Short-circuit protection method for a mosfet power converter connected to a DC power supply network

Abstract

The invention relates to a method for controlling a power converter connected to a DC voltage network and comprising a rotary electric machine, the converter comprising parallel electrical arms, each provided with at least two MOSFETs, and a control circuit comprising a protection module configured to prevent the simultaneous conduction of the MOSFETs in the same arm. The method comprises: - detecting (410) a short circuit in the network; then - deactivating (420) the protection module; and - controlling (430) the MOSFETs in an ideal diode mode, wherein each MOSFET conducts as soon as the voltage at its terminals is negative, thereby causing simultaneous conduction of the MOSFETs in the same arm when the current flowing through the filter inductor exceeds the current supplied by the electric machine, and in a synchronous rectification mode once the current is lower.

Description

[0001] Description

[0002] Title of the invention: Short-circuit protection method for a MOSFET power converter connected to a DC power supply network

[0003] Technical Field

[0004] The invention relates to voltage converters equipped with MOSFET semiconductors and connected between a direct voltage power supply network and a rotating machine such as an electric or hybrid electric motor / generator, and more particularly to a method of protecting against short circuits of an electrical circuit equipped with such a converter.

[0005] Prior art

[0006] Figure 1 shows a conventional architecture of a power circuit of a rotating machine 1. The conventional architecture comprises a rotating machine 1 of the motor / generator type and a semiconductor power converter 2 connected between the rotating machine 1 and a direct current (DC) electrical network 3. The semiconductors of the power converter 2 are insulated gate field effect transistors 4, more commonly called MOSFETs (acronym for "metal-oxide-semiconductor field-effect transistor"), assembled to form three electrical branches 5 connected in parallel with each other and each comprising two MOSFETs 4 connected in series. Each electrical branch 5 is coupled to a phase of the rotating machine 1.

[0007] The architecture further comprises a filter capacitor 6 coupled in parallel with the electrical branches 5, and a filter inductor 7 coupled in series between the DC electrical network 1 and the filter capacitor 6. A wiring resistor 8 has also been shown.

[0008] In this typical architecture, the power converter 2 forms a voltage inverter. The rotating machine 1 to which the converter 2 is electrically coupled is an electrical machine such as a permanent magnet synchronous machine, or PMSM.

[0009] The power converter 2 is controlled by a MOSFET gate control circuit 9. In normal operation, the MOSFETs 4 of the inverter 2 are controlled by the pulse width modulation (PWM) control circuit to drive the motor (propulsion mode) or to draw power (generator mode) to supply the DC power grid.

[0010] In the event of a short circuit on the DC network 1 (the power source of the DC network in Figure 1 is schematically replaced by a cable), the filter capacitor 6 suddenly discharges into the short circuit through the inductances of the filter inductor 7 and that of the cables. This short circuit forms an oscillating circuit between the filter capacitor 6 and the very weakly damped inductances. The oscillating current, coming from this oscillating circuit and much higher than the current of the converter 2, reverses the voltage across the filter capacitor 6, which has the consequence of turning on the intrinsic (reverse) diodes of the MOSFETs which then conduct the short circuit.

[0011] This short-circuit current can cause the MOSFET 4 to break, unless they are oversized or diodes are added in anti-parallel.

[0012] There are several techniques for reacting to a network short circuit and safely discharging the filter capacitor.

[0013] Document US 2021 / 0080491 discloses a detection circuit for an active discharge circuit of a capacitor. This document describes a widespread practice which consists of using an active discharge circuit by adding a dedicated circuit in parallel with the inverter whose role is to discharge the capacitor in a controlled and safe manner as soon as a fault requiring it is detected. Thus all the current is absorbed by this circuit avoiding any impact on the other components of the power stage.

[0014] This active discharge solution allows to control the discharge of the filter capacitor in a dedicated circuit in parallel with the network.

[0015] On the other hand, it does not prevent the filter capacitor from discharging in a short circuit present on the network (the active discharge circuit is in parallel).

[0016] To protect systems from short circuits, it is also known to add parallel components, such as antiparallel diodes or additional MOSFETs, to conduct the short-circuit current. Although this technique is the most widely used, it results in additional cost and an increase in the size of the power module.

[0017] Document US006021055, relating to a conversion circuit with synchronous conduction, uses this latter technique with particular loads. The particular loads used require a higher terminal voltage than in nominal operation in order to be able to start, as is the case with discharge lamps. In order to apply a high voltage for a short time, it is proposed in this document to apply conduction in ideal diode mode via a synchronous conduction mode of the MOSFETs, with the aim of creating an overvoltage in order to light a lamp.

[0018] This embodiment, even if it involves synchronous conduction of the MOSFETs for a short time, does not make it possible to address the problem of reducing losses in the diodes in the event of a short circuit on the network.

[0019] Thus, in the state of the art, the management of the discharge of capacities during faults such as short circuits is generally based either on the addition of an active discharge circuit or on the addition of components (diodes or additional MOSFETs in parallel). These two solutions are expensive (in volume and cost) either because of the addition of new components or by the oversizing of existing components in order to handle a malfunctioning case.

[0020] Statement of the invention

[0021] The invention aims to provide a principle for controlling the MOSFETs of the inverter making it possible to limit losses, and the risk of destruction by self-heating, of the MOSFETs in the event of a short circuit on the DC power supply network, while limiting the additional financial cost and size.

[0022] In other words, the main aim of the invention is to reduce the thermal stress of the MOSFETs of the power converter during a short circuit on the DC voltage network leading to the discharge of the capacitors through the MOSFETs.

[0023] In a first object of the invention, a method is proposed for controlling a power converter of an electrical system connected to a direct voltage network to protect the electrical system against a short circuit of the direct voltage network.The electrical system comprising a rotating electrical machine and a power converter electrically connected between the DC voltage network and the electrical machine, the power converter comprising electrical arms mounted in parallel with each other, a filtering capacitor coupled in parallel with the electrical arms and a filtering inductance connected in series between the filtering capacitor and said DC voltage network to which the electrical system is coupled, each electrical arm comprising a series connection of at least two insulated gate field effect transistors, MOSFETs, and the power converter further comprising a control circuit for the gates of the MOSFETs comprising a protection module configured in particular to prohibit the simultaneous conduction of the MOSFETs of the same arm.

[0024] According to a general characteristic of the invention, the control method for protecting the electrical system against a short circuit of the direct voltage network comprises the following steps:

[0025] - detection of a short circuit on the direct voltage network, then

[0026] - deactivation of the protection module of the MOSFET gate control circuit to allow simultaneous conduction of the MOSFETs of the same arm, and

[0027] - activation of a MOSFET gate control in an ideal diode mode in which each MOSFET conducts as soon as the voltage across its terminals is negative.

[0028] Driving the MOSFET gates in an ideal diode mode after deactivation of the protection module of the MOSFET gate drive circuit results in simultaneous conduction of the MOSFETs of the same arm as long as the current through the filter inductor is greater than the current delivered by the rotating electrical machine, and a resumption of a synchronous rectification mode of the MOSFETs of the same arm once the current through the filter inductor is less than the current delivered by the rotating electrical machine.

[0029] Preferably, the rotating electrical machine is configured to operate in motor mode or generator mode.

[0030] MOSFETs are conventionally controlled by gate driver circuits, or "gate drivers" or "drivers" in English, which provide the functions of transmitting control signals to the gate through galvanic isolation, gate control, component protection (desaturation, supply undervoltage, etc.) dead time and coupling, or "interlock" in English, which aim to prevent the simultaneous conduction of the MOSFETs of the same arm, which would cause the short-circuit of the capacitor of the DC voltage network and increase losses or even destroy the components.

[0031] The method according to the invention makes it possible to switch to a MOSFET control mode called ideal diode following the detection of a short circuit on the DC voltage network. This control makes it possible in particular to inhibit the coupling function ("interlock"), and thus to authorize operation in a synchronous conduction mode during the energy discharge phase of the capacitors of the DC voltage network.

[0032] The control process thus includes a synchronous conduction phase of the MOSFETs, which is usually prohibited for voltage converters.

[0033] The reverse conduction of MOSFETs makes it possible to limit losses as shown by the characteristics of the voltage drop between the drain and the source of the MOSFETs (Drain-Source Voltage V D s) in Figure 2.

[0034] Indeed, in this example, with MOSFET control (Vgs=15V), the voltage drop in the on state is of the order of -1.5V for a current of -100A, whereas it is of the order of -4.5V for this same current if the MOSFET is not controlled (Vgs=0V), which makes it possible to divide the losses by 3.

[0035] This command allows you to naturally return to synchronous rectification mode when the capacitor energy is dissipated.

[0036] Furthermore, the method according to the invention using a synchronous conduction phase of the MOSFETs makes it possible to obtain a significant reduction in the junction temperature of the MOSFETs and therefore an increase in the lifetime of the MOSFETs. Tests have shown that the thermal stress of the MOSFETs is significantly reduced (25 to 36 °C gained at the junction for two strictly identical circuits but with different MOSFET control).

[0037] The method according to the invention thus offers a solution for protecting against a short circuit in the DC voltage network without having to add or oversize power components. This is achieved by using ideal diode mode conduction under certain conditions.

[0038] Advantageously, the detection of a short circuit on the DC voltage network may comprise a detection of a voltage drop at the terminals of the DC voltage network via regular iterations of a measurement of the voltage at the terminals of the DC voltage network and a comparison of the measured voltage with a voltage threshold below which the voltage drop corresponds to a short circuit on the DC voltage network.

[0039] In a variant, the detection of a short circuit on the direct voltage network may comprise a continuous measurement of the current on the direct voltage network, and, during operation of the rotating electrical machine in motor mode, a detection of a reversal of the direction of current at the output of the direct voltage network from a detection of the sign of the measured current, and, during operation of the electrical system in generator mode, a detection of an exceeding of a short-circuit current threshold from a comparison of the measured current with a current threshold.

[0040] Advantageously, activating a control of the MOSFET gates in an ideal diode mode may comprise, for each MOSFET, a measurement of the voltage between the drain and the source of the MOSFET, a comparison of the voltage measured between the drain and the source of the MOSFET to a zero voltage, and a conduction of the MOSFET as soon as the voltage measured between the drain and the source of the MOSFET is negative.

[0041] In a variant, the activation of a control of the MOSFET gates in an ideal diode mode may comprise, for each MOSFET, a measurement of the current flowing through the MOSFET with a positive direction of measurement going from the drain to the source of the MOSFET, a comparison of the measured current to a zero or slightly negative current threshold, and a conduction of the MOSFET as soon as the current is below this threshold.

[0042] In another object of the invention, there is provided an electrical system intended to be connected to a DC voltage network, the electrical system comprising a rotating electrical machine configured to operate in motor mode or in generator mode and a power converter connected between the rotating electrical machine and connection terminals intended to be connected to the DC voltage network, the power converter comprising electrical arms mounted in parallel with each other, a filtering capacitor coupled in parallel with the electrical arms and a filtering inductance connected in series between the filtering capacitor and one of said connection terminals, each electrical arm comprising a series connection of at least two insulated gate field effect transistors, MOSFETs,and the power converter further comprising a MOSFET gate control circuit comprising a protection module configured in particular to prevent the simultaneous conduction of the MOSFETs of the same arm.

[0043] According to a general characteristic of the electrical system according to the invention, in addition to means of electrical protection against a short circuit of the direct voltage network to which the electrical system is intended to be connected, the means of electrical protection comprising:

[0044] - a module for detecting a short circuit on the direct voltage network,

[0045] - a module for deactivating the protection module of the MOSFET gate control circuit controlled by said short-circuit detection module,

[0046] - at least one MOSFET gate control module configured to control at least one MOSFET in an ideal diode mode in which each MOSFET conducts as soon as the voltage across its terminals is negative.

[0047] Driving the MOSFET gates in an ideal diode mode after deactivation of the protection module of the MOSFET gate drive circuit results in simultaneous conduction of the MOSFETs of the same arm as long as the current through the filter inductor is greater than the current delivered by the rotating electrical machine, and a resumption of a synchronous rectification mode of the MOSFETs of the same arm once the current through the filter inductor is less than the current delivered by the rotating electrical machine.

[0048] Preferably, said rotating electrical machine may be a permanent magnet machine controlled in normal operation, without short circuit, by pulse width modulation to drive the motor or take power from the generator to supply the DC electrical network. Advantageously, the gate control circuit of the MOSFETs may comprise a control input used in normal operation, without short circuit, and a reset input, the reset input being configured to deactivate the protection module of the gate control circuit upon receipt of a deactivation signal.

[0049] Advantageously, the electrical system may comprise a first MOSFET gate control module for each MOSFET, said first control module comprising a multiplexer comprising a first input configured to receive a normal operation command from the MOSFET, a second input configured to receive an ideal diode mode operation command, a selection input, and an output configured to copy the first input as long as no signal has been received on the selection input and to copy the second input to the output of the multiplexer when the selection input receives a selection signal, the selection signal being received when the MOSFET gate control circuit receives a reset command on its reset input.

[0050] In one embodiment, the electrical protection means may further comprise means for measuring the voltage at the terminals of the direct voltage network coupled to the connection terminals and means for comparing the measured voltage to a voltage threshold below which the voltage drop corresponds to a short circuit on the direct voltage network, or means for measuring the current flowing on the direct voltage network coupled to one of said connection terminals and means for comparing the measured current to a current threshold.

[0051] Brief description of the drawings

[0052] The invention will be better understood from the reading below, for informational but non-limiting purposes, with reference to the appended drawings in which:

[0053] [Fig. 1] Figure 1, already described, represents a schematic representation of an architecture of a power circuit of a rotating machine according to the state of the art. [Fig. 2] Figure 2, already described, is a graphical representation of the evolution of the voltage between the drain and the source of a MOSFET as a function of the current between the drain and the source and the voltage between the gate and the source.

[0054] [Fig. 3] Figure 3 schematically represents an electrical system according to one embodiment of the invention.

[0055] [Fig. 4] Figure 4 shows a flowchart of a method for protecting the electrical system of Figure 3 according to an embodiment of the invention.

[0056] Description of the embodiments

[0057] Figure 3 shows an electrical diagram of an electrical system 10 according to one embodiment of the invention.

[0058] The electrical system comprises a rotating electrical machine 11 of the permanent magnet machine type, a power converter 12 provided with connection terminals 13 configured to be electrically connected to a direct voltage network 30, and an electrical protection block 14 of the electrical system 10 against a short circuit of the direct voltage network 30.

[0059] The power converter 12 comprises three electrical arms 15 mounted in parallel with each other. Each electrical arm 15 comprises a series connection of two MOSFETs 16 having the same conduction direction. Each electrical arm 15 comprises an electrical node 17 coupled, on the one hand, to each of the MOSFETs 16 of the electrical arm 15, and on the other hand to a phase of the rotating electrical machine 11.

[0060] The power converter 12 further comprises a filter capacitor 18 connected in parallel with the electrical arms 15, as well as a filter inductance 19 coupled between the filter capacitor 18 and a connection terminal 13. In FIG. 3 a wiring resistor 20 has also been shown.

[0061] The electrical system 1 further comprises a control circuit 40 for the gates of the MOSFETs. The control circuit 40 for the gates of the MOSFETs is configured to transmit control command signals to the gate of each MOSFET through galvanic isolation. In particular, in normal operation, i.e. in the absence of a short circuit, it controls the MOSFETs 16 of the power converter 12 to send signals to the electrical machine 11 and control it using pulse width modulation to drive the motor or draw power from the generator to supply the DC electrical network.

[0062] The control circuit 40 of the MOSFET gates further comprises a protection module 42 which is configured to manage the dead times and the arm couplings, called “interlock” in English, and thus prohibit the simultaneous conduction of the MOSFETs 16 of the same arm 15. This prohibition generally makes it possible to avoid the formation of a short circuit of the capacitor of the DC voltage network and the increase in losses or even the destruction of the components.

[0063] The electrical protection block 14 comprises a module 141 for detecting a short circuit on the direct voltage network 30, a module 142 for deactivating the protection module 42 of the control circuit 40 of the MOSFET gates, and a MOSFET gate control module 143.

[0064] The MOSFET gate driver module 143 replaces the MOSFET gate driver circuit 40 following detection of a short circuit on the DC voltage network 30.

[0065] The module 141 for detecting a short circuit on the direct voltage network 30 comprises means 145 for measuring the voltage at the connection terminals 13 and means 146 for comparing the voltage measured to a voltage threshold below which the voltage drop corresponds to a short circuit on the direct voltage network 30.

[0066] In a variant, the module 141 for detecting a short circuit on the direct voltage network 30 may comprise means for measuring the current flowing on the connection terminals 13 and means for comparing the measured current to a current threshold.

[0067] The MOSFET gate driver circuit 40 may include a control input used in normal, non-short circuit operation and a reset input, the reset input being configured to disable the protection module 42 of the gate driver circuit 40 upon receipt of a disable signal from the disable module 142.

[0068] The MOSFET gate control module 143 is configured to control each of the MOSFETs 16 in an ideal diode mode in which each MOSFET 16 conducts as soon as the voltage across its terminals is negative. The control module 143 is controlled in response to the signal from the deactivation module 142. Controlling the MOSFET gates 16 in an ideal diode mode results in simultaneous conduction of the MOSFETs 16 of the same arm 15 as long as the current flowing through the filter inductor 19 is greater than the current delivered by the rotating electrical machine 11, and a resumption of a synchronous rectification mode of the MOSFETs 16 of the same arm 15 once the current flowing through the filter inductor 19 is less than the current delivered by the rotating electrical machine 11.

[0069] In Figure 4 is presented a logic diagram of a method for controlling the power converter 12 of the electrical system 10 to protect the electrical system 10 against a short circuit of the direct voltage network 30 to which the electrical system 10 is intended to be connected, according to an embodiment of the invention.

[0070] The control method according to the embodiment of the invention comprises a step 410 of detecting a short circuit on the direct voltage network 30.

[0071] The step of detecting a short circuit on the DC voltage network 30 comprises detecting a voltage drop across the terminals of the DC voltage network. The voltage drop is detected by monitoring the voltage across the terminals of the DC voltage network 30. The monitoring is carried out via regular measurements of the voltage on the connection terminals 13, and a comparison of each voltage measurement with a voltage threshold below which the voltage drop corresponds to a short circuit on the DC voltage network.

[0072] In a variant, the detection of a short circuit on the DC voltage network 30 comprises a continuous measurement of the current on a connection terminal 13, and, during operation of the rotating electrical machine in motor mode, a detection of a reversal of the direction of current at the output of the DC voltage network from a detection of the sign of the measured current, and, during operation of the electrical system in generator mode, a detection of an exceeding of a short-circuit current threshold from a comparison of the measured current with a current threshold. The method then comprises a step 420 of deactivating the protection module 42 of the control circuit 40 of the gates of the MOSFETs. This deactivation removes the prohibition of simultaneous conduction of the MOSFETs 16 of the same arm 15. Thus, the control method thus includes a synchronous conduction phase of the MOSFETs 16, usually prohibited for voltage converters.

[0073] At the same time as step 420, the method comprises a step 430 of activating a control of the MOSFET gates in an ideal diode mode in which each MOSFET 16 conducts as soon as the voltage across its terminals is negative.

[0074] Step 430 of activating a control of the MOSFET gates in an ideal diode mode comprises, for each MOSFET 16, a measurement of the voltage between the drain and the source of the MOSFET 16, a comparison of the voltage measured between the drain and the source of the MOSFET 16 to a zero voltage, and a conduction of the MOSFET 16 as soon as the voltage measured between the drain and the source of the MOSFET is negative.

[0075] Controlling the MOSFET gates 16 in an ideal diode mode thus causes simultaneous conduction of the MOSFETs 16 of the same arm 15 as long as the current flowing through the filtering inductance (step 440) is greater than the current delivered by the rotating electrical machine 11.

[0076] Once the filtering inductance 19 has discharged, in step 440, operation in ideal diode mode automatically causes a resumption of a synchronous rectification mode (step 450) of the MOSFETs 16 of the same arm 15. In other words, once the current passing through the filtering inductance is lower than the current delivered by the rotating electrical machine 11, synchronous rectification resumes.

[0077] Subsequently, once the fault that caused the short circuit has been dealt with (opening of the circuit by a fuse, a circuit breaker, a contactor, etc.), the voltage rises again and allows normal control of the converter to restart as soon as the voltage exceeds a threshold higher than the previous voltage threshold.

[0078] In a non-illustrated variant, the electrical system 10 may comprise a plurality of first MOSFET gate control modules. More particularly, it may comprise a first MOSFET gate control module for each MOSFET. In this configuration, each first control module comprises a multiplexer comprising a first input configured to receive a normal operation command from the MOSFET, a second input configured to receive an ideal diode mode operation command, a selection input, and an output configured to copy the first input as long as no signal has been received on the selection input and to copy the second input as an output of the multiplexer when the selection input receives a selection signal, the selection signal being received when the MOSFET gate control circuit receives a reset command on its reset input.

[0079] The invention thus provides a technical solution for controlling MOSFETs of an inverter to limit losses, and the risk of destruction by self-heating of the MOSFETs when a short circuit on the DC power supply network occurs, while limiting the additional financial cost and space requirement.

Claims

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) against a short circuit of the DC voltage network (30), the electrical system (10) comprising a rotating electrical machine (11) and a power converter (12) electrically connected between the DC voltage network (30) and the rotating electrical machine (11), the power converter (12) comprising electrical arms (15) connected in parallel to each other, a filter capacitor (18) coupled in parallel to the electrical arms (15) and a filter inductance (19) connected in series between the filter capacitor (18) and said DC voltage network (30) to which the electrical system (10) is coupled, each electrical arm (15) comprising a series connection of at least two insulated gate field effect transistors, MOSFETs, (16),and the power converter (12) further comprising a control circuit (40) for the gates of the MOSFETs comprising a protection module (42) configured to prohibit the simultaneous conduction of the MOSFETs (16) of the same arm (15), characterized in that the control method for protecting the electrical system (10) against a short circuit of the direct voltage network (30) comprises the following steps:, - detection (410) of a short circuit on the direct voltage network (30), then - a deactivation (420) of the protection module (42) of the control circuit (40) of the gates of the MOSFETs (16) to authorize the simultaneous conduction of the MOSFETs (16) of the same arm (15), and - an activation (430) of a control of the MOSFET gates (16) in an ideal diode mode in which each MOSFET (16) conducts as soon as the voltage at its terminals is negative.

2. The method of claim 1, wherein detecting (410) a short circuit on the DC voltage network (30) comprises detecting a voltage drop across the DC voltage network (30) via regular iterations of measuring the voltage across the DC voltage network (30) and comparing the measured voltage to a voltage threshold below which the voltage drop corresponds to a short circuit on the DC voltage network (30).

3. Method according to claim 1, in which the detection (410) of a short circuit on the direct voltage network (30) comprises a continuous measurement of the current on the direct voltage network (30), and, during operation of the rotating electrical machine (11) in motor mode, a detection of a reversal of the direction of current at the output of the direct voltage network (30) from a detection of the sign of the measured current, and, during operation of the electrical system (10) in generator mode, a detection of an exceeding of a short-circuit current threshold from a comparison of the measured current with a current threshold.

4. Method according to one of claims 1 to 3, in which the activation (430) of a control of the MOSFET gates (16) in an ideal diode mode comprises, for each MOSFET (16), a measurement of the voltage between the drain and the source of the MOSFET (16), a comparison of the voltage measured between the drain and the source of the MOSFET (16) to a zero voltage, and a conduction of the MOSFET (16) as soon as the voltage measured between the drain and the source of the MOSFET (16) is negative.

5. Method according to one of claims 1 to 3, in which the activation (430) of a control of the MOSFET gates (16) in an ideal diode mode comprises, for each MOSFET (16), a measurement of the current flowing through the MOSFET with a positive direction of the measurement going from the drain of the MOSFET towards the source, a comparison of the measured current to a zero or slightly negative current threshold, and a conduction of the MOSFET (16) as soon as the current is lower than this threshold.

6. Electrical system (10) intended to be connected to a direct voltage network (30), the electrical system (10) comprising a rotating electrical machine (11) and a power converter (12) connected between the rotating electrical machine (11) and connection terminals (13) intended to be connected to the direct voltage network (30), the power converter (12) comprising electrical arms (15) mounted in parallel with each other, a filtering capacitor (18) coupled in parallel with the electrical arms (15) and a filtering inductance (19) connected in series between the filtering capacitor (18) and one of said connection terminals (13), each electrical arm (15) comprising a series connection of at least two insulated gate field effect transistors, MOSFETs (16), and the power converter (12) further comprising a control circuit (40) for the gates of the MOSFETs comprising a protection module (42) configured to prohibit the simultaneous conduction of the MOSFETs (16) of the same arm (15),characterized in that it further comprises electrical protection means (14) against a short circuit of the direct voltage network (30) to which the electrical system (10) is intended to be connected, the electrical protection means (14) comprising:, - a module (141) for detecting a short circuit on the direct voltage network (30), - a module (142) for deactivating the protection module (42) of the control circuit (40) of the MOSFET gates controlled by said short-circuit detection module (141), - at least one MOSFET gate control module (143) configured to control at least one MOSFET (16) in an ideal diode mode in which the MOSFET (16) conducts as soon as the voltage across its terminals is negative.

7. Electrical system (10) according to claim 6, wherein said rotating electrical machine (11) is a permanent magnet machine controlled in normal operation, without short circuit, by pulse width modulation to drive the motor or take power from the generator to supply the continuous electrical network (30).

8. Electrical system (10) according to one of claims 6 or 7, the gate control circuit (40) of the MOSFETs comprises a control input used in normal operation, without short circuit, and a reset input, the reset input being configured to deactivate the protection module (42) of the gate control circuit (40) upon receipt of a deactivation signal.

9. Electrical system (10) according to claim 8, comprising a first MOSFET gate control module for each MOSFET, said first control module comprising a multiplexer comprising a first input configured to receive a normal operation command of the MOSFET, a second input configured to receive an ideal diode mode operation command, a selection input, and an output configured to copy the first input as long as no signal has been received on the selection input and to copy the second input as an output of the multiplexer when the selection input receives a selection signal, the selection signal being received when the MOSFET gate control circuit receives a reset command on its reset input.

10. Electrical system (10) according to one of claims 6 to 9, wherein the electrical protection means (14) further comprise means (145) for measuring the voltage at the terminals of the direct voltage network coupled to the connection terminals and means (146) for comparing the measured voltage to a voltage threshold below which the voltage drop corresponds to a short circuit on the direct voltage network, or means for measuring the current flowing on the direct voltage network coupled to one of said connection terminals and means for comparing the measured current to a current threshold.

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