Method of protecting a power supply circuit of an electrical machine

Abstract

A computer-implemented method for protecting an electrical circuit for powering a rotating electrical propulsion machine, this circuit employing chains of electrical modules, each chain being connected to a phase of the electrical machine by controllable switches, the modules comprising: - a primary terminal and a secondary terminal, the primary terminal being connected to the secondary terminal of another module and / or the secondary terminal is connected to the primary terminal of another module, - an electrical energy storage unit, and - at least one controllable switch capable of connecting the electrical energy storage unit to the primary and secondary terminals of the module,the method being characterized in that it comprises a step of controlling the circuit switches such that all the modules of all the chains have their electrical energy storage unit disconnected from the terminals of the module and a step of controlling such that all the chains are connected to the phases of the electrical machine.,

Description

Title of the invention: Method for protecting a power supply circuit of an electrical machine

[0001] The present application refers to a computer-implemented method of protecting a power supply circuit of a rotating electrical machine for propelling a vehicle.

[0002] In a known example, in particular from application US8395280B2, such a circuit uses chains of electrical modules, each chain being connected to a phase of the electrical machine by controllable switches, the modules comprising:

[0003] -a primary terminal and a secondary terminal, the primary terminal being connected to the secondary terminal of another module and / or the secondary terminal is connected to the primary terminal of another module,

[0004] - an electrical energy storage unit,

[0005] - at least one controllable switch capable of connecting or disconnecting the unit of electrical energy storage, at the primary and secondary terminals of the module, and

[0006] - a primary terminal and a secondary terminal, the primary terminal being connected to the secondary terminal of another module and / or the secondary terminal is connected to the primary terminal of another module

[0007] There is a need to protect such a power supply circuit for a rotating electrical machine for propelling a vehicle, in particular in the case where this rotating electrical machine can no longer be correctly controlled by a control unit within the circuit while it is still rotating. Indeed, the electrical machine can then be a generator, and there is a need to discharge it without damaging the power supply circuit, until the moment when control of the engine is restored or until the vehicle is stopped.

[0008] The invention aims to meet this need and achieves this through one of its aspects, by means of a computer-implemented method for protecting an electrical circuit for powering a rotating electrical propulsion machine, this circuit employing chains of electrical modules, each chain being connected to a phase of the electrical machine by controllable switches and all chains being connected to the same common point, the modules comprising:

[0009] - a primary terminal and a secondary terminal, the primary terminal being connected to the secondary terminal of another module and / or the secondary terminal is connected to the primary terminal of another module,

[0010] - an electrical energy storage unit, and

[0011] - at least one controllable switch capable of connecting or disconnecting the unit of electrical energy storage, at the primary and secondary terminals of the module,

[0012] the method being characterized in that it comprises a step of controlling the circuit switches so that all the modules of all the chains have their electrical energy storage unit disconnected from the terminals of the module and a step of controlling so that all the chains are connected to the phases of the electrical machine.

[0013] This method makes it possible to disconnect the energy storage units from the modules of the chain to which they belong, and to allow the current of the phases of the rotating electrical machine to pass so that it can dissipate in the rest of the circuit, more particularly in the modules of the chains.

[0014] According to the invention, the modules are arranged within the chain in such a way that their primary terminal is connected to the secondary terminal of another module and their secondary terminal is connected to the primary terminal of another module, with the exception of a module whose primary terminal is connected to the first terminal of the chain and a module whose secondary terminal is connected to the second terminal of the chain.

[0015] The modules may comprise an H-shaped switching bridge comprising controllable switches, each midpoint of the bridge being connected to one of the terminals of the module, the electrical energy storage unit being arranged in a branch in parallel with the switching arms, the method then comprising:

[0016] - Controlling the switches of all modules of all chains in such a way that the switches of the switching bridge connected to the same terminal of the electrical energy storage unit are controlled to be in the closed position, and the other switches are controlled to be in the open position, and

[0017] - The control of the switches connecting the chains to the phases of the motor to be in closed position.

[0018] Alternatively, the modules may comprise an H-shaped switching bridge comprising controllable switches, each midpoint of the bridge being connected to one of the terminals of the module, the electrical energy storage unit being arranged in a branch in parallel with the switching arms, and at least one module may comprise a bidirectional switching cell arranged between its primary terminal and its secondary terminal, this switching cell comprising at least one controllable semiconductor switch, the method then comprising:

[0019] - The control of the at least one switch of the at least one switching cell to be in the closed position, and / or

[0020] - Controlling the switches of all modules of all chains in such a way that the switches of the switching bridge connected to the same terminal of the electrical energy storage unit are driven to be in the closed position, and the other switches are driven to be in the open position, and

[0021] - The control of the switches connecting the chains to the phases of the motor to be in closed position.

[0022] The invention also has the aspect of an electrical circuit for powering a rotating electrical machine for propelling a vehicle comprising

[0023] - a polyphase electric machine,

[0024] - a plurality of chains of electrical modules, the modules comprising:

[0025] - a primary terminal and a secondary terminal, the primary terminal being connected to the secondary terminal of another module and / or the secondary terminal being connected to the primary terminal of another module,

[0026] - an electrical energy storage unit,

[0027] - at least one controllable switch capable of connecting or disconnecting the unit of electrical energy storage at the primary and secondary terminals of the module

[0028] - a switch system comprising a set of switches allowing for each string connect it to the terminals of one phase of the electrical machine and

[0029] - a control unit, capable of controlling the switches within the electrical circuit, comprising the means for implementing the method according to any preceding claim.

[0030] The modules may comprise an H-shaped switching bridge comprising controllable switches, each midpoint of the bridge being connected to one of the terminals of the module, the electrical energy storage unit being arranged in a branch in parallel with the switching arms.

[0031] The set of switches of the switch system can allow each string to be connected to a phase of the electrical machine to which this string is dedicated.

[0032] The circuit may comprise an input interface capable of being connected to a charging station, the switch system then comprising a second set of switches allowing each chain to be connected to the input interface.

[0033] The electrical energy storage unit within the modules may have a nominal voltage of between 3 and 60V. For example, the nominal voltage of the electrical energy storage unit may be 5, 12, 24 or 48V.

[0034] Other nominal voltage values ​​are possible, notably greater than 60V.

[0035] All or part of the modules of the plurality of chains may comprise a bidirectional switching cell arranged between their primary terminal and its secondary terminal, this switching cell comprising at least one controllable semiconductor switch.

[0036] The presence of this switching cell between the terminals of the modules makes it possible to achieve redundancy when it is desired to disconnect the storage unit. of energy from one of the modules to the rest of the chain. Thus, if the switching cell of said module is defective, it is possible to disconnect the energy storage unit from this module by controlling the switches of the switching bridge, and if one of the switches of the switching bridge is defective, it is possible to disconnect the energy storage unit from the rest of the chain by controlling the switching cell between the terminals of the module. This redundancy can make a circuit using a chain of modules such as described more resistant to malfunctions, extend its service life, and meet a safety requirement for the vehicle user.

[0037] The switching cell between the primary terminal and the secondary terminal of the modules may comprise a bidirectional transistor, in particular a four-quadrant GaN-based power transistor.

[0038] Alternatively, the switching cell between the primary terminal and the secondary terminal of the modules may comprise two unidirectional transistors mounted in antiparallel, in particular MOS field effect transistors or bipolar transistors.

[0039] Alternatively, the switching cell between the primary terminal and the secondary terminal of the modules may comprise a microelectromechanical system switch.

[0040] The switching cell between the primary terminal and the secondary terminal is different from a mechanical relay.

[0041] The switches of the switching bridge within the module and the switching cell may be of the same type.

[0042] The energy storage unit within the modules can be arranged in a branch that is devoid of switches. In other words, the electrical energy storage unit is mounted between two nodes of the electrical circuit of the module and is not in series between these two nodes with any switch.

[0043] The first and second terminals of the chain can define the single output voltage of the chain.

[0044] This means that there is no intermediate output terminal within the chain, i.e. an output terminal connected both to the primary terminal of a first module and to the secondary terminal of another module in the chain, this primary terminal and this secondary terminal being connected together.

[0045] The number of chains implemented in the plurality of chains may be greater than or equal to the number of phases of the rotating electrical machine.

[0046] The switch system can allow each string of the plurality of strings to be connected to the terminals of a phase of the electrical machine to which this string is dedicated. In other words, a given string can only be connected to a single phase of the stator of the electrical machine.

[0047] The electrical circuit may be reversible, i.e. the switches within the circuit may be controlled so that the strings of modules supply an alternating voltage across the input interface.

[0048] The circuit control unit may be single or comprise a main control unit and several subsidiary control units, for example one subsidiary control unit per chain in the circuit and / or one subsidiary control unit per module.

[0049] The rotating electrical machine is for example a synchronous machine, for example a three-phase synchronous machine or a synchronous machine whose stator electrical winding defines a double three-phase system. The stator electrical winding is for example formed by wires or by conductive bars connected to each other.

[0050] In all of the above, the rotor may be a claw rotor. This rotor then comprises a first and a second nested pole wheels, the first pole wheel defining a series of claws of generally trapezoidal shape, each claw extending axially towards the second pole wheel, the second pole wheel defining a series of claws of generally trapezoidal shape, each claw extending axially towards the first pole wheel. A permanent magnet may be received between two consecutive claws circumferentially speaking for the rotor.

[0051] Alternatively, the rotor may be other than a claw rotor, for example comprising a stack of laminations or being a cage rotor.

[0052] When the rotating machine is a synchronous machine, it may have a wound rotor or a permanent magnet rotor.

[0053] The rotating electrical machine may have a rated electrical power of 25kW, 100kW, 200kW, or more.

[0054] The invention also has as an aspect a computer program product, comprising instructions which cause the control unit of the power supply circuit claim as described previously to implement the steps of the protection method as described.

[0055] The invention also has the aspect of a computer-readable medium, on which the computer program product as described above is recorded.

[0056] The invention may be better understood by reading the following description of non-limiting examples of its implementation:

[0057] [Fig.1a] represents a module intended to be implemented within a chain of electrical modules of a circuit for the power supply of a rotating electrical machine.

[0058] [Fig.lb] represents a variant of the module represented in [Fig.la], comprising a switching cell.

[0059] [Fig.2a] represents a chain of modules according to [Fig.1a] or 1b,

[0060] [Fig.2b] represents an example of output voltage of a string of modules according to [Fig.2a] for the power supply of an electric machine.

[0061] [Fig.2c] represents an example of input voltage of a string of modules according to [Fig.2a] allowing the electrical energy storage units within the modules to be charged.

[0062] [Fig.3] represents a circuit for supplying a rotating electrical machine for propelling a vehicle, using a plurality of module chains according to [Fig.2a].

[0063] [Fig.4a] represents the steps of the method when the modules of the chains of the circuit according to [Fig.3] are according to [Fig.1a].

[0064] [Fig.4b] represents the steps of the method the modules of the chains of the circuit according to [Fig.3] are according to [Fig.lb].

[0065] [Fig. 1a] shows a module 10 intended to be implemented within a chain of electrical modules of a circuit for powering a rotating electrical machine.

[0066] The module 10 as shown in [Fig. 1a] comprises a primary terminal 11a and a secondary terminal 11b, the voltage between terminals 11a and 11b being denoted Vm.

[0067] The module 10 also comprises an electrical energy storage unit 12, of nominal voltage Vc. This electrical energy storage unit may be a cell of a battery employing a plurality of cells, and may have a nominal voltage of between 3 and 60V for example. This energy storage unit 22 is arranged in a branch in parallel with a switching bridge 13, this branch not comprising switches. This switching bridge 13 is mounted in an H shape and comprises controllable switches 14a, 14b, 14c, 14d, arranged on either side of the midpoints 13a and 13b, these midpoints being connected respectively to the primary terminal 11a and the secondary terminal 11b of the module 10a. In the example shown in [Fig.la], the switches 14a, 14b, 14c, 14d are MOS field effect transistors.

[0068] When a control unit controls the switches of the switching bridge 13 such that the switches 14a, 14d are in the closed position and the switches 14b, 14c are in the open position, the voltage Vm between the terminals 11a and 11b of the module 10 is equal to Vc. When the switches 14b, 14c are in the closed position and the switches 14a, 14d are in the open position, the voltage Vm between the terminals 11a and 11b of the module 10 is equal to -Vc.

[0069] When a control unit drives the switches 14a, 14b to be in the open position and the switches 14c, 14d to the closed position, or drives the switches 14a, 14b to be in the closed position and the switches 14c, 14d to the open position, the voltage Vm between the terminals 11a and 11b of the module 10 is zero, the energy storage unit being functionally disconnected from the terminals 11a and 11b of the module 10.

[0070] In [Fig.lb] a variant of the module 10 of [Fig.la] is shown. This module 10 comprises a bidirectional switching cell between its primary 11a and secondary 11b terminals, this switching cell comprising in [Fig.2b] a controllable switch 15 being a four-quadrant gallium nitride (GaN) based transistor.

[0071] The presence of the switch 15 makes it possible to functionally disconnect the energy storage unit 12 from the module 10 in a simple manner, by controlling only the switch 15, or in a more robust manner by also controlling the switches of the switching bridge 13 of the module 10a.

[0072] In [Fig.2a] a chain 30 of four modules 31, 32, 33, 34 is shown. In this example each module is identical and according to the module 10 of [Fig. 1a] or 1b. The modules 31, 32, 33, 34 are chained together by their primary and secondary terminals between the two terminals 37a 37b of the chain. More precisely, the module 31 is connected to the first terminal 37a of the chain 30 by its primary terminal and to the primary terminal of the module 32 by its secondary terminal, the module 32 is connected to the primary terminal of the module 33 by its secondary terminal, the module 33 is connected to the primary terminal of the module 34 by its secondary terminal and the module 34 is connected to the second terminal 37b of the chain 30 by its secondary terminal.

[0073] The chain 30 has a single output voltage which is defined between its two terminals 37a and 37b. Regardless of the value that can be taken by this output voltage, it will be designated Vs hereinafter. In the example shown in Figure 2, the electrical energy storage units within the four modules 31, 32, 33, 34 being identical and of nominal voltage Vc, the voltage Vs can take as a value all the positive or negative integer multiples of Vcentre -4*Vc and 4*Vc when these electrical energy storage units are capable of supplying a voltage.

[0074] [Fig.2b] shows a graph 35 representing an example of alternating voltage Vs generated by the module chain 30 shown in [Fig.2a]. This generated alternating voltage Vs is suitable for powering a rotating electrical machine, it is periodic with period Ti and its shape is comparable to a sine wave.

[0075] At times 0, tb t2, and t3, the modules 31, 32, 33, 34 of the chain 30 are controlled successively so that the voltage between their terminals is equal to Vc, the maximum voltage of the alternating voltage generated Vs between two successive times becoming equal to Vc, 2* Vc, 3* Vc and 4*VC respectively. By controlling a module, we mean controlling the switches within said module in order to obtain the desired voltage between its terminals.

[0076] At times t4, t5, t6 the modules 31, 32, 33, 34 of the chain 30 are controlled successively so that the voltage between their terminals is equal to 0, the maximum voltage of the generated alternating voltage 35 between two successive times becoming equal to 3*VC, 2* Vc and Vc respectively.

[0077] The time interval between instants 0 and t7 corresponds to the positive part of the period Ti of the alternating voltage 35.

[0078] The order of control of the modules 31, 32, 33, 34 between times 0 and t7 may correspond, for example, to the state of charge of the electrical energy storage unit within the modules 31, 32, 33, 34. In order to balance the state of charge of the energy storage units contained in the modules 31, 32, 33, 34, the modules may, for example, be controlled at times 0, tb t2, and t3 according to the decreasing order of state of charge of their electrical energy storage unit and the increasing order at times t4, t5, t6 and t7. Thus, the storage unit being the most charged among the modules will be discharged for a longer time and the least charged storage unit will be discharged for a shorter time, extending the autonomy of the chain.

[0079] At times t7, t8, t9, and ti0, the modules 31, 32, 33, 34 of the chain 30 are controlled successively so that the voltage between their terminals is equal to -Vc, the maximum voltage of the generated alternating voltage 35 between two successive times becoming equal to -Vc, -2* Vc, -3* Vc and -4*VC respectively. At times tu, ti2, and tn, modules 31, 32, 33, 34 of the chain 30 are controlled successively so that the voltage between their terminals is equal to 0, the maximum voltage of the generated alternating voltage 35 between two successive times becoming equal to -3*VC, -2* Vc and -Vc respectively.

[0080] The time interval between instants t7 and tM corresponds to the negative part of the period Ti of the alternating voltage Vs.

[0081] The order of control of the modules 31, 32, 33, 34 between the times t7 and tn may correspond for example to the state of charge of the electrical energy storage unit within the modules 31, 32, 33, 34, 35. In order to balance the state of charge of the energy storage units contained in the modules 31, 32, 33, 34, the modules may for example be controlled according to the decreasing order of state of charge of their electrical energy storage unit between the times t7, t8, t9, and t10 and the increasing order at the times t1, t2, and t1.

[0082] Between two successive instants, a module can be controlled so that the voltage between its terminals passes successively from Vc to 0 and vice versa during the positive part of the period Ti or -Vc to 0 and vice versa during the negative part of the period Ti. period Ti, for example by pulse width modulation. This reduces harmonic distortions of the generated AC voltage 35.

[0083] The time intervals between two successive instants 0, tl, t2, t3, etc. may be all or partially identical.

[0084] [Fig.2c] shows a graph 37 representing an example of charging of the energy storage units within the modules of the chain 30 shown in [Fig.2a] when an alternating voltage Vs is applied to the terminals of said chain.

[0085] The voltage Vs shown in [Fig.2c] is a sinusoidal alternating voltage suitable for being applied to the terminals 37a 37b of the chain 30 of Figure 2. In the example shown, the voltage Vs has a maximum voltage and a minimum voltage of 4*Vcet and -4*Vcrespectively, and is periodic with a period T2. This alternating voltage can come from a charging station, connected to the terminals of the chain 30.

[0086] In the example shown in [Fig.2c], during the time interval 41 between the instant O and the instant t26, the instants when the voltage Vs is zero, a module of the chain 30, for example the module 31, is controlled so that the voltage between its terminals is equal to Vc. As a result, during the time interval 41 the electrical energy storage unit of the module 31 is charged. During the time interval 42 between the instant t20 and the instant t25, the instants when the voltage 37 is equal to Vc, another module of the chain 30, for example the module 32, is controlled so that the voltage between its terminals is equal to Vc. As a result, during the time interval 42 the electrical energy storage unit of the module 32 is charged.During the time interval 43 between the instant t2i and the instant t24, the instants when the voltage 37 is equal to 2*VC, another module of the chain 30, for example the module 33, is controlled so that the voltage between its terminals is equal to Vc. As a result, during the time interval 43 the electrical energy storage unit of the module 33 is charged. During the time interval 44 between the instant t22 and the instant t23, the instants when the voltage 37 is equal to 3*VC, another module of the chain 30, for example the module 34, is controlled so that the voltage between its terminals is equal to Vc. As a result, during the time interval 44 the electrical energy storage unit of the module 34 is charged.

[0087] Similarly, during the time intervals 45, 46, 47 and 48, during the negative half-period of the period T2 of the alternating voltage Vs, the modules 31, 32, 33, 34 of the chain 30 are successively controlled so that the voltage between their primary and secondary terminals is equal to -Vcentre the instants when the alternating voltage Vs is equal to 0, -Vc, -2*VC and -3*Vc respectively so that their respective electrical energy storage unit is charged during these respective time intervals.

[0088] The order of control of the modules 31, 32, 33, 34 may correspond for example to the state of charge of the electrical energy storage unit within the modules 31, 32, 33, 34. In order to balance the state of charge of the electrical energy storage units contained in the modules 31, 32, 33, 34, the modules may for example be charged during the intervals 41, 42, 43, 44 respectively according to the increasing order of state of charge of their electrical energy storage unit. Thus, the most discharged electrical energy storage unit will be charged for a longer time and vice versa. This increasing order may be applied similarly for the intervals 45, 46, 47, 48. Balancing the recharging between the electrical energy storage units makes it possible to reduce the overall recharging time of the chain 30.

[0089] Between two successive instants, a module can be controlled so that the voltage between its terminals changes successively from Vc to 0 and vice versa during the positive part of the period T2 or -Vc to 0 and vice versa during the negative part of the period 36, for example by pulse width modulation. This makes it possible to reduce harmonic distortions when charging the electrical energy storage unit.

[0090] [Fig.3] represents a circuit 100, intended to be integrated within an electrically powered vehicle, using chains 30 according to [Fig.2a].

[0091] The circuit 100 comprises an input interface 101. This input interface is intended to be connected for example to a charging station for an electrically powered vehicle, capable of supplying a single- or polyphase alternating electric voltage or a direct voltage.

[0092] In the example shown in [Fig.3], the input interface 101 comprises three terminals lOlx, lOly, lOlz, capable of being connected to a respective phase of a three-phase alternating voltage. The interface 101 comprises an additional terminal lOln capable of being connected to the neutral of an alternating voltage. When a vehicle charging station connected to the input interface supplies a direct voltage or a single-phase alternating voltage, an interconnection circuit (not shown) arranged between this charging station and the input interface 101 of the circuit 100 makes it possible to distribute the voltage supplied to the three terminals lOlx, lOly and lOlz.

[0093] The circuit 100 comprises a rotating electrical machine 102. In the example shown in [Fig.3], the electrical machine 102 is a polyphase machine, comprising three phases, denoted 102x, 102y and 102z.

[0094] A control unit 109 is present in the circuit 100. The control unit 109 may be a processor or an integrated circuit, for example an FPGA or an ASIC, comprising the means for implementing the control functions of the circuit 100 and for controlling the set of switches within the circuit 100.

[0095] The circuit 100 as shown comprises a plurality of chains 103 composed of three chains 30. These three chains are according to the chain 30 shown in [Fig.2a] and are composed of a plurality of electrical modules 10 according to [Fig.1a] or 1b. In this example, the chains 30 each comprise four identical modules 10 and according to the module 10 shown in [Fig.1a] or 1b.

[0096] The strings 30 of [Fig.3] can be connected to a respective phase 102x, 102y, 102z of the electrical machine 102 by closing the switches of the plurality of switches 107.

[0097] When the strings 30 are connected to a respective phase 102x, 102y, 102z of the electrical machine 102, the control unit 59 can control the switches of the plurality of strings 103 so that they each supply an alternating voltage to the phases 102x, 102y, 102z of the electrical machine 102. As an example, this supplied voltage can be such as the voltage 35 shown in [Fig.2b], the voltages generated by the strings 30 being able to be phase-shifted by 120 degrees between them.

[0098] When the strings 30 are connected to a respective phase 102x, 102y, 102z of the electrical machine 102, and the electrical machine 102 is generating an alternating voltage, for example during regenerative braking, the control unit 109 can control the switches of the plurality of strings 103 so that the electrical energy storage units of the modules 10 can be recharged from this alternating voltage.

[0099] In the example shown in [Fig.3], the strings 30 can be connected to a respective terminal lOlx, lOly, lOlz of the input interface by closing the switches of the plurality of switches 106. When connected to the input interface, the strings are capable of receiving an alternating or direct voltage supplied by a charging station connected to the input interface.

[0100] In the example shown in [Fig.3], the circuit 100 is reversible, that is to say that the control unit can control the switches within the circuit in such a way that the chains provide an alternating voltage to the terminals of the input interface 101. As an example, the chains can generate a voltage such as the voltage 35 shown in [Fig.2b], the voltages generated by the chains 30 being able to be phase-shifted by 120° between them.

[0101] [Fig.4a] shows the steps of a method for protecting the circuit 100 of [Fig.3]. In the example shown in [Fig.4a], the modules 10 of the chains 30 of the circuit 100 are identical and according to [Fig.1a].

[0102] This method makes it possible to protect the circuit 100 when the electrical machine 102 is generating and its phases need to be discharged, for example when control of the machine 102 is lost by the control unit 109 while the machine 102 is running, before being able to stop a vehicle using the circuit 100.

[0103] In a first step 201, the switches of all the modules 10 are controlled in such a way that their energy storage unit 12 is disconnected from their primary terminal 11a and secondary terminal 11b.

[0104] More precisely, during step 201, the switches 14a, 14b of the switching bridge 13 of all the modules 10 are driven to be in the open position and the switches 14c and 14d are driven to be in the closed position. It is also possible to instead drive the switches 14a and 14b to be in the closed position and the switches 14c and 14d to be in the open position.

[0105] During step 202, the switches 107 connecting the phases 102x, 102y, 102z of the electrical machine 102 are controlled to be in the closed position, the chains 30 then being functionally connected to the phases of the electrical machine 102.

[0106] Thus, the phases 102x, 102y, 102z of the electrical machine 102 are connected to the rest of the circuit 100, the currents generated by these phases can dissipate in the circuit, and the energy storage units 12 of the modules 10 of the chains 30 are protected from these currents.

[0107] In a variant shown in [Fig.4b], the modules 10 of the chains 30 of the circuit 100 are identical and according to [Fig.lb], and therefore comprise a bidirectional switching cell comprising a switch 15.

[0108] In a first step 211, the switches 15 of the switching cells within the modules 10 are controlled to be in the closed position. Thus the electrical energy storage unit 12 within the modules 10 is disconnected from the primary 11a and secondary 11b terminals of their respective module.

[0109] During a step 212 the switches of the switching bridges 13 of the modules are controlled so as to provide redundancy to the disconnection of the energy storage unit 12 by the switching cell 15.

[0110] More precisely, during step 212, the switches 14a, 14b of the switching bridge 13 of all the modules 10 are driven to be in the open position and the switches 14c and 14d are driven to be in the closed position. It is also possible to instead drive the switches 14a and 14b to be in the closed position and the switches 14c and 14d to be in the open position. [YES] During step 213, the switches 107 connecting the phases 102x, 102y, 102z of the electrical machine 102 are controlled to be in the closed position, the chains 30 then being functionally connected to the phases of the electrical machine 102

[0112] The invention is not limited to what has been described with reference to the figures.

[0113] Step 211 of [Fig.4b] may be optional, or step 212 may be optional.

[0114] The control unit 109 may comprise a main control unit and several subsidiary control units, for example one subsidiary control unit per chain 30 and 110, and one subsidiary control unit per module 10, the functions of circuit control and control of switches within the circuit being distributed within the main and subsidiary control units.

[0115] The switching cell within the module 10 of [Fig. 1b] may comprise two unidirectional transistors connected in antiparallel, for example MOS field effect transistors or bipolar transistors, or an electromechanical system switch.

Claims

Claims

1. A computer-implemented method for protecting an electrical circuit (100) for powering a rotating electrical propulsion machine (102), said circuit (100) employing strings (30) of electrical modules (10), each string (30) being connected to a phase (102x, 102y, 102z) of the electrical machine (102) by controllable switches (107), the modules (10) comprising: - a primary terminal (11a) and a secondary terminal (11b), the primary terminal (11a) being connected to the secondary terminal (11a) of another module (10) and / or the secondary terminal (11b) is connected to the primary terminal (11a) of another module (10), - an electrical energy storage unit (12), and - at least one controllable switch (14a, 14b, 14c, 14d, 15) capable of connecting the electrical energy storage unit (12) to the primary (11a) and secondary (11b) terminals of the module (10), the method being characterized in that it comprises a step of controlling (202, 211, 212) the switches of the circuit (100) so that all the modules (10) of all the chains (30) have their electrical energy storage unit (12) disconnected from the terminals (11a, 11b) of the module (10) and a step of controlling (201, 210) so that all the chains (30) are connected to the phases (102x, 102y, 102z) of the electrical machine (102).

2. Method according to the preceding claim, the modules (10) comprising an H-shaped switching bridge (13) comprising controllable switches (14a, 14b, 14c, 14d), each midpoint (13a, 13b) of the bridge (13) being connected to one of the terminals (11a, 11b) of the module (10), the electrical energy storage unit (12) being arranged in a branch in parallel with the switching arms, the method comprising: - The control (201) of the switches of all the modules (10) of all the chains (30) in such a way that the switches (14a, 14, 14c, 14d) of the switching bridge (13) connected to the same terminal of the electrical energy storage unit (12) are controlled

3.

4. to be in the closed position, and the other switches (14a, 14b, 14c, 14d) are driven to be in the open position, and - The control (202) of the switches (107) connecting the chains (30) to the phases of the motor (102x, 102y, 102z) to be in the closed position. Method according to claim 1, the modules (10) comprising an H-shaped switching bridge (13) comprising controllable switches (14a, 14b, 14c, 14d), each midpoint (13a, 13b) of the bridge (13) being connected to one of the terminals (11a, 11b) of the module (10), the electrical energy storage unit (12) being arranged in a branch in parallel with the switching arms, and at least one module (10) comprising a bidirectional switching cell arranged between its primary terminal (11a) and its secondary terminal (11b), this switching cell comprising at least one controllable semiconductor switch (15), the method comprising: - The control (210) of the at least one switch (15) of the at least one switching cell to be in the closed position, and / or - The control (211) of the switches of all the modules (10) of all the chains (30) so that the switches (14a, 14b, 14c, 14d) of the switching bridge (13) connected to the same terminal (11a, 11b) of the electrical energy storage unit (12) are controlled to be in the closed position, and the other switches are controlled to be in the open position, and - The control (212) of the switches (107) connecting the chains (30) to the phases (102x, 102y, 102z) of the motor (102) to be in the closed position. Electrical circuit (100) for powering a rotating electrical propulsion machine (102) of a vehicle comprising: - a polyphase electric machine (102), - a plurality of chains (103) of electrical modules (30), the modules (10) comprising: • a primary terminal (11a) and a secondary terminal (11b), the primary terminal (11a) being connected to the secondary terminal (11b) of another module (10) and / or the secondary terminal (11b) being connected to the primary terminal (11a) of another module (10), • an electrical energy storage unit (12), and • at least one controllable switch (14a, 14b, 14c, 14d, 15) capable of connecting or disconnecting the electrical energy storage unit (12) to the primary (11a) and secondary (11b) terminals of the module (10), - a system of switches comprising a set of switches (107) allowing for each string (30) to connect it to the terminals of a phase (102x, 102y, 102z) of the electrical machine (102) and - a control unit (109), capable of controlling the switches within the electrical circuit (100), comprising the means for implementing the method according to any one of the preceding claims.

5. Circuit (100) according to the preceding claim, the modules (10) comprising an H-shaped switching bridge (13) comprising controllable switches, each midpoint (13a, 13b) of the bridge (13) being connected to one of the terminals (11a, 11b) of the module (10), the electrical energy storage unit (12) being arranged in a branch in parallel with the switching arms.

6. Circuit (100) according to the preceding claim, the set of switches (107) of the switch system allowing for each chain (30) to connect it to a phase (102x, 102y, 102z) of the electrical machine (102) to which this chain (30) is dedicated.

7. Circuit (100) according to the preceding claim, comprising an input interface (101) capable of being connected to a charging station, the switch system comprising a second set of switches (106) allowing each chain (30) to be connected to the input interface (101).

8. Circuit (100) according to any one of claims 4 to 7, all or part of the modules (30) comprising a bidirectional switching cell arranged between their primary terminal and its secondary terminal, this switching cell comprising at least one controllable semiconductor switch (15).

9. Circuit (100) according to the preceding claim, the at least one switching cell comprising a bidirectional transistor (15), two unidirectional transistors mounted in antiparallel, or a microelectromechanical system switch.

10. Circuit (100) according to any one of claims 4 to 7, the electrical energy storage unit (12) being arranged in a branch of the module (10) devoid of switches.

11. Circuit (100) according to any one of claims 4 to 9, the voltage between the first terminal (37a) and the second terminal (37b) of a chain (30) defining the unique output voltages of said chain (30).

12. Circuit (100) according to any one of claims 4 to 8, the number of chains (30) being greater than or equal to the number of phases (102x, 102y, 102z) of the rotating electrical machine (102).

13. A computer program product, comprising instructions which cause the control unit (109) of claim 4 to implement the steps of the method according to any one of claims 1 to 7

14. 1 d J. Computer-readable medium, on which the computer program product according to the preceding claim is recorded.

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