Vehicle, battery charging method for vehicle, and recording medium

Abstract

This disclosure relates to a vehicle, a battery charging method for the vehicle, and a recording medium. The vehicle includes: a boost converter configured to bypass or convert a stack voltage in response to a first control signal and output the bypassed or converted stack voltage as a first voltage; a first switching unit configured to be switched in response to a first switching signal to form a main path to supply the first voltage to the battery; a buck converter configured to convert the level of the first voltage in response to a second control signal and output the converted first voltage as a second voltage to the battery; a second switching unit configured to be switched in response to a second switching signal to form a bypass path to supply the second voltage to the battery; and a controller configured to check the level of the voltage charged in the battery and generate a first control signal and a second control signal, as well as a first switching signal and a second switching signal based thereon.

Description

Technical Field

[0001] Embodiments of this disclosure relate to a vehicle including a fuel cell, a battery charging method for the vehicle, and a recording medium in which a program for performing the method is recorded. Background Technology

[0002] In vehicles equipped with fuel cells that include a battery stack, the battery is charged using the electricity generated in the fuel cell, and loads such as electric motors are driven by the electricity charged in the battery.

[0003] For this purpose, the vehicle includes a DC / DC converter to boost the stack voltage generated in the fuel cell. However, in this case, overcurrent may occur when the voltage level charged in the battery is lower than the stack voltage level, which could damage the components of the DC / DC converter or the battery.

[0004] The information disclosed in the background section above is helpful in understanding the background of this disclosure and should not be construed as an admission that such information constitutes any part of the prior art. Summary of the Invention

[0005] Therefore, embodiments of this disclosure relate to a vehicle including a fuel cell, a battery charging method for the vehicle, and a recording medium containing a program for performing the method, which substantially eliminates one or more problems caused by the limitations and disadvantages of related technologies.

[0006] The purpose of this disclosure is to provide a vehicle including a fuel cell that can prevent overcurrent damage to components or the battery when the voltage level charged in the battery is lower than the stack voltage level, a battery charging method for the vehicle, and a recording medium in which a program for performing the method is recorded.

[0007] A vehicle including a fuel cell according to an exemplary embodiment may include: a battery; a battery stack including a plurality of cell units stacked on top of each other; a boost converter configured to bypass or convert the stack voltage output from the battery stack in response to a first control signal and output the bypassed or converted stack voltage as a first voltage; a first switching unit configured to be switched in response to a first switching signal to form a main path to supply the first voltage to the battery; a buck converter configured to convert the level of the first voltage in response to a second control signal and output the converted first voltage as a second voltage to the battery and having a second rated power lower than the first rated power of the boost converter; a second switching unit configured to be switched in response to a second switching signal to form a bypass path to supply the second voltage to the battery; and a controller configured to check the level of the voltage charged in the battery and generate a first control signal, a second control signal, a first switching signal, and a second switching signal in response to the check result.

[0008] For example, the second rated power can be 5% to 10% of the first rated power.

[0009] For example, the second switching unit may have a third rated power, and the third rated power may be 5% to 10% of the first rated power.

[0010] For example, the second switching unit can be disposed between the boost converter and the buck converter. Alternatively, the second switching unit can be disposed between the buck converter and the battery.

[0011] For example, the controller can generate a first switch signal and a second switch signal, so that the first switch unit and the second switch unit are switched alternately.

[0012] For example, a boost converter may include: a first capacitor disposed between an output terminal on the positive side of the battery stack and an output terminal on the negative side of the battery stack; a first inductor including a first end connected to the output terminal on the positive side of the battery stack; a first diode including a positive terminal connected to a second end of the first inductor; a second capacitor disposed between the negative terminal of the first diode and the output terminal on the negative side of the battery stack; and a first semiconductor switch configured to switch on or off in response to a first control signal. The first semiconductor switch may be connected to the positive terminal of the first diode and the output terminal on the negative side of the battery stack and disposed between the positive and negative output terminals of the first diode, and the controller may generate a first control signal that causes the first semiconductor switch to switch off to form a bypass path, or causes the first semiconductor switch to switch on to form a main path.

[0013] For example, the first switching unit may include a first switch and a second switch. The first switch is disposed between the negative terminal of the first diode and the input terminal on the positive side of the battery. The first switch is switched in response to a first switching signal. The second switch is disposed between the output terminal on the negative side of the battery stack and the input terminal on the negative side of the battery. The second switch is switched in response to a first switching signal.

[0014] For example, a buck converter may include: a second inductor including one side connected to an input terminal on the positive side of the battery; a second semiconductor switch configured to switch on or off in response to a second control signal, the second semiconductor switch being disposed between the negative terminal of a first diode and a second side of the second inductor; and a second diode including a negative terminal connected to the second side of the second inductor and a positive terminal connected to an output terminal on the negative side of the battery stack, and a controller may generate a second control signal that causes the second semiconductor switch to switch on to form a bypass path, or causes the second semiconductor switch to switch off to form a main path.

[0015] For example, the second switching unit may include a third switch and a fourth switch. The third switch is disposed between one side of the second inductor and the input terminal on the positive side of the battery, and is switched in response to a second switching signal. The fourth switch is disposed between the positive terminal of the second diode and the input terminal on the negative side of the battery, and is switched in response to a second switching signal. Optionally, for example, the second switching unit may include a fifth switch and a sixth switch. The fifth switch is disposed between the negative terminal of the first diode and the second semiconductor switch, and is switched in response to a second switching signal. The sixth switch is disposed between the output terminal on the negative side of the battery stack and the positive terminal of the second diode, and is switched in response to a second switching signal.

[0016] For example, each of the second and third rated power ratings can be determined based on the time required for the voltage level charged in the battery to reach the stack voltage level.

[0017] For example, the switch included in the first switching unit or the second switching unit may include a relay, a semiconductor switch, or a diode.

[0018] For example, the vehicle may further include a load stage connected to the main path and configured to receive a first voltage or a voltage charged in the battery.

[0019] For example, the load stage may include an inverter and a motor, the inverter being connected to an input terminal on the positive side of the battery and an input terminal on the negative side of the battery, the inverter being configured to convert a first voltage supplied to the inverter in DC form to an AC first voltage or to convert a voltage charged in the battery in DC form to an AC second voltage, and the motor being configured to be driven in response to the AC first voltage or the AC second voltage.

[0020] According to another exemplary embodiment, a battery charging method for a vehicle includes: a battery; a battery stack including a plurality of cell batteries stacked on top of each other; a boost converter configured to bypass a stack voltage output from the battery stack or to convert the level of the stack voltage and output the bypassed or converted stack voltage as a first voltage; and a buck converter configured to convert the level of the first voltage and output the converted first voltage as a second voltage and having a rated power lower than the rated power of the boost converter. The method may include: checking the level of a voltage charged in the battery; when the checked level of a voltage charged in the battery has not yet reached the level of the stack voltage, forming a bypass path to supply the second voltage formed by converting the level of the stack voltage bypassed from the boost converter to the battery; and when the level of a voltage charged in the battery reaches the level of the stack voltage, forming a main path to supply the first voltage having the level converted by the boost converter to the battery.

[0021] According to another exemplary embodiment, a non-transitory computer-readable recording medium may have a program recorded therein for performing a battery charging method for a vehicle, the vehicle including: a battery stack comprising a plurality of cell batteries stacked on top of each other; a boost converter configured to bypass or convert the stack voltage output from the battery stack and output the bypassed or converted stack voltage as a first voltage; a battery configured to be charged using the first voltage output from the boost converter; and a buck converter configured to convert the level of the first voltage and output the converted first voltage as a second voltage and having a rated power lower than the rated power of the boost converter. When executed by a processor, the program causes the processor to check the level of the voltage charged in the battery; when the checked level of the voltage charged in the battery has not yet reached the level of the stack voltage, a bypass path is formed to supply the second voltage formed by converting the level of the stack voltage bypassed from the boost converter to the battery; and when the level of the voltage charged in the battery reaches the level of the stack voltage, a main path is formed to supply the first voltage having the level converted by the boost converter to the battery, and the recording medium can be read by a computer. Attached Figure Description

[0022] The accompanying drawings, which are included to provide a further understanding of this disclosure and are incorporated in and constitute a part of this application, illustrate embodiments of the disclosure and, together with the description, serve to explain the principles of the disclosure. In the drawings:

[0023] Figure 1 This is a block diagram of a vehicle including a fuel cell according to an exemplary embodiment;

[0024] Figure 2 This is an exemplary graph showing the time it takes for the voltage level charged in the battery to reach the stack voltage level.

[0025] Figure 3 This is a block diagram of a vehicle including a fuel cell according to another exemplary embodiment;

[0026] Figure 4 It is based on Figure 1 A circuit diagram of an exemplary embodiment of the vehicle shown;

[0027] Figure 5 It is based on Figure 3 A circuit diagram of an exemplary embodiment of the vehicle shown;

[0028] Figure 6 This is a flowchart illustrating a battery charging method according to an exemplary embodiment; and

[0029] Figure 7 It is a block diagram of the vehicle based on the second comparative example. Detailed Implementation

[0030] The present disclosure will now be described more fully below with reference to the accompanying drawings, which illustrate various embodiments. However, examples may be embodied in many different forms and should not be considered as limiting to the embodiments set forth herein. These embodiments are, in contrast, arranged so that the present disclosure will be more comprehensive and complete and will more fully convey the scope of the disclosure to those skilled in the art.

[0031] It should be understood that when an element is referred to as being "on" or "below" another element, it may be directly on / below that element, or there may be one or more intermediate elements present.

[0032] When an element is referred to as "on" or "below", the term "below the element" or "on the element" can be used depending on the element.

[0033] In addition, relational terms such as “first,” “second,” “upper / upper / above,” and “lower / lower / below” are used only to distinguish one subject or element from another subject or element, without requiring or relating to any physical or logical relationship or order between the subjects or elements.

[0034] In the following description, vehicles 100A and 100B including fuel cells according to exemplary embodiments will be described with reference to the accompanying drawings.

[0035] Figure 1 This is a block diagram of a vehicle 100A including a fuel cell according to an exemplary embodiment.

[0036] refer to Figure 1 According to an exemplary embodiment, the vehicle 100A may include a battery stack 110, a boost converter 120, a first switching unit 130, a buck converter 140, a second switching unit 150, a battery 160, and a controller 170.

[0037] First, examples of fuel cells that may be included in vehicle 100A will be briefly described below, but this disclosure is not limited to any specific form of fuel cell included in vehicle 100A.

[0038] The fuel cell can be, for example, a polymer electrolyte membrane fuel cell (or proton exchange membrane fuel cell) (PEMFC), which has been most extensively studied as a power source for driving vehicles. The fuel cell can include a stack 110.

[0039] The battery stack 110 may include multiple cell units stacked on top of each other along a first direction. Each cell unit can generate 0.6 volts to 1.0 volts, with an average of 0.7 volts. The number of cell units can be determined based on the amount of electricity to be generated in the fuel cell.

[0040] refer to Figure 1 The boost converter 120, in response to the first control signal C1, bypasses the voltage generated in and output from the battery stack 110 (hereinafter referred to as the "stack voltage") or converts the stack voltage level and outputs that level. The stack voltage is related to the output terminal on the positive side of the battery stack 110 (…). Figure 4 or Figure 5 The output terminal (PO) shown is located on the negative side of the battery stack 110. Figure 4 or Figure 5 The potential difference between NO and NO is shown. In the following text, for ease of description, the voltage output from the boost converter 120 will be referred to as the "first voltage".

[0041] The first control signal C1 can be generated by the controller 170. When the voltage level charged in the battery 160 has not yet reached the stack voltage level, the controller 170 generates the first control signal C1, causing the boost converter 120 to bypass the stack voltage.

[0042] Optionally, when the voltage level charged in battery 160 reaches the stack voltage level, controller 170 performs control, causing boost converter 120 to convert the DC stack voltage level and output a DC voltage having the converted level. For example, boost converter 120 may be a DC / DC converter that boosts the stack voltage and outputs the boosted voltage as a first voltage. In this case, boost converter 120 can increase the stack voltage level to the level required by battery 160 or, as will be discussed later... Figure 4 and Figure 5 The level required for the described load level 180.

[0043] To perform the above operation, the controller 170 can check the voltage level charged in the battery 160 and generate a first control signal C1 based on the check result.

[0044] The first switching unit 130 can be switched on in response to the first switching signal S1, and can form a main path MCP to supply the first voltage output from the boost converter 120 to the battery 160. The first switching signal S1 can be generated by the controller 170. When the voltage level charged in the battery 160 has not yet reached the stack voltage level, the controller 170 can generate the first switching signal S1 to switch the first switching unit 130 off, so that the main path MCP is not formed. Optionally, when the voltage level charged in the battery 160 reaches the stack voltage level, the controller 170 can generate the first switching signal S1 to switch the first switching unit 130 on, so that the main path MCP is formed. That is, when the first switching unit 130 is switched on, the main path MCP can be formed, and the current through the main path MCP can flow from the boost converter 120 to the battery 160.

[0045] In order to perform the above operation, the controller 170 can check the voltage level of the battery 160 and generate a first switching signal S1 based on the check result.

[0046] The buck converter 140 responds to the second control signal C2 by changing the level of the first voltage output from the boost converter 120 and outputting it to the battery 160. In the following text, for ease of description, the voltage output from the buck converter 140 will be referred to as the "second voltage".

[0047] The second control signal C2 can be generated by the controller 170. When the voltage level charged in the battery 160 has not yet reached the stack voltage level, the controller 170 can generate the second control signal C2, causing the buck converter 140 to switch the stack voltage level bypassed from the boost converter 120. Optionally, when the voltage level charged in the battery 160 reaches the stack voltage level, the controller 170 stops the operation of the buck converter 140 via the second control signal C2.

[0048] The boost converter 120 can increase the level of the stack voltage, while the buck converter 140 can decrease the level of the first voltage.

[0049] In order to perform the above operation, the controller 170 can check the level of the voltage charged in the battery 160 and generate a second control signal C2 based on the check result.

[0050] The second switching unit 150 can be switched in response to the second switching signal S2 and can form a bypass path BCP to supply the second voltage output from the buck converter 140 to the battery 160. The second switching signal S2 can be generated by the controller 170. When the voltage level charged in the battery 160 has not yet reached the stack voltage level, the controller 170 can generate the second switching signal S2 to switch the second switching unit 150 on, thereby forming the bypass path BCP. Optionally, when the voltage level charged in the battery 160 reaches the stack voltage level, the controller 170 can generate the second switching signal S2 to switch the second switching unit 150 off, thereby not forming the bypass path BCP. That is, when the second switching unit 150 is switched on, a bypass path BCP can be formed, through which current can flow from the boost converter 120 to the battery 160.

[0051] In order to perform the above operation, the controller 170 can check the level of the voltage charged in the battery 160 and generate a second switching signal S2 based on the check result.

[0052] As described above, when the first switch unit 130 is switched on, the second switch unit 150 is switched off, and when the first switch unit 130 is switched off, the second switch unit 150 is switched on. Therefore, the controller 170 can generate a first switch signal S1 and a second switch signal S2, so that the first switch unit 130 and the second switch unit 150 are switched alternately.

[0053] According to the embodiment, the rated power of the buck converter 140 (hereinafter referred to as the "second rated power") is lower than the rated power of the boost converter 120 (hereinafter referred to as the "first rated power").

[0054] If the voltage level charged in battery 160 has not yet reached the stack voltage level, the internal components of boost converter 120 or battery 160 may be damaged when current generated by boost converter 120 with high rated power flows through the main path MCP. (See later...) Figure 4 This will be described in detail.

[0055] However, according to the embodiment, when the voltage level charged in the battery 160 has not yet reached the stack voltage level, the current flows to the battery 160 through the bypass path BCP formed by the buck converter 140 with low rated power and the second switching unit 150, instead of flowing through the main path MCP, thereby preventing damage to the boost converter 120 and the battery 160.

[0056] According to the embodiments, the second rated power may be 5% to 10% of the first rated power, but this disclosure is not limited thereto.

[0057] Additionally, the rated power (hereinafter referred to as "third rated power") of the second switching unit 150, which forms the bypass path BCP together with the buck converter 140, may be 5% to 10% of the first rated power.

[0058] In addition, each of the second and third rated power can be determined based on the time (or time period) required for the voltage level charged in the battery 160 to reach the stack voltage level.

[0059] Figure 2 This is an exemplary graph showing the time taken for the voltage VC charged in battery 160 to reach the stack voltage level VS, where the horizontal axis represents time and the vertical axis represents the voltage VC charged in battery 160.

[0060] refer to Figure 2 In the first case 310, the voltage VC charged in battery 160 reaches the stack voltage level VS in a first time T1. In the second case 320, the voltage VC charged in battery 160 reaches the stack voltage level VS in a second time T2.

[0061] The values ​​of the second and third rated power can be increased to allow the voltage VC charged in battery 160 to reach the stack voltage level VS more quickly. For example, in a first case where it takes a first time T1 for the voltage VC charged in battery 160 to reach the stack voltage level VS, each of the second and third rated power can be 10% of the first rated power. In a second case where it takes a second time T2 for the voltage VC charged in battery 160 to reach the stack voltage level VS, each of the second and third rated power can be 5% of the first rated power. However, this disclosure is not limited to any specific ratio of each of the second and third rated power to the first rated power.

[0062] Figure 3 This is a block diagram of a vehicle 100B including a fuel cell according to another exemplary embodiment.

[0063] and Figure 1 The vehicle shown is similar to the 100A. Figure 3 The vehicle 100B shown may include a battery stack 110, a boost converter 120, a first switching unit 130, a buck converter 140, a second switching unit 150, a battery 160, and a controller 170.

[0064] However, despite Figure 1 The vehicle 100A shown is configured such that the second switching unit 150 is located between the buck converter 140 and the battery 160, but Figure 3 The vehicle 100B shown is configured such that the second switching unit 150 is located between the boost converter 120 and the buck converter 140. Besides the location of the second switching unit 150... Figure 3 The vehicle 100B shown is Figure 1 The vehicle shown is the same as vehicle 100A. That is, Figure 3 The battery stack 110, boost converter 120, first switching unit 130, buck converter 140, second switching unit 150, battery 160, and controller 170 shown are respectively connected to... Figure 1 The battery stack 110, boost converter 120, first switching unit 130, buck converter 140, second switching unit 150, battery 160 and controller 170 shown correspond to each other, and therefore their repeated descriptions will be omitted.

[0065] In the following text, reference will be made to Figure 4 describe Figure 1 The example shown is an implementation of a vehicle 100A that includes a fuel cell.

[0066] Figure 4 It is based on Figure 1 The circuit diagram shown is an exemplary embodiment of the vehicle 100A.

[0067] Figure 4 The vehicle 100A shown may include a battery stack 110, a boost converter 120A, a first switching unit 130A, a buck converter 140A, a second switching unit 150A, a battery 160, and a controller 170A. Figure 4 The battery stack 110, boost converter 120A, first switching unit 130A, buck converter 140A, second switching unit 150A, battery 160, and controller 170A shown respectively perform operations related to… Figure 1 The battery stack 110, boost converter 120, first switching unit 130, buck converter 140, second switching unit 150, battery 160 and controller 170 shown have the same function, and therefore their repeated descriptions will be omitted.

[0068] also, Figure 4 The boost converter 120A, the first switching unit 130A, the buck converter 140A, the second switching unit 150A, and the controller 170A shown are... Figure 1 The corresponding embodiments of the boost converter 120, the first switching unit 130, the buck converter 140, the second switching unit 150, and the controller 170 shown correspond to each other.

[0069] The boost converter 120A may include a first capacitor CA1 and a second capacitor CA2, a first inductor L1, a first diode D1, and a first semiconductor switch.

[0070] The first capacitor CA1 can be disposed between the output terminal PO on the positive side of the battery stack 110 and the output terminal NO on the negative side of the battery stack 110.

[0071] The first inductor L1 has one end connected to the output terminal PO on the positive side of the battery stack 110 and the other end connected to the positive terminal of the first diode D1. That is, the first inductor L1 is disposed between the output terminal PO on the positive side of the battery stack 110 and the positive terminal of the first diode D1.

[0072] The first diode D1 has a positive terminal connected to the other end of the first inductor L1.

[0073] The second capacitor CA2 can be placed between the negative terminal of the first diode D1 and the output terminal NO on the negative side of the battery stack 110.

[0074] The first capacitor CA1 and the second capacitor CA2 are smoothing capacitors.

[0075] The first semiconductor switch can be switched to be on or off in response to the first control signal C1, and can be connected to both the positive terminal of the first diode D1 and the output terminal NO of the negative terminal of the battery stack 110 at the same time as being located between the positive terminal of the first diode D1 and the output terminal NO of the negative terminal of the battery stack 110.

[0076] The first semiconductor switch can be implemented as an insulated-gate bipolar transistor (IGBT) or a field-effect transistor (FET). For example, as Figure 4 As shown, the first semiconductor switch can be implemented as a first transistor SS1. The first transistor SS1 may include a gate G connected to the first control signal C1, a drain D connected to the positive terminal of the first diode D1, and a source S connected to the output terminal NO on the negative side of the battery stack 110.

[0077] The operation of the boost converter 120A with the above configuration will be described below.

[0078] When the voltage level charged in battery 160 is lower than the stack voltage level and it is therefore desired to form a bypass path BCP, the first transistor SS1, acting as a first semiconductor switch, can be turned off in response to the first control signal C1 output from controller 170A, and current can flow in the direction indicated by arrow CP. On the other hand, when the voltage level charged in battery 160 reaches the stack voltage level and it is therefore desired to form a main path MCP, the first transistor SS1, acting as a first semiconductor switch, can be turned on in response to the first control signal C1 output from controller 170A, and can perform an operation to boost the stack voltage.

[0079] The first switching unit 130A may include a first switch 132 and a second switch 134.

[0080] The first switch 132 can be located between the negative terminal of the first diode D1 and the input terminal PI on the positive side of the battery 160, and can be switched to be on or off in response to the first-1 switch signal S11.

[0081] The second switch 134 can be located between the output terminal NO on the negative side of the battery stack 110 and the input terminal NI on the negative side of the battery 160, and can be switched to be on or off in response to the first-second switch signal S12.

[0082] The first switch 132 and the second switch 134 can be switched on or off simultaneously. Therefore, the first-1 switch signal S11 and the first-2 switch signal S12 can be the same signal. Here, each of the first-1 switch signal S11 and the first-2 switch signal S12 corresponds to the first switch signal S1 mentioned above.

[0083] The buck converter 140A may include a second inductor L2, a second semiconductor switch, and a second diode D2.

[0084] The second inductor L2 may include one end connected to the input terminal PI on the positive side of the battery 160 via the second switching unit 150A and the other end connected to the negative terminal of the second diode D2. That is, the second inductor L2 may be disposed between the input terminal PI on the positive side of the battery 160 and the negative terminal of the second diode D2. Alternatively, the second inductor L2 may be connected to both the input terminal PI on the positive side of the battery 160 and the negative terminal of the second diode D2.

[0085] The second semiconductor switch can be switched on or off in response to the second control signal C2, and can be connected to both the cathode of the first diode D1 and the other end of the second inductor L2 simultaneously, while being positioned between the cathode of the first diode D1 and the other end of the second inductor L2. Similar to the first semiconductor switch, the second semiconductor switch can also be implemented as an IGBT or a FET. For example, as... Figure 4 As shown, the second semiconductor switch can be implemented as a second transistor SS2. The second transistor SS2 may include a gate G connected to the second control signal C2, a drain D connected to the negative terminal of the first diode D1, and a source S connected to the other end of the second inductor L2 (i.e., the negative terminal of the second diode D2).

[0086] The second diode D2 may include the negative terminal connected to the other end of the second inductor L2 and the positive terminal connected to the output terminal NO on the negative side of the battery stack 110.

[0087] The operation of the buck converter 140A with the above configuration will be described below.

[0088] When the voltage level charged in battery 160 is lower than the stack voltage level and therefore a bypass path BCP is desired, the second transistor SS2, which is a second semiconductor switch, can be turned on in response to the second control signal C2 output from controller 170A.

[0089] On the other hand, when the voltage level charged in the battery 160 reaches the stack voltage level and thus it is desired to form the main path MCP, the second transistor SS2, which is the second semiconductor switch, can be turned off in response to the second control signal C2 output from the controller 170A.

[0090] As mentioned above, when a main path MCP is formed, a bypass path BCP may not be formed, and when a main path MCP is not formed, a bypass path BCP may be formed.

[0091] The fact that the first rated power of boost converters 120 and 120A is higher than the second rated power of buck converters 140 and 140A means that the first inductor L1 and the first diode D1 included in boost converter 120A can withstand higher currents than the second inductor L2 and the second diode D2 included in buck converter 140A without being damaged. For example, the second inductor L2 and the second diode D2 may only be able to withstand about 5% to 10% of the current level that the first inductor L1 and the first diode D1 can withstand.

[0092] The second switching unit 150A may include a third switch 152 and a fourth switch 154.

[0093] The third switch 152 can be located between one end of the second inductor L2 and the input terminal PI on the positive side of the battery 160, and can be switched to be on or off in response to the second-1 switch signal S21.

[0094] The fourth switch 154 can be located between the positive terminal of the second diode D2 and the input terminal NI on the negative side of the battery 160, and can be switched to be on or off in response to the second-second switch signal S22.

[0095] The third switch 152 and the fourth switch 154 can be switched on or off simultaneously. Therefore, the second-first switch signal S21 and the second-second switch signal S22 can be the same signal. Each of the second-first switch signal S21 and the second-second switch signal S22 corresponds to the second switch signal S2 mentioned above.

[0096] The fact that the first rated power of boost converters 120 and 120A is higher than the third rated power of the second switching unit 150A means that the first inductor L1 and the first diode D1 included in boost converter 120A can withstand higher currents than the third switch 152 and the fourth switch 154 included in the second switching unit 150A without being damaged. For example, the third switch 152 and the fourth switch 154 may only be able to withstand about 5% to 10% of the current level that the first inductor L1 and the first diode D1 can withstand.

[0097] In the following text, reference will be made to Figure 5 describe Figure 3 The example shown is an implementation of a vehicle 100B that includes a fuel cell.

[0098] Figure 5 It is based on Figure 3 The circuit diagram shown is an exemplary embodiment of the vehicle 100B.

[0099] Figure 5 The vehicle 100B shown may include a battery stack 110, a boost converter 120A, a first switching unit 130A, a buck converter 140A, a second switching unit 150B, a battery 160, and a controller 170A.

[0100] although Figure 4 The vehicle 100A shown is configured such that the second switching unit 150A is located between the buck converter 140A and the battery 160, but Figure 5 The vehicle 100B shown is configured such that the second switching unit 150B is located between the boost converter 120A and the buck converter 140A. Apart from this difference, Figure 5 The vehicle 100B shown is Figure 4The vehicle shown is the same as 100A, and therefore its repeated description will be omitted. Therefore, only the configurations shown below will be described in relation to... Figure 4 The positions shown are different Figure 5 The second switch unit 150B is shown.

[0101] The second switching unit 150B may include a fifth switch 156 and a sixth switch 158.

[0102] The fifth switch 156 can be disposed between the negative terminal of the first diode D1 and the drain D of the second transistor SS2, which serves as the second semiconductor switch, and can be switched to be on or off in response to the second-1 switch signal S21.

[0103] The sixth switch 158 can be located between the output terminal NO on the negative side of the battery stack 110 and the positive terminal of the second diode D2, and can be switched to be on or off in response to the second-second switch signal S22.

[0104] The fifth switch 156 and the sixth switch 158 can be switched to ON or OFF simultaneously. Therefore, the second-first switch signal S21 and the second-second switch signal S22 can be the same signal. Each of the second-first switch signal S21 and the second-second switch signal S22 corresponds to the second switch signal S2 mentioned above.

[0105] Included Figure 4 and Figure 5 The first switches 132 and 134 in the first switch unit 130A shown herein include Figure 4 The third switch 152 and the fourth switch 154 in the second switch unit 150A shown, or included in Figure 5 At least one of the fifth switch 156 and the sixth switch 158 in the second switching unit 150B shown may include a relay, a semiconductor switch, or a diode. However, this disclosure is not limited to any specific form of each of the first to sixth switches 132, 134, 152, 154, 156, and 158.

[0106] For example, when a first switch signal S1 with a "high" level (e.g., 12 volts) is supplied from controllers 170 and 170A, each of the first switch 132 and the second switch 134 can be switched on, and when a first switch signal S1 with a "low" level (e.g., 0 volts) is supplied from controllers 170 and 170A, each of the first switch 132 and the second switch 134 can be switched off.

[0107] Furthermore, when a second switch signal S2 with a "high" level (e.g., 12 volts) is supplied from controllers 170 and 170A, each of the third to sixth switches 152, 154, 156, and 158 can be switched on, and when a second switch signal S2 with a "low" level (e.g., 0 volts) is supplied from controllers 170 and 170A, each of the third to sixth switches 152, 154, 156, and 158 can be switched off.

[0108] like Figure 4 and Figure 5 As shown, the vehicles 100A and 100B, which include fuel cells according to embodiments, may further include a load stage 180.

[0109] When the first switching unit 130A switches on to form the main path MCP, the load stage 180 can connect to the main path MCP to receive the first voltage output from the boost converter 120A. Alternatively, regardless of whether the first switching unit 130A forms the main path MCP, the load stage 180 can receive the voltage charged in the battery 160.

[0110] For example, load stage 180 may include inverter 182 and motor 184.

[0111] Inverter 182 is connected to input terminal PI on the positive side of battery 160 and input terminal NI on the negative side of battery 160. Inverter 182 converts the DC first voltage supplied to the inverter or the DC voltage charged in battery 160 into AC voltage, and outputs the AC voltage to motor 184 according to the driving state of vehicles 100A and 100B.

[0112] The electric motor 184 can be driven in response to an AC voltage output from the inverter 182. That is, the electric motor 184 can rotate by receiving an AC voltage from the inverter 182 and can propel vehicles 100A and 100B. For example, the electric motor 184 can be a three-phase AC rotating device including a rotor in which permanent magnets are embedded. However, this disclosure is not limited to any specific form of the electric motor 184.

[0113] Additionally, although not shown, load stages 180 of vehicles 100A and 100B may include components necessary for driving the vehicles, such as electric motor-driven power steering (MDPS), radiator fans, headlights, etc. Each of the various loads included in load stage 180 can be driven by receiving a first voltage or the voltage charged in battery 160 as the drive voltage.

[0114] In the following description, a battery charging method according to an exemplary embodiment performed in the above-described vehicles 100A and 100B including a fuel cell will be described with reference to the accompanying drawings.

[0115] Figure 6 This is a flowchart illustrating a battery charging method 200 according to an exemplary embodiment.

[0116] It is possible Figure 1 , Figure 3 , Figure 4 or Figure 5 The vehicles 100A and 100B shown are performing according to Figure 6 The battery charging method 200 shown is an embodiment of the present invention, but this disclosure is not limited thereto. That is, according to another exemplary embodiment, a battery charging method with... Figure 1 , Figure 3 , Figure 4 or Figure 5 The vehicles 100A and 100B shown are different configurations of vehicles including fuel cells, and are implemented according to... Figure 6 The battery charging method 200 of the embodiment shown.

[0117] Optionally, Figure 1 , Figure 3 , Figure 4 or Figure 5 The controllers 170 and 170A of the vehicles 100A and 100B shown can perform according to Figure 6 The battery charging method 200 shown in the embodiment is not limited thereto. That is, according to another exemplary embodiment, Figure 1 , Figure 3 , Figure 4 or Figure 5 The controllers 170 and 170A of the vehicles 100A and 100B shown can perform operations with respect to... Figure 6 The battery charging method 200 shown in the embodiments is a battery charging method with different processes.

[0118] First, check the voltage level of the battery 160 (step 210).

[0119] After step 210, it is determined whether the level of the voltage being checked in the battery 160 has reached the level of the stack voltage (step 220).

[0120] If the checked voltage level in battery 160 has not yet reached the stack voltage level, a bypass path BCP is formed to supply a second voltage, formed by converting the level of the first voltage bypassed from boost converters 120 and 120A, to battery 160 (step 230), and the program returns to step 220. To this end, upon determining that the checked voltage level in battery 160 has not yet reached the stack voltage level, controllers 170 and 170A use a first switching signal S1 to switch first switching units 130 and 130A to off, and use a second switching signal S2 to switch second switching units 150, 150A, and 150B to on.

[0121] On the other hand, if the checked voltage level in battery 160 has reached the stack voltage level, a main path MCP is formed to supply a first voltage to battery 160 (step 240), the level of which is converted by boost converters 120 and 120A. To this end, upon determining that the checked voltage level in battery 160 has reached the stack voltage level, controllers 170 and 170A use a first switching signal S1 to switch first switching units 130 and 130A to the ON position, and use a second switching signal S2 to switch second switching units 150, 150A, and 150B to the OFF position.

[0122] Typically, vehicles include various electronic control units (ECUs). An ECU is a computer with software capable of performing various functions for the vehicle. The battery charging method 200 according to the above embodiment can be executed by the ECU.

[0123] A recording medium on which a program for performing the battery charging method 200, executed in vehicles 100A and 100B including a fuel cell, is stored may contain a program that includes functions for determining whether the voltage level charged in battery 160 has reached the stack voltage level; forming a bypass path to supply a second voltage to battery 160 when the voltage level charged in battery has not yet reached the stack voltage level; and forming a main path to supply a first voltage to battery 160 when the voltage level charged in battery reaches the stack voltage level. The recording medium may be readable by a computer.

[0124] Computer-readable recording media include all types of recording devices that store data that can be read by a computer system. Examples of computer-readable recording media may include ROM, RAM, CD-ROM, magnetic tape, floppy disk, and optical data storage devices. Computer-readable recording media may also be distributed across network-coupled computer systems, allowing computer-readable code to be stored and executed in a distributed manner by, for example, a processor. Furthermore, programmers skilled in the art to which this disclosure pertains can readily design functional programs, code, and code snippets for implementing battery charging methods.

[0125] The controller described in the exemplary embodiments of this disclosure may be a processor (e.g., a computer, microprocessor, CPU, ASIC, circuit, logic circuit, etc.). The controller may be implemented using a non-transitory memory storing, for example, programs, software instruction reproduction algorithms, etc., and a processor configured to execute the programs, software instruction reproduction algorithms, etc., which, when executed, control the operation of various components of the vehicle. Here, the memory and processor may be implemented as separate semiconductor circuits. Alternatively, the memory and processor may be implemented as a single integrated semiconductor circuit. The processor may comprise one or more processors.

[0126] In the following text, vehicles according to comparative examples and vehicles 100A and 100B according to embodiments will be described.

[0127] Assuming the vehicle according to the first comparative example is the same as vehicles 100A and 100B according to the embodiments, but does not include... Figure 1 , Figure 3 , Figure 4 as well as Figure 5 The step-down converter or second switching unit shown.

[0128] In the vehicle according to the first comparative example, the first semiconductor switch SS1 is in the off state in the boost converters 120 and 120A until the voltage level charged in the battery 160 reaches the stack voltage level, and therefore current flows through the first diode D1 in the direction indicated by the arrow CP, as... Figure 4 As shown. In this situation, with boost converters 120 and 120A short-circuited, a very high level of current can flow in the direction indicated by arrow CP. Therefore, in the case of the vehicle according to the first comparative example, the internal components CA1, L1, D1, and CA2 (especially the first diode D1) of boost converters 120 and 120A may be burned out, and the battery 160 may be damaged.

[0129] On the other hand, in vehicles 100A and 100B according to embodiments, until the voltage level charged in battery 160 reaches the stack voltage level, in the state of short-circuiting boost converters 120 and 120A, a very high level current flows in the direction indicated by arrow CP through the bypass path BCP formed by buck converters 140 and 140A and second switching units 150, 150A and 150B. In this case, when current flows through the bypass path BCP formed by buck converters 140 and 140A (having a second rated power lower than the first rated power of boost converters 120 and 120A) and second switching units 150, 150A and 150B (having a third rated power lower than the first rated power of boost converters 120 and 120A), it is possible to prevent the internal components CA1, L1, D1 and CA2 (especially the first diode D1) of boost converters 120 and 120A from burning out, and to prevent damage to battery 160.

[0130] Figure 7 It is a block diagram of vehicle 10 based on the second comparative example.

[0131] according to Figure 7 The vehicle 10 shown in the second comparative example includes a battery stack 12, a boost converter 20, a first switching unit 30, a buck converter 40, a battery 60, and a controller 70. Here, it is assumed that the battery stack 12, boost converter 20, first switching unit 30, buck converter 40, battery 60, and controller 70 perform the same functions and have the same configuration as the battery stack 110, boost converter 120, first switching unit 130, buck converter 140, battery 160, and controller 170 of vehicles 100A and 100B according to exemplary embodiments of this disclosure. Therefore, Figure 7 The first control signal C1, the second control signal C2, and the first switch signal S1 shown below respectively execute the commands and signals. Figure 4 and Figure 5 The first control signal C1, the second control signal C2, and the first switch signal S1 shown have the same function.

[0132] In the case of the vehicle 10 according to the second comparative example having the above configuration, the buck converter 40 is disposed between the first switching unit 30 and the battery 60 to prevent the internal components of the battery 60 and the boost converter 20 from being damaged when the voltage charged in the battery 60 has not yet reached the stack voltage.

[0133] However, in the case of vehicle 10 according to the second comparative example, the buck converter 40 is located in the path for charging the battery 60 with electricity from the battery stack 12. Therefore, when the battery 60 is charged with electricity, electricity inevitably flows through the buck converter 40, which may lead to a decrease in power charging efficiency.

[0134] On the other hand, in the case of vehicles 100A and 100B according to the implementation method, such as Figure 4 and Figure 5 As shown, Figure 7 The buck converter 40 shown is not present in the path that charges the battery 160 with power from the battery stack 110, thus exhibiting improved power charging efficiency compared to the second comparative example.

[0135] Furthermore, in the case of vehicle 10 according to the second comparative example, the process of transferring drive power from battery stack 12 to load stage (not shown) can be the same as the process in vehicles 100A and 100B according to embodiments. However, in the case of vehicle 10 according to the second comparative example, buck converter 40 is provided in the path of transferring drive power from battery 60 to load stage (not shown). Therefore, when the power charged in battery 60 is supplied to load stage, the power inevitably flows through buck converter 40, which may lead to a reduction in the utilization efficiency of charging power.

[0136] On the other hand, in the case of vehicles 100A and 100B according to the implementation method, such as Figure 4 and Figure 5 As shown, the power charged in battery 160 is supplied directly to load stage 180 instead of through buck converter 40, thus exhibiting improved power utilization efficiency compared to the second comparative example.

[0137] As is evident from the above description, in the case of a vehicle including a fuel cell, a battery charging method for the vehicle, and a recording medium in which a program for executing the method according to the embodiment is recorded, when the voltage level charged in the battery has not yet reached the stack voltage level, current flows to the battery through a bypass path formed by a buck converter (having a lower rated power than the boost converter) and a second switching unit, thereby preventing damage to the boost converter and the battery.

[0138] Furthermore, in the case of a vehicle including a fuel cell, a battery charging method for the vehicle, and a recording medium in which a program for performing the method according to the embodiment is recorded, unlike the second comparative example, the buck converter is not located in the path that supplies power from the battery stack to the battery, thereby exhibiting improved power charging efficiency compared to the second comparative example.

[0139] Furthermore, in the case of a vehicle including a fuel cell, a battery charging method for the vehicle, and a recording medium in which a program for executing the method according to the embodiment is recorded, unlike the second comparative example, the power charged in the battery is directly supplied to the load stage instead of through a buck converter, thereby exhibiting improved utilization efficiency of the charging power compared to the second comparative example.

[0140] The various embodiments described above can be combined with each other without departing from the scope of this disclosure, unless they are contrary to each other. Furthermore, for any element in any of the various embodiments not described in detail, reference may be made to the description of an element having the same reference numerals in another embodiment.

[0141] Although this disclosure has been specifically shown and described with reference to exemplary embodiments thereof, these embodiments have been presented for illustrative purposes only and are not intended to limit the disclosure. It will be apparent to those skilled in the art that various changes in form and detail may be made without departing from the essential characteristics of the embodiments set forth herein. For example, the corresponding configurations set forth in the embodiments may be modified and applied. Furthermore, such modifications and differences in application should not be considered to fall within the scope of this disclosure as defined by the appended claims.

Claims

1. A vehicle including a fuel cell, the vehicle comprising: a battery; a stack including a plurality of unit cells stacked with each other; a boost converter configured to bypass or convert a level of a stack voltage output from the stack in response to a first control signal and output the bypassed or converted stack voltage as a first voltage, the boost converter having a first rated power; a first switching unit configured to be switched to form a main path to supply the first voltage to the battery in response to a first switching signal; a step-down converter configured to convert a level of the first voltage and output the converted first voltage as a second voltage to the battery in response to a second control signal, the step-down converter having a second rated power lower than the first rated power of the boost converter; a second switching unit configured to be switched to form a bypass path to supply the second voltage to the battery in response to a second switching signal; and a controller configured to check a level of a voltage charged in the battery and generate the first control signal, the second control signal, the first switching signal, and the second switching signal in response to a result of checking the level of the voltage charged in the battery, wherein the boost converter includes: a first capacitor provided between an output terminal of a positive side of the stack and an output terminal of a negative side of the stack; a first inductor including one end connected to the output terminal of the positive side of the stack; a first diode including a positive electrode connected to the other end of the first inductor; a second capacitor provided between a negative electrode of the first diode and the output terminal of the negative side of the stack; and a first semiconductor switch configured to be switched to be turned on or turned off in response to the first control signal; wherein the first semiconductor switch is connected to the positive electrode of the first diode and the output terminal of the negative side of the stack and is provided between the positive electrode and the output terminal of the negative side; and wherein the controller generates the first control signal so that the first semiconductor switch is switched to be turned off to form the bypass path or so that the first semiconductor switch is switched to be turned on to form the main path. The second rated power is 5% to 10% of the first rated power.

2. The vehicle of claim 1, wherein, The second switching unit has a third rated power; and 3. The vehicle of claim 2, wherein, wherein the third rated power is 5% to 10% of the first rated power. Each of the second rated power and the third rated power is determined according to a time required for a level of the voltage charged in the battery to reach a level of the stack voltage.

4. The vehicle of claim 3, wherein, The second switching unit is provided between the boost converter and the step-down converter.

5. The vehicle of claim 1, wherein, The second switching unit is provided between the boost converter and the battery.

6. The vehicle of claim 1, wherein, The controller generates the first switching signal and the second switching signal so that the first switching unit and the second switching unit are alternately switched.

7. The vehicle of claim 1, wherein, The first switching unit includes:

8. The vehicle of claim 1, wherein, ​ a first switch disposed between the negative electrode of the first diode and an input terminal of the positive electrode side of the battery and configured to be switched in response to the first switch signal; and a second switch disposed between the output terminal of the negative electrode side of the battery stack and an input terminal of the negative electrode side of the battery and configured to be switched in response to the first switch signal.

9. The vehicle of claim 8, wherein, Each of the first switch and the second switch of the first switch unit includes a relay, a semiconductor switch, or a diode.

10. The vehicle of claim 1, wherein, The step-down converter includes: a second inductor including a first side connected to an input terminal of the positive electrode side of the battery; a second semiconductor switch configured to be switched on or off in response to the second control signal, wherein the second semiconductor switch is disposed between the negative electrode of the first diode and a second side of the second inductor; and a second diode including a negative electrode connected to the second side of the second inductor and a positive electrode connected to the output terminal of the negative electrode side of the battery stack; wherein the controller generates the second control signal such that the second semiconductor switch is switched on to form the bypass path or such that the second semiconductor switch is switched off to form the main path.

11. The vehicle of claim 10, wherein, The second switch unit includes: a third switch disposed between the first side of the second inductor and the input terminal of the positive electrode side of the battery and configured to be switched in response to the second switch signal; and a fourth switch disposed between the positive electrode of the second diode and an input terminal of the negative electrode side of the battery and configured to be switched in response to the second switch signal.

12. The vehicle of claim 11, wherein, Each of the third switch and the fourth switch of the second switch unit includes a relay, a semiconductor switch, or a diode.

13. The vehicle of claim 10, wherein, The second switch unit includes: a fifth switch disposed between the negative electrode of the first diode and the second semiconductor switch and configured to be switched in response to the second switch signal; and a sixth switch disposed between the output terminal of the negative electrode side of the battery stack and the positive electrode of the second diode and configured to be switched in response to the second switch signal.

14. The vehicle of claim 13, wherein, Each of the fifth switch and the sixth switch of the second switch unit includes a relay, a semiconductor switch, or a diode.

15. The vehicle of claim 1, further comprising: a load stage connected to the main path and configured to receive the first voltage or to receive the voltage charged in the battery.

16. The vehicle of claim 15, wherein, The load stage includes: an inverter connected to an input terminal of the positive electrode side of the battery and an input terminal of the negative electrode side of the battery, the inverter configured to convert the first voltage supplied to the inverter in a direct current form into an alternating current first voltage or to convert the voltage charged in the battery in a direct current form into an alternating current second voltage; and a motor configured to be driven in response to the alternating current first voltage or the alternating current second voltage.

17. A method of charging a battery for a vehicle, the vehicle comprising: a battery; A battery stack including a plurality of unit cells stacked with each other; a boost converter configured to bypass or convert a level of a stack voltage output from the battery stack and output the bypassed or converted stack voltage as a first voltage; and a step-down converter configured to convert a level of the first voltage and output the converted first voltage as a second voltage, the step-down converter having a lower rated power than a rated power of the boost converter, wherein the method includes: checking a level of a voltage charged in the battery; when the checked level of the voltage charged in the battery has not reached a level of the stack voltage, forming a bypass path to supply the second voltage formed by converting the level of the stack voltage bypassed from the boost converter to the battery; and when the level of the voltage charged in the battery reaches the level of the stack voltage, forming a main path to supply the first voltage having a level converted by the boost converter to the battery, the boost converter includes: a first capacitor disposed between an output terminal of a positive side of the battery stack and an output terminal of a negative side of the battery stack; a first inductor including one end connected to the output terminal of the positive side of the battery stack; a first diode including a positive electrode connected to the other end of the first inductor; a second capacitor disposed between a negative electrode of the first diode and the output terminal of the negative side of the battery stack; and a first semiconductor switch configured to be switched on or off in response to a first control signal; wherein the first semiconductor switch is connected to the positive electrode of the first diode and the output terminal of the negative side of the battery stack and disposed between the positive electrode and the output terminal of the negative side; and 18.A non-transitory computer-readable recording medium having recorded therein a program for executing a battery charging method for a vehicle, the vehicle comprising: wherein a controller generates the first control signal so that the first semiconductor switch is switched off to form the bypass path or so that the first semiconductor switch is switched on to form the main path. A battery stack including a plurality of unit cells stacked with each other; a boost converter configured to bypass or convert a level of a stack voltage output from the battery stack and output the bypassed or converted stack voltage as a first voltage; a battery configured to be charged with the first voltage output from the boost converter; and a step-down converter configured to convert a level of the first voltage and output the converted first voltage as a second voltage, the step-down converter having a lower rated power than a rated power of the boost converter, wherein, when executed by a processor, the program causes the processor to: check a level of a voltage charged in the battery; when the checked level of the voltage charged in the battery has not reached a level of the stack voltage, form a bypass path to supply the second voltage formed by converting the level of the stack voltage bypassed from the boost converter to the battery; and when the level of the voltage charged in the battery reaches the level of the stack voltage, form a main path to supply the first voltage having a level converted by the boost converter to the battery, when a level of the voltage charged in the battery reaches a level of the stack voltage, a main path is formed to supply the first voltage having a level converted by the boost converter to the battery, wherein the boost converter includes: a first capacitor disposed between an output terminal of a positive electrode side of the battery stack and an output terminal of a negative electrode side of the battery stack; a first inductor including one end connected to the output terminal of the positive electrode side of the battery stack; a first diode including a positive electrode connected to the other end of the first inductor; a second capacitor disposed between a negative electrode of the first diode and the output terminal of the negative electrode side of the battery stack; and a first semiconductor switch configured to be switched on or off in response to a first control signal; wherein the first semiconductor switch is connected to the positive electrode of the first diode and the output terminal of the negative electrode side of the battery stack and disposed between the positive electrode and the output terminal of the negative electrode side; and wherein the controller generates the first control signal so that the first semiconductor switch is switched off to form the bypass path, or so that the first semiconductor switch is switched on to form the main path.

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