Zone control unit

Abstract

The zone control unit (10) comprises a processor unit (20) and a power switch arrangement (30). The power switch arrangement (30) comprises a controllable semiconductor switch, a current sensor circuit and an overcurrent detection circuit. The current sensor circuit is designed to provide a measurement signal (ISEN) for the processor unit (20) and the overcurrent detection circuit, representing an output current which the controllable semiconductor switch provides at its first terminal (OUT). The overcurrent detection circuit is designed to deactivate the controllable semiconductor switch for an entire active operating cycle of the ZCU and / or the vehicle if the measurement signal (ISEN) exceeds a predefined first current threshold value (IPEAK). The processor unit (20) is configured to determine, during the active operating cycle of the ZCU or the vehicle, a sum (I2TSUM) of energy values by means of a software program (50) on the basis of the provided measurement signal (ISEN), and, if the sum (I2TSUM) of the energy values exceeds a predefined first energy threshold value (l2TSUM_Threschoid), to deactivate the semiconductor switch.

Description

[0001] 202401631

[0002] 1

[0003] Description

[0004] Zone control unit

[0005] The invention relates to a zone control unit.

[0006] Zone controllers, also known as Zone Control Units (ZCUs), are essential electrical / electronic (E / E) architectural elements in future automotive applications. ZCUs consolidate vehicle functions within a specific physical zone, or local area of ​​the vehicle, near the sensors and actuators. For example, ZCUs are responsible for all control, service, and data management tasks within their respective area. Zone controllers serve as nodes in the vehicle network, handling all power distribution and data connections between the various sensors, peripherals, and actuators within the vehicle's physical zone. The limited number of ZCUs are typically connected to a dedicated Master Control Unit via a high-performance data link.

[0007] ZCUs reduce the complexity and costs of vehicle networks by supporting centralized architectures and the increasing separation of software and hardware. The zone controller architecture particularly simplifies in-vehicle wiring.

[0008] A key aspect of the "zone architecture" is a new, decentralized power distribution system within the vehicle architecture. The ZCUs (Zone Control Units) are intended to function primarily as power distribution hubs. For example, the ZCUs are designed to ensure a regulated power supply for the control units, sensors, and actuators within their respective zones. They are designed to control power consumption decentrally within each zone, thereby improving energy monitoring and diagnostics. The ZCUs are intended to enable software-controlled power distribution, distributing power according to the priority of consumers. This intelligent power distribution allows for adjustments to the lengths, diameters, and other parameters of the vehicle's electrical system.

[0009] 2

[0010] The complexity of the cable harnesses can be reduced and a redundant power supply can be implemented to cover safety requirements.

[0011] A key requirement for enabling such decentralized, intelligent power distribution is replacing conventional fuses with more flexible ones. Currently, so-called electronic fuses (e-fuses) are being developed for this purpose. These electronic fuses are typically semiconductor switches that emulate a protection curve with a predefined profile, such as an i2t curve, using a hardware circuit. Electronic fuses are also referred to as intelligent fuses. Such electronic fuses are complex and require a significant amount of space. In addition to their high cost, their large footprint is a particular problem, as it severely limits the number of loads that such a central control unit (CCU) can handle.

[0012] The purpose of the present disclosure is therefore to provide a zone control unit that enables the safe and flexible operation of a large number of connected loads and can be provided with minimal hardware effort.

[0013] The problem is solved by the features of the independent patent claims. Advantageous embodiments are characterized in the dependent claims.

[0014] According to a first aspect, the problem is solved by a zone control unit for a vehicle, comprising a processor unit and a power switch arrangement. The vehicle is preferably a motor vehicle. The vehicle can be an internal combustion engine vehicle, a hybrid vehicle (HEV), or a battery electric vehicle (BEV). 202401631

[0015] 3

[0016] The power switch assembly includes a controllable semiconductor switch, a driver circuit, a current sensor circuit, and an overcurrent detection circuit.

[0017] The controllable semiconductor switch can be connected to a load via a connecting cable at one terminal and directly or indirectly to a vehicle power source at a second terminal. The controllable semiconductor switch is configured to supply power to the load in a closed state and to interrupt the power supply to the load in an open state. The driver circuit is connected to a control input of the controllable semiconductor switch.

[0018] The current sensor circuit is configured to provide a measurement signal for the processor unit and the overcurrent detection circuit, representative of an output current provided by the controllable semiconductor switch at the first terminal. The overcurrent detection circuit is configured, when the measurement signal exceeds a predetermined first current threshold, to control the driver circuit such that the controllable semiconductor switch is in an open state, specifically for an entire active operating cycle of the ZCU and / or the vehicle.

[0019] The processor unit is designed to determine energy values ​​for predetermined measurement intervals using a software program function, depending on the provided measurement signal, and to determine a sum of energy values ​​based on the energy values ​​of the respective measurement intervals. If the sum of the energy values ​​exceeds a predetermined first energy threshold, it provides a first driver signal for the driver circuit, which causes the semiconductor switch to transition from a closed to an open state.

[0020] The zone control unit as disclosed is based on the understanding that protecting the load / consumer has different requirements. The first requirement is to ensure an immediate interruption of the 202401631

[0021] 4

[0022] The circuit must be interrupted when the current exceeds the first current threshold. The interruption must occur very quickly (response time in the microsecond range). For this reason, the monitoring and shutdown circuitry is implemented in hardware. Only the current output current level is considered.

[0023] The second requirement is to prevent overheating, particularly of the connecting cable. Overheating depends primarily on accumulated thermal energy and not on a short-term peak current. The monitoring system takes the accumulated thermal energy (current level and time) into account.

[0024] The two requirements therefore have very different timeframes. Monitoring the accumulated energy is implemented cost-effectively in software without additional hardware. The software algorithm provides a trigger signal that is used to deactivate the output of the semiconductor switch via the driver control. Timely interruption of the circuit protects the circuit while simultaneously allowing for dynamic load current, such as inrush current.

[0025] Supplying the consumer via the circuit breaker arrangement is unnecessary, since most consumers, especially

[0026] Low-voltage consumers do not require a power supply in a vehicle when parked.

[0027] In at least one advantageous embodiment of the ZCU, the processor unit is configured to provide a second driver signal at the control output if, after the semiconductor switch has been opened due to the sum of the energy values ​​exceeding the first energy threshold during the same active operating cycle of the ZCU or the vehicle, an updated sum of the energy values ​​falls below a predetermined second energy threshold. This second driver signal causes the semiconductor switch to return from the open state to a closed state. 202401631

[0028] 5. The second energy threshold is lower than the first energy threshold. The second energy threshold can, for example, have the value zero.

[0029] This allows the connection to the consumer to be reactivated after a "cooling-off phase." This has the advantage that temporary disturbances and / or high load fluctuations do not immediately cause the ZCU and / or the vehicle to enter a fail-safe or fail-operational state. Energy distribution can be designed more flexibly, and safety margins in the system design can be smaller. Preferably, if the controllable semiconductor switch has been deactivated / opened several times during the same active operating cycle, for example, nth time, because the sum of the energy values ​​has exceeded the first energy threshold, the semiconductor switch is deactivated / opened for the entire duration of the active operating cycle the next time the sum of the energy values ​​is exceeded.

[0030] In at least one advantageous embodiment, the overcurrent detection circuit is designed to control the driver circuit when the measurement signal exceeds a predetermined first current threshold value, such that the controllable semiconductor switch has an open state for an entire active operating cycle of the ZCU and / or the vehicle.

[0031] In at least one advantageous embodiment of the ZCU according to the first aspect, the processor unit is configured to provide a second driver signal for the driver circuit during the same active operating cycle of the ZCU or the vehicle, after a predetermined duration following the opening of the semiconductor switch due to exceeding the first energy threshold by the sum of the energy values. This second signal causes the semiconductor switch to transition from the open state back to a closed state. The duration can be arbitrarily defined. This increases flexibility; however, there is a risk that the duration of the "cooling-off phase" will be too short.

[0032] 6 or is chosen to be too long. In the method described above, the duration of the "cooling phase" depends essentially on the predetermined first energy threshold and a predetermined nominal current.

[0033] In at least one advantageous embodiment of the ZCU, the respective energy values ​​are determined as a function of the square of an output current value determined for the respective measurement interval. Specifically, the respective energy values ​​are determined as a function of the square of the determined output current and a predetermined measurement interval duration. Furthermore, the respective energy values ​​are preferably also determined as a function of a predetermined nominal current value.

[0034] In at least one advantageous embodiment of the ZCU, the respective energy value of one of the measurement intervals is equal to the respective total energy value of the measurement interval minus a nominal energy value, where the respective total energy value is equal to the square of the output current value determined for the respective measurement interval multiplied by the predetermined measurement interval duration, and the nominal energy value is equal to the square of a predetermined nominal current value multiplied by the measurement interval duration. Thus, for monitoring purposes, not only the total accumulated thermal energy based on the current level and time is relevant, but, in order to mimic the protection curve of a conventional fuse, the square of the nominal current value is subtracted from the square of the determined output current value.

[0035] In at least one advantageous embodiment of the ZCU, the processor unit is configured to determine a ratio between the respective measured output current value and the specified nominal current value and, if the ratio is greater than a specified threshold, to determine the sum of the energy values ​​depending on an integration factor. The integration factor can, for example, be a constant factor, in particular a constant factor greater than one, or correspond to the ratio of the output current value to the specified nominal current value. The integration factor can be 202401631

[0036] 7. For example, it can be multiplied by the energy values ​​of the respective measurement intervals, especially those measurement intervals where the ratio is greater than the specified threshold. Advantageously, this means that the first energy threshold is reached more quickly, thus better protecting more sensitive electronic components such as PCB traces or MOSFETs.

[0037] In at least one advantageous embodiment of the current control unit (CCU), the output current of the semiconductor switch is detected indirectly. That is, the output current to be determined does not flow through the current sensor circuit. This has the advantage that the circuit from the power source to the load and back is not interrupted by the current sensor circuit.

[0038] In at least one advantageous embodiment of the ZCU, the current sensor circuit for providing the measurement signal includes a current generator configured to produce a current proportional to the output current of the controllable semiconductor switch.

[0039] In at least one advantageous embodiment of the ZCU, the current sensor circuit is integrated on the same semiconductor chip as the controllable semiconductor switch. This allows for savings in both cost and space.

[0040] In at least one advantageous embodiment of the ZCU, the controllable semiconductor switch comprises a power metal oxide semiconductor field-effect transistor.

[0041] In at least one advantageous embodiment of the ZCU, the ZCU has several of the power switch arrangements and the processor unit is configured to control the respective driver circuits of the power switch arrangements and to receive the measurement signals of the respective current sensor circuits.

[0042] The problem is solved according to a further aspect by a method for operating a circuit breaker arrangement of a zone control unit, which is a circuit breaker arrangement with a controllable semiconductor switch, a 202401631

[0043] 8

[0044] The controllable semiconductor switch comprises a driver circuit and a current sensor circuit. It can be connected to a load via a connecting cable at one terminal and directly or indirectly to a vehicle power source at the other. The controllable semiconductor switch is configured to provide power to the load in a closed state and to interrupt the power supply to the load in an open state. The current sensor circuit provides a measurement signal to the processor unit, representing an output current supplied by the controllable semiconductor switch at the first terminal. The power switch assembly may additionally include an overcurrent detection circuit.

[0045] The procedure includes the following steps:

[0046] - Receipt of the measurement signal that is representative of the output current provided by the controllable semiconductor switch at the first terminal,

[0047] - Determining energy values ​​for predefined measurement intervals depending on the provided measurement signal,

[0048] - Determining a sum of the energy values ​​depending on the determined energy values ​​of the respective measurement intervals and, if the sum of the energy values ​​exceeds a predetermined first energy threshold, providing a first driver signal for the driver circuit, which causes the semiconductor switch to transition from a closed to an open state, whereby a current sum of the energy values ​​is determined recursively and an energy value to be added is added to the previously determined sum of energy values ​​depending on a ratio of a current output current value to a predetermined nominal current value.

[0049] In at least one advantageous embodiment of the method, if, after the semiconductor switch is opened due to the first energy threshold being exceeded by the sum of the energy values ​​during the same active operating cycle of the ZCU or the vehicle, an updated sum of the energy values ​​is set to a predetermined second energy threshold 202401631

[0050] If the value falls below 9, a second driver signal is provided for the driver circuit, causing the semiconductor switch to return from the open state to a closed state.

[0051] In at least one advantageous embodiment of the method, during the same active operating cycle of the ZCU or the vehicle, after a predetermined duration following the opening of the semiconductor switch due to the first energy threshold being exceeded by the sum of the energy values, a second driver signal is provided at the control output, which causes the semiconductor switch to transition from the open state back to a closed state.

[0052] In at least one advantageous embodiment of the method, the respective energy values ​​are determined as a function of the square of an output current value determined for the respective measurement interval. In particular, the respective energy values ​​are determined as a function of the product of the square of the output current and a predetermined measurement interval duration.

[0053] In at least one advantageous embodiment of the method, the respective energy values ​​are additionally determined depending on a given nominal current value.

[0054] In at least one advantageous embodiment of the method, the respective energy value of one of the measurement intervals is equal to the respective total energy value of the measurement interval minus a nominal energy value, and the respective total energy value is equal to the square of the output current value determined for the respective measurement interval, multiplied by the predetermined measurement interval duration, and the nominal energy value is equal to the square of a predetermined nominal current value multiplied by the measurement interval duration. 202401631

[0055] 10

[0056] In at least one advantageous embodiment of the method, if the ratio of the current output current value to the specified nominal current value is greater than the specified threshold value, the energy value to be added is multiplied by the ratio to the previously determined sum of energy values.

[0057] According to a third aspect, the problem is solved by a computer program comprising instructions which, when the program is executed by a processor unit of a zone control unit comprising a power switch arrangement with a controllable semiconductor switch, a driver circuit and a current sensor circuit, cause the processor unit to execute the method for operating a power switch arrangement of a zone control unit or an advantageous embodiment of the method.

[0058] According to a fourth aspect, the task is solved by a computer program product comprising a computer program according to the third aspect.

[0059] The present revelation is described below with reference to the figures.

[0060] The description of the items listed here is not limited to the individual specific embodiments. Features of different embodiments can be combined – insofar as technically feasible – to form further embodiments. For example, variations or modifications described with regard to one embodiment may also be applicable to other embodiments, unless otherwise stated.

[0061] It shows: 202401631

[0062] 11

[0063] Figure 1 shows an exemplary block diagram of a embodiment of a zone control unit,

[0064] Figure 2 shows an example flowchart for a program to operate a circuit breaker arrangement of the zone control unit,

[0065] Figures 3a to 3c each show a current waveform at the output of the circuit breaker arrangement and

[0066] Figure 4 shows exemplary current-time characteristic curves for a commercially available fuse, for a cable and for the circuit breaker arrangement as disclosed.

[0067] In the figures, the same reference symbols are used for elements with essentially the same function; however, these elements do not have to be identical in every detail.

[0068] It should be noted that when an element is described as "connected" to another element, the element may be directly connected to the other element, or there may be intermediate elements. Conversely, when an element is described as "directly" "connected" to another element, no intermediate elements are present.

[0069] Figure 1 shows an exemplary block diagram of a embodiment of a zone control unit.

[0070] The zone control unit (ZCU) 10 comprises a processor unit 20. The processor unit 20 includes, for example, a microcontroller (pC). Alternatively, the processor unit 20 can include a microprocessor. The processor unit 20 also includes a program memory and preferably a data memory. The program memory and / or the data memory can be located within the microcontroller or microprocessor, or externally from the microcontroller or microprocessor. 202401631

[0071] 12

[0072] The ZCU is designed to provide a power supply for various loads / consumers. Therefore, the ZCU has, for example, a first supply connection VBD1 and a second supply connection VBD2. The first supply connection VBD1 is preferably connected to the vehicle's low-voltage battery and can therefore also be referred to as a terminal 30 connection. The voltage of the vehicle's low-voltage system can be, for example, 12 V, 24 V, or 48 V. The second supply connection VBD2 is, for example, a redundant supply connection and is connected, for example, to a high-voltage / low-voltage DC / DC converter in the vehicle, which converts the high-voltage voltage of a traction battery into a desired low-voltage voltage, for example, 12 V, 24 V, or 48 V.

[0073] The zone control unit 10 comprises at least one circuit breaker assembly 30. The circuit breaker assembly 30 has a controllable semiconductor switch configured to provide power to a load 40, depending on a control signal from the processor unit. The load can be inductive, capacitive, and / or resistive. The load 40 can be, for example, an actuator, a sensor, a lighting system, etc. In addition to functioning as a circuit breaker, the semiconductor switch can also function as an on / off switch. The load can also include another control device (ECU).

[0074] The power switch arrangement 30 has a driver circuit, an overcurrent protection circuit and a current sensor for each controllable semiconductor switch.

[0075] Optionally, to improve the safe operation of the respective semiconductor switch, the circuit breaker assembly 30 can include a temperature sensor and / or an over-temperature protection circuit and / or an overvoltage limiter and / or a voltage sensor and / or reverse polarity protection. 202401631

[0076] 13

[0077] Furthermore, the circuit breaker arrangement 30 can include a supply voltage monitoring and / or an overvoltage detection circuit and / or an ESD protection circuit and a reset circuit.

[0078] The circuit breaker arrangement 30 is characterized in particular by its very simple design. This is possible because measures that enable a power supply or voltage supply to the connected load 40 in a parking mode of the vehicle are omitted.

[0079] A first output OUT of the semiconductor switch or power switch assembly 30 is connectable to, or already connected to, the load 40 via a connecting line. The power switch assembly or semiconductor switch is configured to provide a power supply to the load 40. The controllable semiconductor switch is configured to provide a power supply to the load 40 in a closed state and to interrupt the power supply to the load 40 in an open state.

[0080] A control input of the controllable semiconductor switch is connected to the driver circuit. The semiconductor switch comprises, in particular, a transistor, preferably a power MOSFET, for example a DMOS (double-diffused metal-oxide semiconductor field-effect transistor). When using a power MOSFET, the gate terminal of the power MOSFET, for example, forms the control input.

[0081] The semiconductor switch, together with the connected load, functions in particular as a high-side power switch.

[0082] The current sensor circuit of the respective semiconductor switch is configured to provide a measurement signal ISEN for the processor unit 20, which is representative of 202401631

[0083] 14 an output current that the controllable semiconductor switch provides at the first output OUT.

[0084] The current sensor circuit is preferably configured to indirectly measure the output current of the semiconductor switch. This has the advantage that the circuit does not need to be interrupted to insert the current sensor circuit in series with the other components.

[0085] The current sensor circuit includes, for example, a current generator configured to produce a current proportional to the output current of the controllable semiconductor switch. The current in the power MOSFET (semiconductor switch) is measured, for example, by a "sense MOSFET" integrated on the same chip. This sense MOSFET is typically a small mirrored version of the power MOSFET, with its drain and gate terminals connected to those of the power MOSFET.

[0086] This makes it possible to determine the current flowing in or through the connecting line very easily, very cost-effectively and with minimal space requirements.

[0087] In addition to the current sensor circuit, the circuit breaker arrangement 30 preferably includes an overcurrent detection circuit. The current sensor circuit is configured to provide the measurement signal for the overcurrent detection circuit, and the overcurrent detection circuit is configured when the measurement signal exceeds a predetermined first current threshold lp. ea If k, representing a maximum permissible overcurrent for a short period, is exceeded, the controllable semiconductor switch is deactivated for the entire active operating cycle of the ZCU or the vehicle. The active operating cycle of the vehicle can also be referred to as the driving cycle, whereby short-term stops, e.g., stops at traffic lights, are also included in the driving cycle.

[0088] The processor unit 30 is configured to calculate a sum I2TSUM of 202401631 using a software program 50, depending on the provided measurement signal ISEN.

[0089] 15

[0090] Energy values ​​are determined, and if the sum I2TSUM of the energy values ​​exceeds a predefined first energy threshold I2TSUM_Threshold, a driver signal is provided that causes the semiconductor switch to enter and remain in an open state. Subsequently, for example, during the same active operating cycle of the ZCU or the vehicle, if an updated sum I2TSUM of the energy values ​​falls below a predefined second energy threshold I2TSUM_COOL_OFF, the semiconductor switch is reactivated, where the second energy threshold I2TSUM_COOL_OFF is lower than the first energy threshold I2TSUM_Threshold-

[0091] Figure 2 shows an exemplary flowchart for an embodiment of a program for operating the circuit breaker arrangement 30. The program is preferably executed by the processor unit 20. The program is executed, for example, as application software by the processor unit 20.

[0092] The program is started in step S01. Variables are initialized in step S01, for example.

[0093] In step S03, an output current measurement value ILOAD is first read. The processor unit 20, for example, has an analog-to-digital converter configured to convert the measurement signal ISEN, provided by the current sensor circuit of the circuit breaker arrangement 30, into digital measured values. Furthermore, the processor unit 20 can include, as part of basic software, a program configured to determine the output current values ​​ILOAD ZU based on the digital measured values.

[0094] In step S05, the program checks whether the output current measurement ILOAD exceeds a nominal current value INOM, which, for example, is equal to a predefined maximum continuous current for the output current of the power switch assembly 30 or the semiconductor switch. If the output current measurement ILOAD does not exceed the nominal current value INOM, the program continues in step S03. If the input output current measurement ILOAD exceeds the nominal current value INOM, the program continues in step S07.

[0095] 16 continued, in which an energy value I2T is determined according to the following equation (1 ):

[0096] In step S07, the square of the output current measurement ILOAD is determined. A value, preferably a constant value, which is in particular equal to the square of the nominal output current INOM, is subtracted from the square of the output current measurement ILOAD, and the result is multiplied by a factor. The factor preferably represents a normalized time unit, e.g., 0.001, which corresponds to a normalized time unit of 1 ms. Alternatively, the time unit can also be 0.5 ms, 2 ms, 5 ms, or 10 ms. Alternatively, a constant value that already takes the normalized time unit into account can be used.

[0097] In step S09, a sum I2TSUM of the energy values ​​is determined. The sum of the energy values ​​is determined, for example, recursively according to the following equation (2):

[0098] I2TSUM = I2TSUM, i-1 + I2T

[0099] In step S11, the sum I2TSUM of the energy values ​​is compared with a first energy threshold I2TSUM_ -Threshold. The first energy threshold I2TSUM_Threshold is derived, for example, from a desired profile of a protection curve that the circuit breaker arrangement 30 is intended to implement (see Figure 4). The protection curve can, for example, be selected so that it corresponds, at least section by section, approximately to a protection curve of a standard fuse.

[0100] If, in step S11 (Figure 2), it is determined that the sum I2TSUM of the energy values ​​is less than the first energy threshold l2TsuM_Threshoid, in step S13 it is checked whether the sum I2TSUM of the energy values ​​is greater than or equal to 0. If the sum I2TSUM of the energy values ​​is greater than or equal to 0, 202401631

[0101] 17. The program continues in step S15. In step S15, another output current measurement ILOAD is read in, and the program then continues in step S07. Since the additional output current measurement ILOAD can be smaller than the nominal current value INOM, the sum I2TSUM, the energy value, can also become smaller again.

[0102] If in step S13 it is determined that the sum I2TSUM of the energy values ​​is negative, the sum of the energy values ​​is reinitialized, i.e. set to zero, and the program continues in step S03.

[0103] If in step S11 it is detected that the sum of the energy values ​​I2TSUM is equal to or greater than the first energy threshold l2TsuM_Threshoid, in step S17 an output of a first driver signal for the driver circuit is triggered, which causes the semiconductor switch to transition from a closed to an open state.

[0104] To prevent, for example, a measurement error causing the vehicle to enter limp mode or a safer operating state, it should be ensured that a check is first performed to determine whether the controllable semiconductor switch has already been deactivated once or several times during the current active operating state of the central control unit. For example, it could be stipulated that permanent deactivation of the controllable semiconductor switch only occurs after a predetermined number of deactivations have already been carried out.

[0105] In an optional configuration, the semiconductor switch can therefore be permanently deactivated for an active operating cycle of the ZCU or the vehicle only after it has already been deactivated several times during the same active operating cycle. In this optional configuration, the semiconductor switch can be reactivated after a "cooling-off phase".

[0106] For this purpose, in step S17, for example, the counter value I2TTRIP of a counter can be incremented. The counter value I2TTRIP of the counter thus indicates how frequently the 202401631

[0107] 18

[0108] Semiconductor switches were already deactivated during a continuous active operating state of the ZCU or vehicle.

[0109] In step S19, the counter reading is compared to a predefined third threshold value, I2TTRIP_Threshold. If the counter reading I2TTRIP is less than the third threshold value, I2TTRip_Threshoid, a cooling-off phase is initiated. If the counter reading I2TTRIP is greater than the third threshold value, I2TTRip_Threshoid, the semiconductor switch remains deactivated.

[0110] The cooling phase includes, for example, step S21 in which a current output current measurement ILOAD is read, and steps S23 and S25 in which the energy value I2T and the sum of the energy values ​​I2TSUM, respectively, are determined and updated based on the read output current measurement ILOAD. If the sum I2TSUM of the energy values ​​determined in step S25 is less than or equal to a predefined fourth threshold I2TSUM_COOL_OFF (checked in step S27), a second driver signal is triggered in step S29 for the driver circuit, causing the semiconductor switch to transition from the open state to a closed state. The program then continues in step S03.

[0111] Alternatively, the cooling phase can be implemented by waiting a predetermined duration from step S19 until the program continues in step S29.

[0112] In a further optional embodiment, it can be provided that if the output current values ​​ILOAD are significantly larger than the nominal current values ​​INOM, then, for example, when summing, the respective associated energy values ​​I2T are weighted by a factor, for example, the respective ratio of output current value ILOAD TO nominal current value INOM.

[0113] Step S09 can be modified by introducing an integration factor and executed as follows: 202401631

[0114] 19

[0115] I2TSUM = I2TSUM + I2T*R where, for example, the following holds:

[0116] R = Output current values ​​ILOAD / Z Nominal current values ​​INOM if output current values ​​ILOAD / Z Nominal current values ​​INOM >= 2 and otherwise R = 1 , or where:

[0117] R = 1 if output current values ​​ILOAD / / nominal current values ​​INOM < 2 and

[0118] R= 2 if output current values ​​ILOAD / Z nominal current values ​​INOM >=2.

[0119] Figures 3a, 3b and 3c show exemplary current waveforms provided at the first output OUT of the circuit breaker arrangement 30.

[0120] Figure 3a shows an example of the current waveform at the first output OUT of the circuit breaker arrangement 30 when, for example, the load 40 connected to the first output OUT is switched on. The output current briefly rises above the nominal current value INOM, which corresponds in particular to a predetermined maximum permissible continuous current, and then falls below the nominal current value INOM. Since the current does not exceed the first current threshold value lp eaIf k, which preferably corresponds to a maximum permissible peak current, is exceeded, the overcurrent protection circuit does not trip. The processor 20 detects that the current is rising above the nominal current value INOM and starts calculating the sum I2TSUM of the energy values. However, since the sum I2TSUM of the energy values ​​exceeds the first threshold lp ea k does not exceed, 202401631

[0121] 20 The active semiconductor switch remains in the active state (closed or conducting state).

[0122] Figure 3b shows an example of the current waveform at the first output OUT of the power switch arrangement 30 when, for example, a short circuit occurs in the load, causing the output current to rise above the first current threshold Ipeak. In this case, the overcurrent protection circuit trips and the switchable semiconductor switch is permanently deactivated for the current operating cycle.

[0123] Figure 3c shows an example of the current waveform at the first output OUT of the power switch arrangement 30 when, for example, an external EMC interference affects the connecting line. In this case, the output current rises above the nominal current value INOM, but remains below the first current threshold value Ipeak. The processor 20 detects that the output current has risen above the nominal current value INOM and starts calculating the sum I2TSUM of the energy values. Since the excessive current flows for a longer period, the sum I2TSUM of the energy values ​​exceeds the first energy threshold value l2TsuM_Threshoid after a certain tripping time, and the switchable semiconductor switch is deactivated.

[0124] Figure 3c shows a simplified case in which the power switch arrangement 30 or the controllable semiconductor switch is not reactivated and is returned to a conducting state after a “cooling phase”.

[0125] Figure 4 shows exemplary current-time characteristic curves for a standard fuse, for a cable, and for the circuit breaker arrangement according to the disclosure (with and without a reduction of the current limit). The current-time characteristic curves can also be referred to as "protection curves".

[0126] A first characteristic curve K1 shows an exemplary time-current characteristic curve for the circuit breaker arrangement according to the disclosure, in the case where the 202401631

[0127] 21 respective energy values ​​are taken into account unweighted, or where no reduction of the current limit takes place.

[0128] For example, the following function is used for the first characteristic curve K1:

[0129] I =M IN (ROOT L(( I2TSUM_ .Threshold / t)+ I 2 NOM)JPEAK) where the variable t is time.

[0130] A second characteristic curve, K2, shows an exemplary time-current characteristic for the circuit breaker arrangement in the case where the "current limit" for high output current values ​​is reduced. This reduction is achieved by introducing a factor or integration factor.

[0131] For example, the following function is used for characteristic curve K2: l=M IN(SQRT((l2TsuM_Threshoid / (t F))+( I 2 NOM)); IPEAK) where F represents the factor or integration factor. For simplification, if the ratio R of the measured current I to the nominal current value INOM exceeds two, the factor F is increased from F = 1 to F = 2.

[0132] A third characteristic curve, K3, shows the time-current characteristic of a standard fuse for automotive applications.

[0133] A fourth characteristic curve, K4, shows the time-current characteristic of a commercially available cable for the automotive sector.

[0134] The primary goal of the I2T protection curve is wire protection. However, there is also a need to protect sensitive electronic components, such as circuit traces on a printed circuit board or the power switch itself, for example, a FET. Self-destruction of the switch, i.e., its functioning as a protective element, is not permissible. At higher currents, where there is a risk of [202401631]

[0135] Since there is a risk of thermal events affecting the sensitive electronic components (22), the output current must be deactivated earlier. Therefore, the I2T protection curve must be adjusted to meet this requirement. Such an adjustment can be implemented as a purely software-based solution.

[0136] A derating function enables faster integration of the I2T calculation at higher load currents. The difference between an I2T protection curve without derating (characteristic curve K1) and with derating (characteristic curve K2) is shown in Figure 4.

[0137] Within such a reduction function, an integration factor F can be introduced into the original I²T calculation if the ratio between a measured or determined output current value and a nominal current value exceeds a calibratable threshold. In other words, the integration factor F can have a value other than one if the aforementioned ratio is greater than the specified threshold, and otherwise the integration factor F is set to one. Typically, the value other than one is greater to enable faster integration. For example, an integration factor F of two can halve the tripping time.

[0138] The integration factor determined in this way is then introduced into the original I²T calculation. In the scheme shown in Figure 2, if the query in step S05, which asks whether the output current value ILOAD is above the nominal current value INOM, is answered positively, an additional step can be introduced in which the integration factor F is calculated. Such a calculation can, for example, include the previously described comparison of the ratio between the output current value and the nominal current value with a threshold value, and the determination of the integration factor F based on this comparison. In the subsequent calculation of I²T in step S07, the integration factor F is then taken into account as an additional factor: (ILOAD 2 - INOM 2 )*T*F. Alternatively, the integration factor could also be taken into account in step S09: I2TSUM = I2TSUM + I2T*F. 202401631

[0139] 23

[0140] As a comparison of curve K1 (without reduction) and K2 (with reduction) shows, the integration factor F allows sensitive electronic components to be protected at higher currents by allowing the circuit breaker to trip earlier. Functionality with respect to inrush currents is still guaranteed because the corresponding inrush current curves lie below curves K1 and K2 and maintain a sufficient distance from curve K2 (with reduction).

[0141] 202401631

[0142] 24

[0143] Reference sign

[0144] 10 zone control unit, 20 processor unit

[0145] 30 Circuit breaker arrangement

[0146] 40 consumers

[0147] 50 software programs

[0148] ILOAD output current value INOM nominal current value

[0149] I PEAK first current threshold

[0150] ISEN measurement signal

[0151] I2T energy value

[0152] I2TSUM sum of energy values ​​l2TsUM_Threshold first energy threshold

[0153] I2TSUM_COOL_OFF second energy threshold

[0154] T Measurement interval duration

Claims

202401631 25 Patent claims 1. Zone control unit, ZCU, (10) for a vehicle, wherein - the zone control unit (10) comprises a processor unit (20) and a power switch assembly (30), - the circuit breaker arrangement (30) comprises a controllable semiconductor switch, a driver circuit, a current sensor circuit and an overcurrent detection circuit, - the controllable semiconductor switch can be connected to a consumer (40) via a connecting line via a first connection (OUT) and to a vehicle energy source directly or indirectly via a second connection (VBDx), - the controllable semiconductor switch is configured to provide a power supply to the consumer (40) in a closed state or to interrupt the power supply to the consumer (40) in an open state, - the driver circuit is connected to a control input of the controllable semiconductor switch, - the current sensor circuit is configured to provide a measurement signal (ISEN) for the processor unit (20) and the overcurrent detection circuit, which is representative of an output current provided by the controllable semiconductor switch at the first terminal (OUT), - the overcurrent detection circuit is configured to control the driver circuit in such a way that the controllable semiconductor switch has an open state when the measurement signal (ISEN) exceeds a predetermined first current threshold (IPEAK), - the processor unit (20) is set up by means of a software program (50) to determine energy values ​​(I2T) for predefined measurement intervals depending on the provided measurement signal (ISEN) and, depending on the energy values ​​(I2T) of the respective measurement intervals, to determine a sum (I2TSUM) of energy values ​​and, if the sum (I2TSUM) of the energy values ​​exceeds a predefined first energy threshold (I2TsuM_Threschoid), a first driver signal for the driver circuit 202401631 26, which causes the semiconductor switch to transition from a closed to an open state.

2. Zone control unit (10) according to claim 1, wherein the processor unit (20) is configured to provide a second driver signal to the driver circuit when, after the opening of the semiconductor switch due to exceeding the first energy threshold (I2TSUM_Threschoid) by the sum (I2TSUM) of the energy values ​​during the same active operating cycle of the ZCU (10) or the vehicle, an updated sum (I2TSUM) of the energy values ​​falls below a predetermined second energy threshold (I2TSUM_COOL_OFF), which causes the semiconductor switch to return from the open state to a closed state.

3. Zone control unit (10) according to claim 1, wherein the processor unit (20) is configured to provide a second driver signal at the control output during the same active operating cycle of the ZCU (10) or the vehicle after a predetermined duration following the opening of the semiconductor switch due to the first energy threshold (I2TsuM_Threschoid) being exceeded by the sum (I2TSUM) of the energy values, which causes the semiconductor switch to return from the open state to a closed state.

4. Zone control unit (10) according to one of the preceding claims, wherein the respective energy values ​​(I2T) are determined depending on a square of an output current value (ILOAD) determined for the respective measurement interval.

5. Zone control unit (10) according to claim 4, wherein the respective energy values ​​(I2T) are determined depending on a product of the respective determined square and a predetermined measurement interval duration (T). 202401631 27 6. Zone control unit (10) according to claim 4 or 5, wherein the respective energy values ​​(I2T) are additionally determined depending on a predetermined nominal current value (INOM).

7. Zone control unit according to claim 6, wherein a respective energy value (I2T) of one of the measurement intervals is equal to a respective total energy value of the measurement interval minus a nominal energy value, and the respective total energy value is equal to the square of the output current value (ILOAD) determined for the respective measurement interval multiplied by the predetermined measurement interval duration (T), and the nominal energy value is equal to a square of a predetermined nominal current value (INOM) multiplied by the measurement interval duration (T).

8. Zone control unit (10) according to one of the preceding claims, wherein the processor unit (20) is configured to determine a ratio between the respective determined output current value (ILOAD) and the specified nominal current value (INOM) by means of the software program (50) and, if the ratio is greater than a specified threshold value, to determine the sum (I2TSUM) of the energy values ​​depending on an integration factor.

9. Zone control unit (10) according to one of the preceding claims, wherein the output current of the semiconductor switch is indirectly detected.

10. Zone control unit (10) according to one of the preceding claims, wherein the current sensor circuit for providing the measurement signal comprises a current generator configured to generate a current proportional to the output current of the controllable semiconductor switch.

11. Zone control unit (10) according to claim 10, wherein the current sensor circuit is integrated on the same semiconductor chip as the controllable semiconductor switch. 202401631 28 12. Zone control unit (10) according to any one of the preceding claims, wherein the controllable semiconductor switch comprises a power metal-oxide-semiconductor field-effect transistor.

13. Zone control unit (10) according to any one of the preceding claims, wherein the The zone control unit (10) has several of the circuit breaker arrangements (30), and the processor unit (20) is configured to control the respective driver circuits of the circuit breaker arrangements (30) and to receive the measurement signals (ISEN) of the respective current sensor circuits.

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