Monitoring unit for security of a cell

Abstract

The invention relates to a monitoring unit (100) for ensuring cell safety during a stationary mode of a battery management system (112) for a battery, the monitoring unit has a cell line (102), a current detection module (104), a cell monitoring module (106) having a wake-up mode and a sleep mode, a hardware-current monitoring module (108), a current interruption module (110), a battery management system (112) and at least one first time measurement module (114.1) and at least one second time measurement module (114.2), wherein the at least one first time measurement module (114.1) and the at least one second time measurement module (114.2) are designed to detect a maximum duration of at least one limit violation of the measured values of the cell line (102).

Description

Technical Field

[0001] This invention relates to a monitoring unit for ensuring single-cell safety during the quiescent mode of a battery management system for a battery. Furthermore, this invention relates to a method for ensuring single-cell safety during the quiescent mode of a battery management system for a battery. Background Technology

[0002] Most vehicle manufacturers using lithium-ion batteries, whether in high-voltage, 48-volt, or low-voltage applications, have established safety objectives and developed products according to the ISO 26262 standard to demonstrate compliance with these objectives. These objectives particularly include fire prevention, which can result from the thermal decomposition of lithium single cells.

[0003] Therefore, to achieve the aforementioned safety objectives, manufacturers utilize extensive monitoring systems that monitor the status of individual battery cells according to the requirements of the individual cell monitoring module. This includes continuous monitoring of individual cell voltage, temperature, and current. To enable early response to potential hazards, these parameters are continuously compared to defined safety-related thresholds.

[0004] To minimize current consumption, it is essential to keep the vehicle running continuously with minimal energy consumption when not in use. Here, lithium-ion batteries are crucial components for ensuring the current supply to all vehicle components. Continuous monitoring of situations that may exceed the safety thresholds of the stored batteries, as well as precise measurement of current consumption, are indispensable, but these are technically impossible to achieve with current technology.

[0005] US 2017 210 229 A1 relates to a method for operating a battery system comprising multiple individual battery cells and a battery management system for monitoring and controlling the individual battery cells. The battery management system includes a main regulator, a first measurement chain, and a second measurement chain. Each measurement chain includes multiple measurement chips that redundantly acquire measurement data from the individual battery cells and perform diagnostics and state-of-charge compensation for the individual battery cells. In this embodiment, the battery system has a control channel by means of which the hierarchical states of the two measurement chains are defined. In the event of a failure in one measurement chain, the battery system is switched to a mode with reduced availability, and the hierarchical states are adjusted such that the other measurement chain assumes the responsibility for acquiring measurement data, diagnostics, and state-of-charge compensation. Furthermore, a computer program and a battery management system designed to implement the method are described. Additionally, an application of the method is described in a battery system and a motor vehicle whose drive system is connected to the battery. Summary of the Invention

[0006] According to the present invention, a monitoring unit is proposed for ensuring single-cell safety during the quiescent mode of a battery management system for a battery. The monitoring unit includes a single-cell circuit, a current detection module, a battery monitoring module with wake-up and sleep modes, a hardware-based current monitoring module, a current interruption module, a battery management system, and at least one first-time measurement module and at least one second-time measurement module. The at least one first-time measurement module and the at least one second-time measurement module are configured to detect a maximum duration for violations of at least one limit value of the single-cell circuit's measured values.

[0007] The monitoring unit according to the invention, used to ensure the safety of a single battery cell during the static mode of a battery management system for a battery, advantageously provides a monitoring unit that guarantees the minimum possible energy utilization of the battery during, for example, the stationary state of a vehicle. The monitoring unit also advantageously guarantees that energy is always supplied by the battery to all loads of, for example, the vehicle's onboard electrical network. Furthermore, the monitoring unit ensures the effective identification of single-cell limit violations and the duration of such violations. The monitoring unit also ensures the minimization of risks that could lead to functional disturbances, damage to a single battery cell or the battery as a whole, or safety-related accidents.

[0008] The monitoring unit, a central component of the system, ensures the safety of individual cells within the energy storage system. This unit continuously or periodically monitors a range of key parameters of each cell, including voltage, current, and temperature. This ensures compliance with all relevant limits. Upon identifying deviations or potentially hazardous conditions, such as overvoltage (e.g., overcharging), undervoltage (e.g., over-discharging), overheating, or short circuits, the monitoring unit activates appropriate protective measures. These measures are implemented based on the collected values ​​and identified conditions. These measures include, in particular, disconnecting the battery, prohibiting further use (activation) of the cell, and triggering alarms from other safety systems.

[0009] The quiescent mode of a Battery Management System (BMS) represents a battery state characterized by a reduced range of functions within the system used to monitor and regulate the battery state. This ensures minimal energy consumption of the system itself. In quiescent mode, the battery's voltage state is continuously or periodically monitored while energy-intensive functions are disabled. Quiescent mode is terminated by an external trigger, which may be triggered by, for example, connection to a charging device, increased discharge current, significant voltage changes, or violation of safety limits (such as insufficient voltage). Vehicle-specific triggers can also terminate quiescent mode. The current detection module of the monitoring unit is a component or circuit that detects the current flowing in the circuit, preferably in a single-cell circuit.

[0010] The single-cell monitoring system represents an integrated system within the scope of the proposed monitoring system, which monitors the status of each individual cell. Furthermore, the single-cell monitoring system includes multiple sensors, such as those ensuring the measurement of voltage and temperature for each cell or battery. Additionally, a control and balancing mechanism is preferably integrated to ensure that all cells remain within their permissible limits. Moreover, the single-cell monitoring system in the proposed system can output appropriate reports upon the occurrence of faults or abnormal characteristics, thereby ensuring early identification and elimination of problems. Precise monitoring and periodic adjustment of single-cell voltage by the system leads to optimization of the power, safety, and lifespan of the single-cell circuitry. Ideally, the single-cell monitoring module has an active mode, also known as a wake-up mode, and a sleep mode.

[0011] A single-cell circuit is a battery assembly configured to achieve desired electrical characteristics, such as voltage and capacitance. A circuit referred to as a "single-cell circuit" can be implemented as an assembly of multiple conductive single cells. A battery or accumulator is mentioned here as an example. Such a single-cell circuit allows for optimization of power consumption depending on existing requirements. Here, not only are series connections of the assembly possible, but parallel connections are also possible.

[0012] The Hardware Current Supervision (HW) module is a component of a monitoring module that ensures the monitoring and recording of current in switching circuits, particularly in single-cell battery circuits. The HW module's functionality is based on the guarantee that current flow is allowed within defined limits. This prevents potential damage to the device and impairs its function.

[0013] Hardware-based current monitoring modules, such as those for monitoring current flow, are used to measure current flow, either continuously or at time intervals. Furthermore, these modules ensure that current consumption remains within limits. An alarm is triggered when limits are exceeded to identify potential overloads or faults before serious damage occurs. Additionally, the modules protect the equipment under unusual or hazardous current conditions, such as sudden overloads or short circuits. This includes automatic disconnection and / or interruption of current flow to prevent damage to individual circuits. Moreover, a design for the hardware-based current monitoring module can be envisioned where collected measurements are stored over a longer period. These measurements are then evaluated to analyze current consumption, identify programs or anomalies, and / or optimize energy efficiency.

[0014] A current interruption module, also known as a "Current Interruption Device" in English, represents an electronic component or circuit that interrupts or monitors current flow in a single-cell circuit. Current interruption modules are used, for example, in battery management systems (BMS), energy storage systems, charging equipment, or protection circuits. In particular, a current interruption module ensures the interruption of current flow into or out of a single cell within safe operating ranges, but also ensures protection against overcurrent, short circuit, or overload of electrical components, while simultaneously providing a feasible solution for targeted control of current flow, for example, without the use of mechanical switches or relays. For the monitoring system according to the invention, the current interruption module is preferably used in embodiments as a back-to-back MOSFET structure. In a back-to-back MOSFET structure, the current interruption module comprises two MOSFETs (Metal-Oxide-Semiconductor Field-Effect Transistors) connected in opposite directions, which control not only current flow in one direction but also current flow in the opposite direction. The back-to-back MOSFET structure has proven particularly advantageous in applications where bidirectional current occurs, such as during the charging and discharging of a battery in a single-cell circuit. This allows current to flow in both directions. Furthermore, the back-to-back MOSFET structure is characterized by efficient switching time, as the MOSFETs respond to control signals with almost no delay.

[0015] As a single-pool monitoring module, an integrated circuit (ASIC) can be used, for example. In contrast, a hardware-based current monitoring module can be constructed, for example, as a current measurement amplifier combined with a threshold comparator and additional shunt resistors or Hall elements.

[0016] A battery management system (BMS) represents an electronic system comprising software and hardware that enables monitoring and control of power and safety within a single-cell circuit. The BMS is a crucial component, particularly in applications using lithium-ion batteries such as electric vehicles, energy storage systems, or portable devices. The BMS of the monitoring module proposed in this invention ensures efficient operation of the single-cell circuit and provides extensive protection against potential damage.

[0017] In an advantageous design of the monitoring unit according to the present invention, at least one first time measurement module and / or at least one second time measurement module are implemented as application-specific integrated circuits or as discrete analog components and are fully or partially integrated into a single-cell monitoring module or a hardware-current monitoring module.

[0018] In one advantageous design of the monitoring unit according to the present invention, the monitoring unit includes discrete analog components, at least one capacitor or at least one resistor or at least one integrated timer assembly.

[0019] In another advantageous design of the monitoring unit according to the present invention, the battery management system is configured to activate measures concerning single-cell safety when limits are violated.

[0020] In another advantageous design of the monitoring unit according to the present invention, the current detection module includes: a current sensor configured to accurately measure the current flow in a single-pool circuit; an evaluation unit configured to analyze and transmit the current value acquired by the current sensor; and an interface configured to enable communication between the current sensor, the evaluation unit, and the single-pool monitoring module and / or the hardware-current monitoring module.

[0021] Furthermore, according to the present invention, a method is proposed for ensuring single-cell safety during the quiescent mode of a battery management system for a battery using a monitoring unit.

[0022] The method includes at least the following steps: a) Measure multiple values ​​of a single-pool line using a current detection module and transmit these values ​​to a single-pool monitoring module and / or a hardware-based current monitoring module. b) Comparison of measured values ​​with pre-programmed limits and / or thresholds is performed using a single-cell monitoring module and / or a hardware-based current monitoring module, wherein limit violations are identified and reported to the battery management system when values ​​exceed or fall below the pre-programmed limits and / or thresholds. c) The battery management system is activated in such a way that it is activated based on limit violations reported by at least the single-cell monitoring module or the hardware-current monitoring module. d) The first time measurement module and / or the second time measurement module are started in such a manner that the start-up of the first time measurement module and / or the second time measurement module occurs simultaneously with the activation of the battery management system, wherein the first time measurement module and / or the second time measurement module transmits one or more signals to the current interruption module after a predetermined delay time, and e) Interrupt all current in a single-pool line using a current interruption module.

[0023] The proposed method incorporates an advantageous monitoring module that employs redundancy to monitor single-cell parameters of the single-cell switch. This is achieved through explicit monitoring of limit values ​​using a single-cell monitoring module, which includes, for example, an autonomous 10Hz limit monitoring mechanism implemented via an integrated circuit (CSCASIC). Indirect monitoring of limit values ​​is performed through autonomous, hardware-based current monitoring using a hardware-current monitoring module. Therefore, the method proposed in this invention allows for reduced diagnostics during vehicle ownership, such as in the event of a fault, without requiring continuous monitoring. Upon identification of a fault by the single-cell monitoring module or the hardware-current monitoring module, a first or second time measurement module is activated, and its status is evaluated after the battery management system is started. Activation of the battery management system occurs simultaneously with the start-up of the first and / or second time measurement modules. The functionality of the first and / or second time measurement modules can be implemented, for example, using separate dedicated integrated circuits or by using analog components, such as capacitors, resistors, and similar components. Analog timing control can be implemented, for example, by capacitor or resistor loading.

[0024] A single-cell monitoring module for measuring voltage, temperature, and current in a single-cell circuit is advantageously programmed to independently transition to wake-up mode during one period and to sleep mode during another. These periods can be predefined or predetermined. Furthermore, all safety-related measurements of the single-cell circuit, such as voltage and temperature, are detected and compared to pre-programmed limits. No action is taken if no violation is identified. If a violation is identified, a report is sent to the battery management system (BMS), specifically a fault report, thereby activating the BMS. Additionally, a first-time measurement module is initiated. After a predefined time has elapsed, the first-time measurement module sends one or more signals to a current interruption module, which subsequently interrupts all current signals. The BMS is adapted to interrupt the signal flow once the BMS is activated and the elapsed time can be read from the first-time measurement module since the violation occurred. Alternatively, monitoring can be performed simultaneously or as an alternative to the single-cell monitoring module via a hardware-based current monitoring module using integrated circuits or analog circuitry, by comparing an amplified shunt voltage to a threshold. Once the limit value is exceeded, the second time measurement module is activated, which in turn activates the battery management system. After a defined wake-up time, the battery management system can also assess the duration of the limit violation in this situation by evaluating the duration of the limit violation by the second time measurement module.

[0025] In an advantageous improvement to the method according to the invention, the single-pool monitoring module is operated at a reduced sampling rate relative to normal operation.

[0026] In an advantageous improvement of the method according to the invention, after activation, the battery management system evaluates the duration of the limit violation by reading from the first time measurement module and / or the second time measurement module.

[0027] In another advantageous improvement of the method according to the invention, the current detection module at least measures and transmits amplified measurements of the shunt voltage, single-cell voltage, single-cell temperature, and / or single-cell current.

[0028] Furthermore, an application of the method according to the present invention inside a lithium-ion power grid battery is proposed.

[0029] Advantages of the present invention The advantages of the described monitoring module are that it enables monitoring of single-cell parameters for a single-cell switch with built-in redundancy. Furthermore, the method according to the invention reduces fault diagnosis, for example, during vehicle operation, without requiring continuous monitoring.

[0030] Furthermore, the solution according to the invention provides redundant monitoring not only for individual cell voltage but also for current. This redundant monitoring ensures compliance with pre-defined safety requirements according to Automotive Safety Integrity Level C (ASIL-C), thereby guaranteeing the reliable and safe functioning of the overall battery system. Additionally, the solution according to the invention offers the advantage of enabling safety monitoring without the use of an active microcontroller. This reduces system complexity and minimizes potential sources of failure.

[0031] Furthermore, the monitoring unit proposed in this invention ensures the effective identification of limit violations and their duration for individual cells in battery and / or single-cell circuits.

[0032] Furthermore, the monitoring unit and the proposed method ensure the lowest possible energy consumption of the battery during the static state.

[0033] Furthermore, the monitoring unit can effectively identify instances where individual battery cells exceed their limits and the duration of such exceedances. The monitoring unit minimizes the risk of functional failures, damage to individual batteries or the entire battery, and safety-related incidents.

[0034] The battery management system of the monitoring module proposed in this invention ensures the effective operation of a single-cell circuit and provides extensive protection against potential damage. Attached Figure Description

[0035] The embodiments of the present invention will be explained in detail with the aid of the accompanying drawings and the following description.

[0036] in: Figure 1 A schematic diagram of the monitoring unit is shown; and Figure 2 A schematic diagram of a method for ensuring single-pool security is shown. Detailed Implementation

[0037] In the following description of embodiments of the invention, the same or similar elements are designated by the same reference numerals, wherein repeated descriptions of these elements are omitted in individual cases. The accompanying drawings are merely schematic illustrations of the subject matter of the invention.

[0038] exist Figure 1 The diagram below shows a simplified version of the monitoring unit 100 for ensuring the safety of a single pool, as proposed in this invention.

[0039] Figure 1 Also shown is a monitoring unit 100 for ensuring single-cell safety during the quiescent mode of the battery management system 112 for the battery, which includes a single-cell line 102, a current detection module 104, a single-cell monitoring module 106 having a wake-up mode and a sleep mode, a hardware-current monitoring module 108, a current interruption module 110, the battery management system 112, and a first time measurement module 114.1 and a second time measurement module 114.2.

[0040] The first time measurement module 114.1 and the second time measurement module 114.2 are used here to detect at least one limit value report in time.

[0041] The single-cell circuit 102 can be configured, for example, as a battery or single-cell assembly in which series circuits, parallel circuits, or combinations of series and parallel circuits interact with each other. As a battery, for example, a lithium-ion battery can be used.

[0042] Depend on Figure 1 It is understood that the current detection module 104 and the single-cell monitoring module 106 interact with the single-cell line 102 to check and / or measure the parameters of the single-cell line 102. Furthermore, from... Figure 1 From the monitoring unit 100, it can be inferred that the current detection module 104 transmits the measurement data not only to the single-cell monitoring module 106 but also to the hardware-current monitoring module 108. The single-cell monitoring module 106 can, for example, be an integrated circuit (ASIC). In contrast, the hardware-current monitoring module 108 can, for example, be configured as a current measurement amplifier incorporating a threshold comparator and additional shunt resistors or Hall elements.

[0043] The function of the first and / or second time measurement modules 114.1, 114.2 is to measure the duration of the report, which is identified either by the single-pool monitoring module 106 and / or by the hardware-current monitoring module 108 when a limit value is exceeded, for example, with respect to the temperature or voltage of the single-pool line 102.

[0044] The first and / or second time measurement modules 114.1, 114.2 can be configured as application-specific integrated circuits (ASICs) or as discrete analog components. Examples of ASICs include semiconductor circuits, also known as CMOS circuits, and field-programmable gate arrays (FPGAs). Discrete analog components can be, for example, capacitors or resistors. Alternatively, the single-cell monitoring module 106, the hardware-current monitoring module 108, the first time measurement module 114.1, and the second time measurement module 114.2 can also be fabricated as integrated circuits (ASICs), with partial integration also possible.

[0045] Furthermore, from in Figure 1 As can be seen from the monitoring unit 100 shown, a first time measurement module 114.1 is connected after the single-pool monitoring module 106 and a second time measurement module 114.2 is connected after the hardware-current monitoring module 108.

[0046] Two time measurement modules, 114.1 and 114.2, are respectively connected to the battery management module 112. Communication between the first time measurement module 114.1 and the battery management system 112, as well as communication between the second time measurement module 114.2 and the battery management system 112, is guaranteed. When the parameters of the single-cell circuit 112 exceed their limits, the battery management system 112 is activated, which is time-correlated with the activation of the first time measurement module 114.1 and / or the second time measurement module 114.2.

[0047] exist Figure 2 The method 200 for ensuring single-pool security according to the present invention is shown in simplified form.

[0048] In the first step of method 200, multiple measurements 202.1 of the single-pool line 102 are taken by the current detection module 104 and transmitted to the single-pool monitoring module 106 and / or the hardware-current monitoring module 108.

[0049] In the second step of method 200, implementation 204 compares the measured value with pre-programmed limit values ​​and / or thresholds via single-cell monitoring module 106 and / or via hardware-current monitoring module 108. Upon determining a limit violation, a corresponding signal is transmitted to battery management system 112.

[0050] In the third step of method 200, the battery management system 112 is activated 206, which is activated 206 due to a limit violation, the limit violation being reported by at least the single-cell monitoring module 106 or the hardware-current monitoring module 108.

[0051] In the fourth step of method 200, the first time measurement module 114.1 and / or the second time measurement module 114.2 are started (208), and more precisely, this is performed simultaneously with the activation (206) of the battery management system 112. In the fifth step, the battery management system 112 is activated (206), wherein the first time measurement module 114.1 and / or the second time measurement module 114.2 transmit one or more signals to the current interruption module 110 after a predetermined delay time.

[0052] In the final step of method 200, all current in the single-pool line 102 is interrupted 210 by the current interruption module 110.

[0053] This invention is not limited to the embodiments described herein and the aspects highlighted therein. Rather, numerous modifications are possible within the scope defined by the claims and which are within the reach of those skilled in the art.

Claims

1. A monitoring unit (100) for ensuring single-cell safety during a quiescent mode of a battery management system (112) for a battery, comprising a single-cell line (102), a current detection module (104), a single-cell monitoring module (106) having a wake-up mode and a sleep mode, a hardware-current monitoring module (108), a current interruption module (110), a battery management system (112), and at least one first time measurement module (114.1) and at least one second time measurement module (114.2), wherein the at least one first time measurement module (114.1) and the at least one second time measurement module (114.2) are configured to detect a maximum duration for which at least one limit value of a measurement value of the single-cell line (102) is violated.

2. The monitoring unit (100) according to claim 1, wherein at least one first time measurement module (114.1) and / or at least one second time measurement module (114.2) are implemented as application-specific integrated circuits or as discrete analog components or are fully or partially integrated into a single-cell monitoring module (106) or a hardware-current monitoring module (108).

3. The monitoring unit (100) according to claim 2, wherein the discrete analog components include at least one capacitor or at least one resistor or at least one integrated timer assembly.

4. The monitoring unit (100) according to any one of the preceding claims, wherein the battery management system (112) is configured to activate measures regarding single-cell safety in the event of a violation of the limit value.

5. The monitoring unit (100) according to any one of the preceding claims, wherein the current detection module (104) comprises: - A current sensor, which is configured to accurately measure the current flow in a single-cell line (102); - Evaluation unit, which is configured to analyze and transmit the current value collected by the current sensor; as well as - An interface is provided for communication between the current sensor, the evaluation unit and the single-cell monitoring module (106) and / or the hardware-current monitoring module (108).

6. A method (200) for ensuring single-cell safety during a quiescent mode of a battery management system (112) for a battery using a monitoring unit (100) according to any one of the preceding claims, comprising at least the following steps: a) Measure (202.1) multiple measurements of the single-pool line (102) by means of the current detection module (104) and transmit (202.2) the measurements to the single-pool monitoring module (106) and / or the hardware-current monitoring module (108). b) The comparison of (204) measured values ​​with pre-programmed limit values ​​and / or thresholds is performed by a single-cell monitoring module (106) and / or a hardware-current monitoring module (108), wherein a limit value violation is identified when the value exceeds or falls below the pre-programmed limit value and / or threshold and is reported to the battery management system (112). c) Activate (206) the battery management system (112), wherein the activation of the battery management system (112) is based on a limit violation reported by at least the single-cell monitoring module (106) or the hardware-current monitoring module (108). d) Starting (208) the first time measurement module (114.1) and / or the second time measurement module (114.2), such that the starting (208) of the first time measurement module (114.1) and / or the second time measurement module (114.2) is simultaneous with the activation (206) of the battery management system (112), wherein the first time measurement module (114.1) and / or the second time measurement module (114.2) transmits one or more signals to the current interruption module (110) after a pre-given delay time, and e) Interrupt all current of the single-pool line (102) by means of the current interruption module (110) (210).

7. The method (200) of claim 6, wherein the single-pool monitoring module (106) is operated at a reduced sampling rate relative to normal operation.

8. The method (200) according to claim 6 or 7, wherein the battery management system (112) evaluates the duration of the limit violation by reading from the first time measurement module (114.1) and / or the second time measurement module (114.2) after activation.

9. The method (200) according to any one of claims 6 to 8, wherein the current detection module (104) measures and transmits at least amplified measurements of shunt voltage, single-cell voltage, single-cell temperature and / or single-cell current.

10. The application of the method (200) according to any one of claims 6 to 9 inside a lithium-ion power grid battery.

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