319 results about "Circuit switching" patented technology

The invention relates to an optical data network (10-1) for connecting a plurality of data network nodes (N1-1, N2-1, N3-1, N4-1). The optical data network (10-1) comprises: i) the plurality of data network nodes (N1-1, N2-1, N3-1, N4-1), the data (99) comprising data packets (99p), wherein each data network node (N1-1, N2-1, N3-1, N4-1) is provided with a network interface (Nl); and ii) a data connection network (100-1) comprising at least one data switch (SW) and a plurality of optical connections (50) for allowing establishment of data links (DL1, DL2) between pairs of said plurality of data network nodes (N1-1, N2-1, N3-1, N4-1). At least one of the at least one data switch (SW) is a smart data switch (SSW) comprising at least one packet switch (PS, EPS) and at least one circuit switch (CS, OCS), At least two network interfaces are smart network interfaces (SN, SNC) comprising a data classifier (25) configured for classifying the data packets (99p) into at least two traffic classes including first traffic class (D1) and a second traffic class (D2) in accordance with a classification scheme. The smart data switch (SSW) and the network interfaces (SN, SNC) are configured to route the data packets (99p) of the first traffic class (D1) to the packet switch (PS, EPS) and to route the data packets (99p) of the second traffic class (D2) to the circuit switch (CS, OCS).

The invention discloses a remote ignition control system for a release flare, and relates to the technical field of release flare control, the system comprises the following components: a fault detection module, a fault isolation module, a standby module, a redundant circuit switching module, a fault diagnosis module and a wireless communication module; by integrating multiple modules of fault detection, fault isolation, standby module and redundant circuit switching, fault diagnosis and wireless communication, comprehensive remote monitoring and management of the release flare ignition control system are achieved, when the system detects a fault, electrical connection of a fault component can be rapidly cut off, and the safety of the release flare ignition control system is improved. And the standby module or the redundant circuit is automatically switched, so that the continuous and stable operation of the system is ensured, the reliability and the safety of the system are remarkably improved, and the risk of production interruption caused by faults is reduced.

The invention relates to the technical field of charge and discharge detection, and discloses a multichannel EIS charge and discharge in-situ test system and method, and the system comprises a DC charge and discharge module which is used for carrying out the constant-current, constant-voltage or cyclic charge and discharge test of a battery; the alternating current impedance test module is connected in parallel with the direct current charging and discharging module and is used for applying an alternating current disturbance signal to the battery and collecting impedance response in the charging and discharging process; and the unified clock module is used for providing a synchronous triggering reference signal for the direct current charging and discharging module and the alternating current impedance test module. The direct current charging and discharging module and the alternating current impedance test module are designed to be of a parallel connection normally-connected structure, no relay switching is needed, continuous and uninterrupted online EIS test in the charging and discharging process is achieved, contact resistance drift and transient errors caused by physical circuit switching in a traditional scheme are effectively avoided, and the reliability of the EIS test is improved. And the stability and repeatability of the test are obviously improved.

The invention discloses a double-voltage adaptive rectification PFC (Power Factor Correction) circuit structure and an electric flame stove. The double-voltage adaptive rectification PFC circuit structure comprises an EMI (Electro-Magnetic Interference) filtering unit, a voltage doubling rectification unit, a full-bridge rectification unit, a circuit switching control unit, a startup protection unit and a power factor correction unit. According to the circuit switching control unit, through conversion of full-bridge rectification or voltage-multiplying rectification, adaptability to commercial power of two different voltages is achieved; according to the power-on protection unit, when 220V mains supply is input, after the circuit voltage is stabilized, the relay RLY2 is completely switched on, and soft start protection is achieved; according to the invention, the MOS tube Q1 / Q2 is alternately connected and disconnected in a time sequence, so that the inductor L2 stores energy or discharges, the capacitor C22 is charged or discharged, the power factor correction unit outputs stable high-voltage electricity to a rear-end circuit or a load, when the MOS tube Q2 is connected, the resistance is zero, the superposed high-voltage electricity is transmitted to the rear-end circuit when the potential of the inductor L2 discharges, and low-loss energy conversion is realized.

The invention belongs to the technical field of power management, and particularly relates to an ultrasonic mode control circuit for limiting the lower limit of light load switching frequency. According to the invention, an ultrasonic mode control circuit is designed, and the ultrasonic mode control circuit is nested in the switching converter as an independent circuit and can monitor the switching period. When the switching period is close to the audio frequency range, the DCM state is forcibly quitted, and the flip point of the ZCD is adjusted through the loop to enable the inductive current to flow backward, so that the circuit balance is realized. According to the invention, the problem of noise interference of the current switching power supply converter in an extremely light load state is solved from the source. As the system load is gradually reduced, the circuit switching frequency is gradually reduced so as to improve the conversion efficiency. When the switching frequency is reduced to a designed lower limit threshold, the frequency is stable and does not continue to be reduced. The system has the advantages of a current mainstream control mode for improving light load efficiency, and solves the problem of noise during extremely light load.

An adaptive control method for a fault control-oriented economically-integrated medium-voltage grid-connected device with a silicon carbide (SiC) module, includes: calculating a three-phase bridge arm modulation wave and a fourth bridge arm modulation wave; obtaining a three-phase bridge arm neutral point clamped (NPC) circuit switching signal; obtaining a three-phase bridge arm NPC circuit output voltage; obtaining a fourth bridge arm NPC circuit switching signal; obtaining a fourth bridge arm NPC circuit output voltage; calculating a voltage-stabilizing active vector of each submodule of a cascaded H-bridge (CHB) circuit; obtaining a three-phase bridge arm CHB circuit switching signal; obtaining a fourth bridge arm CHB circuit switching signal based on the fourth bridge arm modulation wave, the fourth bridge arm NPC circuit output voltage, and the voltage-stabilizing active vector of each submodule of the CHB circuit; and performing adaptive control of a grid-connected device based on the CHB circuit switching signal.

The invention discloses a self-adaptive cutting method and cutting teeth for a mining heading machine, and relates to the technical field of coal mine underground coal or rock roadway heading operation. The adaptive cutting method comprises the following steps: constructing a hardness identification source domain model, taking cutting current, voltage, arm vibration and torque signals of a laboratory as source domain signals, extracting features through a multi-layer convolutional neural network, fusing the features with a minimum absolute operator, and training; training in a laboratory by using a back propagation algorithm until the precision reaches the standard; migrating to a tunneling site, performing fine adjustment and updating on site signal input as a target domain model, and outputting hardness of a cutting object; the working modes of the cutting tooth are controlled according to hardness, the cutting tooth comprises a cutting tooth seat, an impact spring, a piston and the like, and an oil way is controlled to switch the working modes through a hydraulic control one-way valve and an electromagnetic reversing valve. The cutting mode can be automatically adjusted according to the coal rock hardness, and compared with a traditional fixed parameter cutting mode, the cutting efficiency can be greatly improved, cutting tooth abrasion is reduced, and energy consumption is reduced.

The control valve for cleaning the base station comprises a first valve section and a third valve section, the first valve section comprises a first shell and a first valve element rotationally installed in the first shell, a liquid inlet, a first liquid outlet and a second liquid outlet are formed in the first shell, a first channel is formed in the first valve element, and a second channel is formed in the second valve element; when the first valve element moves, any one of the first liquid outlet and the second liquid outlet is switched to be communicated with the liquid inlet through the first channel; the third valve section comprises a third shell and a third valve element rotationally installed in the third shell, the third shell is provided with a cleaning liquid outlet and a plurality of cleaning liquid inlets, a third channel is formed in the third valve element, and when the third valve element rotates, any one of the cleaning liquid inlets is switched to be communicated with the cleaning liquid outlet through the third channel. According to the invention, the technical problem that the switching control of the cleaning water loop and the adding control of the cleaning liquid cannot be realized through the same control valve in the cleaning base station can be improved.

A switching power supply circuit includes: a switching circuit switching an input voltage; a first amplifier generating a first voltage; a first phase compensation circuit including a first capacitor and compensating for a phase of the first voltage; a second amplifier generating a second voltage; a second phase compensation circuit including a second capacitor and compensating for a phase of the second voltage; and a drive control circuit executing a switching operation according to the second voltage, wherein the switching power supply circuit operates in a first or second mode, the drive control circuit performs, in the first mode, the switching operation, and stops, in the second mode, the switching operation, and when returning from the second mode to the first mode, a specific voltage corresponding to an output voltage is supplied to the second capacitor and a predetermined voltage is supplied to the first capacitor.

A wireless power transfer device includes: a power transmitting resonant circuit including a power transmitting coil and a power transmitting capacitor; a switching circuit switching a state of the power transmitting resonant circuit between a resonant state and a non-resonant state; and a determination circuit determining whether a facing state in which the power transmitting coil faces the power receiving coil or a non-facing state in which the power transmitting coil does not face the power receiving coil is occurring. After determining that either one of the non-facing state and the facing state transitions to the other one, the switching circuit performs switching process to switch from either one of the non-resonant state and the resonant state to the other one within a voltage zero-crossing range including a voltage zero-crossing point and a current zero-crossing range including a current zero-crossing point of the power transmitting coil or power transmitting capacitor.

The invention discloses a voltage monitoring device and a monitoring method thereof, and relates to the technical field of voltage monitors, the voltage monitoring device comprises a monitor main body, a main monitoring module and an auxiliary monitoring module are arranged in the monitor main body, a loop switching mechanism and a locking mechanism are arranged in the monitor main body, and a wiring chamber is arranged on the upper end face of the monitor main body. A main loop terminal, an auxiliary loop terminal and a to-be-tested line terminal are arranged in the wiring chamber, a detachable wiring cover is arranged at the upper end of the wiring chamber, and the loop switching mechanism comprises a rotating shaft seat, a switching deflector rod, a push plate, a sliding energy storage box, a fixed base, a first motor and a lead screw. The loop switching mechanism is installed between the main loop terminal and the auxiliary loop terminal and used for circuit switching. The voltage monitoring device has the advantages of dual-module cooperative work, rapid automatic switching and intelligent fault diagnosis, and solves the problems that a traditional voltage monitoring device is inaccurate in data and difficult in fault positioning in a severe environment.

The invention relates to an electrical performance test system, in particular to an electromagnetic valve electrical performance test system. The equipment main control unit comprises a main control computer, and a display and a communication bus module which are connected with the main control computer; the communication bus module comprises an RS232 interface module and a network communication interface module; the test unit comprises a coil resistance test unit, an electrical parameter test unit and a plurality of voltage and current detection units which are connected with the network communication interface module, and a test circuit switching module which is connected with the RS232 interface module and the equipment main control unit; the coil resistance test unit and the electrical parameter test unit are connected with the test circuit switching module. And the voltage and current detection unit and the test circuit switching module are connected with the plurality of electromagnetic valves. Compared with the existing test equipment, different test equipment does not need to be replaced according to different test items, so that the test efficiency is improved, and the labor intensity of workers is reduced.

An electric circuit switching device includes a housing; an igniter configured to release a combustion gas upon actuation; a tubular space formed in the housing; a projectile having conductivity, including a base body positioned at a first position in the tubular space in an initial state, and configured to be projected in a predetermined projecting direction by energy of the combustion gas; and a pair of first conductor pieces provided inserted, in a spaced apart state, into the tubular space at a position closer to the projecting direction side than the first position. The projectile further includes a pair of protrusions protruding from the base body in the projecting direction. The pair of protrusions of the projectile projected upon actuation of the igniter respectively come into contact with the pair of first conductor pieces, switching the first electric circuit from an interrupted state to a conductive state.

The invention discloses an intelligent energy scheduling method for an energy storage and charging direct-current coupling system, and the method employs a bidirectional buck-boost intelligent switching control module, a duty ratio optimization algorithm module, an intelligent control circuit switching module, a mode switching judgment algorithm module, a safety interlocking protection module, and a parameter interaction fusion mechanism. The method is used for realizing collaborative optimization control among algorithm modules, and comprises the following steps: transmitting voltage stability monitoring parameters from a bidirectional buck-boost intelligent switching control module to a duty ratio optimization algorithm module; the duty ratio change rate and the control stability parameter are transmitted to the safety interlocking protection module and the mode switching judgment algorithm module from the duty ratio optimization algorithm module, and the safety state information is transmitted to the intelligent control circuit switching module from the safety interlocking protection module. According to the invention, flexible, efficient and safe charging of the electric vehicles on different voltage platforms by the energy storage battery is realized, the real-time performance, the accuracy and the reliability of the system are considered, and collaborative optimization control is realized through a parameter interaction mechanism.

The invention relates to the technical field of low-voltage switch cabinets, and particularly discloses a drawer type low-voltage switch cabinet which comprises supporting legs, a drawer frame is fixedly connected to the tops of the supporting legs, an electric control assembly is arranged on the inner side of the drawer frame, and a switch assembly is installed on the front face of the electric control assembly. The back surface of the inner side of the drawer frame is fixedly connected with a connecting switch; in the process of needing circuit switching, a user firstly pushes the electric control main body, then drives the rotary transmission rod and the rotary positioning shaft to rotate by rotating the rotary handle, and then drives the positioning sensing assembly, the first buffer assembly, the second buffer assembly and the contact switch assembly to rotate; when the touch control positioning groove is opened, the contact plate rotates from one side of the touch control positioning groove to the other side, so that a circuit is switched from one side to the other side, and when the contact plate is far away from the other side, the circuit on the other side is disconnected, so that the two circuits cannot be opened at the same time, and a user can operate conveniently.

The application relates to a dual-power switching switch which comprises a shell, a coil driving module and a main circuit switching module; the main circuit switching module comprises a handle switching and retaining mechanism, a handle and a guide assembly; the handle can rotate relative to the main support under the action of external force to make the two guide assemblies rotate in the mounting space of the main support, the two ends of the guide assembly act on the main support and the handle respectively, so that the handle is kept in the switched state; the elastic retaining mechanism comprises a shifting piece, a tension spring and a sliding block; the sliding block is slidingly arranged on the base; the handle rotates under the action of external force to drive the shifting piece to rotate and drive the sliding block to move, so that the tension spring is deviated to one side where the moving contact and the load static contact are in contact, the tension spring acts on the shifting piece to apply pressure on the contact; the arc extinguishing chambers are arranged on the two sides of a group of rotating assemblies. The handle switching and retaining mechanism and the elastic retaining mechanism ensure that the contact pressure between the poles of the main circuit is consistent.

This application relates to a distribution cabinet for an integrated busbar system in the field of power equipment. It includes a cabinet, a busbar support, a busbar copper busbar assembly, a current-carrying copper busbar assembly, a load switch, and an incoming switch. The busbar support includes a mounting base disposed within the cabinet, with multiple mounting slots on the mounting base. The busbar copper busbar assembly includes a live wire busbar and a neutral wire busbar, with the mounting slots for mounting either the live wire busbar or the neutral wire busbar respectively. The current-carrying copper busbar assembly includes a live wire current-carrying copper busbar and a neutral wire current-carrying copper busbar, both mounted on the busbar support. The live wire current-carrying copper busbar is electrically connected to the live wire busbar, and the neutral wire current-carrying copper busbar is electrically connected to the neutral wire busbar. The load switch controls the circuit switching of the electrical equipment. The incoming switch controls the switching of the main power supply to the distribution cabinet. This application improves the adaptability of the distribution box in different power usage scenarios.

Generally disclosed herein is an approach for optimizing routing strategy to tolerate faults in a toroidal network topology including, but not limited to, N-dimensional mesh, torus, and twisted torus. The approach may include balancing a load for a specified input traffic pattern operating offline or online. The approach may also include an optimization enhancement technique specifically applicable to symmetric, dynamically composable toroidal networks based on a set of centrally connected circuit switches.

The utility model relates to electronic equipment technical field discloses a kind of radio frequency circuit and electronic equipment, radio frequency circuit includes: cellular communication antenna;First GPS antenna;Second GPS antenna, compared with first GPS antenna, with higher spatial isolation between the cellular communication antenna;Radio frequency switching circuit, the input of the radio frequency switching circuit is connected the first GPS antenna and second GPS antenna, the output of the radio frequency switching circuit is connected GPS demodulator;Control module is connected with cellular communication module, for according to the interference state of cellular communication module output, control the radio frequency switching circuit switching and the connection state of the first GPS antenna and second GPS antenna. By the interference state of cellular communication module output dynamic adjustment antenna path, to enhance overall anti-interference capability. It is favorable to provide more stable GPS receiving path in the scene where cellular interference exists.

The utility model relates to a power supply system for being synchronously opened or closed with an electric appliance. The power supply system comprises a power supply circuit; the relay is arranged on the power supply circuit; the control module is electrically connected with the relay; the power supply module is electrically connected with the control module; the wireless trigger circuit comprises a data coding unit, a trigger switch and a radio transmission unit which are connected in series; the radio receiving unit is used for receiving the radio signal transmitted by the radio transmitting unit; the trigger switch is a flexible switch, is adhered to the electric appliance switch and is used for synchronously acting with the electric appliance switch, and the control module controls the on-off of the relay based on a radio signal received by the radio receiving unit. According to the application, the flexible trigger switch is adhered to the electric appliance switch, and the trigger switch is utilized to control the on-off of the wireless trigger circuit so as to transmit the corresponding electric signal, so that the control module controls the on-off of the relay based on the electric signal so as to achieve the purpose of controlling the on-off of the power supply circuit, thereby realizing the synchronous power-on or power-off of the power supply circuit and the electric appliance.

To achieve a scalable call environment at low cost without increasing the complexity or size of a device.SOLUTION: A line exchange switches lines between a first terminal, which is an input-side terminal, and a second terminal, which is an output-side terminal. The line exchange includes: a first interface unit that is an input-side interface for connecting to the first terminal, the first interface unit packetizing voice data received from the first terminal in predetermined units and outputting the packetized packet data; a packet switch unit that routes the packet data output from the first interface unit; and a second interface unit that is an output-side interface for connecting to the second terminal, the second interface unit having a clock matching unit that writes the routed packet data to a data buffer and reads out the written packet data at a read timing indicated by a time margin value determined based on delay and / or fluctuation of the packet switch unit.SELECTED DRAWING: Figure 1

This invention relates to the field of temperature protector technology, and more particularly to an adjustable temperature protector structure and its usage method. The structure includes: an outer base with a locking interface; a switching outer shell rotatably connected to the outer base; a first limiting groove, a second limiting groove, and a transition groove within the switching outer shell; an inner base mounted on the locking interface; a first conductor fixed to the inner base; a slider sliding on the first conductor; a limiting protrusion on the side of the slider; an inclined surface on the side of the slider facing the inner base; a second conductor fixed to the inner base; a moving contact piece attached to and fixed to the inner base; and a deformation piece disposed between the first conductor and the moving contact piece. When the slider is closest to the inner base, the inclined surface aligns with the center of the deformation piece; when the slider is furthest from the inner base, the inclined surface aligns with the side of the deformation piece furthest from the inner base. This invention enables free adjustment of the temperature protector's operating mode, improves circuit switching efficiency, and avoids circuit damage.

The utility model belongs to the field of Internet of Things, and relates to a core board conforming to Jetson Orin Nano, which comprises an Internet of Things chip, a Jetson Orin Nano chip and a Jetson Orin Nano chip, the PCIE bridging controller chip, the power supply management chip, the power supply management system chip, the USB Hub controller, the Ethernet physical layer chip, the direct current power supply input circuit, the PMIC clock circuit, the analog power supply electromagnetic interference protection circuit, the LPDDR4 power supply circuit, the automatic power-on circuit, the PCIE switching circuit, the PCIE expansion chip power supply circuit and the PMIC interface circuit are electrically connected with the Internet of Things chip; the USB Hub controller is further connected with the switch chip, and the Internet of Things chip is used for collecting, processing, transmitting and controlling data of Internet of Things equipment. Due to the fact that the data processing capacity is high, the expansibility is high, power management and data transmission are stable, and powerful technical support is provided for application of the Internet of Things.

The invention discloses a double-negative one-state single-phase common-ground five-level inverter topology which comprises a photovoltaic cell PV, a double-negative one-state single-phase five-level inverter circuit, a single-phase output LC filter circuit and a single-phase load. The double-negative-one-state single-phase five-level inverter circuit comprises a direct-current side input filter capacitor Cdc, flying capacitors C1 and C2 and ten switching tubes S1 to S10, S2, S4, S5 and S9 are IGBTs (Insulated Gate Bipolar Translator) with fly-wheel diodes, and other switching tubes are IGBTs without fly-wheel diodes. According to the invention, complete suppression of the leakage current of the inverter can be realized; the amplitude of the AC-side output SPWM voltage is twice of the DC-side voltage, so that the utilization rate of the DC-side voltage is remarkably improved; the charge and discharge balance of the capacitor voltage is realized through the selection of the negative state, so that the waveform quality of the output voltage is improved; in each working mode, the number of switching tubes connected in series in a current conduction loop is small, and the loss of circuit switching devices is low.

The device comprises a shell, a machine base is arranged in the shell, an end cover is installed at the position of an opening of the shell, a connecting circuit board is arranged on the machine base, a direct insertion type electric connector is installed on the end cover, and a circuit switching assembly is arranged between the direct insertion type electric connector and the connecting circuit board. The direct insertion type electric connector is directly inserted into the switching circuit board; the switching circuit board and the connecting circuit board are connected through the flexible electric connecting belt, circuit communication is achieved, wire bundle welding is replaced, the bending radius of a reserved wire bundle does not need to be considered, disordered crossing of wires does not exist, the miniaturization design of the structure is facilitated, and the assembly efficiency is improved.

The invention belongs to the technical field of high-frequency switching power supplies, and discloses a synchronous rectification high-frequency switching power supply, which comprises a shell used for accommodating power supply internal components; the air switch handle is used for controlling on-off of the power supply circuit; the power line inlet hole, the control line inlet hole and the communication line inlet hole are respectively used for accessing a power line, a control line and a communication line; the cathode and the anode are used for power output connection; the wire outlet copper bar is used for circuit switching; a water pressure gauge; through a temperature sensing adjusting mechanism, the heat dissipation system can respond to power supply load changes in real time, the through-flow area of a water inlet is automatically reduced during high load, the flow speed is increased through the Venturi tube effect, and the heat exchange efficiency is enhanced; and when the load is low, the flow rate is reduced, excessive heat dissipation is avoided, the dynamic adaptation capability ensures that the power supply can maintain a proper temperature under different working conditions, an overheat fault caused by insufficient heat dissipation is completely eradicated, and the operation stability in a severe environment is remarkably improved.

The utility model relates to the technical field of light control, specifically relates to a multi -mode light -adjusting controller, it contains power mechanism, power mechanism output direct current's VH and 3V3, set up MCU and the drive chip connected with it in the controller, drive chip controls relay ware one and relay ware two respectively, MCU still has the light coupling ware for realizing switching and synchronous step -down converter, and the synchronous step -down converter output is connected to relay ware two, and the normally open mouth of relay ware two is connected back end for connecting the positive pole of lamp VOUT, this application can automatically identify the load type of access, for example LED or incandescent lamp etc, and then can switch the drive mode, need not according to different type to select different controller, this application adopts relay ware and carries out circuit switching, avoids the mutual interference between different power components.

The invention discloses a power switch module, the power switch module comprises a substrate and a bridge arm, the bridge arm is arranged on the substrate, the bridge arm comprises an insulated gate bipolar transistor and a field effect transistor, and the insulated gate bipolar transistor and the field effect transistor are connected in parallel; wherein the insulated gate bipolar transistor is made of a silicon-based material, and the field effect transistor is made of a silicon carbide material. The Si IGBT serves as a main power switch module device, the output capacity of the power module is guaranteed, the SiC MOSFET serves as an auxiliary of the Si IGBT, and energy loss in the circuit on-off process is reduced. Through the main-auxiliary synergistic effect of the Si IGBTs and the SiC MOSFETs, the overall power density and the working efficiency of the power switch module can be improved, the stability of a system can be ensured, the production cost and the occupied space of the power switch module can be reduced under the condition that the power requirement is met, and the requirements for miniaturization and light weight of the power switch module are met.

Systems and methods for enhanced CSFB in a mobile operator core network are described. In one embodiment, a method of wireless communication by a user equipment (UE) is disclosed, comprising: directing a UE to move from an original cell using a first radio access technology (RAT) to a second cell using a second RAT to permit a circuit switched (CS) call; terminating the CS call at the second cell; determining whether the UE should reselect to the first RAT; identifying a target cell that may be in a same location as the second cell and that uses the first RAT; and sending the identified target cell to the UE within a field in a radio resource control message.

The invention relates to a method for operating a 3-level inverter (1), comprising an intermediate circuit (2) with three terminals (DC+, DC-, N) and three switching sections (3a, 3b, 3c), each with a phase tap (u, v, w) for electrically connecting to a respective phase (Phu, Phv, Phw) of an electric drive machine, wherein each switching section (3a, 3b, 3c) has three switching devices (S1, S2, S3), wherein - for modulating an operating point-specific output voltage, a control device determines a switching pattern by means of which the switching devices (S1, S2, S3) are transferred to different switching states and thereby connect the phase tap (Phu, Phv, Phw) of the respective switching section (3a, 3b, 3c) to one of the terminals (DC+, DC-, N) of the intermediate circuit (2) while generating a voltage vector, - during the modulation of the output voltage, curves (Iphu, Iphv, Iphw) of at least one characteristic of the electric drive unit are measured by a sensor device, for example on the basis of current and / or voltage measurements of the electrical phases (Phu, Phv, Phw), - the control device compares the measured curves (Iphu, Iphv, Iphw) with predetermined, switching pattern-specific error profiles, which each characterize a faulty short-circuited switching state of one of the switching devices (S1, S2, S3), based on the comparison a faulty short-circuited switching device (S1) of a switching section (3a) is identified and a switching pattern-specific, safe state is predicted by identifying the two switching devices (S1, S2) of the other switching sections (3b, 3c) which are to be closed to provide an active short circuit and which are connected to the same terminal (DC+) of the intermediate circuit (2) as the faulty switching device (S1).