with the added voltage (Vbatt + Vo). That is, the first reference voltage becomes the above-mentioned addition voltage (Vbatt + Vo). The control circuit 25 adjusts the output voltage (charge voltage Vch) of the DC-DC converter 21 according to the output voltage of the comparator 23 so that the charge voltage Vch becomes the addition voltage (Vbatt + Vo) which is the first reference voltage. .
　このような構成においても、第１実施形態と同様に、ＤＣ－ＤＣコンバータ２１の出力電圧である充電電圧Ｖｃｈが第１基準電圧である二次電池４の電池電圧Ｖｂａｔｔとオフセット電圧Ｖｏとの加算電圧（Ｖｂａｔｔ＋Ｖｏ）となるようにフィードバック制御される。 Also in such a configuration, as in the first embodiment, the charging voltage Vch, which is the output voltage of the DC-DC converter 21, is the addition of the battery voltage Vbatt and the offset voltage Vo of the secondary battery 4 that is the first reference voltage. Feedback control is performed so that the voltage becomes (Vbatt + Vo).
　このように、本変形例においても充電電圧Ｖｃｈが二次電池４の電池電圧Ｖｂａｔｔよりオフセット電圧Ｖｏだけ高い電圧となるため、充電制御回路３等に含まれる素子や温度変化による電圧のばらつきにより実際に二次電池４に印加される電圧が充電電圧生成回路２で生成された充電電圧Ｖｃｈより低下しても当該二次電池４に印加される電圧が二次電池４の電池電圧Ｖｂａｔｔより低くなることを防止することができる。従って、電圧低下による充電不良を防止することができる。 As described above, also in this modification, the charging voltage Vch is higher than the battery voltage Vbatt of the secondary battery 4 by the offset voltage Vo. Therefore, the charging voltage Vch is actually caused by variations in the elements included in the charging control circuit 3 and the voltage due to temperature changes. Even if the voltage applied to the secondary battery 4 drops below the charging voltage Vch generated by the charging voltage generation circuit 2, the voltage applied to the secondary battery 4 becomes lower than the battery voltage Vbatt of the secondary battery 4. This can be prevented. Therefore, it is possible to prevent a charging failure due to a voltage drop.
　さらに、充電電圧生成回路３２は、第２基準電圧である最低動作電圧ＶＬ（３．３Ｖ）を生成する電圧源３４と、第１基準電圧である加算電圧（Ｖｂａｔｔ＋Ｖｏ）と電圧源３４により生成される第２基準電圧とが入力され、第１基準電圧及び第２基準電圧のうち何れか高い方の電圧を比較器２３の基準電圧Ｖｒｅｆとして出力する最大値選択回路３３とを有している。 Further, the charging voltage generation circuit 32 is generated by the voltage source 34 that generates the lowest operating voltage VL (3.3 V) that is the second reference voltage, and the addition voltage (Vbatt + Vo) that is the first reference voltage and the voltage source 34. And a maximum value selection circuit 33 that outputs the higher one of the first reference voltage and the second reference voltage as the reference voltage Vref of the comparator 23.
　これにより、二次電池４の電池電圧Ｖｂａｔｔとオフセット電圧Ｖｏとの加算電圧（Ｖｂａｔｔ＋Ｖｏ）が電圧源３４により生成される充電制御回路３の最低動作電圧ＶＬより高い電圧であれば、比較器２３において、充電電圧Ｖｃｈは加算電圧（Ｖｂａｔｔ＋Ｖｏと比較され、加算電圧（Ｖｂａｔｔ＋Ｖｏ）が電圧源３４により生成される充電制御回路３の最低動作電圧ＶＬ以下の電圧であれば、比較器２３において、充電電圧Ｖｃｈは最低動作電圧ＶＬと比較される。従って、加算電圧（Ｖｂａｔｔ＋Ｖｏ）が最低動作電圧ＶＬより高い電圧であれば、ＤＣ－ＤＣコンバータ２１は、充電電圧Ｖｃｈが電池電圧Ｖｂａｔｔよりオフセット電圧Ｖｏだけ高い電圧（図３の例ではＶｂａｔｔ＋０．３Ｖ）となるように制御され、加算電圧（Ｖｂａｔｔ＋Ｖｏ）が最低動作電圧ＶＬ以下の電圧であれば、ＤＣ－ＤＣコンバータ２１は、充電電圧Ｖｃｈが充電制御回路３の最低動作電圧ＶＬ（図３の例では３．３Ｖ）となるように制御される。 Thus, if the voltage (Vbatt + Vo) of the battery voltage Vbatt and the offset voltage Vo of the secondary battery 4 is higher than the minimum operating voltage VL of the charge control circuit 3 generated by the voltage source 34, the comparator 23 The charging voltage Vch is compared with the addition voltage (Vbatt + Vo), and if the addition voltage (Vbatt + Vo) is equal to or lower than the minimum operating voltage VL of the charging control circuit 3 generated by the voltage source 34, the comparator 23 charges the charging voltage Vch. Therefore, if the added voltage (Vbatt + Vo) is higher than the lowest operating voltage VL, the DC-DC converter 21 has a charging voltage Vch higher than the battery voltage Vbatt by the offset voltage Vo. (Vbatt + 0.3V in the example of FIG. 3) and the added voltage ( If batt + Vo) is equal to or lower than the minimum operating voltage VL, the DC-DC converter 21 is controlled so that the charging voltage Vch becomes the minimum operating voltage VL of the charging control circuit 3 (3.3 V in the example of FIG. 3). The
　このように、本変形例の構成においても第１実施形態と同様に、二次電池４の電池電圧Ｖｂａｔｔが充電制御回路３が動作しない電圧である場合には、充電電圧Ｖｃｈを充電制御回路３の最低動作電圧ＶＬとすることにより、充電制御回路３の最低限の動作を確保しつつ電力損失を極力抑えることができる。 As described above, also in the configuration of this modification, as in the first embodiment, when the battery voltage Vbatt of the secondary battery 4 is a voltage at which the charge control circuit 3 does not operate, the charge voltage Vch is used as the charge control circuit 3. By setting the minimum operating voltage VL, the power loss can be suppressed as much as possible while ensuring the minimum operation of the charging control circuit 3.
　ここでも、最大値選択回路３３の構成は特に限定されないが、例えば以下のように例示できる。図６は、図５に示される最大値選択回路を示す回路図である。図６に示すように、本変形例において、最大値選択回路３３は、比較器２３に第１基準電圧（Ｖｂａｔｔ＋Ｖｏ）又は第２基準電圧（ＶＬ）のいずれか一方を選択的に接続するスイッチング回路３３１と、二次電池４の電池電圧Ｖｂａｔｔと最低動作電圧ＶＬとを比較する比較器３３２とを有している。スイッチング回路３３１は、比較器３３２において比較された電池電圧Ｖｂａｔｔ及び最低動作電圧ＶＬのうち電池電圧Ｖｂａｔｔの方が高ければ第１基準電圧（Ｖｂａｔｔ＋Ｖｏ）を比較器２３と接続し、最低動作電圧ＶＬの方が高ければ第２基準電圧ＶＬ（電圧源３４）を比較器２３と接続するように構成されている。 Here, the configuration of the maximum value selection circuit 33 is not particularly limited, but can be exemplified as follows, for example. FIG. 6 is a circuit diagram showing the maximum value selection circuit shown in FIG. As shown in FIG. 6, in this modification, the maximum value selection circuit 33 is a switching circuit that selectively connects either the first reference voltage (Vbatt + Vo) or the second reference voltage (VL) to the comparator 23. 331 and a comparator 332 that compares the battery voltage Vbatt of the secondary battery 4 and the minimum operating voltage VL. The switching circuit 331 connects the first reference voltage (Vbatt + Vo) to the comparator 23 if the battery voltage Vbatt is higher than the battery voltage Vbatt and the minimum operating voltage VL compared in the comparator 332, and the minimum operating voltage VL is set. If it is higher, the second reference voltage VL (voltage source 34) is connected to the comparator 23.
　＜第２実施形態＞
　次に、本発明の第２実施形態について説明する。図７は、本発明の第２実施形態における充電装置が適用された非接触給電システムの概略構成を示す回路図である。なお、図７においては非接触給電システムの送電部は第１実施形態と同様であるため、図示を省略し受電部のみ示している。本実施形態において第１実施形態と同様の構成については同じ符号を付し、説明を省略する。 Second Embodiment
Next, a second embodiment of the present invention will be described. FIG. 7 is a circuit diagram illustrating a schematic configuration of a non-contact power feeding system to which the charging device according to the second embodiment of the present invention is applied. In FIG. 7, the power transmission unit of the non-contact power feeding system is the same as that of the first embodiment, and therefore, illustration is omitted and only the power reception unit is shown. In the present embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.
　図７に示されるように、本実施形態における非接触給電システム４０が第１実施形態と異なる点は、充電装置（２次側制御ユニット７Ｃ）が、充電電圧生成回路４２と二次電池４との間に設けられた逆流防止回路４３を備えていることである。具体的には、逆流防止回路４３は、充電電圧生成回路２から二次電池４へ向かう方向を順方向とする整流素子４３２と、整流素子４３２と並列に接続されたスイッチング素子４３１と、二次電池４の充電開始後にスイッチング素子４３１を導通状態にし、二次電池４の充電後は逆流防止回路４３を非導通状態にする逆流防止制御回路４４とを有している。さらに、充電装置は、二次電池４の充電中に逆流防止回路４３を導通状態にし、二次電池４の充電後は逆流防止回路４３を非導通状態にする逆流防止制御回路４４とをさらに有している。 As shown in FIG. 7, the non-contact power feeding system 40 in the present embodiment is different from the first embodiment in that the charging device (secondary control unit 7 </ b> C) includes the charging voltage generation circuit 42, the secondary battery 4, and the like. Is provided with a backflow prevention circuit 43 provided therebetween. Specifically, the backflow prevention circuit 43 includes a rectifying element 432 having a forward direction from the charging voltage generation circuit 2 toward the secondary battery 4, a switching element 431 connected in parallel with the rectifying element 432, a secondary There is a backflow prevention control circuit 44 that turns on the switching element 431 after the battery 4 starts charging and turns off the backflow prevention circuit 43 after the secondary battery 4 is charged. Further, the charging device further includes a backflow prevention control circuit 44 that turns on the backflow prevention circuit 43 during charging of the secondary battery 4 and turns off the backflow prevention circuit 43 after charging of the secondary battery 4. is doing.
　本実施形態におけるスイッチング素子４３１は、充電電圧生成回路４２の出力側と充電制御回路３の入力側との間に２つの主端子（ドレイン端子及びソース端子）が接続されたＭＯＳトランジスタ(transistor)により構成される（以下、ＭＯＳトランジスタ４３１と表記する）。整流素子４３２は、ＭＯＳトランジスタ４３１の主端子間に接続され、充電電圧生成回路４２から充電制御回路３へ向かう方向を順方向とするダイオードにより構成される。また、逆流防止回路４３は、ＭＯＳトランジスタ４３１の充電制御回路３の入力側の主端子（ソース端子）と制御端子（ゲート端子）との間に接続された抵抗４３３を有している。 The switching element 431 in the present embodiment is a MOS transistor (transistor) in which two main terminals (drain terminal and source terminal) are connected between the output side of the charging voltage generation circuit 42 and the input side of the charging control circuit 3. (Hereinafter referred to as MOS transistor 431). The rectifying element 432 is connected between the main terminals of the MOS transistor 431 and is configured by a diode having a forward direction from the charging voltage generation circuit 42 toward the charging control circuit 3. Further, the backflow prevention circuit 43 has a resistor 433 connected between the main terminal (source terminal) on the input side of the charge control circuit 3 of the MOS transistor 431 and the control terminal (gate terminal).
　逆流防止制御回路４４は、出力側がＭＯＳトランジスタ４３１の制御端子（ゲート端子）に接続されており、逆流防止制御回路４４から出力される制御電圧Ｖｃｏｎｔに応じてＭＯＳトランジスタ４３１がＯＮ又はＯＦＦされ、逆流防止回路４３の動作が制御される。逆流防止制御回路４４は論理回路により構成されており、充電電圧生成回路４２の充電時又は非充電時に応じて出力される充電状況電圧Ｖｅｎに応じて動作する。なお、図７においてはＭＯＳトランジスタ４３１はＰ型のＭＯＳＦＥＴを用いた例を示しているがＮ型であってもよいし、他の種類のＦＥＴであってもよい。 The output side of the backflow prevention control circuit 44 is connected to the control terminal (gate terminal) of the MOS transistor 431, and the MOS transistor 431 is turned on or off in accordance with the control voltage Vcont output from the backflow prevention control circuit 44. The operation of the prevention circuit 43 is controlled. The backflow prevention control circuit 44 is configured by a logic circuit, and operates according to the charging status voltage Ven that is output according to the charging voltage generation circuit 42 being charged or not charged. Although FIG. 7 shows an example in which the MOS transistor 431 uses a P-type MOSFET, it may be an N-type or another type of FET.
　本実施形態の逆流防止回路４３の具体的な動作について説明する。図８は、図７に示される充電装置の各部の電圧の時間変化を示すグラフである。図８に示されるように、非接触給電装置１０の受電部９に電力が供給されると、充電電圧生成回路４２への入力電圧Ｖｉｎが上昇する。入力電圧Ｖｉｎが所定の電圧（図８においては４．０Ｖ）に達すると、充電電圧生成回路４２は、二次電池４への充電を開始するべく１次側制御ユニット６から供給電力とともに伝送されたデータの認証処理等の制御シーケンス(sequence)を実行する。この間、充電電圧生成回路４２は充電を開始することなく待機する（図８のＶｅｎにおける待機時間参照）。 The specific operation of the backflow prevention circuit 43 of this embodiment will be described. FIG. 8 is a graph showing the time change of the voltage of each part of the charging apparatus shown in FIG. As shown in FIG. 8, when power is supplied to the power receiving unit 9 of the contactless power supply device 10, the input voltage Vin to the charging voltage generation circuit 42 increases. When the input voltage Vin reaches a predetermined voltage (4.0 V in FIG. 8), the charging voltage generation circuit 42 is transmitted from the primary side control unit 6 together with the supplied power to start charging the secondary battery 4. A control sequence such as data authentication processing is executed. During this time, the charging voltage generation circuit 42 waits without starting charging (see the waiting time at Ven in FIG. 8).
　所定の制御シーケンスの終了後（又は所定の待機時間経過後）、充電電圧生成回路４２は、ＤＣ－ＤＣコンバータ２１の出力電圧Ｖｏｕｔを上昇させ、二次電池４への充電を開始する。このとき、充電状況電圧Ｖｅｎは、第１の電圧（Ｌレベルの電圧）から第１の電圧とは異なる第２の電圧（Ｌレベルより高いＨレベルの電圧）へと状態遷移する。これにより、充電電圧生成回路４２から逆流防止制御回路４４に充電開始が伝えられる。充電開始直後はＭＯＳトランジスタ４３１はＯＦＦのままであるため、充電電圧生成回路４２から出力された電力は、整流素子４３２を通じて充電制御回路３へ伝送される。ＭＯＳトランジスタ４３１を導通状態とした際に充電電圧生成回路２の出力電圧Ｖｏｕｔが二次電池４の電池電圧Ｖｂａｔｔより低い状態であった場合、二次電池４から充電電圧生成回路４２へ逆流電流が流れるおそれがある。これを防止するために、ＭＯＳトランジスタ４３１を非導通状態とすることにより逆流電流を防止しつつ整流素子４３２を通じて充電を開始することができる。このとき、整流素子４３２の抵抗分により充電電圧Ｖｃｈは充電電圧生成回路４２の出力電圧Ｖｏｕｔより抵抗分だけ低い電圧までしか達しない。 After completion of the predetermined control sequence (or after the elapse of a predetermined standby time), the charging voltage generation circuit 42 increases the output voltage Vout of the DC-DC converter 21 and starts charging the secondary battery 4. At this time, the state of charge state voltage Ven changes from the first voltage (L level voltage) to a second voltage (H level voltage higher than L level) different from the first voltage. As a result, the charging voltage generation circuit 42 notifies the backflow prevention control circuit 44 of the start of charging. Since the MOS transistor 431 remains off immediately after the start of charging, the power output from the charging voltage generation circuit 42 is transmitted to the charging control circuit 3 through the rectifying element 432. If the output voltage Vout of the charging voltage generation circuit 2 is lower than the battery voltage Vbatt of the secondary battery 4 when the MOS transistor 431 is turned on, a backflow current flows from the secondary battery 4 to the charging voltage generation circuit 42. May flow. In order to prevent this, charging can be started through the rectifying element 432 while preventing a reverse current by setting the MOS transistor 431 in a non-conductive state. At this time, the charging voltage Vch reaches only a voltage lower than the output voltage Vout of the charging voltage generation circuit 42 by the resistance due to the resistance of the rectifying element 432.
　充電電圧生成回路４２から逆流防止制御回路４４に充電開始が伝えられた後、所定のタイミングで逆流防止制御回路４４は、制御電圧Ｖｃｏｎｔを第１の電圧（Ｌレベルの電圧）から第１の電圧Ｌとは異なる第２の電圧（Ｌレベルより高いＨレベルの電圧）へと状態遷移させる。所定のタイミングは、例えば逆流防止制御回路４４の制御シーケンスが終了した段階又は所定の待機時間経過後（例えば、制御シーケンスが終了する、及び／又は充電電圧生成回路４２の出力電圧Ｖｏｕｔが立ち上がるのに十分な時間経過後）である。 After the charging start is transmitted from the charging voltage generation circuit 42 to the backflow prevention control circuit 44, the backflow prevention control circuit 44 changes the control voltage Vcont from the first voltage (L level voltage) to the first voltage at a predetermined timing. State transition is made to a second voltage different from L (voltage of H level higher than L level). The predetermined timing is, for example, at the stage when the control sequence of the backflow prevention control circuit 44 is completed or after a predetermined standby time has elapsed (for example, when the control sequence ends and / or the output voltage Vout of the charging voltage generation circuit 42 rises). After sufficient time).
　制御電圧Ｖｃｏｎｔが第２の電圧Ｈに状態遷移することにより、ＭＯＳトランジスタ４３１はＯＮされる。これにより、ＭＯＳトランジスタ４３１の主端子間は導通状態となり、ＭＯＳトランジスタ４３１の内部抵抗は整流素子４３２の抵抗分に比較して十分小さいため、充電電圧生成回路４２の出力電圧Ｖｏｕｔ及び充電電圧Ｖｃｈは略同じ電圧となる。なお、充電中は、充電電圧生成回路４２のＤＣ－ＤＣコンバータ２１から二次電池４の電池電圧Ｖｂａｔｔより高い電圧が印加されているので、充電電圧生成回路４２へ二次電池４から逆流電流が流れることはない。 When the control voltage Vcont transitions to the second voltage H, the MOS transistor 431 is turned on. As a result, the main terminals of the MOS transistor 431 become conductive, and the internal resistance of the MOS transistor 431 is sufficiently smaller than the resistance of the rectifying element 432, so that the output voltage Vout and the charging voltage Vch of the charging voltage generation circuit 42 are The voltage is almost the same. During charging, since a voltage higher than the battery voltage Vbatt of the secondary battery 4 is applied from the DC-DC converter 21 of the charge voltage generation circuit 42, a reverse current from the secondary battery 4 is applied to the charge voltage generation circuit 42. There is no flow.
　充電終了後、充電電圧生成回路４２の入力電圧Ｖｉｎが立ち下がり、所定の電圧以下（図８においては３．５Ｖ）となると、充電電圧生成回路４２は、充電状況電圧Ｖｅｎを第２の電圧Ｈから第１の電圧Ｌへと状態遷移させるとともに、電圧出力を停止する（Ｖｏｕｔ＝Ｖｃｈ＝０）。充電状況電圧Ｖｅｎの第１の電圧Ｌへの状態遷移に応じて逆流防止制御回路４４は、制御電圧Ｖｃｏｎｔを第２の電圧Ｈから第１の電圧Ｌへと状態遷移させ、ＭＯＳトランジスタ４３１をＯＦＦする。これにより、ＭＯＳトランジスタ４３１の主端子間は非導通状態となるとともに、抵抗４３３により接続されている充電制御回路３側の主端子（ソース端子）と制御端子（ゲート端子）とが同じ電圧となるため、充電終了後において、二次電池４の電池電圧Ｖｂａｔｔが充電電圧生成回路４２の電圧より高くなっても、二次電池４から充電電圧生成回路４２のＤＣ－ＤＣコンバータ２１へ逆流電流が流れることを防止することができる。 After the end of charging, when the input voltage Vin of the charging voltage generating circuit 42 falls and becomes equal to or lower than a predetermined voltage (3.5 V in FIG. 8), the charging voltage generating circuit 42 converts the charging status voltage Ven to the second voltage H State transition from to the first voltage L, and the voltage output is stopped (Vout = Vch = 0). In response to the state transition of the charging state voltage Ven to the first voltage L, the backflow prevention control circuit 44 changes the state of the control voltage Vcont from the second voltage H to the first voltage L, and turns off the MOS transistor 431. To do. As a result, the main terminals of the MOS transistor 431 become non-conductive, and the main terminal (source terminal) and the control terminal (gate terminal) on the charge control circuit 3 side connected by the resistor 433 have the same voltage. Therefore, a reverse current flows from the secondary battery 4 to the DC-DC converter 21 of the charging voltage generation circuit 42 even when the battery voltage Vbatt of the secondary battery 4 becomes higher than the voltage of the charging voltage generation circuit 42 after the end of charging. This can be prevented.
　このように、二次電池４の充電開始後は、充電電圧生成回路２の出力電圧Ｖｏｕｔが高くなり充電電圧生成回路２に逆流電流が流れることはないため、スイッチング素子であるＭＯＳトランジスタ４３１を導通状態にすることにより二次電池４への電力供給を促進させるように動作する一方、充電終了後、二次電池４の電池電圧Ｖｂａｔｔより充電電圧生成回路２の出力電圧Ｖｏｕｔが低くなると充電電圧生成回路２に逆流電流が流れるおそれがあるため、ＭＯＳトランジスタ４３１を非導通状態にすることにより充電電圧生成回路２へ逆流電流が流れることを有効に防止することができる。 As described above, after charging of the secondary battery 4 is started, the output voltage Vout of the charging voltage generation circuit 2 becomes high and no reverse current flows through the charging voltage generation circuit 2, so that the MOS transistor 431 serving as a switching element is made conductive. While operating to promote power supply to the secondary battery 4 by setting the state, when the output voltage Vout of the charging voltage generation circuit 2 becomes lower than the battery voltage Vbatt of the secondary battery 4 after the end of charging, the charging voltage is generated. Since a backflow current may flow through the circuit 2, it is possible to effectively prevent a backflow current from flowing into the charging voltage generation circuit 2 by making the MOS transistor 431 non-conductive.
　なお、本実施形態においては、逆流防止回路４３がスイッチング素子であるＭＯＳトランジスタ４３１と整流素子４３２とを有する構成について説明したが、整流素子４３２のない構成（逆流防止回路４３がスイッチング素子を有し、充電装置がスイッチング素子のＯＮ又はＯＦＦを制御する逆流防止制御回路４４を備えている構成）としてもよいし、単に整流素子４３２のみを有する構成（スイッチング素子及び逆流防止制御回路４４のない構成）としてもよい。 In the present embodiment, the configuration in which the backflow prevention circuit 43 includes the MOS transistor 431 and the rectifying element 432 as switching elements has been described. However, the configuration without the rectifying element 432 (the backflow prevention circuit 43 has a switching element). The charging device may be configured to include a backflow prevention control circuit 44 that controls ON or OFF of the switching element), or may include only the rectifying element 432 (configuration that does not include the switching element and the backflow prevention control circuit 44). It is good.
　＜第３実施形態＞
　続いて、本発明の第３実施形態について説明する。本実施形態は、第１実施形態と同様の充電装置を他のシステムに適用した例を示すものである。図９は、本発明の第３実施形態における充電装置が適用された充電システムの概略構成を示す回路図である。本実施形態において第１実施形態と同様の構成については同じ符号を付し、説明を省略する。 <Third Embodiment>
Subsequently, a third embodiment of the present invention will be described. The present embodiment shows an example in which the same charging device as that of the first embodiment is applied to another system. FIG. 9 is a circuit diagram illustrating a schematic configuration of a charging system to which the charging device according to the third embodiment of the present invention is applied. In the present embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.
　図９に示されるように、本実施形態における充電システム５０が第１実施形態と異なる点は、充電装置７Ｄが、交流電源１１に接続され、充電装置７Ｄの充電電圧生成回路２への供給電力が交流電源１１から出力される電力であることである。具体的には、充電システム５０の充電装置７Ｄは、交流電源１１の交流電力を直流電力に変換するＡＣ－ＤＣ変換器５１を有している。ＡＣ－ＤＣ変換器５１は、直流電力に基づく直流電圧（Ｖｉｎ）を出力している。この直流電圧が充電電圧生成回路２の入力電圧Ｖｉｎとなる。このように、本発明の充電装置は、供給される電力に拘わらず、二次電池４を充電するための充電装置として広く適用できる。なお、本実施形態においては交流電源１１が接続された構成について説明したが、直流電源を接続することとしてもよい。この場合、充電装置内にＡＣ－ＤＣ変換器５１を設ける必要がなくなる。 As shown in FIG. 9, the charging system 50 in the present embodiment is different from the first embodiment in that the charging device 7D is connected to the AC power supply 11 and the power supplied to the charging voltage generation circuit 2 of the charging device 7D. Is the power output from the AC power supply 11. Specifically, the charging device 7D of the charging system 50 includes an AC-DC converter 51 that converts AC power of the AC power supply 11 into DC power. The AC-DC converter 51 outputs a DC voltage (Vin) based on DC power. This DC voltage becomes the input voltage Vin of the charging voltage generation circuit 2. Thus, the charging device of the present invention can be widely applied as a charging device for charging the secondary battery 4 regardless of the supplied power. In the present embodiment, the configuration in which the AC power supply 11 is connected has been described. However, a DC power supply may be connected. In this case, it is not necessary to provide the AC-DC converter 51 in the charging device.
　以上、本発明の実施形態について説明したが、本発明は上記実施形態に限定されるものではなく、その趣旨を逸脱しない範囲内で種々の改良、変更、修正が可能である。例えば、複数の上記実施形態及び変形例における各構成要素を任意に組み合わせることとしてもよい。 As mentioned above, although embodiment of this invention was described, this invention is not limited to the said embodiment, A various improvement, change, and correction are possible within the range which does not deviate from the meaning. For example, it is good also as combining each component in several said embodiment and modification arbitrarily.
　上記説明から、当業者にとっては、本発明の多くの改良や他の実施形態が明らかである。従って、上記説明は、例示としてのみ解釈されるべきであり、本発明を実行する最良の態様を当業者に教示する目的で提供されたものである。本発明の精神を逸脱することなく、その構造及び／又は機能の詳細を実質的に変更できる。 From the above description, many modifications and other embodiments of the present invention are apparent to persons skilled in the art. Accordingly, the foregoing description should be construed as illustrative only and is provided for the purpose of teaching those skilled in the art the best mode of carrying out the invention. The details of the structure and / or function may be substantially changed without departing from the spirit of the invention.
　本発明の充電装置は、電力損失を低減して高い充電効率を得るために有用である。特に、高効率な電力利用が求められる非接触給電システムにおいて、電力損失を低減して高い充電効率を得るために有用である。 The charging device of the present invention is useful for reducing power loss and obtaining high charging efficiency. In particular, in a non-contact power supply system that requires highly efficient power use, it is useful for reducing power loss and obtaining high charging efficiency.
１，４０　非接触給電システム
２，３２，４２　充電電圧生成回路
３　充電制御回路
４　二次電池
５　送電制御装置
６　１次側制御ユニット
７，７Ｂ，７Ｃ，７Ｄ　２次側制御ユニット（充電装置）
８　送電部
９　受電部
１０　非接触給電装置
１１　交流電源
２１　ＤＣ－ＤＣコンバータ
２２　オフセット加算器
２３　比較器
２４，３３　最大値選択回路
２５　制御回路
２６，３４　電圧源
４３　逆流防止回路
４４　逆流防止制御回路
５０　充電システム
５１　ＡＣ－ＤＣ変換器
２４１，３３１　スイッチング回路
２４２，３３２　最大値選択回路の比較器
４３１　ＭＯＳトランジスタ（スイッチング素子）
４３２　整流素子
４３３　抵抗
Ｖｂａｔｔ　電池電圧
Ｖｃｈ　充電電圧
Ｖｃｏｎｔ　逆流防止回路の制御電圧
Ｖｅｎ　充電電圧生成回路の充電状況電圧
Ｖｉｎ　充電電圧生成回路への入力電圧
ＶＬ　充電制御回路の最低動作電圧
Ｖｏ　オフセット電圧
Ｖｏｕｔ　充電電圧生成回路の出力電圧
Ｖｒｅｆ　基準電圧 DESCRIPTION OF SYMBOLS 1,40 Non-contact electric power feeding system 2,32,42 Charging voltage generation circuit 3 Charging control circuit 4 Secondary battery 5 Power transmission control device 6 Primary side control unit 7, 7B, 7C, 7D Secondary side control unit (charging device)
DESCRIPTION OF SYMBOLS 8 Power transmission part 9 Power receiving part 10 Non-contact electric power feeder 11 AC power supply 21 DC-DC converter 22 Offset adder 23 Comparator 24, 33 Maximum value selection circuit 25 Control circuit 26, 34 Voltage source 43 Backflow prevention circuit 44 Backflow prevention control circuit 50 Charging System 51 AC- DC Converters 241 and 331 Switching Circuits 242 and 332 Maximum Value Selection Circuit Comparator 431 MOS Transistor (Switching Element)
432 Rectifier element 433 Resistor Vbatt Battery voltage Vch Charging voltage Vcont Control voltage Ven of backflow prevention circuit Charging status voltage Vin of charging voltage generating circuit Input voltage VL to charging voltage generating circuit Minimum operating voltage Vo of charging control circuit Offset voltage Vout Charging voltage Output voltage Vref of generator circuit Reference voltage

Claims (7)

  1. 　供給電力から二次電池を充電するための充電電圧を生成する充電電圧生成回路と、
    　前記充電電圧生成回路で生成された充電電圧に基づいて前記二次電池を充電するための電流制御を行う充電制御回路とを備え、
    　前記充電電圧生成回路は、スイッチングレギュレータを含み、前記二次電池の電池電圧に応じて前記充電電圧を変化させる、充電装置。     A charging voltage generation circuit that generates a charging voltage for charging the secondary battery from the supplied power; and
    A charge control circuit that performs current control for charging the secondary battery based on the charge voltage generated by the charge voltage generation circuit;
    The charging voltage generation circuit includes a switching regulator, and changes the charging voltage according to a battery voltage of the secondary battery.
  2. 　前記供給電力は、送電部と受電部との間で電力を伝送する非接触給電装置を介して前記送電部から前記受電部へ送られた電力である、請求項１に記載の充電装置。 The charging device according to claim 1, wherein the supplied power is power transmitted from the power transmission unit to the power reception unit via a non-contact power supply device that transmits power between the power transmission unit and the power reception unit.
  3. 　前記充電電圧生成回路は、前記二次電池の電池電圧に予め定められた電圧値を有するオフセット電圧を足し合わせた電圧を前記充電電圧として生成する、請求項１に記載の充電装置。 The charging device according to claim 1, wherein the charging voltage generation circuit generates a voltage obtained by adding an offset voltage having a predetermined voltage value to a battery voltage of the secondary battery as the charging voltage.
  4. 　前記オフセット電圧は、１００ｍＶ以上６００ｍＶ以下である、請求項３に記載の充電装置。 The charging device according to claim 3, wherein the offset voltage is 100 mV or more and 600 mV or less.
  5. 　前記充電電圧生成回路は、前記二次電池の電圧が前記充電制御回路の最低動作電圧以下である場合に、前記最低動作電圧を前記充電電圧として生成する、請求項１に記載の充電装置。 The charging device according to claim 1, wherein the charge voltage generation circuit generates the minimum operation voltage as the charge voltage when the voltage of the secondary battery is equal to or lower than the minimum operation voltage of the charge control circuit.
  6. 　前記充電電圧生成回路と前記二次電池との間に設けられた逆流防止回路を備えている、請求項１に記載の充電装置。 The charging device according to claim 1, further comprising a backflow prevention circuit provided between the charging voltage generation circuit and the secondary battery.
  7. 　前記逆流防止回路は、充電電圧生成回路から二次電池へ向かう方向を順方向とする整流素子と、前記整流素子と並列に接続されたスイッチング素子とを有し、
    　前記充電装置は、前記二次電池の充電開始後に前記スイッチング素子を導通状態にし、前記二次電池の充電後は前記逆流防止回路を非導通状態にする逆流防止制御回路とを有している、請求項６に記載の充電装置。
          The backflow prevention circuit has a rectifying element whose forward direction is a direction from the charging voltage generation circuit to the secondary battery, and a switching element connected in parallel with the rectifying element,
    The charging device includes a backflow prevention control circuit that brings the switching element into a conductive state after starting the charging of the secondary battery and turns the backflow prevention circuit into a non-conductive state after the secondary battery is charged. The charging device according to claim 6.
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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2016190032A1 (en) * 2015-05-25 2016-12-01 日立オートモティブシステムズ株式会社 Power supply apparatus

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP5910358B2 (en) * 2012-07-02 2016-04-27 コニカミノルタ株式会社 Electronics
JP7364069B2 (en) 2020-05-27 2023-10-18 株式会社村田製作所 wireless power receiving device

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH06197468A (en) * 1992-09-24 1994-07-15 Sony Corp Charging device
JPH06253467A (en) * 1993-02-24 1994-09-09 Tokimec Inc Battery charger
JP2006296118A (en) * 2005-04-13 2006-10-26 Matsushita Electric Ind Co Ltd Charger
JP2008199804A (en) * 2007-02-14 2008-08-28 Ricoh Co Ltd Power supply circuit which supplies power to charge control circuit, charging apparatus equipped with the power supply circuit, and method of supplying power to charge control circuit

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH06197468A (en) * 1992-09-24 1994-07-15 Sony Corp Charging device
JPH06253467A (en) * 1993-02-24 1994-09-09 Tokimec Inc Battery charger
JP2006296118A (en) * 2005-04-13 2006-10-26 Matsushita Electric Ind Co Ltd Charger
JP2008199804A (en) * 2007-02-14 2008-08-28 Ricoh Co Ltd Power supply circuit which supplies power to charge control circuit, charging apparatus equipped with the power supply circuit, and method of supplying power to charge control circuit

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2016190032A1 (en) * 2015-05-25 2016-12-01 日立オートモティブシステムズ株式会社 Power supply apparatus
JP2016220454A (en) * 2015-05-25 2016-12-22 日立オートモティブシステムズ株式会社 Electric power supply
CN107431375A (en) * 2015-05-25 2017-12-01 日立汽车系统株式会社 Supply unit
US10541549B2 (en) 2015-05-25 2020-01-21 Hitachi Automotive Systems, Ltd. Power supply apparatus

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