Electrical system comprising a power battery suitable for activating a short-circuit mode of an electric machine

Abstract

The present invention relates to an electrical system (1) comprising an electric machine (5), a power battery (2) comprising a multilevel inverter distributed within the battery and suitable for supplying power to the electric machine (5), and a diagnostic means (3) suitable for controlling a commanded short-circuit mode of the electric machine (5), wherein the battery (2) comprises at least one current line (21) comprising a plurality of energy storage devices (MCLk) connected in series, wherein each storage device (MCLk) comprises an electrochemical energy storage element (CLk) supplying a voltage and a switching circuit (COMk) comprising an H-bridge, and wherein the diagnostic means (3) is configured to control all of the switching circuits of the battery into the bypass state when the commanded short-circuit mode of the electric machine (5) is activated.

Description

[0001] DESCRIPTION

[0002] TITLE: ELECTRICAL SYSTEM COMPRISING A POWER BATTERY ADAPTED TO ACTIVATE A SHORT-CIRCUIT MODE OF AN ELECTRICAL MACHINE

[0003]

[0001] The present invention claims priority from French application No. 2403673 filed on 10.04.2024, the content of which (text, drawings and claims) is incorporated herein by reference.

[0004]

[0002] The field of the invention relates to an electrical system comprising a battery adapted to activate a controlled short-circuit mode of an electrical machine and a control method.

[0005]

[0003] In the automotive industry, electrified vehicles are equipped with an electrical system comprising a rotating electrical machine, generally of the permanent magnet synchronous machine type, the torque of which must be controlled. When a functional fault in the electrical machine is detected, it is necessary to secure the vehicle and in particular the battery. One measure for protecting the electrical system is the activation of a safe refuge mode, also called "controlled short circuit" or ASC mode for "active short circuit" in English. The functional faults leading to the activation of the controlled short circuit mode may be the loss of control of the electrical machine, an exceeding of the current limit, an overspeed of the electrical machine, the loss of a sensor (rotor position, current, etc.) or the activation of a vehicle collision signal.

[0006]

[0004] Conventionally, the ASC function is an active short-circuit mechanism implemented within standard inverters which is used to bring the rotating electrical machine and the moving vehicle to a safe state quickly. A protection technique is described in document FR3083391 B1 describing a method for diagnosing a power bridge connected to a rotating electrical machine and a protection device configured to detect an abnormal establishment time of an electric current between the terminals of a power component. The safety device is intended to make the power components safe by generating a closing command for the switches connecting the phases of the electrical machine to the ground terminal of the system.

[0007]

[0005] As part of its developments, the applicant has developed a battery architecture known as a distributed multi-level inverter which makes it possible to dispense with the voltage converters usually integrated between a power battery and the power supply network operating at alternating voltage. This architecture has been the subject of several patent applications. Examples include documents WO-A1-2017 / 153366 and WO-A1-2021 / 048477. They describe a cell architecture which comprises current lines formed by storage devices each comprising an electrochemical cell, or a cluster of cells, and a switching circuit forming an H-bridge. The storage devices are connected in series via the switching circuit so as to form the multi-level inverter structure integrated in the battery.This architecture makes it possible to generate an alternating voltage at the battery output that can directly control an electric traction machine or exchange power with the electrical distribution network, for example.

[0008]

[0006] However, for this architecture, the electrical system does not have an inverter. The ASC function cannot therefore be implemented as on a conventional traction chain. There is therefore a need to develop a refuge mode for the electrical machine with respect to all the power components forming the electrical system, and in particular the battery. One objective of the invention is to develop a controlled short-circuit mode function for an electrical system comprising an electrical machine and a power battery with a distributed multi-level inverter.

[0009]

[0007] More specifically, the invention relates to an electrical system comprising an electrical machine, a power battery adapted to electrically supply the electrical machine, a diagnostic means adapted to control a short-circuit mode of the electrical machine,

[0010] - the battery comprising at least one current line connected to a phase branch of the electrical machine,

[0011] - the current line comprising a plurality of energy storage devices connected in series, each storage device comprising two connection terminals, an electrochemical energy storage element providing a voltage and, - a switching circuit comprising an H-bridge whose states are selectively controllable so as to deliver to said connection terminals, in a first state the voltage, in a second state the inverted voltage and in a third state a zero voltage configuring the storage device in a bypass state of the storage element, the switching circuit of each storage device further comprising a redundancy bypass circuit electrically connected to the two connection terminals capable of configuring a fourth redundancy bypass state of the switching circuit.

[0012]

[0008] According to the invention, the redundancy bypass circuit is configured to be active by default and the diagnostic means is configured to control all the switching circuits of the battery in bypass state when the short-circuit mode of the electrical machine is commanded.

[0013]

[0009] According to a variant, the redundancy bypass circuit comprises two power MOSFET transistors mounted head to tail as a common source electrically connected to the two connection terminals of the storage device.

[0014]

[0010] According to one variant, the electrical system comprises a damping circuit connected in parallel to the terminals of the storage element.

[0015]

[0011] There is further provided an electrified vehicle comprising an electrical system according to any one of the preceding embodiments, for example an electrified motor vehicle with an at least partially electrified powertrain comprising such an electrical system.

[0016]

[0012] Further provided is a stationary energy storage system comprising an electrical system according to any of the preceding embodiments.

[0017]

[0013] Further provided according to the invention is a method for controlling an electrical system according to any one of the preceding embodiments for controlling a short-circuit mode of the electrical machine comprising the following steps:

[0018]

[0014] - activation of the short-circuit mode,

[0019]

[0015] - the control of all the battery switching circuits in bypass state.

[0020]

[0016] According to a variant of the method for an electrical system for controlling a piloted short-circuit mode of the electrical machine, all the bypass circuits of the battery switching circuits are controlled in the fourth redundancy bypass state for control in the bypass state.

[0021]

[0017] According to a variant, the method further comprises controlling all the H-bridges of the battery switching circuits in the third state simultaneously with controlling all the bypass circuits when the controlled short-circuit mode of the electrical machine is activated.

[0022]

[0018] According to a variant, the control of all the H-bridges is triggered before the control of all the bypass circuits.

[0023]

[0019] The invention further provides a control unit for an electrical system comprising means specifically configured to implement any variant of the control method.

[0024]

[0020] Further provided is a computer program comprising instructions which, when the program is executed by a control unit of an electrical system, cause the latter to implement any one of the embodiments of the control method for controlling a controlled short-circuit mode of an electrical machine.

[0025]

[0021] Further provided is a computer-readable recording medium comprising instructions which, when executed by a computer, cause the computer to implement any one of the embodiments of the control method for controlling a controlled short-circuit mode of an electrical machine.

[0026]

[0022] The invention controls the integrated multi-level inverter battery to implement a UPS function of the electrical machine. The configuration of this function avoids the need for a power circuit specific to this protection. The development cost of the electrical system is thus reduced.

[0027]

[0023] Other characteristics and advantages of the present invention will appear more clearly on reading the detailed description which follows, comprising embodiments of the invention given as non-limiting examples and illustrated by the appended drawings, in which:

[0028]

[0024] [Fig.1] schematically represents an embodiment of an electrical system according to the invention for controlling the piloted short-circuit mode of an electrical machine.

[0025] [Fig.2] schematically represents an embodiment of a battery storage device adapted to implement the method for controlling the piloted short-circuit mode of an electrical machine according to the invention.

[0029]

[0026] [Fig.3] schematically represents a battery control configuration for implementing the controlled short-circuit mode of an electrical machine according to the invention.

[0030]

[0027] [Fig.4] schematically represents several configurations of a battery storage device adapted for implementing the controlled short-circuit mode of an electrical machine according to the invention.

[0031]

[0028] [Fig.5] schematically represents an electrified vehicle comprising an electrical system according to the invention.

[0032]

[0029] The invention applies to electrified vehicles comprising an electric powertrain driven, at least partially, by an electric machine, i.e. with a fully electric or hybrid motor, preferably motor vehicles, but not only such as aircraft, trucks, tractors, bicycles, ships. More generally, the invention also applies to any stationary energy storage system comprising an electric machine and a power battery adapted to operate as a power generator for a continuous network. The invention applies to any autonomous electrical system such as drones, robots or portable devices which are cited as a non-exhaustive list of application examples.

[0033]

[0030] The invention proposes an electrical system allowing the control of a piloted short-circuit mode of an electrical machine for a battery architecture with multi-level inverters distributed in the battery.

[0034]

[0031] In the present description, the term distributed multilevel inverter in the battery means that the current line or each current line of the battery is formed by a plurality of storage devices connected in series and each storage device comprises an electrochemical energy storage element, consisting of a cell or a cluster of cells, as well as a switching circuit comprising an H-bridge, the control unit comprises a means for controlling the storage devices of the current line according to a reference setpoint and is capable of generating a chosen voltage waveform, alternating and direct, on each current line. This architecture is the subject of a more detailed description in figure 1. The invention proposes to judiciously control the switching circuits in bypass state to trigger the controlled short-circuit mode of an electrical machine.

[0035]

[0032] The term "bypass state" means that a bypass configuration of the power circuit between the connection terminals of a storage device is controlled. This configuration has the effect of disconnecting the storage element in a current line of the battery and isolating it from the other storage elements while maintaining the continuity of service of the system.

[0036]

[0033] Furthermore, an electrochemical energy storage element, also called an electrochemical cell, is an electrochemical element having two electrical connection terminals and having a voltage of a few volts, most often between 2.3V and 4.2V, approximately. The cells can be of the Lithium-ion type (a lithium Nickel Manganese Cobalt oxide NMC or a lithium iron phosphate LFP can be cited as examples of positive electrode active materials), Nickel Cadmium (Ni-cd), Nickel-Metal-Hydride (Ni-MH), Sodium-ion. More precisely, a Lithium-ion cell is composed mainly of a porous positive electrode, a porous negative electrode, a separator and an electrolyte (which can be liquid, polymeric or solid). The operating principle of a Lithium-ion cell is based on the reversible exchange of Lithium ions between the two porous electrodes.

[0037]

[0034] In Figure 1, an embodiment of a polyphase electrical system according to the invention is shown schematically. The system comprises an electrical machine 5, a power battery 2 adapted to electrically supply the electrical machine 5 and a diagnostic means 3 adapted to control a controlled short-circuit mode of the electrical machine 5.

[0038]

[0035] The electrical machine 5 may be a direct current machine or an alternating current machine, preferably whose stator is polyphase, of the permanent magnet synchronous machine type or asynchronous machine. An electrical machine may be used for the production of a motor torque of a traction chain or the production of electrical energy. By way of non-limiting examples, it may be an electric traction machine for an electrified vehicle, an alternator or alternator-starter, or a generator.

[0036] More precisely, the power battery 2 comprises a plurality n of storage devices MCLk forming the multi-level inverter structure distributed in the battery and comprises three current lines 21, 22 and 23 connected to phase branches BP1, BP2 and BP3 and in which the storage devices MCLk are arranged. The MCLk storage devices are connected in series in each current line.The phase branches BP1, BP2 and BP3 allow the battery to be connected to different systems designed to use alternating or direct voltage.

[0039]

[0037] The battery system 2 delivers to its terminals a voltage of several hundred volts between 200 and 1000 volts, for example with a maximum amplitude of 350, 400, 450, 500 or 1000 volts. However, other voltages are possible at lower values ​​24 volts, 36 volts, 48 ​​volts for example, or at higher values ​​of 1500 volts or more, in particular for stationary systems.

[0040]

[0038] Each storage device MCLk comprises an energy storage element CLk, consisting of a single cell or a cluster of cells, and a switching circuit COMk comprising an H-bridge. The storage devices MCLk are interconnected in series via the switching circuits COMk so as to form the distributed multilevel inverter in the battery BAT, which inverter is capable of generating a voltage waveform selected at the terminals of each current line 21, 22 and 23 by the series connection of a controlled selection of storage devices MCLk from the plurality. A cluster of cells CLk may comprise two, three, four, five, six, eight or more cells, forming the cluster voltage. The cells are connected in series, in parallel, or in series and in parallel in a cluster of cells.

[0041]

[0039] Furthermore, each switching circuit COMk comprises two switching parts forming an H-bridge that can be controlled in three different states by a control signal from a control unit 24 of the battery 2 specifically addressing the storage device MCLk. The states are represented by a control variable uik that can take, for example, the values ​​1, 0, -1 representing the three different states controlling respectively in a first state the cluster voltage Vclk, in a second state the inverted voltage -Vclk and in a third state a zero voltage at the connection terminals of the storage device MCLk addressed by the control signal uik.

[0040] Furthermore, this third state can be controlled in the event of a malfunction of a part of the cell cluster, for example a cell at the end of its life, a faulty cell or an anomaly concerning a voltage or temperature sensor.In the event of a failure, the COMk switching circuit isolates the cell cluster while maintaining continuity of service of the current line, the current passing directly through the storage device via the H bridge which is then configured as a bypass in this third state.

[0042]

[0041] More precisely, each switching circuit COMk comprises electronic components, such as power transistors, possibly of the MOSFET (“Metal Oxide Semiconductor Field Effect Transistor”) or HEMT (“High Electron Mobility Transistor” type), controlled by the control signals from the control unit 24.

[0043]

[0042] Thus, an example of a mode of controlling the voltage at the terminals of each storage device MCLk among the set of a totality n of modules can be carried out as a function of a control signal uik according to the following relation:

[0044]

[0044] Vref is the voltage setpoint, and Vclk is the cluster voltage.

[0045]

[0045] Thus, the control unit 24 can control on each voltage line 21, 22 and 23 any voltage waveform formed by amplitude steps composed of the cluster voltages Vclk of each activated cluster as a function of a reference voltage setpoint Vref by connecting the cells in series via the switching circuits COMk. The reference voltage setpoint Vref can be of sinusoidal form with a frequency of 50 Hz, any alternating form, for example square, or can be of constant voltage, for example.

[0046]

[0046] In a preferred variant, without however being obligatory, each switching circuit COMk further comprises a bypass circuit of the switching circuit COMk electrically connected to the connection terminals of the voltage of the storage device MCLk. The bypass circuit is capable of configuring a fourth redundancy bypass state of the switching circuit COMk. The bypass state of the switching circuit COMk can thus be configured in redundancy to guarantee the continuity of service of the electrical system in the event of failure of a component of the storage device, i.e. the storage element, the switching circuit or a control circuit of the storage device. The bypass circuit can be controlled in a closed bypass state and in an open state.Preferably, this circuit is controlled in default redundancy bypass state, i.e. when the electrical system is in standby or shutdown situation, and in open state by activation of a specific command by the system supervision.

[0047]

[0047] More precisely, the third state and the fourth state of bypass control are used during the nominal operation of the battery and can be controlled in the event of a malfunction of the electrical machine, in particular in the event of detection by the diagnostic means 3 of a fault triggering the controlled short-circuit mode.

[0048]

[0048] In the context of the invention, the Vref setpoint can be controlled in response to a request from the diagnostic means 3 to command a zero voltage on each current line between each phase branch of the electrical machine and the ground of the electrical system.

[0049]

[0049] For this purpose, the electrical system 1 comprises a communication network 6 adapted for the exchange of data allowing cooperation between the diagnostic means 3 and the control unit 24 of the battery to trigger and activate the controlled short-circuit mode of the electrical machine. The communication network is for example a CAN (Control Area Network) type network. However, this is not obligatory; alternatively, it is envisaged that the diagnostic means 3 can directly control a control signal from each storage device to control the controlled short-circuit mode of the electrical machine 5.

[0050]

[0050] More specifically, the diagnostic means 3 is provided to periodically carry out diagnostic routines in order to monitor signals representative of a state of the electrical system resulting from a loss of control of the electrical machine 5, an exceeding of a current limit, overspeed of the electrical machine, loss of a sensor (rotor position, current, etc.) or a vehicle collision signal, for example. The diagnostic means 3 is implemented by the control unit 4 of the electrical system.

[0051] Furthermore, it is planned that battery 2 can be connected to one or more external systems via branching of phase branches BP1, BP2 and BP3.

[0051]

[0052] In a first set of branch connections of the phase branches BP1, BP2 and BP3, the battery 2 comprises high-voltage switches, also called high-voltage contactors, intended to electrically connect the battery 2 to an extended electrical supply network RES. Each current line 21, 22 and 23 is connected, via these branch connections, on one side to a network connection switch, and on the other side to a neutral terminal N of the battery. The extended supply network operates at 50Hz or 60Hz alternating voltage and comprises a three-phase line provided with three voltage lines. The battery 2 is adapted to generate three three-phase voltage waves offset by 2TT / 3. The control of each current line is similar, differing only by a 2TT / 3 offset between them. The supply network can also provide a single-phase voltage line.Battery 2 is capable of connecting the three current lines 21, 22 and 23 in series to the RES network.

[0052]

[0053] It should be noted that, thanks to this distributed multi-level inverter architecture in the battery, the electrical system does not include an AC / DC voltage converter between the current lines LT1, LT2 and LT3 and the phase branches BP1, BP2 and BP3 operating in alternating current.

[0053]

[0054] Furthermore, in the case of an embodiment for an electrified vehicle, the battery 2 is the traction battery of the vehicle and the electric machine 5 is the driving machine. Each current line 21, 22, 23 is connected, via a second set of branching of the phase branches BP1, BP2 and BP3, on a first side to the electric machine, and on the other side to a neutral terminal N of the battery.

[0054]

[0055] Furthermore, another set of branches (not shown in the figure) can be provided to connect the battery to a direct voltage bus.

[0055]

[0056] In Figure 2, a preferred embodiment of the storage device is shown schematically. The storage device MCLk comprises the switching circuit COMk, the storage element CLk and two connection terminals S1 and S2. The switching circuit COMk comprises the H-bridge circuit and the bypass circuit CCK. The H-bridge consists of switches arranged, on the one hand, by transistors HS1 and HS2 electrically connected to the positive polarity V+ of the storage element by a current terminal and respectively to terminals S1 and S2 by another current terminal, and on the other hand, by transistors LS1 and LS2 electrically connected to the negative polarity V- of the storage element CLk by a current terminal and respectively to terminals S1 and S2 by another current terminal. The transistors HS1, HS2, LS1 and LS2 are, for example, power transistors of the MOSFET type.

[0056]

[0057] The redundant bypass function is performed by the CCK circuit which comprises two power MOSFET transistors CCk1 and CCk2 mounted head to tail in common source electrically connected to the two connection terminals S1 and S2 of the storage device, respectively, in order to ensure the opening of the CCk bypass circuit regardless of the sign of the voltage at its terminals.

[0057]

[0058] It is intended that the redundancy bypass circuit CCK is a circuit which is active by default (also referred to in English as “normally ON”). Thus when the electrical system 1 of the vehicle is switched off, the storage elements CLk are bypassed via the redundancy bypass circuits CCk, therefore the voltage of the current lines 21, 22, 23 is zero, which makes it possible to guarantee the safety of the user, particularly in the event of manipulation of the battery 2.

[0058]

[0059] The storage device further preferably comprises a snubber circuit SNBk connected in parallel to the terminals of the storage element CLk, designated by the English term "snubber" and consisting of resistors and capacitors. This snubber circuit SNBk makes it possible to avoid overvoltages during switching, overvoltages which are a consequence of the mesh inductance.

[0059]

[0060] Furthermore, for the sake of simplification, the components of the storage device are represented in the lower part of Figure 2 in the form of electrical symbols when all the MOSFET switches are in the open position. This diagram will be used in the remainder of the description to illustrate several bypass configurations that can be implemented when a controlled short-circuit mode is controlled by the electrical system.

[0060]

[0061] In Figure 3, a first configuration of the battery 2 for controlling the piloted short-circuit mode of the electrical machine 5 is shown schematically. The diagnostic means drives all the switching circuits MCLk of the battery 2 into the bypass state. In this first configuration, the storage devices MCLk are driven so that the H-bridge of the switching circuit is driven into the third bypass state where the switches LS1 and LS2 are driven into the closed state. Simultaneously, the bypass circuit CCk is driven into the closed state.

[0061]

[0062] This first configuration offers several advantages. The current flowing through a current line is distributed between the redundancy bypass circuit CCk and the H-bridge line and equally if the resistance characteristics of the MOSFET switches LS1 and LS2 of the H-bridge and the switch of the redundancy bypass circuit CCk are identical.

[0062]

[0063] In an exemplary embodiment of the battery, the current flowing through each current line is equal to approximately 375A as soon as the speed of the electric machine exceeds 3000 rpm. The MOSFET switches are traversed by a current of only approximately 188A, which reduces local heating and provides an increased safety solution at the level of the energy storage battery.

[0063]

[0064] In Figure 4, other configurations of the MCLk storage devices allowing the activation of the controlled short-circuit mode are represented. In a second configuration referenced 4A, all the MCLk storage devices are controlled so that the H-bridge of the switching circuit is controlled in the third bypass state where the switches HS1 and HS2 are controlled in the closed state. Simultaneously, the bypass circuit CCk is controlled in the closed state. This configuration makes it possible to distribute the current generated by the electrical machine between the two lines.

[0064]

[0065] In a third configuration referenced 4B, all the storage devices MCLk of the battery are driven such that only the H-bridge of the switching circuit is driven in the third bypass state where the switches LS1 and LS2 are driven in the closed state. The bypass circuit CCk is open. In a fourth configuration referenced 4C, all the storage devices MCLk are driven such that only the H-bridge of the switching circuit is driven in the third bypass state where the switches HS1 and HS2 are driven in the closed state. Finally, in a fifth configuration referenced 4D, all the storage devices MCLk of the battery are driven such that all the switches of the H-bridge of the switching circuit are open and only the bypass circuit CCk is closed.

[0065]

[0066] Furthermore, the invention provides a method for controlling the electrical system according to the invention for the controlled short-circuit mode of the electrical machine. The method is implemented by the control unit of the electrical system, which may be, for example, the supervisor of an electrified vehicle. The control unit is provided with an integrated circuit computer and electronic memories, the computer and the memories being configured to execute the control method. But this is not mandatory. Indeed, the computer could be external to the control unit, while being coupled to the latter. In the latter case, it may itself be arranged in the form of a dedicated computer comprising a possible dedicated program, for example.Consequently, the control unit, according to the invention, can be produced in the form of software modules (or computer modules (or even "software")), or electronic circuits (or "hardware"), or even a combination of electronic circuits and software modules.

[0066]

[0067] The control method can be implemented in the preferred variant of the system where the battery storage devices include the H-bridge and the redundancy bypass circuits. However, this is not mandatory; the method can also be carried out in the variant without redundancy bypass circuits. The diagnostic function for activating the controlled short-circuit mode is implemented by the control unit. This mode operates the battery via the communication network or the battery directly.

[0067]

[0068] As illustrated in Figure 5, the method comprises a diagnostic step E50 of the electrical system consisting of monitoring information representative of an electrical fault such as loss of control of the electrical machine, exceeding of a current limit, overspeed of the electrical machine, loss of a sensor (rotor position, current, etc.) or activation of a vehicle collision signal.

[0068]

[0069] In the event of detection E51 of a fault, the method comprises a step E52 of activating the controlled short-circuit mode of the electrical machine. The activation step E52 consists of generating a bypass command to the battery by activating an electrical signal directly connected to a control signal of the switches of the H-bridges and / or the switches of the redundancy bypass circuit. Alternatively, the activation is carried out by generating a control signal through a communication network of the electrical system.

[0069]

[0070] Then, the method includes a step E53 of controlling all the switching circuits of the battery in bypass state. In this way, each phase branch of the electrical machine is connected to the ground of the electrical system when the short-circuit mode is activated.

[0070]

[0071] Several variations of the process are possible.

[0071]

[0072] In a first variant, all H-bridges of the battery switching circuits are controlled in the third state for control in the bypass state by the MOSFET switches electrically connected to the positive terminal.

[0072]

[0073] In a second variant, all H-bridges of the battery switching circuits are controlled in the third state for control in the bypass state by the MOSFET switches electrically connected to the negative terminal.

[0073]

[0074] In a third preferred variant, simultaneously with the H-bridges, all bypass circuits of the battery switching circuits are controlled in the fourth redundancy bypass state. This variant of the method makes it possible to distribute the current between the lines of the H-bridge and the redundancy circuits. According to this third variant, the control of all H-bridges is triggered before the control of all bypass circuits in order to avoid a short circuit between the positive polarity terminal and the negative polarity terminal of an electrochemical energy storage element.

[0074]

[0075] Furthermore, it is envisaged that, in a situation where a switching circuit of one of the storage devices has failed, upon detection of the failure by a battery detection means provided for this purpose, the control method is configured to specifically activate the redundancy bypass circuit of the failed storage device when the controlled short-circuit mode is activated. The failure may be a short-circuit fault or an open-circuit fault of one of the MOSFET switches.

[0075]

[0076] In a fourth variant of the method, all battery redundancy bypass circuits are controlled in the fourth redundancy bypass state. Only these redundancy circuits are used to control the controlled short-circuit mode.

[0076]

[0077] In Figure 6, an embodiment of the electrical system is shown for an electrified vehicle with an at least partially electrified powertrain. The vehicle comprises at least one electrical drive machine 64 capable of transmitting torque to the drive wheels 62 of the vehicle through a transmission 61. The electrical machine 64 may be three-phase. The vehicle comprises an electrical system comprising the battery 60 according to the architecture with a multi-level inverter distributed in the battery in accordance with the description given in Figure 1. The battery comprises at least one current line, preferably three current lines.

[0077]

[0078] The vehicle further comprises an interface for recharging the battery 68 from a power supply network operating at alternating voltage. The recharging interface 68 is a recharging box electrically connecting the terminals of the battery 60 to the terminal for recharging. The recharging interface 68 is also suitable for rapid recharging at direct voltage. The battery system 60 is advantageous in that its control unit 65 adapts the voltage wave to alternating form or direct wave form without using a voltage converter. The vehicle further comprises a supervision system 66 cooperating with the control unit 65 of the battery system 60. The battery system 60 can be directly electrically connected to the electric motor 64, thus improving its energy efficiency in traction.The battery can further be connected to a high voltage DC bus 63, for example operating at a nominal voltage of between 350 and 800 volts, for example 450 volts, and to a low voltage on-board network 67 operating at a nominal voltage of type 12 volts. In addition, the power electronics 69 comprises a DC / DC converter connecting the voltage bus to the on-board network 67 (450 volts / 12 volts) comprising a service battery.

[0078]

[0079] Some or all of the functions of the vehicle are controlled by the supervision system 66. For the implementation of the invention, the supervision system 66 comprises a diagnostic means adapted to control a controlled short-circuit mode of the electrical machine 64 and in which the diagnostic means is configured to control all the switching circuits of the battery in bypass state when the controlled short-circuit mode of the electrical machine 64 is activated.

[0079]

[0080] Further contemplated is a stationary electrical system comprising an electrical machine. This electrical system is in accordance with that of Figure 1 and comprises diagnostic means adapted to control a controlled short-circuit mode of the electrical machine and in which the diagnostic means is configured to control all the switching circuits of the battery in a bypass state when the controlled short-circuit mode of the electrical machine is activated.

[0080]

[0081] The invention is described in the above by way of example. It is understood that the person skilled in the art is able to produce different variant embodiments of the invention by associating, for example, the different characteristics above taken alone or in combination, without departing from the scope of the invention.

Claims

CLAIMS 1. Electrical system (1) comprising an electrical machine (5), a power battery (2) adapted to electrically supply the electrical machine (5), a diagnostic means (3) adapted to control a short-circuit mode of the electrical machine (5), - the battery (2) comprising at least one current line (21) connected to a phase branch (BP1) of the electrical machine (1), -the current line (21) comprising a plurality of energy storage devices (MCLk) connected in series, each storage device (MCLk) comprising two connection terminals (S1, S2), an electrochemical energy storage element (CLk) providing a voltage (Vclk) and -a switching circuit (COMk) comprising an H-bridge whose states can be selectively controlled so as to deliver to said connection terminals, in a first state the voltage (Vclk), in a second state the inverted voltage and in a third state a zero voltage configuring the storage device (MCLk) in a bypass state of the storage element (CLk), the switching circuit of each storage device further comprising a redundancy bypass circuit (CCk) electrically connected to the two connection terminals (S1, S2) capable of configuring a fourth redundancy bypass state of the switching circuit (COMk), the system (1) being characterized in that -the redundancy bypass circuit (CCk) is configured to be active by default, -the diagnostic means (3) is configured to control all the switching circuits of the battery in bypass state when the short-circuit mode of the electrical machine (5) is commanded.

2. Electrical system (1) according to claim 1, characterized in that the redundancy bypass circuit (CCk) comprises two power MOSFET transistors (CCk1, CCk2) mounted head-to-tail in common source connected electrically to the two connection terminals (S1, S2) of the storage device (MCLk).

3. Electrical system according to one of the preceding claims, characterized in that it comprises a damping circuit (SNBk) connected in parallel to the terminals of the storage element (CLk), 4. Electrified motor vehicle with at least partially electrified powertrain comprising an electrical system according to one of the preceding claims.

5. Stationary energy storage system comprising an electrical system according to one of claims 1 to 3.

6. Method for controlling an electrical system according to one of claims 1 to 3 for controlling a short-circuit mode of the electrical machine (5) comprising the following steps: - activation (E52) of the short-circuit mode, - control (E53) of all battery switching circuits in bypass state.

7. Control method according to claim 6 wherein all the bypass circuits (CCk) of the switching circuits (COMk) of the battery (2) are controlled in the fourth redundancy bypass state for control in the bypass state.

8. Control method according to claim 7 further comprising controlling all the H-bridges of the switching circuits (COMk) of the battery (2) in the third state simultaneously with controlling all the bypass circuits (CCk) when the controlled short-circuit mode of the electrical machine (5) is activated.

9. Control method according to claim 8 wherein the control of all the H-bridges is triggered before the control of all the bypass circuits (CCk).

10. Control unit of an electrical system according to one of claims 1 to 3 comprising means specifically configured to implement the control method according to any one of claims 6 to 9.

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