Vehicle battery module including power conversion device and vehicle battery system configured on basis of plurality of vehicle battery modules

Abstract

The present invention relates to a vehicle battery module including a power conversion device, and a vehicle battery system configured on the basis of a plurality of vehicle battery modules. More specifically, the vehicle battery module includes: a battery outputting a battery voltage; a DC / DC converter converting the battery voltage into a DC module voltage less than the battery voltage and outputting the DC module voltage; and an inverter unit converting the battery voltage into an alternating-current (AC) module voltage and outputting the AC module voltage. The inverter unit includes: a first inverter converting the battery voltage into a primary AC voltage; a transformer converting the primary AC voltage into a secondary AC voltage; a rectifier converting the secondary AC voltage into a DC voltage; a capacitor connected in parallel to an output end of the rectifier; and a second inverter converting a voltage of the capacitor into the AC module voltage.

Description

A vehicle battery module including a power conversion device and a vehicle battery system configured based on a plurality of vehicle battery modules.

[0001] The present invention relates to a vehicle battery module including a power conversion device, and a vehicle battery system configured based on a plurality of vehicle battery modules.

[0002] Today, with growing interest in issues such as energy efficiency, environmental pollution, and fossil fuel depletion, the development of eco-friendly vehicles that can practically replace internal combustion engine vehicles is actively underway.

[0003] Eco-friendly vehicles include battery electric vehicles (BEVs) that use batteries as a power source, fuel cell electric vehicles (FCEVs) that use fuel cells as their main power source, and hybrid electric vehicles (HEVs) that use both an engine and a motor as a driving force.

[0004] The above-mentioned eco-friendly vehicles can be broadly called electric vehicles (xEVs), and have in common the characteristics of being motor-driven vehicles and electrified vehicles that run by driving a motor with electricity from a high-voltage power source such as a battery or fuel cell.

[0005] Electric vehicles are equipped with high-voltage batteries that power the motor. These batteries charge and discharge repeatedly during vehicle operation, powering the motor and other power electronics within the vehicle. Since each type of power electronics component requires a variety of voltage levels and types, various power conversion devices are required to convert the output voltage of the high-voltage battery. These power conversion devices must convert the high voltage output from the high-voltage battery, requiring high-voltage power conversion elements. Their high cost can increase production costs.

[0006] (Patent Document 1) KR 10-2532333 B1

[0007] The present invention aims to enable the use of power conversion elements capable of operating at low voltage by enabling a conventional electric vehicle driving system, which operates at high voltage, to be configured by a series / parallel combination of a plurality of battery modules operating at low voltage.

[0008] And the present invention aims to configure a battery system by connecting standardized battery modules in series / parallel, thereby outputting voltages of various sizes according to the purpose and responding to various specifications required for each vehicle type.

[0009] The purpose of the present invention is not limited to the tasks mentioned above, and other tasks not mentioned can be clearly understood by those of ordinary skill in the art from the description below.

[0010] In order to achieve the above-mentioned purpose, the present invention provides a vehicle battery module, a vehicle single-phase battery system configured based on the vehicle battery module, and a vehicle three-phase battery system.

[0011] A vehicle battery module according to one embodiment of the present invention includes a battery that outputs a battery voltage, a DC / DC converter that converts the battery voltage into a DC module voltage lower than the battery voltage and outputs the converted battery voltage, and an inverter unit that converts the battery voltage into an AC module voltage and outputs the converted battery voltage, wherein the inverter unit includes a first inverter that converts the battery voltage into a primary AC voltage, a transformer that converts the primary AC voltage into a secondary AC voltage, a rectifier that converts the secondary AC voltage into a DC voltage, a capacitor that is connected in parallel to an output terminal of the rectifier, and a second inverter that converts the voltage of the capacitor into the AC module voltage.

[0012] And, according to one embodiment of the present invention, a single-phase battery system for a vehicle includes a plurality of vehicle battery modules including a DC module output terminal that outputs a DC module voltage lower than the battery voltage from an internal battery voltage, and an AC module output terminal that outputs an AC module voltage, a DC system output terminal configured by connecting the DC module output terminals included in each of the plurality of vehicle battery modules in parallel, and an AC system output terminal configured by connecting the AC module output terminals included in each of the plurality of vehicle battery modules in series.

[0013] And, according to one embodiment of the present invention, a vehicle three-phase battery system is configured based on a plurality of vehicle battery modules including a DC module output terminal that outputs a DC module voltage lower than the battery voltage from the internal battery voltage, and an AC module output terminal that outputs an AC module voltage, and includes a plurality of vehicle single-phase battery systems including a DC system output terminal configured by connecting the DC module output terminals included in each of the plurality of vehicle battery modules in parallel, and an AC system output terminal configured by connecting the AC module output terminals included in each of the plurality of vehicle battery modules in series, and the AC system output terminals included in each of the plurality of vehicle single-phase battery systems output different AC system voltages having the same magnitude and the same phase difference.

[0014] According to one embodiment of the present invention, a standardized battery module that operates at low voltage can be used to apply a power conversion element capable of operating at low voltage, thereby reducing the manufacturing cost.

[0015] In addition, even if the required voltage or specifications are different for each vehicle model, standardized battery modules can be combined in series and parallel to meet various specifications, and mass production is possible, so production costs can be reduced.

[0016] In addition, according to one embodiment of the present invention, by configuring a battery module system by connecting standardized battery modules in series / parallel, space utilization efficiency can be increased, so that the overall volume can be reduced. In addition, in case of a malfunction in some parts, each battery module can be replaced, so that repairs are easy. In addition, since balancing control can be performed for each battery module, the overall energy efficiency can be increased.

[0017] Figure 1 illustrates an electric vehicle drive system including a typical high-voltage battery pack.

[0018] Figures 2 to 4 illustrate a battery module according to one embodiment of the present invention.

[0019] FIG. 5 is a drawing for explaining a connection structure between a plurality of battery modules according to one embodiment of the present invention.

[0020] Figure 6 illustrates a single-phase battery system according to one embodiment of the present invention.

[0021] Figure 7 illustrates a three-phase battery system according to one embodiment of the present invention.

[0022] FIG. 8 is a block diagram illustrating a battery module and a single-phase battery system for a vehicle according to one embodiment of the present invention.

[0023] FIG. 9 is a block diagram illustrating an inverter unit according to one embodiment of the present invention.

[0024] FIG. 10 is a drawing for explaining the structure of an inverter according to one embodiment of the present invention.

[0025] Hereinafter, specific embodiments of the present invention will be described with reference to the drawings. The following detailed description is provided to facilitate a comprehensive understanding of the methods, devices, and / or systems described herein. However, these are merely examples and the present invention is not limited thereto.

[0026] In describing embodiments of the present invention, if a detailed description of a known technology related to the present invention is judged to unnecessarily obscure the gist of the present invention, the detailed description will be omitted. In addition, the terms described below are terms defined in consideration of their functions in the present invention, and this may vary depending on the intention or custom of the user or operator. Therefore, the definitions should be made based on the contents throughout this specification. The terminology used in the detailed description is only for the purpose of describing embodiments of the present invention and should not be limited in any way. Unless clearly used otherwise, the singular form includes the plural form. In this description, expressions such as "comprises" or "having" are intended to indicate certain features, numbers, steps, operations, elements, parts or combinations thereof, and should not be construed to exclude the presence or possibility of one or more other features, numbers, steps, operations, elements, parts or combinations thereof other than those described.

[0027] Additionally, the 'module voltage' described below may mean the voltage output from the battery module, and the 'system voltage' may mean the voltage output from the battery system configured based on the battery module.

[0028] The battery module described below may include a vehicle battery module, and the battery system may include a vehicle single-phase battery system and a vehicle three-phase battery system.

[0029] And, of course, the present invention can be used not only in vehicles but also in various devices to which battery modules and battery systems can be applied.

[0030]

[0031] Figure 1 illustrates an electric vehicle drive system including a typical high-voltage battery pack.

[0032] Referring to FIG. 1, the electric vehicle driving system (1) may include a general high-voltage battery pack (11) and various power conversion devices (12).

[0033] At this time, a typical high-voltage battery pack (11) is configured by a series / parallel combination of multiple battery cells and may not include a separate power conversion device. In addition, a typical high-voltage battery pack (11) can output a single-sized high voltage (e.g., 480 V to 806.4 V). In addition, a power conversion device (12) may be provided in a separate space separate from the high-voltage battery pack (11), and the high-voltage battery pack (11) and the power conversion device (12) may be connected by a high-voltage cable.

[0034] Meanwhile, electric vehicles have electrical loads with various functions, and since the voltages required for each electrical load vary in size and type, various types of power conversion devices (12) are required. However, according to an electric vehicle drive system (1) including a general high-voltage battery pack (11), a high-voltage power conversion device (12) must be used because it is based on a single high voltage.

[0035] More specifically, the electric vehicle drive system (1) converts the high voltage output from a typical high-voltage battery pack (11) into a low-voltage DC voltage to provide a driving voltage to a low-voltage load (R1) or to charge a low-voltage battery. In this case, energy loss may occur during the process of converting power from high voltage to low voltage, reducing efficiency. Furthermore, since the voltage must be significantly lowered, a separate transformer may be additionally required.

[0036] And the electric vehicle drive system (1) can convert the voltage output from a general high-voltage battery pack (11) to provide a driving voltage to a high-voltage load (R2), and can form a high-voltage three-phase AC power source to provide a driving voltage to a motor (M). At this time, an inverter operating at high voltage generally uses SiC power semiconductors for high-voltage switching, but SiC power semiconductors have a low yield compared to high demand, making it difficult to smoothly supply and demand them, and their high price can increase production costs.

[0037] In addition, the electric vehicle drive system (1) has a structure in which the high-voltage battery pack (11) and the power conversion devices are each separated, so each component occupies a separate space, and a high-voltage cable must be used to connect them, which can take up a lot of space.

[0038] In addition, the electric vehicle drive system (1) may generate a lot of heat due to the high voltage output of the high voltage battery pack (11), and may be bulky and heavy due to the need for a water cooling system to control the heat generation.

[0039] And according to the electric vehicle drive system (1), since the specifications are different depending on the vehicle type, the battery system must be individually designed according to the specifications of the vehicle type, which may complicate the process and increase production costs.

[0040]

[0041] A battery system according to an embodiment of the present invention described below may be configured by a series / parallel combination of a plurality of battery modules, and each battery module may include a power conversion device operating at low voltage.

[0042] To reiterate, a battery system according to one embodiment of the present invention is configured based on battery modules, each of which includes a power conversion device operating at low voltage, thereby enabling not only the storage / release of electrical energy but also the conversion of power within the battery module. Accordingly, a battery module according to one embodiment of the present invention can convert direct current power into alternating current power or output the converted battery power by changing its size as needed.

[0043] In addition, the outputs of each battery module can be connected in series to form a high-voltage output or connected in parallel to form a high-current output, and the voltage of each battery module can be monitored to perform balancing control.

[0044] Hereinafter, a battery module and a battery system including the same according to one embodiment of the present invention will be described in more detail.

[0045]

[0046] Figure 2 illustrates a battery module according to one embodiment of the present invention.

[0047] Referring to FIG. 2, a battery module (10) according to one embodiment of the present invention may include a battery (110), a DC / DC converter (120), and an inverter unit (130). The inverter unit (130) may include a first inverter (131), a transformer (132), a rectifier (133), a capacitor (134), and a second inverter (135).

[0048] The battery (110) can output battery voltage and charge or discharge electric energy. The battery voltage constitutes the base voltage of the battery module (10), and can provide input voltage to the DC / DC converter (120) and the inverter unit (130).

[0049] In addition, the battery (110) may have a battery voltage lower than that of the general high-voltage battery pack (11) described in FIG. 1. Therefore, the vehicle battery module (10) according to one embodiment of the present invention can apply a power conversion element capable of operating at low voltage, thereby reducing the manufacturing cost.

[0050] And according to the battery module (10) according to one embodiment of the present invention, since it is possible to output voltages of various sizes and types depending on the series / parallel combination of the battery module (10), it is possible to apply the battery module (10) of a single standard to vehicle models of various standards, and manufacturing costs can be reduced.

[0051] In addition, a single-phase battery system that outputs a high-voltage AC system voltage can be configured by connecting the AC module voltages of the battery modules (10) in series, and a three-phase AC voltage can be output using a plurality of single-phase battery systems. In addition, a battery system in which a large current flows can be formed by combining the battery modules (10) in parallel.

[0052] And the DC / DC converter (120) can convert the battery voltage into a DC module voltage that is lower than the battery voltage and output it.

[0053] The DC module voltage can be set to the driving voltage of a low-voltage load for a vehicle. For example, the low-voltage load can be an electric load such as various lamps, radios, and infotainment systems in an electric vehicle. The first DC module voltage can be set to a driving voltage of a low-voltage load, such as 12 V, 24 V, or 48 V. However, the voltage magnitudes mentioned in this specification are merely exemplary and may be set to various voltage magnitudes depending on the design.

[0054] And the DC / DC converter can include an input terminal (120a, 120b) and an output terminal (120c, 120d), and the input terminal (120a, 120b) of the DC / DC converter can be connected in parallel to a battery to receive a battery voltage, and the output terminal (120c, 120d) of the DC / DC converter can output a DC module voltage. And hereinafter, the DC / DC converter output terminal (120c, 120d) may also be referred to as a DC module output terminal that outputs a DC module voltage.

[0055] Additionally, the output terminal (120c, 120d) of the DC / DC converter can be directly connected to a low-voltage load to provide a DC module voltage.

[0056] In one embodiment, one end (120d) of the output terminal of the DC / DC converter may be grounded, and the other end (120c) may be connected to a low-voltage load to output a DC module voltage. In another embodiment, both ends of the output terminal of the DC / DC converter may be connected to both ends of a low-voltage load to output a DC module voltage.

[0057]

[0058] The inverter unit (130) can convert the battery voltage into an AC module voltage and output it. The inverter unit (130) can include an input terminal and an output terminal, and the inverter unit input terminal can be connected in parallel to the battery to input the battery voltage, and the inverter unit output terminal can output the AC module voltage. In addition, the inverter unit output terminal may be referred to as an AC module output terminal that outputs the AC module voltage hereinafter. The inverter unit (130) can be configured to supply AC power according to the AC module voltage to the AC load. The inverter unit (130) can be connected in series with an inverter unit included in another battery module to supply AC power to the AC load. In this case, the AC load can be a load such as a motor that uses the AC voltage as a driving voltage.

[0059] More specifically, the inverter unit (130) may include a first inverter (131), a transformer (132), a rectifier (133), a capacitor (134), and a second inverter (135).

[0060] The first inverter (131) can convert the battery voltage into a primary AC voltage. In addition, the first inverter (131) can convert the battery voltage into an AC voltage having a frequency suitable for input to the transformer (132). In addition, the input terminals (131a, 131b) of the first inverter can be referred to as input terminals of the inverter unit and can be connected in parallel to the battery to receive the battery voltage.

[0061] And the transformer (132) can convert the primary AC voltage into a secondary AC voltage. The primary AC voltage may refer to the primary side voltage of the transformer, and the secondary AC voltage may refer to the secondary side voltage of the transformer. In addition, the transformer (132) may have a transformation ratio of 1:N, and preferably, a transformation ratio of 1:3. If the magnitude of the primary AC voltage is 50V and the transformation ratio is 1:3, the magnitude of the secondary AC voltage may be 150V.

[0062] In addition, the rectifier (133) can convert the secondary AC voltage into a DC voltage, and can perform the function of converting a half cycle or a full cycle of the AC voltage into a DC voltage. In addition, the capacitor (134) can be connected in parallel to the output terminal of the rectifier (133), and the DC voltage output from the rectifier (133) and the voltage across both terminals of the capacitor (134) can be the same.

[0063] And the first inverter (131) and rectifier (133) may be configured in the form of an H-bridge as shown in Fig. 10, and may have a structure in which diodes are connected in parallel to each of the four switches.

[0064] When the motor is driven, the first inverter (131) can convert the battery voltage into an AC module voltage, and the rectifier (133) can convert the AC voltage into a DC voltage. On the other hand, during regeneration, the rectifier (133) can perform the function of an inverter, and the first inverter (131) can perform the function of a rectifier.

[0065] In this way, the first inverter (131) and rectifier (133) can perform the role of an inverter or a rectifier depending on whether the motor is driven or regenerated, and this can be implemented using diodes connected in parallel in the form of an H-bridge as shown in FIG. 10.

[0066] In addition, the second inverter (135) can convert the voltage across both ends of the capacitor (134), i.e., the DC voltage output from the rectifier (133), into an AC module voltage and output it. The output terminals (135c, 135d) of the second inverter may be referred to as output terminals of the inverter unit and may constitute an AC module output terminal that outputs the AC module voltage. In addition, the second inverter (135) can convert the DC voltage to have a frequency suitable for the input of an AC load (e.g., a motor). In addition, during regeneration, the second inverter (135) can generate a current that controls the amount of regeneration.

[0067] And the battery (110) can be configured to be connected in parallel with the input terminals (120a, 120b) of the DC / DC converter and the input terminals (131a, 131b) of the first inverter.

[0068]

[0069] Figure 3 illustrates a battery module according to one embodiment of the present invention.

[0070] Referring to FIG. 3, a battery module (20) according to one embodiment of the present invention may include a battery (210), a DC / DC converter (220), an inverter unit (230), and a common capacitor (240). The common capacitor (240) may be connected in parallel to the battery (210). The battery module (20) illustrated in FIG. 3 may include all the components of the battery module (10) illustrated in FIG. 2, and may further include a common capacitor (240).

[0071] According to a battery module (20) according to one embodiment of the present invention, since a single common capacitor can be shared instead of applying individual capacitors to each inverter and converter element, the volume can be reduced, and since a low-voltage capacitor can be applied, the production cost can be reduced.

[0072]

[0073] Figure 4 illustrates a battery module according to one embodiment of the present invention.

[0074] Referring to FIG. 4, the battery module (30) may include a battery (310), a first DC / DC converter (320), an inverter unit (330), and a second DC / DC converter (340). The first DC / DC converter (320) may have the same structure and perform the same role as the DC / DC converter (120, 220) illustrated in FIG. 2 or FIG. 3. In addition, the battery module (30) includes all of the configurations of the battery module (10) illustrated in FIG. 2, and may further include a second DC / DC converter (340).

[0075] At this time, the input terminals (340a, 340b) of the second DC / DC converter (340) can receive the battery voltage, and the output terminals (340c, 340d) of the second DC / DC converter (340) can output the second DC module voltage. In addition, when configuring a single-phase battery system using the battery module (30), the output terminals (340c, 340d) of the second DC / DC converters (340) included in the single-phase battery system are connected in series to form a second DC system output terminal, and the second DC system output terminal can output a high-voltage DC voltage and provide it to a high-voltage load.

[0076] In addition, when configuring a three-phase battery system using a battery module (30), the second DC system output terminal of each phase can be connected in parallel with the second DC system output terminal of another phase. In addition, the second DC system output terminal can provide a high-voltage DC to a high-voltage load required in a vehicle.

[0077]

[0078] FIG. 5 is a drawing for explaining a connection structure between a plurality of battery modules according to one embodiment of the present invention.

[0079] Referring to FIG. 5, the first battery module (10-1) and the second battery module (10-2) may include the same configuration and may be configured with the same structure. In addition, as described with reference to FIG. 2, the first battery module (10-1) and the second battery module (10-2) may each include a battery (110-1, 110-2), a DC / DC converter (120-1, 120-2), and an inverter unit (130-1, 130-2). Alternatively, as described with reference to FIG. 3, the first battery module (10-1) and the second battery module (10-2) may further include a common capacitor.

[0080] Additionally, a plurality of battery modules may be connected to form a battery system, and the connection relationship between the plurality of battery modules included in the battery system may be as in the structure illustrated in FIG. 5.

[0081] More specifically, the output terminals (130-1c, 130-1d) of the inverter unit included in the first battery module (10-1) may be connected in series with the output terminals (130-2c, 130-2d) of the inverter unit included in the second battery module (10-2). At this time, the output terminal of the inverter unit may mean the output terminal of the second inverter included in the inverter unit. In addition, when the inverter unit outputs the AC module voltage, the inverter (130-1) included in the first battery module and the inverter (130-2) included in the second battery module may be connected in series to output the AC module voltage twice as large. For example, when the AC module voltage is set to 100 V, two inverters (120-1, 120-2) connected in series may output an AC voltage of 200 V. At this time, the magnitude of the AC voltage may mean the maximum value, the root mean square value, or the average value of the AC voltage.

[0082] And the output terminals (120-1c, 120-1d) of the DC / DC converter included in the first battery module (10-1) and the output terminals (120-2c, 120-2d) of the DC / DC converter included in the second battery module (10-2) can be connected in parallel. In one embodiment, one end (120-1d) of the output terminal of the DC / DC converter included in the first battery module (10-1) can be grounded, and one end (120-2d) of the output terminal of the DC / DC converter included in the second battery module (10-2) can be grounded. And the other end (120-1c) of the output terminal of the DC / DC converter included in the first battery module (10-1) and the other end (120-2c) of the output terminal of the DC / DC converter included in the second battery module (10-2) can be connected in parallel to output a DC module voltage. And the output terminals of the DC / DC converter, which are connected in parallel with each other, output the DC module voltage and can be connected to a low-voltage load that uses the DC module voltage as a driving voltage to provide voltage.

[0083] To summarize, the first battery module (10-1) and the second battery module (10-2) can be connected in series with the output terminals of the inverter unit, and the output terminals of the DC / DC converter can be connected in parallel.

[0084]

[0085] Figure 6 illustrates a single-phase battery system according to one embodiment of the present invention.

[0086] Referring to FIG. 6, a single-phase battery system (100) according to an embodiment of the present invention may include a plurality of battery modules (10-1, 10-2, …, 10-N). Each of the plurality of battery modules (10-1, 10-2, …, 10-N) included in the single-phase battery system (100) may be identical to the battery modules (10, 20, 30) illustrated in FIGS. 2 to 4. In addition, the plurality of battery modules (10-1, 10-2, …, 10-N) included in the single-phase battery system (100) may have a connection structure between battery modules illustrated in FIG. 5.

[0087] Referring again to FIG. 2, a battery module according to one embodiment of the present invention may include a direct current module output terminal (120c, 120d) corresponding to an output terminal of a DC / DC converter, and an alternating current module output terminal (135c, 135d) corresponding to an output terminal of an inverter unit.

[0088] And referring to FIG. 6, a single-phase battery system (100) according to one embodiment of the present invention may include a DC system output terminal (120c, 120d) configured by connecting DC module output terminals included in each of a plurality of battery modules in parallel. At this time, the DC system output terminal (120c, 120d) may output a DC system voltage, and the DC system voltage may have the same magnitude as the DC module voltage output from the output terminal of the DC / DC converter.

[0089] In addition, a single-phase battery system (100) according to one embodiment of the present invention may include an AC system output terminal (130-1c, 130-Nd) configured by serially connecting output terminals of inverter units included in each of a plurality of battery modules. In addition, the AC system output terminal (130-1c, 130-Nd) may output an AC system voltage, and the AC system voltage may have a size that is an integer (N) times the AC module voltage output from the output terminal of the inverter unit. Meanwhile, the AC system output terminal may provide AC power to an AC load, and may provide power for one phase (e.g., phase A, phase B, or phase C) of a three-phase AC voltage.

[0090] To summarize, the single-phase battery system (100) can provide various output voltages including a direct current system voltage and an alternating current system voltage by connecting each element of a plurality of battery modules in series / parallel.

[0091] The electric vehicle may include AC loads such as a low-voltage load (R1) operating at low voltage, a high-voltage load (R2) operating at high voltage, and a motor (M) operating at high-voltage three-phase AC voltage. In addition, the low-voltage load may use the DC system voltage as its driving voltage, and the AC load may use the AC system voltage as its driving voltage.

[0092]

[0093] FIG. 7 illustrates a three-phase battery system (1000) according to one embodiment of the present invention.

[0094] Referring to FIG. 7, a three-phase battery system (1000) according to one embodiment of the present invention includes a plurality of single-phase battery systems (100-1, 100-2, 100-3), and each single-phase battery system may include a plurality of battery modules.

[0095] A three-phase battery system (1000) according to one embodiment of the present invention may include three single-phase battery systems (100-1, 100-2, 100-3). Furthermore, the single-phase battery systems may include an AC system output terminal configured by serially connecting output terminals of inverter units. Furthermore, each AC system output terminal included in the three single-phase battery systems may output different AC voltages having the same magnitude and phase difference.

[0096] For example, each AC system output terminal included in a three-phase battery system can output a different AC voltage with a phase difference of 120 degrees. Therefore, a three-phase battery system can output a three-phase AC voltage and provide a driving voltage to a motor that uses the three-phase AC voltage as a driving voltage.

[0097] Each of the plurality of single-phase battery systems (100-1, 100-2, 100-3) included in the three-phase battery system (1000) according to one embodiment of the present invention may include a DC system output terminal in which a plurality of DC / DC converters are connected in parallel with each other to output a DC system voltage. In addition, the DC system output terminals included in each of the plurality of single-phase battery systems (100) may be connected in parallel with each other.

[0098] To explain again, when a single-phase battery system (100) includes N DC / DC converters, all 3*N DC / DC converters included in a three-phase battery system (1000) can be connected in parallel to output a DC module voltage or a DC system voltage having the same magnitude as the DC module voltage.

[0099]

[0100] FIG. 8 is a block diagram illustrating a battery module and a single-phase battery system for a vehicle according to one embodiment of the present invention.

[0101] Referring to FIG. 8, a battery module (10) according to one embodiment of the present invention may include a battery (110), a DC / DC converter (120), and an inverter unit (130). The DC / DC converter (120) may convert a battery voltage into a DC module voltage and output it, and the inverter unit (130) may convert a battery voltage into an AC module voltage and output it.

[0102] And the DC system voltage can be configured by connecting multiple DC module voltages in parallel, and the DC system voltage and the DC module voltage can have the same magnitude. And the DC system voltage can be the supply voltage for a low-voltage load.

[0103] In addition, the AC system voltage can be configured by connecting multiple AC module voltages in series, and when N AC module voltages are connected in series, the AC system voltage can be configured as N times the AC module voltage. In addition, the AC system voltage can be a supply voltage to the AC load, and when the AC load is a three-phase load, the AC system voltage can be configured as an A-phase, B-phase, or C-phase voltage. The A-phase, B-phase, or C-phase voltages can have the same magnitude and a phase difference of 120 degrees, respectively.

[0104] FIG. 9 is a block diagram illustrating an inverter unit according to one embodiment of the present invention.

[0105] Referring to FIG. 9, an inverter unit according to one embodiment of the present invention may include a first inverter (131), a transformer (132), a rectifier (133), a capacitor (134), and a second inverter (135).

[0106] The first inverter (131) can convert the battery voltage into a primary AC voltage, and the transformer (132) can convert the primary AC voltage into a secondary AC voltage. In one embodiment, the transformer can have a transformation ratio of 1:3. In addition, the rectifier (133) can convert the secondary AC voltage into a DC voltage, and the capacitor (134) can be connected in parallel to the output terminal of the rectifier (133) so that the DC voltage output from the rectifier (133) and the voltage across the capacitor (134) are the same. In addition, the second inverter (135) can convert the voltage across the capacitor (134), i.e., the DC voltage output from the rectifier (133), into an AC module voltage and output the converted voltage.

[0107] And the first inverter (131) can operate as an inverter when the motor is driven and as a rectifier during regeneration. In addition, the rectifier (133) can operate as a rectifier when the motor is driven and as an inverter during regeneration.

[0108]

[0109] The three-phase battery system (1000) may further include a control unit (not shown). The control unit can individually control each battery module, and can individually control the inverter unit and DC / DC converter included in each battery module. Therefore, according to one embodiment of the present invention, energy efficiency can be increased by performing balancing control for each power conversion device and each battery module.

[0110] In addition, the control unit can control the blocking of only the battery modules in which a problem occurs when a problem occurs in some of the N battery modules, thereby ensuring the reliability of the entire system.

[0111] In addition, since the control unit can individually control each battery module, even if deterioration occurs differently in each battery module, the deterioration performance of each battery module can be actively controlled.

[0112]

[0113] FIG. 10 is a drawing for explaining the structure of an inverter according to one embodiment of the present invention.

[0114] Referring to FIG. 10, the first inverter (131) or rectifier (133) may include a plurality of Si-MOSFET (Metal Oxide Semiconductor Field Effect Transistor, MOSFET) elements (1201, 1202, 1203, 1204) and may be configured as an H-bridge single-phase inverter structure.

[0115] Conventional electric vehicle systems primarily use SiC power semiconductors. These SiC power semiconductors are highly efficient and feature fast switching speeds, but are expensive.

[0116] Additionally, conventional electric vehicle systems sometimes use insulated gate bipolar transistors (IGBTs) at low voltages, which are relatively inexpensive but can have slow switching speeds.

[0117] Meanwhile, Si-MOSFET devices have fast switching speeds and are relatively inexpensive, but their performance deteriorates at high voltages, making them difficult to apply to conventional high-voltage electric vehicle systems.

[0118] Since the battery module according to one embodiment of the present invention operates at a low voltage, Si-MOSFET elements can be applied to the inverter. Accordingly, the inverter included in the battery module according to one embodiment of the present invention utilizes multiple Si-MOSFET elements, thereby reducing production costs and achieving fast switching speeds. Consequently, fuel efficiency can be improved, increasing vehicle driving range. Furthermore, as driving range increases, battery capacity can be reduced, thereby reducing costs.

[0119] In addition, the inverter according to one embodiment of the present invention is configured with an H-bridge single-phase inverter structure, so that stability can be maintained even at large currents.

[0120] In addition, in Fig. 10, an H-bridge circuit is configured using four Si-MOSFETs as an example, but it may also be possible to configure an H-bridge circuit by connecting multiple Si-MOSFETs in parallel to enable switching of large currents.

[0121]

[0122] As described above, the present invention is a technology for replacing a conventional electric vehicle driving system that operates at high voltage by connecting standardized battery modules that operate at low voltage in series / parallel, and can provide various outputs by connecting battery modules in series / parallel as needed.

[0123] While representative embodiments of the present invention have been described in detail above, those skilled in the art will appreciate that various modifications to the above-described embodiments are possible without departing from the scope of the present invention. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be defined not only by the claims set forth below but also by equivalents thereof.

[0124] 1: Conventional electric vehicle drive system 11: High-voltage battery pack

[0125] 12: Power conversion device

[0126] 10: Battery module 110: Battery

[0127] 120: DC / DC converter 130: Inverter unit

[0128] 131: Primary inverter 132: Transformer

[0129] 133: Rectifier 134: Capacitor

[0130] 135: Secondary inverter

[0131] 100: Single-phase battery module system

[0132] 1000: Three-phase battery module system

Claims

1. A battery that outputs battery voltage; A DC / DC converter that converts the battery voltage into a DC module voltage smaller than the battery voltage and outputs the same; and It includes an inverter unit that converts the above battery voltage into an AC module voltage and outputs it, The inverter unit comprises a first inverter that converts the battery voltage into a primary AC voltage, a transformer that converts the primary AC voltage into a secondary AC voltage, a rectifier that converts the secondary AC voltage into a DC voltage, a capacitor connected in parallel to an output terminal of the rectifier, and a second inverter that converts the voltage of the capacitor into the AC module voltage. Battery modules for vehicles.

2. In paragraph 1, Further comprising a capacitor connected in parallel with the battery; Battery modules for vehicles.

3. In paragraph 1, The above battery is configured to be connected in parallel with the input terminal of the DC / DC converter and the input terminal of the first inverter. Battery modules for vehicles.

4. In paragraph 1, The output terminal of the above DC / DC converter is configured to be connected in parallel with a low-voltage load that uses the DC module voltage as a driving voltage. Battery modules for vehicles.

5. In paragraph 1, The above inverter unit is configured to supply AC power to an AC load having a driving voltage that is an integer multiple of the size of the AC module voltage. Battery modules for vehicles.

6. In paragraph 1, The output frequency of the first inverter and the output frequency of the second inverter are configured to be different from each other. Battery modules for vehicles.

7. A plurality of vehicle battery modules including a DC module output terminal for outputting a DC module voltage smaller than the battery voltage from the internal battery voltage, and an AC module output terminal for outputting an AC module voltage; A DC system output terminal configured by connecting the DC module output terminals included in each of the plurality of vehicle battery modules in parallel; and An AC system output terminal including the AC module output terminals included in each of the plurality of vehicle battery modules are connected in series, Single phase battery system for vehicles.

8. In paragraph 7, Each of the above plurality of vehicle battery modules, A battery that outputs battery voltage; A DC / DC converter that converts the battery voltage into a DC module voltage smaller than the battery voltage and outputs the same; and It includes an inverter unit that converts the above battery voltage into an AC module voltage and outputs it, The inverter unit comprises a first inverter that converts the battery voltage into a primary AC voltage, a transformer that converts the primary AC voltage into a secondary AC voltage, a rectifier that converts the secondary AC voltage into a DC voltage, a capacitor connected in parallel to an output terminal of the rectifier, and a second inverter that converts the voltage of the capacitor into the AC module voltage. Single phase battery system for vehicles.

9. In paragraph 8, The above battery is configured to be connected in parallel with the input terminal of the DC / DC converter and the input terminal of the first inverter. Single phase battery system for vehicles.

10. In paragraph 7, The above DC system output terminal is configured to be connected in parallel with a low voltage load that uses the DC module voltage as a driving voltage. Single phase battery system for vehicles.

11. In paragraph 7, The above AC system output terminal is configured to be connected to an AC load having a driving voltage that is an integer multiple of the AC module voltage. Single phase battery system for vehicles.

12. In paragraph 8, The transformation ratio of the above transformer is determined based on the ratio of the battery voltage and the voltage of the AC system output terminal. Single-phase battery system for vehicles 13. In paragraph 8, Each of the plurality of vehicle battery modules further includes a second DC / DC converter that converts the battery voltage into a second DC module voltage greater than the DC module voltage and outputs the converted voltage, The above vehicle single-phase battery system further includes a second DC system output terminal configured such that the output terminals of the second DC / DC converters included in each of the plurality of vehicle battery modules are connected in series. Single phase battery system for vehicles.

14. A plurality of vehicle single-phase battery systems are configured based on a plurality of vehicle battery modules including a DC module output terminal that outputs a DC module voltage lower than the battery voltage from the internal battery voltage, and an AC module output terminal that outputs an AC module voltage, and a DC system output terminal configured by connecting the DC module output terminals included in each of the plurality of vehicle battery modules in parallel, and an AC system output terminal configured by connecting the AC module output terminals included in each of the plurality of vehicle battery modules in series, The AC system output terminals included in each of the above multiple vehicle single-phase battery systems output different AC system voltages having the same magnitude and the same phase difference. Three-phase battery system for vehicles.

15. In paragraph 14, Each of the above multiple vehicle battery modules A battery that outputs battery voltage; A DC / DC converter that converts the battery voltage into a DC module voltage smaller than the battery voltage and outputs the same; and It includes an inverter unit that converts the above battery voltage into an AC module voltage and outputs it, The inverter unit comprises a first inverter that converts the battery voltage into a primary AC voltage, a transformer that converts the primary AC voltage into a secondary AC voltage, a rectifier that converts the secondary AC voltage into a DC voltage, a capacitor connected in parallel to an output terminal of the rectifier, and a second inverter that converts the voltage of the capacitor into the AC module voltage. Three-phase battery system for vehicles.

16. In paragraph 15, The above battery is configured to be connected in parallel with the input terminal of the DC / DC converter and the input terminal of the first inverter. Three-phase battery system for vehicles.

17. In paragraph 15, The transformation ratio of the above transformer is determined based on the ratio of the battery voltage and the voltage of the AC system output terminal. Three-phase battery system for vehicles.

18. In paragraph 14, The DC system output terminals included in each of the above multiple vehicle single-phase battery systems are connected in parallel with each other and configured to be connected in parallel with a low-voltage load that uses the DC module voltage as a driving voltage. Three-phase battery system for vehicles.

19. In paragraph 14, The AC system output terminal included in each of the above multiple vehicle single-phase battery systems is configured to supply power to an AC load using the voltage of the AC system output terminal as a driving voltage. Three-phase battery system for vehicles.

20. In paragraph 14, Each of the above multiple vehicle single-phase battery systems comprises multiple vehicle battery modules, The number of the plurality of vehicle battery modules included in each of the plurality of vehicle single-phase battery systems is configured to be identical to each other. Three-phase battery system for vehicles.

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