Electric motor vehicle

Abstract

The invention relates to an electric motor vehicle (100) with a high-voltage traction battery (10) and a high-voltage traction motor (32) supplied with high-voltage direct current (HDC) by the high-voltage traction battery (10), a bidirectional mains voltage connection box (60) and a bidirectional mains voltage high-voltage converter arrangement (50) electrically connected to the mains voltage connection box (60), which has a DC / AC converter (52) and a separate AC / DC converter (54), a mains voltage consumer (58) which is supplied with mains alternating voltage (AC) by the mains voltage high-voltage converter arrangement (50), and an energy control (40) informationally connected to the mains voltage high-voltage converter arrangement (50).

Description

The invention relates to an electromotive motor vehicle having a high-voltage traction battery and a high-voltage traction motor which is supplied with high-voltage DC voltage by the high-voltage traction battery.In an electric motor vehicle, a separate low-DC voltage grid with a rated voltage of, for example, 12 V or 24 V is generally provided for supplying secondary electrical assemblies with electrical energy, since this offers considerable advantages over secondary electrical assemblies with high-voltage DC voltage, in particular because of the high availability of secondary electrical 12V or 24V direct current assemblies and because of the lower safety requirements.However, the power requirement of certain secondary electrical assemblies is considerable and can lie in the single-digit and even low two-digit kW range, for example in the case of electric air-conditioning compressors, electric heaters, pumps, etc. Because of the high electric currents, the line cross sections must then be designed to be very large.WO 2018 013 036 A1 and CN 105 799 515 A each disclose an electromotive motor vehicle having a high-voltage DC voltage circuit and having a separate AC voltage circuit which is operated with mains AC voltage of, for example, 220 V or 110 V AC voltage. However, a separate DC / AC converter is also required for this purpose, which transforms the high-voltage DC voltage into a mains AC voltage.DE 10 2021 205 265 A1 discloses an electric motor vehicle having a unidirectional mains voltage connection socket and a socket for connecting a mains voltage load.DE 10 2016 117 729 A1 discloses an electric motor vehicle which, in addition to the charging electronics for feeding the traction battery, has a separate inverter for supplying a socket with mains AC voltage.DE 10 2020 204 336 A1 discloses an electric motor vehicle having a high-voltage converter arrangement.The object of the invention is to provide an electric motor vehicle with a versatile electrical architecture.This object is achieved according to the invention by an electric motor vehicle having the features of claim 1.The electromotive motor vehicle according to the invention has a high-voltage traction battery and a traction motor which is fed by the high-voltage traction battery with its high-voltage DC voltage. In the present case, a high-voltage DC voltage is understood to mean, in principle, a DC voltage of more than 60 V, in particular of more than 250 V. For the high-voltage DC voltage grid of the motor vehicle, costly safety measures are required both for the electrical insulation and for a fault case.The motor vehicle is equipped with a bidirectional mains voltage connection box and a mains voltage-high voltage converter arrangement which is electrically connected to the mains voltage connection box and is likewise bidirectional and has a DC / AC converter and an AC / DC converter. The AC / DC converter converts the mains AC voltage coming from the mains voltage connection box into the high-voltage DC voltage of the high-voltage traction battery in order in this way to be able to charge the high-voltage traction battery with electrical energy from the public electrical supply network via the mains voltage connection box, for example via a so-called wallbox.The DC / AC converter serves to generate the grid AC voltage from the high-voltage DC voltage of the high-voltage traction battery, so that electrical energy can be fed from the high-voltage traction battery into the public electrical supply grid. In this way, when there is a high demand for electrical energy, the public supply grid can temporarily obtain it from the high-voltage traction battery of the electric motor vehicle when the latter is connected to the public electric supply grid, for example via a bidirectional wallbox.The motor vehicle has at least one mains voltage consumer which is fed with mains AC voltage by the mains voltage-high voltage converter arrangement. Furthermore, an electronic energy control is provided, which is connected in information terms to the mains voltage-high voltage converter arrangement, for example via a physical data connection. The energy controller controls the mains voltage-high voltage converter arrangement in such a way that, if necessary, the mains voltage consumer is selectively supplied with electrical energy from the DC / AC converter or directly from the mains voltage connection box.The mains voltage-high voltage converter arrangement is thus designed bidirectionally and allows electrical energy to be fed into the public electrical supply grid when the mains voltage connection box is connected to the public electrical supply grid. In this case, the DC / AC converter converts the electrical energy from the high-voltage traction battery into the mains AC voltage of the public electrical supply grid. The same DC / AC converter is used to convert electrical energy from the high-voltage traction battery into mains AC voltage if required in order to supply the mains voltage load on the vehicle with electrical energy. The DC / AC converter thus has a dual function and is not used exclusively for bidirectional charging and discharging, but also for supplying the mains voltage load with electrical energy if the mains voltage connection box is not connected to the public electrical supply grid.The energy controller is designed such that, in a discharging mode in which electrical energy is fed from the high-voltage traction battery into the public electrical supply grid, it actuates the grid voltage-high-voltage converter arrangement such that not only the grid voltage connection box but also the grid voltage consumer are supplied with electrical energy from the DC / AC converter.Preferably, a separate DC voltage converter is provided in the electrical grid of the motor vehicle, which is fed by the high-voltage traction battery and supplies a low DC voltage for a low DC voltage consumer. The low DC voltage can be, in particular, a classic motor vehicle DC voltage in the low-voltage range of at most 60 V, in particular the typical low DC voltage of 12 V or 24 V. Only relatively small safety measures are required for these low DC voltages and many electrical units are available.The low-DC voltage loads preferably have a power of at most 1.0 kW, particularly preferably of at most 0.5 kW. Correspondingly, the mains voltage loads have a voltage of more than 1.0 kW, or particularly preferably of more than 0.5 kW. In this way, the network can be designed for the low DC voltage with relatively low cross sections.Preferably, the energy controller controls the mains voltage-high voltage converter arrangement during a driving operation in such a way that the mains voltage consumer is supplied with electrical energy from the DC / AC converter.The energy controller is preferably designed such that, in an AC charging mode, it actuates the mains voltage-high-voltage converter arrangement such that the mains voltage consumer is supplied with electrical energy from the mains voltage connection box. This can be useful, for example, for electric interior heating and for typical camping devices, such as a refrigerator.An exemplary embodiment of the invention is explained in more detail below with reference to the FIGURE. FIG. 1 shows a schematic illustration of an electric motor vehicle having a high-voltage traction battery, a mains voltage-high-voltage converter arrangement and an energy controller which controls the mains voltage-high-voltage converter arrangement.FIG. 1 schematically illustrates an electromotive motor vehicle 100 having a high-voltage traction battery 10 and a high-voltage traction motor 32 fed by the high-voltage traction battery 10 with high-voltage DC voltage HDC. The high-voltage traction battery may have a capacity of over 10 kWh and, in the case of a so-called fully electric motor vehicle, has a capacity of the order of magnitude of 100 kWh and higher. The high-voltage traction battery has a high-voltage DC voltage as system voltage of far more than 100 V, for example of typically 400 V or 800 V.The high-voltage traction motor 32 is controlled by power electronics 30 which have electronic commutation and are fed directly by the high-voltage traction battery 10 with the high-voltage DC voltage HDC.The electric motor vehicle 100 further has a separate DC voltage converter 20, which is fed by the high-voltage traction battery 10 and which provides a low DC voltage LDC for a low DC voltage consumer 22. A typical low DC voltage is 12 V or 24 V. The low DC voltage consumer 22 or all DC voltage consumers 22 in the present case each have a power of at most a few 100 watts. Typical examples of small DC voltage consumers 22 are actuating drives, small fluid pumps, control electronics, entertainment electronics, etc.The motor vehicle 100 has a mains voltage-high voltage converter arrangement 50, which is connected to a mains voltage connection box 60 of the motor vehicle 100. The mains voltage-high voltage converter arrangement 50 has an AC / DC converter 54 which serves to convert a mains AC voltage AC present at the mains voltage connection box 60 into the high voltage DC voltage HDC, in order in this way to charge the high voltage traction battery 10 with electrical energy when the mains voltage connection box 60 is connected to a mains voltage connection plug 72, which is fed with electrical energy from a public electrical supply network 70. The mains AC voltage AC can be, for example, 110 V or 220 V and have a mains frequency of 50 or 60 Hz.Furthermore, the grid voltage-high voltage converter arrangement 50 has a separate DC / AC converter 52, which transforms the high voltage DC voltage HDC of the traction battery 10 into the grid AC voltage AC as required. This is offered on the one hand in a stationary discharging mode when the mains voltage connection box 60 is electrically connected to the mains voltage connection plug 72 and electrical energy is to be fed into the public electrical supply network 70. Furthermore, the DC / AC converter 52 converts electrical energy in the form of the high-voltage DC voltage HDC of the high-voltage traction battery 10 into grid AC voltage AC as required even during the driving operation, in order in this way to supply a grid voltage consumer 58 with electrical energy with grid AC voltage AC during the driving operation. The mains voltage load 58 typically has a power of more than a few 100 watts, and can have a maximum power in the low 2-digit kW range. Typical examples of a mains voltage consumer 58 are an air conditioning compressor, a coolant pump, an interior heating system and a typical camping unit, for example a coffee machine, a refrigerator or a service water heating system.Finally, the high-voltage converter arrangement 50 has a mains voltage switch 56, which is electrically connected to the mains voltage connection box 60, the AC / DC converter 54, the DC / AC converter 52 and the mains voltage load 58. The mains voltage switch 56 can connect the mains voltage connection box 60 in charging operation to the input of the AC / DC converter 54 and, if necessary, to the mains voltage load 58, in discharging operation to the output of the DC / AC converter 52 to the mains voltage connection box 60 and, if necessary, to the mains voltage load 58, and finally, in driving operation, to the output of the DC / AC converter 52 exclusively to the mains voltage load 58.An electronic energy controller 40 is provided, which is connected in information terms via data lines to the DC / AC converter 52, the AC / DC converter 54, the mains voltage switch 56, the mains voltage load 58, the motor power electronics 30, the DC converter 20, and the low-DC voltage load 22. The electronic energy controller 40 controls the units connected to it in the charging mode, in the discharging mode and in the driving mode, for example, in the manner already described above.

Claims

Electromotive motor vehicle (100) having a high-voltage traction battery (10) and a high-voltage traction motor (32) which is fed by the high-voltage traction battery (10) with high-voltage DC voltage (HDC), a bidirectional mains voltage connection box (60) and a bidirectional mains voltage-high-voltage converter arrangement (50) which is electrically connected to the mains voltage connection box (60) and has a DC / AC converter (52) and an AC / DC converter (54), the AC / DC converter converting the mains AC voltage coming from the mains voltage connection box (60) into the high-voltage DC voltage (HDC) of the high-voltage traction battery (10), and the DC / AC converter generates the mains AC voltage (AC) from the high-voltage DC voltage (HDC) of the high-voltage traction battery (10), such that electrical energy is fed from the high-voltage traction battery (10) via the mains voltage connection box (60) into a public electrical supply grid (70), a mains voltage consumer (58) which is fed with mains AC voltage (AC) by the bidirectional mains voltage-high-voltage converter arrangement (50), and an energy controller (40) which is connected in information terms to the mains voltage-high-voltage converter arrangement (50), wherein the energy controller (40) controls the bidirectional mains voltage-high-voltage converter arrangement (50) in such a way in a discharging mode, supplying the mains voltage load (58) with electrical energy from the DC / AC converter (52).Electromotive motor vehicle (100) according to Claim 1, wherein a separate DC voltage converter (20) is provided, which is fed by the high-voltage traction battery (10) and supplies a low DC voltage (LDC) for a low DC voltage consumer (22).Electromotive motor vehicle (100) according to one of the preceding claims, wherein the energy controller (40) controls the mains voltage-high-voltage converter arrangement (50) in a driving mode in such a way that the mains voltage consumer (58) is supplied with electrical energy from the DC / AC converter (52).Electromotive motor vehicle (100) according to one of the preceding claims, wherein the energy controller (40) controls the mains voltage-high-voltage converter arrangement (50) in an AC charging mode in such a way that the mains voltage consumer (58) is supplied with electrical energy from the mains voltage connection box (60).

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