EP3513473A1

EP3513473A1 - System for transferring electrical power

Info

Publication number: EP3513473A1
Application number: EP17780802.9A
Authority: EP
Inventors: Philippe Masson; Yejin JIN; Christophe Louise; Luc Kobylanski
Original assignee: Valeo Equipements Electriques Moteur SAS
Current assignee: Valeo Electrification
Priority date: 2016-09-14
Filing date: 2017-09-13
Publication date: 2019-07-24
Also published as: FR3056037B1; FR3056037A1; WO2018051013A1

Abstract

System (1) for transferring electrical power comprising: - a rotary electric machine (20) comprising a stator, said stator comprising a winding (30) that is capable of being electrically linked to a first and a second electrical network (27, 28); - an inverter (21) that is positioned between the first electrical network and the winding (30); - a first connection terminal (S) for linking the inverter (21) to said first electrical network (28); - a winding terminal (104) for linking the winding (30) to said second electrical network (27). Provision is made for the system to comprise a selection switch (101) that is positioned between the second electrical network (27) and the first (S) and second network terminals (104) for the purpose of selectively connecting the second electrical network (27) to the first connection terminal (S) or to the winding terminal (104).

Description

ELECTRIC POWER TRANSFER SYSTEM

TECHNICAL FIELD OF THE INVENTION

The present invention relates to a system for transferring electrical power between two electrical networks by using part of the components of a rotating electrical machine, this transfer system being found in a motor vehicle.

BACKGROUND TECHNOLOGY

Motor vehicles equipped with a heat engine also include an electric machine capable of operating in an alternator mode or a motor mode. During the engine mode, the electric machine exerts a motor torque on a crankshaft of the motor vehicle while in the alternator mode the electric machine exerts a resistance torque on the crankshaft of the motor vehicle.

It is known from patent application FR2803447A1 a power generation system, for a two-voltage electrical network comprising a first electrical network 28 and a second electrical network 27, comprising a three-phase alternator type electrical machine whose stator phases are rectified. to generate the desired power on the first electrical network 28 operating at a first voltage value Us, and whose stator is wound in a star so as to have a neutral point N to which the second electrical network 27 operating at a second value of Ub voltage lower than the first, the system further comprises electronic control means 22 and voltage regulation Us and Ub of the two electrical networks. A block diagram incorporating the principle of the patent application FR2803447A1 is reproduced in FIG. FIG. 1 illustrates a power generation system 1 for a two-voltage electrical network which comprises a three-phase electrical machine 20 of the alternator type, which can be synchronous with a wound rotor or with magnets, or else with a coiled and magnet winding. The stator phases are rectified to generate the power desired on the first electrical network 28 operating at a first voltage value Us.

It can also be an asynchronous alternator. It is star-wound to the stator so as to have a neutral point N to which is connected the second electrical network 27 operating at a second voltage value Ub lower than the first voltage value Us.

To rectify the current of the stator phases of the alternator, these three phases are connected to a three-phase inverter 21, which delivers a voltage Us, equal to 42 volts in the particular case of a current motor vehicle, and which consists of six switches H1 to H3 and L1 to L3. They are arranged in three arms of two switches each, mounted in series and in the same direction, one Li "low-side" between the mass and one of the phases and the other Hi "high-side" between the phase and the upper voltage Us. These switches are transistors of MOSFET or IGBT or bipolar or other type, associated or not with a reverse diode.

They are controlled by electronic control and regulation means 22 which receive instructions for regulating the voltages Us and Ub of the two electrical networks, coming from a computer 99 establishing electronic strategies for managing the electrical energy of the network. These control means 22 can also receive information on the position of the rotor relative to the stator on the part of a position sensor 32.

Two filtering means 23 and 24 may be respectively arranged at the entrance of each of the two electrical networks, or at the neutral point N, to the second network 27 at 14 volts and at the output S of the control circuit, to the first network 28 to 42 volts.

These means consist for example of capacities associated with inductances sized to deliver filtered continuous voltages remaining within the tolerances allowed for the application, in terms of emission and electromagnetic susceptibility. These two electrical networks can each be connected to a battery, referenced respectively 25 and 26, and supply the electrical networks 27 and 28 operating respectively at 14 volts and 42 volts.

When the electric machine 20 is in motion, alternator mode driven by the vehicle engine or starter mode to drive instead the engine, the connection of its neutral point N to the second electrical network 27 to 14 volts imposes the average polarization of the three phases of the stator at the same potential Ub of 14 volts, whose impedances in continuous mode are equivalent to the resistances of the windings. The voltage regulation on the second electrical network 27 of 14 volts is obtained by adjusting the average value of the three phase voltages, that is to say by adjusting the three control signals of the machine. three-phase electric delivered by the electronic control and regulation of the voltages Us and Ub of the dual-voltage network. There are two conventional methods of controlling this alternator, or alternator-starter.

According to a first variant embodiment, the regulation of these two voltages is carried out according to a method of pulse width modulation of the control signals of the transistors constituting the arms of the inverter, in order to generate three periodic waves on the three phases. of sinusoidal shape, trapezoidal, triangular for example, shifted by 120 ° from each other. This method is applicable to electrical machines of the wound rotor type or of the permanent magnet type.

According to a second variant embodiment, the regulation is carried out according to a "full wave" control method of the synchronous rectification type, applicable only to synchronous electric machines with wound rotor.

In the case of both methods, the average voltage Umoy of the three stator voltages must be enslaved at the three output points P1, P2 and P3 of the phases at a necessary setpoint voltage for the regulation of the second network 27 at 14 volts. In the case of the first embodiment using a pulse width modulation method, the regulation of the upper voltage Us, equal to 42 volts in particular, is achieved by two parameters: the adjustment of the amplitude of the phase instructions and adjusting either the excitation of the rotor in the case of a wound rotor synchronous alternator, or the speed slip existing between the speed of the stator rotating field and the mechanical rotational speed of the rotor in the case of an alternator asynchronous, or the phase shift between the stator magnetic field and the rotor flux in the case of a permanent magnet synchronous alternator. When the electric machine is stopped, that is to say when the rotor does not rotate, in voltage converter mode, a suitable control of the three arms of the inverter, by the control circuit 22, makes it possible to perform a energy transfer from one of the two networks, 14 or 42 volts, to the other. The structure of the static converter thus obtained is of the voltage booster type or voltage buckener also called Buck according to an Anglo-Saxon term well known to those skilled in the art.

The principle and the realization of the control of this system when the machine is at a standstill, that is to say when the rotor does not rotate or in motion, that is to say when the rotor turns, is described in the patent application FR2803447A1 which the skilled person can refer for more details.

This system is satisfactory, however, it may be desirable to further improve it.

This type of system has the defect that it does not allow to inject a lot of power to the second grid 27 at least with a reasonable cost and good performance. Indeed, for an increase in the current of a certain value at the neutral point, it is necessary to provide an increase of a level equal to this value on each of the three phases. It is therefore necessary to provide a dimensioning of the inverter so that it can support three times the current increase value. This requires the use of an inverter of another dimensioning whose price will increase significantly. On the other hand, always supporting three Once the current increase value, the joules losses will increase significantly so that the yield will decrease.

Thus, with this system, and especially when the power to be transferred is important, the gain of one gram of carbon dioxide per kilometer will represent a significant cost.

OBJECT OF THE INVENTION

The object of the invention is to respond to this desire while at the same time remedying at least one of these aforementioned drawbacks.

According to the invention there is provided an electric power transfer system comprising:

a rotating electrical machine comprising a rotor and a stator, said stator comprising a winding which is provided with at least three phase windings and which is able to be electrically connected on the one hand to a first electrical network having a high voltage and on the other hand to a second electrical network having a low voltage;

a first connection terminal adapted to be connected to the first electrical network;

a second connection terminal adapted to be connected to the second electrical network;

an inverter arranged between the first connection terminal and the winding, the inverter comprising for each of the phase windings at least one switch that can assume a blocked or on state;

a winding terminal connected directly to the stator winding;

a switch control module configured to be able to control the state of the switches of the inverter so that the potential of the winding terminal is of the order of low voltage;

According to one general characteristic, the transfer system comprises a selection switch arranged between firstly the second connection terminal and secondly the first connection terminal and the winding terminal for selectively connecting the second connection terminal to the second terminal. first connection terminal or the winding terminal for transferring electrical power to the second network from the first connection terminal or the winding terminal.

In other words, the first connection terminal is adapted to connect the inverter to said first electrical network while the winding terminal is adapted to connect the winding to said second electrical network.

For example, it can be provided that the second connection terminal is connected directly to the second power grid.

Using the power transfer from the electrical machine to the second network when the electric machine operates in low voltage mode, the transferable power is increased without additional cost and with satisfactory performance. Indeed, with a power to be transferred more important one can keep the same inverter and the losses by Joule effect increase only moderately.

In addition, while retaining the possibility of transferring the power from a winding terminal to the second network, one can firstly use the energy stored in a battery connected to the first network if necessary. On the other hand, we can continue the use of the rotating electrical machine in connection with the first network while allowing a supply of the second network and if necessary a low voltage battery connected to the second network.

Thus, it is possible to substantially increase the number of grams of carbon dioxide saved per kilometer with a cost related to the amount of grams of carbon dioxide saved low. On the other hand, the efficiency is greatly improved with respect to a power transfer only from the winding terminal.

To control the potential of the winding terminal, the state of the switches of the inverter can be controlled so that a continuous value is added to the potential of each of the three output points P1, P2 and P3 of the phase windings. It is also possible when the rotor of the electrical machine does not turn to provide that the control module is configured to control the state of the switches of the inverter so that the Winding windings form a storage element of a Buck type converter.

To control the potential of the first connection terminal, it is possible when the electric machine operates in low voltage mode, to lower the output voltage of the rotating electrical machine so that it reaches for example 12 volts.

For this, it is possible, with respect to an operation of the electric machine during which it operates in high voltage mode with the first power grid, to lower the current that enters the rotor winding if necessary. It is also possible to do defluxing according to an electric machine control principle known to those skilled in the art and explained below.

According to other characteristics taken separately or in combination:

the phase windings are star-coupled so that the winding comprises a neutral point, said winding terminal being connected directly to the neutral point.

In the case of a three-phase dual winding comprising one or more neutral points, it is possible to choose to use only one neutral point to be connected to the winding terminal. The use of the neutral point allows a simple control of the potential of the winding terminal.

each phase winding comprising a phase output point, said winding terminal is connected directly to one of the phase output points.

Particularly in the case where the windings are coupled in a triangle and in the absence of a neutral point, then the winding terminal can be connected to one of the phase windings.

the electric power transfer system is configured to operate with first and second electrical networks having a ratio between low voltage and high voltage of between 35% and 65%. It is thus possible to operate the electric machine with a good efficiency on the one hand and by limiting the losses on the other hand. Indeed, in order to operate the electric machine with good performance, it ensures a maximum excursion of the potential amplitude of each of the phase output points. For this, it is necessary that their ripple is centered on half of the high voltage of the first network and we then obtain that the potential of the neutral takes substantially the value of half of the high voltage.

By choosing a low voltage which is also of the order of half of the high voltage limit, when the excursion of the amplitude of the potential of each of the phase output points is maximum, the potential difference between the low voltage and the potential of the winding terminal which makes it possible to limit the losses iron during the transfer of power.

the electric power transfer system is configured to operate with first and second electrical networks having a high voltage of between 20 and 30 volts and a low voltage of between 11 and 15 volts.

This is an embodiment in which the transfer system can operate in particular with a first network having a high voltage of 24 volts and a second network having a low voltage of 12 volts. These two values are widely used in the automotive field and therefore allow the system according to this configuration to be easily integrated into a vehicle.

the electric power transfer system comprises a safety switch which can take on or off status and is arranged between the first connection terminal and the first electrical network.

The safety switch can assume a blocked state in order to avoid a short circuit between the first connection terminal and the high voltage battery when the potential of the first connection terminal is different from the high voltage, especially when the electrical machine is operating in the operating mode. low tension.

the control module is configured to control the state of the security switch and the selection switch so that the security switch takes the off state when the first connection terminal is connected to the second connection terminal. It is thus possible to disconnect the high voltage battery when the first connection terminal is connected to the second electrical network. Indeed, without this disconnection there would be a risk of short circuit because of the electrical connection of the second electrical network having a low voltage to the high voltage battery.

the first connection terminal is connected directly to the first electrical network.

In the case of a first power grid connected to an ultra capacity, the voltage at its terminals being adjustable, there is no risk of short circuit. the rotor comprises a winding for generating a magnetic field, the winding of the rotor being electrically connected to the first connection terminal.

For example, to electrically connect the rotor winding to the first connection terminal, a collector and brushes are used.

the winding of the rotor is connected to the first connection terminal via a regulator and the control module is configured to act on the regulator to lower the current in the rotor winding so that the potential of the first connection terminal is of the order of low voltage.

Thus, in low voltage mode of the electrical machine, it is possible to reduce the potential of the first connection terminal to approach the low voltage and thus to allow power transfer from the first connection terminal to the second electrical network.

the winding of the rotor is electrically connected to the winding terminal by means of a passing diode for the positive current flowing from the winding terminal to the rotor winding.

Thus, it is possible to provide a supply of the rotor winding via the first connection terminal or the winding terminal.

the system comprises a first filtering capacitor connected in parallel with the first connection terminal and a second filtering capacitor connected in parallel with the second connection terminal. One of these filtering capabilities can be used for the transfer system to function as a buck converter.

the switches of the inverter each comprise a switch and a diode, these two elements being connected in parallel.

The diodes and switches can also be used for the transfer system to function as a buck converter.

the switches of the inverter comprise MOSFET transistors.

MOSFET transistors can participate in the role of a Buck converter and also allow sophisticated control, which is useful for example for the purpose of defluxing.

the control module is configured to control the state of the switches of the inverter so that the potential of the first connection terminal is of the order of the low voltage of the second network.

It is then a command to operate the electric machine in low voltage mode. For example, it is a defluxing control that lowers the total flux of the stator winding by adding, with the help of the switches of the inverter, a voltage out of phase with the electromotive force of the stator winding. The defluxing control can be used in particular when the rotor has no winding but permanent magnets.

BRIEF DESCRIPTION OF THE FIGURES

Other features and advantages of the invention will become apparent on examining the detailed description of embodiments and embodiments, in no way limiting, and the accompanying drawings in which: FIG. 1, already described, represents a diagram functional of a power transfer system according to the state of the art;

FIGS. 2 and 3 show a block diagram of a power transfer system according to a first embodiment of the invention;

FIG. 4 represents a block diagram of a power transfer system according to a second embodiment of the invention; FIG. 5 represents a block diagram of a portion of a power transfer system according to a third embodiment of the invention; and

FIG. 6 represents a block diagram of a portion of a power transfer system according to a fourth embodiment of the invention.

Identical, similar or similar elements retain the same reference from one figure to another.

DESCRIPTION OF EXAMPLES OF EMBODIMENT OF THE INVENTION

In the remainder of the description, modes of operation of the transfer system 1 as well as modes of operation of the electric machine are defined. For a mode of operation of the transfer system several modes of operation of the electric machine are possible.

By direct connection to a component, it is meant to be connected to this component directly without any other electrical component other than a wire or a connecting means. By component electrically connected to another component is meant the fact that electrical contact is possible between the two components directly or through other electrical components. The term "component capable of being connected to another component" means that electrical contact is possible between the two components, in particular intermittently.

FIG. 2 represents a block diagram of a power transfer system according to a first embodiment of the invention. Figure 3 also shows a more detailed block diagram of this first embodiment of the invention.

The power transfer system 1 according to the first embodiment differs from that of the state of the art illustrated in FIG. 1 notably in that it provides a selection switch 101.

Thus, the power transfer system 1 according to the first embodiment comprises: a rotary electrical machine comprising a rotor 29 and a stator, said stator comprising a winding 30 which is provided with at least three phase windings 31, 35, 33 and which is able to be electrically connected on the one hand to a first electrical network 28 having a high voltage Us for example continuous and secondly to a second electrical network 27 having a low voltage Ub for example continuous;

a first connection terminal S adapted to be connected to the first electrical network 28;

a second connection terminal 105 adapted to be connected to the second electrical network 27;

an inverter 21 arranged between the first connection terminal S and the winding 30, the inverter comprising for each of the phase windings at least one switch H1, L1, H2, L2, H3, L3 that can assume a blocked or on state;

a winding terminal 104 connected directly to the winding 30 of the stator; and

a control module 22 of the switches configured to be able to control the state of the switches of the inverter 21 so that the potential of the winding terminal 104 is of the order of the low voltage Ub. The selection switch 101 is disposed between firstly the second connection terminal 105 and secondly the first connection terminal S and the winding terminal 104 for selectively connecting the second connection terminal 105 to the first connection terminal S or the terminal of winding 104 to transfer electrical power to the second network 27 from the first connection terminal S or the winding terminal 104.

Thus, the selection switch 101 allows the power transfer system 1 to operate in two modes of operation. More specifically, when the selection switch 101 connects the second connection terminal 105 to the first connection terminal S, then the transfer system 1 operates in a first mode of operation called mode A allowing a transfer of electrical power to the second network. from the first connection terminal S. And, when the selection switch 101 connects the second connection terminal 105 to the winding terminal 104, then the transfer system 1 operates according to a second mode of operation called mode B allowing a transfer of electrical power to the second network from the terminal winding 104.

For example, as illustrated in FIGS. 2 and 3, the first network 28 is connected to a high voltage battery 26 having the high voltage Us as the continuous voltage while the second network 27 is connected to a low voltage battery 25 having as its nominal voltage continue the low voltage Ub. It can be expected that the ratio between the low voltage Ub of the second network 27 and the high voltage Us of the first network 28 is between 35% and 65%. For example, the high voltage Us of the first network 28 is between 20 and 30 volts and the low voltage Ub of the second network 27 is between 11 and 15 volts.

In addition, as illustrated in FIG. 3, the rotor 29 may comprise a coil 34 for generating a magnetic field, said rotor winding 34 being electrically connected to the first connection terminal S. For example, it is possible for the rotor winding to be provided. 34 is electrically connected to the winding terminal 104 by means of a pass diode 103 for the positive current flowing from the winding terminal 104 to the winding of the rotor 34. The rotor 29 is thus powered on the one hand by the first connection terminal S but also through the winding terminal 104. This supply by the winding terminal 104 occurs because of the diode 103, in the case where the potential of the winding terminal 104 is greater than that of the first terminal connection S.

As illustrated in FIG. 3, for the winding 30, each phase winding 31, 35, 33 comprises a phase output point P1, P2, P3. According to the first embodiment of the invention, the phase windings 31, 35, 33 are star-coupled so that the winding comprises a neutral point N, said winding terminal 104 being connected directly to the neutral point N. Moreover, , the control module is advantageously connected to a position sensor 32 to provide information on the position of the rotor 29 relative to the stator. According to the mode A of the transfer system 1, the electrical machine 20 operates in low voltage mode Ub with the second electrical network 27 and when it is used as an alternator delivers a DC voltage of the order of the low voltage Ub, for example 12 volts. Low-voltage mode of the electrical machine 20 means an operating mode in which the electrical machine 20 operates with the second electrical network. It can then operate according to modes of operation such as Alternator, but also "Regen" and "Boost", according to Anglo-Saxon terms well known to those skilled in the art and defined below. In mode A of the transfer system 1, for the electrical machine 20 to operate with the second electrical network, the control module 22 controls the state of the switches H1, H2, H3, L1, L2, L3 of the inverter 21 of so that the potential of the first connection terminal S is of the order of the low voltage Ub of the second network 27. For this, it is possible according to a first example to reduce the flux of the stator winding by defluxing caused by the addition to the using the inverter switches H1, H2, H3, L1, L2, L3, a voltage out of phase with the electromotive force of the winding 30 of the stator. Defluxing is applicable even when the rotor has no winding and is equipped with a permanent magnet. For this, one can according to a second example when the rotor is provided with a coil 34 adjust the current in the rotor winding 34 so that the potential of the first connection terminal S is of the order of low voltage Ub.

In the case where the first network 28 is connected to a high voltage battery 26, the system can then then comprise a safety switch 102 which can assume an on or off state arranged between the first connection terminal S and the high voltage battery 26.

The use of this safety switch 102 is advantageous according to the mode A. Indeed, when the first connection terminal S is connected to the second electrical network 27, then the electrical machine 20 operates in low voltage mode Ub so that the connection between the first connection terminal S and the first network would cause a short circuit. The control module 22 is then configured to control the state of the security switch 102 and the selection switch 101 so that the security switch 102 takes the off state when the first connection terminal S is connected to the second power grid. 27. According to the mode B of the transfer system 1, the electrical machine 20 operates in high voltage mode Us with the first power grid 28 and when it is used as an alternator it delivers a DC voltage of the order of the high voltage Us However, according to the mode B of the transfer system 1, the winding terminal 104 is connected to the second connection terminal 105 to supply a low voltage voltage Ub to the second power grid. High voltage mode of the electrical machine 20 means an operating mode in which the electrical machine 20 operates with the first electrical network. It can then operate according to modes of operation such as Alternator, but also "Recrank", "Regen" and "Boost", according to Anglo-Saxon terms well known to those skilled in the art and defined below.

For the winding terminal 104 to reach the low voltage Ub, reference can be made to the patent FR2803447 which details the control of the control module 22 on the state of the switches H1, L1, H2, L2, H3, L3 of the inverter 21 so that the potential of the winding terminal 104 is of the order of the low voltage Ub depending on whether the rotor 29 of the electric machine is rotated or is stopped.

On the other hand, according to the mode B, while the winding terminal 104 supplies a voltage to the second electric network 27, the electric machine 20 can continue to be used to function as an alternator, but also to make "Regen", " Boost "," Recrank "according to Anglo-Saxon terms well known to those skilled in the art and defined below. This is possible in particular by controlling the rotor and stator currents via the switches of the inverter 21 in the case where these switches comprise MOSFET transistors.

The operating mode of the electric machine "Regen" consists, for example, in operating the electric machine in a pulse mode, each pulse lasting 5-30 seconds. During each pulse, the electric machine is then used in alternator mode with a strong current rotor and stator which generates a strong resistance torque on the crankshaft which allows to brake the motor vehicle. Thus, the electrical power delivered to the first power grid is of the order of 10 kW.

The operating mode of the electric machine "Boost" also called "Torque Assist" according to another Anglo-Saxon term well known to those skilled in the art consists, for example, in operating the electric machine in a pulse mode, each pulse lasting from 5-30 seconds. During each pulse, the electric machine is then used in motor mode with high rotor and stator currents that generate a high engine torque on the crankshaft which makes it possible to accelerate the motor vehicle. For example, the electrical power consumed by the rotating electrical machine is then of the order of 10 kW. For this, the electrical machine is powered for example by the second power grid or the first power grid.

The operating mode of the electric alternator machine consists for example in operating the electric machine in a continuous mode. The electric machine is used in alternator mode with rotor and stator currents that generate a resistance torque on the crankshaft which allows a generation of electrical power stored in the high voltage battery 26. For example, the electrical power is then the order of 3 kW.

The operating mode of the electrical machine "Recrank" consists for example in operating the electric machine in a pulse mode, each pulse lasting less than one second. During each pulse, the electric machine is then used in engine mode and generates a motor torque on the crankshaft which makes it possible to start the engine of the motor vehicle. For this, the electric machine is powered for example by the first power grid.

For example, a first filtering capacitor 24 is connected in parallel with the first connection terminal S and a second filtering capacitor 23 is connected in parallel with the second connection terminal 105 on the other hand.

In other words, the first filtering capacitor 24 is connected to the first connection terminal S on the one hand and to a mass of the power transfer system. Similarly, the second filtering capacitor 23 is connected to the second connection terminal 105 on the one hand and to a mass of the power transfer system on the other hand.

In addition, the switches H1, H2, H3, L1, L2, L3 of the inverter 21 may each comprise a switch and a diode, these two elements being connected in parallel.

In mode B of the transfer system 1, these diodes and these filtering capabilities can participate in the role of a Buck converter from the first network to the second network especially when the rotor 29 is not driven. Indeed, to achieve this type of converter, it is necessary the following three elements: a cutting element, it is the switches switches H1, H2, H3, L1, L2, L3;

a storage element is the windings 31, 33, 35; and

a rectifying element, it concerns the filtering capacitance 23 or 24 and the diodes. Of course, in the case where the switches comprise MOSFET transistors, operation in Buck converter mode is also possible, the cutting being performed using MOSFET transistors.

Furthermore, with the aid of the control module 22, it is possible to trigger the operation according to the mode A or the mode B according to two main criteria, namely the state of charge of the high voltage battery 26 hereinafter referred to as SOCHT and the electrical load of consumers such as air conditioning, the seat heating function on the second electrical network 27 hereinafter called LOADBT. More precisely, two high and low levels are defined for the two criteria SOCHT and LOADBT and we obtain triggers of the operation according to the mode A and the mode B as hereinafter:

- LOADBT = up and SOCHT = up: mode B of the transfer system with a control of the electric machine according to which only the mode

Recrank is enabled and other operating modes of the electrical machine such as Alternator, Regen, Boost are not enabled. For example, in the case where the rotor does not rotate one can simply control the switches H1, H2, H3, L1, L2, L3 so that we have an operation of the power transfer system 1 as a Buck converter.

- LOADBT = high and SOCHT = low: the transfer system must switch to A mode operation, and the electrical machine to low voltage mode. During the transition from mode B to mode A, it is possible to prevent a transient voltage drop of the second network 27 from not immediately activating a consumer of the vehicle connected to the second network requiring a lot of power during a transition period, for example 500 ms. . Then, when the electric machine operates in low-voltage mode in continuous mode, the consumer is activated, then a time shedding has been carried out.

- LOADBT = low and SOCHT = high: mode B of the transfer system with a control of the electric machine according to which other modes of operation such as Alternator, Regen, Boost or Recrank can be activated. In addition, in the case where the rotor does not rotate, one can simply control the switches H1, H2, H3, L1, L2, L3 so that one operation of the power transfer system 1 as a Buck converter.

- LOADBT = low and SOCHT = low: mode A of the transfer system, the electric machine then operates in low voltage mode. In this case, it is possible in addition to the mode A to provide for operation of the Regen, Recrank or Boost modes by intermittently activating the B mode.

These triggers are advantageous, since when the SOCHT is high, it is interesting to operate the electrical machine 20 with the first one. network and use the charge of the high voltage battery 26 to discharge it to the low voltage battery 25.

FIG. 4 represents a block diagram of a power transfer system according to a second embodiment of the invention.

The second embodiment differs from the first embodiment in that the phase windings 31, 33, 35 are coupled in a triangle and in this case the winding terminal 104 is connected directly to one of the phase output points P1, P2, P3.

It is indeed possible, in a manner similar to the voltage regulation of a neutral point, to regulate the potential of one of the phase output points, here P1 so that it is of the order of the voltage Ub.

FIG. 5 is a block diagram of part of a power transfer system 1 according to a third embodiment of the invention.

This figure illustrates the filtering capacitor 24 and the first connection terminal S connected to the first electrical network 28, the first electrical network being connected to a high-voltage capacitance capacitor 37 instead of the high-voltage battery 26.

This third embodiment differs from the first and second embodiments in that the first connection terminal S is connected directly to the first electrical network 28.

Indeed, in the case of an ultra capacitance 37, the voltage at its terminals being adjustable, there is no risk of short circuit when the electrical machine 20 operates in low voltage mode while the power transfer system 1 is in the operating mode A. It is therefore not necessary to have between the connection terminal S and the first electrical network 28, the security switch 102.

Figure 6 shows a block diagram of a portion of a power transfer system according to a fourth embodiment of the invention. This figure illustrates:

the first connection terminal S; the filtering capacity 24;

the winding terminal 104;

the diode 103;

the electric machine 20 comprising the stator comprising the winding 30 having a neutral point N and the rotor 29 provided with a coil 34; and

a regulator 36 disposed between the diode 103 and the first connection terminal S on the one hand and the winding of the rotor 34 on the other hand.

The fourth embodiment of the invention differs from the first, second and third embodiments due to the presence of this regulator 36.

Thus, in the case where the rotor 29 comprises a coil 34 for generating a magnetic field, this winding of the rotor 34 can, according to the fourth embodiment, be connected to the first connection terminal S via the regulator 36, the control module 22 being configured to act on the regulator 36.

It is thus possible in particular to lower the current in the rotor winding 34 so that the potential of the first connection terminal S is of the order of the low voltage Ub when the electric machine 20 is used in low voltage mode with the second network. when the transfer system is in mode A.

Claims

1. Electric power transfer system (1) comprising:

a rotary electric machine (20) comprising a rotor (29) and a stator, said stator comprising a winding (30) which is provided with at least three phase windings (31, 35, 33) and which is suitable for being electrically connected firstly to a first power grid (28) having a high voltage (Us) and secondly to a second power grid (27) having a low voltage (Ub);

a first connection terminal (S) adapted to be connected to the first electrical network (28);

a second connection terminal (105) adapted to be connected to the second electrical network (27);

an inverter (21) arranged between the first connection terminal (S) and the winding (30), the inverter comprising for each of the phase windings at least one switch (H1, L1, H2, L2, H3, L3) can take a blocked state or passing;

a winding terminal (104) connected directly to the winding (30) of the stator; and

a control module (22) for the switches configured to be able to control the state of the switches of the inverter (21) so that the potential of the winding terminal (104) is of the order of the low voltage (Ub) )

characterized in that the transfer system (1) comprises a selection switch (101) arranged between firstly the second connection terminal (105) and secondly the first connection terminal (S) and the terminal of coil (104) for selectively connecting the second connection terminal (105) to the first connection terminal (S) or the winding terminal (104) for transferring electrical power to the second network (27) from the first connection terminal (S) or the winding terminal (104).

Electric power transfer system (1) according to claim 1, characterized in that the phase windings (31, 35, 33) are coupled in a star so that the winding (30) comprises a neutral point (N), said winding terminal (104) being connected directly to the neutral point (N).

Electric power transfer system (1) according to claim 1 or 2, characterized in that each phase winding (31, 35, 33) comprising a phase exit point (P1, P2, P3), said terminal coil (104) is connected directly to one of the phase output points (P1, P2, P3).

4. System for transferring (1) electric power according to one of the preceding claims, characterized in that it is configured to operate with a first (28) and a second (27) electrical networks having a ratio between the low voltage (Ub) and the high voltage (Us) between 35% and 65%.

Electric power transfer system (1) according to one of the preceding claims, characterized in that it is configured to operate with a first (28) and a second (27) electrical network having a high voltage (Us). between 20 and 30 volts and a low voltage (Ub) between 1 1 and 15 volts.

6. System for transferring (1) electric power according to one of the preceding claims, characterized in that it comprises a safety switch (102) that can take an on state or blocked arranged between the first connection terminal (S) and the first power grid (28).

Electrical power transfer system (1) according to the preceding claim, characterized in that the control module (22) is configured to control the state of the safety switch (102) and the selector switch (101). so that the security switch (102) takes the off state when the first connection terminal (S) is connected to the second connection terminal (105).

Electric power transfer system (1) according to one of claims 1 to 5, characterized in that the first connection terminal

(S) is connected directly to the first power grid (28).

Electric power transfer system (1) according to one of the preceding claims, characterized in that the rotor (29) comprises a coil (34) for generating a magnetic field, the winding of the rotor (34) being electrically connected to the first connection terminal (S).

Electrical power transfer system (1) according to the preceding claim, characterized in that the winding of the rotor (34) is connected to the first connection terminal (S) via a regulator (36) and in that the control module (22) is configured to act on the regulator (36) to lower the current in the rotor winding (34) so that the potential of the first connection terminal (S) is equal to order of low voltage (Ub).

1 1. Electric power transfer system (1) according to claim 9 or 10, characterized in that the rotor winding (34) is electrically connected to the winding terminal (104) via a diode (103). for the positive current flowing from the winding terminal (104) to the rotor winding (34).

12. System for transferring (1) electric power according to one of the preceding claims, characterized in that it comprises a first filtering capacitor (24) connected in parallel with the first connection terminal (S) and a second capacitor filtering device (23) connected in parallel with the second connection terminal (105).

13. System for transferring (1) electric power according to one of the preceding claims, characterized in that the switches (H1, H2, H3, L1, L2, L3) of the inverter (21) each comprise a switch and a diode, these two elements being connected in parallel.

14. System for transferring (1) electric power according to one of claims 1 to 12, characterized in that the switches (H1, H2, H3,

L1, L2, L3) of the inverter (21) comprise MOSFET transistors.

Electric power transfer system (1) according to one of the preceding claims, characterized in that the control module (22) is configured to control the state of the switches (H1, H2, H3, L1, L2, L3) of the inverter (21) so that the potential of the first connection terminal (S) is of the order of the low voltage (Ub) of the second network (27).