Electrical installation with a DC voltage source supplying a battery-free electrical network

Abstract

The invention relates to an electrical installation (102) for a mobility vehicle (100), comprising: - a source (SC1) designed to supply a DC voltage (VB1) with respect to an electrical ground (GND2); - a battery-free network (LV1) connected to the electrical ground (GND2); and - a link (L1) connecting the DC voltage source (SC1) to the network (LV1), the electrical installation (102) further comprising: - at least one short-circuit switch (G3A, G3B; G4A, G4B) between the link (L1) and the electrical ground (GND2); and - a safety device (110) configured, in response to detecting a supply of electrical energy by the network (LV1) to the link (L1), to control the closing of each short-circuit switch (G3A, G3B; G4A, G4B) in order to discharge the energy supplied by the network (LV1) to the electrical ground (GND2).

Description

Description TITLE: ELECTRICAL INSTALLATION WITH A DC VOLTAGE SOURCE SUPPLYING A BATTERY-FREE ELECTRICAL NETWORK Technical field of the invention

[0001] The present invention relates to an electrical installation with a direct voltage source supplying an electrical network without a battery, a mobility device comprising such an electrical installation, and a method for evacuating energy returned by the electrical network, and a corresponding computer program.

[0002] A mobility device is, for example, a motorized land vehicle, a train, an aircraft, or a drone. A motorized land vehicle is, for example, a car, a motorcycle, a motorized bicycle, or a motorized wheelchair.

[0003] In the description and the claims that follow, an electrical voltage shall be qualified as high voltage when it is greater than 100V, preferably greater than 150V, and as low voltage when it is less than 100V. Technological background

[0004] We know from the state of the art an electrical installation for a mobility device, comprising: a source designed to provide a direct voltage with respect to an electrical ground; a network without a battery and connected to the electrical ground; and a link connecting the direct voltage source to the network.

[0005] However, it can happen that one of the network's devices feeds back electrical energy, that is, supplies electrical energy on the link connecting the source to the network. Such a feedback can occur when the device is subjected to an external load. For example, in the case of power steering, a sudden change of direction, such as one resulting from the wheels hitting an obstacle (curb, etc.), can cause such a feedback. It is then possible to control the source to absorb this electrical energy return. However, this is not always desirable or possible, for example, if the source is faulty. In this case, the electrical energy cannot be discharged through the link, so it accumulates in the network and causes a an increase in its voltage, possibly very significant. However, equipment, or even its safety mechanisms, can be damaged if the voltage becomes too high, which can endanger people.

[0006] It may therefore be desirable to plan an installation that makes it possible to overcome at least some of the aforementioned problems and constraints. Summary of the invention

[0007] An electrical installation is therefore proposed for a mobility device, comprising: a source designed to supply a direct voltage with respect to an electrical ground; a network without a battery and connected to the electrical ground; and a link connecting the direct voltage source to the network; characterized in that it further comprises: at least one short-circuit switch between the link and the electrical ground; and a safety device designed to, in response to the detection of an electrical energy supply from the network on the link, control the closing of each short-circuit switch to evacuate the energy supplied by the network to the electrical ground.

[0008] Thus, thanks to the invention, it is possible to redirect electrical energy towards the electrical mass.

[0009] The invention may further include one or more of the following optional features, in any technically feasible combination.

[0010] Optionally, the detection of the supply of electrical power by the network on the link includes the detection of an overvoltage of a network voltage and / or a reverse current leaving the network towards the source.

[0011] Optionally, the source is also an AC-DC converter having at least one switching arm between the link and the electrical ground, having two switches connected to each other at a midpoint, and the switching arm forms the short-circuit switch.

[0012] Optionally, the AC-DC converter also includes two switching arms, each forming a short-circuit switch.

[0013] Optionally, the safety device is also designed to control the closing of each short-circuit switch in response to the detection of a source failure, at the same time as the detection of the supply of electrical power by the network on the link.

[0014] Optionally, the safety device is also designed to, in response to detection that a voltage on the link is below a predefined threshold, deactivate the source.

[0015] A mobility device comprising an electrical installation according to the invention is also proposed.

[0016] Also proposed is a method for evacuating energy supplied by a network without a battery on a link connecting a DC voltage source to the network, the DC voltage source and the network being connected to an electrical ground, comprising: a detection of the supply of electrical energy by the network on the link; and in response, a command to close at least one short-circuit switch located between the link and the electrical ground, to evacuate the energy supplied by the network to the electrical ground.

[0017] Also proposed is a computer program downloadable from a communication network and / or recorded on a computer-readable medium, characterized in that it includes instructions for executing the steps of a process according to the invention, when said program is executed on a computer. Brief description of the figures

[0018] The invention will be better understood with the aid of the following description, given solely by way of example and made with reference to the accompanying drawings in which: Figure 1 is a highly simplified side view of a mobility device comprising an electrical installation according to the invention, Figure 2 is a simplified electrical circuit, illustrating in particular an electrical source of the electrical installation of Figure 1, comprising a battery and a DC-DC converter, Figure 3 is a block diagram of a method for controlling the DC-DC converter, and Figure 4 is a simplified electrical circuit of another example of an electrical installation according to the invention. Detailed description of the invention

[0019] With reference to Figure 1, a mobility device 100 in which the invention can be implemented will now be described. The mobility device 100 is, for example, a motor vehicle as illustrated.

[0020] The mobility device 100 includes an electrical installation 102 comprising a DC voltage source SC1, designed to provide a DC voltage VB1.

[0021] For example, the SC1 source includes a BAT1 battery designed to provide a DC voltage VBATI and a DC-DC1 voltage converter designed to convert the DC voltage VBATI into the DC voltage VB1. The DC voltage BAT1 is, for example, a high voltage, for example equal to 400V or 800V.

[0022] For example, the BAT1 battery comprises cells or accumulators in series. For example, the cells of the BAT1 battery are lithium-ion cells, or lithium-iron-phosphate cells (LFP cells), or lithium-nickel-manganese-cobalt cells (NMC cells).

[0023] The mobility device 100 may include an electric propulsion motor 106. In this case, the battery BAT1 is, for example, designed to electrically power the electric motor 106 from the VBATI voltage.

[0024] Furthermore, the electrical installation 102 also includes an LV1 network designed to be electrically powered by the direct current voltage VB1. For this purpose, the electrical installation 102 also includes an L1 connection between the source SC1 and the LV1 network, specifically so that the LV1 network receives the voltage VB1.

[0025] The LV1 network is battery-free, but includes Z1 equipment. When it is said that the LV1 network is battery-free, this means at a minimum that it lacks a battery designed to power the Z1 equipment and / or capable of storing a sufficient amount of electrical energy to deliver 1 kW for five seconds. Thus, the LV1 network may include electrical capacities which are therefore not batteries within the meaning of the present invention.

[0026] For example, the voltage VBATI is referenced with respect to a first electrical ground GND1, while the voltage VB1 is referenced with respect to a second electrical ground GND2, different from the first electrical ground GND1 (see figure 2).

[0027] The electrical installation 102 also includes a control device 108 for the DCDC1 converter. The control device 108 is thus designed to provide commands C1 to the DCDC1 converter.

[0028] During operation, the Z1 equipment in the LV1 network may occasionally feed back electrical energy. Since the LV1 network has no battery, this energy cannot be absorbed by the LV1 network and is therefore supplied via the L1 link. Under normal operation of the DCDC1 converter, this fed energy can be absorbed, for example, fed back to battery BAT1. However, if the DCDC1 converter fails and cannot transfer energy to battery BAT1, the VB1 voltage can increase significantly.

[0029] Thus, the electrical installation 102 also includes a safety device 110 designed to detect a supply of electrical energy by the LV1 network on the L1 link, and in response cause a short circuit between the L1 link and an electrical ground to evacuate the electrical energy supplied by the LV1 network to the electrical ground.

[0030] The control device 108 and / or the safety device 110 is, for example, a computer device, such as a computer or a set of computers, comprising a processing unit, such as a microprocessor, and a main memory designed to store instructions of a computer program so that the processing unit can execute them to carry out the steps that will be described later.

[0031] To detect the supply of electrical power from the LV1 network to the DCDC1 converter, the safety device 110 is designed, for example, to detect an overvoltage of the VB1 voltage used by the LV1 network. An overvoltage is detected, for example, when the voltage in question exceeds a predefined threshold. For this purpose, the electrical installation 102 includes, for example, a sensor CVBI voltage designed to measure VB1 voltage and transmit measurements to safety device 110.

[0032] Alternatively, or as a complement, the safety device 110 is, for example, designed to detect a reverse current 11, that is, a current flowing out of the LV1 network towards the SC1 source. For this purpose, the electrical installation 102 includes, for example, a current sensor CH designed to measure the reverse current 11 and transmit the measurements to the safety device 110.

[0033] The safety device 110 can be designed to automatically short-circuit the electrical power supply from the LV1 network to the SC1 source upon detection. Indeed, the detection of a high overvoltage and / or a high reverse current 11 may be sufficient to conclude that the SC1 source, and in particular the DCDC1 converter, is failing to absorb the returned electrical energy, and is therefore probably faulty.

[0034] Alternatively, the safety device 110 can be designed to trigger a short circuit only when it also detects a fault in the source SC1, and in particular in the DCDC1 converter. More specifically, to detect a fault in the DCDC1 converter, the safety device 110 is, for example, designed to detect a reset of the control device 108.

[0035] With reference to Figure 2, an example of the implementation of the DCDC1 converter will now be described.

[0036] The DCDC1 converter is, for example, a dual isolated bridge DC / DC converter, also known as a "Dual Active Bridge" converter. In this case, the DCDC1 converter includes, for example, a transformer T with a primary winding P and a secondary winding S. The DCDC1 converter also includes a first DC / AC conversion stage EC1 connected to the primary winding P of the transformer T, and a second AC / DC conversion stage EC2, mounted symmetrically with respect to the first conversion stage EC1 and connected to the secondary winding S of the transformer T.The DCDC1 converter also includes an output capacitor CS connected between the first output terminal S1 and the second electrical ground GND2 and an inductive circuit, here an inductance Ll, connected between the second conversion stage EC2 and the terminal of the output capacitor CS that is not connected to the second electrical ground GND2, i.e. to the terminal of the output capacitor CS connected to the first output terminal S1.

[0037] For example, the first conversion stage EC1 comprises an H-bridge with two switching arms B1, B2, each of the two switching arms B1, B2 having two switches G1A, G1B, G2A, G2B connected to each other at a midpoint. The first switching arm B1 has its midpoint connected to one end of the primary winding P of transformer T, while the second switching arm B2 has its midpoint connected to a second end, different from the first end, of the primary winding P of transformer T.

[0038] Similarly, for example, the second conversion stage EC2 comprises an H-bridge with two switching arms B3, B4, each of the two switching arms B3, B4 having two switches G3A, G3B, G4A, G4B connected to each other at a midpoint. The first switching arm B3 has its midpoint connected to one end of the secondary winding S of transformer T, while the second switching arm B4 has its midpoint connected to a second end, different from the first end, of the secondary winding S of transformer T.

[0039] In general, each switch G1 A, G1 B, G2A, G2B, G3A, G3B, G4A, G4B can be, for example, a transistor, such as a metal-oxide-gate field-effect transistor (MOSFET), a silicon metal-oxide-gate field-effect transistor (SiMOSFET), a silicon carbide metal-oxide-gate field-effect transistor (SiCMOSFET), an insulated-gate bipolar transistor (IGBT), or a gallium nitride field-effect transistor. Gallium Nitride Field Effect Transistor (also known by the acronym GaN FET).

[0040] Switches G1A, G1B, G2A, G2B, G3A, G3B, G4A, and G4B are each controlled to open and close by commands C1 from control device 108. These commands are transmitted, for example, via a grid driver. Each grid driver is, for example, electrically powered by a power supply. For readability, only the The gate driver PG1A and the power supply A1A of transistor G1A are shown in Figure 2.

[0041] With reference to Figure 3, an example of a method 300 for operating the control device 108 will now be described.

[0042] During step 302, the electrical installation 102 operates normally. In particular, the control device 108 provides the commands C1 to switch the switches G1A, G1B, G2A, G2B, G3A, G3B, G4A, and G4B. In each switching arm B1, B2, B3, and B4, the two switches are switched in opposition: one open while the other is closed. A dead time is generally provided to prevent both switches in the same switching arm from being closed simultaneously.

[0043] During an optional step 304, the safety device 110 detects a failure of the source SC1, for example a failure of the DCDC1 converter.

[0044] During a step 306, for example while the source SC1 is still detected as faulty when step 304 is implemented, the safety device 110 detects a supply of electrical power from the LV1 network, for example an overvoltage and / or a reverse current 11.

[0045] In response, during a step 308, the control device 108 short-circuits the connection L1 to electrical ground GND2. For example, the safety device 110 commands the closing of both switches of at least one of the switching arms B3, B4 of the conversion stage EC2.

[0046] During a step 310, the control device 108 detects that the voltage VB1 is very low, almost zero, for example below a predefined threshold.

[0047] In response, during a step 312, the control device 108 stops the source SC1, for example the DCDC1 converter.

[0048] With reference to Figure 4, another example of the implementation of electrical installation 102 will now be described.

[0049] Electrical installation 102 this time includes first and second DC voltage sources, hereafter referred to as sources SC1 and SC2, designed to provide DC voltages VB1, VB2 respectively.

[0050] For example, the first source SC1 includes a first battery BAT1 designed to provide a DC voltage VBATI and a first converter of DC-DC voltage converter DCDC1 is designed to convert the DC voltage VBATI into the DC voltage VB1. Similarly, the second source SC2 includes a second battery BAT2 designed to provide a DC voltage VBAT2 and a second DC-DC voltage converter DCDC2 designed to convert the DC voltage VBAT2 into the DC voltage VB2.

[0051] The DC voltages VBATI, BAT2 are for example equal to each other, for example equal to 400V.

[0052] For example, batteries BAT1 and BAT2 consist of cells or accumulators connected in series. For example, the cells in batteries BAT1 and BAT2 are lithium-ion cells, lithium iron phosphate (LFP) cells, or lithium nickel manganese cobalt (NMC) cells. For example, batteries BAT1 and BAT2 have the same number N of cells or accumulators connected in series. Alternatively, batteries BAT1 and BAT2 can have a different number of cells or accumulators connected in series.

[0053] The first and second batteries BAT1, BAT2 are, for example, connected in series with each other, so as to form a battery system designed to provide a so-called overall DC voltage, for example a high voltage, for example 800V, from the voltages VBATI, VBAT2, for example the sum of the voltages VBATI, VBAT2-

[0054] In other embodiments, the two sources SC1 and SC2 can share a single battery providing a DC voltage. In this case, the two DC-DC converters DC1 and DC-DC2 are connected to this shared battery to receive the DC voltage supplied by it.

[0055] The battery system, for example, is designed to electrically power the electric motor 106 illustrated in Figure 1 from the overall DC voltage.

[0056] Furthermore, the electrical installation 102 also includes a first network LV1 designed to be powered by a DC voltage V1, and a second network LV2 designed to be powered by a DC voltage V2. The voltages V1 and V2 of the networks LV1 and LV2 are, for example, low voltages. Also, for example, the voltages V1 and V2 are equal.

[0057] The second LV2 network includes a BAT battery and Z2 equipment, while the first LV1 network is preferably battery-free, but includes Z1 equipment.

[0058] The BAT battery is designed to be charged from the SC1 and SC2 power sources supplying the LV1 network, and to power the Z1 equipment of this LV1 network itself. For this purpose, the BAT battery is designed, for example, to store enough electrical energy to deliver 1 kW for two minutes.

[0059] When it is stated that the first LV1 network is battery-free, this means at a minimum that it lacks a battery designed to power the Z1 equipment of the LV1 network and / or capable of storing enough electrical energy to deliver 1 kW for two minutes. Thus, the LV1 network may include electrical components that are not batteries within the meaning of the present invention.

[0060] For example, the overall DC voltage (VBATI + V B AT2) is referenced with respect to a first ground GND1, while the voltages VB1, VB2, V1, V2 are referenced with respect to a second ground GND2, different from the first ground GND1.

[0061] The 100 mobility vehicle also includes an IT interconnection device designed to connect SC1, SC2 sources to LV1, LV2 networks, according to different configurations.

[0062] The IT interconnection device further includes a first L1 link between the first source SC1 and the first network LV1. This first L1 link includes an upstream switch S11 connected between the first source SC1 and the first network LV1.

[0063] The IT interconnection device first includes a second L2 link between the second source SC2 and the second network LV2. This second L2 link includes second upstream switches S21 and downstream switches S22 connected to each other at a first midpoint P2. The second upstream switch S21 is connected between the second source SC2 and the second downstream switch S22, while the latter is connected between the second upstream switch S21 and the second network LV2.

[0064] The IT interconnection device further includes a junction switch BP connected between the first and second links L1, L2, and more precisely between a first midpoint P1 located between the first upstream switch S11 and the first network LV1 and the second midpoint P2.

[0065] The first link L1 may also include a first downstream switch connected between the first midpoint P1 and the first network LV1. The first upstream switches S11 and downstream switches are then connected to each other at the first midpoint P1.

[0066] The controllable switches S11, S21, and S22 are, for example, unidirectional switches designed, when open, to interrupt current in only one direction, but not in the other. More precisely, each upstream switch S11, S21 is designed to interrupt the current flowing from the midpoint P1, P2 to the source SC1, SC2 that it connects. Furthermore, each downstream switch S22 is designed to interrupt the current flowing from the midpoint P1, P2 to the network LV1, LV2 that it connects.

[0067] For example, each controllable switch S11, S12, S21 is a semiconductor switch, such as a transistor, for example a metal-oxide-gate field-effect transistor (MOSFET), a silicon metal-oxide-gate field-effect transistor (SiMOSFET), a silicon carbide metal-oxide-gate field-effect transistor (SiCMOSFET), an insulated-gate bipolar transistor (IGBT), or a gallium nitride field-effect transistor. the acronym GaNFET). The semiconductor switches used generally have an intrinsic diode or a parallel diode. In this case, the diode conducts towards the respective midpoint P1, P2 (cathode connected to the respective midpoint P1, P2).

[0068] The junction switch BP is preferably a bidirectional switch designed to interrupt current in both directions when open. The junction switch BP comprises, for example, two unidirectional switches BP1 and BP2 arranged back-to-back in series, with, for example, an inductance L between them. Indeed, if a fault occurs on one of the two connections L1 and L2, the presence of the inductance L can slow the propagation of this fault to the other connection. This inductance L can be omitted, so that the switches Unidirectional switches BP1 and BP2 are directly connected to each other. Switch BP1 is connected to the midpoint P1, while switch BP2 is connected to the midpoint P2. These unidirectional switches BP1 and BP2 are, for example, semiconductor switches, as detailed above, generally featuring an intrinsic diode or one added in parallel. In this case, the diodes are reverse-biased, meaning either each conducts towards the other (cathodes connected to each other), or each blocks current towards the other (anodes connected to each other, as in the illustrated example).

[0069] The DCDC1 converter is for example as illustrated in Figure 2 and the process of Figure 3 can be implemented with the electrical installation 102 of Figure 4, except that, in certain embodiments, following the detection of failure in step 304, even before detection of electrical power supply by the LV1 network, the safety device 110 commands the opening of the junction switch BP to isolate the two links L1, L2.

[0070] In conclusion, it should be noted that the invention is not limited to the embodiments described above. Indeed, it will be apparent to those skilled in the art that various modifications can be made to the embodiments described above, in light of the information just provided.

[0071] In the detailed presentation of the invention given above, the terms used shall not be interpreted as limiting the invention to the embodiments set forth in this description, but shall be interpreted as including all equivalents which can be foreseen by a person skilled in the art by applying their general knowledge to the implementation of the teaching which has just been disclosed to them.

Claims

Demands [1] Electrical installation (102) for a mobility device (100), comprising: a source (SC1) designed to supply a DC voltage (VB1) with respect to an electrical ground (GND2); a network (LV1) without a battery and connected to the electrical ground (GND2); and a link (L1) connecting the DC voltage source (SC1) to the network (LV1); characterized in that it further comprises: at least one short-circuit switch (G3A, G3B; G4A, G4B) between the link (L1) and the electrical ground (GND2); and a safety device (110) designed to, in response to the detection of an electrical power supply from the network (LV1) on the link (L1), control the closing of each short-circuit switch (G3A, G3B; G4A, G4B) to evacuate the power supplied from the network (LV1) to the electrical ground (GND2). [2] Electrical installation (102) according to claim 1, wherein the detection of the supply of electrical power by the network (LV1) on the link (L1) includes the detection of an overvoltage of a voltage (VB1) from the network (LV1) and / or a reverse current (11) leaving the network (LV1) towards the source (SC1). [3] Electrical installation (102) according to claim 1 or 2, wherein the source (SC1) is an AC-DC converter (EC2) comprising at least one switching arm (B3; B4) between the link (L1) and the electrical ground (GND2), comprising two switches connected (G3A, G3B; G4A, G4B) to each other at a midpoint, and wherein the switching arm (B3; B4) forms the short-circuit switch (B3; B4). [4] Electrical installation (102) according to claim 3, wherein the AC-DC converter (EC2) comprises two switching arms (B3, B4) forming respectively two short-circuit switches (B3, B4). [5] Electrical installation (102) according to any one of claims 1 to 4, wherein the safety device (110) is designed to control the closing of each short-circuit switch in response to the detection of a fault from the source (SC1), at the same time as the detection of the supply of electrical energy by the network (LV1) on the link (L1). [6] Electrical installation (102) according to any one of claims 1 to 5, wherein the safety device (110) is designed to, in response to a detection that a voltage (VB1) on the link (L1) is below a predefined threshold, deactivate the source (SC1). [7] Mobility device (100) comprising an electrical installation (102) according to any one of claims 1 to 6. [8] Method (300) of evacuating energy supplied by a network (LV1) without a battery on a link (L1) connecting a DC voltage source (SC1) to the network (LV1), the DC voltage source (SC1) and the network being connected to an electrical ground (GND2), comprising: a detection of the supply of electrical energy by the network (LV1) on the link (L1); and in response, a command to close at least one short-circuit switch (G3A, G3B; G4A, G4B) located between the link (L1) and the electrical ground (GND2), to evacuate the energy supplied by the network (LV1) to the electrical ground (GND2). [9] A computer program downloadable from a communication network and / or stored on a computer-readable medium, characterized in that it includes instructions for carrying out the steps of a process according to claim 8, when said program is executed on a computer.

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