1920 results about "Current threshold" patented technology

The invention discloses a battery thermal runaway detection system based on an early warning function, and relates to the technical field of battery thermal runaway, and the system comprises a supervision center which is used for carrying out the real-time supervision of the data information of a plurality of batteries, carrying out the early warning of the time data of the battery thermal runaway, and facilitating the timely issuing of warning information and notification announcements, and a monitoring device which is used for monitoring the data information of a plurality of batteries. The monitoring device is used for collecting thermal runaway parameters of each detection node of a plurality of batteries, the thermal runaway parameters comprise battery voltage, temperature, current and pressure, and the protection device is used for carrying out delayed protection operation on the monitoring device. The battery thermal runaway detection system based on the early warning function establishes a thermal runaway early warning model by fusing multi-parameter data of heat, force, electricity and the like and historical data of a thermal runaway phenomenon and by utilizing various learning algorithms, monitors battery parameters and sets simple judgment standards and threshold values such as a non-working state current threshold value and the like, so that the battery thermal runaway early warning model is established. Early detection of battery thermal runaway is realized, and monitoring and early warning effects are achieved.

The invention discloses a man-machine exoskeleton cooperation method based on multi-modal signal fusion, and relates to the technical field of exoskeleton program control. The method comprises the following steps that man-machine exoskeleton driving pre-pressure cold and hot mutation analysis is conducted in combination with man-machine exoskeleton man-machine cooperation components; and performing memory alloy spring pre-pressure optimization adjustment in combination with a man-machine exoskeleton driving pre-pressure cold and hot mutation analysis result. According to the invention, cold chain exoskeleton cooperative control is realized through multi-mode signal fusion, and three-level regulation and control are implemented based on a current threshold value and a myoelectricity state: graded current rising / falling and safety early warning are carried out in case of abnormal current; dynamic gain compensation or joint retardation protection is carried out when myoelectricity is abnormal; according to the man-machine exoskeleton cooperative control method and the man-machine exoskeleton cooperative control system, the effect of improving the accuracy of man-machine exoskeleton cooperative control for coping with cold-chain logistics is achieved, and the problem that the accuracy of man-machine exoskeleton cooperative control for coping with cold-chain logistics is disabled in the prior art is solved.

The invention relates to the technical field of electrical performance testing, in particular to a water supply equipment electrical performance detection system based on artificial intelligence, which comprises an electrical parameter acquisition module, an energy efficiency analysis module, an insulation performance evaluation module and a comprehensive diagnosis module. According to the invention, a three-phase voltage and current root-mean-square value is dynamically calculated through a broadband current transformer and a sliding window integration method, a 50Hz fundamental component amplitude is extracted to separate power frequency and high frequency harmonic waves, a continuous period energy efficiency ratio standard deviation triggers an insulation detection threshold value, and a parameter fluctuation and insulation degradation response mechanism is established. Harmonic interference correction synchronous processing energy efficiency ratio and leakage current integration, the detection error being lower than 5%, temperature rise rate linear regression and bearing current threshold value cooperative determination, winding aging cross validation, fault misjudgment rate reduction to 26%, closed-loop detection fusion transient capture, dynamic threshold value triggering and multi-parameter diagnosis, early warning success rate reaching 92%, and positioning response being reduced to 3 seconds.

The invention relates to a PFC-PWM (Pulse Width Modulation) dual-mode control method for a high-voltage direct-current power supply with a wide output voltage range. The output current of the high-voltage direct-current power supply is detected in real time, the critical threshold value of the load impedance is mapped into the hysteresis interval of the output current, the theoretical boundary of mode switching is obtained, and the control mode is dynamically adjusted. In order to further guarantee smooth switching of the two control modes, hysteresis control logic is designed, and undisturbed smooth switching of the PFM mode and the PWM mode is achieved. Based on an energy equivalence principle and a frequency consistency constraint of a critical load SWL working point, a current threshold criterion and a parameter pre-synchronization strategy are constructed, seamless connection of a mode switching process in a frequency domain and an energy domain is ensured, a transient oscillation risk is remarkably reduced, and a guarantee is provided for continuous and stable output of a full-range load working condition.

A method protects against fault arcs in an electric power distribution system in which electric power from an electric feed point is distributed via a common superordinate main distribution line and from the common main distribution line via multiple subordinate output lines. The main distribution line can be interrupted by a main switch, and each of the output lines can be interrupted by a paired output switch. A fault arc current threshold which, when exceeded by a fault arc current of a fault arc, is a precondition for triggering the main switch is matched to the maximum forward current and / or the output trigger duration of the output switches such that a fault arc is quenched selectively either by one of the output switches or by the main switch before the energy released by the fault arc exceeds a specified energy threshold.

The invention discloses a phase jump fault recovery method and system for a network-building type inverter, and the method comprises the steps: giving a-q-axis current component of a current loop reference value of the network-building type inverter as an allowable maximum current value in response to a phase jump fault of a power grid and triggering a current amplitude limiting request of the network-building type inverter, forming an amplitude limiting current loop reference value and limiting the amplitude of the output current of the grid-forming inverter; after the current amplitude limiting is relieved, the active power of the grid-forming type inverter is updated, a current loop reference value of the grid-forming type inverter is updated through the updated active power, and the current loop reference value is the current loop reference value obtained after the current amplitude limiting of the amplitude limiting current loop reference value is relieved; and under the condition that the current loop reference value is smaller than a preset current threshold value, the power grid is switched into a grid construction control state, so that the transient stability of the system is enhanced, the system can return to the balance point autonomously, and the grid construction operation state is recovered.

The invention relates to the technical field of new energy automobile generator performance detection, and discloses an automobile generator performance detection method and device. The method comprises the steps of collecting working condition data such as voltage, current, rotating speed and internal temperature of a generator in real time through a multi-source sensor, establishing a correlation model among the voltage, the current, the rotating speed and the internal temperature based on a regression analysis method, and dynamically adjusting safety thresholds of the voltage and the current according to the model. Compared with the prior art that monitoring depends on a fixed threshold value, especially under complex working conditions such as high load, rapid acceleration and high temperature conditions, the technical problem that working condition changes cannot be adapted in real time is solved, real-time monitoring is achieved by dynamically adjusting the voltage and current threshold values and combining the rotating speed and the internal temperature change rate, and the real-time monitoring efficiency is improved. The stable operation of the generator under the multi-dimensional working condition is ensured, so that the problem of equipment damage caused by overload is avoided, the safety of the system is improved, and the service life of the system is prolonged.

The invention relates to the technical field of industrial control, in particular to a battery SOC balance control method, an inverter parallel operation system, equipment and a medium. The battery SOC equalization control method comprises the following steps: according to a preset equalization period, a current inverter obtains a battery actual SOC of a high-voltage battery connected with the current inverter, and provides the battery actual SOC for a preset host so as to obtain an average SOC provided by the preset host according to the battery actual SOC; obtaining an SOC difference value between the actual SOC and the average SOC of the battery, and obtaining a current correction value based on the SOC difference value; and obtaining the charging and discharging states of the inverter parallel operation system and the battery current threshold value of the high-voltage battery, and correcting the battery current threshold value by adopting the current correction value based on the charging and discharging states to obtain a final current threshold value. According to the invention, the balance of the SOC of the inverter parallel operation system is improved, the overhigh load of part of inverters is avoided, and the fault risk is reduced, so that the stability and reliability of the inverter parallel operation system are enhanced.

A circuit breaker protecting an electrical low-voltage circuit includes a mechanical separating contact operable by a mechanical handle switching a contact opening function preventing current flow or a closing function for current flow. An electronic interruption unit connected to the mechanical separating contact unit in series on the circuit side, as a result of semiconductor-based switch elements, is switchable to a high-ohmic state of the switch elements preventing current flow or a low-ohmic state thereof for current flow. An ascertained current level is compared with current thresholds and, if exceeded, initiates prevention of current flow in the circuit. When contacts are closed and the interruption unit is in the low-ohmic state, the interruption unit switches to the high-ohmic state upon initiating a voltage-reduced state of the circuit. After discontinuing the voltage-reduced state, the interruption unit switches back to the low-ohmic state.

The invention discloses a network construction type energy storage transient performance improving method and system, and the method comprises the steps: dividing a maximum current threshold value of an energy storage current converter in a transient state into a current under a dq coordinate system, calculating the total impedance required by current limiting through combining the component of the A-phase current output by the energy storage current converter on a d axis and the voltage difference between the two ends, setting the virtual impedance, and carrying out the current limiting through the virtual impedance. Virtual impedance is introduced into a current control link to realize over-current limitation; and the current control link outputs voltage, and the output voltage acts on the VSG power control link to realize power angle control. The system comprises a current control module and a power control module. According to the invention, through adaptive adjustment of the virtual impedance and correction of the active power instruction value, the overcurrent is effectively suppressed in the low voltage ride through process, and the power angle of the system is maintained to be stable, so that the transient performance of the network-forming type energy storage system is improved.

The invention discloses an operation control method of a low-power-consumption off-grid inverter, electronic equipment and a storage medium, and the operation control method comprises the steps: maintaining an output switch to be in a closed state when the output current of an AC output port is detected to be greater than or equal to a first preset current threshold value under the condition that the off-grid inverter is in a no-load low-power-consumption mode, the inverter side is controlled to close driving, and the driving duty ratio of the LLC low-voltage side is adjusted to be a first preset duty ratio, so that the voltage of the bus capacitor is increased to be a preset steady-state voltage; and when it is detected that the voltage of the bus capacitor reaches the preset steady-state voltage, the inverter side is controlled to start driving. According to the low-power-consumption off-grid inverter, the output switch is kept in the closed state, the inverter side is controlled to close driving, and the driving duty ratio of the LLC low-voltage side is correspondingly adjusted, so that the impact current input by the LLC low-voltage side is reduced, the capacitor voltage stress of the LLC high-voltage side and the stress of a power device of the low-voltage side are reduced, and the reliability of the low-power-consumption off-grid inverter can be remarkably improved.

The battery pack comprises a plurality of batteries, each battery comprises a shell, a cover plate, a pole, a conducting bar and a battery cell, and the shell is provided with an opening; the cover plate covers the opening, and a through hole is formed in the cover plate; the pole is arranged in the through hole; the conducting bar is electrically connected with one surface, deviating from the battery cell, of the pole; the battery cell comprises a battery cell main body and a tab, the battery cell main body is arranged in the shell, the tab comprises a first connecting part, a fusing part and a second connecting part, the sectional area of the first connecting part and the sectional area of the second connecting part are both larger than the sectional area of the fusing part, the first connecting part is connected with the battery cell main body, and the second connecting part is connected with the end, located in the shell, of the pole; the minimum sectional area of the fusing part is S1 mm, the surface area of the conducting bar is S2 mm, the thickness of the conducting bar is T1 mm, and S1 * S2 * T1 is larger than or equal to 9600 and smaller than or equal to 32,000. According to the invention, the fusing part can be fused under the originally set current threshold value, so that the safety of the battery pack is ensured.

The invention relates to a driving control circuit and a switching power supply, the driving control circuit comprises a current sampling circuit and a light-load wave sealing circuit, the current sampling circuit is electrically connected with the light-load wave sealing circuit, the current sampling circuit samples current flowing through a load to obtain sampling current, and when the sampling current is greater than a current threshold value, the light-load wave sealing circuit is electrically connected with the light-load wave sealing circuit; the light-load wave sealing circuit outputs a first control signal to enable the second group of switching tubes to work based on a received second driving signal, so that the switching power supply rapidly quits the light-load wave sealing state, the current-carrying capacity of the switching power supply is rapidly improved, and when the sampling current is smaller than or equal to a current threshold value, the switching power supply is switched off. And the light-load wave sealing circuit outputs a second control signal to drive the second group of switching tubes to stop working, so that the second group of switching tubes are ensured to be closed in a light-load state, the switching loss during light load is effectively reduced, and the light-load energy efficiency is improved.

The invention provides a current detection and circuit protection method and system for a chip, and relates to the technical field of chips, and the method comprises the steps: obtaining a current detection result of a target chip; comparing the current detection result with a preset current threshold value, if the target chip is over-current, adaptively determining a multi-gear protection grade corresponding to the comparison result according to the comparison result of the current detection result and the preset current threshold value, and determining a corresponding protection strategy based on the multi-gear protection grade; according to the protection strategy, an adjustable current limiting module in a power supply circuit of the target chip is controlled to gradually recover the power supply current of the target chip in stages, and whether the current detection result exceeds the preset current threshold value or not is judged when each recovery stage is ended; and if so, returning to the previous recovery stage to continue recovery until the power supply current of the target chip is recovered to the normal working state within the preset recovery time.

The embodiment of the invention provides a charging method and device, electronic equipment and a storage medium, and belongs to the technical field of lithium ion batteries, and the method comprises the steps: detecting whether a charging voltage value is smaller than a first preset threshold voltage value or not; if the charging voltage value is smaller than the first preset threshold voltage value, pre-charging the to-be-charged battery based on the first preset current until the charging voltage value reaches the first preset threshold voltage value, and controlling the to-be-charged battery to enter a constant-current charging stage; charging the to-be-charged battery based on a second preset current until the capacity value of the to-be-charged battery reaches a preset capacity threshold value, and entering a multi-stage constant-voltage charging stage; according to each charging voltage determined in the preset charging voltage range, performing stage charging on the to-be-charged battery until the charging voltage value reaches a second preset threshold voltage value, and controlling the to-be-charged battery to enter a final constant voltage charging stage; and when the charging current value is reduced to the charging current threshold value, charging is stopped. Through the provided scheme, the charging efficiency is improved, and the risk of battery damage is reduced.

The invention relates to the technical field of electric vehicle charging, in particular to a charging gun short-circuit fault detection method, and aims to solve the problems that in the prior art, charging gun short-circuit fault detection mainly depends on two technical paths of current threshold triggering and single parameter monitoring, when it is detected that the current exceeds a preset value, a circuit is cut off, detection hysteresis exists, and the detection time is shortened. And pre-judgment cannot be carried out before short circuit occurs, so that the equipment is damaged before the protection action is executed. According to the method, the digital twinning pre-diagnosis model is constructed by fusing multiple physical quantity data, early warning and graded protection of the short-circuit fault of the charging gun are realized by combining multi-dimensional feature fusion and a dynamic risk assessment mechanism, and the method has the advantages of improving the detection timeliness, reducing the misjudgment and missed judgment rate and enhancing the environmental adaptability.

The utility model relates to the technical field of battery energy, in particular to a battery cell and a battery. The battery cell comprises a battery cell body and at least three tab assemblies, the tab assembly is positioned at the end part of the battery cell body, comprises a plurality of tabs which are arranged in a stacked manner, and is provided with an overcurrent area; the size of the tab in the length direction of the pole piece is less than or equal to 45mm; the total area S of the overcurrent areas of all the tab assemblies meets the condition that S is greater than or equal to I / (K * F); wherein I is the maximum current threshold value allowed to pass through in the overcurrent region, K is the current-carrying capacity per unit area in the overcurrent region, and F is a correction coefficient; k is greater than or equal to 5A / mm < 2 > and less than or equal to 10A / mm < 2 >, I is greater than or equal to twice of the standard capacity of the battery, and the value range of F is 0.5-0.9. According to the battery cell provided by the invention, the tabs are not easy to fold, and after the battery cell is arranged in the battery, the over-current capability of the battery can be met, and the temperature rise of the battery in the charging and discharging process is reduced.

The invention discloses a vehicle-mounted ceiling screen anti-pinch method and device, electronic equipment and a storage medium, and relates to the technical field of vehicles. The method comprises the steps that under the condition that it is determined that the vehicle-mounted ceiling screen is in a starting state, the included angle between the current starting position of the vehicle-mounted ceiling screen and a vehicle roof and the current working current value of a motor used for driving the vehicle-mounted ceiling screen to be started are determined; when it is determined that the degree of the included angle is larger than a first set degree and the current working current value is larger than a first set current threshold value, anti-pinch control operation is conducted on the vehicle-mounted ceiling screen; wherein the first set current threshold value is determined based on a target working current value of the motor after the vehicle-mounted ceiling screen is started for a target set duration. The vehicle-mounted ceiling screen can be accurately and effectively prevented from clamping foreign matters in the starting process, the riding safety of passengers is ensured, and the riding experience of the passengers is improved.

The invention discloses a residual capacity balance control method and system for an aged lithium battery, and relates to the technical field of new energy materials and devices, and the method comprises the steps: inputting quantum magnetic field response data and infrasonic wave signals into a single-chip microcomputer, carrying out the wavelet noise reduction and histogram equalization processing based on an STM32 single-chip microcomputer, and generating an acoustic-magnetic coupling feature matrix; inputting a dynamic pheromone equalization model based on the acoustic-magnetic coupling characteristic matrix, calculating a capacity difference coupling coefficient between the battery packs through an ant colony optimization algorithm, and generating a capacity redistribution path topological graph; according to the capacity redistribution path topological graph, the energy transfer direction is controlled through a bidirectional Buck-Boost circuit, and an equalizing current threshold value is dynamically adjusted based on the quantum spin resonance magnetic field gradient; according to the invention, the quantum magnetic field response data of the aged lithium battery pack and the infrasonic wave signal generated by electrolyte decomposition are collected, so that the physical and chemical states in the battery are accurately monitored.

A DC-DC converter, an on-board charger, and an electric vehicle are disclosed. The DCDC converter includes: a first adjustment module, a resonance module, a second adjustment module, a current detection module, and a controller. The current detection module is configured to detect a current signal of the resonance module; and the controller is configured to control the first adjustment module and the second adjustment module to reduce an output power when the current signal is greater than a current threshold. By directly detecting the current signal of the resonance module, a high precision and a faster response are achieved.

The embodiment of the invention discloses a defrosting control method and device, an air conditioner and a computer readable storage medium, and relates to the technical field of air conditioners. The defrosting control method comprises the steps that the current of a draught fan is obtained; acquiring a plurality of current characteristics of the current; acquiring environment temperature and environment humidity; determining a dynamic current threshold according to the environment temperature and the environment humidity; based on the multiple current characteristics, the environment temperature, the environment humidity and the dynamic current threshold value, the frosting probability is determined; and when the frosting probability is larger than a frosting probability threshold value, defrosting control is carried out. Therefore, according to the scheme, whether frosting occurs or not can be accurately judged, and accurate defrosting control is achieved.

The invention discloses an intelligent circuit breaker state identification method and system based on an electric signal, and the method comprises the steps: detecting a current flowing through a circuit breaker in real time, and judging whether the current exceeds a preset overload current threshold value or not; when the current exceeds an overload current threshold value, detecting a real-time bending angle of the bimetallic strip at a preset frequency; monitoring the tripping state of the circuit breaker, and generating a circuit breaker fault alarm signal when the real-time bending angle exceeds a preset safety angle threshold value and the circuit breaker does not execute the tripping action. According to the invention, the current is monitored in real time, the bending angle of the bimetallic strip is detected during overload, and the alarm signal is generated during abnormity, so that the fault detection time is greatly shortened compared with the traditional mode, hidden dangers can be found at the early stage of overload, and the circuit is effectively prevented from being burnt out due to long overload time.

A short circuit identification method is provided for a sampling element of a battery management system. A temperature sensor is disposed in a battery management system to monitor a temperature of a discharge transistor, and the method includes: obtaining the temperature of the discharge transistor by using the temperature sensor, and calculating a temperature difference of the discharge transistor in a preset duration; comparing a discharge current obtained by using a sampling element with a preset current threshold; and determining that the sampling element is short-circuited. In embodiments of the present application, the temperature sensor is used to monitor the temperature change rate of the discharge transistor in the BMS system, it can be detected that only one sampling element has a short-circuit fault with reference to the discharge current obtained by the sampling element, and corresponding protection measures are taken, so that the BMS system runs safely and stably.

The invention provides a power conversion device and a control method thereof. The power conversion device comprises a direct current end, at least two power conversion bridge arms, a controller and an alternating current end. The direct-current end of the power conversion device is used for connecting a photovoltaic module or an energy storage battery, and the alternating-current end of the power conversion device is used for connecting a power grid or a load. And the at least two power conversion bridge arms are used for converting direct current output by the photovoltaic module or the energy storage battery into alternating current and outputting the alternating current to a power grid or a load. The controller is used for controlling the modulation wave of each power conversion bridge arm in the at least two power conversion bridge arms to be periodically and sequentially switched between at least two different discontinuous pulse width modulation waves under the condition that the current value of the alternating current end of the power conversion device is larger than a current threshold value. According to the invention, the loss of the bottleneck switch tube can be balanced, so that the loss of the bottleneck switch tube is effectively reduced.

A level conversion assembly (50), an overcurrent protection method and a display device, the level conversion assembly (50) comprising a level conversion module (51), the level conversion module (51) comprising a control unit (511), a current detection unit (512), a level conversion unit (513) and an overcurrent protection unit (514). When a control unit (511) is at a first falling edge of a digital clock signal (CPV), a first analog clock signal corresponding to the first falling edge in a plurality of analog clock signals (CLK1-CLK8) is determined based on the corresponding relation of the current display mode, and a current detection unit (512) is controlled to detect the current of the first analog clock signal. Since the moment of the falling edge of the digital clock signal (CPV) is located in the last row of the high level period or the low level period in the corresponding analog clock signal, the current detection unit (512) can send an overcurrent signal to the overcurrent protection unit (514) when the current of the first analog clock signal is not located in the current threshold range. The effect of improving the accuracy of over-current phenomenon detection is achieved.

The invention provides a self-adaptive PD charging control method and system based on a double Type-C circuit and a storage medium, and the method comprises the steps: monitoring an interface connection state in real time, collecting power-on current information when peripheral access is detected, and intelligently recognizing a device type in combination with a preset current threshold range and a PD protocol handshake process. The function change-over switch and the charging management module are dynamically configured; if the device is a data device, a data path is connected and power output is limited; if the device is a charging device, charging parameters are negotiated and high-power transmission is started; when the double charging devices are connected, intelligent power distribution and priority management are executed, electrical parameters such as voltage, current and temperature are continuously monitored, and self-adaptive adjustment is triggered when the voltage, the current, the temperature and the like exceed the limit. According to the invention, intelligent function switching and safe power management of double interfaces are realized, the risk of misplug damage is effectively avoided, and the equipment compatibility, the system energy efficiency and the user experience are improved.

The invention relates to the technical field of fault diagnosis, and particularly discloses a method and a system for checking a power fault position of a controller, and the method comprises the steps: collecting the state data of the controller at the current moment; constructing a fault fusion feature vector; judging a main cause branch of a power fault; and a standby branch is accessed by adopting a first-on-second-off mechanism, and a fault branch is cut off. In the prior art, a single voltage or current threshold value is mainly depended on determination, and especially under a dynamic operation condition that a controller has multi-path redundant power supply, rapid identification and switching of a specific fault path are difficult to realize. Due to the fact that the fault vector fusing the multi-source power features is constructed and the multi-factor weighted aggregation judgment mechanism is introduced, the accuracy of fault recognition and the stability of switching operation are improved, the problem of global power failure caused by fault diffusion is avoided, and the power supply continuity and the fault self-healing capacity of a motor controller system are improved.

The invention discloses a parallel operation control method and system of an energy storage converter. The method comprises the following steps: acquiring an output current of a load end of the energy storage converter, generating a state switching signal through the main energy storage converter according to a difference between the output current and a preset current threshold value, sending the state switching signal to the ith slave energy storage converter, and sending the state switching signal to the ith slave energy storage converter through the ith slave energy storage converter. And switching the operation mode of the ith slave energy storage converter or generating an ith state signal according to the state switching signal and the operation state of the ith slave energy storage converter, and sending a state switching signal to the (i + 1) th slave energy storage converter through the main energy storage converter according to the ith state signal. According to the invention, the number of the energy storage converters in the grid-connected / off-grid mode is automatically adjusted according to the change of the load capacity, the conversion efficiency and the adaptive capability of the energy storage converters are improved, and the system benefit is maximized while the load demand of a user side is met.

A multi-phase voltage regulator circuit applied in a multi-phase power converter is provided. The multi-phase voltage regulator circuit comprises multiple comparison circuits. The comparison circuits are coupled to a power output stage circuit and configured to generate multiple control signals The power output stage circuit generates multiple output currents according to the control signals. Each of the comparison circuits comprises a comparator and a correction conversion circuit. The comparator is configured to receive a compensation signal and a reference signal, and receive a correction signal through a first correction terminal and to adjust a duty cycle of a corresponding one of the control signals according to the correction signal. The correction conversion circuit is configured to generate a correction signal according to an error current. The error current represents a difference between a current threshold value and a corresponding output current for the corresponding phase.

A circuit breaker protects an electric low-voltage circuit and contains a mechanical separating contact unit, which has an open state of its contacts in order to prevent a current flow in the low-voltage circuit or a closed state of the contacts for a current flow in the low-voltage circuit, and an electronic interruption unit, which is connected in series to the mechanical separating contact unit on the circuit side and which, as a result of semiconductor-based switch elements, has a high-ohmic state of the switch elements in order to prevent a current flow or a low-ohmic state of the switch elements for a current flow in the low-voltage circuit. The level of the current of the low-voltage circuit is ascertained, and if at least one current threshold or a current / time threshold is exceeded, a process for preventing a current flow in the low-voltage circuit is initiated.