Method for controlling a vehicle electric energy storage unit charger, and charger

Abstract

Method of controlling a charger (1) for a vehicle electrical energy storage unit, the charger (1) comprising: - a connector (3) suitable for connection to an electrical network capable of supplying a three-phase alternating voltage, - an inverter / rectifier (6), comprising a first, a second and a third switching arm (7) mounted in parallel, each switching arm (7) comprising two controllable electronic switches (8) disposed on either side of a midpoint (9) suitable for connection to a respective phase of the alternating voltage, - a fourth switching arm (10) mounted in parallel with the first, second and third switching arms (7) of the inverter / rectifier (6), this fourth switching arm (10) comprising two switches (11) disposed on either side of a fourth midpoint (12) suitable for connection to the neutral of the electrical network, and - a branch (13) mounted in parallel with said switching arms (7, 10),comprising two capacitors (14) arranged on either side of a fifth midpoint (15), a switch (21) being mounted in series between the fourth (12) and fifth (15) midpoints, the method comprising: - the determination (110) of the value of the neutral current, - the determination (111) of a control signal, so as to allow regulation of the voltage between the fifth midpoint and ground, and regulation of the neutral current, and - the determination (107) of duty cycles for the electronically controllable switches of the first, second and third switching arms on the basis of the control signal. Abbreviated figure: Fig. 2,

Description

Title of the invention: Method for controlling a vehicle electrical energy storage unit charger, and charger

[0001] The present invention relates to a method for controlling a charger for a vehicle electrical energy storage unit, and it also relates to such a charger. The electrical energy storage unit is, for example, a battery, which may have a nominal voltage greater than 60V, for example greater than or equal to 300V, 400V, 800V, or even 1000V.

[0002] The charger comprises, in a known example:

[0003] - an inverter / rectifier receiving at its input a three-phase alternating voltage of charging terminal and providing a DC output voltage, and

[0004] - a DC / DC converter disposed downstream of the inverter / rectifier and connected to the electrical energy storage unit.

[0005] Such an inverter / rectifier implements a plurality of controllable electronic switches such as MOSFET transistors or IGBTs.

[0006] It is known to control such an inverter / rectifier by controlling the phase currents and the DC voltage between the inverter / rectifier and the DC / DC converter, by varying the duty cycles applied to the three switching arms of the inverter / rectifier. The DC / DC converter is controlled to follow the power demand from the electrical energy storage unit.

[0007] Known chargers may include a fourth switching arm connected to the neutral of the electrical network. It is then necessary to control the inverter / rectifier in such a way as to ensure, as far as possible, that the sum of the phase currents is zero, in order to avoid injecting the third harmonic of the zero-sequence current into the network.

[0008] There is a need to remedy the aforementioned drawback with a solution that is simple to implement, avoiding in particular the use of additional sensors, and that is sufficiently precise.

[0009] The invention aims to meet this need and achieves this, according to one of its aspects, by means of a method for controlling a vehicle electrical energy storage unit charger, the charger comprising:

[0010] - a connector suitable for being connected to an electrical network capable of supplying a voltage three-phase alternative,

[0011] - an inverter / rectifier, comprising a first, a second and a third arm parallel-mounted switching arms, each switching arm comprising two controllable electronic switches arranged on either side of a midpoint suitable for connection to a respective phase of the alternating voltage,

[0012] - a fourth switching arm mounted in parallel with the first, second and the third switching arm of the inverter / rectifier, this fourth switching arm comprising two switches arranged on either side of a fourth midpoint suitable for connection to the neutral of the electrical network, and

[0013] - a branch mounted in parallel with said switching arms, comprising two capacitors arranged on either side of a fifth midpoint, with a switch connected in series between the fourth and fifth midpoints,

[0014] the method comprising:

[0015] - the determination of the value of the current at the neutral,

[0016] - the determination of a control signal, so as to allow: the regulation of the voltage between the fifth midpoint and ground, and the regulation of the current at neutral, and

[0017] - the determination of duty cycles for electronic switches controllable from the first, second and third switching arms based on the control signal.

[0018] The invention consists of taking into account, for controlling the first, second and third switching arms of the inverter / rectifier:

[0019] - balancing between: the voltage across one of the two capacitors of the parallel branch of the switching arms, and the voltage across the other of the two capacitors in this branch, and

[0020] - the regulation of the current at the neutral.

[0021] The value of the current at the neutral is thus reduced by regulating the value of the voltage between the fifth midpoint and ground.

[0022] Each controllable electronic switch of one of the first, second and third switching arms can be of the same type, for example IGBT transistors or MOSFET transistors.

[0023] Each electronic switch in the fourth switching arm is, for example, different from the switches in the first, second, and third switching arms. It is, for example, a diode, such as a so-called "fast time recovery" (or FTR) diode, or another type of non-controllable electronic switch. Alternatively, IGBT transistors can be used to implement the switches in the fourth switching arm.

[0024] The two capacitors of the branch mounted in parallel with the switching arms can have the same capacitance, the latter being for example between 1000 pF and 2000 pF, as will be seen later.

[0025] The presence of the fourth switching arm in parallel with the switching arms of the inverter / rectifier and whose midpoint is suitable for connection to the neutral allows this fourth switching arm to be used for single-phase rectification when the load terminal supplies a single-phase voltage.

[0026] This provides a charger that allows:

[0027] - a three-phase load via the three phases of the alternating voltage and the three arms of inverter / rectifier switching, and

[0028] - a single-phase load using the neutral of the alternating voltage and the fourth switching arm.

[0029] In all the foregoing, the fourth midpoint can be connected to an electrical conductor suitable for connection to the neutral of the electrical network, and the current flowing in this electrical conductor is the "current to the neutral" according to the invention.

[0030] The switch connected in series between the fourth and fifth midpoints is, for example, an electrotechnical relay. However, the invention is not limited to such an example; other switches are possible, for example, a solid-state relay based on optical couplers and / or MOSFET transistors and / or IGBT transistors.

[0031] The voltage regulation between the fifth midpoint and ground, and the current regulation at neutral, can be achieved through a cascade control system using two nested loops. The voltage regulation between the fifth midpoint and ground can be performed using the outer loop, and the current regulation at neutral can be performed using the inner loop.

[0032] The internal loop may include a controller, in particular a proportional-integral controller, and the method may include a substep of dynamically applying a variable saturation value when the output signal of this controller exceeds a threshold value, the control signal then taking on the saturation value. The threshold value may also be variable. In this case, the threshold value is equal to the saturation value; that is, as soon as this threshold value is reached, the output signal of the controller in the internal loop saturates at this threshold value.

[0033] If applicable, when the absolute value of the output signal of the internal loop controller reaches the threshold value, this output signal saturates at approximately this threshold value. According to one implementation example, the output signal of the internal loop controller is thus limited between two opposing values ​​that may or may not vary dynamically.

[0034] Implementing a dynamically variable saturation value applied to the output signal of the internal loop controller allows for neutral current regulation while remaining compatible with the control of the first, second, and third switching arms to convert AC current into DC current DC is used to efficiently charge the electrical energy storage unit. This prevents the output signal value of this controller from becoming so high that the control signal has an excessive influence on the duty cycle determination, which would then affect the ability of these duty cycles to convert AC current to DC current for the desired load. This prioritizes the control of the inverter / rectifier's phase currents.

[0035] Providing a dynamically evolving saturation value can allow for better adaptation to the state of the electrical network, taking into account potential voltage drops and / or harmonic issues and / or frequency variations, which can impact phase currents. When the internal loop controller is a proportional-integral controller, applying a dynamic saturation value could be considered as a feedforward signal with a voltage output in order to avoid saturation of the "integral" term of the controller.

[0036] The control signal can, in case of saturation, occupy several different values, depending on the case.

[0037] The invention is not limited to the use of a proportional-integral controller in the internal loop, a resonant proportional controller being able to be used alternatively.

[0038] The dynamic saturation value can be determined based on the value of the difference between:

[0039] - the voltage across the switching arms, and

[0040] - the magnitude of the vector obtained by mathematical transform of a three-phase system In a two-phase system, the three-phase system is representative of the phase voltages of the electrical network. The magnitude of this vector can correspond to the amplitude of the alternating voltage of the electrical network.

[0041] The mathematical transform is for example a Clarke, Concordia or Park transform.

[0042] The dynamic saturation value can be determined as being equal in absolute value to a percentage of the value of the aforementioned difference between:

[0043] - the voltage across the switching arms, and

[0044] - the magnitude of the vector obtained by mathematical transform of a three-phase system in a two-phase system, the three-phase system being representative of the phase voltages of the electrical network.

[0045] The aforementioned percentage is for example less than or equal to 10%, for example less than or equal to 5%, for example in the order of 2%.

[0046] The regulation of the voltage between the fifth midpoint and ground using the external loop can be carried out by comparing, at the input of this external loop: twice a measurement of said voltage between the fifth midpoint and ground, and the value of the voltage across the switching arms, and providing on the basis of this comparison a setpoint value for the neutral current.

[0047] The regulation of the neutral current can be carried out by comparing at the input of the internal loop: the setpoint value for the neutral current, and the value of the neutral current determined according to the method.

[0048] In all the above, the determination of duty cycles for the controllable electronic switches of the first, second and third switching arms can be carried out by combining the control signal, having where appropriate a saturation value, with control signals, for example voltages, for each switching arm.

[0049] Each duty cycle aî is obtained, for example, using the equation

[0050] n

[0051] where:

[0052] - viref is the control voltage for phase i,

[0053] - vsat is the value of the control signal, where applicable the saturation value, and

[0054] - VDC is the value of the voltage across the switching arms.

[0055] The presence of the term vsat, caused by the presence of neutral current when the electrical network is unbalanced, modifies the conventional generation of duty cycle for controlling phase currents. This prevents the injection of the 3rd harmonic of this neutral current into the network.

[0056] Determining the neutral current value may involve applying a low-pass filter to the measured phase current values. This filter may, for example, have a cutoff frequency of 10 Hz, 2 Hz, or 1 Hz. The DC component present in the phase current measurements can then be subtracted from the phase currents upstream of the low-pass filter to determine, for each phase current, a signal without a DC component. The sum of these three phase currents without a DC component can provide the current signal that will be compared at the input of the inner loop to the output signal of the outer loop. This step of determining the neutral current is thus advantageously carried out using a conventional filter.

[0057] The invention also relates, according to another aspect, to a vehicle electrical energy storage unit charger, comprising:

[0058] - a connector suitable for being plugged into an electrical network capable of supplying a voltage three-phase alternative,

[0059] - an inverter / rectifier, comprising a first, a second and a third arm parallel-mounted switching arms, each switching arm comprising two controllable electronic switches arranged on either side of a midpoint suitable for connection to a respective phase of the alternating voltage,

[0060] - a fourth switching arm mounted in parallel with the first, second and the third switching arm of the inverter / rectifier, this fourth switching arm comprising two switches arranged on either side of a fourth midpoint suitable for connection to the neutral of the electrical network, and

[0061] - a branch mounted in parallel with said switching arms, comprising two capacitors arranged on either side of a fifth midpoint, a switch being mounted in series between the fourth and fifth midpoints, and

[0062] - a control unit adapted to execute the steps of the above method.

[0063] All of the above also applies to the charger according to this other aspect of the invention.

[0064] The inverter / rectifier can be configured to perform power factor correction (PFC) of the AC voltage. The inverter / rectifier then uses, for example, the so-called "totem-pole" topology.

[0065] The charger may include a cascaded DC / DC converter with the fourth switching arm and the branch comprising the two capacitors.

[0066] This DC / DC converter includes, for example, galvanic isolation, notably via a transformer. This transformer is, for example, a single-phase or three-phase transformer. This DC / DC converter includes, in a known manner:

[0067] - a second inverter / rectifier mounted between the DC output of the previous one inverter / rectifier and the transformer primary, and

[0068] - a third rectifier / inverter or a diode rectifier, mounted between the secondary winding of the transformer and the electrical energy storage unit. When a third rectifier / inverter is present, it may include MOSFET transistors enabling synchronous rectification.

[0069] The DC / DC converter is for example a resonant converter of type LLC or CLLC.

[0070] Each capacitor in the branch connected in parallel with the switching arms is, for example, an electrolytic capacitor, having, for example, a capacitance between 100 pF and 2000 pF. These capacitors handle, for example, low-frequency currents.

[0071] In parallel with the fourth switching arm, another arm comprising only a capacitor can also be mounted. This could be, for example, a capacitor with a capacitance on the order of a few hundred nF. This capacitor is intended, in particular, to reduce high-frequency ripple. This capacitor could, for example, be made of polypropylene or ceramic.

[0072] The control unit may include a microcontroller, or an integrated circuit for example an FPGA or an ASIC.

[0073] In all the foregoing, the charger may include an AC current filtering stage arranged in series between the connector and the inverter / rectifier. This filtering stage allows, for example, when the AC voltage is polyphase, common-mode current filtering and / or differential current filtering.

[0074] In all the above, the charger may include a DC current filtering stage arranged in series between the DC / DC converter and the electrical energy storage unit.

[0075] In all the above, the network voltage may have a frequency of 50 Hz or 60 Hz and an RMS value of 230V or 240V. In all the above, the electrical energy storage unit is, for example, a battery, which may have a nominal voltage greater than 60V, for example greater than or equal to 300V, 400V, 800V, or even 1000V.

[0076] In all the above, the charger can enable the electrical energy storage unit to be charged with a power of 7kW, 11kW or 22kW, or even more.

[0077] The charger may or may not be housed in the same casing with a DC / DC converter that performs voltage conversion between the voltage across the electrical energy storage unit, referred to as "high voltage," and the voltage of the vehicle's electrical system, referred to as "low voltage." As already mentioned, high voltage is, for example, greater than 60V, for example greater than or equal to 300V, 400V, 800V, or even 1000V, while low voltage is, for example, equal to 12V or 48V.

[0078] The invention also relates, according to yet another aspect, to a computer program product comprising instructions which lead the above loader to execute the steps of the above method.

[0079] The invention also relates, according to yet another aspect, to a computer-readable medium on which the above-mentioned computer program is recorded. For the purposes of this application, the computer capable of reading the computer program is, for example, the aforementioned control unit, possibly via its microcontroller, or its integrated circuit such as an FPGA or an ASIC.

[0080] In all of the above, the charger may or may not be reversible. A reversible charger then allows the transfer of electrical energy from the electrical energy storage unit to the electrical grid or to a load connected to the charger's connector.

[0081] The invention will be better understood upon reading the following description of a non-limiting example of its implementation and upon examination of the accompanying drawing in which:

[0082] - [Fig. 1] represents a charger in which an example of a method of The order according to the invention can be implemented,

[0083] - [Fig.2] is a view similar to [Fig.1] in which the steps of the method of commands are represented by block diagrams.

[0084] - [Fig.3] represents in isolation one of the steps of the control method,

[0085] - [Fig.4] represents in isolation another step of the control method,

[0086] - [Fig.5] is a different representation of [Fig.2], and

[0087] - [Fig.6] and [Fig.7] represent examples of correctors that can be used for the internal loop and the external loop implemented in an example of a control method.

[0088] Figure 1 shows an example of a charger 2 for an electrical energy storage unit from an electrical network 1. The electrical energy storage unit is a battery used to power an electric vehicle propulsion machine. This battery has, for example, a nominal voltage greater than 60V, in particular 300V, in particular 400V, in particular 800V, or even 1000V.

[0089] The electrical network 1 is, for example, a three-phase network carrying a voltage at a first frequency of 50 Hz or 60 Hz and with an RMS value of 230 V or 240 V. The electrical network 1 is connected to the charger via a connector 3 shown schematically in [Fig. 1]. This connector 3 includes, for example, four contacts for connection to the electrical network, namely one contact per phase and one contact for the neutral.

[0090] Charger 2 comprises, in this example:

[0091] - an inverter / rectifier 6, comprising three switching arms 7 mounted in parallel, each switching arm 7 comprising two controllable electronic switches 8 arranged on either side of a midpoint 9 suitable for connection to a respective phase of the alternating voltage of the electrical network 1,

[0092] - a fourth switching arm 10 mounted in parallel with the switching arms 7, this fourth switching arm 10 comprising two switches 11 arranged on either side of a fourth midpoint 12 suitable for connection to the neutral of the electrical network, and

[0093] - a branch 13 mounted in parallel with said switching arms 7 and 10, comprising two capacitors 14 arranged on either side of a fifth midpoint 15.

[0094] All the switches 8 here are MOSFET or IGBT transistors, and all the switches 11 here are FTR diodes.

[0095] Each midpoint 9 of one of the first, second and third switching arms 7 can be connected to an inductance 5, so as to form a so-called "totem pole" assembly.

[0096] It can be seen that the branch 13 and the switching arms 7 and 10 are mounted between two DC terminals. It can also be seen in the example considered that the fourth midpoint 12 is connected to the fifth midpoint 15 via a switch 21. The switch 21 is in this case an electrotechnical relay. Alternatively, other examples are possible, for example, the use of solid-state relays based on optical couplers and / or MOSFET transistors and / or IGBT transistors.

[0097] The charger 2 further comprises, in the example of [Fig. 1], a DC / DC converter 25, which is represented here in a very schematic manner. This DC / DC converter may, in a known manner, comprise two DC / AC converters, in particular reversible ones, and a galvanic isolation transformer arranged between these two DC / AC converters. The DC / DC converter is, for example, resonant, being of the LLC or CLLC type, among others.

[0098] As shown in [Fig. 1], an alternating current filtering stage 35 may be provided, this filtering stage 35 being arranged in series between connector 3 and the inverter / rectifier 6. This filtering stage 35 allows, in particular in the present case of a polyphase alternating voltage, common-mode current filtering and / or differential current filtering. If necessary, and although not shown in the figures, another direct current filtering stage may be present, being then arranged in series between the DC / DC converter 25 and the electrical energy storage unit.

[0099] The charger 2 includes a control unit 40, the role of which will be described below. This control unit 40 is, for example, implemented using several modules. This control unit 40 includes, for example, microcontrollers and / or integrated circuits. This control unit 40 can, as shown with reference to [Fig. 2], control the inverter / rectifier 6 so as to rectify the three-phase current received from the electrical network 1 while ensuring power factor correction (PFC).

[0100] This command can implement the following steps in a known manner:

[0101] - in 100: acquisition of the phase currents ia, ib and ic at the level of each inductance 5, and application to these currents of a Park transform,

[0102] - in 101: acquisition of the voltage VDc across the terminals of the switching arms 7 and 10,

[0103] - in 102: implementation of a voltage control loop to regulate the voltage acquired in 101,

[0104] - in 103: acquisition of the phase voltages va, vb and vc of network 1, and of the voltage and of the current from the electrical energy storage unit, and application to the phase voltages of the Park transform,

[0105] - in 104: calculation of a setpoint current for phase currents by taking into account takes into account the power balancing between the inverter / rectifier 6 and the DC / DC converter 25,

[0106] - in 105: realization of a phase-controlled loop for phase voltages, by Calculation of the angle used to define the setpoint for phase currents in order to synchronize the current and voltage for each phase as part of power factor improvement.

[0107] - in 106: implementation of a phase current control loop and reactive power compensation, this control loop for example implementing an inverse Park transform to calculate the setpoints for phase currents, and

[0108] - in 107: generation of duty cycles for the first 8 switches, second and third switching arms 7 of the inverter / rectifier 6.

[0109] The preceding steps are known, for example, from the IEEE publication "Operation Modes for the Electric Vehicle in Smart Grids and Smart Homes: Present and Proposed Modes" (https: / / ieeexplore.ieee.org / document / 7273953)

[0110] According to the invention, and as will now be described with reference to Figures 2 to 7, the control implemented by the control unit 40 also allows:

[0111] - according to step 110: determining the value of the neutral current, and

[0112] - according to step 111: the determination of a control signal, so as to allow voltage regulation between the fifth midpoint 15 and ground, and current regulation at neutral.

[0113] The determination of duty cycles in 107 is then carried out by also taking into account the control signal at the end of step 111. Thus, the control of the switches 8 of the switching arms 7 allows the regulation of the voltage between the fifth midpoint 15 and ground, and the reduction of the current at the neutral.

[0114] We can thus:

[0115] - to have a balance between the voltage across one of the two capacitors 14 of branch 13 and the voltage across the other of the two capacitors 14 of this branch 13, and

[0116] - reduce, or even eliminate, the third harmonic of the current at neutral.

[0117] We will now describe steps 110 and 111 in more detail with reference to figures 3 to 7.

[0118] According to a substep 120, a hardware filter is applied to the current measurements obtained at 100. According to a substep 121, a low-pass filter is applied to the current measurements resulting from substep 120. This low-pass filter has, for example, a cutoff frequency of 1 Hz or 2 Hz, and the DC component present in the phase current measurements is recovered at the output of this filter.

[0119] According to a substep 122, for each phase current measurement upstream of substep 120, the DC component present for that phase current measurement obtained at the end of substep 121 is subtracted.

[0120] Finally, according to a substep 123, the signal obtained at the end of substep 122 is added over all phases. This gives a signal representative of the current at the neutral.

[0121] We will now describe, with reference to figures 4 and 5, step 111. This step 111 implements a cascade regulation with two nested loops.

[0122] According to a substep 130, the voltage between the fifth midpoint 15 and ground is regulated using an external loop comparing at its input:

[0123] - twice a measurement of the voltage between the fifth midpoint 15 and ground, this measurement being provided, for example, by an additional sensor or estimated by an estimator, and

[0124] - the value of the VDC voltage across the switching arms 7 and 10, acquired according to 101.

[0125] The external loop according to this substep 130 implements, for example, a proportional-integral controller such as that shown in [Fig. 6]. A fixed-value saturation can be applied to the signal from this proportional-integral controller.

[0126] At the end of this substep 130, a setpoint value for the neutral current is then obtained.

[0127] According to a substep 131, the neutral current is regulated so as to reduce it and prevent the propagation of the third harmonic of this neutral current in the electrical network 1, using an internal loop comparing at its input:

[0128] - the setpoint value for the neutral current obtained at the end of the sub-step 130, and

[0129] - the value of the signal representing the neutral current obtained at the end of the step 110.

[0130] The internal loop according to this substep 131 implements for example a proportional-integral controller such as that shown in [Fig.7].

[0131] At the end of this substep 131, we obtain at the output a voltage signal regulating the current at the neutral.

[0132] Step 111 here includes yet another additional substep 132 of dynamic application of a variable saturation value when the output value of the corrector exceeds a threshold value, the control signal then taking the saturation value.

[0133]

[0134]

[0135]

[0136]

[0137]

[0138] In substep 132, the absolute value of the signal output from the controller is compared with a threshold value. If the value of the signal output from the controller is less than the threshold value, it is retained as is at the end of substep 132 and constitutes the value of the control signal used in step 107, modified according to the invention. If the absolute value of the signal output from the controller reaches the threshold value, it saturates at this threshold value, either positive or negative, in the example considered, and this dynamically determined saturated value then constitutes the value of the control signal applied in step 107, modified according to the invention. The threshold value, which is the saturation value in this example, is determined to be equal to a percentage of the difference between: - the VDC voltage across the switching arms 7, 10, and - the magnitude of the vector obtained by mathematically transforming the three-phase system formed by the phase voltages of the electrical network into a two-phase system. This magnitude corresponds here to the amplitude of the alternating voltage of the electrical network. The mathematical transform is, for example, the Park transform, which is applied in 103 to the phase voltages va, vb, and vc, as already mentioned above. As is known, the magnitude of the vector [va, v[3] obtained using the aforementioned Park transform is equal to + v2 • At the output of substep 132, the value of the signal at the output of the corrector at the end of substep 131 is thus limited between -M times the aforementioned difference and +M times this difference.

[0139] By way of example, considering:

[0140] - a value of 2% for M,

[0141] - an effective value voltage of 230V for each phase voltage,

[0142] - a value of 700V for the VDC voltage across the terminals of the switching arms 7, 10,

[0143] The values ​​of -7.5V and +7.5V are obtained as the limits for the variation of the signal at the end of substep 132. Saturation is applied dynamically.

[0144] The signal at the end of this substep 132 is then taken into account during step 107 to determine the duty cycles to be applied to each switching arm 7 according to the following equation, for each phase i:

[0145] [Math2] W^+0.5 * VDC

[0146] where:

[0147] - viref is the control voltage for phase i as generated during step 106 in which the inverse Park transform is applied to a two-component control voltage vector,

[0148] - vsat is the value of the control signal at the end of substep 132, if applicable with a saturation value.

[0149] Still with the numerical example above, a value of vsat equal to 7.5V corresponds to a duty cycle value deviation of 0.01 compared to the duty cycle value in step 107 according to the prior art.

[0150] Of course, if the values ​​of the phase voltages and the VDC voltage across the switching arms 7, 10 change, for example due to the state of the electrical network, the saturation value and the duty cycle deviation will vary dynamically.

[0151] The invention is not limited to the example just described.

[0152] Where appropriate, a saturation value is also dynamically applied to the output signal of the external loop corrector at the end of substep 130.

Claims

Demands

1. Method of controlling a charger (1) for a vehicle electrical energy storage unit, the charger (1) comprising: - a connector (3) suitable for connection to an electrical network capable of supplying a three-phase alternating voltage, - an inverter / rectifier (6), comprising a first, a second and a third switching arm (7) mounted in parallel, each switching arm (7) comprising two controllable electronic switches (8) disposed on either side of a midpoint (9) suitable for connection to a respective phase of the alternating voltage, - a fourth switching arm (10) mounted in parallel with the first, second and third switching arms (7) of the inverter / rectifier (6), this fourth switching arm (10) comprising two switches (11) disposed on either side of a fourth midpoint (12) suitable for connection to the neutral of the electrical network,and - a branch (13) mounted in parallel with said switching arms (7, 10), comprising two capacitors (14) arranged on either side of a fifth midpoint (15), a switch (21) being mounted in series between the fourth (12) and fifth (15) midpoints, the method comprising: - the determination (110) of the value of the neutral current, - the determination (111) of a control signal, so as to allow regulation of the voltage between the fifth midpoint and ground, and regulation of the neutral current, and - the determination (107) of duty cycles for the controllable electronic switches (8) of the first, second and third switching arms (7) on the basis of the control signal.

2. Method according to claim 1, wherein the regulation of the voltage between the fifth midpoint (15) and ground, and the regulation of the current at the neutral is a cascade regulation implementing two nested loops, and wherein the voltage between the fifth midpoint (15) and ground is regulated (130) using the outer loop, and wherein the current at the neutral is regulated (131) using the inner loop.

3. Method according to claim 2, the inner loop comprising a controller, in particular a proportional-integral controller, and the method comprising a substep (132) of dynamically applying a variable saturation value when the output value of this controller exceeds a threshold value, the control signal then taking the saturation value.

4. Method according to claim 3, the threshold value being equal to the saturation value.

5. Method according to claim 3 or 4, the saturation value being determined dynamically as a function of the value of the difference between: - the voltage (VDC) across the switching arms (7, 10), and - the magnitude of the vector obtained by mathematical transformation of a three-phase system into a two-phase system, the three-phase system being representative of the phase voltages of the electrical network (1).

6. Method according to any one of claims 2 to 5, the regulation of the voltage between the fifth midpoint (15) and ground using the external loop being carried out by comparing at the input of this external loop: twice a measurement of said voltage between the fifth midpoint (15) and ground, and the value of the voltage across the switching arms (7, 10), and providing on the basis of this comparison a setpoint value for the neutral current.

7. Method according to claim 6, the regulation of the neutral current being carried out by comparing at the input of the internal loop: the setpoint value for the neutral current, and the determined value of the neutral current.

8. A method according to any one of the preceding claims, wherein the determination of duty cycles for the controllable electronic switches (8) of the first, second and third switching arms (7) is carried out by combining the control signal, having optionally a saturation value, with control signals for each switching arm (7).

9. A method according to any one of the preceding claims, wherein the determination of the value of the neutral current includes the application to the measured phase current values ​​of a low-pass filter.

10. A vehicle electrical energy storage unit charger (1), comprising: - a connector (3) suitable for connection to an electrical network capable of supplying a three-phase alternating voltage, - an inverter / rectifier (6), comprising a first, a second and a third switching arm (7) mounted in parallel, each switching arm (7) comprising two controllable electronic switches (8) disposed on either side of a midpoint (9) suitable for connection to a respective phase of the alternating voltage, - a fourth switching arm (10) mounted in parallel with the first, second and third switching arms (7) of the inverter / rectifier (6), this fourth switching arm (10) comprising two switches (11) disposed on either side of a fourth midpoint (12) suitable for connection to the neutral of the electrical network, and - a branch (13) mounted in parallel with said switching arms (7, 10),comprising two capacitors (14) arranged on either side of a fifth midpoint (15), a switch (21) being mounted in series between the fourth (12) and fifth (15) midpoints, and - a control unit (40) adapted to perform the steps of the method according to any one of the preceding claims.

11. Product computer program comprising instructions that direct the loader (1) according to claim 10 to execute the steps of the method according to any one of claims 1 to Q

12. y. Computer-readable medium on which the computer program according to claim 11 is recorded.

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