current control module

Abstract

A current control module, a battery management system including the control module, a method for controlling inrush current, and a computer-readable medium for performing the method are provided. The current control module is used to control inrush current generated by an electrical connection from a startup battery to an electrical load, wherein a metal-oxide-semiconductor field-effect transistor (MOSFET) is electrically connected between the battery and the electrical load, and the effective drain-source resistance (Ro) of the MOSFET is... DS The control module is configured to: receive a current sensing signal indicating the current between the battery and the electrical load; compare the current sensing signal with a threshold level; and adjust a control signal for a MOSFET in response to the comparison to control the MOSFET's RDS such that the current sensing signal is shifted toward or below the threshold level or maintained below the threshold level.

Description

[0001] Cross-references to related applications

[0002] This case claims priority and interest in GB 2319816.1, filed on December 21, 2023 (2023.12.21), the contents of which are incorporated herein by reference in their entirety. Technical Field

[0003] The present invention relates to a current control module for controlling inrush current generated by an electrical connection from a starting battery to an electrical load; a battery management system including the control module; a method for controlling the inrush current; and a computer-readable medium for performing the method. Background Technology

[0004] Typically, when a battery is initially connected to a load (or source) such as a device to be powered by the battery or a charger for charging the battery, the input capacitance of the load / battery is initially discharged. This causes an initial high current surge, known as inrush current, to be generated between the battery and the load / source. This can potentially damage the battery and / or the load. Existing electronic devices incorporate methods and circuits to reduce the potentially damaging effects of inrush current, and existing battery systems can incorporate circuitry to protect against short circuits.

[0005] Recent innovations in battery technology have resulted in batteries that allow for faster charging and discharging than conventional batteries. These fast-charging (discharging) batteries typically have lower internal impedance than conventional batteries, which can lead to higher peak inrush currents when connected to a load or source. In some cases, these much higher inrush currents can damage the battery or the connected load. Moreover, the inventors have observed that conventional short-circuit protection in batteries may be too slow to react or completely disconnect the battery from the load / source in the presence of these high inrush currents.

[0006] US 6067239 discloses a smooth circuit that can operate at high temperatures even when the internal resistance of a capacitor changes with temperature. It incorporates a MOSFET connected in series with a capacitor and fed by a voltage divided by a resistor and a thermistor. The thermistor reduces the voltage input to the MOSFET, thus reducing the Ro of the MOSFET. DS This is increased during the connection process. However, thermistors typically have a slow response time to changing temperatures. Therefore, controlling the MOSFET in this way based on temperature can result in hysteretic control of inrush currents, which can lead to damaging current spikes, especially when used with low-impedance batteries.

[0007] EP 3080540 discloses a circuit breaker with a switch that automatically disconnects in response to a fault event. The switch incorporates a FET connected in series with a bimetallic strip. The bimetallic strip deforms by different amounts at different temperatures, and therefore, if the circuit begins to overheat, it will physically disconnect the FET. The bimetallic strip's response time to changing temperatures can be slow, and in response to surge currents, it may cause the connection between the battery and the load to be prematurely damaged.

[0008] The present invention was designed based on the above considerations. Summary of the Invention

[0009] In a general sense, the present invention provides an apparatus for controlling a surge current by gradually adjusting a resistance in a feedback loop for a surge current between a battery and a load (or source) until the current reaches a steady state. This is achieved by adjusting the effective drain-source resistance (Ro) of a transistor (such as a MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor)) between the battery and the load. DS ( ) to apply the resistance.

[0010] Using MOSFETs and feedback loops to control inrush current results in faster and more adjustable control of the inrush current. By employing MOSFETs in this way, existing circuitry in the battery management system (BMS) can be adapted to regulate the current, thereby reducing circuit complexity and cost compared to more widely used methods for protecting against high inrush currents.

[0011] Accordingly, the present invention provides a control module for controlling a MOSFET in response to a current signal to adjust the (R) of the MOSFET. DS The MOSFET is controlled to maintain the current sensing signal below an acceptable level. When the battery is connected to a load, the MOSFET is controlled to have a high drain-source on-resistance (R0). DS To prevent high inrush current, and is controlled to have an R value that gradually decreases over time as the connection continues and the inrush current decreases. DS Typically, the controller is configured to operate a feedback loop in which the current-sensing signal is compared to a threshold level and the control signal (which controls the R of the MOSFET) is updated based on the comparison. DS ).

[0012] The present invention also provides a battery management system (BMS) connected to a battery and incorporating a MOSFET controlled to have a high drain-source on-resistance (Ro) when the battery is connected to a load. DSAnd it is controlled to have an R that gradually decreases over time as the connection continues. DS For example, the load may be a device powered by the battery, a device for charging the battery, or some testing equipment.

[0013] A method for controlling surge current and a control algorithm are also provided, the control algorithm being executed by the BMS to control the R of the MOSFET during the connection process between the battery and the load (or source). DS By adjusting the gate voltage (V) of the MOSFET GS Adjustments are made to affect the R. DS The control algorithm can be advantageously implemented on the discharge MOSFET already present in the battery system to reduce additional cost and complexity while still providing the benefits of the invention.

[0014] This invention is advantageous because it provides short-circuit protection while still allowing the battery to perform rapid charging and discharging. Upon initial connection, the increased R of the MOSFET... DS The initial discharge of the battery is reduced, allowing for a relatively rapid initial discharge while avoiding triggering short-circuit protection. No correction to the short-circuit threshold or delay time is required, therefore protection against short circuits at the battery output terminals remains available. Then the MOSFET R... DS The reduction allows for full utilization of fast-charging and fast-discharging battery technologies when the inrush current is reduced to an acceptable level. Consequently, the proposed system can react faster and is more adjustable than existing solutions that rely on temperature sensing or the ability to completely disconnect the battery and load in the presence of high current.

[0015] The present invention is set forth in the appended claims.

[0016] In a first aspect, a current control module is provided for controlling inrush current generated by an electrical connection from a startup battery to an electrical load, wherein a metal-oxide-semiconductor field-effect transistor (MOSFET) is electrically connected between the battery and the load, and the effective drain-source resistance (Ro) of the MOSFET is... DS The control module is configured to: adjust the current between the battery and the electrical load; and receive a current sensing signal indicating the current between the battery and the electrical load; compare the current sensing signal with a threshold level; and adjust a control signal for the MOSFET in response to the comparison to adjust the R of the MOSFET. DSThe control is configured such that the current sensing signal is shifted toward or below the threshold level or is maintained below the threshold level.

[0017] Advantageously, compared to conventional current limiters that may include fixed resistors or NTC (negative temperature coefficient) devices such as thermistors, the control of the MOSFET, which adjusts in response to sensing the current between the battery and the load / source, enables more effective limitation of inrush current, which is applicable and adjusts to the changing current more quickly. Therefore, the control module of the first aspect is particularly suitable for use with low-impedance batteries. Accordingly, by achieving more effective inrush current protection, the likelihood of damage to the battery is reduced, and the battery life can be extended.

[0018] Furthermore, the control module can be configured to continuously compare the current sensing signal with the threshold level and continuously adjust the control signal for the MOSFET in response to the comparison. For example, the drain-source resistance of the MOSFET can be adjusted incrementally (continuously) based on the value of the sensed current. The drain-source resistance of the MOSFET and / or the control signal can be adjusted proportionally to the value of the sensed current. Accordingly, by adjusting the drain-source resistance reactively and gradually based on the sensed current in this manner, the drain-source resistance can be gradually increased and / or decreased until the current reaches a steady state, thus avoiding abrupt changes in the current and / or drain-source resistance that could occur if the MOSFET is controlled to be completely off and on only, or has different values ​​of drain-source resistance not determined based on the sensed current. The following disclosure describes several examples of gate drive circuits for implementing such a scheme, wherein the drain-source resistance of the MOSFET is adjusted reactively and continuously in this manner.

[0019] For example, the control module can be configured to repeatedly execute the receiving step, the comparison step, and the adjustment step to continuously adjust the drain-source resistance based on the sensed current. The repetition can be performed at a predetermined update rate. For example, the predetermined update rate can depend on the processing rate of the control module and / or the update rate of the sensor used to sense the current. The control module can be configured to terminate the repetition when it is determined that the current has reached a steady state and / or the MOSEFT is fully "on," thus indicating that limiting the inrush current is no longer necessary.

[0020] Known methods for managing inrush current using FETs typically focus on switching transistors to a fully "off" state and a fully "on" state, or using different linear mode gate voltages (e.g., using current sensing signals) to control FETs that are not controlled by inrush current.

[0021] For example, US 2019 / 0229527 describes a system for controlling inrush current between a power source and a load. That system uses a transistor to limit the inrush current. However, only a discrete “linear mode” gate voltage is used during charging. This differs from this disclosure, in which the transistor’s internal resistance Rds is reactively and continuously adjusted based on the value of the sensed current (e.g., by adjusting a control signal proportional to the current). This disclosure provides a device in which Rds gradually changes (e.g., ramps up) with changing current, a device not described in US 2019 / 0229527.

[0022] US 2009 / 0189588 also describes using changes in resistance to limit current flow and using pulse generation circuitry to generate control signals. However, the pulse control signals are used to switch a bypass resistor into and out of the circuitry used to limit current, where the switch can be a transistor. Therefore, the transistor switches between a fully "on" state and a fully "off" state, rather than being operated to gradually change the transistor's internal resistance as is currently the case.

[0023] WO 2024 / 019666 describes two MOSFETs connected in series between a battery and a load. The second MOSFET has a bypass resistor connected in parallel. A controller is configured to limit inrush current by controlling the MOSFETs. This arrangement operates by providing a delay between the turn-on time of the first MOSFET and the turn-on time of the second MOSFET, such that the second MOSFET is turned on only after the input capacitance of the load has been charged. Therefore, the transistor also operates only in a fully "on" or fully "off" state.

[0024] These documents do not describe adjusting the control signal for the MOSFET in response to a comparison between current and a threshold to shift the current sensing signal toward or below the threshold level, let alone continuously controlling and adjusting the MOSFET's internal resistance based on the sensed current to provide inrush current control. Nor do these documents describe the specific gate drive circuit illustrated herein.

[0025] The MOSFET can be a high-side MOSFET positioned between the high-side of the load / source and the battery. A high-side MOSFET is preferred because it maintains a permanent ground connection during operation. Furthermore, high-side BMS drives are more common in the market, thus facilitating modifications to existing BMS circuits to include the control module of this invention. However, the techniques discussed herein can also be applied using a low-side MOSFET.

[0026] An electrical load can be an electrical load or source configured to draw current from or supply current to a battery (i.e., for charging). Accordingly, when an electrical load is a current source, it can be considered a "negative electrical load".

[0027] For example, a load can be a device powered by a battery or a second battery (such as an EV battery) used for charging. Therefore, in this example, current can flow from the battery to the load. Alternatively, when the electrical load is a source (i.e., a negative load), it can be a device configured to charge a battery. Therefore, in this example, current can flow from the source to the battery, in which case the battery can be considered the electrical load. The load (or source) can have an input capacitance that causes an initial surge of high inrush current to be drawn from the battery until the input capacitance reaches a charged state.

[0028] The techniques and systems discussed in this article for limiting inrush current can be applied to two examples, unless one of these cases is clearly excluded. Accordingly, the power source and / or load may simply be referred to as a “load” in this article, whereby a load can be interpreted as a load that draws current or as a “negative load” that provides current.

[0029] In general, this disclosure discusses three embodiments of the control module according to the invention, as well as variations on those embodiments for limiting inrush current. Specifically, this disclosure provides: a first embodiment in which a microcontroller is used to adjust the control signal to implement the control module; a second embodiment in which an analog circuit system is used to adjust the control signal to implement the control module; and a third embodiment in which pulse width modulation (PWM) is used to adjust the control signal. However, in each of these three embodiments, a feedback loop is provided in which the current sensing signal is compared with a threshold level, and the control signal is updated based on the comparison.

[0030] The current sensing signal can be a sensed voltage indicating the current flowing between the battery and the load. In other examples, the current sensing signal can be the current itself, or a digital representation of the current received by, for example, a microcontroller (MCU).

[0031] The threshold level can be a voltage level used, for example, to compare with a current-sensing signal using an analog circuit system discussed in more detail below. In other examples, the threshold level can be a threshold current used to limit inrush current. In a further example, the threshold level can be a digital value stored in the memory of the MCU.

[0032] By continuously comparing the current signal with a threshold level, the control of the MOSFET can be dynamically adjusted in the feedback loop, enabling adaptive regulation of the surge current and providing smoother current regulation than existing solutions.

[0033] A metal-oxide-semiconductor field-effect transistor (MOSFET) can be a three-terminal transistor with a gate (G) terminal, a drain (D) terminal, and a source (S) terminal. A MOSFET can have a controllable drain-source resistance (Ro). DS R is typically controlled using a control signal applied to the gate of the MOSFET. DS .

[0034] Any suitable MOSFET can be used. For example, the MOSFET can be an N-channel FET, which is more common in high-power BMS applications. However, in other examples, the MOSFET can be a p-channel FET, where a pull-down resistor can be used to drive the gate of the p-channel MOSFET. However, the techniques and control circuitry discussed in this paper for controlling the MOSFET can be the same in every case.

[0035] An electrical connector can refer to a connection that allows electrical energy to flow between two terminals or nodes. The electrical connectability of two components refers to the situation where two components can be electrically connected (e.g., via conductors such as wires, cables, or traces). These components can be releasably electrically connected.

[0036] The current between the battery and the load can be considered as the current flowing through the electrical connection via the MOSFET. The current can be indicated by a current sensing signal.

[0037] The current sensing signal can be compared to a threshold level. The comparison can be direct or indirect, where the current sensing signal and / or threshold level are converted to comparable units. The threshold value can be selected depending on the battery and load / source. For example, the threshold value can be or correspond to a current value such as 300 A, 250 A, 200 A, 150 A, 100 A, or 50 A.

[0038] The controller can be configured to adjust the control signal for the MOSFET in response to a comparison, so as to adjust the R of the MOSFET. DSThe control is configured to shift the current sensing signal toward or below a threshold level or to maintain it below a threshold level.

[0039] The control module can be configured to turn the R of the MOSFET when the electrical connection from the battery to the electrical load is initiated. DS Set as the initial effective resistance.

[0040] The initial effective resistance can refer to a predetermined resistance. It can be a resistor configured to prevent inrush current from exceeding a threshold value. For example, the R0 of the MOSFET (IRF2805S) used in the simulation examples discussed in this paper... DS The fully on-resistance is 3.6 mΩ and R DS The complete turn-off resistance is several MΩ. Therefore, the initial effective resistance can be R at any point within this range. DS The range can be adjusted according to the current sensing signal so that the current sensing signal is maintained below a threshold level.

[0041] In other examples discussed in this paper, the initial effective resistance may correspond to the average resistance between the “on” resistance and the “off” resistance of the MOSFET when the MOSFET is switched by a PWM signal with a predetermined frequency and duty cycle.

[0042] When current begins to flow between the battery and the load / source, the electrical connection from the battery to the load can be initiated. This can be done either when an electrical connection is formed between the battery and the load / source or in response to the formation of such an connection.

[0043] The control module can be configured as follows:

[0044] When the current sensing signal is higher than the threshold level, the R of the MOSFET will... DS Set as the first effective resistance, and

[0045] When the current sensing signal has decreased below the threshold level, the R of the MOSFET will... DS The resistance is reduced to a second effective resistance, which is lower than the first effective resistance.

[0046] In this context, a current sensing signal “above” a threshold level can be interpreted as meaning that the voltage or value of the current sensing signal is higher than the threshold level.

[0047] The first effective resistor can refer to a predetermined resistor configured to limit inrush current. The predetermined resistor can be configured to regulate the inrush current below a threshold value. For example, the first effective resistor can be the initial effective resistor discussed above.

[0048] The second effective resistance can refer to a predetermined resistance. The second effective resistance is smaller than the first effective resistance. The second effective resistance can be a resistor configured to regulate the current between the battery and the load / source to a value below a threshold. In some examples, the second effective resistance can be configured to be the minimum resistance of the RDS to maximize the current flow between the load / source and the battery during normal operation (i.e., after the inrush current has stabilized to a steady state).

[0049] The second effective resistance can be the "on" resistance of the MOSFET. In other examples, the second effective resistance can be an intermediate resistance lower than the first effective resistance. Accordingly, the effective R... DS It can decrease (gradually or stepwise) as the surge current decreases.

[0050] The effective R of the MOSFET can be controlled by controlling the gate-source voltage used to drive the MOSFET. DS The gate-source voltage of a MOSFET can depend on a control signal. Accordingly, those skilled in the art will understand that a first effective resistance can correspond to a first voltage of the control signal, and a second effective resistance can correspond to a second voltage of the control signal.

[0051] In some cases, when it is determined that the current sensing signal has decreased below a threshold level, the MOSFET can be switched from the first R in a step change. DS Adjusted to the second R DS In other examples, the effective R DS It can gradually decrease as the surge current decreases toward a steady state. The second resistor can be the "on" resistance of the MOSFET (i.e., the resistance that allows the MOSFET to operate in its saturation region).

[0052] The control signal can be configured to make the MOSFET operate in its linear region when the current sensing signal is above a threshold level.

[0053] The linear region can refer to the operating region of the gate-source voltage of a MOSFET, where the MOSFET is between a fully on state and a fully off state. Preferably, the linear region refers to the region where the MOSFET is on and R is effectively off. DS It depends essentially linearly on the gate-source voltage.

[0054] When the MOSFET is operated in its linear region, the effective R of the high-side MOSFET is... DS This can (essentially linearly) depend on the gate-source voltage, thus facilitating fine control of current regulation, which can be adjusted in response to varying inrush currents. In other examples (discussed below), the MOSFET can be switched between on and off states using a PWM signal to adjust the effective R.DS .

[0055] The control signal can be an analog voltage that varies between a minimum voltage and a maximum voltage, wherein the minimum voltage corresponds to the maximum R of the MOSFET. DS And the maximum voltage corresponds to the minimum R of the MOSFET. DS Accordingly, in this example, the control signal can be adjustable between a minimum analog voltage and a maximum analog voltage. Therefore, the minimum voltage can correspond to the maximum R of the MOSFET. DS And the maximum voltage can correspond to the minimum R of the MOSFET. DS When the MOSFET has a maximum R DS When the MOSFET has a minimum R0, it can be in the "off" state. DS When the MOSFET is in the "on" state, it can operate in its saturation region.

[0056] The control signal can depend on (and optionally be proportional to) the difference between the current sensing signal and a threshold level. For example, the control signal can be generated by amplifying the difference between the current sensing signal and the threshold level (e.g., using an analog circuit system) or by subtracting the threshold level from the current sensing signal (e.g., in software).

[0057] In one implementation, the current control module may include a microcontroller and a digital-to-analog converter (DAC). The microcontroller may be configured to receive the current sensing signal, compare the current sensing signal with the threshold level, adjust a digital control signal in response to the comparison, and provide the digital control signal to the DAC. The DAC may be configured to generate the control signal based on the digital signal. Accordingly, the digital control signal may be adjusted to shift the current sensing signal toward or below the threshold level or to maintain the current sensing signal below the threshold level.

[0058] In another embodiment, including an analog circuit system for controlling the surge current, the current sensing signal may be a voltage input signal indicating the current between the battery and the load, and the threshold level may be a reference voltage. The control module may include an error amplifier configured to receive the current sensing signal and the reference voltage as inputs and output the control signal. Accordingly, the control signal in this example may depend on the difference between the voltage input signal and the reference voltage.

[0059] The inverting input of the error amplifier can be connected to the reference voltage, and the non-inverting input can be connected to the current sensing signal. In this context, being connected can be considered as an electrical connection between the corresponding terminals of the error amplifier, which can be formed between rails or conductors carrying the reference voltage or current sensing signal. The control signal generated by the output of the error amplifier can be connected to a gate drive circuit for controlling the MOSFET. For example, when the MOSFET is a high-side MOSFET, a gate drive circuit can be provided to increase the voltage of the control signal to a gate voltage higher than the battery voltage, such that the gate-source voltage of the MOSFET is high enough to switch the MOSFET.

[0060] In another embodiment, the control signal may be a PWM signal, and the control module may be configured to adjust the duty cycle of the PWM signal based on the comparison between the current sensing signal and the threshold level. Accordingly, the MOSFET may be configured to switch between an "on" state and an "off" state at a rate determined by the duty cycle of the PWM signal, such that the effective Ro of the MOSFET... DS Therefore, the output current of the battery depends on the duty cycle of the PWM signal.

[0061] In this example, the effective R of the MOSFET can be... DS R is defined as the average value of the MOSFET over time as determined by the MOSFET's "off" time and "on" time. DS .

[0062] The control module may include a signal generator for generating the PWM signal.

[0063] Alternatively, the control module may include a microcontroller for generating the PWM signal. The PWM signal may be based on a comparison between the current-sensing signal and the threshold value. Accordingly, the PWM signal may be based on the current-sensing signal.

[0064] In some examples, if the current sensing signal is higher than the threshold level, the control module can be configured to generate the PWM signal with a first duty cycle. Accordingly, when the PWM signal operates with the first duty cycle, the MOSFET can have a corresponding first effective R... DS For all values ​​of the current sensing signal above the threshold level, the duty cycle of the PWM signal can be fixed, such that a fixed amount of current regulation is applied to the surge current until it decreases to a steady state.

[0065] Alternatively, the control module can be configured to drive the PWM signal with a variable duty cycle, the variable duty cycle depending on the difference between the current sensing signal and the threshold level. Therefore, the control module can be configured to gradually adjust the duty cycle of the PWM signal based on the current sensing signal.

[0066] When the current sensing signal is higher than the threshold level, the switching frequency of the PWM signal (e.g., with the first duty cycle) can be configured to be higher than the rate parameter of the MOSFET, causing the MOSFET to operate in its linear region. Correspondingly, when a high current is detected between the battery and the load, the MOSFET operates in its linear region, thus exhibiting a constant effective RV in series with the battery. DS This limits the current. The rate parameter can be the switching rate of the MOSFET, defined by the transition time between its on and off states.

[0067] If the current sensing signal is below the threshold level (or decreases to below the threshold level), the control module can be configured to adjust the duty cycle of the PWM signal to 100%, causing the MOSFET to be in an "on" state. Accordingly, when the inrush current decreases to a steady state, the PWM control of the MOSFET can be terminated, and thus the control of the inrush current can be terminated.

[0068] When the MOSFET is in the "on" state, it can operate in its saturation region and therefore has a lower "on" R. DS .

[0069] The switching from the first duty cycle to the 100% duty cycle can be executed as a step change in the PWM control signal. Accordingly, in this example, the MOSFET can have a fixed effective R value depending on the first duty cycle. DS The first duty cycle is used to limit the surge current until the current is sufficiently reduced and the MOSFET remains "on" for an extended period.

[0070] In other examples discussed herein, the control module may be configured to gradually increase the duty cycle of the PWM control signal as the surge current decreases, causing the MOSFET to operate for longer periods in the "on state," thereby gradually reducing the effective Ro of the MOSFET. DS This continues until the current drops below the threshold and the duty cycle of the PWM control signal reaches 100%.

[0071] In a further example, if the current sensing signal is above the threshold level and below the second threshold level, the control module can be configured to vary the duty cycle of the PWM signal based on the difference between the current sensing signal and the threshold level. Accordingly, as the surge current decreases to below the second threshold but still above the threshold level, the duty cycle of the PWM signal can begin to gradually increase, thereby gradually reducing the effective Ro of the MOSFET. DS Until the current reaches a steady state (where the current sensing signal is below a threshold level).

[0072] In a further aspect, a battery management system is provided for controlling inrush current generated by an electrical connection from a startup battery to an electrical load, wherein the battery management system includes a MOSFET, wherein the MOSFET is electrically connected between the battery and the load, and the effective drain-source resistance (Ro) of the MOSFET is... DS ) Regulates the current between the battery and the load; gate drive circuit for responding to a control signal to the R of the MOSFET DS The current control module of the first aspect is configured to provide the control signal for controlling the drain-source resistance R of the MOSFET. DS .

[0073] The gate drive circuit may include a gate drive transistor connected between the gate of the MOSFET and electrical ground. The control signal may be provided to the gate of the gate drive transistor, such that the gate-source voltage and thus the Ro of the gate drive transistor... DS The intermediate control voltage supplied to the gate of the MOSFET can be adjusted by the control signal such that it depends on the control signal. The intermediate control voltage may be the gate-source voltage of the MOSFET. In other examples, the intermediate control voltage may be boosted by the gate driver to a gate-source voltage for controlling the MOSFET.

[0074] As mentioned above, the MOSFET can be a low-side MOSFET or a high-side MOSFET. When the MOSFET is a high-side MOSFET, the gate drive circuit can include a high-side driver for boosting the intermediate control voltage to a gate-source voltage for driving the high-side MOSFET.

[0075] When the MOSFET is in the "on" state, the gate-source voltage can be higher than the battery's supply voltage. Correspondingly, when the source voltage is close to the battery voltage, the gate-source voltage can be boosted to exceed the MOSFET's switching threshold because the MOSFET is located on the high side of the load (or battery).

[0076] For example, the high-side driver may include a charge pump for boosting the intermediate control voltage to the gate-source voltage.

[0077] The battery management system may further include a current sensing circuit for detecting the current between the battery and the load, generating the current sensing signal, and providing the current sensing signal to the current control module. The current sensing circuit may be electrically connected between the low side of the load (or source) and the negative terminal of the battery.

[0078] For example, the current sensing circuit may include a sensing resistor and a current sensing amplifier, the sensing resistor being connected in series with the load, and the current sensing amplifier being configured to amplify the voltage drop across the sensing resistor.

[0079] The battery (for connection to the load / source via BMS) may have an internal resistance of 10 mΩ or less, 5 mΩ or less, or 1 mΩ or less. This low internal resistance can cause the battery to draw exceptionally high inrush current when connected to the load. This could cause conventional protection circuitry to completely disconnect the battery from the load, or damage the battery and / or the load, as conventional protection circuitry may be too slow to react to high current. Accordingly, the feedback loop provided in the control module of this invention enables more suitable and faster current protection, which can correspondingly increase or decrease the amount of protection provided.

[0080] Threshold levels can depend on the battery or the load (or source). For example, threshold levels can depend on battery size and / or battery internal resistance.

[0081] The threshold level used for comparison with the current sensing signal can correspond to a current from 50 A to 300 A, more preferably from 100 A to 250 A, and even more preferably from 150 A to 200 A. The threshold level can correspond to a current of 50 A or greater, preferably 100 A or greater, even more preferably 150 A or greater, and even more preferably 200 A or greater. The threshold level can correspond to a current of about 50 A, preferably about 100 A, even more preferably about 150 A, and even more preferably about 200 A.

[0082] The threshold level can correspond to the surge current between the battery and the load, which is 100 A to 300 A higher than the expected steady-state current between the battery and the load, more preferably 250 A higher than the expected steady-state current. Therefore, the BMS of the present invention is particularly suitable for high-current applications such as EV (electric vehicle) charging.

[0083] The expected steady-state current between the battery and the load is typically the current between the battery and the load when the MOSFET is turned on and the current is constant. The steady-state current can refer to a period of time after the inrush current has subsided, and can be considered as the average current flow over 5 seconds or longer, preferably 10 seconds or longer, more preferably 30 seconds or longer, after the connection between the battery and the load is initiated. The expected current flow can be predicted based on previous connections, and can be provided by a lookup table or preset by the user.

[0084] As mentioned above, a load can be a current source used to provide power to the battery (i.e., charge the battery). In this example, the MOSFET can be a charging MOSFET that is part of the source, where the source can be a charging device. Alternatively, a load can be a device used to receive power from the battery to discharge the battery.

[0085] In a second aspect, a method is provided to control inrush current generated by an electrical connection from a startup battery to an electrical load, wherein a MOSFET is electrically connected between the battery and the load, and the effective drain-source resistance (Ro) of the MOSFET is... DS The method includes the steps of: receiving a current sensing signal indicating the current between the battery and the load; comparing the current sensing signal with a threshold level; and adjusting a control signal for the MOSFET in response to the comparison to adjust the R of the MOSFET. DS The control is configured such that the current sensing signal is shifted toward or below the threshold level or is maintained below the threshold level.

[0086] For example, the method described in this aspect can be executed by a microcontroller provided in the BMS to regulate the current. The microcontroller can be an existing microcontroller provided in the battery pack, adapted to perform the method described in this aspect for regulation.

[0087] As discussed above with respect to the first aspect, the electrical load may refer to a load or a source, wherein the load may be a positive load or a negative load, and thus may supply current to the battery or draw current from the battery.

[0088] The method may further include the step of connecting the battery to the load / source via the MOSFET.

[0089] The method may further include the following steps: repeating the receiving step, the comparison step, and the adjustment step until the current sensing signal is below the threshold level (and the output current has reached a steady state). Accordingly, the method may be repeated as part of a continuous feedback loop for regulating the surge current.

[0090] The adjustment step may include adjusting the control signal to effectively adjust the MOSFET when the electrical connection between the battery and the electrical load is activated. DS Set as the initial resistance.

[0091] The adjustment step may include: when the current sensing signal is higher than the threshold level, adjusting the control signal to adjust the R of the MOSFET. DS Set as the first effective resistance; and when the current sensing signal has decreased below the threshold level, adjust the control signal to set the R of the MOSFET. DS It is set as the second resistor, which is lower than the first resistor.

[0092] In the adjustment step, the control signal can be adjusted to: when the battery is first connected to the load, the effective R of the MOSFET is... DS Set as the first resistor, and when the current sensing signal has decreased below the threshold level, set the effective R of the MOSFET. DS The second resistor is set as a lower resistance than the first resistor. Accordingly, in this example, the effective resistance provided by the MOSFET can be reduced in a stepwise manner after the surge current decreases below a certain threshold. For example, as described above regarding driving the MOSFET with a PWM control signal, the duty cycle of the PWM signal can be adjusted between: a predetermined duty cycle between 0% and 100% for regulating the current between the battery and the load, and a 100% duty cycle in which the MOSFET is in an "on" state and is not used to regulate the current.

[0093] In other examples, the control signal can be adjusted to gradually adjust the effective R of the MOSFET in response to the current sensing signal. DS .

[0094] In a further aspect, a computer-readable medium including instructions that, when executed by a processor, cause the processor to perform the methods described herein.

[0095] In other words, the methods disclosed herein can be implemented by a computer or processor to control the surge current. Therefore, this invention covers computer-readable media and computer program products including logic and / or instructions that, when executed by a computer's processor, cause the computer to implement the methods disclosed herein.

[0096] In a further aspect of the invention, a battery is provided, the battery including a battery management system according to the second aspect.

[0097] The battery may include multiple electrochemical units. The battery management system may be connected to the electrochemical units.

[0098] The battery (e.g., an electrochemical unit) may have an internal resistance of 1 mΩ or less. Each electrochemical unit may have an internal resistance of 1 mΩ or less.

[0099] In a further aspect of the invention, the current control module of the first aspect or the battery management system of the second aspect is provided for controlling the surge current generated by the electrical connection from the start-up battery to the load (or source).

[0100] In some embodiments, the current control module of the first aspect or the battery management system of the second aspect is provided for controlling the surge current generated by starting the low-impedance battery to the load (or source).

[0101] In another aspect, the current control module of the first aspect or the battery management system of the second aspect is provided for improving surge current control. For batteries connected to a load or source (such as low-impedance batteries), surge current control can be improved.

[0102] The present invention includes combinations of the described aspects and preferred features, unless such combinations are obviously not permitted or explicitly stated to be avoided. Attached Figure Description

[0103] The embodiments and experiments illustrating the principles of the present invention will now be discussed with reference to the accompanying drawings, wherein:

[0104] Figure 1 A block diagram of a battery-powered system according to the prior art is shown;

[0105] Figure 2 A block diagram of a battery-powered system according to various aspects of the present invention is shown;

[0106] Figure 3 The drain-source resistance of the MOSFET is shown. DS ) and MOSFET gate voltage (V GS (The image is a graphic representation of a shape or shape.)

[0107] Figure 4 A simplified process for controlling surge current according to various aspects of the present invention is shown;

[0108] Figure 5 The surge current drawn from the battery is shown in relation to the R of the MOSFET. DS and V GS A graphic that appears over time.

[0109] Figures 6 to 10 An example battery management system for controlling surge current is shown according to various aspects of the present invention;

[0110] Figure 11 Another example battery management system for controlling surge current is shown according to various aspects of the present invention;

[0111] Figure 12 The process for controlling surge current using PWM is shown;

[0112] Figure 13 Example simulation results of surge current without using the system limitations of this invention are shown;

[0113] Figure 14 A simulation circuit for controlling surge current according to various aspects of the present invention is shown;

[0114] Figure 15 It shows Figure 14 Simulation results of the simulation circuit;

[0115] Figure 16 Further simulation results for surge current without using the system limitations of this invention are shown;

[0116] Figure 17 Another simulation circuit for controlling surge current according to various aspects of the present invention is shown; and

[0117] Figure 18 It shows Figure 17 Simulation results of the simulation circuit. Detailed Implementation

[0118] Various aspects and embodiments of the invention will now be discussed with reference to the accompanying drawings. Other aspects and embodiments will be apparent to those skilled in the art. All documents mentioned herein are incorporated by reference.

[0119] In this specification, the term "battery" can refer to any number of battery cells arranged in one or more groups or modules, and a battery can consist of one or more sub-cells connected to provide power as appropriate. The battery can further be a modular system, allowing sub-cells to be removed, replaced, and added as needed to maintain and increase the functionality of the battery.

[0120] The cells included in the battery preferably include a negative electrode active material comprising a metal oxide. The metal oxide comprising the negative electrode active material is preferably a niobium-based material (such as niobium oxide), or a niobium metal oxide, such as niobium nickel oxide, niobium tungsten oxide, niobium titanium oxide, niobium molybdenum oxide, niobium aluminum oxide, niobium gallium oxide, niobium germanium oxide, niobium copper oxide, or niobium zinc oxide, for example as described in WO 2019 / 234248, the contents of which are incorporated herein by reference in their entirety. Accordingly, the negative electrode active material may include Nb2O5, Nb2NiO6, Nb12WO33, Nb26W4O77, Nb14W3O44, Nb16W5O55, Nb18W8O69, Nb2WO8, Nb18W16O93, Nb22W20O115, Nb8W9O47, Nb54W82O381, Nb20W31O143, Nb4W 7O31, Nb2W15O50, Nb2WO8, Nb2TiO7, Nb10Ti2O29, Nb24TiO62, Nb2Mo3O14, Nb14Mo3O44, Nb12MoO44, Nb11AlO29, Nb11GaO29, Nb49GaO124, Nb18GeO47, Nb34Cu2O87, or Nb34Zn2O8.

[0121] This material exhibits favorable lithium-ion diffusion characteristics, and therefore demonstrates excellent performance even when using micron-sized particles of niobium-based materials. Accordingly, anodes made of niobium-based materials, including niobium oxides or niobium metal oxides, exhibit extremely high volumetric energy density and high capacity at high charge-discharge ratios.

[0122] Alternatively, the metal oxide that includes the negative electrode active material may include another metal oxide that exhibits similar electrochemical properties, such as lithium titanium oxide, titanium dioxide, silicon oxide, or vanadium oxide.

[0123] Metal oxides can be combined with other suitable active materials (such as carbon, graphite) as well as other metal oxides.

[0124] Alternatively, the cells included in the battery may include other negative electrode active materials that do not combine with metal oxides, such as carbon and graphite.

[0125] In addition to the negative electrode, the electrochemical unit includes a positive electrode, an electrolyte, and a membrane between the negative electrode and the positive electrode, such as a microporous polyethylene film.

[0126] Suitable materials for the positive electrode include lithium-containing or lithium-intercalating materials, such as lithium metal oxides, wherein the metal can be a transition metal, such as Co, Fe, Ni, V, or Mn, or a combination thereof. Some examples of positive electrode materials include lithium cobalt oxide (LiCoO2), lithium nickel manganese cobalt oxide (NMC, LiNiMnCoO2, e.g., LiNi0.6Co0.2Mn0.2O2), lithium vanadium fluorophosphate (LiVPO4F), lithium nickel cobalt aluminum oxide (NCA, LiNiCoAl2), lithium iron phosphate (LFP, LiFePO4), and manganese-based spinel (e.g., LiMn2O4). In one embodiment, the positive electrode is substantially free of binder. In alternative embodiments, the positive electrode is mixed with a binder or adhesive. Some examples of binders or adhesives include PVDF, PTFE, CMC, PAA, PMMA, PEO, SBR, and copolymers thereof. The positive electrode can be fixed to a current collector substrate, such as an aluminum plate.

[0127] The electrolyte contains lithium salts, such as lithium bis(trifluoromethane)sulfonylimide (LiTFSI), LiPF6, LiBF4, LiCIO4, lithium trifluoromethanesulfonate (LiTF), or lithium bis(oxalate)borate (LiBOB). The electrolyte can be a liquid electrolyte, such as a liquid at ambient temperature (e.g., 25ºC). The electrolyte can be a non-aqueous electrolyte. The electrolyte can include polar aprotic solvents, such as cyclic or linear carbonates like ethylene carbonate, dimethyl carbonate, or ethyl methyl carbonate.

[0128] Figure 1 A simplified block diagram of a battery-powered system according to the prior art, including a battery pack 11 connected to a battery-powered device 12, is shown. The battery pack 11 and the battery-powered device 12 may coexist in a single housing, thus appearing as a single device, or they may be separate devices connected via appropriate power transfer mechanisms and protocols. Accordingly, the battery-powered device 12 may be an industrial device or tool, such as an industrial robot, industrial drill, etc.; a household device, such as a vacuum cleaner, food processor, etc.; or a personal device, such as a mobile phone, toothbrush, etc.; or a larger device, such as a battery-powered vehicle or other mobile device.

[0129] The battery pack 11 includes a battery 13 connected to a battery management system (BMS) 14, which performs balancing of the cells constituting the battery 13 based on detected voltage, current and temperature data, and may further include a protection circuit containing a fuse that acts as a buffer to protect the battery 13 from possible spikes during fast charging and discharging.

[0130] The battery-powered device 12 includes a load 16, the nature of which depends on the specific implementation. For example, it could be a motor driving wheels for self-propulsion, or it could be a computer processor in a device such as a personal computer. The load 16 is connected to a capacitor 15. Such capacitors are typically used in electronic circuits to minimize voltage ripple caused by switching in the power connection, and accordingly, the capacitor 15 is connected to the battery 13 and the BMS 14 via this power connection between the battery pack 11 and the battery-powered device 12.

[0131] When battery pack 11 is first connected to battery-powered device 12, capacitor 15 is typically fully discharged. Upon connection, an initial high current, referred to as "inrush current," flows from battery 13 into capacitor 15. The magnitude and duration of the inrush current depend on the input capacitance and output impedance of the input source. Increased inrush current level and duration can adversely affect battery safety and cycle life. Furthermore, if the input stage components of device 12 are designed for lower inrush current, thermal or overcurrent stress may occur on said input stage components.

[0132] The battery 13, with its fast charging and fast discharging capabilities, has low internal resistance, resulting in a longer duration of high inrush current. Consequently, it may trigger short-circuit and overcurrent protection mechanisms in the BMS 14, causing the BMS 14 to stop current flow and thus preventing the battery 13 from supplying power to the load 16.

[0133] There are several conventional methods to limit inrush current, but they are not suitable for high-power and high-current circuits involving low-impedance battery technology.

[0134] As described above, some conventional systems use negative temperature coefficient (NTC) devices such as thermistors, which change their internal resistance with increasing ambient temperature, such that the resistance increases as the temperature rises. This is effective because the temperature of the NTC can increase when a high current flows through it. However, this solution is not suitable for high-power and high-current circuits due to the significant power loss and potential overheating of NTCs during operation.

[0135] Other conventional systems use separate pre-charge circuits or soft-start mechanisms to limit inrush current. However, these mechanisms require new control schemes, power resistors, and additional circuitry in the receiving battery-powered device 12.

[0136] Finally, BMS 14 can be modified to increase the appropriate threshold to accommodate increased surge current levels. However, this reduces the effectiveness of short-circuit protection, leading to increased transient thermal stress on the battery, reduced cycle life, and potential damage to the battery, potentially including catastrophic damage such as fire or explosion.

[0137] Figure 2 A simplified block diagram of the system according to the present invention is shown. Similar to... Figure 1 In the system described herein, battery pack 21 is connected to battery power supply 22, which includes a load 27 and a capacitor 26, the capacitor acting as a filter on the input power supply. Battery pack 21 includes a battery 23 connected to a BMS 24, which is in turn connected to an output MOSFET 25. For clarity, MOSFET 25 is shown herein as a separate device, but it can be integrated into BMS 24. It can also be one of the MOSFETs currently present in many BMSs.

[0138] BMS 24 includes a controller 28 that receives information about battery 23, such as its temperature, state of charge, and output current. It is connected to a gate driver 29 within BMS 24, which is further connected to a MOSFET 25 to control its R... DS This control is performed by applying a variable gate voltage (V) to MOSFET 25 via gate drive 29. GS ), such that when the applied V GS When R increases DS Decrease, and vice versa. See below for reference. Figure 6 Describe the controller in more detail.

[0139] Figure 3 The R values ​​during discharge at two different temperatures are shown. DS (On the Y-axis) and V GS The relationship (on the X-axis). Light-colored curve 31 shows the different V values ​​at 125ºC. GS R at the level DS The change and the dark curve 32 show the different V values ​​at 25ºC. GS R at the level DS The change. In both cases, when V GS When R rises above 4 V DS This is significantly reduced, allowing higher current to flow through the MOSFET. Accordingly, during the initial surge current period, V0 GS The battery-powered unit 22 can be kept low and protected from potential damage from high surge currents regardless of temperature, which is an improvement over conventional NTC-based systems as described above.

[0140] Figure 4 An example process followed by controller 28 is shown.

[0141] In step S41, the battery pack 21 is connected to the battery power supply device 22 to supply power to the load 27.

[0142] At step S42, two things happen almost simultaneously. At step S42A, power is transferred from battery pack 21 to battery power supply unit 22, and capacitor 26 begins charging. At step S42B, controller 28 in BMS 24 detects the level of the inrush current and signals gate drive 29, which lowers the voltage applied to MOSFET 25. GS This causes the R of MOSFET25 to... DS Increase, such as Figure 3 As shown in the figure.

[0143] At step S43, controller 28 determines whether the surge current is higher than the desired threshold. If so, the process begins to branch right at "Yes" and returns to step S42B, where gate drive 29 maintains a low V. GS And correspondingly, the high R of MOSFET 25 DS .

[0144] If the surge current is below the desired threshold, the process begins at "No" and proceeds left along the branch to step S45. This corresponds to the following description. Figure 5 At the second time point 53, in step S45, the controller 28 sends a signal to the gate drive 29, which raises the V applied to the MOSFET 25. GS ,like Figure 5 Point 55 is shown.

[0145] As a result, at step S46, the R of MOSFET 25... DS The current is reduced. The process ends here, but it can continue to be applied at any point during the connection between the battery and the load (e.g., during a power surge) to regulate the current.

[0146] Since the initial surge current has already passed, V GS And correspondingly R DS It can remain stable and, depending on the nature of battery 23, may continue to supply power at a higher rate than is common in conventional systems with minimal power dissipation. Unlike conventional methods for addressing inrush current issues, there is no need to reduce short-circuit protection or add additional components, especially resistors that cause overheating and power dissipation during normal use.

[0147] In showing R DS Surge current, and V GS Correspondence Figure 5 The process is further illustrated in R. DS Represented by curve 56 with dashed lines, V GSThe surge current is represented by curve 58, which is a dotted line, and by line 57, which is a line with alternating dots and dashes. Although these three curves use different units on the Y-axis, they are shown on the same graph to illustrate their behavior at different points in time. Corresponding time points and time periods are indicated by arrows and brackets.

[0148] For example, the first arrow 51 indicates the point where the connection between the battery and the load device is formed, corresponding to Figure 4 Step S41. The first bracket 52 indicates the time during which the peak surge current charges the capacitor 26. During this time, as previously referenced... Figure 4 As described in step 42, V GS It is kept low, thus resulting in a high R of the MOSFET. DS At time point 53, the surge current decreases to the desired threshold. The second bracket 54 indicates the transition region during which the peak surge current has decreased to a steady state. During this time period, as previously referenced... Figure 4 As described in step 45, V GS Increase thus leading to R of the MOSFET DS Decrease. The third bracket 55 indicates the steady-state region, where V GS And correspondingly R DS It is kept in a stable "on" state to transfer power between the battery and the load device during typical operation.

[0149] Figure 6 An example battery management system (BMS) 100 is shown for connecting a battery 120 to a load 122 to regulate the inrush current between the battery 120 and the load 122. The load 122 has an associated input capacitance C1, and the BMS includes a controller 128 (which may also be referred to as a control module), a gate driver 112, a high-side MOSFET 110, and current sensing circuitry 130, 132, 136. The battery 120 is electrically connected to one side (i.e., the drain) of the MOSFET 110, and the load 122 is electrically connected to the other side (i.e., the source) of the MOSFET 110. The gate driver 112 is configured to operate the gate of the MOSFET 110 according to a control signal provided by the controller 128.

[0150] The controller 128 is configured to receive current sensing signals from the current sensing circuitry 130, 132, 136 and adjust the control signal to the gate driver 122 based on a comparison between the current sensing signals and a threshold level.

[0151] Gate driver 112 is configured to apply a variable gate voltage (V) to MOSFET 110 based on a control signal from controller 128.GS For example, gate driver 112 may include a charge pump for boosting a control signal to a gate voltage (V) higher than the battery voltage. GS This is used to drive the high-side MOSFET 110. The control signal is configured to operate the MOSFET 110 in its linear region, such that when V... GS When increased, the R of MOSFET 110 DS It decreases, and vice versa.

[0152] exist Figure 6 In this circuit, current sensing circuitry 130, 132, and 136 includes a sensing resistor 136, a current sensing amplifier 130, and an ADC 132. The sensing resistor is connected in series with a load 122 and a battery 120. Current therefore flows between the load 122 and the battery 120 through the sensing resistor 136 (which has a low resistance, e.g., 1 mΩ). The potential difference generated across the sensing resistor 136 is amplified by the sensing amplifier 130 to provide a current sensing signal, in this case, a voltage input signal to the ADC 132. The ADC 132 converts the input voltage into a digital signal for processing by the controller 128 to generate a MOSFET control signal. In some examples, the ADC 132 may be included in the controller 128 (e.g., within a microcontroller package) or may not be included at all (e.g., when using analog components to compare the voltage input with a threshold level, as referenced below). Figure 8 and Figure 9 (As discussed).

[0153] In this manner, controller 128 can sample the current sensing signal and adjust the MOSFET control signal to regulate the inrush current in the continuous feedback loop. Controller 128 can be configured to generate and adjust the MOSFET control signal in various ways, including using a processor, such as a microcontroller (e.g., as described below). Figures 7 to 8 (as discussed); or using analog circuit systems (e.g., as follows regarding...) Figures 9 to 10 (as discussed); or by adjusting the duty cycle of the PWM control signal (e.g., as follows regarding...). Figures 11 to 13 (As discussed).

[0154] Figure 7 and Figure 8 An embodiment of a system 200 for connecting a battery 220 to a capacitive load 222 is shown, wherein the controller includes a microcontroller (MCU) 228. In these examples, the MCU 228 is configured to provide digital control signals to a DAC 225, which generates analog control signals for controlling a MOSFET 210 via a gate driver.

[0155] exist Figure 7 and Figure 8 In this configuration, the gate driver includes a drive transistor 234 connected between the gate of the high-side MOSFET 210 and electrical ground. The gate of the drive transistor 234 is controlled by an analog control signal. Accordingly, when the control signal adjusts the gate voltage of the drive transistor 234, the resistance of the drive transistor 234 is adjusted, and thus the voltage of the high-side MOSFET 210 is modified. GS .

[0156] exist Figure 7 In the middle, the gate driver includes a power supply 211 for converting V GS The voltage is boosted to a level higher than the battery voltage to operate the high-side MOSFET 210. Additionally, Figure 7 The current sensing circuit system includes a sensing resistor 236 and a sensing amplifier 230 as described above. The generated sensing voltage is provided to the MCU 228 for adjusting the control signal in the continuous feedback loop.

[0157] exist Figure 8 In this configuration, the gate driver includes a charge pump for supplying V0 to the MOSFET 210. GS The voltage is boosted. In this example, the charge pump is part of an existing BMS 212 that already includes a battery 220 and is adapted for regulating current using the techniques discussed herein. Additionally, in this example, the current sensing circuitry for measuring the voltage drop across the sensing resistor 236 is also part of the existing BMS 212.

[0158] Figure 9 A battery management system 300 is shown, in which analog components are used to generate control signals for controlling MOSFET 310. The BMS 300 is configured to connect battery pack 320 (via terminals B+ and B-) to load 322 (via terminals P+ and P-). (See above for...) Figure 6 As described, a current sensing circuit system is provided, which includes a sensing resistor 323 and a sensing amplifier 330 for generating a current sensing signal indicating the current flowing between the battery 320 and the load 322.

[0159] The current sensing signal is provided to the non-inverting input of the error amplifier 332 (i.e., the operational amplifier (op-amp)). The voltage reference signal (V...) 基准 The threshold level is provided to the inverting input of error amplifier 332 as a comparison point with the current sensing signal. For example, V can be generated using any suitable method for providing a voltage reference, such as a voltage reference IC, Zener diode, resistor divider, voltage regulator, etc. 基准 .

[0160] The output of error amplifier 332 is provided as a control signal to drive the gate of high-side MOSFET 310.

[0161] As mentioned above Figure 7 and Figure 8 As described, a control signal is used to operate a drive transistor 334, which is then configured to control the gate of the high-side MOSFET 310. Similarly, a charge pump 312 is provided to make the Vo of the high-side MOSFET 310... GS Boost pressure.

[0162] As a general rule, the op-amp in a closed loop (such as...) Figure 9 The error amplifier 332 will adjust its output to reduce the voltage difference between its inputs to zero. Accordingly, Figure 9 Error amplifier 332 will be used to process the current sensing signal (i.e., V) through the following steps. 感测 Equalized to the threshold level (i.e., V) 基准 ): Adjust its output (control signal) and therefore the R of the high-side MOSFET310 DS This is to regulate the surge current until the current sensing signal equals the threshold level. Accordingly, as the surge current decreases to a steady state over time, the error amplifier 332 will adjust the control signal accordingly to adjust the Rs of the high-side MOSFET 310. DS Reduce until MOSFET 310 operates in a fully "on" state.

[0163] Figure 10 Another embodiment of a battery management system 300, including analog components for controlling the high-side MOSFET 310, is shown. This embodiment is very similar to... Figure 9 In this embodiment, the same components have the same reference numerals. However, in this embodiment, the battery management system 300 is used to connect the battery 320 to the battery charger 360. Accordingly, the battery charger 360 is a current source, and the surge current observed when the charger 360 is first connected to the battery 320 is related to... Figure 9 The system flows in the opposite direction. In this example, the source of MOSFET 310 can be connected to battery 320, which is the low side of MOSFET 310 in this example, and the drain of MOSFET 310 can be connected to battery charger 360. Accordingly, in this example, MOSFET 310 can be considered as a charging MOSFET 310 (rather than as...). Figure 9 (Discharge MOSFET in the middle).

[0164] Figure 11Another battery management system 400 is shown, in which a method called pulse charging is used to mitigate inrush current, which involves using a pulse width modulation (PWM) gate driver 432. Figure 9 and Figure 10 The same components in the implementation scheme have the same reference numerals. Broadly speaking, PWM control signals can be used to reduce inrush current by increasing the voltage rise time on the load capacitor and slowing down the charging rate of the load capacitor. This can be achieved by controlling the duty cycle and / or frequency of the PWM signal, thereby effectively controlling the average power delivered to the load capacitor.

[0165] exist Figure 11 In the BMS 500, there are a current sensing amplifier 430, a sensing resistor 436, a gate drive transistor 434, a charge pump 412, and a high-side MOSFET 410, each of which is described above for... Figures 6 to 10 The implementation scheme operates as described. However, in this implementation, the BMS 400 includes a PWM driver 432 for providing a PWM control signal to the gate drive transistor 534. The PWM driver 432 is configured to generate a PWM control signal for a period of time upon detecting an inrush current, until the load capacitor is charged and the inrush current has decreased to a steady state.

[0166] The current sensing circuitry detects the surge current level as a voltage drop across a low-value sensing resistor 436, and the current sensing amplifier 430 amplifies the voltage across the sensing resistor 436 for detection by the PWM driver 432. The PWM driver 432 can be a microcontroller (MCU) or a controllable PWM signal generator. Upon detecting a surge current, the PWM driver 432 is configured to generate a high-frequency PWM control signal with a fixed switching frequency (and a fixed or variable duty cycle) until the surge current decreases to a certain point (i.e., when the current sensing signal has decreased below a threshold level) and the load capacitor is charged to a safe voltage level.

[0167] For example, the switching frequency of the PWM signal can be between 100 kHz and 500 kHz. (This is from an article about...) Figure 17 and Figure 18 In the simulation example discussed, the switching frequency of the PWM control signal was set to 250 kHz. However, the specific switching frequency can vary depending on the specific MOSFET model and inrush current level.

[0168] In some cases, a fixed duty cycle can be used for the PWM control signal. However, in other cases, a variable duty cycle can be used. For example, the duty cycle of the PWM control signal can be increased over time, causing the MOSFET to remain "on" for a longer period as the inrush current decreases, thereby reducing the effective (average) RV of the MOSFET. DS .

[0169] After the inrush current has decreased to below a threshold level (which may be, for example, a predetermined value stored in the PWM driver 432), the control signal provided to the gate drive transistor 534 switches from a PWM control signal to a full-active mode signal (i.e., a control signal without pulse width modulation with a 100% duty cycle), causing the high-side MOSFET 410 to remain in the "on" state and the load 422 to be continuously powered. The switching frequency and duty cycle of the PWM control signal can be configured based on parameters of the high-side MOSFET 410 (e.g., on-off transition time or slew rate), such that during the current surge, the high-side MOSFET 410 operates at a relatively high Ro. DS It operates in its linear region. In particular, the switching frequency of the PWM control signal can be configured to be faster than the switching rate of the MOSFET 410.

[0170] Figure 12 It shows how to use Figure 11 The system controls the surge current process. For example, a control module including a PWM driver 532 can follow this process.

[0171] First, in step S501, the battery pack 420 is connected to the load 422 via the BMS 400.

[0172] At step S402, two things happen almost simultaneously. First, at step S402A, power is transferred from battery pack 420 to load 422, and charging of the load capacitor begins. Second, at step S502B, PWM driver 432 detects a high current surge (i.e., inrush current) and provides a PWM control signal with a fixed frequency and duty cycle to gate drive transistor 434. This causes high-side MOSFET 410 to turn on and off at a rate determined by the PWM, which in turn causes the load capacitor to charge more slowly (i.e., pulse charging), and causes R of high-side MOSFET 410 to... DS Effective increase.

[0173] At step S503, the voltage across the load capacitor begins to increase as the capacitor charges, thus reducing the surge current.

[0174] At step S504, the PWM driver 432 determines whether the surge current is higher than the desired threshold. If so, the process begins to branch right at "Yes" and returns to step S502B, where the gate driver 432 maintains pulse width modulation of the control signal and the effective high R of the MOSFET. DS .

[0175] However, if the current is lower than the desired threshold in step S504, the process starts to move left along the branch to steps S505 and S506 at "No", where the PWM driver terminates the pulse width modulation of the control signal.

[0176] At step S506, a control signal is configured to operate the high-side MOSFET 410, which is in an "on" state. The process ends here, but it can continue to be applied at any point during the connection between the battery 420 and the load 422 (e.g., during a power surge) to regulate the current.

[0177] Accordingly, in Figure 12 In this example, the PWM driver 428 is configured to switch between a fixed PWM control signal and a constant on-state control signal depending on whether the inrush current has decreased below a threshold level. Therefore, in this case, a fixed level of regulation is applied to the inrush current.

[0178] However, in other examples, the PWM driver 428 can be configured to adjust the duty cycle of the PWM control signal based on the difference between the current sensing signal and a threshold level. For example, as the inrush current decreases, the duty cycle of the PWM control signal can be increased, causing the MOSFET 410 to remain on for a longer period of time until the current has reached a steady state.

[0179] simulation

[0180] Figure 13 An example simulation result is shown for the inrush current generated by the electrical connection from the startup battery to the load. In this simulation, the system of the present invention is not used to limit the inrush current. (a) shows the flow through the sensing resistor (i.e., Figure 13 (a) shows the surge current versus time for R2), (b) shows the Vds (drain-source voltage) of the MOSFET, (c) shows the output voltage (i.e., charging the capacitive load), and (d) shows the power drawn from the battery (i.e., P = I*V). In this simulation, the capacitive load was connected to the battery at 10 ms. Accordingly, a high current surge (0.6 KA) and a high power surge (1.5 kW) were observed at 10 ms when initializing the connection between the battery and the load. This could be damaging to the load and / or the battery.

[0181] Figure 14 The above shows the method for using... Figure 9 The described analog circuit system is a simulation circuit for controlling surge current.

[0182] Figure 15 It shows Figure 14 The simulation results of the simulation circuit are shown in Figures (a) to (d) as above for the simulation circuit. Figure 13 The surge current, Vds, output voltage, and power drawn from the battery are discussed. For example... Figure 15 As shown, the current and power drawn from the battery are now greater than... Figure 13 The values ​​in the middle are much lower and much smoother. For example, in Figure 15 In the figure, the current (see (a)) peaks at exactly 250 A, and the power (see graph (d)) peaks at exactly 4 KW.

[0183] Figure 16 It was shown (using) Figure 17 Further simulation results of the surge current generated by the simulation circuit are provided, without using the system current limit of this invention (i.e., when MOSFET M1 remains "on"). Figures (a) to (d) show the surge current as described above for... Figure 13 The surge current, Vds, output voltage, and power drawn from the battery are discussed, with the capacitive load and battery connected at 10 ms in the simulation. As shown in (c), the battery pack output voltage is 20V when the battery is connected to the load. As shown in (a), in this example, the current surge between the battery and the load is approximately 1000 A when the battery is connected to the load, and as shown in (d), the peak power drawn from the battery is approximately 2 kW.

[0184] Figure 17 The above reference shows how to use it. Figure 11 and Figure 12 The simulation circuit describes a PWM control signal used to control inrush current. In this simulation, the switching frequency of the PWM control signal is 250 kHz. The duty cycle of the PWM signal is initialized to 1% and increases to 100% over time, during which the PWM signal does not switch at all.

[0185] Figure 18 Showing from Figure 17 The simulation results of the simulation circuit. For example... Figure 18As shown, the current drawn from the battery (a), drain-source voltage (b), output voltage (c), and power (d) all pulsate synchronously with the pulse width modulation signal. Accordingly, the average values ​​of the current and power drawn from the battery are significantly reduced. After approximately 430µs, the current has decreased below the threshold level, and the PWM-switched MOSFET is no longer used.

[0186] Other preferences

[0187] This document explicitly discloses each and every compatible combination of the implementation schemes described above, as if each and every combination were listed individually and explicitly.

[0188] In view of this disclosure, various further aspects and embodiments of the invention will be apparent to those skilled in the art.

[0189] As used herein, “and / or” should be considered as a specific disclosure of each of the two specified features or components having or not having the other. For example, “A and / or B” should be considered as a specific disclosure of each of (i) A, (ii) B, and (iii) A and B, as if each were described separately herein.

[0190] Unless the context otherwise requires, the description and definition of the features set forth above are not limited to any particular aspect or embodiment of the invention, and equally apply to all aspects and embodiments described.

[0191] Certain aspects and embodiments of the invention will now be illustrated by way of example and with reference to the accompanying drawings described above.

[0192] References

[0193] All references cited in this specification are incorporated herein by reference in their entirety.

[0194] US6067239

[0195] EP3080540

[0196] US 2019 / 0229527

[0197] US 2009 / 0189588

[0198] WO 2024 / 019666.

Claims

1. A current control module for controlling the surge current generated by the electrical connection from a starting battery to an electrical load. The metal-oxide-semiconductor field-effect transistor (MOSFET) is electrically connected between the battery and the electrical load, and the effective drain-source resistance (Ro) of the MOSFET is... DS Adjust the current between the battery and the electrical load; and The control module is configured as follows: Receive a current sensing signal, the current sensing signal indicating the current between the battery and the electrical load. The current sensing signal is compared with a threshold level, and In response to the comparison, the control signal for the MOSFET is adjusted to adjust the R of the MOSFET. DS The control is configured such that the current sensing signal is shifted toward or below the threshold level or is maintained below the threshold level.

2. The current control module of claim 1, wherein the control signal is adjusted proportionally to the difference between the current sensing signal and the threshold level.

3. The current control module of claim 1 or 2, wherein the control module is configured to, upon activating the electrical connection from the battery to the electrical load, adjust the Ro of the MOSFET. DS Set as the initial effective resistance.

4. The current control module as described in any one of claims 1 to 3, wherein the control module is configured to: When the current sensing signal is higher than the threshold level, the R of the MOSFET will be... DS Set as the first effective resistance, and When the current sensing signal has decreased to below the threshold level, the R of the MOSFET will be... DS The resistance is reduced to a second effective resistance, which is lower than the first effective resistance.

5. The current control module of any of the preceding claims, wherein the control signal is configured to cause the MOSFET to operate in its linear region when the current sensing signal is above the threshold level.

6. The current control module as described in claim 5, wherein the control signal is an analog signal adjustable between a minimum voltage and a maximum voltage. The minimum voltage corresponds to the maximum R of the MOSFET. DS And the maximum voltage corresponds to the minimum R of the MOSFET. DS .

7. The current control module of claim 6, wherein the control signal depends on the difference between the current sensing signal and the threshold level.

8. The current control module as claimed in any of the preceding claims, wherein the current control module includes a microcontroller and a digital-to-analog converter (DAC). The microcontroller is configured to receive the current sensing signal, compare the current sensing signal with a threshold level, adjust a digital control signal in response to the comparison, and provide the digital control signal to the DAC; and The DAC is configured to generate the control signal based on the digital signal.

9. The current control module of any preceding claim, wherein the current sensing signal is a voltage input signal, the voltage input signal indicating the current between the battery and the electrical load. The threshold level is a reference voltage, and The control module includes an error amplifier configured to receive the current sensing signal and the reference voltage as inputs, and to output the control signal.

10. The current control module of claim 8, wherein the inverting input of the error amplifier receives the reference voltage, and the non-inverting input of the error amplifier receives the current sensing signal. The control signal output from the error amplifier is connected to the gate drive circuit to control the MOSFET.

11. The current control module of any one of claims 1 to 5, wherein the control signal is a PWM signal, and the control module is configured to adjust the duty cycle of the PWM signal based on the comparison between the current sensing signal and the threshold level.

12. The current control module of claim 11, wherein the control module includes a signal generator for generating the PWM signal.

13. The current control module of claim 11, wherein the control module includes a microcontroller for generating the PWM signal.

14. The current control module as described in any one of claims 11 to 13, wherein, If the current sensing signal is higher than the threshold level, the control module is configured to generate the PWM signal with a first duty cycle.

15. The current control module of claim 14, wherein the switching frequency of the PWM signal at the first duty cycle is higher than the rate parameter of the MOSFET, causing the MOSFET to operate in its linear region.

16. The current control module as described in any one of claims 10 to 15, wherein, If the current sensing signal is lower than the threshold level, the control module is configured to adjust the duty cycle of the PWM signal to 100%, so that the MOSFET is in the "on" state.

17. A battery management system for controlling inrush current generated by an electrical connection from a starting battery to an electrical load, wherein the battery management system comprises: A MOSFET, wherein the MOSFET is electrically connected between the battery and the load, and the effective drain-source resistance (Ro) of the MOSFET is... DS It is configured to regulate the current between the battery and the load. Gate drive circuit for controlling the R of the MOSFET in response to a control signal. DS ,as well as The current control module according to any one of claims 1 to 15 is used to provide the control signal.

18. The battery management system as described in claim 17, The gate drive circuit includes a gate drive transistor connected between the gate of the MOSFET and electrical ground. The control signal is provided to the gate of the gate driving transistor, such that the gate-source voltage of the gate driving transistor and thus R DS It can be adjusted by the control signal. This results in the intermediate control voltage supplied to the gate of the MOSFET being dependent on the control signal.

19. The battery management system of claim 18, wherein the MOSFET is a high-side MOSFET electrically connected to the high side of the load, and the gate drive circuit includes a high-side driver for boosting the intermediate control voltage to a gate-source voltage for driving the high-side MOSFET, and Optionally, the high-side driver includes a charge pump for boosting the intermediate control voltage.

20. The battery management system of any one of claims 17 to 19, further comprising a current sensing circuit for detecting the current between the battery and the load, generating the current sensing signal, and providing the current sensing signal to the current control module, and Optionally, the current sensing circuit includes a sensing resistor and a current sensing amplifier, the sensing resistor being connected in series with the load, and the current sensing amplifier being configured to amplify the voltage drop across the sensing resistor.

21. The battery management system of any one of claims 17 to 20, wherein the battery management system is used for a battery having an internal resistance of 1 mΩ or less.

22. The battery management system of any one of claims 17 to 21, wherein the threshold level corresponds to a surge current of 250 A or greater between the battery and the load.

23. A method for controlling inrush current generated by an electrical connection from a starting battery to an electrical load. The MOSFET is electrically connected between the battery and the electrical load, and the effective drain-source resistance (Ro) of the MOSFET is... DS Adjust the current between the battery and the electrical load; The method includes the following steps: Receive a current sensing signal, the current sensing signal indicating the current between the battery and the electrical load. The current sensing signal is compared with a threshold level, and In response to the comparison, the control signal for the MOSFET is adjusted to adjust the R of the MOSFET. DS The control is configured such that the current sensing signal is shifted toward or below the threshold level or is maintained below the threshold level.

24. The method of claim 23, further comprising the following steps: The battery is connected to the electrical load via the MOSFET, and When the electrical connection between the battery and the electrical load is activated, the control signal is adjusted to enable the MOSFET to operate at its maximum Ro. DS Set as the initial resistance.

25. The method of claim 23 or claim 24, further comprising the following steps: When the current sensing signal is higher than the threshold level, the control signal is adjusted to adjust the R of the MOSFET. DS Set as the first effective resistance, and When the current sensing signal has decreased to below the threshold level, the control signal is adjusted to adjust the R of the MOSFET. DS It is set as the second resistor, which is lower than the first resistor.

26. A computer-readable medium comprising code, which, when executed by a processor, causes the processor to perform the method as claimed in any one of claims 23 to 25.

27. Use of the current control module as claimed in claims 1 to 16 or the battery management system as claimed in claims 17 to 22 for improving surge current control.

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