Power supply control device and method

Abstract

The present application relates to a power supply control device and method. The power supply control device includes a switch module connected to a power supply portion of a vehicle and a capacitor unit that stores power output from the power supply portion, and a control portion that monitors a voltage of the capacitor unit and controls operation of the switch module based on the monitoring result, the control portion including a switch driver that outputs a switch control signal that controls operation of the switch module, an analog-digital converter that monitors the voltage of the capacitor unit, and a processor that identifies a deterioration state of the capacitor unit based on the monitoring result and controls a duty ratio of the switch control signal based on the deterioration state of the capacitor unit.

Description

Technical Field

[0001] The disclosed invention relates to a power supply control device and method. Background Technology

[0002] In the modern automotive industry, with the increasing popularity of environmentally friendly vehicles, such as electric vehicles, the application of large-capacity power conversion devices is gradually increasing. These devices include inverters and converters, and inevitably utilize large-capacity electrolytic capacitors.

[0003] In particular, in vehicles such as electric vehicles, the power is typically cut off when the vehicle is parked to minimize the battery's current consumption. Therefore, when the vehicle is restarted, the large-capacity electrolytic capacitors need to be recharged, and properly controlling the resulting surge in charging current (inrush current) is crucial for managing the capacitors' lifespan.

[0004] In the past, to limit such inrush current, power switching elements were connected to separate electrical switches and resistors. This method has the advantage of suppressing excessive current that occurs when charging capacitors, but due to the large series resistance, it takes a long time to fully charge the electrolytic capacitor.

[0005] Such a long charging time is incompatible with the requirements of modern automobiles, which need the system to operate quickly after vehicle start-up (IGN, ignition). Therefore, a new technology is needed to minimize charging time while ensuring the lifespan of electrolytic capacitors. Summary of the Invention

[0006] The problem that the invention aims to solve

[0007] One aspect of the disclosed invention provides a power supply control device and method that monitors the voltage of a large-capacity electrolytic capacitor in real time and controls the operation of a power switching element accordingly, thereby preventing electrical damage caused by excessive initial inrush current.

[0008] One aspect of the disclosed invention provides a power supply control device and method that monitors capacitor degradation in real time, thereby minimizing charging time while ensuring the lifespan of the electrolytic capacitor.

[0009] Methods for solving problems

[0010] One aspect of the disclosed invention includes a power supply control device comprising: a switching module connected to a power supply unit of a vehicle and a capacitor unit storing power output from the power supply unit; and a control unit that monitors the voltage of the capacitor unit and controls the operation of the switching module based on the monitoring results. The control unit includes: a switch driver that outputs a switching control signal controlling the operation of the switching module; an analog-to-digital converter that monitors the voltage of the capacitor unit; and a processor that identifies a degradation state of the capacitor unit based on the monitoring results and controls the duty cycle of the switching control signal based on the degradation state of the capacitor unit.

[0011] When power is supplied from the power supply unit, the processor identifies the deterioration state of the capacitor cell based on the increase in the time it takes for the capacitor cell to reach the target voltage relative to a preset reference time.

[0012] The aforementioned switch module includes a first switch unit, which controls the power supply of the power supply unit based on the aforementioned switch control signal.

[0013] The aforementioned switch module also includes a resistor voltage divider circuit, which controls the voltage of the aforementioned switch control signal.

[0014] The aforementioned resistor divider circuit includes a first resistor connected to the gate terminal of the first switching unit, a second resistor connected in parallel with the first resistor, and a second switching unit.

[0015] When the second switching unit is in the ON state, the resistor divider circuit identifies the gate voltage of the first switching unit based on a preset ratio.

[0016] The processor controls the operation of the second switching unit for each charging interval set for the capacitor unit to control the gate voltage.

[0017] In the first charging interval, the processor controls the second switching unit to turn on, thereby reducing the gate voltage to adjust the voltage of the capacitor unit. In the second charging interval, the processor controls the second switching unit to turn off, thereby increasing the gate voltage to adjust the voltage of the capacitor unit.

[0018] The first charging range is set as the range where the charging amount of the capacitor unit is less than a preset charging ratio, and the second charging range is set as the range where the charging amount of the capacitor unit is greater than or equal to the preset charging ratio.

[0019] If the degradation of the capacitor cell exceeds a reference value, the processor outputs a warning signal.

[0020] It also includes an inverter that converts the power output from the power supply unit to supply the motor installed in the vehicle. When the inverter malfunctions, the processor controls the operation of the switching module to cut off the power supply to the power supply unit.

[0021] Invention Effects

[0022] According to one aspect of the disclosed invention, the voltage of a large-capacity electrolytic capacitor is monitored in real time and the operation of a power switching element is controlled accordingly, thereby preventing electrical damage caused by excessive initial inrush current.

[0023] According to one aspect of the disclosed invention, the degradation of a capacitor is monitored in real time, minimizing charging time while ensuring the lifespan of the electrolytic capacitor. Attached Figure Description

[0024] Figure 1 This is a schematic diagram illustrating the structure of a vehicle including a power supply control device according to one embodiment of the disclosed invention.

[0025] Figure 2 This is a diagram illustrating the circuit structure of a vehicle including a power supply control device according to an embodiment of the disclosed invention.

[0026] Figure 3 This is a diagram illustrating the circuit structure of the switching module of a power supply control device according to an embodiment of the disclosed invention.

[0027] Figure 4 This is a graph illustrating a method for monitoring the deterioration state of a capacitor cell according to an embodiment of the disclosed invention.

[0028] Figure 5 This is a timing diagram illustrating the control method of the switching module for each charging zone of a capacitor cell in one embodiment of the disclosed invention.

[0029] Figure 6 This is a sequence diagram illustrating a power supply control method according to an embodiment of the disclosed invention.

[0030] Figure 7 This is a sequence diagram illustrating the control mode of each charging interval of a power supply control method according to an embodiment of the disclosed invention.

[0031] (Symbol Explanation)

[0032] 1: Vehicle; 100: Power supply unit; 200: Power supply control device; 210: Switching module; 211: First switching unit; 212: Resistor voltage divider circuit; 213: Second switching unit; 220: Control unit; 221: Switching driver; 222: Analog-to-digital converter; 223: Processor; 224: Memory; 230: Inverter; 300: Motor; 400: Capacitor unit. Detailed Implementation

[0033] Throughout this specification, the same symbols denote the same constituent elements. This specification does not describe all the elements of the embodiments; descriptions of content that is general in the technical field to which the disclosed invention pertains or that is repeated between embodiments are omitted. Terms such as "part," "module," "component," and "block" as used in the specification can be implemented in software or hardware. According to embodiments, multiple "parts, modules, components, and blocks" can be implemented as a single constituent element, or a single "part," "module," "component," and "block" can include multiple constituent elements.

[0034] Throughout the instruction manual, when referring to a part as being "connected" to other parts, this includes not only direct connections but also indirect connections, including connections via wireless communication networks.

[0035] Furthermore, when it is mentioned that a certain part "includes" a certain element, unless there is a particularly contrary statement, it does not mean that other elements are excluded, but rather that other elements may also be included.

[0036] Throughout the instruction manual, when referring to a component being "on" other components, this includes not only cases where the component is connected to other components, but also cases where other components exist between the two components.

[0037] The terms "first" and "second" are used to distinguish one constituent element from other constituent elements, and the terms do not limit the constituent elements.

[0038] Unless otherwise specified in the text, the singular form can mean multiple.

[0039] The identification symbols used in each step are for illustrative purposes only and do not indicate the order of the steps. If a specific order is not explicitly stated in the text, the steps may be performed in a different order than that explicitly stated.

[0040] The working principle and embodiments of the disclosed invention will now be described with reference to the accompanying drawings.

[0041] Figure 1 This is a schematic diagram illustrating the structure of a vehicle including a power supply control device according to one embodiment of the disclosed invention. Figure 2 This is a diagram illustrating the circuit structure of a vehicle including a power supply control device according to one embodiment of the disclosed invention. Figure 3 This is a diagram illustrating the circuit structure of the switching module of a power supply control device according to an embodiment of the disclosed invention. Figure 4 This is a graph used to illustrate a method for monitoring the degradation state of a capacitor stage according to an embodiment of the disclosed invention. Figure 5 This is a timing diagram illustrating the control method of the switching module for each charging zone of a capacitor cell in one embodiment of the disclosed invention.

[0042] Reference Figure 1 The vehicle 1 of one embodiment of the disclosed invention includes a power supply unit 100, a power supply control device 200, a motor 300, and a capacitor unit 400.

[0043] The power supply unit 100 includes a battery that supplies the power required for driving the vehicle 1. For example, the power supply unit 100 includes a battery that outputs a voltage of about 12V or higher. However, the structure of the power supply unit 100 is not limited to this.

[0044] The power supply control device 200 supplies power from the power supply unit 100 to at least one of the motor 300 and the capacitor unit 400. In this regard, the power supply control device 200 includes a switching module 210, a control unit 220, and an inverter 230.

[0045] The switching module 210 is disposed between the power supply unit 100 and the capacitor unit 400 to control the power supply. Specifically, the switching module 210 performs a pre-charging function to limit the initial inrush current flowing into the capacitor unit 400 and a fail-safe function to cut off the power supply when the inverter 230 malfunctions, based on the control of the control unit 220.

[0046] The control unit 220 monitors the voltage of the capacitor unit 400 and controls the operation of the switching module 210 based on the monitoring results. The control unit 220 includes a switch driver 221, an analog-to-digital converter 222, a processor 223, and a memory 224.

[0047] The switch driver 221 outputs a switch control signal that controls the operation of the switch module 210 according to the control of the processor 223. Here, the switch driver 221 generates and outputs a switch control signal in the form of pulse width modulation (PWM). The switch control signal activates the switch module 210 in an on / off manner, allowing the current from the power supply to flow freely between the power supply unit 100 and at least one of the motor 300 and capacitor unit 400, depending on the resolution. In this way, the switch driver 221 controls the operation of the switch module 210, so that the power output from the power supply unit 100 is supplied to at least one of the motor 300 and capacitor unit 400.

[0048] The analog-to-digital converter 222 monitors the voltage of the capacitor unit 400 in real time, converts it into a digital signal, and then transmits it to the processor 223.

[0049] One or more processors 223 are provided on the control unit 220. The processor 223 generates a pulse width modulation (PWM) pattern for turning the switch module 210 on / off. Furthermore, when power is supplied from the power supply unit 100, the processor 223 calculates the increase in the time it takes for the capacitor cell 400 to reach the target voltage relative to a preset reference time, and identifies the degradation state of the capacitor cell based on the calculated increase. The processor 223 will be described in detail below.

[0050] One or more memories 224 are provided on the control unit 220. The memories 224 store or save programs and data used to control the operation of structures included in the power supply control device 200. For example, the memories 224 store the initial charging time reference value of the capacitor unit 400, a PWM duty cycle mapping table for each degradation state, thresholds for judging current imbalance in the inverter 230, the system operation history and fault records of the vehicle 1, and voltage and current thresholds for implementing various protection functions. Such data stored in the memories 224 is periodically updated to reflect changes in the system state, and is particularly used for analyzing the degradation progress of the capacitor unit 400.

[0051] The memory 224 provides the processor 223 with stored programs and data, and stores temporary data generated during the operation of the processor 223. For example, the memory 224 includes volatile memories such as S-RAM (Static Random Access memory) and D-RAM (Dynamic Random Access Memory), and non-volatile memories such as ROM (Read Only Memory), EPROM (Erasable Programmable Read Only Memory), and flash memory.

[0052] The motor 300 receives power from the inverter 230 of the power supply control device 200, converts the power to generate power for driving the vehicle 1. The motor 300 can be a three-phase permanent magnet synchronous motor (PMSM) or an induction motor, etc.

[0053] The motor 300 is driven by converting the DC power supplied from the capacitor unit 400 into three-phase AC power via the inverter 230. As a core component determining the vehicle's speed, torque, and energy efficiency, the motor 300 exhibits stable and efficient performance thanks to the precise electrical control of the power supply control device 200.

[0054] The capacitor unit 400, serving as a high-capacity load, consists of DC link capacitors that temporarily store power output from the power supply unit 100. In this regard, the capacitor unit 400 includes multiple electrolytic capacitors. The capacitor unit 400 supplies power for the stable operation of the inverter 230.

[0055] Reference Figure 2 and Figure 3 The switching module 210 includes a first switching unit 211 and a resistor voltage divider circuit 212.

[0056] The first switching unit 211 controls the electrical connection between the power supply unit 100 and the capacitor unit 400 according to the switching control signal. In this regard, in one embodiment of the disclosed invention, the first switching unit 211 may be implemented by various types of power semiconductor elements.

[0057] The first switching unit 211 includes at least one of the following: a high-voltage FET (Field Effect Transistor), an IGBT (Insulated Gate Bipolar Transistor), an SCR (Silicon Controlled Rectifier), a GTO (Gate Turn-Off Thyristor), an MCT (MOS Controlled Thyristor), an SJ-MOSFET (Super Junction MOSFET), and a SiC MOSFET (Silicon Carbide MOSFET).

[0058] For example, the first switching unit 211 can be implemented as a SiC (Silicon Carbide) MOSFET, which has the advantage of minimizing switching losses through low on-resistance and high-speed switching characteristics. In addition, SiC MOSFETs have high breakdown voltage characteristics, so they can operate stably in high-voltage systems above approximately 48V.

[0059] The gate drive circuit of the first switching unit 211 turns the first switching unit 211 on or off based on the switching control signal of the switch driver 221. In this regard, the gate resistance value of the gate drive circuit is selected to an appropriate value to limit abrupt changes (di / dt) during on / off. Additionally, to reduce noise, a ceramic capacitor of approximately 0.1 μF is connected in parallel to the gate-source terminals as a bypass capacitor. To protect against overvoltage at the gate terminals, a protection circuit utilizing a Zener diode can be configured, and an active turn-off path is provided via a Miller clamp circuit to prevent parasitic conduction.

[0060] The resistor divider circuit 212 includes a first resistor R1 connected to the gate terminal of the first switching unit 211, a second resistor R2 connected in parallel with the first resistor R1, and a second switching unit 213. Here, the first resistor R1 and the second resistor R2 have the same resistance value. Additionally, the second switching unit 213 includes a small-signal FET that handles low current. However, the structure of the resistor divider circuit 212 can be modified in various ways. For example, different gate voltage reduction ratios can be set to adjust the ratio of the resistance values ​​of the first resistor R1 and the second resistor R2. Furthermore, a resistor divider circuit 212 with three or more stages can be constructed to more finely control the gate voltage.

[0061] Reference Figure 4This illustrates a method for monitoring the deterioration state of capacitor cell 400.

[0062] Figure 4 The horizontal axis represents time, and the vertical axis represents the voltage of capacitor cell 400. Additionally, Figure 4 The solid line A represents the charging curve of capacitor unit 400 in its initial state, and the dashed line B represents the charging curve of capacitor unit 400 in its deteriorated state.

[0063] The processor 223 can detect the time it takes for the voltage of the capacitor unit 400 to reach a target voltage (e.g., 90% of the battery voltage) when power is supplied from the power supply unit 100. If the detected time increases by a set ratio (e.g., 10%) or more relative to a preset reference time, the processor 223 can identify that the capacitor unit 400 has deteriorated (deteriorated state).

[0064] The processor 223 controls the gate voltage of the first switching unit 211 by controlling the operation of the second switching unit 213 according to each charging interval of the capacitor unit 400.

[0065] Reference Figure 5 The charging process of capacitor unit 400 can be divided into a first charging interval T1 and a second charging interval T2.

[0066] The first charging interval T1 can be set as the initial charging interval where the charge of the capacitor unit 400 is lower than a preset charging ratio (e.g., about 50%).

[0067] In order to effectively limit the initial inrush current flowing into the capacitor unit 400 in the first charging interval T1, the processor 223 can control the switching module 210 using a dual control method that combines hardware control and software control.

[0068] Specifically, according to the hardware control method, the processor 223 uses a resistor divider circuit 212 to control the gate voltage. During the first charging interval T1, the processor 223 controls the second switching unit 213 to be in the conducting state. When the second switching unit 213 is in the conducting state, voltage is distributed through the first resistor R1 and the second resistor R2, thereby reducing the voltage applied to the gate terminal of the first switching unit 211.

[0069] Here, the first resistor R1 and the second resistor R2 have the same resistance value (e.g., 10kΩ), thereby reducing the gate voltage to approximately half the level of the input voltage. By reducing the gate voltage in this way, the conduction rate of the first switching unit 211 can be reduced, thus effectively limiting the initial inrush current in hardware.

[0070] According to the software control method, the processor 223 can control the duty cycle of the switch control signal. For example, in the first charging interval T1, the processor 223 controls the switch driver 221 to generate a PWM signal with a duty cycle of about 30% or less. By controlling the PWM with such a low duty cycle, the on / off time of the first switching unit 211 can be controlled, thereby limiting the average current supplied to the capacitor unit 400.

[0071] Thus, by combining gate voltage control and PWM duty cycle control in a dual control method, the power supply control device 200 of one embodiment of the disclosed invention can more stably and effectively limit the initial inrush current even in high-voltage battery systems of approximately 48V and above. In particular, the hardware control and software control work complement each other, thereby improving the reliability of current limiting.

[0072] The second charging interval T2 can be set as a later charging interval where the charging amount of capacitor unit 400 is greater than or equal to a preset charging ratio (e.g., 50%). In the second charging interval T2, the risk of initial inrush current is reduced, so processor 223 can switch the second switching unit 213 to the off state. As a result, the gate voltage of the first switching unit 211 returns to its normal level, improving the conduction efficiency.

[0073] Here, when the second switching unit 213 is switched to the off state, no voltage drop will occur due to the resistor voltage divider circuit 212, so the output voltage of the switch driver 221 is directly applied to the gate terminal of the first switching unit 211.

[0074] The processor 223 adaptively adjusts the PWM duty cycle according to the degradation state of the capacitor unit 400. Specifically, as the degradation of the capacitor unit 400 progresses, the processor 223 gradually reduces the PWM duty cycle of the switching control signal to limit the charging current.

[0075] For example, the processor 223 sets the frequency of the PWM signal to approximately 20kHz, thereby avoiding audible frequency bands while maintaining appropriate switching losses. In addition, the processor 223 controls the PWM duty cycle to different duty cycles depending on the charging range and degradation state of the capacitor unit 400, and in particular, in the first charging range T1, the duty cycle is limited to approximately 30% or less to limit the initial inrush current.

[0076] When the processor 223 supplies power from the power supply unit 100, it detects the charging time of the capacitor unit 400, compares the detected charging time with the set time reference value, and identifies and classifies the deterioration state based on the difference.

[0077] For example, if the increase in charging time is less than about 10% and the degradation is not detected, the processor 223 can maintain the duty cycle of the switch control signal at about 70% to 90%. Furthermore, in a first degradation state (initial degradation state) where the increase in charging time is more than about 10% but less than about 20%, the processor 223 can reduce the duty cycle of the switch control signal to about 70%. Additionally, in a second degradation state (gradual degradation state) where the increase in charging time is more than about 20% but less than about 30%, the processor 223 reduces the duty cycle of the switch control signal to about 50%. Finally, in a third degradation state (severe degradation state) where the increase in charging time is more than about 30%, the processor 223 limits the duty cycle of the switch control signal to about 30% or less and outputs a warning signal.

[0078] Re-reference Figure 2 The power supply control device 200 drives the motor 300 via the inverter 230. In addition, the power supply control device 200 can detect abnormalities in the inverter 230 and execute fail-safe functions for the safe operation of the vehicle 1.

[0079] Inverter 230 consists of a 3-phase inverter including 6 inverter switches (IT1~IT6). Inverter 230 converts the DC power supplied from capacitor unit 400 into 3-phase AC power to drive motor 300.

[0080] Multiple inverter switches (IT1~IT6) each perform power conversion by performing on / off operations according to the control signals from the processor 223. Each inverter switch (IT1~IT6) receives a pulse-width modulation (PWM) inverter switch control signal to perform the on / off operation. Here, the processor 223 supplies inverter switch control signals to each gate electrode of the multiple inverter switches (IT1~IT6). For example, the processor 223 supplies a pulse width modulation (PWM) first inverter switch control signal to the gate electrode of the first inverter switch IT1, a pulse width modulation (PWM) second inverter switch control signal to the gate electrode of the second inverter switch IT2, a pulse width modulation (PWM) third inverter switch control signal to the gate electrode of the third inverter switch IT3, a pulse width modulation (PWM) fourth inverter switch control signal to the gate electrode of the fourth inverter switch IT4, a pulse width modulation (PWM) fifth inverter switch control signal to the gate electrode of the fifth inverter switch IT5, and a pulse width modulation (PWM) sixth inverter switch control signal to the gate electrode of the sixth inverter switch IT6.

[0081] At this point, if any of the multiple inverter switches (IT1~IT6) malfunctions, the balance of the three-phase AC circuit will be disrupted, and the motor 300 will be abnormally driven, which could cause fatal damage to the entire vehicle 1. To address this, the processor 223 can monitor the normal operation of the inverter 230 in real time.

[0082] Specifically, the processor 223 detects the current flowing in each phase (U phase, V phase, W phase) of the inverter 230 to confirm the balance of the phase currents. During normal operation, the three-phase currents have a phase difference of approximately 120 degrees and flow at a constant magnitude. However, if at least one of the inverter switches (IT1~IT6) malfunctions, the current in a specific phase may abnormally increase or decrease. For example, if the current in a specific phase differs by more than 20% compared to the other phases, or if the phase difference deviates by approximately 120 ± 10 degrees, the processor 223 determines that the inverter 230 is malfunctioning.

[0083] In addition, the processor 223 receives feedback on the on / off states of the various inverter switches (IT1~IT6) to determine whether to perform normal switching operations according to the control signals. Furthermore, the processor 223 can also monitor whether the temperature of the inverter 230 exceeds a set threshold using a temperature sensor.

[0084] When the processor 223 senses an abnormality in the inverter 230 during such monitoring, it immediately executes a response operation. First, the processor 223 controls the first switching unit 211 to the off state via the switch driver 221, thereby cutting off the power supply from the power supply unit 100 to the capacitor unit 400. This is to minimize damage to the vehicle 1 by cutting off the additional power supply. In addition, the processor 223 stops the drive of the inverter 230, thereby terminating the operation of the motor 300, and outputs a warning signal informing the driver of the abnormality.

[0085] The power supply control device 200 of one embodiment of the disclosed invention senses various abnormal states and performs response functions.

[0086] The control unit 220 of the power supply control device 200 senses the overvoltage state of the capacitor unit 400. The processor 223 continuously monitors the voltage of the capacitor unit 400 via the analog-to-digital converter 222, and identifies an overvoltage state when the voltage exceeds a set upper limit threshold. When an overvoltage is sensed, the first switching unit 211 is immediately disconnected to cut off the power supply, and the system remains on standby until the voltage of the capacitor unit 400 drops to a safe range.

[0087] For example, when the voltage of capacitor cell 400 exceeds approximately 110% of the rated voltage, analog-to-digital converter 222 determines this as an overvoltage condition and notifies processor 223 of the determination result.

[0088] In addition, when the voltage of the power supply unit 100 drops below a set lower limit, the processor 223 protects at least one of the power supply control device 200, motor 300 and capacitor unit 400 through a low voltage sensing function.

[0089] The power supply control device 200 can sense the performance degradation caused by the deterioration of the capacitor unit 400. As explained above, the deterioration state is identified by the increase in charging time, and when severe deterioration is sensed, a warning signal is output to inform the driver that the vehicle 1 needs to be repaired.

[0090] The power supply control device 200 senses abnormal operation of the inverter 230. When it senses imbalance of the three-phase current, malfunction of the switching element, overheating, etc., the power supply control device 200 executes protection operations in sequence.

[0091] Specifically, after sensing an anomaly in the inverter 230, the processor 223 immediately switches multiple inverter switches (IT1~IT6) of the inverter 230 to the off state, thereby cutting off the power supply to the motor 300. Then, the processor 223 controls the switch driver 221 to disconnect the first switch unit 211, thereby cutting off the power supply from the power supply unit 100.

[0092] In one embodiment of the disclosed invention, the power supply control device 200 applies the identification results of the deterioration state of the capacitor unit 400 to the formulation of a preventive maintenance plan for the vehicle 1. The processor 223 analyzes the rate of deterioration progression of the capacitor unit 400 to predict future maintenance timing.

[0093] The degradation status monitoring function of the power supply control device 200 can also be applied to the formulation of vehicle preventive maintenance plans. The processor 223 analyzes the rate of degradation progression of the capacitor unit 400 to predict future maintenance times. For example, it calculates the degradation progression trend based on the charging time data of the most recent 10 times, thereby calculating the expected time point when it reaches a severely degraded state. This information is provided to the driver or repair shop so that preventive maintenance can be performed at the appropriate time. For example, the processor 223 calculates the degradation progression trend based on approximately the most recent charging time data, thereby calculating the expected time point when it reaches a severely degraded state. Furthermore, the processor 223 provides information to the driver based on the calculated time point so that preventive maintenance can be performed at the appropriate time.

[0094] The power supply control device 200 of one embodiment of the disclosed invention effectively limits the initial inrush current by combining hardware current limiting and software current limiting in a dual control method. In particular, stable charging is possible even in high-voltage battery systems of approximately 48V and above. Hardware current limiting is provided by gate voltage control via the resistor divider circuit 212, while software current limiting is provided by PWM duty cycle control. This dual control method enables more stable and reliable current limiting compared to a single control method.

[0095] Furthermore, in one embodiment of the disclosed invention, the power supply control device 200 monitors the degradation state of the capacitor cell 400 in real time, thereby adaptively controlling the charging current and extending the capacitor's lifespan. Specifically, the PWM duty cycle is adjusted in stages according to the degree of degradation, thereby delaying the progression of degradation and providing warning signals for preventative maintenance before severe degradation occurs.

[0096] Furthermore, in one embodiment of the disclosed invention, the power supply control device 200 can perform both pre-charging and fail-safe functions by a single first switching unit 211. During pre-charging operation, the initial charging current is limited by gate voltage control and PWM duty cycle control. In the event of an inverter 230 malfunction, the power supply is cut off to protect the system. Thus, by implementing both functions with a single switching element, the number of components can be reduced, and the system simplified.

[0097] Furthermore, the power supply control device 200 of one embodiment of the disclosed invention divides the charging interval into a first charging interval and a second charging interval and applies an optimal control strategy to each interval, thereby ensuring both safety and efficiency. During initial charging, safety is ensured through enhanced current limiting, and thereafter efficiency is ensured through adaptive control based on deterioration conditions.

[0098] Below, refer to Figure 6 The power supply control method of one embodiment of the disclosed invention will be described.

[0099] Figure 6 This is a sequence diagram illustrating a power supply control method according to an embodiment of the disclosed invention. Figure 7 This is a sequence diagram illustrating the control mode of each charging interval of a power supply control method according to an embodiment of the disclosed invention.

[0100] Here, by reference Figures 1 to 5 The power supply control method executed by the power supply control device will be explained.

[0101] Reference Figure 6 and Figure 7First, when vehicle 1 is started, processor 223 controls the operation of switch module 210 located between power supply unit 100 and capacitor unit 400 to supply power to capacitor unit 400 (S100).

[0102] In the switching module 210, which includes a first switching unit 211 and a resistor voltage divider circuit 212, the first switching unit 211 controls the electrical connection between the power supply unit 100 and the capacitor unit 400 according to a switching control signal. The first switching unit 211 includes at least one of the following: high-voltage FET (Field Effect Transistor), IGBT (Insulated Gate Bipolar Transistor), SCR (Silicon Controlled Rectifier), GTO (Gate Turn-Off Thyristor), MCT (MOS Controlled Thyristor), SJ-MOSFET (Super Junction MOSFET), and SiCMOSFET (Silicon Carbide MOSFET).

[0103] The first switching unit 211 performs switching operations based on a switching control signal supplied to the gate electrode. For example, the first switching unit 211 is turned on or off based on the gate voltage supplied to the gate electrode. The switch driver 221, which outputs a switching control signal to the first switching unit 211, controls the operation of the switching module 210 according to the control of the processor 223. At this time, the switch driver 221 outputs a pulse width modulation (PWM) switching control signal to the first switching unit 211. The switching control signal activates the switching module 210 in an on or off manner, allowing the current of the power supply to flow freely between the power supply section 100 and at least one of the motor 300 and the capacitor unit 400 according to the resolution. In this way, the switch driver 221 controls the operation of the switching module 210 so that the power output from the power supply section 100 is supplied to at least one of the motor 300 and the capacitor unit 400.

[0104] Next, the control unit 220 monitors the voltage of the capacitor unit 400 via the analog-to-digital converter 222 (S200).

[0105] Specifically, the analog-to-digital converter 222 monitors the voltage of the capacitor cell 400. The analog-to-digital converter 222 monitors the voltage of the capacitor cell 400 in real time and converts it into a digital signal before transmitting it to the processor 223. In this regard, the analog-to-digital converter 222 includes a voltage detection circuit to accurately monitor the voltage of the capacitor cell 400. For example, the voltage detection circuit is configured by connecting approximately 100kΩ of resistor on the high-voltage side and approximately 10kΩ of resistor on the low-voltage side in series, with each resistor set to have a precision of approximately 0.1% and a temperature coefficient of approximately 25ppm / ℃. By setting such a voltage division ratio, the analog-to-digital converter 222 optimizes the input voltage range for accurate monitoring of the voltage of the capacitor cell 400.

[0106] In addition, the analog-to-digital converter 222 incorporates a low-pass filter with a cutoff frequency set to approximately 10kHz to eliminate high-frequency noise in order to remove noise from the voltage detection circuit. Furthermore, the analog-to-digital converter 222 uses shielded cables to prevent the inflow of electromagnetic noise, and the high-voltage circuitry and signal circuitry are physically separated during the design of the printed circuit board, thereby minimizing interference.

[0107] The voltage is detected by analog-to-digital converter 222 in the following manner. First, the sampling frequency of analog-to-digital converter 222 is set to more than 10 times the PWM frequency to fully capture voltage changes. The detected digital value is processed by a moving average filter to remove the influence of instantaneous noise, and the filtered value is transmitted to processor 223 for determining the charging state and deterioration state of capacitor unit 400.

[0108] The power supply control device 200, which includes such an analog-to-digital converter 222, enables more stable and precise control and also ensures robustness against noise.

[0109] The processor 223 identifies the degradation state of the capacitor cell 400 based on the monitoring results (S300). Specifically, the processor 223 detects the time it takes for the voltage of the capacitor cell 400 to reach the target voltage and compares it with a preset reference time. When power is supplied from the power supply unit 100, the processor 223 calculates the increase in the time it takes for the capacitor cell 400 to reach the target voltage relative to the preset reference time, and identifies the degradation state of the capacitor cell 400 based on the calculated increase. For example, if the detected time increases by a set ratio (e.g., 10%) or more relative to the preset reference time, the processor 223 can identify that the capacitor cell 400 has degraded (degraded state).

[0110] Next, the processor 223 controls the operation of the switch module 210 based on the monitoring results. In particular, the processor 223 controls the duty cycle of the switch control signal (S400) according to the deterioration state and charging range of the capacitor unit 400.

[0111] Regarding the control method of each charging zone in one embodiment of the disclosed invention, different control methods may be applied to each other depending on the amount of charge in the capacitor unit 400.

[0112] First, the charging amount of capacitor unit 400 is compared with a preset charging ratio (e.g., 50%) to distinguish the charging intervals (S410).

[0113] If the charge level of capacitor cell 400 is less than a preset charging ratio (e.g., 50%) in the first charging interval T1, enhanced control (S420) to limit the initial inrush current can be executed. Processor 223 controls the second switching unit 213 to be in the on state, reducing the gate voltage of the first switching unit 211 to approximately half the normal voltage level. Simultaneously, processor 223 limits the duty cycle of the switching control signal to below 30%. Through this dual control method, processor 223 can effectively limit excessive inrush current that may occur during initial charging, even in high-voltage systems above 48V.

[0114] If the charge level of capacitor cell 400 exceeds a preset charging ratio, the system transitions to a second charging range T2 (S430). In this range, the risk of initial inrush current decreases, and therefore processor 223 switches second switch cell 213 to an off state to restore the gate voltage of first switch cell 211 to a normal level. Processor 223 can adaptively adjust the duty cycle according to the deterioration state of capacitor cell 400.

[0115] For example, in a normal state where no degradation is detected, the processor 223 maintains the duty cycle of the switching control signal at approximately 70% to 90%. In an initial degradation state where the charging time increases by approximately 10%, the processor reduces the duty cycle of the switching control signal to approximately 70%. In a gradual degradation state where the charging time increases by approximately 20%, the processor reduces the duty cycle of the switching control signal to approximately 50%. In a severe degradation state where the charging time increases by approximately 30% or more, the processor limits the duty cycle of the switching control signal to approximately 30% or less and outputs a warning signal. According to a power supply control method of one embodiment of the disclosed invention, the degradation of the capacitor unit 400 is delayed by adaptive duty cycle control, extending its lifespan while achieving stable system operation.

[0116] On the other hand, the disclosed embodiments can be implemented as a recording medium storing computer-executable instructions. The instructions can be stored as program code, which, when executed by a processor, generates a program module to perform the operations of the disclosed embodiments. The recording medium can be implemented as a computer-readable recording medium.

[0117] Computer-readable recording media include all types of recording media that store computer-readable instructions. Examples include ROM (Read Only Memory), RAM (Random Access Memory), magnetic tape, hard disk, flash memory, and optical data storage devices.

[0118] Device-readable storage media may be provided in the form of non-transitory storage media. Here, "non-transitory" simply means that the storage medium is a tangible device, excluding signals (e.g., electromagnetic waves), and this term does not distinguish between cases where data is stored semi-permanently and cases where data is temporarily stored on the storage medium. For example, "non-transitory storage media" may include buffers for temporarily storing data.

[0119] The disclosed embodiments have been described above with reference to the accompanying drawings. Those skilled in the art can implement the present invention in different forms than the disclosed embodiments without changing the technical concept or essential features of the invention. The disclosed embodiments are illustrative examples, and the present invention is not limited thereto.

Claims

1. A power supply control device, comprising: A switching module that connects the vehicle's power supply unit and a capacitor unit that stores the power output from the power supply unit. and The control unit monitors the voltage of the capacitor cells and controls the operation of the switching module based on the monitoring results. The aforementioned control unit includes: A switch driver that outputs a switch control signal to control the operation of the aforementioned switch module; An analog-to-digital converter that monitors the voltage of the aforementioned capacitor cell; and The processor identifies the degradation state of the capacitor cell based on the monitoring results and controls the duty cycle of the switch control signal based on the degradation state of the capacitor cell.

2. The power supply control device according to claim 1, wherein, When power is supplied from the power supply unit, the processor identifies the deterioration state of the capacitor cell based on the increase in the time it takes for the capacitor cell to reach the target voltage relative to a preset reference time.

3. The power supply control device according to claim 1, wherein, The aforementioned switch module includes a first switch unit, which controls the power supply of the power supply unit based on the aforementioned switch control signal.

4. The power supply control device according to claim 3, wherein, The aforementioned switch module also includes a resistor voltage divider circuit, which controls the voltage of the aforementioned switch control signal.

5. The power supply control device according to claim 4, wherein, The aforementioned resistor divider circuit includes a first resistor connected to the gate terminal of the first switching unit, a second resistor connected in parallel with the first resistor, and a second switching unit.

6. The power supply control device according to claim 5, wherein, When the second switching unit is in the ON state, the resistor divider circuit identifies the gate voltage of the first switching unit based on a preset ratio.

7. The power supply control device according to claim 6, wherein, The processor controls the operation of the second switching unit for each charging interval set for the capacitor unit to control the gate voltage.

8. The power supply control device according to claim 7, wherein, During the first charging interval, the processor controls the second switching unit to turn on, thereby reducing the gate voltage to adjust the voltage of the capacitor unit. During the second charging interval, the processor controls the second switching unit to open, thereby increasing the gate voltage to adjust the voltage of the capacitor unit. The first charging range is set as the range where the charging amount of the capacitor unit is less than a preset charging ratio. The second charging range is set as the range where the charging amount of the capacitor unit is above a preset charging ratio.

9. The power supply control device according to claim 3, wherein, If the degradation of the capacitor cell exceeds a reference value, the processor outputs a warning signal.

10. The power supply control device according to claim 1, wherein, The power supply control device also includes: An inverter converts the power output from the aforementioned power supply unit and supplies it to the motor installed in the aforementioned vehicle. When the inverter malfunctions, the processor controls the operation of the switching module to cut off the power supply to the power supply unit.

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