Method for controlling a three-phase Vienna rectifier in the event of a power switch failure

Abstract

The invention relates to a method for controlling a three-phase Vienna rectifier (20) comprising three switching arms (1, 2, 3), each switching arm being associated with an electrical phase (a, b, c), each switching arm (1, 2, 3) comprising a high controlled power switch (M1H, M2H, M3H) connected in series and oppositely to a low controlled power switch (M1L, M2L, M3L); when the switching arm comprises a faulty switch (M2H, M2L), the method comprising: - the step of calculating the duty cycle of the high controlled switch and the low controlled switch to be applied to the two active arms according to the received voltage value (V13) between the two active arms and according to the measured DC voltage value (VDC) so that no current flows through the faulty switching arm (2).

Description

Technical Field

[0001] The invention relates to a method for controlling a three-phase Vienna rectifier for a charging device having a three-phase input in the event of a power switch failure of the Vienna rectifier. Background Art

[0002] Such a charging device is particularly suitable for use as an on-board device in an electric vehicle or a hybrid vehicle.

[0003] These vehicles are equipped with a high voltage battery and usually include an on-board charger, i.e. a device mounted directly on the vehicle for charging the battery. The main function of these charging devices is to recharge the battery using the electricity available on the power distribution network. The desired criteria for charging devices, especially for on-board chargers, are high efficiency, small overall size, electrical isolation, high reliability, operational safety, low electromagnetic interference emissions, and low input current harmonic levels.

[0004] Here, we focus on the category of charging devices with three-phase input, which have higher charging power than charging devices with single-phase input. Figure 1 A known topology of an isolated charging device 10 mounted on an electric or hybrid vehicle for recharging a high-voltage battery of the vehicle using a three-phase electrical network 30 is shown, to which the on-board charging device 10 is connected via a line impedance 40 of the network.

[0005] For the purpose of implementing an AC-DC conversion function with electrical isolation, it is known to use a charging device 10 comprising a first AC-DC converter including a power factor correction (or "PFC", "Power Factor Correction") circuit 20 to limit input current harmonics and a second DC-DC (direct current to direct current) converter 12 for regulating the load and for providing an isolation function for safe use. An input filter 13 is conventionally incorporated at the input of the on-board charging device 10, upstream of the PFC circuit 20 relative to the three-phase power grid 30.

[0006] The PFC circuit 20 is controlled by an integrated controller (not shown) which analyses and corrects in real time the behaviour of the current relative to the voltage. From this, it derives waveform errors by comparison with the rectified sine of the voltage and corrects these waveform errors by controlling the amount of energy generated due to high frequency cut-off and the energy storage in the inductor. More precisely, its function is to obtain a current at the mains input of the charger that is non-phase-shifted and as sinusoidal as possible.

[0007] For the PFC circuit 20, it is known to implement a three-level three-phase rectifier with three switches, which is generally referred to as a three-phase Vienna rectifier, as disclosed in the prior art documents CN 104811061, EP 94120245 and Figure 2 Described in .

[0008] The choice of this topology is particularly advantageous with regard to the performance of power factor correction.

[0009] In the three-phase Vienna rectifier 20 , each phase of the three-phase AC input voltage 30 is connected to the switching arms 1 , 2 , 3 of the rectifier 20 , which are respectively provided with power switching units M1 , M2 , M3 , through corresponding inductors La, Lb, Lc.

[0010] The power switch units M1, M2, M3 are respectively placed between the corresponding inductors La, Lb, Lc and a midpoint O, which is located between the two output voltages V of the rectifier 20. DCH With V DCL The two output voltages correspond to the voltage on the first output capacitor C1 connected between the midpoint O and the positive power supply line H, and the voltage on the second output capacitor C2 connected between the midpoint O and the negative power supply line L, respectively.

[0011] Typically, to control such a Vienna rectifier 20, the voltage and current ia, ib, ic are measured upstream of the inductors La, Lb, Lc or alternatively downstream and also at the output of the rectifier 20, and a control loop is used to generate the duty cycle required to adjust the average on-time of the switches M1, M2, M3.

[0012] In this specification, for simplicity, the term “unit M1 ” and the term “switch M1 ” are used in an equivalent manner, but formally, the unit M1 includes a high switch M1H and a low switch M1L.

[0013] In the prior art, the duty cycle is applied to each switching arm of a three-phase Vienna rectifier by using one or the other of the two switches depending on the direction of current flow in the arm.

[0014] However, when the switch of a switching arm becomes faulty and blocked in the closed position, it can no longer be controlled and therefore can no longer provide the desired sinusoidal current.

[0015] In order to overcome the problem of faulty components in Vienna rectifiers, there is known document US 9293909, in which an additional system enables the faulty component to be disconnected from the system so that a spare component can be connected. However, this solution does not provide for the continuous operation of the charger in the event of a fault, since a replacement operation is required. This also requires the presence of a spare component, resulting in additional costs for the charger.

[0016] Therefore, there is a need for a control system for a three-phase Vienna rectifier in the event of a switch failure in a switching arm, which control system can provide continued operation of the Vienna rectifier. Summary of the invention

[0017] A method for controlling a three-phase Vienna rectifier comprising three switching arms, each switching arm being associated with an electrical phase, each switching arm comprising a high controlled power switch mounted in series and opposite to a low controlled power switch; when a switching arm comprises a faulty switch blocked in an open state, the method comprises:

[0018] - a step of identifying the faulty switch arm comprising said faulty switch and the other two functional arms;

[0019] - a step of receiving a control voltage value corresponding to the voltage value to be applied between the two active arms;

[0020] - Output DC voltage (V DC ) is maintained at a value greater than the voltage difference between two electrical phases at the input terminal of the three-phase Vienna rectifier;

[0021] - a step of receiving a measured DC voltage value;

[0022] - a step of calculating the duty cycle of the high controlled switch and the low controlled switch to be applied to the two active arms as a function of said received voltage value and said measured DC voltage between the two active arms; and

[0023] - A control step comprising applying the calculated duty cycle to the three-phase Vienna rectifier, wherein the conductive switch of the intermediate voltage phase remains closed during a time interval when the phase comprising the fault switch provides a path conducive to current flow during this time interval.

[0024] Thus, even in the event of a failure of one or both controlled switches of a switching arm, the operation of the three-phase Vienna rectifier in the battery charger can be ensured without adding auxiliary components.

[0025] In other words, the availability of the charging system can be increased without adding any auxiliary components, and the vehicle can be recharged from the three-phase grid even in the event of a switch failure of a switching arm.

[0026] In particular, the duty cycle to be applied to the high controlled switch and the low controlled switch is based on a comparison of the voltage value of the phase associated with the faulty switch arm with a first phase voltage value and with a second phase voltage value, wherein the first phase voltage value corresponds to the phase associated with the first active arm and the second phase voltage value corresponds to the phase associated with the second active arm.

[0027] The duty cycle is therefore simply calculated from the phase voltage measurements which are relatively simply performed.

[0028] In particular, when the voltage value of the phase associated with the faulty switching arm is between the first voltage value and the second voltage value, the duty cycles are simultaneously applied to the high switch of the first functional arm and the low switch of the second functional arm, the duty cycle being equal to 1 minus the ratio between the received voltage and twice the measured DC voltage, such that α 1H =α 3L =1-V 13 / (2*V DC ).

[0029] In particular, when the voltage value of the phase associated with the faulty switching arm is greater than the first phase voltage value and the second phase voltage value, and

[0030] When the voltage difference between the first phase voltage value and the second phase voltage value has the same sign as the control voltage value,

[0031] A duty cycle is then applied to the low switch of the second active arm, this duty cycle being calculated so that it is equal to 1 minus the ratio between the control voltage and the measured DC voltage, such that:

[0032] α 3L =1-V 13 / V DC ,

[0033] The high switch of the first acting arm remains closed.

[0034] In particular, when the voltage value of the phase associated with the faulty switching arm is greater than the first phase voltage value and the second phase voltage value, and

[0035] When the voltage difference between the first phase voltage value and the second phase voltage value has an opposite sign to the control voltage value,

[0036] A duty cycle is then applied to the low switch of the first active arm, this duty cycle being calculated so that it is equal to 1 plus the ratio between the received voltage and the measured DC voltage, such that:

[0037] α 1L =1+V 13 / V DC ,

[0038] The high switch of the second active arm remains closed.

[0039] In particular, when the voltage value of the phase associated with the faulty switching arm is less than the first phase voltage value and the second phase voltage value, and

[0040] When the voltage difference between the first phase voltage value and the second phase voltage value has the same sign as the control voltage value,

[0041] A duty cycle is then applied to the high switch of the first active arm, this duty cycle being calculated such that it is equal to 1 minus the ratio between the received voltage and the measured DC voltage, such that:

[0042] α 1H =1-V 13 / V DC ,

[0043] The low switch of the second active arm remains closed.

[0044] In particular, when the voltage value of the phase associated with the faulty switching arm is less than the first phase voltage value and the second phase voltage value, and

[0045] When the voltage difference between the first phase voltage value and the second phase voltage value has an opposite sign to the control voltage value,

[0046] A duty cycle is then applied to the high switch of the second active arm, this duty cycle being calculated so that it is equal to 1 plus the ratio between the received voltage and the measured DC voltage, such that:

[0047] α 3H =1+V 13 / V DC ;

[0048] The low switch of the first active arm remains closed.

[0049] The invention also relates to a device for controlling a three-phase Vienna rectifier comprising three switching arms, each switching arm being associated with an electrical phase, each switching arm comprising a high controlled power switch mounted in series and opposite to a low controlled power switch; the device comprising:

[0050] - means for identifying a faulty switch arm comprising a faulty switch and the other two functional arms;

[0051] - means for receiving a control voltage value;

[0052] - means for receiving a measured DC voltage value;

[0053] - means for calculating the duty cycle of the high controlled switch and the low controlled switch to be applied to the two functional arms as a function of said received voltage value and said measured DC voltage between the two functional arms in such a way that no current flows through the faulty switching arm; and

[0054] - means for controlling the application of the calculated duty cycle to the three-phase Vienna rectifier.

[0055] The invention also relates to a battery charger designed to be connected to a three-phase power grid, the battery charger comprising: a line impedance designed to be connected to the three-phase power grid, a first AC-DC converter comprising a three-phase Vienna rectifier, a second DC-DC converter connected to a battery pack, and a device for controlling the three-phase Vienna rectifier as described above.

[0056] The invention also relates to a motor vehicle comprising a battery charger as described above. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] Other characteristics and advantages of the present invention will become apparent from a perusal of the following description of specific embodiments of the invention, which are provided for guidance only and are not intended to be limiting, with reference to the accompanying drawings, in which:

[0058] - Figure 1 is a schematic diagram of a battery charger according to an embodiment of the present invention;

[0059] - Figure 2 is a schematic diagram of a three-phase Vienna rectifier known in the prior art;

[0060] - Figure 3 is through according to Figure 2 Representation of the phase voltage of a three-phase Vienna rectifier. DETAILED DESCRIPTION

[0061] A battery charger designed to be connected to a three-phase power grid, for example in an electric or hybrid vehicle, comprises a power factor correction stage including a three-phase Vienna rectifier 20 .

[0062] Figure 2 The structure of a three-phase Vienna rectifier 20 known in the prior art as used in the present invention is shown.

[0063] The three-phase Vienna rectifier 2 includes three parallel input connections, each of which is coupled to one phase of the three-phase power supply grid 30 via a series of inductance coils La, Lb, Lc, and each is connected to a pair of switches M1, M2, M3 forming a first switching arm 1, a second switching arm 2 and a third switching arm 3 of the three-phase Vienna rectifier 20.

[0064] Each pair of switches M1, M2, M3 comprises a head-to-tail series assembly (also referred to as an inverse assembly) consisting of a first corresponding switch M1 which operates when the corresponding input current ia, ib, ic is positive. 1H 、M 2H 、M 3H (called high switch M 1H 、M 2H 、M 3H ) and a second corresponding switch M operating when the corresponding input current is negative 1L 、M 2L 、M 3L (called low switch M 1L 、M 2L 、M 3L ). In other words, a single switch operating on the switch branch is used for current chopping. These switches are formed by semiconductor components whose closing and opening are controlled, such as SiC-MOS (silicon carbide-metal oxide semiconductor) transistors connected in antiparallel with diodes. This type of semiconductor is suitable for very high switching frequencies. Switch M 1H 、M 2H、 M 3H Also known as high switch, and switch M 1L 、M 2L 、M 3L It is called low switch.

[0065] The three-phase Vienna rectifier 20 further comprises three parallel branches 1', 2', 3', each of which comprises two diodes D 1H and D 1L , D 2H and D 2L and D 3H and D 3L , which form a six-diode three-phase bridge, thereby allowing a unidirectional energy transfer and enabling the current and voltage taken from the three-phase power supply grid 30 to be rectified.

[0066] Each input of the three-phase Vienna rectifier 20 is connected via a corresponding parallel input connection to a connection point between two diodes in the same parallel branch 1 ′, 2 ′, 3 ′.

[0067] The two shared ends of the parallel branches 1 ′, 2 ′, 3 ′ form two output terminals H and L, which are respectively the positive output terminal and the negative output terminal of the three-phase Vienna rectifier 20 , which are designed to be coupled to the DC-DC device 12 .

[0068] The switch arms 1, 2, 3 of each phase are also connected to the connection points Xa, Xb, Xc between the two diodes of the first branch 1, the second branch 2 and the third branch 3 and the output voltage V of the three-phase Vienna rectifier 20, respectively. DCH and V DCL These output voltages correspond to the voltage on the output capacitor C1 between the positive output terminals H of the rectifier and the voltage on the output capacitor C2 between the midpoint O and the negative output terminal L of the three-phase rectifier 20, respectively.

[0069] according to Figure 1 In the overall topology shown, the voltages on the output capacitors C1 and C2 are independently controlled by the DC-DC converter of the charging device connected at the output of the three-phase Vienna rectifier 20. In other words, the output voltage of the three-phase Vienna rectifier 20 is controlled by the DC-DC converter 12.

[0070] The three-phase Vienna rectifier 20 interleaved with the power input of the charger 10 has a power factor correction function for the charger. This function prevents interference currents (harmonics) generated by the charger from flowing through the impedance of the power grid located upstream of the Vienna rectifier 20.

[0071] The switching arms 1, 2, 3 of each phase a, b, c of the three-phase grid 30 are controlled by means of six PWM (from the English “Pulse Width Modulation”) control signals with a variable duty cycle and a fixed switching frequency equal to 140 kHz, which are controlled by a control device of the three-phase Vienna rectifier (20) (for example, an FPGA-type component for high sampling frequencies).

[0072] Therefore, the control device is adapted to determine the duty cycles of the switching commands of the switches of the switching arms of the rectifier, which duty cycles are needed to control the sinusoidal current at the input of the rectifier.

[0073] However, when a power switch of the Vienna rectifier fails, the switching arms 1, 2, 3 are unavailable due to the risk of causing other damages such as short circuits.

[0074] However, in order to ensure operation of the charger even in the event of a power switch failure, the control device is adapted to implement a method of controlling in a degraded mode.

[0075] The object of the invention is therefore to ensure that the operation of the Vienna rectifier can be maintained in the event that the switching arms 1, 2, 3 become unavailable due to one or both of their control switches. Thus, it is possible to indicate to the user that there is a problem in the battery charger while enabling the user to recharge the battery in a degraded mode before carrying out repairs. In particular, in the case of a car, if the charger becomes faulty in the sense of the invention, the user can at least partially recharge his vehicle in order to drive to a car repair shop for repairs.

[0076] The control method comprises the step of identifying a faulty switch arm including the faulty switch and the other two functional arms.

[0077] For this purpose, an electrical diagnostic device (not shown) is implemented in the control card of the Vienna rectifier in order to detect whether the control switch of the Vienna rectifier 20 is blocked. Such a diagnostic device is not the subject of the present invention and is known to the person skilled in the art. Thus, such a diagnostic device makes it possible to detect a switch failure and thus also to identify fully functional switching arms 1, 2, 3.

[0078] Then the voltage value (V 13 ) steps.

[0079] Also performed is receiving a measured DC voltage value (V DC ) steps.

[0080] From these measurements and the measurements of the electrical phase voltages a, b, c associated with the switching legs 1, 2, 3, the duty cycles of the high and low controlled switches to be applied to the two active legs are calculated.

[0081] To explain this step of calculating the duty cycle, we consider an example where the switch of the second switching leg 2 fails. Hence, the switching leg 2 of phase b fails. Hence, the switching legs 1, 3 associated with phase a and phase c, respectively, are the functional legs.

[0082] Obviously, the present invention is not limited to this case, and its replacement to another faulty switching arm is exactly the same as this example, so that the method can be performed regardless of the faulty switching arm.

[0083] Therefore, the purpose is to control the current flowing through the Vienna rectifier 20 when one element is blocked. In the topology of this charger, the arm blocked in the off state does not prevent the current from flowing in the diode connected to this arm. For example, in the case where the switches M2H and M2L are blocked in the off state, the current can still flow in the diode D1H or D1L according to the voltage between each phase.

[0084] Therefore, it is necessary to create a command that includes such a constraint that a path that is favorable for current to flow in the arm with the faulty element will never be created.

[0085] In this embodiment example, one or both switches of the switch arm 2 are blocked in the open state. In both cases, charging needs to be performed with both switches of the arm 2 set in the open state.

[0086] In order to charge correctly using only arms 1 and 3, we will have to apply what is called a control voltage, V 13 The voltage V 13 , which corresponds to the target voltage between the two active switching arms 1 , 3 obtained from the control algorithm.

[0087] Control voltage V 13 is a positive voltage. However, if a negative voltage V 13 , a person skilled in the art can easily perform a transposition of the description of this example of embodiment, for example by reversing the two active arms 1 and 3 in the following description.

[0088] This method of application allows for the fact that there is a voltage between arms 1 and 2 and between arms 3 and 2 .

[0089] refer to Figure 3 , the method for calculating the duty cycle then takes into account three different cases, which are related to the phase voltage values ​​va, vb, vc, which correspond to the voltages of the switching arms 1, 2, 3: the voltage of the faulty arm 2 may be the highest, as in the range C3 and C4; it may be the lowest, as in the range C6 and C1; or the voltage of the faulty arm 2 may be in the middle, as in the range C2 and C5.

[0090] In the case of an intermediate voltage (such as Figure 3 In the range C2 and C5 in FIG1 ), where the voltage on phase b associated with the faulty switching arm 2 is between the voltages of the functional arms, a duty cycle calculated according to the following equation is then applied by simultaneous commands:

[0091] α 1H =α 3L =1-V 13 / (2*V DC )

[0092] Among them, α 1H and α 3L are respectively the high switch M to be applied to the first active arm 1 1H and the low switch M of the second active arm 3 3L Duty cycle;

[0093] V13 is the control voltage, and

[0094] V DC is the measured DC voltage value.

[0095] This is because in this intermediate case, the faulty switch arm 2 has a voltage between the voltages of the two functional switch arms 1 and 3. Therefore, the faulty arm 2 does not provide any path conducive to current flow (current always flows from the highest voltage and returns to the lowest voltage). The same argument applies when only M1H is closed or only M3L is closed. When the entire set of switches is open, there is no longer any current path and the inductor discharges.

[0096] In the highest voltage case, where the voltage on phase b associated with the faulty switching leg 2 is greater than the voltage of the functional legs 1 and 3, then two sub-cases are considered:

[0097] - In range C3, the phase voltage V of the first active arm 1 a Greater than the phase voltage V of the second active arm 3 c , and therefore the first phase voltage value V a and the second phase voltage value V c The voltage difference between V a -V c With control voltage value V 13 the same symbol; and

[0098] - In range C4, the phase voltage va of the first active arm 1 is less than the phase voltage vc of the second active arm 3, and therefore the first phase voltage value V a and the second phase voltage value V c The voltage difference between V a -V c With control voltage value V 13 Opposite signs.

[0099] In the case of range C3, the goal is to obtain a positive current i1 in the first active arm 1, since the desired sign of i1 is consistent with the control voltage V 13 same.

[0100] To ensure that switch leg 2 does not draw current, the first active leg 1 with the highest phase voltage must provide a more favorable current path than phase 2 (assuming that the switch of phase 2 is blocked in the open state). Since the voltage of phase 2 is higher than that of phase 1, switch M1H must not be opened; otherwise, current will flow from phase 2, whose voltage is higher.

[0101] Furthermore, with switch M1H closed, the path through the first active arm 1 will only be favorable if, throughout the range C3, VDC must be greater than V2-V1 (also written as V 21 ).

[0102] In range C3, the peak-to-peak amplitude is V R The maximum value of V2-V1 in a grid is equal to 1.5*Vr, that is, 487V in a typical European three-phase grid rated at 230Vrms phase-to-neutral.

[0103] Therefore, to ensure that the system remains controllable, V DC must be at least equal to this voltage threshold, to which a margin may be added in order to ensure a voltage Vdc of 500V.

[0104] Under nominal operation, the voltage Vdc is set to 450 V, making it relatively similar to the value suggested for degraded mode.

[0105] It should be noted that for the entire example of embodiment, and regardless of the range or portion of the cycle considered, a voltage Vdc of 500 V is applied.

[0106] Therefore, in range C3, the control duty cycle α of switch M3L is 3L The calculation is as follows:

[0107] α 3L =1-V 13 / (V DC );

[0108] And the high switch M of the first active arm 1 1H remains permanently closed, so the duty cycle α 1H =1.

[0109] In the second sub-case, in range C4, by similar arguments, but reversing the order of the two active arms 1 and 3, the control duty cycle will be:

[0110] α 1L =1-V 31 / (V DC )

[0111] It can also be written as:

[0112] α 1L =1+V 13 / (V DC );

[0113] Then, the high switch M3H of the second active arm is closed in the entire range C4, so that the duty cycle α 3H =1.

[0114] Finally, we will consider a third case (called the lowest voltage case) where the voltage on phase b associated with the faulty switching arm 2 is less than the voltages of the functional arms 1 and 3, and consider two sub-cases by using similar arguments as for the case called the highest voltage case:

[0115] - In range C1, the phase voltage V of the first active arm 1 a Greater than the phase voltage V of the second active arm 3 c , and therefore the first phase voltage value V a and the second phase voltage value V c The voltage difference between V a -V c With control voltage value V 13 the same symbol; and

[0116] - In range C6, the phase voltage V of the first active arm 1 a is less than the phase voltage V of the second active arm 3 c , and therefore the first phase voltage value V a and the second phase voltage value V c The voltage difference between V a -V c With control voltage value V 13 Opposite signs.

[0117] In this example of embodiment, in the sub-case of range C1 , the voltage of the faulty arm 2 is the lowest and the switch M3L cannot be opened as this would risk creating a more favorable path through the faulty arm 2 .

[0118] Therefore, switch M3L remains closed.

[0119] When switch M3L is closed, the return path through the second active arm 3 remains favorable, experiencing the same V as before. DC voltage condition. Therefore, within this range, V DC It must also be set to greater than 487V.

[0120] Therefore, in the sub-case of range C1, the duty cycle α is controlled according to the following equation 1H The high switch M applied to the first active arm 1 1H :

[0121] α 1H =1-V 13 / (V DC ),

[0122] The low switch M3L of the second active arm 3 remains closed in the entire range C1, so that the duty cycle α 3L =1.

[0123] As in the sub-case of range C6, the duty cycle α is controlled according to the following equation 3H The high switch M applied to the second active arm 3 3H :

[0124] α 3H =1-V 31 / (V DC ),

[0125] It can also be written as:

[0126] α 3H =1+V 13 / (V DC ),

[0127] And the low switch M of the first active arm 1 1L C6 remains closed throughout the range, so that the duty cycle α 1L =1.

[0128] Thus, the availability of the battery charger of the motor vehicle can be increased without adding any auxiliary components, so that the motor vehicle can be recharged from the three-phase network even in the event of a partial failure of the three-phase Vienna rectifier.

Claims

1. A method for controlling a three-phase Vienna rectifier (20) comprising three switching arms (1, 2, 3), each switching arm being associated with an electrical phase (a, b, c), each switching arm (1, 2, 3) comprising a high-power controlled switch (M 1H , M 2H , M 3H ), the high controlled power switch and the low controlled power switch (M 1L , M 2L , M 3L ) are arranged in series and oppositely; wherein the high controlled power switch (M 1H , M 2H , M 3H ) is a first corresponding switch that operates when the corresponding input current is positive, and the low controlled power switch (M 1L , M 2L , M 3L ) is a second corresponding switch that operates when the corresponding input current is negative, when the switch arm includes a fault switch (M) that is blocked in the off state 2H , M 2L ), the method comprises: - Identify the faulty switch (M 2H , M 2L ) of the faulty switch arm (2) and the other two functioning arms (1, 3); -Receive control voltage value V 13 The step of controlling the voltage value corresponds to the voltage value to be applied between the two active arms (1, 3); - Output DC voltage (V DC ) is maintained at a value greater than the voltage difference between the two electrical phases at the input terminal of the three-phase Vienna rectifier, wherein the output DC voltage is independently controlled by a DC-DC converter connected at the output terminal of the three-phase Vienna rectifier; - Receive the measured DC voltage value (V DC ) steps; - According to the control voltage value V received between the two active arms 13 And the measured DC voltage value (V DC ) to calculate the duty cycle of the high controlled power switch and the low controlled power switch to be applied to the two active arms; as well as - a control step, the control step comprising applying the calculated duty cycle to the three-phase Vienna rectifier (20), wherein when the electrical phase associated with the switching arm including the fault switch provides a path that facilitates current flow during a certain time interval, during this time interval, the conductive switch of the switching arm whose associated electrical phase has a voltage between the voltages of the remaining two electrical phases remains closed.

2. The method according to claim 1, characterized in that Also according to the voltage value (V b ) and the first phase voltage value (V a ) and the second phase voltage value (V c ) are compared to calculate the duty cycle to be applied to the high controlled power switch and the low controlled power switch, the first phase voltage value corresponding to the phase (a) associated with the first active arm (1), and the second phase voltage value corresponding to the phase (c) associated with the second active arm (3).

3. The method according to claim 2, characterized in that When the voltage value (V b ) at the first phase voltage value (V a ) and the second phase voltage value (V c ), these duty cycles are simultaneously applied to the high-controlled power switch (M) of the first active arm (1) 1H ) and the low controlled power switch (M) of the second active arm (3) 3L ), the duty cycle is at least equal to the received control voltage value V 13 and twice the measured DC voltage value (V DC ) such that: a 1H =a 3L =1-V 13 / (2*V DC ); Among them, α 1H and α 3L are respectively a high controlled power switch (M) to be applied to the first active arm (1) 1H ) and the low-power controlled switch (M) of the second active arm (3) 3L ) duty cycle, V 13 is the control voltage value, and V DC is the measured DC voltage value.

4. The method according to claim 2 or 3, characterized in that: When the voltage value (V b ) is greater than the first phase voltage value (V a ) and the second phase voltage value (V c ), and When the first phase voltage value (V a ) and the second phase voltage value (V c ) between the voltage difference (V a -V c ) has the same control voltage value as V 13 When the same symbol The duty cycle is then applied to the low controlled power switch (M 3L ), the duty cycle is calculated so that it is at least equal to the control voltage value V 13 The measured DC voltage value (V DC ) such that: α 3L =1-V 13 / V DC , The high-power controlled switch (M) of the first active arm (1) 1H ) remains closed; where α 3L is a low controlled power switch (M) to be applied to the second active arm (3) 3L ) duty cycle, V 13 is the control voltage value, and V DC is the measured DC voltage value.

5. The method according to claim 2 or 3, characterized in that: When the voltage value (V b ) is greater than the first phase voltage value (V a ) and the second phase voltage value (V c ), and When the first phase voltage value (V a ) and the second phase voltage value (V c ) between the voltage difference (V a -V c ) has the same control voltage value as V 13 When the signs are opposite, The duty cycle is then applied to the low controlled power switch (M 1L ), this duty cycle is calculated so that it is equal to not more than the control voltage value V 13 The measured DC voltage value (V DC ) such that: α 1L =1+V 13 / V DC ; The high-power switch (M) of the second active arm (3) 3H ) remains closed; where α 1L is a low controlled power switch (M) to be applied to the first active arm (1) 1L ) duty cycle, V 13 is the control voltage value, and V DC is the measured DC voltage value.

6. The method according to claim 2 or 3, characterized in that: When the voltage value (V b ) is less than the first phase voltage value (V a ) and the second phase voltage value (V c ), and When the first phase voltage value (V a ) and the second phase voltage value (V c ) between the voltage difference (V a -V c ) has the same control voltage value as V 13 When the same symbol The duty cycle is then applied to the high controlled power switch (M 1H ), this duty cycle is calculated so that it is at least equal to the received control voltage value V 13 The measured DC voltage value (V DC ) such that: α 1H =1-V 13 / V DC ; The low-power controlled switch (M) of the second active arm (3) 3L ) remains closed; where α 1H is a high controlled power switch (M) to be applied to the first active arm (1) 1H ) duty cycle, V 13 is the control voltage value, and V DC is the measured DC voltage value.

7. The method according to claim 2 or 3, characterized in that: When the voltage value (V b ) is less than the first phase voltage value (V a ) and the second phase voltage value (V c ), and When the first phase voltage value (V a ) and the second phase voltage value (V c ) between the voltage difference (V a -V c ) has the same control voltage value as V 13 When the signs are opposite, The duty cycle is then applied to the high controlled power switch (M 3H ), this duty cycle is calculated so that it is equal to not more than the received control voltage value V 13 The measured DC voltage value (V DC ) such that: α 3H =1+V 13 / V DC ; Among them, α 3H is a high controlled power switch (M) to be applied to the second active arm (3) 3H ) duty cycle, V 13 is the control voltage value, and V DC is the measured DC voltage value; The low controlled power switch (M1L) of the first active arm (1) remains closed.

8. A device for controlling a three-phase Vienna rectifier (20) comprising three switching arms (1, 2, 3), each switching arm being associated with an electrical phase (a, b, c), each switching arm (1, 2, 3) comprising a high-power controlled switch (M 1H , M 2H , M 3H ), the high controlled power switch and the low controlled power switch (M 1L , M 2L , M 3L ) are arranged in series and oppositely, wherein the high controlled power switch (M 1H , M 2H , M 3H ) is a first corresponding switch that operates when the corresponding input current is positive, and the low controlled power switch (M 1L , M 2L , M 3L ) is a second corresponding switch that operates when the corresponding input current is negative, the device comprising: - For identification of faulty switches (M 2H , M 2L ) of the faulty switching arm (2) and the other two functioning arms (1, 3); - Used to receive the control voltage value V 13 Devices; - Used to receive the measured DC voltage value (V DC ) device, wherein the DC voltage value (V DC ) is independently controlled by a DC-DC converter connected at the output of a three-phase Vienna rectifier; - for receiving said control voltage value V according to the two active arms 13 and the measured DC voltage value (V DC ) to calculate the duty cycle of the high controlled power switch and the low controlled power switch to be applied to the two functional arms, and the calculation is made in such a way that no current flows through the faulty switch arm (2); - means for controlling the application of the calculated duty cycle to the three-phase Vienna rectifier (20); as well as A device for keeping closed the conductive switch of the switching arm having a voltage between the voltages of the other two electrical phases during a certain time interval when the electrical phase associated with the switching arm including the fault switch provides a path conducive to current flow during this time interval.

9. A battery charger designed to be connected to a three-phase power grid, the battery charger comprising: Designed to be connected to the line impedance of the three-phase grid, a first AC-DC converter comprising a three-phase Vienna rectifier, a second DC-DC converter connected to a battery pack, and a device for controlling the three-phase Vienna rectifier as claimed in claim 8.

10. A vehicle comprising the battery charger according to claim 9.

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