Charging device and method for controlling charging device

Abstract

A charging device for charging a battery, said charging device comprising: a power factor improvement circuit for improving the power factor of an input AC voltage; a converter for converting and outputting the output voltage of the power factor improvement circuit; and a control unit for controlling the switching operation of the converter and switching a rectification method of the converter between a center tap full-wave rectification method and a bridge full-wave rectification method.

Description

Charging device and method for controlling charging device

[0001] The present disclosure relates to a charging device and a method for controlling the charging device.

[0002] Patent Document 1 discloses a technique that can avoid a decrease in power conversion efficiency, avoid the effects of sudden power fluctuations and load fluctuations, and accommodate a wide output voltage range.

[0003] Japanese Patent Application Laid-Open No. 2022-183908

[0004] Generally, charging devices include a power factor correction circuit and an isolated DC / DC converter. However, an isolated DC / DC converter alone cannot accommodate the wide range of output voltages required for battery charging, so a non-isolated DC / DC converter must be provided at the output of the isolated DC / DC converter. This increases the number of parts and the manufacturing process.

[0005] An object of the present disclosure is to provide a charging device and a control method for a charging device that can suppress an increase in the number of parts and accommodate a wide range of output voltages.

[0006] A charging device according to one embodiment of the present disclosure is a charging device for charging a battery, and includes a power factor correction circuit that improves the power factor of an input AC voltage, a converter that converts and outputs the output voltage of the power factor correction circuit, and a control unit that controls the switching operation of the converter and switches the rectification method of the converter between a center-tap full-wave rectification method and a bridge full-wave rectification method.

[0007] In the charging device of the present disclosure, the converter includes a transformer to which the AC voltage output from the power factor correction circuit is inputted to a first winding and which outputs an induced AC voltage from a second winding, a first switching element having a drain electrically connected to the power factor correction circuit and a source electrically connected to one end of the first winding, a second switching element having a drain electrically connected to the source of the first switching element and a source electrically connected to the power factor correction circuit and the other end of the first winding, a first diode, a second diode, a third diode, a fourth diode, a fifth diode, and a third switching element, and an anode of the first diode is electrically connected to one end of the second winding. the cathode of the first diode is electrically connected to the cathode of the second diode, the anode of the second diode is electrically connected to the other end of the second winding, the anode of the third diode is electrically connected to the drain of the third switching element, the cathode of the third diode is electrically connected to the midpoint of the second winding, the anode of the fourth diode is electrically connected to the anode of the fifth diode and the source of the third switching element, the cathode of the fourth diode is electrically connected to the other end of the second winding, and the cathode of the fifth diode is electrically connected to one end of the first winding.

[0008] In the charging device of the present disclosure, the control unit switches the rectification method of the converter between center tap full-wave rectification and bridge full-wave rectification by switching the third switching element on and off.

[0009] In the charging device of the present disclosure, a value half the upper limit value of the charging voltage range of the battery voltage of the battery is set to V ＴＨ When the battery voltage is V ＴＨ If the battery voltage is less than V, the third switching element is turned off, and the rectification method of the converter is switched to a center tap full-wave rectification method, and the battery voltage is V ＴＨ If the above condition is met, the third switching element is turned on to switch the rectification method of the converter to a bridge full-wave rectification method.

[0010] In the charging device of the present disclosure, the control unit ＴＨ When this happens, the output voltage of the converter is V ＴＨ or the converter is stopped.

[0011] A control method for a charging device according to one aspect of the present disclosure is a control method for a charging device for charging a battery, the charging device comprising a power factor correction circuit that corrects the power factor of an input AC voltage and a converter that converts and outputs the output voltage of the power factor correction circuit, and includes a step of controlling the switching operation of the converter to switch the rectification method of the converter between a center-tap full-wave rectification method and a bridge full-wave rectification method.

[0012] According to the present disclosure, it is possible to suppress an increase in the number of parts and accommodate a wide range of output voltages.

[0013] FIG. 1 is a diagram illustrating a configuration example of a charging device according to a comparative example of an embodiment. FIG. 2 is a diagram illustrating a configuration example of a charging device according to an embodiment. FIG. 3 is a diagram illustrating a rectification method control method according to a first example of an embodiment. FIG. 4 is a diagram illustrating a rectification method control method according to a second example of an embodiment. FIG. 5 is a diagram illustrating a rectification method control method according to a third example of an embodiment. FIG. 6 is a diagram illustrating a rectification method control method according to a fourth example of an embodiment. FIG. 7 is a diagram illustrating a rectification method switching method according to the first example of an embodiment. FIG. 8 is a diagram illustrating a rectification method switching method according to the second example of an embodiment.

[0014] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. Note that the present disclosure is not limited to these embodiments, and in the following embodiments, the same components are designated by the same reference numerals, and redundant description will be omitted.

[0015] [Charger] (Comparative Example) A configuration example of a charging device according to a comparative example of the embodiment will be described with reference to Fig. 1. Fig. 1 is a diagram showing a configuration example of a charging device according to a comparative example of the embodiment.

[0016] 1, the charging device 1a includes a power factor correction circuit 10, an isolated DC / DC converter 20a, a non-isolated DC / DC converter 30, and a control unit 40. The charging device 1a is a charging device for charging a rechargeable battery 5.

[0017] The power supply 2 outputs an AC voltage to the power factor correction circuit 10. A fuse 3 and a noise filter 4 are provided between the power supply 2 and the power factor correction circuit 10.

[0018] One end of the fuse 3 is electrically connected to the positive electrode of the power supply 2, and the other end is electrically connected to one input terminal of the noise filter. The fuse 3 is provided to protect the power supply 2. The fuse 3 is, for example, a current fuse that melts due to self-heating when the current passing through it exceeds the rated current.

[0019] The noise filter 4 removes noise components contained in the AC voltage output by the power supply 2 and outputs the voltage to the power factor correction circuit 10. The noise filter 4 removes, for example, ripple noise contained in the output voltage output by the power supply 2.

[0020] The power factor correction circuit 10 corrects the power factor of the AC voltage input from the noise filter 4. The power factor correction circuit 10 outputs a DC voltage that is higher than the DC voltage input from the noise filter 4 to the isolated DC / DC converter 20. The power factor correction circuit 10 includes a capacitor 11, a coupled inductor 12, a diode 13, a switching element 14, a diode 15, a switching element 16, and a capacitor 17.

[0021] One end of the capacitor 11 is electrically connected to one output terminal of the noise filter 4. The other end of the capacitor 11 is electrically connected to the other output terminal of the noise filter 4.

[0022] The coupled inductor 12 includes a first winding 12a, a second winding 12b, and a core 12c. The first winding 12a and the second winding 12b are wound around the core 12c in the same direction.

[0023] One end of the first winding 12a is electrically connected to one end of the capacitor 11. The other end of the first winding 12a is electrically connected to the anode of the diode 13 and the drain of the switching element 14. The cathode of the diode 13 is electrically connected to the cathode of the diode 15. The source of the switching element 14 is electrically connected to the source of the switching element 16.

[0024] One end of the second winding 12b is electrically connected to the other end of the capacitor 11. The other end of the second winding 12b is electrically connected to the anode of the diode 15 and the drain of the switching element 16.

[0025] The switching elements 14 and 16 are controlled to be turned on and off by a control unit 40 .

[0026] One end of the capacitor 17 is electrically connected to the cathodes of the diodes 13 and 15. The other end of the capacitor 17 is electrically connected to the sources of the switching elements 14 and 16.

[0027] Although each switching element according to the present disclosure is an N-channel MOSFET, it is not limited to this, and each switching element according to the present disclosure may be a silicon power device, a GaN power device, a SiC power device, an IGBT (Insulated Gate Bipolar Transistor), or the like.

[0028] Each switching element according to the present disclosure has a parasitic diode. The parasitic diode is a pn junction between the back gate and the source and drain of a MOSFET. The parasitic diode can be used as a freewheeling diode to release transient back electromotive force when each switching element according to the present disclosure is turned off.

[0029] The isolated DC / DC converter 20a is connected to the power factor correction circuit 10. The isolated DC / DC converter 20a includes a first switching element Q1, a second switching element Q2, an inductor Lr, a capacitor Cr, a transformer T, a first diode D1, a second diode D2, and a capacitor Co.

[0030] The drain of the first switching element Q1 is electrically connected to one end of the capacitor 17. The source of the first switching element Q1 is electrically connected to the drain of the second switching element Q2. The source of the second switching element Q2 is electrically connected to the other end of the capacitor 17.

[0031] The transformer T includes a first winding 21a, a second winding 21b, and a core 21c. The first winding 21a and the second winding 21b are wound around the core 21c.

[0032] One end of the inductor Lr is electrically connected to the source of the first switching element Q1 and the drain of the second switching element Q2. The other end of the inductor Lr is electrically connected to one end of the first winding 21a. The inductor Lr is a leakage inductance of the transformer T. The inductor Lr may be a wound component or a wiring inductance.

[0033] One end of the capacitor Cr is electrically connected to the source of the second switching element Q2, and the other end of the capacitor Cr is electrically connected to the other end of the first winding 21a.

[0034] One end of the second winding 21b is electrically connected to the anode of the first diode D1, and the other end of the second winding 21b is electrically connected to the anode of the second diode D2.

[0035] The cathode of the first diode D1 and the cathode of the second diode D2 are electrically connected to one end of the capacitor Co. The other end of the capacitor Co is electrically connected to the midpoint of the second winding 21b.

[0036] The non-insulated DC / DC converter 30 is connected to the isolated DC / DC converter 20. The non-insulated DC / DC converter 30 outputs a DC voltage to the rechargeable battery 5. The non-insulated DC / DC converter 30 includes a switching element 31, a switching element 32, an inductor 33, a capacitor 34, and a fuse 35.

[0037] The drain of the switching element 31 is electrically connected to one end of the capacitor Co. The source of the switching element 31 is electrically connected to one end of the inductor 33.

[0038] The drain of the switching element 32 is electrically connected to one end of the inductor 33. The source of the switching element 32 is electrically connected to the other end of the capacitor Co.

[0039] The other end of the inductor 33 is electrically connected to one end of the capacitor 34. The other end of the capacitor 34 is electrically connected to the source of the switching element 32 and the low potential side of the rechargeable battery 5.

[0040] One end of the fuse 35 is electrically connected to one end of the capacitor 34, and the other end is electrically connected to the high potential side of the rechargeable battery 5. The fuse 35 is provided to protect the rechargeable battery 5. The rechargeable battery 5 is, for example, a current fuse that melts due to self-heating when the current passing through it exceeds the rated current.

[0041] The control unit 40 controls the power factor correction circuit 10, the isolated DC / DC converter 20a, and the non-isolated DC / DC converter 30. The control unit 40 includes, for example, an information processing device such as a DSP (Digital Signal Processor) with a built-in digital PWM (Pulse Width Modulation) circuit, a CPU (Central Processing Unit), or an MPU (Micro Processing Unit), and a storage device such as a RAM (Random Access Memory) or a ROM (Read Only Memory). The control unit 40 may be implemented by, for example, an integrated circuit such as an ASIC (Application Specific Integrated Circuit) or an FPGA (Field Programmable Gate Array). The control unit 40 may also be implemented by a combination of hardware and software.

[0042] 1, in the comparative example, in order to accommodate the wide range of output voltages required for battery charging, a non-insulated DC / DC converter 30 is provided at the output of an isolated DC / DC converter 20. As a result, the comparative example requires an increased number of parts and therefore requires an increased number of manufacturing steps.

[0043] Therefore, an object of the present disclosure is to provide a charging device and a control method for a charging device that can suppress an increase in the number of parts and can accommodate a wide range of output voltages.

[0044] (Embodiment) An example of the configuration of a charging device according to an embodiment will be described with reference to Fig. 2. Fig. 2 is a diagram showing an example of the configuration of a charging device according to an embodiment.

[0045] As shown in FIG. 2 , the charging device 1 includes a power factor correction circuit 10 , an isolated DC / DC converter 20 , a control unit 40 , a voltage detection unit 51 , a voltage detection unit 52 , and a voltage detection unit 53 .

[0046] The isolated DC / DC converter 20 includes a first switching element Q1, a second switching element Q2, a third switching element Q3, a first diode D1, a second diode D2, a third diode D3, a fourth diode D4, a fifth diode D5, an inductor Lr, a capacitor Cr, and a capacitor Co. The isolated DC / DC converter 20 outputs a DC voltage to the rechargeable battery 5. Note that the isolated DC / DC converter usable in the present disclosure may be of any circuit type, such as an LLC type or a phase shift type, as long as the secondary side is a DC / DC converter capable of center-tap full-wave rectification.

[0047] The isolated DC / DC converter 20 differs from the isolated DC / DC converter 20a according to the comparative example shown in FIG. 1 in that it includes a third switching element Q3 and third to fifth diodes D3 to D5.

[0048] The cathode of the third diode D3 is electrically connected to the midpoint of the second winding 21b, and the anode of the third diode D3 is electrically connected to the drain of the third switching element Q3.

[0049] The cathode of the fourth diode D4 is electrically connected to the other end of the second winding 21b. The anode of the fourth diode D4 is electrically connected to the anode of the fifth diode D5 and the source of the third switching element Q3. The cathode of the fifth diode D5 is electrically connected to one end of the second winding 21b.

[0050] The control unit 40 controls the switching operation of the isolated DC / DC converter 20 to switch the rectification method of the isolated DC / DC converter 20 between center tap full-wave rectification and bridge full-wave rectification. Specifically, the control unit 40 switches the rectification method of the isolated DC / DC converter 20 between center tap full-wave rectification and bridge full-wave rectification by switching on and off the first to third switching elements Q1 to Q3.

[0051] The anode of the sixth diode D6 is electrically connected to one end of the capacitor Co. The cathode of the sixth diode D6 is electrically connected to one end of the fuse 6. The other end of the fuse 6 is electrically connected to the high potential side of the rechargeable battery 5.

[0052] The fuse 6 is provided to protect the rechargeable battery 5. The fuse 6 is, for example, a current fuse that melts down due to self-heating when the current passing through it exceeds the rated current.

[0053] The voltage detection unit 51 has one input terminal electrically connected to one end of the capacitor 17 and the other input terminal electrically connected to the other end of the capacitor 17. The voltage detection unit 51 detects the output voltage output from the power factor correction circuit 10. The voltage detection unit 51 outputs a detection signal V DC＿ＬＩＮＫ is output to the control unit 40.

[0054] The voltage detection unit 52 has one input terminal electrically connected to one end of the capacitor Co and the other input terminal electrically connected to the other end of the capacitor Co. The voltage detection unit 52 detects the output voltage output from the isolated DC / DC converter 20. The voltage detection unit 51 outputs a detection signal Vo indicating the voltage detection result to the control unit 40.

[0055] One input terminal of the voltage detection unit 53 is electrically connected to the high potential side of the rechargeable battery 5 via the fuse 6, and the other input terminal is electrically connected to the low potential side of the rechargeable battery 5. The voltage detection unit 53 detects the battery voltage of the rechargeable battery 5. The voltage detection unit 53 outputs a detection signal V ＢＡＴＴ is output to the control unit 40.

[0056] The control unit 40 controls the on / off of the first to third switching elements Q1 to Q3 based on the detection signals received from the voltage detection units 51 to 53, for example.

[0057] [Rectification Method Control Method] (First Example) A rectification method control method according to a first example of the embodiment will be described with reference to Fig. 3. Fig. 3 is a diagram for explaining the rectification method control method according to the first example of the embodiment.

[0058] 3 , the control unit 40 controls the first switching element Q1 to be on, the second switching element Q2 to be off, and the third switching element Q3 to be off. In this case, as shown by arrow 101, a current flows on the primary side of the isolated DC / DC converter 20 in the order of the first switching element Q1, inductor Lr, first winding 21a, and capacitor Cr. As shown by arrow 102, a current flows on the secondary side of the isolated DC / DC converter 20 in the order of the third diode D3, the midpoint of the second winding 21b, the upper side of the second winding 21b, and first diode D1. In this case, the rectification method of the isolated DC / DC converter 20 is center-tap full-wave rectification.

[0059] (Second Example) A rectification method control method according to a second example of the embodiment will be described with reference to Fig. 4. Fig. 4 is a diagram for explaining a rectification method control method according to the second example of the embodiment.

[0060] 4 , the control unit 40 controls the first switching element Q1 to be turned off, the second switching element Q2 to be turned off, and the third switching element Q3 to be turned off. In this case, as indicated by arrow 103, a current flows circulatingly on the primary side of the isolated DC / DC converter 20 in the order of the second switching element Q2, capacitor Cr, first winding 21a, and inductor Lr. As indicated by arrow 104, a current flows on the secondary side of the isolated DC / DC converter 20 in the order of the third diode D3, the midpoint of the second winding 21b, the lower side of the second winding 21b, and second diode D2. In this case, the rectification method of the isolated DC / DC converter 20 is center-tap full-wave rectification.

[0061] That is, when the third switching element Q3 is off, the rectification method of the isolated DC / DC converter 20 is the center tap full-wave rectification method.

[0062] (Third Example) A rectification method control method according to a third example of the embodiment will be described with reference to Fig. 5. Fig. 5 is a diagram for explaining a rectification method control method according to the third example of the embodiment.

[0063] 5 , the control unit 40 controls the first switching element Q1 to be on, the second switching element Q2 to be off, and the third switching element Q3 to be on. In this case, as shown by arrow 105, a current flows on the primary side of the isolated DC / DC converter 20 in the order of the first switching element Q1, inductor Lr, first winding 21a, and inductor Lr. As shown by arrow 105, a current flows on the secondary side of the isolated DC / DC converter 20 in the order of the third switching element Q3, fourth diode D4, the lower side of the second winding 21b, the midpoint of the second winding 21b, the upper side of the second winding 21b, and first diode D1. In this case, the rectification method of the isolated DC / DC converter 20 is a bridge full-wave rectification method.

[0064] (Fourth Example) A rectification method control method according to a fourth example of the embodiment will be described with reference to Fig. 6. Fig. 6 is a diagram for explaining a rectification method control method according to the fourth example of the embodiment.

[0065] 6 , the control unit 40 controls the first switching element Q1 to be OFF, the second switching element Q2 to be ON, and the third switching element Q3 to be ON. In this case, as indicated by arrow 107, a current flows circulatingly on the primary side of the isolated DC / DC converter 20 in the order of the second switching element Q2, capacitor Cr, first winding 21a, and inductor Lr. As indicated by arrow 108, a current flows on the secondary side of the isolated DC / DC converter 20 in the order of the third switching element Q3, fifth diode D5, the upper side of the second winding 21b, the midpoint of the second winding 21b, the lower side of the second winding 21b, and second diode D2. In this case, the rectification method of the isolated DC / DC converter 20 is a bridge full-wave rectification method.

[0066] That is, when the third switching element Q3 is on, the rectification method of the isolated DC / DC converter 20 is the center tap full-wave rectification method.

[0067] [Method of Switching Rectification Methods] (First Example) A method of switching rectification methods according to a first example of the embodiment will be described with reference to Fig. 7. Fig. 7 is a diagram for explaining a method of switching rectification methods according to the first example of the embodiment.

[0068] The rectification method switching method according to the first example of the embodiment is a method of reducing the output voltage of the isolated DC / DC converter 20 when switching the rectification method.

[0069] 7, a waveform 201 represents the change over time in the battery voltage of the rechargeable battery 5. A waveform 202 represents the change over time in the output voltage of the isolated DC / DC converter 20. A waveform 203 represents the operation of the third switching element Q3.

[0070] 7, the period from timing t0 to timing t1 is the center tap full-wave rectification period, the period from timing t1 to timing t3 is the rectification method switching period, and the period from timing t3 onwards is the bridge full-wave rectification period.

[0071] Voltage V ＴＨ is the threshold value for switching the rectification method. ＴＨis, for example, half the upper limit of the charging voltage range of the rechargeable battery 5. The control unit 40 determines whether the battery voltage of the rechargeable battery 5 is equal to or lower than the voltage V ＴＨ Specifically, the control unit 40 switches the rectification method of the isolated DC / DC converter 20 depending on whether the charging voltage of the rechargeable battery 5 is less than the voltage V ＴＨ When the charging voltage of the rechargeable battery 5 is less than the voltage V, the control unit 40 controls the third switching element Q3 to be turned off, and switches the rectification method of the isolated DC / DC converter 20 to the center tap full wave rectification method. ＴＨ When this occurs, the third switching element Q3 is controlled to be on, and the rectification method of the isolated DC / DC converter 20 is switched to the bridge full-wave rectification method.

[0072] In the example shown in FIG. 7, at timing t1, the battery voltage of the rechargeable battery 5 is V ＴＨ In this case, the control unit 40 controls the output voltage of the isolated DC / DC converter 20 to the voltage V ＴＨ The control unit 40 then controls the output voltage of the isolated DC / DC converter 20 to be less than the voltage V ＴＨ At timing t2 when the voltage Vcc becomes less than 1 / 2, the third switching element Q3 is switched from off to on, whereby the rectification method of the isolated DC / DC converter 20 transitions to bridge full-wave rectification at timing t3.

[0073] (Second Example) A method of switching between rectification methods according to a second example of the embodiment will be described with reference to Fig. 8. Fig. 8 is a diagram for explaining a method of switching between rectification methods according to the second example of the embodiment.

[0074] The rectification method switching method according to the second example of the embodiment is a method of stopping the output voltage of the isolated DC / DC converter 20 when switching the rectification method.

[0075] 8, waveform 211 represents the change over time in the battery voltage of the rechargeable battery 5. Waveform 212 represents the change over time in the output voltage of the isolated DC / DC converter 20. Waveform 213 represents the operation of the third switching element Q3. Waveform 214 represents the operation of the first switching element Q1. Waveform 215 represents the operation of the second switching element Q2.

[0076] 8, the period from timing t10 ​​to timing t11 is the center tap full-wave rectification period, the period from timing t11 to timing t13 is the rectification method switching period, and the period after timing t13 is the bridge full-wave rectification period.

[0077] In the example shown in FIG. 8, at timing t11, the battery voltage of the rechargeable battery 5 is V ＴＨ This is the end. In this case, the control unit 40 stops the output voltage of the isolated DC / DC converter 20. Specifically, the control unit 40 keeps the first switching element Q1 in an OFF state and keeps the second switching element Q2 in an ON state. Then, when the control unit 40 turns the first switching element Q1 OFF and the second switching element Q2 ON, it turns the third switching element Q3 from OFF to ON. As a result, the rectification method of the isolated DC / DC converter 20 transitions to bridge full-wave rectification at timing t13.

[0078] By switching as in the first or second example, it is possible to prevent a strange output voltage from being output at the time of switching.

[0079] As described above, in the present disclosure, the rectification method of the isolated DC / DC converter 20 is switched between center-tap full-wave rectification and bridge full-wave rectification depending on the magnitude of the battery voltage. This allows the present disclosure to omit the non-isolated DC / DC converter that is typically required, thereby minimizing the increase in the number of components and configuring a charging device that can accommodate a wide range of output voltages. Therefore, the present disclosure can charge various batteries with different battery voltages, eliminating the need to develop a dedicated charging device for each battery.

[0080] Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the contents of these embodiments. Furthermore, the above-described components include those that can be easily imagined by a person skilled in the art, those that are substantially the same, and those that are within the so-called equivalent range. Furthermore, the above-described components can be combined as appropriate. Furthermore, various omissions, substitutions, or modifications of the components can be made without departing from the spirit of the above-described embodiments.

[0081] REFERENCE SIGNS LIST 1, 1a Charging device 2 Power supply 3, 6, 35 Fuse 4 Noise filter 5 Charging battery 10 Power factor correction circuit 11, 17, 34, Cr, Co Capacitor 12 Coupled inductor 12a, 21a First winding 12b, 21b Second winding 12c, 21c Core 13, 15 Diode 14, 16, 31, 32 Switching element 20, 20a Isolated DC / DC converter 30 Non-isolated DC / DC converter 33, Lr Inductor 40 Control unit 51, 52, 53 Voltage detection unit D1 First diode D2 Second diode D3 Third diode D4 Fourth diode D5 Fifth diode D6 Sixth diode T Transformer

Claims

1. A charging device for charging a battery, comprising: a power factor correction circuit that corrects the power factor of an input AC voltage; a converter that converts and outputs the output voltage of the power factor correction circuit; and a control unit that controls the switching operation of the converter and switches the rectification method of the converter between a center-tap full-wave rectification method and a bridge full-wave rectification method.

2. The converter includes: a transformer to which the AC voltage output from the power factor correction circuit is inputted to a first winding and which outputs an induced AC voltage from a second winding; a first switching element having a drain electrically connected to the power factor correction circuit and a source electrically connected to one end of the first winding; a second switching element having a drain electrically connected to the source of the first switching element and a source electrically connected to the power factor correction circuit and the other end of the first winding; a first diode, a second diode, a third diode, a fourth diode, a fifth diode, and a third switching element, wherein the anode of the first diode is electrically connected to one end of the second winding and the cathode of the first diode is electrically connected to the cathode of the second diode; the anode of the second diode is electrically connected to the other end of the second winding; the anode of the third diode is electrically connected to the drain of the third switching element and the cathode of the third diode is electrically connected to a midpoint of the second winding; 2. The charging device according to claim 1, wherein an anode of the fourth diode is electrically connected to an anode of the fifth diode and a source of the third switching element, a cathode of the fourth diode is electrically connected to the other end of the second winding, and a cathode of the fifth diode is electrically connected to one end of the first winding.

3. The charging device according to claim 2, wherein the control unit switches the rectification method of the converter between a center tap full-wave rectification method and a bridge full-wave rectification method by switching the third switching element on and off.

4. Set half the upper limit of the charging voltage range of the battery voltage of the battery to V ＴＨ When the battery voltage is V ＴＨ If the battery voltage is less than V, the third switching element is turned off, and the rectification method of the converter is switched to a center tap full-wave rectification method, and the battery voltage is V ＴＨ The charging device according to claim 3 , wherein when the voltage is equal to or greater than the voltage, the third switching element is turned on to switch the rectification method of the converter to a bridge full-wave rectification method.

5. The control unit determines whether the battery voltage is V ＴＨ When this happens, the output voltage of the converter is V ＴＨ 5. The charging device according to claim 4, wherein the converter is controlled so that the difference is less than 1 / 2 or the converter is stopped.

6. A control method for a charging device for charging a battery, the charging device comprising a power factor correction circuit for correcting the power factor of an input AC voltage, and a converter for converting and outputting the output voltage of the power factor correction circuit, the control method for a charging device including a step of controlling the switching operation of the converter to switch the rectification method of the converter between a center tap full-wave rectification method and a bridge full-wave rectification method.

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