Vehicle and vehicle charging control method

Abstract

The invention relates to a vehicle and a charging control method of the vehicle. A vehicle includes: a plurality of single-phase battery module systems including a plurality of battery modules and provided for each phase of a motor, each of the battery modules including a battery and a power conversion module, and a plurality of inductors provided for each phase of the motor; the power conversion module includes an inverter configured to convert a DC voltage stored in the battery into an AC voltage to control the motor; a plurality of inductors connected to each of the plurality of single-phase battery module systems; the inverter may be configured to receive an AC voltage from the AC power source through the plurality of inductors and charge the battery during charging.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of priority from Korean Patent Application No. 10-2023-0104975 filed on August 10, 2023, in the Korean Intellectual Property Office, and Korean Patent Application No. 10-2024-0100937 filed on July 30, 2024, in the Korean Intellectual Property Office, the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present invention relates to a vehicle and a charging control method of the vehicle. Background Art

[0004] It should be noted that the contents described in this section only provide background information related to the present invention and do not constitute prior art.

[0005] The environmentally friendly vehicle may refer to a hybrid electric vehicle, an electric vehicle, a fuel cell electric vehicle, etc., and may include a high-voltage battery pack, an inverter, a motor, and the like.

[0006] The driving system of such an environmentally friendly vehicle may include a battery pack and an inverter as separate devices, and may be configured to charge the high-voltage battery pack using an on-board charger (OBC) installed in the vehicle during slow charging. Summary of the invention

[0007] One aspect of the present invention provides a vehicle and a charging control method of the vehicle, which can reduce the cost of a charger, reduce the overall volume by eliminating the need for an additional on-board charger, and can achieve fast charging compared to existing on-board chargers with limited capacity.

[0008] According to one aspect of the present invention, a vehicle is provided, comprising: a plurality of single-phase battery module systems having a plurality of battery modules and arranged for each phase of a motor, and a plurality of inductors, wherein each of the battery modules comprises a battery and a power conversion module, the power conversion module comprises an inverter configured to convert a DC voltage stored in the battery into an AC voltage to control the motor; a plurality of inductors are connected to each of the plurality of single-phase battery module systems; and the inverter can be configured to receive an AC voltage from an AC power source through the plurality of inductors during charging and charge the battery.

[0009] According to an exemplary embodiment of the present invention, the battery and the input terminal of the inverter may be connected in parallel, and the output terminal of the inverter may be connected in series to the output terminal of the inverter included in the adjacent battery module.

[0010] According to an exemplary embodiment of the present invention, one end of each of the plurality of inductors may be connected to each other and to an AC power source, and the other end of each of the plurality of inductors may be connected to a plurality of single-phase battery module systems.

[0011] According to an exemplary embodiment of the present invention, the other end of each of the plurality of inductors may be connected to one of output ends of an inverter included in one of the plurality of battery modules included in each of the plurality of single-phase battery module systems.

[0012] According to an exemplary embodiment of the present invention, another output terminal of the output terminal of the inverter included in one of the battery modules included in any one of the multiple single-phase battery module systems can be connected to another output terminal of the output terminal of the inverter included in one of the multiple battery modules included in another single-phase battery module system in the multiple single-phase battery module systems and connected to an AC power supply.

[0013] According to an example embodiment of the present invention, the inverter may include: an upper switch and a lower switch arranged in a first branch and connected in series, and an upper switch and a lower switch arranged in a second branch and connected in series, one of the output terminals of the inverter may be between the upper switch and the lower switch of the first branch, and the other of the output terminals of the inverter may be between the upper switch and the lower switch of the second branch.

[0014] According to an example embodiment of the present invention, one of the plurality of single-phase battery module systems may include the same number of battery modules as another of the plurality of single-phase battery module systems.

[0015] According to an exemplary embodiment of the present invention, an inverter includes an H-bridge single-phase inverter provided with a plurality of power semiconductor elements.

[0016] According to an exemplary embodiment of the present invention, when the polarity of the AC power source is positive (+), the upper switch of the first branch and the lower switch of the second branch can be turned on, and when the polarity of the AC power source is negative (-), the lower switch of the first branch and the upper switch of the second branch can be turned on to charge the battery.

[0017] According to an exemplary embodiment of the present invention, the charging amount of the battery is controlled based on the amount of current flowing through the inductor according to the duty ratio of the turned-on switch.

[0018] According to an exemplary embodiment of the present invention, the inverter includes a switch that can be switched according to the frequency and phase of the AC power source.

[0019] According to an exemplary embodiment of the present invention, the inductor may be a separately provided inductor instead of a stator winding of the motor.

[0020] According to an exemplary embodiment of the present invention, the vehicle may further include a plurality of upper switches provided between the other end of each of the plurality of inductors and each of the plurality of single-phase battery module systems.

[0021] According to an exemplary embodiment of the present invention, a charging control method for a vehicle is provided, wherein the vehicle includes a plurality of single-phase battery module systems having a plurality of battery modules and arranged for each phase of a motor, and a plurality of inductors, wherein each of the battery modules includes a battery and a power conversion module, the power conversion module includes an inverter configured to convert a DC voltage stored in the battery into an AC voltage to control the motor, and a plurality of inductors are connected to each of the plurality of single-phase battery module systems, and the method includes: a receiving step, in which a charging signal for AC charging is received from a charger; and a control step, in which, when the charging signal is received, an AC voltage is received from an AC power source through the plurality of inductors and the inverter is controlled to charge the battery.

[0022] According to an exemplary embodiment of the present invention, the inverter may include an upper switch and a lower switch arranged in a first branch and connected in series, and an upper switch and a lower switch arranged in a second branch and connected in series; in a control step, when the polarity of the AC power supply is positive (+), the upper switch of the first branch and the lower switch of the second branch may be turned on, and when the polarity of the AC power supply is negative (-), the lower switch of the first branch and the upper switch of the second branch may be turned on.

[0023] According to an exemplary embodiment of the present invention, in the controlling step, according to the duty ratio of the turned-on switch, the charging amount of the battery charging may be controlled based on the amount of current flowing through the inductor.

[0024] According to an exemplary embodiment of the present invention, the motor can be driven by multiple low-voltage battery modules, which integrate batteries and inverters into a single module for each phase of the motor, but the inverter can be used to charge the battery during the charging process, so there is no need to install an additional on-board charger, thereby reducing the cost of the charger and reducing the overall volume.

[0025] Furthermore, according to an exemplary embodiment of the present invention, the output and capacity of the inverter can be freely increased by combining a plurality of battery modules in series or in parallel, thereby enabling faster charging compared to existing on-board chargers with limited capacity (e.g., 3kW to 10kW). BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The above and other aspects, features and advantages of the present invention will be more clearly understood from the following detailed description presented in conjunction with the accompanying drawings, in which:

[0027] Figure 1 An electric vehicle drive system including a conventional high voltage battery pack is shown;

[0028] Figure 2 and Figure 3 shows a battery module according to an exemplary embodiment of the present invention;

[0029] Figure 4 is a schematic diagram showing a connection structure between a plurality of battery modules according to an exemplary embodiment of the present invention;

[0030] Figure 5 A single-phase battery module system according to an exemplary embodiment of the present invention is shown;

[0031] Figure 6 is a schematic diagram showing a connection relationship of an inverter in a three-phase battery module system according to an exemplary embodiment of the present invention;

[0032] Figure 7 is a schematic diagram showing a connection relationship of a first DC / DC converter in a three-phase battery module system according to an exemplary embodiment of the present invention;

[0033] Figure 8 is a schematic diagram showing a connection relationship of a second DC / DC converter in a three-phase battery module system according to an exemplary embodiment of the present invention;

[0034] Fig. 9 is a schematic diagram showing a structure of an inverter according to an exemplary embodiment of the present invention;

[0035] Fig.10 is a block diagram of a vehicle according to an exemplary embodiment of the present invention;

[0036] Fig.11 and Fig.12 is a schematic diagram showing a charging path according to the polarity of an AC power source;

[0037] Fig.13 is a flowchart illustrating a charging control method of a vehicle according to an exemplary embodiment of the present invention; and

[0038] Fig.14 is a block diagram of a computing device that can fully or partially implement a control module according to an exemplary embodiment of the present invention. DETAILED DESCRIPTION

[0039] Hereinafter, specific exemplary embodiments of the present invention will be described with reference to the accompanying drawings. The following detailed description is provided to help fully understand the methods, devices and / or systems described in this specification. However, the detailed description is only for illustrative purposes and the present invention is not limited thereto.

[0040] When describing the exemplary embodiments of the present invention in detail, when it is determined that the detailed description of the known technology related to the present invention may unnecessarily obscure the gist of the present invention, its detailed description will be omitted. In addition, the terms described below are defined in view of the functions in the present invention and can be changed according to the intention or practice of the user or operator. Therefore, its definition should be based on the content in this specification. The terms used in the specification are intended to be used to describe the embodiments and are by no means restrictive. Unless otherwise expressly used, the expression in the singular includes the meaning of the plural form. In this specification, expressions such as "including" or "comprising" are intended to indicate features, values, steps, operations, elements, parts or combinations thereof, and should not be interpreted as excluding the existence or possibility of one or more other features, values, steps, operations, elements, parts or combinations thereof.

[0041] In addition, the “module voltage” described below may refer to a voltage output from a battery module, and the “system voltage” may refer to a voltage output from a battery module system configured based on the battery module.

[0042] The battery module described below may include a battery module for a vehicle, and the battery module system may include a single-phase battery module system for a vehicle and a three-phase battery module system for a vehicle.

[0043] Furthermore, the present invention can be applied not only to vehicles but also to various devices to which battery modules and battery module systems are applicable.

[0044] Figure 1 is a diagram showing a configuration of an electric vehicle drive system including a conventional high-voltage battery pack.

[0045] like Figure 1 As shown, a driving system 1 of an environmentally friendly vehicle includes an on-board charger (OBC) 3 for slow charging, a high-voltage battery pack 4 , an inverter 5 including a DC bus capacitor C, and a motor 6 .

[0046] According to these configurations, the OBC 3 for slow charging converts the commercial AC voltage provided by the AC power source 2 into a DC voltage to charge the high-voltage battery pack 4 , and the inverter 5 converts the DC voltage stored in the high-voltage battery pack 4 into an AC voltage to drive the motor 6 .

[0047] Since the driving system 1 of such an environmentally friendly vehicle should be equipped with a separate OBC 3 for slow charging, there are disadvantages that the driving system 1 is expensive and bulky. In addition, since the capacity of the existing OBC 3 (eg, 3 kW to 10 kW) is small, charging takes a long time.

[0048] In addition, since the driving system 1 of the environmentally friendly vehicle operates at a high voltage (e.g., 400V to 800V), high-voltage components should be used, but high-voltage components are more expensive than components operating at a low voltage and have the disadvantage of generating a large amount of heat. Specifically, SiC power semiconductors for high-voltage switches are applied to inverters 5 operating at a high voltage, but the production of SiC power semiconductors is low relative to high demand, making it difficult to stabilize supply and demand, and are relatively expensive.

[0049] On the other hand, since the high voltage battery pack 4 has only one type of high voltage output, various power conversion devices need to be applied to the eco-friendly vehicle. This is because the eco-friendly vehicle has electrical loads of various functions, and the voltage required for each electrical load is different.

[0050] For example, an environmentally friendly vehicle may have electrical loads that require various voltages, such as a low-voltage load such as a radio that operates at a low-voltage DC voltage (e.g., 12V to 24V), a high-voltage load such as an air conditioning system that operates at a high-voltage DC voltage (e.g., 400V to 800V), and a motor that operates at a high-voltage three-phase AC voltage (e.g., 400V to 800V), and thus various types of voltages are required depending on the type of component.

[0051] Various power conversion devices may lose energy in the process of converting electricity from high voltage to low voltage, which may reduce efficiency and may further require a separate transformer because the voltage should be significantly reduced.

[0052] Furthermore, the drive system 1 of the environmentally friendly vehicle should have a capacitor for each of the various power conversion devices, and the need for a high-capacity capacitor makes the drive system 1 expensive and occupies a large volume.

[0053] In addition, the driving system 1 of a conventional environmentally friendly vehicle has the following disadvantages: when any one of the battery cells included in the high-voltage battery pack 4 malfunctions, the entire high-voltage battery pack 4 should be replaced, and when any one component malfunctions, the entire system may stop, which may reduce the reliability of the entire system.

[0054] Meanwhile, in the driving system 1 of the conventional environmentally friendly vehicle, each PE system should be designed according to different specifications depending on the vehicle type, which may complicate the process and increase the production cost.

[0055] The battery module system according to an exemplary embodiment of the present invention described below may be configured by a series / parallel combination of a plurality of battery modules, each of which may include a low voltage battery and a power conversion device operating at a low voltage, such as an inverter and a converter.

[0056] In other words, the battery module system according to the exemplary embodiment of the present invention can be configured based on the battery module, and since each battery module includes a power conversion device, the battery module system can not only store / release electrical energy, but also perform power conversion in the battery module. Accordingly, the battery module according to the exemplary embodiment of the present invention can convert DC power into AC power as needed, or convert the size of the battery power and output the power. In addition, a high voltage output can be formed by connecting the output of each battery module in series, or a high current output can be formed by connecting the output of each battery module in parallel, and the voltage of each battery module can be monitored to perform balancing control. Hereinafter, the battery module according to the exemplary embodiment of the present invention and the battery module system including the battery module will be described in more detail.

[0057] Figure 2 A battery module according to an exemplary embodiment of the present invention is shown.

[0058] refer to Figure 2 , the battery module 10 according to the exemplary embodiment of the present invention may include a battery 110 , an inverter 120 , a first DC / DC converter 130 , and a second DC / DC converter 140 .

[0059] The battery 110 may output a battery voltage and may charge or discharge electric energy. In addition, the battery voltage may be configured as a basic voltage of the battery module 10 and may provide an input voltage to the inverter 120, the first DC / DC converter 130, and the second DC / DC converter 140.

[0060] In addition, the battery 110 may have a battery voltage lower in magnitude than that of a typical high voltage battery pack. Accordingly, the battery module 10 for a vehicle according to an exemplary embodiment of the present invention may apply a power conversion element capable of operating at a low voltage, thereby reducing production costs.

[0061] In addition, according to the battery module 10 of the exemplary embodiment of the present invention, various sizes and types of voltages can be output according to the series / parallel combination of the battery modules 10, so that a single standardized battery module 10 can be used and applied to various standard vehicle models, and the production cost can be reduced.

[0062] For example, when the battery voltage is set to 100 V, four battery modules 10 can be connected in series to form a battery module system that outputs a voltage of 400 V, and eight battery modules 10 can be connected in series to form a battery module system that outputs a voltage of 800 V. In addition, for example, when the battery voltage is set to 50 V, eight battery modules 10 can be connected in series to form a battery module system that outputs a voltage of 400 V, and sixteen battery modules 10 can be connected in series to form a battery module system that outputs a voltage of 800 V.

[0063] In addition, a single-phase battery module system can be configured by connecting the battery modules 10 in series and outputting a high-voltage AC voltage using the output of the inverter 120, and a plurality of single-phase battery module systems can be used to output a three-phase AC voltage. In addition, a battery module system through which a high current flows can be formed by combining the battery modules 10 in parallel.

[0064] The inverter 120 can convert the battery voltage into an AC module voltage and output the voltage. In addition, the inverter 120 may include input terminals 120a and 120b and output terminals 120c and 120d, the input terminals 120a and 120b of the inverter may be connected in parallel to the battery 110 to receive the battery voltage, and the output terminals 120c and 120d of the inverter 120 may output the AC module voltage. Hereinafter, the output terminals 120c and 120d of the inverter 120 may be referred to as the AC module output terminals that output the AC module voltage. In addition, the inverter 120 may be configured to supply AC power according to the AC module voltage to the AC load. In this case, the AC load may be a load (e.g., a motor) that utilizes an AC voltage as a driving voltage.

[0065] In addition, the first DC / DC converter 130 may convert the battery voltage into a first DC module voltage which is lower than the battery voltage, and may output the first DC module voltage.

[0066] In addition, the first DC module voltage can be set to a driving voltage of a low-voltage load. For example, the low-voltage load can be an electrical load such as various lights and radios, infotainment, etc. of an electric vehicle. In addition, the first DC module voltage can be set to 12V, 24V, or 48V, which is a driving voltage of a low-voltage load. However, the voltage amplitude mentioned in this article is only an example, and can be set to a voltage with various amplitudes according to the design.

[0067] In addition, the first DC / DC converter 130 may include input terminals 130a and 130b and output terminals 130c and 130d. The input terminals 130a and 130b of the first DC / DC converter may be connected in parallel to the battery to receive the battery voltage, and the output terminals 130c and 130d of the first DC / DC converter may output the first DC module voltage. Hereinafter, the output terminals 130c and 130d of the first DC / DC converter may be referred to as the first DC module output terminals, which output the first DC module voltage.

[0068] In addition, the output terminals 130 c and 130 d of the first DC / DC converter may be directly connected to a low voltage load to provide a first DC module voltage.

[0069] In an exemplary embodiment, one output terminal 130d of the output terminals of the first DC / DC converter 130 may be grounded, and another output terminal 130c of the output terminals of the first DC / DC converter 130 may be connected to a low voltage load to output the first DC module voltage. In another exemplary embodiment, both output terminals of the first DC / DC converter may be connected to both ends of the low voltage load to output the first DC module voltage.

[0070] In addition, the second DC / DC converter 140 may convert the battery voltage into a second DC module voltage and output the second DC module voltage. The second DC module voltage may be set to a value greater than the first DC module voltage output from the first DC / DC converter 130. In addition, the second DC module voltage may be lower than or equal to the battery voltage, or may be higher than the battery voltage.

[0071] In addition, the second DC module voltage output from the second DC / DC converter 140 can be connected in series to the second DC module voltage output from another battery module 10 to provide power to the high-voltage load. In other words, the second DC module voltage output from the second DC / DC converter 140 may not be used as a single output to provide power to the high-voltage load, but may be connected in series to the second DC module voltage of another battery module 10 to provide power to the high-voltage load. The battery voltage included in the battery module 10 may be formed as a low voltage. Accordingly, in order to provide voltage to a high-voltage load such as an air conditioning system, a plurality of battery modules 10 may be combined in series with each other to provide a high voltage. In other words, the output terminals 140c and 140d of the second DC / DC converter 140 may be connected in series to the output terminals of the second DC / DC converter of another battery module to form a high voltage, thereby providing power to the high-voltage load.

[0072] In addition, the second DC / DC converter 140 may include input terminals 140a and 140b and output terminals 140c and 140d. The input terminals 140a and 140b of the second DC / DC converter 140 may be connected in parallel to the battery 110 to receive the battery voltage, and the output terminals 140c and 140d of the second DC / DC converter may output the second DC module voltage. As used herein, the output terminals 140c and 140d of the second DC / DC converter may also be referred to as second DC module output terminals, which output the second DC module voltage.

[0073] In addition, the output terminals 140c and 140d of the second DC / DC converter can be connected in series to the output terminals of the second DC / DC converter included in another battery module, or can be connected to a high voltage load. In this case, the specific connection structure with another battery module 10 will be described below.

[0074] In addition, the battery 110 may be connected in parallel to the input terminals 120a and 120b of the inverter, the input terminals 130a and 130b of the first DC / DC converter, and the input terminals 140a and 140b of the second DC / DC converter.

[0075] Figure 3 A battery module according to an exemplary embodiment of the present invention is shown.

[0076] refer to Figure 3 , the battery module 20 according to the exemplary embodiment of the present invention may include: a battery 210, an inverter 220, a first DC / DC converter 230, a second DC / DC converter 240, and a common capacitor 250. In addition, the common capacitor 250 may be connected to the battery 210 in parallel. Figure 3 The battery module 20 shown may include Figure 2 All components of the battery module 10 are shown, and may further include a common capacitor 250 .

[0077] According to the battery module 20 of the exemplary embodiment of the present invention, a common capacitor can be shared without applying a capacitor to each inverter and each converter element. Accordingly, the volume can be reduced, and a low-voltage capacitor can be applied, thereby reducing production costs.

[0078] Figure 4 is a schematic diagram illustrating a connection structure between a plurality of battery modules according to an exemplary embodiment of the present invention.

[0079] refer to Figure 4, the first battery module 10-1 and the second battery module 10-2 may include the same components and may have the same structure. In addition, the first battery module 10-1 and the second battery module 10-2 may include: batteries 110-1 and 110-2, inverters 120-1 and 120-2, first DC / DC converters 130-1 and 130-2, and second DC / DC converters 140-1 and 140-2. Alternatively, the first battery module 10-1 and the second battery module 10-2 may further include as shown in reference Figure 3 The shared capacitor.

[0080] In addition, a plurality of battery modules may be connected to each other to form a battery module system, and a connection relationship between each of the plurality of battery modules included in the battery module system may be the same as Figure 4 The structures shown are the same.

[0081] More specifically, the output terminal 120-1d of the inverter 120-1 included in the first battery module 10-1 can be connected in series to the output terminal 120-2c of the inverter 120-2 included in the second battery module 10-2. In addition, when the inverter outputs the AC module voltage, the inverter 120-1 included in the first battery module 10-1 and the inverter 120-2 included in the second battery module 10-2 can be connected in series with each other to output an AC module voltage with an amplitude twice that of the AC module voltage. For example, when the AC module voltage is set to 100V, the two inverters 120-1 and 120-2 connected in series with each other can output an AC voltage of 200V. In this case, the amplitude of the AC voltage can refer to the maximum value, effective value, or average value of the AC voltage.

[0082] In addition, the output end of the first DC / DC converter 130-1 included in the first battery module 10-1 and the output end of the first DC / DC converter 130-2 included in the second battery module 10-2 can be connected in parallel with each other. In an exemplary embodiment, one end 130-1d of the first DC / DC converter 130-1 included in the first battery module 10-1 can be grounded, and one output end 130-2d of the output end of the first DC / DC converter 130-2 included in the second battery module 10-2 can be grounded. In addition, another output end 130-1c of the output end of the first DC / DC converter 130-1 included in the first battery module 10-1 can be connected in parallel to another output end 130-2c of the output end of the first DC / DC converter 130-2 included in the second battery module 10-2 to output the first DC module voltage. In addition, among the output ends of the first DC / DC converter, another output end connected in parallel with each other can output the first DC module voltage, and can be connected to a low-voltage load using the first DC module voltage as a driving voltage to provide a voltage.

[0083] In addition, the output terminal of the second DC / DC converter 140-1 included in the first battery module 10-1 can be connected in series to the output terminal of the second DC / DC converter 140-2 included in the second battery module 10-2. More specifically, one output terminal 140-1d of the output terminals of the second DC / DC converter 140-1 included in the first battery module 10-1 can be connected to the other output terminal 140-2c of the output terminal of the second DC / DC converter 140-2 of the second battery module 10-2.

[0084] In addition, when the second DC / DC converters 140-1 and 140-2 output the second DC module voltage, the second DC / DC converter 140-1 included in the first battery module 10-1 and the second DC / DC converter 140-2 included in the second battery module 10-2 can be connected in series with each other to output a second DC module voltage having an amplitude twice that of the second DC module voltage. For example, when the second DC module voltage is set to 100V, the two second DC / DC converters 140-1 and 140-2 connected in series with each other can output 200V.

[0085] In other words, the first battery module 10 - 1 and the second battery module 10 - 2 may be connected to each other in series, the first DC / DC converters may be connected to each other in parallel, and the second DC / DC converters may be connected to each other in series.

[0086] In addition, the single-phase battery module system according to the exemplary embodiment of the present invention may include a plurality of battery modules 10-1, 10-2, ..., 10-N. In addition, each of the plurality of battery modules 10-1, 10-2, ..., 10-N included in the single-phase battery module system 100 may be connected to Figure 2 or Figure 3 The battery modules 10 and 20 shown in FIG. 1 are the same. In addition, the single-phase battery module system includes a plurality of battery modules 10-1, 10-2, ..., 10-N which may have Figure 4 The connection structure between the battery modules shown.

[0087] Return to reference Figure 2 According to an exemplary embodiment of the present invention, the battery module may include first DC module output terminals 130c and 130d corresponding to the output terminal of the first DC / DC converter 130, second DC module output terminals 140c and 140d corresponding to the output terminal of the second DC / DC converter 140, and AC module output terminals 120c and 120d corresponding to the output terminal of the inverter 120.

[0088] In addition, reference Figure 5, the single-phase battery module system 100 according to the exemplary embodiment of the present invention may include first DC system output terminals 130c and 130d, wherein the first DC module output terminals respectively included in the plurality of battery modules are connected in parallel with each other. In this case, the first DC system output terminals 130c and 130d may output a first DC system voltage, and the first DC system voltage may have the same amplitude as the amplitude of the first DC module voltage output from the output terminal of the first DC / DC converter.

[0089] In addition, the single-phase battery module system 100 according to the exemplary embodiment of the present invention may include second DC system output terminals 140-1c and 140-Nd, wherein the second DC module output terminals respectively included in the plurality of battery modules are connected in series with each other. Here, the second DC system output terminals 140-1c and 140-Nd may output a second DC system voltage, and the amplitude of the second DC system voltage may be an integer (N) times the amplitude of the second DC module voltage output from the output terminal of the second DC / DC converter.

[0090] In addition, the single-phase battery module system 100 according to the exemplary embodiment of the present invention may include AC system output terminals 120-1c and 120-Nd, wherein the AC module output terminals respectively included in the plurality of battery modules are connected in series with each other. In addition, the AC system output terminals 120-1c and 120-Nd may output an AC system voltage, and the amplitude of the AC system voltage may be an integer (N) times the amplitude of the AC module voltage output from the output terminal of the inverter. At the same time, the AC system output terminal may provide AC power to an AC load, and may provide an input voltage for one phase of a three-phase AC voltage.

[0091] In other words, in the single-phase battery module system 100 , respective elements of a plurality of battery modules may be connected to each other in series or in parallel to provide various output voltages including a first DC system voltage, a second DC system voltage, and an AC system voltage.

[0092] In addition, the electric vehicle may include a low voltage load operating at a low voltage, a high voltage load operating at a high voltage, and an AC load (e.g., a motor) operating at a high voltage three-phase AC voltage. In addition, the low voltage load may use a first DC system voltage as a driving voltage, the high voltage load may use a second DC system voltage as a driving voltage, and the AC load may use an AC system voltage as a driving voltage.

[0093] Figure 6 is a schematic diagram showing the connection relationship of the inverter in the three-phase battery module system 1000 according to an exemplary embodiment of the present invention. In addition, Figure 7 is a schematic diagram showing the connection relationship of the first DC / DC converter in the three-phase battery module system according to an exemplary embodiment of the present invention. In addition, Figure 8 is a schematic diagram illustrating a connection relationship of a second DC / DC converter in a three-phase battery module system according to an exemplary embodiment of the present invention.

[0094] refer to Figures 6 to 8 , the three-phase battery module system 1000 according to the exemplary embodiment of the present invention may include a plurality of single-phase battery module systems 100 - 1 , 100 - 2 , and 100 - 3 , and each single-phase battery module system may include a plurality of battery modules.

[0095] refer to Figure 6 According to an exemplary embodiment of the present invention, the three-phase battery module system 1000 may include three single-phase battery module systems 100-1, 100-2, and 100-3. In addition, the single-phase battery module system may include an AC system output terminal, wherein the inverter output terminals are connected in series with each other. In addition, the AC system output terminals respectively included in the three single-phase battery module systems may output different AC voltages having the same amplitude and the same phase difference.

[0096] For example, the AC system output terminals respectively included in the three single-phase battery module systems can output different AC voltages with a phase difference of 120 degrees. Therefore, the three-phase battery module system can output a three-phase AC voltage and can provide a driving voltage to an AC load (e.g., a motor) that uses the three-phase AC voltage as a driving voltage.

[0097] In addition, reference Figure 7 , each of the plurality of single-phase battery module systems 100-1, 100-2, and 100-3 included in the three-phase battery module system 1000 according to the exemplary embodiment of the present invention may include a first DC system output terminal, wherein the plurality of first DC / DC converters are connected in parallel to each other to output a first DC system voltage. In addition, the first DC system output terminals respectively included in the plurality of single-phase battery module systems 100-1, 100-2, and 100-3 may be connected in parallel to each other.

[0098] In other words, when the single-phase battery module system 100 includes N first DC / DC converters, all of the 3×N first DC / DC converters included in the three-phase battery module system 1000 can be connected in parallel to each other to output a first DC system voltage having the same amplitude as the first DC module voltage.

[0099] In addition, reference Figure 8, each of the multiple single-phase battery module systems 100-1, 100-2 and 100-3 included in the three-phase battery module system 1000 according to the exemplary embodiment of the present invention may include a second DC system output terminal, wherein the multiple second DC / DC converters are connected in series with each other to output a second DC system voltage. In addition, the second DC system output terminals respectively included in the multiple single-phase battery module systems 100-1, 100-2 and 100-3 can be connected in parallel with each other. That is, in the single-phase battery module system 100, the second DC module output terminals can be connected in series to form a second DC system output terminal. In the three-phase battery module system 1000, each of the multiple second DC system output terminals can be connected in parallel with each other.

[0100] In the above Figures 4 to 8 In FIG. 1 , the (-) terminals of the first DC / DC converters are shown as being combined and grounded, but the (-) terminals of the first DC / DC converters may be simply combined into one.

[0101] In addition, the three-phase battery module system may further include a controller (not shown). The controller may control each battery module individually, and may control the inverter, the first DC / DC converter, and the second DC / DC converter included in each battery module individually. Accordingly, according to an exemplary embodiment of the present invention, balancing control may be performed on each power conversion element and each battery module, thereby improving energy efficiency.

[0102] Furthermore, when a problem occurs in one of the N battery modules, the controller may perform control to disconnect only the battery module in which the problem occurs, thereby ensuring the reliability of the entire system.

[0103] In addition, the controller can control each battery module individually. Accordingly, even when each battery module has different degrees of performance degradation, the degraded performance of each battery module can be actively controlled.

[0104] at the same time, Fig. 9 is a schematic diagram showing a structure of an inverter according to an exemplary embodiment of the present invention.

[0105] The inverter 120 may include an upper switch 1201 and a lower switch 1202 disposed in the first branch Lg1 and connected in series, and an upper switch 1203 and a lower switch 1204 disposed in the second branch Lg2 and connected in series. Here, one output terminal 120c of the output terminals 120c and 120d of the inverter 120 may be between the upper switch 1201 and the lower switch 1202 of the first branch Lg1, and the other output terminal 120d of the output terminals 120c and 120d of the inverter 120 may be between the upper switch 1203 and the lower switch 1204 of the second branch Lg2.

[0106] refer to Fig. 9 The inverter 120 may include a plurality of power semiconductor devices, for example, Si-MOSFET (Metal Oxide Semiconductor Field Effect Transistor, MOSFET) elements 1201 , 1202 , 1203 , and 1204 , and may be formed into an H-bridge single-phase inverter structure.

[0107] In conventional electric vehicle systems, SiC power semiconductors are mainly used. Such SiC power semiconductors have high efficiency and fast switching speed, but are expensive.

[0108] Additionally, conventional electric vehicle systems sometimes use insulated gate bipolar transistors (IGBTs) at low voltages, and while IGBTs are relatively inexpensive, IGBTs can have slow switching speeds.

[0109] On the other hand, the Si-MOSFET element may have a fast switching speed and may be relatively inexpensive, but its performance may deteriorate under high voltage, so it may be difficult to apply the Si-MOSFET element to a conventional high-voltage electric vehicle system.

[0110] Since the battery module according to the exemplary embodiment of the present invention is driven at a low voltage, the Si-MOSFET element can be applied to the inverter. Accordingly, the inverter included in the battery module according to the exemplary embodiment of the present invention can use a plurality of Si-MOSFET elements, thereby reducing production costs and having a fast switching speed. Accordingly, the power efficiency can be improved, so that the driving distance of the vehicle can be increased, and as the driving distance increases, the battery capacity can be reduced to reduce production costs.

[0111] Furthermore, the inverter according to the exemplary embodiment of the present invention may be configured with an H-bridge single-phase inverter structure and may maintain stability even at a high current.

[0112] also, Fig. 9 The case where the H-bridge circuit is formed using four Si-MOSFETs is shown as an example. However, the H-bridge circuit can also be formed by connecting a plurality of Si-MOSFETs in parallel to each other, thereby realizing switching of a high current.

[0113] at the same time, Fig.10 is a configuration diagram of a vehicle according to an exemplary embodiment of the present invention.

[0114] like Fig.10As shown, a vehicle according to an exemplary embodiment of the present invention may include a plurality of single-phase battery module systems 100-1, 100-2 and 100-3, a control module 100-4 and an inductor module 420, the inductor module 420 including a plurality of inductors La, Lb and Lc connected to each of the plurality of single-phase battery module systems 100-1, 100-2 and 100-3.

[0115] First, the plurality of single-phase battery module systems 100 - 1 , 100 - 2 , and 100 - 3 may include a plurality of battery modules provided for each phase of a motor.

[0116] For example, in the case of phase A of the motor, the single-phase battery module system 100-1 may include a plurality of battery modules 10-1, 10-2, and 10-N, each of which may include: batteries 110-1, 110-2, and 110-N, inverters 120-1, 120-2, and 120-N, first DC / DC converters 130-1, 130-2, and 130-N, and second DC / DC converters 140-1, 140-2, and 140-N. Here, the input terminals of the batteries 110-1, 110-2, and 110-N and the inverters 120-1, 120-2, and 120-N may be connected in parallel, and the output terminals of the inverters 120-1, 120-2, and 120-N may be connected in series to the output terminals of the inverters included in the adjacent battery modules.

[0117] Although not separately illustrated for simplicity of the present invention, each of the single-phase battery module systems 100 - 2 and 100 - 3 of the other phases (B phase and C phase) of the motor may also have the same configuration.

[0118] Furthermore, the number of battery modules included in any one of the plurality of single-phase battery module systems 100 - 1 , 100 - 2 , and 100 - 3 may be the same as the number of battery modules included in another one of the plurality of single-phase battery module systems.

[0119] In addition, another output end of the output end of the inverter included in one of the multiple battery modules included in one single-phase battery module system among the multiple single-phase battery module systems 100-1, 100-2 and 100-3 can be interconnected with another output end of the output end of the inverter included in one of the multiple battery modules included in any other single-phase battery module system among the multiple single-phase battery module systems 100-1, 100-2 and 100-3 and can be connected to the AC power source 2.

[0120] For example, one of the multiple battery modules 10-1, 10-2 and 10-N included in the single-phase battery module system 100-1, for example, another output terminal 120-Nd among the output terminals of the inverter 120-N included in the battery module 10-N arranged at the lowest end can be interconnected with one of the multiple battery modules included in another single-phase battery module system 100-2 and 100-3, for example, another output terminal 120-Nd among the output terminals of the inverter included in the battery module arranged at the lowest end, and can be connected to the AC power source 2.

[0121] That is, the single-phase battery module systems 100 - 1 , 100 - 2 , and 100 - 3 may be interconnected at a connection point 411 , and a lower switch 421 may be further included between the connection point 411 and the AC power source 2 .

[0122] Meanwhile, the inductor module 420 may include a plurality of inductors La, Lb, and Lc, and each of the plurality of inductors La, Lb, Lc may be connected to each of the plurality of single-phase battery module systems.

[0123] The inductors La, Lb, and Lc may be a kind of filter for preventing a sudden change in current flowing into the battery.

[0124] According to an exemplary embodiment of the present invention, the above-mentioned inductors La, Lb, and Lc may be separately provided inductors, which are not stator windings of the motor.

[0125] Specifically, one end of each of the multiple inductors La, Lb and Lc can be interconnected (see 412) and connected to the AC power source 2, and the other end of each of the multiple inductors La, Lb, Lc can be connected to each of the multiple single-phase battery module systems 100-1, 100-2 and 100-3.

[0126] In addition, the other end of each of the multiple inductors La, Lb and Lc can be connected to one of the multiple battery modules included in each of the multiple single-phase battery module systems 100-1, 100-2 and 100-3, for example, one of the output ends of the single-phase inverter included in the battery module arranged at the uppermost end.

[0127] For example, in the case of phase A of the motor, the other end of the inductor La can be connected to one of the battery modules 10-1, 10-2 and 10-N included in the single-phase battery module system 100-1, for example, one output terminal 120-1c of the output terminal of the inverter 120-1 included in the battery module 10-1 arranged at the uppermost end. The same connection method as described above can be applied to other single-phase battery module systems 100-2 and 100-3.

[0128] In addition, according to the exemplary embodiment of the present invention, a plurality of upper switches Sa, Sb, and Sc may be further included between one end of each of the other ends of the plurality of inductors La, Lb, and Lc and each of the plurality of single-phase battery module systems 100-1, 100-2, and 100-3.

[0129] Meanwhile, according to an exemplary embodiment of the present invention, an upper switch 422 may be further included between the inductor module 420 and the AC power source 2 .

[0130] Meanwhile, the control module 100 - 4 may include a controller C and a memory M, and may control an inverter and other switches through a switching signal.

[0131] When AC charging is performed, that is, when a charging signal for AC charging is received from the AC power source 2, the controller C may receive an AC voltage from the AC power source 2 through a plurality of inductors La, Lb, and Lc, and may control the inverter to charge the battery.

[0132] Specifically, when the polarity of the AC power supply is positive (+), the controller C can turn on the upper switch of the first branch and the lower switch of the second branch; when the polarity of the AC power supply is negative (-), the controller C can turn on the lower switch of the first branch and the upper switch of the second branch.

[0133] In this case, according to the duty ratio of the turned-on switch, the charging amount of the battery charging can be controlled based on the amount of current flowing through the plurality of inductors.

[0134] According to an exemplary embodiment of the present invention, the controller C can control the inverter of each single-phase battery module system in the plurality of single-phase battery module systems. For example, the controller C can equally control all of the plurality of single-phase battery module systems through the control of the inverter, or can control each single-phase battery module system in the plurality of single-phase battery module systems.

[0135] The control module 100-4 may include a processor (e.g., a computer, a microprocessor, a CPU, an ASIC, a logic circuit, etc.) and a memory that stores software instructions that provide various functions when executed by the processor. Here, the processor and the memory may be implemented as separate semiconductor circuits. Alternatively, the processor and the memory may be implemented as a single integrated semiconductor circuit. There may be one or more processors.

[0136] at the same time, Fig.11 and Fig.12 is a schematic diagram showing a charging path according to the polarity of the AC power source. Fig.11 2 shows the charging path when the polarity of the AC power source 2 is positive (+), Fig.12Hereinafter, the single-phase battery module system 100-1 is described, but the same description of the single-phase battery module system 100-1 can be applied to other single-phase battery module systems 100-2 and 100-3.

[0137] Specifically, according to an exemplary embodiment of the present invention, Figures 9 to 11 As shown, when the polarity of the AC power source 2 is positive (+), the upper switch 1201 of the first branch Lg1 and the lower switch 1204 of the second branch Lg2 of the inverters 120-1, 120-2 and 120-N can be turned on, and the lower switch 1202 of the first branch Lg1 and the upper switch 1203 of the second branch Lg2 can be turned off. Accordingly, the batteries 110-1, 110-2 and 110-N respectively included in the battery module system 100-1 can be connected as shown in FIG. Fig.11 The charging is performed along the path shown (see the thick solid line).

[0138] In this case, the charging amount of each of the batteries 110-1, 110-2, and 110-N can be controlled based on the amount of current flowing through the inductor La according to the duty ratio of the turned-on switch. That is, the inverter is configured to receive an AC voltage from an AC power source through a plurality of inductors La, Lb, and Lc during charging, and can charge the battery.

[0139] On the other hand, Fig. 9 , Fig.10 and Fig.12 As shown, when the polarity of the AC power source 2 is negative (-), the lower switch 1202 of the first branch Lg1 and the upper switch 1203 of the second branch Lg2 of the inverters 120-1, 120-2 and 120-N can be turned on, and the upper switch 1201 of the first branch Lg1 and the lower switch 1204 of the second branch Lg2 can be turned off.

[0140] Accordingly, the batteries 110-1, 110-2 and 110-N respectively included in the battery module system 100-1 can be Fig.12 In this case, the charging amount of each of the batteries 110-1, 110-2, and 110-N can be controlled based on the amount of current flowing through the inductor La according to the duty ratio of the turned-on switch.

[0141] In addition, the switches 1201 to 1204 included in the inverters 120-1, 120-2, and 120-N may be switched according to the frequency and phase of the AC power source 2. A phase locked loop (PLL) may be used for this purpose.

[0142] at the same time, Fig.13is a flowchart illustrating a charging control method of a vehicle according to an exemplary embodiment of the present invention.

[0143] refer to Fig.13 The charging control method ( S1300 ) of the vehicle according to the exemplary embodiment of the present invention may be started by the step ( S1301 ) in which the control module 100 - 4 receives a charging signal for AC charging from the charger 2 .

[0144] Then, the control module 100 - 4 may receive an AC voltage from the AC power source 2 through the plurality of inductors La, Lb, and Lc, and may control the inverter to charge the battery ( S1302 ).

[0145] Specifically, when the polarity of the AC power source is positive (+), the control module 100-4 can turn on the upper switch of the first branch and the lower switch of the second branch, and when the polarity of the AC power source is negative (-), the control module 100-4 can turn on the lower switch of the first branch and the upper switch of the second branch. In this case, according to the duty cycle of the turned-on switch, the charging amount of the battery can be controlled based on the amount of current flowing through the plurality of inductors La, Lb, and Lc.

[0146] In this way, according to an exemplary embodiment of the present invention, the motor can be driven by multiple low-voltage battery modules, which are configured to integrate batteries and inverters into a single module for each phase of the motor, but during the charging process, the battery can be charged using the inverter, so there is no need to install a separate vehicle charger, thereby reducing the cost of the charger and reducing the overall volume.

[0147] In addition, according to an exemplary embodiment of the present invention, the output and capacity of the inverter can be freely increased by combining multiple battery modules in series or in parallel, so that fast charging can be performed compared to existing on-board chargers with limited capacity (e.g., 3kW to 10kW).

[0148] at last, Fig.14 is a block diagram of a computing device that can fully or partially implement the control module 100 - 4 according to an exemplary embodiment of the present invention.

[0149] like Fig.14 As shown, computing device 1400 includes at least one processor 1401 , a computer-readable storage medium 1402 , and a communication bus 1403 .

[0150] The processor 1401 may cause the computing device 1400 to operate according to the exemplary embodiments described above. For example, the processor 1401 may execute one or more programs stored on the computer-readable storage medium 1402. The one or more programs may include one or more computer-executable instructions, and the computer-executable instructions may be configured to cause the computing device 1400 to perform operations according to the exemplary embodiments when executed by the processor 1401.

[0151] The computer-readable storage medium 1402 is configured to store computer-executable instructions, program codes, program data, and / or other appropriate information. The program 1402a stored on the computer-readable storage medium 1402 includes a set of instructions that can be executed by the processor 1401. In an exemplary embodiment, the computer-readable storage medium 1402 can be a memory (e.g., a volatile memory such as a random access memory, a non-volatile memory, or a suitable combination thereof), one or more magnetic disk storage devices, optical disk storage devices, flash memory devices, or any other form of storage medium or a suitable combination thereof that is accessed by the computing device 1400 and capable of storing the required information.

[0152] The communication bus 1403 interconnects various other components of the computing device 1400 including the processor 1401 and the computer-readable storage medium 1402 .

[0153] The computing device 1400 may also include one or more input / output interfaces 1405 that provide an interface for one or more input / output devices 1404, and one or more network communication interfaces 1406. The input / output interface 1405 and the network communication interface 1406 are connected to the communication bus 1403. The network may be a cellular network, such as Global System for Mobile Communications (GSM), Enhanced Data Rates for GSM Evolution (EDGE), General Packet Radio Service (GPRS), Code Division Multiple Access (CDMA), Time Division CDMA (TD-CDMA), Universal Mobile Telecommunications System (UMTS), Long Term Evolution (LTE), or another cellular network.

[0154] The input / output device 1404 may be connected to other components of the computing device 1400 through the input / output interface 1405. Examples of the input / output device 1404 may include: an input device and / or an output device, the input device, for example, a pointing device (e.g., a mouse or trackpad), a keyboard, a touch input device (e.g., a touchpad or touch screen), a voice or sound input device, various types of sensor devices, and / or a photographic device; the output device, for example, a display device, a printer, a speaker, and / or a network card. The exemplary input / output device 1404 may be included in the computing device 1400 as a component forming the computing device 1400, or may be connected to the computing device 1400 as a separate device different from the computing device 1400.

[0155] Meanwhile, exemplary embodiments of the present invention may include a program for executing the method described herein on a computer, and a computer-readable recording medium including the program. Computer-readable recording medium may include program commands, local data files, local data structures, etc., individually or in combination. Medium may be a medium designed and configured specifically for the present invention, or may be a medium common in the field of computer software. The example of computer-readable recording medium includes magnetic media (e.g., hard disk, floppy disk and tape), optical recording media (e.g., CD-ROM and DVD), and hardware devices (e.g., ROM, RAM and flash memory) specifically configured to store and execute program commands. The example of program may include, for example, machine language code generated by a compiler, and high-level language code that can be executed by a computer utilizing an interpreter, etc.

[0156] Although the representative exemplary embodiments of the present invention have been described in detail above, it will be appreciated by those skilled in the art that the above embodiments may be modified in various ways without departing from the scope of the present invention. Therefore, the scope of the present invention should not be limited to the exemplary embodiments described, but should be determined by the claims described and claims equivalent to the claims.

Claims

1. A vehicle comprising: a plurality of single-phase battery module systems, the plurality of single-phase battery module systems comprising a plurality of battery modules and provided for each phase of the motor, wherein each of the battery modules comprises a battery and a power conversion module, each power conversion module comprising an inverter configured to convert a DC voltage stored in the battery into an AC voltage to control the motor; and a plurality of inductors connected to each of the plurality of single-phase battery module systems; Each inverter is configured to receive an AC voltage from an AC power source through a plurality of inductors and charge the battery during charging.

2. The vehicle according to claim 1, wherein: The input terminal of the inverter is connected in parallel with the battery. The output terminal of the inverter is connected in series to the output terminal of the inverter included in the adjacent battery module.

3. The vehicle according to claim 1, wherein: One end of each of the plurality of inductors is connected to each other and to an AC power source, The other end of each of the plurality of inductors is connected to a plurality of single-phase battery module systems.

4. The vehicle according to claim 3, wherein: The other end of each of the plurality of inductors is connected to one of the output ends of an inverter included in one of the plurality of battery modules included in each of the plurality of single-phase battery module systems.

5. The vehicle according to claim 4, wherein: Another output end of the output end of the inverter included in one of the battery modules included in any one of the multiple single-phase battery module systems is connected to another output end of the output end of the inverter included in one of the multiple battery modules included in another single-phase battery module system among the multiple single-phase battery module systems and is connected to an AC power supply.

6. The vehicle according to claim 5, wherein: Each inverter includes: A first upper switch and a first lower switch, the first upper switch and the first lower switch are arranged in the first branch and connected in series; and a second upper switch and a second lower switch, the second upper switch and the second lower switch being arranged in the second branch and connected in series; wherein one of the output terminals of the inverter is between the first upper switch and the first lower switch; Another one of the output terminals of the inverter is between the second upper switch and the second lower switch.

7. The vehicle according to claim 1, wherein: The number of battery modules included in a first single-phase battery module system among the plurality of single-phase battery module systems is the same as the number of battery modules included in a second single-phase battery module system among the plurality of single-phase battery module systems.

8. The vehicle of claim 1, wherein: Each inverter includes an H-bridge single-phase inverter provided with a plurality of power semiconductor elements.

9. The vehicle according to claim 6, wherein: When the polarity of the AC power source is positive, the first upper switch and the second lower switch are turned on. When the polarity of the AC power source is negative, the first lower switch and the second upper switch are turned on to charge the battery.

10. The vehicle of claim 1, wherein: According to the duty ratio of the turned-on switch, the charging amount of the battery is controlled based on the amount of current flowing through the inductor.

11. The vehicle according to claim 5, wherein: The inverter includes a switch that performs switching according to the frequency and phase of the AC power source.

12. The vehicle of claim 1, wherein: The inductor is a separately provided inductor, not a stator winding of the motor.

13. The vehicle of claim 1, further comprising: A plurality of upper switches are disposed between each of the plurality of inductors and each of the plurality of single-phase battery module systems.

14. A charging control method for a vehicle, the vehicle comprising a plurality of single-phase battery module systems having a plurality of battery modules and provided for each phase of a motor, and a plurality of inductors, wherein each of the battery modules comprises a battery and a power conversion module, each power conversion module comprises an inverter configured to convert a DC voltage stored in the battery into an AC voltage to control the motor, the plurality of inductors being connected to each of the plurality of single-phase battery module systems, the method comprising: a receiving step, in which a charging signal for AC charging is received from a charger; A control step, when a charging signal is received, receives an AC voltage from an AC power source through a plurality of inductors and controls an inverter to charge the battery in the control step.

15. The vehicle charging control method according to claim 14, wherein: Each inverter includes a first upper switch and a first lower switch disposed in a first branch and connected in series, and a second upper switch and a second lower switch disposed in a second branch and connected in series; In the control step, when the polarity of the AC power source is positive, the first upper switch and the second lower switch are turned on, and when the polarity of the AC power source is negative, the first lower switch and the second upper switch are turned on.

16. The vehicle charging control method according to claim 14, wherein: In the control step, the charge amount of the battery is controlled based on the amount of current flowing through the inductor according to the duty ratio of the turned-on switch.

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