Short-circuit protection method for MOSFET power converters connected to DC power supply networks

Abstract

This invention relates to a method for controlling a power converter connected to a DC voltage network, the power converter including a rotating motor, the converter including parallel arms, each equipped with at least two MOSFETs, and a control circuit including a protection module configured to prevent the MOSFETs of the same arm from conducting simultaneously. The method includes: detecting (410) a short circuit on the network, then deactivating (420) the protection module, and controlling (430) the MOSFETs in an ideal diode mode, in which each MOSFET immediately conducts when the voltage across it is negative, thus causing the MOSFETs of the same arm to conduct simultaneously when the current flowing through the filter inductor is greater than the current supplied by the motor, and causing a synchronous rectification mode once the current decreases.

Description

Technical Field

[0001] The present invention relates to a voltage converter equipped with a MOSFET semiconductor and connected between a DC power supply network and a rotating motor (e.g., an electric or hybrid motor / generator), and more specifically, to a method for protecting a circuit equipped with such a converter from a short circuit. Existing technology

[0002] Figure 1 The conventional architecture of the power circuit of the rotating electric machine 1 is shown. This conventional architecture includes a motor / generator type rotating electric machine 1 and a semiconductor power converter 2 connected between the rotating electric machine 1 and the DC power grid 3. The semiconductors of the power converter 2 are MOSFET (metal-oxide-semiconductor field-effect transistors) 4, which are assembled into three electrical branches 5. These electrical branches 5 are assembled in parallel with each other, and each electrical branch 5 includes two MOSFETs 4 assembled in series. Each electrical branch 5 is coupled to one phase of the rotating electric machine 1.

[0003] The architecture also includes a filter capacitor 6 coupled in parallel to the electrical branch 5, and a filter inductor 7 coupled in series between the DC power grid 1 and the filter capacitor 6. A wiring resistor 8 is also shown in the figure.

[0004] In this standard architecture, power converter 2 forms a voltage inverter. The rotating motor 1 electrically coupled to converter 2 is a motor such as a PMSM (permanent magnet synchronous motor).

[0005] Power converter 2 is controlled by MOSFET gate control circuit 9. Under normal operation, MOSFET 4 of inverter 2 is controlled by pulse width modulation (PWM) control circuit to drive motor (propulsion mode) or obtain power (generator mode) to supply power to DC grid.

[0006] If a short circuit occurs in DC network 1 ( Figure 1 (The power supply of the DC network is schematically replaced with a wire). The filter capacitor 6 suddenly discharges to a short circuit through the filter inductor 7 and the inductance of the wire. This short circuit forms an oscillating circuit between the filter capacitor 6 and the very weakly damped inductor. The oscillating current from this oscillating circuit, which is much larger than the current of the converter 2, reverses the voltage across the filter capacitor 6, causing the body (reverse) diodes of the MOSFET to turn on, and these diodes then conduct to short circuit.

[0007] This short-circuit current could damage MOSFET 4 unless they are designed to have a larger capacity or an anti-parallel diode is added.

[0008] Several techniques exist to handle network short circuits and safely release filter capacitors.

[0009] US Patent Application US 2021 / 0080491 discloses a detection circuit for an active discharge circuit of a capacitor. This document describes a widely used practice of using an active discharge circuit by adding a dedicated circuit in parallel with the inverter. This dedicated circuit's function is to discharge the capacitor in a controlled and safe manner once a fault requiring discharge is detected. Therefore, the entire current is absorbed by this circuit, preventing any impact on other components of the power stage.

[0010] This active discharge solution enables the controlled discharge of the filter capacitor into a dedicated parallel circuit of the network.

[0011] On the other hand, it cannot prevent the filter capacitor from discharging to short circuits present on the network (the active discharge circuits are connected in parallel).

[0012] To protect the system from short circuits, it is also known to add parallel components, such as anti-parallel diodes or additional MOSFETs, to conduct short-circuit current.

[0013] Although this technology is the most commonly used, it leads to additional costs and an increase in the size of the power module.

[0014] US Patent US006021055 relates to a switching circuit with synchronous conduction that employs the latter technique to handle a specific load. The specific load requires a voltage higher than its nominal operating voltage to start, such as in the case of a discharge lamp. To apply a high voltage for a short period, the document proposes applying conduction in an ideal diode mode via the synchronous conduction mode of a MOSFET, with the aim of generating an overvoltage to light the lamp.

[0015] Even though this embodiment involves synchronously turning on the MOSFETs for a short period of time, it cannot solve the problem of reducing diode losses in the event of a network short circuit.

[0016] Therefore, in existing technologies, capacitor discharge management under fault conditions such as short circuits is typically based on adding an active discharge circuit or adding components (parallel diodes or additional MOSFETs). Both solutions suffer from high cost and large size due to the addition of new components or the increase in size of existing components to account for fault conditions. Summary of the Invention

[0017] The purpose of this invention is to provide a principle for controlling the MOSFET of an inverter, which can limit the loss of the MOSFET and the risk of damage due to self-heating when a short circuit occurs in the DC power supply network, while limiting additional cost and size.

[0018] In other words, the main objective of this invention is to reduce the thermal stress on the MOSFET of a power converter during a short circuit in the DC voltage network that causes the capacitor to discharge through the MOSFET.

[0019] In a first aspect of the invention, a method is provided for controlling a power converter in an electrical system connected to a DC voltage network to protect the electrical system from short circuits in the DC voltage network. The electrical system includes a rotating motor and a power converter electrically connected between the DC voltage network and the motor. The power converter includes electric arms assembled in parallel with each other, filter capacitors coupled in parallel to the electric arms, and filter inductors connected in series between the filter capacitors and the DC voltage network to which the electrical system is coupled. Each electric arm includes a series assembly of at least two MOSFET transistors, and the power converter further includes control circuitry for the MOSFET gates, the control circuitry including a protection module specifically configured to prevent simultaneous conduction of MOSFETs in the same electric arm.

[0020] According to the general features of the present invention, a control method for protecting an electrical system from a short circuit in a DC voltage network includes the following steps:

[0021] • Detect short circuits on the DC voltage network, and then

[0022] • Deactivate the protection module of the MOSFET gate control circuit to allow MOSFETs in the same arm to conduct simultaneously, and

[0023] • Activate MOSFET gate control in ideal diode mode, in which each MOSFET turns on immediately when the voltage across it is negative.

[0024] After the protection module of the MOSFET gate control circuit is deactivated, controlling the MOSFET gate in ideal diode mode will result in the following: as long as the current flowing through the filter inductor is greater than the current provided by the rotating motor, the MOSFETs of the same arm will be turned on simultaneously; once the current flowing through the filter inductor is less than the current provided by the rotating motor, the synchronous rectification mode of the MOSFETs of the same arm will be restored.

[0025] Preferably, the rotary motor is configured to operate in electric motor mode or generator mode.

[0026] MOSFETs are typically controlled by gate control circuitry or “gate drivers” or “drivers”. These circuits achieve the transmission of command signals from the controller to the gate, gate control, component protection (such as desaturation, power supply undervoltage, etc.), dead time, and interlocking functions through current isolation. The purpose of these functions is to prevent MOSFETs on the same arm from conducting simultaneously, because simultaneous conduction will cause the capacitors of the DC voltage network to short-circuit, and increase losses or even damage the components.

[0027] The method according to the invention enables switching to a so-called ideal diode control mode for the MOSFET upon detection of a short circuit in the DC voltage network. This control specifically enables the disabling of interlocking functions, thereby allowing operation in a synchronous conduction mode during the energy discharge phase of the DC voltage network capacitor.

[0028] Therefore, the control method includes a MOSFET synchronous turn-on phase that is typically prohibited for voltage converters.

[0029] like Figure 2 As shown in the characteristics of the voltage drop (drain-source voltage VDS) between the drain and source of a MOSFET, the reverse conduction of the MOSFET can limit losses.

[0030] Specifically, in this example, with the MOSFET controlled (Vgs=15V), the voltage drop in the on-state is approximately -1.5V for a current of -100A, while for the same current, if the MOSFET is not controlled (Vgs=0V), the voltage drop is approximately -4.5V, which reduces the loss to one-third of the original.

[0031] When the capacitor's energy is dissipated, this control allows for a natural return to synchronous rectification mode.

[0032] Furthermore, the method of using MOSFET synchronous conduction stages according to the present invention can significantly reduce the junction temperature of the MOSFET, thereby extending the MOSFET's lifespan. Tests show that for two strictly identical circuits but with different MOSFET control methods, the thermal stress of the MOSFET is significantly reduced (junction temperature reduced by 25 to 36°C).

[0033] Therefore, the method according to the invention provides a solution for protecting against short circuits in DC voltage networks without adding or increasing the size of power components. This is achieved by employing an ideal diode mode conduction under certain conditions.

[0034] Advantageously, the detection of a short circuit in a DC voltage network may include: detecting a voltage drop across the DC voltage network by periodically iteratively measuring the voltage across the DC voltage network and comparing the measured voltage with a voltage threshold; if the voltage drop is below the voltage threshold, the voltage drop corresponds to a short circuit in the DC voltage network.

[0035] In one variation, the detection of a short circuit in a DC voltage network may include: continuously measuring the current on the DC voltage network, and detecting a reversal of the current direction at the output of the DC voltage network based on the sign direction of the measured current during operation of the rotating machine in motor mode, and detecting an excess of a short-circuit current threshold based on a comparison of the measured current with a current threshold during operation of the electrical system in generator mode.

[0036] Advantageously, MOSFET gate control in the ideal diode mode can include: for each MOSFET, measuring the voltage between the drain and source of the MOSFET, comparing the measured voltage between the drain and source of the MOSFET with zero voltage, and turning on the MOSFET once the measured voltage between the drain and source of the MOSFET is negative.

[0037] In one variation, MOSFET gate control in the ideal diode mode can include: for each MOSFET, measuring the current flowing through the MOSFET (measured in the positive direction from the drain to the source of the MOSFET), comparing the measured current to a zero or slightly negative current threshold, and turning on the MOSFET once the current is less than the threshold.

[0038] In another aspect of the invention, an electrical system is provided intended for connection to a DC voltage network. This electrical system includes a rotating electric motor configured to operate in motor mode or generator mode, and a power converter connected between the rotating electric motor and a connection terminal intended for connection to the DC voltage network. The power converter includes electric arms assembled in parallel with each other, filter capacitors coupled in parallel to the electric arms, and filter inductors connected in series between the filter capacitors and one of the connection terminals. Each electric arm includes a series connection of at least two MOSFET transistors, and the power converter further includes control circuitry for the gates of the MOSFETs, the control circuitry including a protection module specifically configured to prevent the MOSFETs of the same electric arm from conducting simultaneously.

[0039] According to the general features of the electrical system of the present invention, in addition to an electrical protection device for preventing short circuits in the DC voltage network to which the electrical system is to be connected, the electrical protection device includes:

[0040] • A module used to detect short circuits on DC voltage networks.

[0041] A module for deactivating the protection module of the MOSFET gate control circuit controlled by the short-circuit detection module.

[0042] • At least one MOSFET gate control module is configured to control at least one MOSFET in an ideal diode mode, in which each MOSFET turns on immediately when the voltage across its terminals is negative.

[0043] After the protection module of the MOSFET gate control circuit is deactivated, controlling the MOSFET gate in ideal diode mode will result in the following: as long as the current flowing through the filter inductor is greater than the current provided by the rotating motor, the MOSFETs of the same arm will be turned on simultaneously; once the current flowing through the filter inductor is less than the current provided by the rotating motor, the synchronous rectification mode of the MOSFETs of the same arm will be restored.

[0044] Preferably, the rotary motor can be a permanent magnet motor, which is controlled by pulse width modulation under normal operation without short circuits to drive the motor or obtain power from a generator to supply power to the DC grid.

[0045] Advantageously, the MOSFET gate control circuit may include a control input and a reset input for use in normal operation without short circuits, the reset input being configured to deactivate a protection module of the gate control circuit upon receiving a deactivation signal.

[0046] Advantageously, the electrical system may include a first MOSFET gate control module for each MOSFET, the first control module including a multiplexer comprising: a first input configured to receive a normal operation command for the MOSFET; a second input configured to receive an operation command in ideal diode mode; a selection input; and an output configured to copy the first input as long as no signal is received at the selection input, and to copy the second input to the output of the multiplexer when a selection signal is received at the selection input, wherein the selection signal is received when the MOSFET gate control circuit receives a reset command at its reset input.

[0047] In one embodiment, the electrical protection device may further include: means for measuring the voltage across a DC voltage network coupled to a connection terminal, and means for comparing the measured voltage with a voltage threshold (below which a voltage drop corresponds to a short circuit on the DC voltage network); or means for measuring the current flowing through a DC voltage network coupled to one of the connection terminals, and means for comparing the measured current with a current threshold.

[0048] Brief description of the attached figures

[0049] The invention will be better understood by reading the following illustrative and not limiting description with reference to the accompanying drawings, in which:

[0050] already described Figure 1 A schematic diagram of the power circuit architecture of a rotary electric motor according to the prior art is shown.

[0051] As described Figure 2This is a graphical representation of the voltage between the drain and source of a MOSFET as a function of the current between the drain and source, and the voltage between the gate and source.

[0052] Figure 3 An electrical system according to an embodiment of the present invention is illustrated schematically.

[0053] Figure 4 An embodiment of the present invention is shown for protection Figure 3 A flowchart of the method for the electrical system.

[0054] Description of the Implementation Examples

[0055] Figure 3 A wiring diagram of an electrical system 10 according to an embodiment of the present invention is shown.

[0056] The electrical system includes a permanent magnet motor type rotary motor 11, a power converter 12 with connection terminals 13, and an electrical protection unit 14, wherein the connection terminals 13 are configured to be electrically connected to a DC voltage network 30, and the electrical protection unit 14 is used to protect the electrical system 10 from the effects of a short circuit in the DC voltage network 30.

[0057] The power converter 12 includes three arms 15 assembled in parallel with each other. Each arm 15 includes a series assembly of two MOSFETs 16 having the same conduction direction. Each arm 15 includes an electrical node 17 that is coupled to each MOSFET 16 of the arm 15 on one side and to one phase of the rotary motor 11 on the other.

[0058] The power converter 12 also includes a filter capacitor 18 assembled in parallel with the electric arm 15, and a filter inductor 19 coupled between the filter capacitor 18 and a connection terminal 13. Figure 3 The wiring resistor 20 is also shown.

[0059] Electrical system 1 also includes MOSFET gate control circuitry 40. MOSFET gate control circuitry 40 is configured to transmit control signals from the controller to the gate of each MOSFET via electrical isolation. Specifically, under normal operation (i.e., without any short circuits), it controls the MOSFETs 16 of the power converter 12 to send signals to the motor 11 and drive the motor via pulse width modulation, or to draw power from the generator to supply power to a DC voltage network.

[0060] The MOSFET gate control circuit 40 also includes a protection module 42 configured to manage dead time and interlocking, thereby preventing the simultaneous conduction of MOSFETs 16 in the same arm 15. This prevention typically avoids short circuits in the DC voltage network capacitors and prevents increased losses or even component damage.

[0061] The electrical protection unit 14 includes: a module 141 for detecting short circuits on the DC voltage network 30, a module 142 for deactivating a protection module 42 for the MOSFET gate control circuit 40, and a MOSFET gate control module 143.

[0062] After a short circuit is detected on the DC voltage network 30, the MOSFET gate control module 143 replaces the MOSFET gate control circuit 40.

[0063] The module 141 for detecting short circuits on the DC voltage network 30 includes means 145 for measuring the voltage across the connection terminal 13 and means 146 for comparing the measured voltage with a voltage threshold (below which a voltage drop corresponds to a short circuit on the DC voltage network 30).

[0064] In one variant, the module 141 for detecting short circuits on the DC voltage network 30 may include means for measuring the current flowing through the connection terminal 13 and means for comparing the measured current with a current threshold.

[0065] The MOSFET gate control circuit 40 may include a control input and a reset input for use in normal operation without any short circuits. The reset input is configured to deactivate the protection module 42 of the gate control circuit 40 upon receiving a deactivation signal sent by the deactivation module 142.

[0066] MOSFET gate control module 143 is configured to control each MOSFET 16 in an ideal diode mode, in which each MOSFET 16 immediately turns on when the voltage across its terminals is negative. Control module 143 is controlled in response to a signal from deactivation module 142. Controlling the MOSFET gate 16 in the ideal diode mode results in the following: as long as the current flowing through filter inductor 19 is greater than the current supplied by rotary motor 11, the MOSFETs 16 in the same arm 15 turn on simultaneously; once the current flowing through filter inductor 19 is less than the current supplied by rotary motor 11, the synchronous rectification mode of the MOSFETs 16 in the same arm 15 is restored.

[0067] Figure 4 A flowchart is shown of a method for controlling a power converter 12 of an electrical system 10 to protect the electrical system 10 from short circuits in a DC voltage network 30 to which the electrical system 10 is to be connected, according to one embodiment of the present invention.

[0068] The control method according to an embodiment of the present invention includes step 410 of detecting a short circuit on a DC voltage network 30.

[0069] The step of detecting a short circuit on the DC voltage network 30 includes detecting the voltage drop across the DC voltage network. The voltage drop is detected by monitoring the voltage across the DC voltage network 30. This monitoring is achieved by periodically measuring the voltage at connection terminal 12 and comparing each voltage measurement with a voltage threshold (below which a voltage drop corresponds to a short circuit on the DC voltage network).

[0070] In one variant, detecting a short circuit on the DC voltage network 30 includes: continuously measuring the current at the connection terminal 13; and during operation of the rotating motor in motor mode, detecting a reversal of the current direction at the output of the DC voltage network based on the signal of the measured current; and during operation of the electrical system in generator mode, detecting an excess of a short-circuit current threshold based on a comparison of the measured current with a current threshold.

[0071] The method then includes a step 420 of deactivating the protection module 42 of the MOSFET gate control circuit 40. This deactivation removes the prohibition of simultaneous conduction of MOSFETs 16 in the same arm 15. Therefore, the control method includes a MOSFETs 16 synchronous conduction phase that is normally prohibited for voltage converters.

[0072] Simultaneously with step 420, the method includes step 430 of activating MOSFET gate control in an ideal diode mode, in which each MOSFET 16 is immediately turned on when the voltage across it is negative.

[0073] Step 430 of activating MOSFET gate control in ideal diode mode includes: for each MOSFET 16, measuring the voltage between the drain and source of the MOSFET 16, comparing the measured drain-source voltage of the MOSFET 16 with zero voltage, and turning on the MOSFET 16 once the measured drain-source voltage of the MOSFET is negative.

[0074] Therefore, controlling the gate of MOSFET 16 in ideal diode mode will result in the MOSFETs 16 of the same arm 15 being turned on simultaneously as long as the current flowing through the filter inductor (step 440) is greater than the current supplied by the rotary motor 11.

[0075] Once the filter inductor 19 has completely discharged, in step 440, operation in ideal diode mode automatically causes the synchronous rectification mode of the MOSFET 16 in the same arm 15 to be restored (step 450). In other words, synchronous rectification is restored once the current flowing through the filter inductor is less than the current supplied by the rotary motor 11.

[0076] Subsequently, once the short-circuit fault is dealt with (by disconnecting the circuit through a fuse, circuit breaker, contact switch, etc.), the voltage will rise again, and once the voltage exceeds a threshold greater than the aforementioned voltage threshold, normal control of the converter is allowed to be restarted.

[0077] In a variant not shown, the electrical system 10 may include a plurality of first MOSFET gate control modules. More specifically, it may include a first MOSFET gate control module for each MOSFET. In this configuration, each first control module includes a multiplexer comprising: a first input configured to receive a normal operation command for the MOSFET; a second input configured to receive an operation command in ideal diode mode; a selection input; and an output configured to copy the first input as long as no signal is received at the selection input, and to copy the second input to the output of the multiplexer when a selection signal is received at the selection input, wherein the selection signal is received when the MOSFET gate control circuit receives a reset command at its reset input.

[0078] Therefore, the present invention provides a technical solution that enables control of the inverter's MOSFETs to limit losses and the risk of damage due to self-heating when a short circuit occurs in the DC voltage network, while limiting additional financial costs and size.

Claims

1. A method for controlling a power converter (12) of an electrical system (10) connected to a DC voltage network (30) to protect the electrical system (10) from short circuits in the DC voltage network (30), the electrical system (10) including a rotary motor (11) and a power converter (12) electrically connected between the DC voltage network (30) and the rotary motor (11), the power converter (12) including electric arms (15) assembled in parallel with each other and filters coupled in parallel to the electric arms (15). The power converter (12) includes a capacitor (18) and a filter inductor (19) connected in series between the filter capacitor (18) and the DC voltage network (30) to which the electrical system (10) is coupled. Each arm (15) includes a series assembly of at least two MOSFET transistors (16), and the power converter (12) further includes a control circuit (40) for the gates of the MOSFETs. The control circuit (40) includes a protection module (42) configured to prevent the MOSFETs (16) of the same arm (15) from being turned on simultaneously. The control method for protecting the electrical system (10) from short circuits in the DC voltage network (30) includes the following steps: -Detect (410) a short circuit on the DC voltage network (30), then - Deactivate (420) the protection module (42) of the control circuit (40) of the gate of the MOSFETs (16) so that the MOSFETs (16) of the same arm (15) are simultaneously turned on, and -Activate (430) MOSFET gate (16) control in ideal diode mode, in which each MOSFET (16) turns on immediately when the voltage across its terminals is negative.

2. The method according to claim 1, wherein, The detection (410) of a short circuit on the DC voltage network (30) includes: detecting the voltage drop across the DC voltage network (30) by periodically iterating the voltage measurement values ​​across the DC voltage network (30) and comparing the voltage measurement values ​​with a voltage threshold. If the voltage drop is lower than the voltage threshold, the voltage drop corresponds to a short circuit on the DC voltage network (30).

3. The method according to claim 1, wherein, The detection (410) of a short circuit on the DC voltage network (30) includes: continuously measuring the current on the DC voltage network (30), and during operation of the rotating motor (11) in motor mode, detecting a reversal of the current direction at the output of the DC voltage network (30) based on the signal direction of the measured current, and during operation of the electrical system (10) in generator mode, detecting a short circuit current threshold based on a comparison of the measured current with a current threshold.

4. The method according to any one of claims 1 to 3, wherein, The gate control of the MOSFET (16) in the ideal diode mode of activation (430) includes: for each MOSFET (16), measuring the voltage between the drain and source of the MOSFET (16), comparing the measured voltage between the drain and source of the MOSFET (16) with zero voltage, and turning on the MOSFET (16) once the measured voltage between the drain and source of the MOSFET (16) is negative.

5. The method according to any one of claims 1 to 3, wherein, Activating (430) the gate control of the MOSFET (16) in the ideal diode mode includes: for each MOSFET (16), measuring the current flowing through the MOSFET in the positive direction from the drain to the source of the MOSFET; comparing the measured current with a zero or slightly negative current threshold, and turning on the MOSFET (16) once the current is less than the threshold.

6. An electrical system (10) intended for connection to a DC voltage network (30), the electrical system (10) comprising a rotary motor (11) and a power converter (12) connected between the rotary motor (11) and a connection terminal (13) intended for connection to the DC voltage network (30), the power converter (12) comprising electric arms (15) assembled in parallel with each other, a filter capacitor (18) coupled in parallel to the electric arms (15), and a filter inductor (19) connected in series between the filter capacitor (18) and one of the connection terminals (13), each electric arm (15) comprising a series assembly of at least two MOSFET transistors (16), and the power converter (12) further comprising control circuitry (40) for the gates of the MOSFETs, the control circuitry (40) comprising a protection module (42) configured to prevent the MOSFETs (16) of the same electric arm (15) from being turned on simultaneously, characterized in that, It also includes an electrical protection device (14) for preventing the effects of a short circuit (30) to which the electrical system (10) is to be connected, the electrical protection device (14) comprising: - A module (141) for detecting short circuits on the DC voltage network (30). - A module (142) for deactivating the protection module (42) of the control circuit (40) of the MOSFET gate controlled by the short-circuit detection module (141). - At least one MOSFET gate control module (143) is configured to control at least one MOSFET (16) in an ideal diode mode, in which the MOSFET (16) is turned on immediately when the voltage across its terminals is negative.

7. The electrical system (10) according to claim 6, wherein, The rotary motor (11) is a permanent magnet motor that is controlled by pulse width modulation under normal operation without short circuits to drive the motor or obtain power from the generator to supply power to the DC grid (30).

8. The electrical system (10) according to claim 6 or 7, wherein the MOSFET gate control circuit (40) includes a control input and a reset input for use in normal operation without short circuit, the reset input being configured to deactivate the protection module (42) of the gate control circuit (40) upon receiving a deactivation signal.

9. The electrical system (10) of claim 8, comprising a first MOSFET gate control module for each MOSFET, the first control module comprising a multiplexer, the multiplexer comprising: The first input is configured to receive normal operation commands from the MOSFET; The second input is configured to receive operating commands in ideal diode mode; Select input; The output is configured to copy the first input as long as no signal is received at the selected input, and to copy the second input to the output of the multiplexer when the selected input receives a selected signal, and to receive the selected signal when the control circuit of the MOSFET gate receives a reset command at its reset input.

10. The electrical system (10) according to any one of claims 6 to 9, wherein, The electrical protection device (14) further includes: means (145) for measuring the voltage across the DC voltage network coupled to the connection terminal, and means (146) for comparing the measured voltage with a voltage threshold, wherein a voltage drop below the voltage threshold corresponds to a short circuit on the DC voltage network; or means for measuring the current flowing through the DC voltage network coupled to one of the connection terminals, and means for comparing the measured current with a current threshold.

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