Drive control apparatus and method for electric vehicle

Abstract

The invention provides a drive control apparatus and method for an electric vehicle. A method for controlling an electric vehicle using a battery pack including battery cells as a power source in a battery management system may include: receiving a first ignition signal; activating an emergency driving mode; and discharging the battery pack by setting a discharge voltage of the battery pack to a first discharge voltage in the emergency driving mode, the first discharge voltage being lower than a normal discharge voltage in the normal driving mode.

Description

Technical Field

[0001] This disclosure relates to a drive control device and method for electric vehicles. Background Technology

[0002] Electric vehicles are driven by electric motors. These motors are powered by battery packs, which act as high-voltage power sources. The battery pack is a device that stores electrical energy to supply power suitable for the electric vehicle.

[0003] Because the performance of a battery pack will continue to degrade if it is fully discharged, the battery pack in an electric vehicle is controlled to prevent complete discharge. However, it is possible for the battery pack voltage to discharge to the discharge termination voltage. In this case, a dedicated battery charger can be used to charge the battery pack, but there is no solution if a dedicated battery charger is not available. Summary of the Invention

[0004] One or more embodiments provide a drive control device and method for an electric vehicle, capable of controlling the drive of the electric vehicle in an emergency mode where driving becomes difficult due to the battery pack discharging to the discharge termination voltage.

[0005] According to one or more embodiments, a method for controlling an electric vehicle, the electric vehicle using a battery pack comprising individual battery cells as a power source in a battery management system, the method comprising: receiving a first ignition signal; activating an emergency driving mode; and discharging the battery pack by setting the discharge voltage of the battery pack in the emergency driving mode to a first discharge voltage, the first discharge voltage being lower than the normal discharge voltage in a normal driving mode.

[0006] The discharge of the battery pack may include: connecting the battery pack to the inverter of the electric vehicle; controlling the discharge of the battery pack based on a first discharge voltage; and increasing the cumulative number of operations of the emergency driving mode.

[0007] The method may further include: determining whether the cumulative number of operations in the emergency driving mode is less than the first number.

[0008] The method may further include: indicating that the battery pack is depleted when the cumulative number of times the emergency driving mode is operated is greater than or equal to the first number.

[0009] Discharging the battery pack may include: controlling the discharge of the battery pack in a first discharge voltage mode in which the discharge voltage includes a first discharge voltage; and controlling the discharge of the battery pack in a second discharge voltage mode in which the discharge voltage includes a second discharge voltage, the second discharge voltage being lower than the first discharge voltage.

[0010] Controlling the battery pack to discharge in the second discharge voltage mode may include: determining that a second ignition signal is received when the battery pack is not being charged.

[0011] Controlling the discharge of the battery pack in the first discharge voltage mode may include: determining whether the cumulative number of operations in the first discharge voltage mode is less than the first number, wherein controlling the discharge of the battery pack in the second discharge voltage mode includes: determining whether the cumulative number of operations in the second discharge voltage mode is less than the second number.

[0012] The second number can be less than the first number.

[0013] The anode of the battery cell may include a mixture of graphite and silicon as the anode active material.

[0014] The method may further include: operating in emergency driving mode when the remaining capacity of the battery pack is low.

[0015] According to one or more other embodiments, an apparatus for controlling the drive of an electric vehicle that uses a battery pack comprising individual battery cells as a power source, the apparatus comprising: a communication circuit configured to receive a first ignition signal; and a control circuit configured to, in response to the first ignition signal, determine that an emergency driving mode is activated, connect the battery pack to an inverter of the electric vehicle in the emergency driving mode, set the discharge voltage of the battery pack to be lower than the normal discharge voltage of the normal driving mode, and discharge the battery pack.

[0016] The control circuit can be configured to determine the cumulative number of operations in the emergency driving mode, and to operate in the emergency driving mode when the cumulative number of operations is less than the first count.

[0017] The emergency driving mode may include a first discharge voltage mode and a second discharge voltage mode. In the first discharge voltage mode, the discharge voltage includes a first discharge voltage lower than the normal discharge voltage. In the second discharge voltage mode, the discharge voltage includes a second discharge voltage lower than the first discharge voltage. The control circuit is configured to default to the first discharge voltage mode instead of the second discharge voltage mode.

[0018] The control circuit can be configured to determine whether to operate in a second discharge voltage mode after the first discharge voltage mode.

[0019] The control circuit can be configured to operate in the second discharge voltage mode when a second ignition signal is received via the communication circuit while the battery pack is not being charged.

[0020] The control circuit can be configured to operate in the first discharge voltage mode when the cumulative number of operations in the first discharge voltage mode is less than the first number, and to operate in the second discharge voltage mode when the cumulative number of operations in the second discharge voltage mode is less than the second number.

[0021] The second number can be less than the first number.

[0022] The anode of the battery cell may include a mixture of graphite and silicon as the anode active material. Attached Figure Description

[0023] Figure 1 This is a block diagram illustrating an example of an electric vehicle according to one or more embodiments.

[0024] Figure 2 It is a graph showing the charging and discharging curves of a half-cell and a full-cell, using an anode made of conventional graphite-only material and a cathode made of NCA (LiNiCoAlO2) material.

[0025] Figure 3 It is a graph showing the charging and discharging curves of a half-cell and a full-cell according to one or more embodiments, wherein an anode made of a mixed material of graphite and silicon and a cathode made of NCA material are used.

[0026] Figure 4 This is a flowchart illustrating a drive control method according to an emergency driving mode according to one or more embodiments.

[0027] Figure 5 This is a flowchart illustrating a drive control method according to an emergency driving mode according to one or more other embodiments.

[0028] Figure 6 This is a block diagram illustrating a drive control device according to one or more embodiments. Detailed Implementation

[0029] Some aspects of this disclosure and its implementation methods can be more readily understood by referring to the detailed description and accompanying drawings of the embodiments. The described embodiments are provided as examples so that this disclosure will be thorough and complete, and will fully convey aspects of this disclosure to those skilled in the art. Therefore, redundant processes, elements, and techniques that are irrelevant or unrelated to the description of the embodiments, or unnecessary for a person of ordinary skill in the art to fully understand aspects of this disclosure, may be omitted. Unless otherwise stated, the same reference numerals, characters, or combinations thereof denote the same elements throughout the drawings and written description, and therefore their repeated description may be omitted.

[0030] The described embodiments may have various variations and may be implemented in different forms, and should not be construed as being limited to the embodiments shown herein. In the description of the embodiments, the use of "can," "may," or "may not" corresponds to one or more embodiments of this disclosure.

[0031] Those skilled in the art will understand that, in view of the entirety of this disclosure, each suitable feature of the various embodiments of this disclosure may be combined or integrated with each other in part or in whole, and may be technically linked and operated in a variety of suitable ways, and unless otherwise stated or implied, each embodiment may be implemented independently or in combination with each other in any suitable manner.

[0032] It should be understood that when a component, layer, region, or assembly (e.g., device, equipment, circuit, wire, electrode, terminal, conductive film, etc.) is referred to as being "formed on," "on," "connected to," or "(operably, functionally, or communicatively) coupled to" another component, layer, region, or assembly, the component, layer, region, or assembly may be directly formed on the other component, layer, region, or assembly. This can be a direct connection or link to another element, layer, region, or component, or a direct coupling to another element, layer, region, or component, or an indirect connection or link to another element, layer, region, or component, such that one or more intermediate elements, intermediate layers, intermediate regions, or intermediate components may exist. Furthermore, this can be collectively referred to as direct or indirect coupling or connection, and integral or non-integral coupling or connection.

[0033] For example, when a layer, region, or component is referred to as "electrically connected" or "electrically coupled" to another layer, region, or component, the layer, region, or component may be directly electrically connected or coupled to the other layer, region, and / or component, or one or more intermediate layers, regions, or components may be present. One or more intermediate components may include switches, transistors, resistors, inductors, capacitors, diodes, etc. Therefore, the connection is not limited to the connections shown in the accompanying drawings or detailed description, and may also include other types of connections. In describing embodiments, unless explicitly described as a direct connection, the expression for connection indicates an electrical connection, and "direct connection / direct coupling" or "directly on" means that one component is directly connected to or directly coupled to another component, or directly on another component, without any intermediate components.

[0034] Additionally, other expressions describing relationships between components can be interpreted similarly, such as “between,” “immediately between,” or “adjacent to” and “directly adjacent to.” It will be understood that when an element or layer is referred to as “between” two elements or layers, it can be the only element or layer between those two elements or layers, or there may be one or more intermediate elements or layers.

[0035] For the purposes of this disclosure, when expressions such as “at least one of…”, “any one of…”, or “one or more of…” follow a list of elements, they modify the entire list of elements, not individual elements in the list. For example, “at least one of X, Y, and Z,” “at least one of X, Y, or Z,” “at least one selected from the group consisting of X, Y, and Z,” and “at least one selected from the group consisting of X, Y, or Z” can be interpreted as only X, only Y, only Z, any combination of two or more of X, Y, and Z, such as XYZ, XY, YZ, and XZ, or any variation thereof. Similarly, expressions “at least one of A and B” and “at least one of A or B” can include A, B, or A and B. As used herein, “or” generally means “and / or,” and the term “and / or” includes any and all combinations of one or more of the associated listed items. For example, the expression “A and / or B” can include A, B, or A and B. Similarly, expressions such as "at least one of...", "multiple", "one of...", and other prepositional phrases, when appearing before or after a list of elements, modify the entire list of elements, not individual elements within it. When written as "C to D", unless otherwise specified, it indicates C and below.

[0036] It should be understood that although the terms “first,” “second,” “third,” etc., may be used herein to describe various elements, components, regions, layers, and / or parts, these elements, components, regions, layers, and / or parts should not be limited by these terms. These terms do not correspond to a particular order, position, or superiority, and are used only to distinguish one element, component, assembly, region, area, layer, segment, or part from another element, component, assembly, region, area, layer, segment, or part. Therefore, without departing from the spirit and scope of this disclosure, the first element, first component, first region, first layer, or first part described below may be referred to as a second element, second component, second region, second layer, or second part. Describing an element as a “first” element does not require or imply the existence of a second element or other elements. The terms “first,” “second,” etc., may also be used herein to distinguish different categories or groups of elements. For the sake of brevity, the terms “first,” “second,” etc., may respectively mean “first category (or first group),” “second category (or second group),” etc.

[0037] The terminology used herein is for the purpose of describing embodiments only and is not intended to limit this disclosure. As used herein, unless the context clearly indicates otherwise, the singular form is intended to include the plural form, and the plural form is intended to include the singular form. It will be further understood that, when used in this specification, the terms “comprising,” “having,” and “including” specify the presence of the stated features, quantities, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, quantities, steps, operations, elements, components, and / or groups thereof.

[0038] When one or more embodiments can be implemented differently, a particular process sequence may be performed differently than the described sequence. For example, two consecutively described processes may be performed substantially simultaneously or in the reverse order of their description.

[0039] As used herein, the terms “substantially,” “about,” “approximately,” and similar terms are used as approximate terms rather than terms of degree and are intended to explain the inherent deviations of measured or calculated values ​​that would be recognized by those skilled in the art. For example, “substantially” may include a range of + / - 5% of the corresponding value. Taking into account the measurements discussed and the errors associated with the measurement of a particular quantity (i.e., the limitations of the measurement system), “about” or “approximately” as used herein includes the stated value and means within an acceptable range of deviation for a particular value as determined by those skilled in the art. For example, “about” may mean within one or more standard deviations, or within ±30%, ±20%, ±10%, ±5% of the stated value. Furthermore, when describing embodiments of this disclosure, the use of “may” refers to “one or more embodiments of this disclosure.” Additionally, the expression “identical” may mean “substantially identical.” In other words, the expression “identical” may include a range permissible by those skilled in the art. Other expressions may also omit the word “substantially.”

[0040] In some embodiments, well-known structures and arrangements may be described in the accompanying drawings with respect to one or more functional blocks (e.g., block diagrams), units, and / or modules to avoid unnecessarily obscuring the various embodiments. Those skilled in the art will understand that such blocks, units, and / or modules are physically implemented by logic circuitry, individual components, microprocessors, hardwired circuitry, memory elements, wiring connections, and other electronic circuitry. This can be formed using semiconductor-based manufacturing techniques or other manufacturing techniques. Blocks, units, and / or modules implemented by microprocessors or other similar hardware may be programmed and controlled using software to perform the various functions discussed herein, optionally driven by firmware and / or software. Furthermore, each block, unit, and / or module may be implemented by dedicated hardware or a combination of dedicated hardware performing some functions and a processor performing functions different from those of the dedicated hardware (e.g., one or more programmed microprocessors and associated circuitry). Additionally, in some embodiments, blocks, units, and / or modules may be physically divided into two or more interactive independent blocks, units, and / or modules without departing from the scope of this disclosure. Furthermore, in some embodiments, without departing from the scope of this disclosure, blocks, units, and / or modules may be physically combined into more complex blocks, units, and / or modules.

[0041] Unless otherwise defined, all terms used herein (including technical and scientific terms) shall have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains. It will be further understood that, unless expressly defined herein, terms such as those defined in common dictionaries shall be interpreted as having the same meaning as they have in the relevant field and / or in the context of this specification, and shall not be interpreted in an idealized or overly formal sense.

[0042] Figure 1 This is a block diagram illustrating an electric vehicle according to one or more embodiments.

[0043] Reference Figure 1 Electric vehicles may include a battery pack 10, an electronic control unit (ECU) 20 which serves as a vehicle controller, an inverter 30, and an electric motor 40.

[0044] The battery pack 10 can store electrical energy to supply power suitable for an electric vehicle. The battery pack 10 can be connected to an external charging device or load via terminals P+ and P-, and the battery pack 10 can be charged by the charging device and discharged by the load.

[0045] In one or more embodiments, ECU 20 may be configured to send an ignition signal to BMS 300 in response to a user switching the ignition button in the electric vehicle to the ignition position. ECU 20 may also be configured to send an engine shutdown signal to BMS 300 in response to a user switching the ignition button to the engine shutdown position.

[0046] Inverter 30 can be connected between terminals P+ and P- of battery pack 10 and can be configured to convert direct current (DC) from battery 100 included in battery pack 10 to alternating current (AC).

[0047] The motor 40 can be driven using AC power from the inverter 30. For example, a three-phase AC motor can be used as the motor 40. Components within the electric vehicle that receive discharge power from the battery 100 (including the inverter 30 and the motor 40) can be referred to as electrical loads.

[0048] The battery pack 10 may include a battery 100, a relay 200, and a battery management system (BMS) 300.

[0049] Battery 100 can provide high voltage and high capacity through multiple battery modules that are electrically connected in series and / or parallel with each other. For convenience, in Figure 1 The image shows a battery module. For example, the battery pack 10 used in electric vehicles typically has a voltage close to about 400V and a capacity of about 60kWh or more.

[0050] A battery module may include multiple battery cells. These battery cells may be connected in series. Each of the multiple battery cells may be, for example, a lithium-ion battery cell. A battery cell may include a cathode, an anode, a separator, and an electrolyte. The electrolyte may be present between the cathode and the separator, and between the anode and the separator. A battery cell can be charged by moving lithium ions from the cathode to the anode and by storing lithium ions in the anode. Electricity is generated when lithium ions move from the anode to the cathode, and when electrons separated from the lithium ions move along a conductor, and the battery cell can discharge.

[0051] The cathode active material, which constitutes the cathode, can be made from nickel, cobalt, aluminum, manganese, etc. For example, an NCA cathode may include nickel (as a major component), cobalt, aluminum, and lithium oxide.

[0052] The anodic active material used to form the anode is primarily graphite, which can stably store many ions. Compared to graphite, silicon has the advantages of higher energy density, shorter charging time, and higher output, although silicon may expand if repeatedly charged and discharged.

[0053] According to one or more embodiments, a small amount (e.g., about 1% to about 10%) of silicon may be added to the graphite material, and the graphite material having this amount of added silicon may be used as the anode active material.

[0054] Relay 200 controls the current path during charging and discharging of battery 100. Relay 200 may be connected between battery 100 and terminal P+. In one or more embodiments, if relay 200 is turned on during operation of inverter 30 and motor 40 or charging device, battery 100 may enter charging mode or discharging mode. If relay 200 is turned off while battery 100 is operating in charging mode or discharging mode, battery 100 may be switched to idle mode.

[0055] Relay 200 can be switched on and off in response to a switching signal from BMS 300. Relay 200 can be a mechanical contactor that is switched on and off by the magnetic force of a coil, or it can be a semiconductor switch, such as a metal-oxide-semiconductor field-effect transistor (MOSFET).

[0056] BMS 300 may include sensing circuitry 310 and control circuitry 320. BMS 300 may also include communication circuitry 330.

[0057] The sensing circuit 310 can be configured to acquire condition / state parameters of the battery cell. The condition / state parameters of the battery cell may include at least one of the battery cell's voltage, current, and / or temperature. The sensing circuit 310 may include a voltage detector 312, a current detector 314, and / or a temperature detector 316.

[0058] The voltage detector 312 can be connected to the positive and negative terminals of each of the plurality of battery cells included in the battery 100, can measure the voltage across the two ends of each of the battery cells, can generate a voltage signal representing the measured voltage of each of the battery cells, and can send the voltage signal to the control circuit 320.

[0059] A current detector 314 can be connected in series with the battery 100 via the current path between the battery 100 and the inverter 30. The current detector 314 measures the charging / discharging current flowing through the battery 100, generates a current signal representing the measured charging / discharging current, and sends the current signal to the control circuit 320. Because multiple battery cells are connected in series, a common charging / discharging current can flow through all battery cells. The current detector 314 can be implemented using one or more combinations of known current sensing elements such as shunt resistors, Hall effect elements, etc.

[0060] Temperature detector 316 can measure the battery temperature, which is the temperature of battery 100, and can generate a temperature signal representing the measured battery temperature, and can send the temperature signal to control circuit 320. Temperature detector 316 can be placed inside the casing of battery 100 to measure a temperature close to the actual temperature of battery 100. For example, temperature detector 316 can be attached to the surface of at least one battery cell included in battery 100, and can detect the surface temperature of the battery cell as the battery temperature.

[0061] Communication circuitry 330 can be configured to support wired or wireless communication between control circuitry 320 and ECU 20. Wired communication may be, for example, Controller Area Network (CAN) communication, and wireless communication may be, for example, Zigbee® or Bluetooth® communication (Zigbee® is a registered trademark of CONNECTIVITY STANDARD SALLIANCE, Davis, California, and Bluetooth® is a registered trademark of Bluetooth SIG, Inc., Kirkland, Washington). Communication circuitry 330 may include an output device that provides information received from control circuitry 320 and / or ECU 20 in a user- (driver-readable) manner. The output device may be, for example, a display or a speaker.

[0062] Control circuitry 320 may be connected to relay 200, sensing circuitry 310, and communication circuitry 330. Control circuitry 320 may collect voltage signals from voltage detector 312, current signals from current detector 314, and temperature signals from temperature detector 316. In one or more embodiments, control circuitry 320 may use an internally configured analog-to-digital converter (ADC) to convert and record each analog signal collected from voltage detector 312, current detector 314, and temperature detector 316 as a digital value.

[0063] The control circuit 320 may be implemented in hardware using at least one of an application-specific integrated circuit (ASIC), a digital signal processor (DSP), a digital signal processing device (DSPD), a programmable logic device (PLD), a field-programmable gate array (FPGA), a microprocessor, an application processor (AP), a central processing unit (CPU), a graphics processing unit (GPU), and / or other electrical units for performing functions.

[0064] Control circuit 320 controls and manages the overall operation of battery pack 10. Control circuit 320 can use information collected from voltage detector 312, current detector 314, and / or temperature detector 316 to monitor the overall state of battery 100 and the individual battery cells included in battery 100, and can perform various control functions to adjust the state of battery 100 and the individual battery cells included in battery 100. In one or more embodiments, control circuit 320 can monitor the voltage and current of battery 100, control the charging and discharging of battery 100, and perform cell balancing operations. In one or more embodiments, control circuit 320 can monitor the temperature of battery 100 and, if appropriate, control the temperature of battery 100 through cooling, ventilation, C-rate changes, etc., and can disconnect the connection between battery 100 and load via relay 200.

[0065] Control circuit 320 can activate relay 200 in response to an ignition signal. Control circuit 320 can deactivate relay 200 in response to an ignition stop signal. The ignition signal can be a signal requesting a switch from idle mode to charging mode or discharging mode. The ignition stop signal can be a signal requesting a switch from charging mode or discharging mode to idle mode.

[0066] In some embodiments, the on and / or off control of the relay 200 may be performed by the ECU 20 instead of the control circuit 320.

[0067] The control circuit 320 can monitor the voltage of each of the multiple battery cells while charging the battery pack 10, and can identify the maximum voltage of the multiple battery cells. The maximum voltage can represent the highest voltage among the multiple battery cells.

[0068] The control circuit 320 can monitor the voltage of each of the multiple battery cells during the discharge of the battery pack 10, and can identify the minimum voltage. The minimum voltage can represent the lowest voltage among the multiple battery cells.

[0069] If the maximum voltage reaches the upper limit voltage (e.g., a predetermined upper limit voltage, such as about 4.25V) during the charging of battery pack 10, the control circuit 320 may stop charging battery pack 10. The control circuit 320 may perform constant current-constant voltage charging in charging mode.

[0070] If the minimum voltage reaches a lower limit voltage (e.g., a predetermined lower limit voltage, such as about 3V) during the discharge of battery pack 10, control circuit 320 may stop the battery pack 10 from discharging. In this case, the lower limit voltage may be the discharge voltage set in the normal operating mode of the electric vehicle, and in some cases may be referred to as the discharge termination voltage. The discharge voltage refers to the minimum limiting voltage at which battery 100 can safely discharge during operation.

[0071] If, during the discharge of battery pack 10, the remaining capacity of battery pack 10 becomes less than the minimum capacity suitable for driving the electric vehicle, control circuit 320 may disconnect relay 200 to reduce or prevent the possibility of further discharge. At this time, if battery pack 10 has already discharged to the set discharge voltage, the minimum capacity may be the capacity of battery pack 10. If relay 200 is disconnected, the electric vehicle being driven may stop.

[0072] In one or more embodiments, the control circuit 320 may control the minimum voltage of a plurality of individual battery cells during the discharge of the battery pack 10, so that the voltage does not drop below the discharge voltage.

[0073] According to one or more embodiments, if an electric vehicle stops due to insufficient remaining capacity of the battery pack 10, and if it is difficult to charge the battery pack 10, the control circuit 320 may reduce the discharge voltage of the individual battery cells (e.g., from the normal discharge voltage) to enable the electric vehicle to operate in an emergency. This can be achieved by using silicon as the anode active material in the battery cells.

[0074] Figure 2 This is a graph showing the charging and discharging curves of a half-cell and a full-cell, in which the anode is made of conventional graphite-only material and the cathode is made of NCA (LiNiCoAlO2) material. Figure 3 It is a graph showing the charging and discharging curves of a half-cell and a full-cell according to one or more embodiments, wherein the anode is made of a mixed material of graphite and silicon and the cathode is made of NCA material.

[0075] Reference Figure 2 and Figure 3 In the charge / discharge curve, the y-axis represents voltage, and the x-axis represents capacity. The higher the y-value, the higher the output of battery pack 10, and the higher the x-value, the longer battery pack 10 can be used.

[0076] exist Figure 2In the diagram, 210_1 is the charging curve of a single half-cell cathode made of NCA material, and 220_1 is the discharging curve of a single half-cell cathode made of NCA material. 230_1 is the charging curve of a single half-cell anode made only of graphite, and 240_1 is the discharging curve of a single half-cell anode made only of graphite. 250_1 is the charging curve of a full-cell cell including a cathode made of NCA material and an anode made only of graphite, and 260_1 is the discharging curve of a full-cell cell including a cathode made of NCA material and an anode made only of graphite.

[0077] exist Figure 3 In the diagram, 210_2 is the charging curve of a cathode half-cell containing NCA material, and 220_2 is the discharging curve of an anode half-cell containing NCA material. 230_2 is the charging curve of an anode half-cell containing a mixture of graphite and silicon material, and 240_2 is the discharging curve of an anode half-cell containing a mixture of graphite and silicon material. 250_2 is the charging curve of a full cell containing a cathode made of NCA material and an anode made of a mixture of graphite and silicon material, and 260_2 is the discharging curve of a full cell containing a cathode made of NCA material and an anode made of a mixture of graphite and silicon material. The full cell containing a cathode made of NCA material and an anode made of a mixture of graphite and silicon material can be, for example, a battery cell.

[0078] Reference Figure 2 and Figure 3 If a battery cell is charged, the voltage at the anode decreases as the lithium concentration in the anode active material increases, while the voltage at the cathode increases as the lithium concentration in the cathode active material decreases, thereby causing the voltage of the battery cell to increase.

[0079] If a single battery cell discharges, the voltage at the anode increases as the lithium concentration in the anode active material decreases, while the voltage at the cathode decreases as the lithium concentration in the cathode active material increases, resulting in a decrease in the voltage of the single battery cell.

[0080] As described above, if the voltage of a single battery cell (e.g., during the discharge of the battery pack 10) reaches the set discharge voltage (e.g., about 3V), the control circuit 320 disconnects the relay 200 to stop the discharge.

[0081] At this time, observe Figure 2 Even if the discharge voltage of the 270_1, which is set to about 3V, is reduced to about 2.5V, there is almost no additional discharge capacity, and the output (power) that can be provided is probably not much.

[0082] In one or more embodiments, reference is made to Figure 3If the discharge voltage of 270_2, set to approximately 3V (e.g., in normal mode), is reduced to approximately 2.5V (e.g., in emergency driving mode), then... Figure 2 Compared to 270_1, the available output (power) is significantly increased.

[0083] Compare Figure 2 and Figure 3 If a mixture of graphite and silicon is used as the anode active material, additional power can be generated by reducing the discharge voltage compared to using graphite alone. The BMS 300 can take advantage of these characteristics to be able to drive electric vehicles by reducing the discharge voltage (e.g., reducing it to a first discharge voltage) in emergency driving modes (e.g., low battery mode or low battery mode).

[0084] Figure 4 This is a flowchart illustrating a drive control method according to an emergency driving mode according to one or more embodiments.

[0085] Reference Figure 4 If it is difficult to charge the battery pack 10 when the electric vehicle is turned off, the user can try to start the vehicle by pressing the ignition button.

[0086] The ECU 20 can send an ignition signal to the BMS 300 in response to the ignition position of the user's ignition button.

[0087] If the control circuit 320 of the BMS 300 receives an ignition signal (S410), the BMS 300 can check the remaining capacity of the battery pack 10. The control circuit 320 of the BMS 300 can determine, based on the remaining capacity of the battery pack 10, that driving (e.g., normal driving) is not feasible or permitted, and can activate an emergency driving mode.

[0088] In emergency driving mode, the control circuit 320 of BMS 300 can check the number of times emergency driving operation is performed, that is, the number of times emergency driving mode is operated (S420).

[0089] If the number of emergency driving operations is less than the number M (for example, the number of times M is set or the first time number M) (S430), the control circuit 320 of BMS 300 can set the discharge voltage according to the emergency driving mode (S430).

[0090] The discharge voltage in emergency driving mode can be lower than the discharge voltage in normal driving mode (e.g., normal discharge voltage). For example, the discharge voltage in normal driving mode can be set to about 3V, and the discharge voltage in emergency driving mode can be set to about 2.5V.

[0091] In one or more embodiments, since operating the battery pack 10 by reducing the discharge voltage may have a negative impact on the lifespan of the battery 100, the number of times the discharge voltage is reduced can be limited, and the number of times M can be determined.

[0092] The control circuit 320 of the BMS 300 can activate the relay 200 and control the discharge of the battery 100 based on the discharge voltage according to the emergency driving mode (S440). Figure 3 As shown, by reducing the discharge voltage from about 3V to about 2.5V, the battery pack 10 can provide additional power, and the electric vehicle can travel a distance corresponding to the additional power (e.g., a longer distance).

[0093] Next, the control circuit 320 of the BMS 300 can record the number of emergency driving operations. The control circuit 320 of the BMS 300 can increment the number of emergency driving operations (e.g., the emergency driving operation count) by 1 (S450).

[0094] In one or more embodiments, if the number of emergency driving operations is greater than or equal to the set number M (S420), the control circuit 320 of the BMS 300 may indicate that the battery is depleted (S460), and may indicate that further driving is difficult or undesirable.

[0095] In this way, electric vehicles can ensure additional driving range in emergency situations and can move to the nearest charging station to charge battery pack 10.

[0096] Figure 5 This is a flowchart illustrating a drive control method according to an emergency driving mode according to one or more other embodiments.

[0097] Reference Figure 5 Operations S502 to S512 can correspond to Figure 4 Operations S410 to S460 are described in the text.

[0098] If the control circuit 320 of the BMS 300 receives an ignition signal (S502), the control circuit 320 can check the remaining capacity of the battery pack 10. The control circuit 320 of the BMS 300 can determine, based on the remaining capacity of the battery pack 10, that driving is infeasible, not recommended, or not permitted, and can activate an emergency driving mode.

[0099] According to one or more embodiments, the emergency driving mode may include a first discharge voltage mode and a second discharge voltage mode. In the emergency driving mode, the control circuit 320 of the BMS 300 may first operate in the first discharge voltage mode. In the first discharge voltage mode, the control circuit 320 of the BMS 300 may check the number of emergency driving operations in the first discharge voltage mode.

[0100] If the number of emergency driving operations in the first discharge voltage mode is less than the number M (e.g., the first time M or the setting number M) (S504), the control circuit 320 of the BMS 300 can set the first discharge voltage according to the first discharge voltage mode (S506). The first discharge voltage according to the first discharge voltage mode can be a voltage lower than the discharge voltage in the normal driving mode (e.g., the normal discharge voltage). For example, the discharge voltage in the normal driving mode can be set to about 3V, and the first discharge voltage according to the first discharge voltage mode can be set to about 2.5V.

[0101] The control circuit 320 of the BMS 300 can connect the relay 200 and control the discharge of the battery 100 based on the first discharge voltage according to the first discharge voltage mode (S508). Figure 3 As shown, by reducing the discharge voltage from about 3V to about 2.5V, the battery pack 10 can provide additional power, and the electric vehicle can travel a distance corresponding to the additional power.

[0102] Next, the control circuit 320 of the BMS 300 can record the number of emergency driving operations in the first discharge voltage mode (e.g., total number or cumulative number). The control circuit 320 of the BMS 300 can increment the number of emergency driving operations in the first discharge voltage mode by 1 (S510).

[0103] In one or more embodiments, if the number of emergency driving operations in the first discharge voltage mode is greater than or equal to the number of times M is set (S504), the control circuit 320 of the BMS 300 may indicate that the battery is depleted (e.g., indicate that the battery is low) (S512), and may indicate further driving difficulties or limitations.

[0104] Even if additional power is provided to the electric vehicle by discharging the battery 100 at the first discharge voltage according to the first discharge voltage mode, there may still be situations where it is difficult to charge the battery pack 10. For example, if the available driving distance by discharging the battery 100 according to the first discharge voltage is shorter than the distance from the initial location where the vehicle was turned off to the nearest charging station, the electric vehicle may be turned off again before reaching the nearest charging station. In this case, in one or more embodiments, the user can try to start the vehicle again by pressing the ignition button.

[0105] If the BMS 300 receives an ignition signal again (S514) while the battery pack 10 is not being charged, the control circuit 320 of the BMS 300 can operate in the second discharge voltage mode.

[0106] In the second discharge voltage mode, the control circuit 320 of the BMS 300 can check the number of emergency driving operations in the second discharge voltage mode (S516).

[0107] If the number of emergency driving operations in the second discharge voltage mode is less than the number L (for example, the number L or the second number L is set) (S516), the control circuit 320 of the BMS 300 can set the second discharge voltage according to the second discharge voltage mode (S518).

[0108] The second discharge voltage according to the second discharge voltage mode can be set to be lower than the first discharge voltage according to the first discharge voltage mode. For example, the first discharge voltage according to the first discharge voltage mode can be set to about 2.5V, and the second discharge voltage according to the second discharge voltage mode can be set to about 2.2V.

[0109] In one or more embodiments, the second discharge voltage according to the second discharge voltage mode is set lower than the first discharge voltage according to the first discharge voltage mode. Therefore, operation in the second discharge voltage mode can have a greater impact on the lifespan of the battery pack 10 compared to the first discharge voltage mode. Thus, the number of cycles L can be set to a value less than the number of cycles M. For example, the number of cycles M can be set to approximately 25 cycles, and the number of cycles L can be set to approximately 5 cycles.

[0110] The control circuit 320 of the BMS 300 can connect the relay 200 and control the discharge of the battery 100 based on the second discharge voltage according to the second discharge voltage mode (S520). Figure 3 As shown, by reducing the discharge voltage from about 2.5V to about 2.2V, the battery pack 10 can provide additional power, and the electric vehicle can travel a distance corresponding to the additional power.

[0111] Next, the control circuit 320 of the BMS 300 can record the number of emergency driving operations in the second discharge voltage mode. The control circuit 320 of the BMS 300 can increment the number of emergency driving operations in the second discharge voltage mode by 1 (S522).

[0112] In one or more embodiments, if the number of emergency driving operations in the second discharge voltage mode is greater than or equal to the number of times L is set (S516), the control circuit 320 of the BMS 300 may indicate that the battery is depleted (e.g., low battery power) (S524), and may indicate that further driving is difficult, limited, or not permitted.

[0113] Figure 6 This is a block diagram illustrating a drive control device according to one or more embodiments.

[0114] Reference Figure 6The drive control device 600 may include a control circuit 610, a communication circuit 620, and a memory 630.

[0115] The control circuit 610 can be implemented in hardware using at least one of an ASIC, DSP, DSPD, PLD, FPGA, microprocessor, AP, CPU, GPU, and / or other electronic units for performing functions. The control circuit 610 can be any semiconductor device that executes commands of a program stored in memory 630. The control circuit 610 can execute commands of a program stored in memory 630 to perform a specified function. Figures 1 to 5 Describes the drive control operation.

[0116] The communication circuit 620 can perform the communication function between the control circuit 610 and the ECU 20. The communication circuit 620 can send ignition signals, shutdown signals, etc. from the ECU 20 to the control circuit 610, and can also send battery discharge signals, etc. from the control circuit 610 to the ECU 20.

[0117] Such a drive control device 600 can be implemented within the BMS 300, or it can be the BMS 300 itself. In this case, the control circuit 610 and the communication circuit 620 can be respectively located within... Figure 1 The control circuit 320 and communication circuit 330 are shown in the figure.

[0118] According to one or more embodiments, in an emergency driving mode where the battery pack is discharged to its discharge voltage and driving the electric vehicle becomes difficult, additional driving range can be provided by reducing the discharge voltage of the battery pack.

[0119] Embodiments have been disclosed herein, and although specific terminology has been used, it is used and interpreted in a general and descriptive sense only and not for limiting purposes. In some instances, as will be readily understood by one of ordinary skill in the art at the time of filing this application, features, characteristics, and / or elements described in connection with particular embodiments may be used alone or in combination with features, characteristics, and / or elements described in connection with other embodiments, unless expressly stated otherwise. Those skilled in the art will understand that various changes in form and detail may be made without departing from the spirit and scope of this disclosure as set forth in the claims, including its functional equivalents.

Claims

1. A method for controlling an electric vehicle, the electric vehicle using a battery pack comprising individual battery cells as a power source, the method comprising: Receive the first ignition signal; The first discharge voltage mode is activated based on the first ignition signal; The discharge voltage of the battery pack in the first discharge voltage mode is set as the first discharge voltage, which is lower than the normal discharge voltage in the normal driving mode. as well as The battery pack is discharged based on the first discharge voltage.

2. The method according to claim 1, wherein, The steps for discharging the battery pack include: Connect the battery pack to the inverter of the electric vehicle; The battery pack is discharged based on the first discharge voltage; and Increase the cumulative number of operations in the first discharge voltage mode.

3. The method according to claim 2, further comprising: Determine whether the cumulative number of operations in the first discharge voltage mode is less than the number of the first operation; The step of setting the discharge voltage of the battery pack in the first discharge voltage mode includes: When the cumulative number of operations in the first discharge voltage mode is less than the first number, the discharge voltage of the battery pack in the first discharge voltage mode is set to the first discharge voltage.

4. The method according to claim 3, further comprising: When the cumulative number of operations of the first discharge voltage mode is greater than or equal to the first number, it indicates that the battery pack is depleted.

5. The method according to claim 1, further comprising: After the battery pack is discharged based on the first discharge voltage, a second ignition signal is received while the battery pack is not being charged. The second discharge voltage mode is activated based on the second ignition signal; The discharge voltage of the battery pack in the second discharge mode is set as the second discharge voltage, which is lower than the first discharge voltage; as well as The battery pack is discharged based on the second discharge voltage.

6. The method according to claim 5, further comprising: Determine whether the cumulative number of operations in the first discharge voltage mode is less than the number of the first operation; The step of setting the discharge voltage of the battery pack in the first discharge voltage mode includes: When the cumulative number of operations in the first discharge voltage mode is less than the first number, the discharge voltage of the battery pack in the first discharge voltage mode is set to the first discharge voltage.

7. The method according to claim 6, further comprising: Determine whether the cumulative number of operations in the second discharge voltage mode is less than the second number; The step of setting the discharge voltage of the battery pack in the second discharge mode includes: When the cumulative number of operations in the second discharge voltage mode is less than the second number, the discharge voltage of the battery pack in the second discharge voltage mode is set to the second discharge voltage.

8. The method according to claim 7, wherein, The second number is less than the first number.

9. The method according to claim 1, wherein, The anode of the battery cell comprises a mixture of graphite and silicon as the anode active material.

10. The method according to claim 1, wherein, The steps to activate the first discharge voltage mode include: When the remaining capacity of the battery pack is lower than a predetermined threshold, the first discharge voltage mode is activated.

11. An apparatus for controlling the drive of an electric vehicle, the electric vehicle using a battery pack comprising individual battery cells as a power source, the apparatus comprising: The communication circuit is configured to receive the first ignition signal; as well as The control circuit is configured to activate a first discharge voltage mode based on the first ignition signal, connect the battery pack to the inverter of the electric vehicle in the first discharge voltage mode, set the discharge voltage of the battery pack in the first discharge voltage mode as a first discharge voltage, and discharge the battery pack based on the first discharge voltage, wherein the first discharge voltage is lower than the normal discharge voltage of the normal driving mode.

12. The apparatus according to claim 11, wherein, The control circuit is configured to: determine the cumulative number of operations in the first discharge voltage mode, and operate in the first discharge voltage mode when the cumulative number of operations is less than the first number.

13. The apparatus according to claim 11, in, The communication circuit is also configured to receive a second ignition signal while the battery pack is not being charged, after the control circuit discharges the battery pack based on the first discharge voltage. as well as The control circuit is configured to set the discharge voltage of the battery pack in the second discharge mode to a second discharge voltage, and to discharge the battery pack based on the second discharge voltage, wherein the second discharge voltage is lower than the first discharge voltage.

14. The apparatus according to claim 13, wherein, The control circuit is configured to determine whether the cumulative number of operations in the first discharge voltage mode is less than the first number, and when the cumulative number of operations in the first discharge voltage mode is less than the first number, to set the discharge voltage of the battery pack in the first discharge voltage mode to a first discharge voltage, which is lower than the normal discharge voltage.

15. The apparatus according to claim 14, wherein, The control circuit is configured to determine whether the cumulative number of operations in the second discharge voltage mode is less than the second number, and when the cumulative number of operations in the second discharge voltage mode is less than the second number, to set the discharge voltage of the battery pack in the second discharge voltage mode to the second discharge voltage.

16. The apparatus according to claim 15, wherein, The second number is less than the first number.

17. The apparatus according to claim 11, wherein, The control circuit is also configured to activate a first discharge voltage mode when the remaining capacity of the battery pack is below a predetermined threshold.

18. The apparatus according to claim 11, wherein, The anode of the battery cell comprises a mixture of graphite and silicon as the anode active material.

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