Power circuit for supplying power in an electrically powered vehicle

Abstract

Power circuit (10) for power supply in an electrically powered vehicle, wherein the power circuit (10) comprises: - a DC voltage connection (20); - at least one DC-AC converter (40) having an AC side (42); and - at least one DC-DC converter (50) with two converter sides (52, 54), wherein the first converter side (52) is connected via a junction point (60) to a DC voltage side (44) of the DC-AC converter (40) and the DC voltage connection (20) is likewise connected to this junction point (60), wherein the power circuit (10) further comprises an energy storage connection (82), wherein the second converter side (54) of the DC-DC converter (50) is connected to the energy storage connection (82), which is provided for connecting a vehicle-side energy storage device (80), wherein the power circuit (10) is equipped with a changeover switch that controllably connects the DC voltage connection (20) either to the junction point (60) or to the energy storage connection (82) and / or to a selection circuit (31) that selectably connects the DC-AC converter (40) to an electric machine (30) or a connection thereto, with an internal AC power connection (74),connects to an external AC voltage connection (70) and / or to a coil for inductive power transfer.

Description

[0001] The invention relates to the field of electromobility and in particular to the connection or functional integration of corresponding vehicles into electrical supply networks.

[0002] The components of an electric mobility system are typically limited to the use of only one type of current (i.e., alternating current or direct current). Alternating current is necessarily required to generate a rotating electromagnetic field, especially when using non-commutating electric machines, whereas storing electrical energy in a battery or generating electrical energy using photovoltaics requires the use of direct current.

[0003] Document US 5,504,414 A shows an onboard electrical system in which a battery is connected to an inverter. The connection between the inverter and an electric motor includes feed points for connection to an external power supply.

[0004] Document JP 2010-041 819 A depicts a photovoltaic system. The photovoltaic cells of the system are connected via a DC / DC converter to a subsequent inverter, which in turn is connected to an AC power grid. The connection point between the DC / DC converter and the inverter is connected via another DC / DC converter to a vehicle charging port.

[0005] Document US 2013 / 0 020 993 A1 describes a variable vehicle charging system with an energy source that leads to a first charging port via a DC / DC converter and to a second charging port via an inverter.

[0006] Document US 2016 / 0152129A1 describes a vehicle electrical system with two electric motors, each with its own upstream inverter. The inverters are connected via a DC / DC converter. The converter also connects a battery to a charging port.

[0007] Document US 2009 / 0153097A1 shows a battery connected to an electric motor via an inverter. The electric motor has a switchable neutral point. An AC power source can be connected to the neutral point.

[0008] The publication DE 10 2008 063 465 A1 describes an operating arrangement of an electric vehicle. A battery is connected to an electric motor via a DC-DC converter and a subsequent inverter. Switches are provided that connect the inverter either to the electric motor or to an AC charging port.

[0009] When coupling these different components, the type of current (or voltage level) must be changed, which necessitates complex power electronic actuators for converting electrical energy ("energy converters"), and these are associated with high costs. Furthermore, coupling different types of current requires expensive electronic power components for control.

[0010] The object of the invention is therefore to demonstrate a way in which components of such a system can be connected to each other with less effort. Disclosure of the invention

[0011] This task is solved by the power circuit and by the stationary power supply system in accordance with the independent requirements.

[0012] It is proposed to use a DC power connection for connecting external equipment (such as a DC power supply network, or an island grid like that of a solar power plant), which is connected to a junction point that connects a DC-DC converter and a DC-AC converter. The DC-DC converter and the DC-AC converter are preferably located within a vehicle; in particular, the DC power connection is on the vehicle side. The DC-AC converter is preferably an inverter, in particular a traction inverter, i.e., an inverter connected to an electric machine or a connection thereto, wherein the electric machine drives the vehicle's wheels. The DC-AC converter can generally be an inverter of an electric machine, in particular of a motor (such as an internal combustion engine starter or a starter / generator), or the inverter of an electric machine of a compressor (such as an air conditioning compressor or a compressor of an internal combustion engine turbocharger).

[0013] Furthermore, the DCAC converter can be an inverter of a charging device. The charging device is formed by the DCDC converter, as shown, for example, with reference numeral 50 in the figure, and the DCAC converter, as shown, for example, with reference numeral 40 in the figure. Alternatively, the DCAC converter itself can implement the charging device (particularly without an additional converter), with energy storage devices being charged via the DC side of the DCAC converter, for example, via the DC connection. This latter variant enables the transfer of energy from a vehicle-side electrical energy storage device to a stationary DC network.

[0014] The DC-DC converter can be a converter of a charging device or a converter for the DC-AC converter, which in turn is configured for connecting an electric motor. Specifically, the DC-DC converter can be a converter of a charging device that is connected to the connection point or to the DC-AC converter.

[0015] One or more DC-DC converters and / or one or more DC-AC converters can be connected to the interface point. The DC-AC converter is specifically designed to convert a direct current (also called DC current) or a direct voltage (also called DC voltage) into an alternating current (also called AC current) or an alternating voltage (also called AC voltage). Preferably, the DC-AC converter is also designed for the reverse direction. In this case, it is referred to as a bidirectional converter.

[0016] The DC-DC converter is preferably a converter of a charging device. The interface of the DC-DC converter is connected to an electrical energy storage device to be charged (stationary or vehicle-mounted), or to a connection for this purpose (especially in the case of a stationary energy storage device). Furthermore, the power circuit can include an electric motor or a connection for this purpose. In this case, the AC side of the DC-DC converter is connected to the electric motor or to the connection for this purpose. The DC-DC converter thus acts as an inverter for the electric motor.

[0017] By feeding power into such a central point, namely the junction of the DC-DC converter and the DC-AC converter (or rather, its DC side), numerous components can be used effectively. A power circuit is proposed that is both bidirectional (thus using the same components for different functions) and serves both charging and traction purposes. In particular, the DC-DC converter can be used bidirectionally, so that its components can be used both for charging an energy storage device (especially one on the vehicle side) and for discharging, i.e., drawing power to operate a traction drive. Furthermore, the DC-DC converter can be unidirectional, i.e., configured to transfer electrical energy from the DC input to a (vehicle-side) energy storage input.The DCDC converter can therefore be configured to receive and convert electrical energy from the DC voltage connection, with the DCDC converter being designed to be unidirectional or bidirectional.

[0018] Furthermore, an (additional) AC connection (also known as an alternating current connection) can easily be integrated, with the integration requiring no additional components other than potentially necessary filters and / or selection switches. It is therefore possible to use both AC power (e.g., from a general power grid) and DC power (e.g., from a photovoltaic system or other DC off-grid) simultaneously to charge the electrical energy storage system. An automatic selection mechanism can be provided, configured to detect the voltage applied to the connections in order to raise or lower the voltage at the connection point according to the desired energy flow, or to adjust the inverter's operating parameters accordingly.In particular, the automatic selection function can be configured to detect whether one or more phases of an AC voltage signal are present at the AC connection, in order to adjust the inverter (on the input side) accordingly. This significantly simplifies the connection, while allowing multiple connection types (AC or DC) to be used simultaneously or selectively.

[0019] This document describes a power supply circuit for an electrically powered vehicle, which is specifically integrated into the vehicle's electrical system. The power supply circuit includes a DC connection, which can be connected to an electrical coupling on the exterior of the vehicle, allowing external electrical contact with the power supply circuit. The DC connection is used to charge the vehicle, but energy can also flow in both directions through the DC connection, for example, when the vehicle's traction battery is used to support a connected stationary power supply network (island grid or public grid). The DC connection is designed according to a standard, such as IEC 60309 or IEC 62196 (equivalent to DIN EN 62196), or according to a CENELEC standard for charging plugs or sockets.

[0020] The DC and, if applicable, the AC connections have resistive contacts. Instead of, or in combination with, a cable-based interface, an inductive interface may be provided. This inductive interface may include a (vehicle-side) secondary coil of an inductive charging device. The inductive interface may be connected to the AC connection or to the DC connection via its own inverter and / or rectifier. The secondary coil may be located within a resonant circuit, i.e., it may be connected to a capacitor to form the resonant circuit. A smoothing capacitor may be connected downstream of the secondary coil (generally: coil for inductive power transfer) to generate DC voltage, particularly when connected to the DC connection.If both resistive contacts (of the electrical coupling) in the sense of a resistive interface and an inductive interface are provided, the DC voltage connection or the AC connection (preferably together) includes a (common) changeover switch (corresponding to a selection circuit) or a combination circuit for connecting the two interfaces in order to connect both interfaces selectably or together to a connection point, which will be explained in more detail below. An automatic charging circuit may be provided that disconnects the relevant connection (DC voltage connection, AC connection; connection of the cable-related interface, connection of the secondary coil) when no voltage is present at the relevant connection, or that connects the live connections.

[0021] The (resistive) DC voltage connection can be designed for an operating voltage of more than 60 V and in particular up to 600 V, 800 V or 1200 V. Alternatively, the DC voltage connection can also be configured for nominal voltages of 12 V, 24 V or 48 V.

[0022] The power circuit further comprises an electric machine, in particular an electric traction drive, a starter / generator, an electric machine of an (air conditioning or charging) compressor or at least a connection that is equipped for connection to an electric machine.

[0023] One embodiment provides that the electric machine corresponds to a traction drive. This is connected to the vehicle's wheels via power transmission. The traction drive serves to propel the vehicle, either alone or in combination with at least one other drive unit, such as an internal combustion engine. The traction drive comprises the aforementioned electric machine, which may optionally be configured to also operate as a generator, for example, to recuperate the vehicle's kinetic energy. It may be a separately excited (or optionally a permanent magnet) DC motor, a synchronous machine (three-phase synchronous machine or single-phase synchronous machine), or an asynchronous machine. However, a separately excited synchronous machine is preferably used, in particular a separately excited three-phase synchronous machine.

[0024] The traction drive, or more generally the electric machine, is preferably designed for an operating voltage greater than 60 V, and in particular up to 350 V, 400 V, 600 V, 800 V or 1200 V. Alternatively, the traction drive can be designed for nominal voltages of 12 V, 14 V, 24 V, 36 V, 42 V or 48 V.

[0025] Furthermore, as mentioned, the power circuit is equipped with a DC-AC converter, in particular an inverter, which is connected to the traction drive (or to another electric machine), specifically to the stator phases of the traction drive or the electric machine. The inverter or DC-AC converter can be a traction inverter, or it can be an inverter of a motor (e.g., an internal combustion engine starter or a starter / generator of an internal combustion engine) or the inverter of a compressor (e.g., an air conditioning compressor or a compressor of an internal combustion engine turbocharging system). The inverter can be configured as a PFC inverter (PFC - Power Factor Correction) or a B6C inverter. The inverter is preferably multi-phase and includes semiconductor switching devices. These can be configured, for example, as a B2 bridge or a B6C bridge (generally: BnC with n = 2 * number of phases) or as an H-bridge.The inverter's switching elements can be configured as IGBTs, preferably with parallel diodes, or MOSFETs. A preferred embodiment uses SiC semiconductor line switches. This allows the inverter to also be used to generate alternating currents for exciting a coil for inductive power transmission. The semiconductor switching devices are preferably configured for a switching frequency of up to 20 kHz, with the maximum switching frequency of the semiconductor switching devices (e.g., MOSFETs) preferably being up to 100 kHz or, more preferably, up to 200 kHz.

[0026] The DC-AC converter (or inverter), and in particular its AC side, is either directly connected to the traction drive or, more generally, to a downstream electric machine or to an AC power supply. Alternatively, a selector circuit is provided that allows the inverter (in particular its AC side) to be selectively connected to an electric machine, an internal AC power supply, an external AC power supply, and / or a coil for inductive power transfer (or a corresponding coil connection). The inverter, and in particular its AC side, can therefore be connected to the traction drive or, more generally, to an electric machine via a selector circuit, whereby the selector circuit connects the inverter (or its AC side) selectively to the traction drive (more generally: electric machine), to the resistive interface, to the inductive interface (in particular the coil or a corresponding coil connection).whose coil connection) and / or with a vehicle-side mains socket (in the sense of the internal AC voltage connection) as an internal interface (i.e., for components within the vehicle). The resistive interface and the inductive interface can be considered external interfaces. According to a first embodiment, the selection circuit connects the AC-DC converter (especially its AC side) to only one of these components at a time (traction drive or, more generally, electric machine, inductive interface, resistive interface, vehicle-side mains socket). According to a second embodiment, the selection circuit connects the inverter to one or more of the aforementioned components. The second embodiment provides, in particular, that the selection circuit connects the inverter either to the traction drive (or, more generally, the inductive interface, resistive interface, or vehicle-side mains socket).generally connected to an electric machine) or to one or more of the aforementioned (internal or external) interfaces. This selection circuit, which allows multiplexing with respect to the inverter's use, can be used to connect an AC signal. (i) for the operation of the traction drive (general: of an electric machine) (ii) for the (bidirectional) exchange of energy between a vehicle-side electrical energy storage system and an AC supply network / island grid via an AC connection or (iii) to generate and selectively transmit power from a vehicle-side electrical energy storage system into a DC power supply network (island network) via the inductive or resistive interface.

[0027] This gives the traction inverter additional functions, which are implemented with the given components. The vehicle's mains socket is designed like mains sockets for connecting electrical devices to the lowest distribution level of a low-voltage public power grid, for example according to the NEMA or CEE standards. The vehicle's mains socket is typically single-phase, but can also be multi-phase (three-phase).

[0028] The traction inverter is preferably designed for an operating voltage greater than 60 V, and in particular up to 350 V, 400 V, 600 V, 800 V, or 1200 V. Alternatively, the traction inverter can also be designed for an operating voltage of 12 V, 14 V, 24 V, 36 V, 42 V, or 48 V. The traction inverter is particularly bidirectional and can therefore transfer power from the AC side to a DC side of the traction inverter, as well as transfer power in the reverse direction.

[0029] The power circuit further comprises a DC-DC converter with two converter sides. The DC-DC converter is preferably bidirectional. The converter sides can be high-voltage converter sides. "High voltage" means that the components in question are designed for operating voltages of more than 60 V and, in particular, up to 350, 400, 600, 800 V, or 1200 V. However, the converter sides can also be designed for operating voltages of 12 V, 14 V, 24 V, 36 V, 42 V, or 48 V. The first of the two converter sides is connected to a DC side of the traction inverter via a junction (of the power circuit). The junction is provided in a preferably two-wire connection between the traction inverter (DC side) and the first converter side of the DC-DC converter.The two-wire connection can be designed as a high-voltage connection, particularly for an operating voltage of more than 60 V or 200 V, and especially up to 400 V, 600 V, 800 V, or 1200 V. Alternatively, the two-wire connection is designed for an operating voltage of 12 V, 14 V, 24 V, 36 V, 42 V, or 48 V. The DC connection is preferably also connected to this connection or the junction point. This allows external DC power to be fed directly into the DC-DC converter without conversion, for example, to charge a vehicle-mounted electrical energy storage device. Similarly, recuperation power from the traction drive (in generator mode) can be routed through the traction inverter to the DC-DC converter, which can then supply the power as DC voltage to an electrical energy storage device for charging.Therefore, no external chargers are necessary when charging with direct current, as the converter already used for transferring recuperated power can also perform this function. However, this does not preclude the use of an additional charger. If the DC-DC converter is bidirectional, its components can be used to implement further functions, as will be explained in more detail later in this description.

[0030] According to one embodiment, the power circuit has an energy storage connection. The second converter side of the DC-DC converter is connected to the energy storage connection (preferably directly). The energy storage connection is configured to be connected to a vehicle-side electrical energy storage device. The energy storage device is, in particular, a high-voltage energy storage device, such as a high-voltage traction battery (or a capacitor bank, or a combination of a capacitor bank and a traction battery) located in the vehicle. Instead of an energy storage connection, the power circuit can also include the energy storage device itself, which is connected to the second converter side of the DC-DC converter.

[0031] Another embodiment of the power circuit provides that the DC-DC converter is configured for bidirectional energy transfer between the two converter sides, i.e., between the first converter side and the second converter side. The DC-DC converter is specifically designed as a synchronous converter. This enables the power circuit to selectively draw power from or supply power to the energy storage device via the DC-DC converter. The energy storage device can be charged via the DC-DC converter, as well as via the DC voltage connection (inductive, resistive, or both interfaces) and via the traction inverter (e.g., during recuperation). Energy can also be drawn from the energy storage device via the DC-DC converter to supply it to the traction drive, the DC voltage connection, or the aforementioned AC voltage connection.Stationary DC or AC power supply networks or island grids can draw energy from the vehicle's energy storage system via the DC or AC voltage connection. The same components of the DC-DC converter are used for these functions, resulting in component savings, particularly on the stationary side (but also on the vehicle side), compared to conventional circuits.

[0032] Furthermore, the power circuit may be provided with an AC connection, e.g., for a public power grid (especially the lowest distribution level of a low-voltage network of a public power grid), in particular the aforementioned AC connection. This connection is connected to the AC side of the DC-AC converter. The AC connection is designed in accordance with a standard, such as IEC 60309 or IEC 62196 (equivalent to DIN EN 62196), or a CENELEC standard for charging plugs or sockets. This AC connection (also called the AC terminal) is connected to the AC side of the DC-AC converter, in particular via a selector switch. An EMC filter and / or at least one (series) disconnect switch may also be provided between the AC connection and the DC-AC converter.

[0033] Another option is to equip the DC voltage connection, and if applicable, the AC voltage connection and / or the battery connection with a disconnect switch (as mentioned above). Instead of, or in combination with, the disconnect switch, an overload fuse can be used to protect the connections.

[0034] The DC and AC voltage connections can be integrated into a single electrical connection component. In this case, the DC and AC voltage connections can be configured as contacts of a common connector component. This connector component is designed according to a standard, such as IEC 60309 or IEC 62196 (equivalent to DIN EN 62196), or according to a CENELEC standard for charging plugs or sockets.

[0035] Furthermore, the traction inverter, the DC-DC converter, or both of these components can be configured to generate a controllable DC voltage at the interface point. This allows the output voltage of the DC-DC converter or the traction inverter to be adjusted so that it can be matched to the voltage level at the DC input, for example, if the voltage level at the DC input is determined by a connected power supply / island network and the output voltage at the DC input needs to be adjusted accordingly. The aforementioned control unit can be connected to the traction inverter or the DC-DC converter in such a way that the control unit can adjust the DC voltage at the first converter side of the DC-DC converter or at the DC side of the traction inverter.As already mentioned, the traction inverter is preferably designed to be bidirectional, in particular to be able to operate the connected traction drive as a motor and as a generator, or to be able to transmit power in the two opposite directions.

[0036] Furthermore, the power circuit or traction inverter can be equipped with a power measurement device. This device is designed to determine the energy (or power) flowing through the traction inverter in both directions. The power measurement device can be connected to the control unit, particularly to receive one or more signals indicating the measured energy or power. Alternatively or additionally, the DC-DC converter can also be equipped with such a power measurement device.The power metering device can be equipped with a communication interface that allows communication with a charging station connected via a DC or AC connection, for example, for cost accounting, driver and / or vehicle identification, or for transmitting the energy recorded by the power metering device (charged and / or discharged). Similarly, the power metering device can be used to record the energy transferred to the DC or AC connection. Furthermore, power (as a value) can be transmitted instead of or in combination with energy, for example, to control the energy flow, such as to limit it.

[0037] Having described how to use the connection point between a vehicle-side DC-DC converter and an inverter to directly connect a DC power supply (for connecting stationary equipment) to this connection point, the following section describes the complementary implementation, serving only to better understand the power circuit in question. In both implementations, the direct feed-in or tap-off capability directly from the DC-DC converter and simultaneously directly from the inverter (i.e., at the connection point) allows numerous components to be reused for different functions.

[0038] A stationary power supply system is therefore described. This system comprises a direct current line, an electrical energy source (preferably renewable, such as a photovoltaic system), an energy source-DC-DC converter that connects the energy source to the direct current line and is particularly bidirectional, an inverter connected to the direct current line, and a DC voltage connection.

[0039] The DC connection is designed for connecting an electrically powered vehicle. The DC connection can be a plug-in component and preferably conforms to a standard, such as IEC 60309 or IEC 62196 (equivalent to DIN EN 62196) or a CENELEC standard for charging plugs or sockets. The DC connection of the stationary power supply system is designed to complement the DC connection of the power circuit; in particular, both can be disconnected. A data interface can be provided, either integrated into the DC connection or designed as a radio interface, such as a short-range radio interface (WLAN, Bluetooth, etc.) or a Car-to-X communication interface (e.g., IEEE 802.11p). The data interface can be designed according to an IEEE 802.11 standard.The data interface is designed to transmit operating parameters such as maximum charging current, state of charge, charging duration, and other information. The DC connection of the stationary power supply system is directly connected to the DC line. The DC connection can also be directly connected to an electrical power source (such as a stationary battery or a fuel cell). This electrical power source can have a data interface configured like the one described above.

[0040] The inverter operates as a bidirectional inverter. Specifically, the inverter of the stationary power supply system functions as a bidirectional inverter. The inverter has an AC side, which is specifically designed to be connected to a power grid. The inverter has a DC side, which is connected to the DC line.

[0041] The DC line can have a high-voltage rated operating voltage, i.e., a rated operating voltage of at least 60 V and up to 220 V, 350 V, 400 V, 600 V, or 800 V. Alternatively, the DC line can have a rated operating voltage of 12 V, 14 V, 24 V, 36 V, 42 V, or 48 V. The components connected to the DC line are rated for a corresponding operating voltage.

[0042] The DC line forms a stationary DC intermediate circuit to which the inverter (for connecting to an AC power grid) is connected, and to which an off-grid (in particular, a photovoltaic system) can be connected. The off-grid is thus also connected to the general AC power grid via the inverter. Direct connection to a vehicle with an electric traction drive (i.e., with a high-voltage energy storage system) is provided via the DC input of the stationary power supply system. The DC-DC converter allows an off-grid with fluctuating voltage levels (or even just one power source within an off-grid, such as a photovoltaic system) to be connected to the DC line.

[0043] The stationary power supply system can have a grid connection that is directly connected to the inverter (its DC side). This grid connection can be directly connected to a public electrical grid or via a grid filter. Preferably, the public grid is not part of the stationary power supply system itself; rather, the stationary power supply system simply provides a grid connection that can be connected to the public grid.

[0044] The stationary power supply system may also have an AC connection, which is particularly complementary to the AC connection of the power circuit described above. Both AC connections can be disconnected from each other. The AC connection of the stationary power supply system is designed for connecting an electrically powered vehicle, in particular via the AC connection of the power circuit. The AC connection of the stationary power supply system is connected to the AC power grid, preferably via disconnect switches and / or fuses. The AC connection is particularly connected to the grid connection.

[0045] The stationary power supply system can also include a stationary electrical energy storage device. Furthermore, the stationary power supply system can include a storage DC-DC converter. This converter is specifically designed to be bidirectional. The storage DC-DC converter connects the stationary electrical energy storage device to the DC line.

[0046] Instead of the island grid or in combination with the island grid, fuel cells (or other DC voltage sources) can be provided, which are connected to the DC line via their own DCDC converter.

[0047] Complementing this, the power circuit can include another DC-DC converter and a connected DC voltage source, such as a second battery, with the additional DC-DC converter connecting the DC voltage source to the common-mode power supply. A range extender (with rectifier) ​​can also be used as the DC voltage source. Alternatively, a range extender can be provided whose generator is directly connected to the AC input or to the AC side of the inverter.

[0048] The DCDC converters of the stationary power supply system described here have two high-voltage DC sides.

[0049] The inverters and / or converters described here are designed for power outputs of at least 5 kW and preferably at least 10, 20, 30, 50, 70 or 100 kW. The power output is particularly less than 500 kW, preferably less than 200 kW or not more than 100 kW.

[0050] The inverter of the stationary power supply system, and in particular its AC side, is preferably multi-phase, especially for connection to a three-phase AC system. The AC connection of the stationary power supply system is also preferably multi-phase, especially for connection to a three-phase AC system. A line filter, preferably a multi-phase (e.g., three-phase) line filter, may be located between the inverter of the stationary power supply system and the grid connection. Brief description of the drawings The Fig. Figure 1 shows an exemplary power circuit to illustrate embodiments of the invention. The Fig. Figure 2 shows an exemplary stationary energy supply system to illustrate embodiments of the invention. The Fig. Figure 3 shows another exemplary power circuit, particularly to illustrate an automatic configuration. Detailed description of the drawing

[0051] In the Fig. Figure 1 shows a power circuit 10 comprising a DC voltage connection 20, an electric traction drive 30 (as a placeholder for the generally mentioned electric machine), an inverter 40, and a DC-DC converter 50. The DC-AC converter or inverter 40 (hereinafter referred to as the traction inverter due to the example chosen in the figure) has an AC voltage side 42, which can also be called the AC side, and a DC voltage side 44, which can be called the DC side. The DC-DC converter 50 has two high-voltage converter sides 52, 54, with a first converter side 52 of these high-voltage converter sides being connected to the DC voltage side 44 of the traction inverter 40 for power transmission.The connection between the first converter side 52 of the DC-DC converter 50 and the DC voltage side 44 of the traction inverter 40 has a junction point 60 to which the DC voltage terminal 20 is connected (via an optional DC disconnect switch 22). In other words, the DC voltage terminal 20 is connected to both the first converter side 52 of the DC-DC converter 50 and the DC voltage side 44 of the traction inverter 40 for power transmission. This connection, or junction point, can be considered an intermediate circuit between the traction inverter 40 and the DC-DC converter 50, to which the DC voltage terminal 20 is connected. Both sides of the DC-DC converter 50 operate in the high-voltage range with the operating voltages mentioned above, which are associated with the prefix "high voltage," although operating voltages outside the high-voltage range are also conceivable (as mentioned above).

[0052] The traction inverter (generally: the DC-AC converter) and the DC-DC converter are bidirectional. A detailed diagram 56 of the DC-DC converter shows its basic structure with a first smoothing capacitor C1, a semiconductor switch with two transistors, which are preferably implemented as n-MOSFETs, although implementations as SiC power semiconductors or IGBTs are also possible. Reference is also made to the substrate diodes of the transistors shown, as well as their forward biases, which point to the positive potential. Instead of n-MOSFETs, IGBTs (as shown) can also be used as semiconductor switches. The semiconductor switches are connected in series. An inductor is connected in series to the common junction resulting from this connection, with a second smoothing capacitor C2 connected to the side opposite (to the semiconductor switches). The first converter side 52 of the DC-DC converter 50 (orThe terminals of the first converter side are formed by the terminals of the first smoothing capacitor C1. The second converter side 54 of the DC-DC converter 50 (or the terminals of the second converter side) is formed by the terminals of the first smoothing capacitor C2. The smoothing capacitors are each connected in parallel. This results in a synchronous converter. The terminals, or converter sides, of the DC-DC converter 50 are designed for two voltage potentials (positive terminal / negative coil or positive terminal / ground).

[0053] A detailed illustration 46 of the traction inverter 40 (generally: the DC-AC converter) shows a B6C bridge with a smoothing capacitor C3 connected in parallel, which is located on the DC side 44 (or at the terminals of the DC side) of the traction inverter 40. Starting from the smoothing capacitor C3, controllable semiconductor switches are provided to the AC side in three separate phases in a bridge configuration (i.e., in a so-called B6C circuit). For each of the three phases, two series-connected semiconductor switches are provided, at the junction of which the individual phase conductors of the AC side originate. The AC side 42 (or its terminals) is thus three-phase. The traction inverter 40 is bidirectional. The semiconductor switches of the traction inverter 40 can be implemented as IGBTs, SiC power semiconductors or n-MOSFETs.In particular, the semiconductor switches can each be equipped with an antiparallel diode connecting the terminals to be switched. The diodes have a forward bias towards the positive terminal (of the DC side 44). When using SiC power semiconductors within the traction inverter 40 (generally: the DCAC converter), it can also be used to generate a current for inductive charging, the frequency of which can be in the range of 100 kHz or higher, due to the high (maximum) switching frequencies of the inverter 40.

[0054] The power circuit 10 can include a control device 65 that controls the DCDC converter and the traction inverter and, in particular, their semiconductor switches.

[0055] The traction drive 30 is further equipped with disconnect switches 34, which, like the disconnect switches 72 provided at an alternatively mounted position, can disconnect the electric machine from the AC connection 70. A selector switch 31 is connected downstream of the DC-AC converter 40 or its AC side. The common terminal of the selector switch 31, which can be selectively connected to one (or more) individual terminals of the selector switch 31, is connected to the DC-AC converter 40 or its AC side 42. One of the individual terminals, which can be connected to the common terminal of the selector switch in a controlled manner, is connected to the electric machine 30. Another of the individual terminals is connected to the AC connection 70, in particular via the disconnect switch 34 and / or the disconnect switch 72, and also preferably via the EMC filter 36.The selector switch, the relevant connections, the disconnect switch(es) and the EMC switch are designed for single or multi-phase operation.

[0056] On the side of the EMC filter 36 facing away from the traction drive 30, there is an AC voltage connection 70, which is connected to the EMC filter 36 (or indirectly to the traction drive 30) via the series disconnect switch 72. A single disconnect switch is connected in series to each phase. When the disconnect switches 70 are open, the capacitor bank 36 or the traction drive 30 is disconnected from the AC connection 70. When the disconnect switches 70 are closed, the capacitor bank or (indirectly) the traction drive 30 is connected to the AC connection 70.

[0057] The disconnect switch 34 is connected between capacitor bank 36 and the electric machine and forms an alternative to the disconnect switch 72, which is connected between capacitor bank 36 and the AC terminal 70. Therefore, both positions (34 and 72) for switches of the same function ("disconnect switches") are shown.

[0058] The disconnect switch 72, which can be assigned to the AC voltage connection 70, and the alternative disconnect switch 34 serve to interrupt the phases or the connection between the electric machine 30 and the AC voltage connection 70. The disconnect switch 34 and the disconnect switch 72 are located inside the vehicle, so that the power circuit can protect itself against external influences by actuating the disconnect switch.

[0059] The control unit 65 can detect operating parameters such as the current flowing through a component of the power circuit or the temperature of one of these components and activate the disconnect switch if a predefined limit is exceeded. The disconnect switch 34 and the disconnect switch 72 can be referred to as AC disconnect switches to better illustrate their function. The control unit 65 can be connected to the disconnect switches 34 and 72 in a controlling capacity.

[0060] The arrows shown indicate the control connection from the control unit 65 to the respective components and represent a control signal transmission. In particular, the controlled connection between the control unit 65 on the one hand and the disconnect switch 72, the disconnect switch 34, and the selector switch 31 on the other is shown.

[0061] The solid lines shown (without further markings) represent DC power transmission connections configured as two-wire systems. The solid lines shown, marked with a slash, represent AC power transmission connections, particularly three-phase connections. This also applies to the Fig. 2 to. The dotted line of the Fig. 1 indicates the membership of components in the power circuit.

[0062] An optional traction battery 80 belonging to the power circuit 10 is connected to it via an electrical energy storage connection 82 of the power circuit 10. The energy storage connection 82 is connected to the second converter side 54 (at high-voltage voltage level) of the DC-DC converter 50. A vehicle-side mains socket 74 can be connected downstream of the disconnect switch 72 and, more generally, to the DC-AC converter or inverter 40 (or its AC voltage side 42). The DC-AC converter 40 can be used as an inverter to generate an AC voltage typical for public power grids (e.g., 110 or 230 V at 50 or 60 Hz). A selection switching device can be provided between the disconnect switch 72 on the one hand and the external connection (AC voltage connection 70) and / or the internal connection (vehicle-side mains socket 74).Such a selection switching device can be implemented by the selection switch 31, but can also be provided by a further selection switch (not shown) between the EMC filter 36 and the AC terminal 70. In this case, the further selection switch (not shown) can be located at the position of the disconnect switch 72, or be implemented together with it. Such a selection switching device is preferably connected to the control unit 65. The further selection switch can generally be provided between the AC voltage side 42 of the traction inverter 40 on the one hand and the terminals 70 or 74 on the other.

[0063] Fuses and / or mains filters may be provided between the traction inverter 40 and the terminals 70 or 74, for example between the selection circuit (see selection device or selection switch 31 above) and the traction inverter 40 or between the selection circuit and the terminals (i.e. the mains socket or the AC terminal 70).

[0064] Furthermore, a vehicle-side coil of an inductive coupling device, or a connection for one, may be provided. The coil or the associated connection may be directly or indirectly connected downstream of the AC voltage side 42. The coil or its connection may also be connected to the DC terminal 82 or to the interconnection point 60 via an additional (preferably bidirectional) inverter used for coil current generation.

[0065] The following possible power flows result from the topology: - from the DC voltage connection 20 via the DCDC converter 50 to the energy storage connection 82 (charging the vehicle's energy storage system, DC voltage) - from the energy storage connection 82 via the DCDC converter 50 to the DC voltage connection 20 (supporting an external power supply network from the vehicle's energy storage system) - from the energy storage connection 82 via the DCDC converter 50 and the traction inverter 40 to the mains socket 74 or to a coil connected downstream of the traction inverter 40 for inductive energy transfer (or to its connection) - from the DC voltage terminal 20 via the DC-DC converter 50 and the inverter 40 to the AC voltage terminal 70 (or to the mains socket 74 or to a coil connected downstream of the traction inverter 40). In this application, the

[0066] Power switching as a "mobile inverter", for example to feed direct current from a photovoltaic system into a public grid (or a local alternating current grid).

[0067] The control unit 65 is configured to control the components it controls according to at least one and preferably all of these power flows.

[0068] Further applications are possible, particularly those mentioned later in this description, such as parallel AC and DC charging. The external energy storage device can also be the electrical energy storage device of another vehicle, so that the latter case involves the transfer of energy from one vehicle to another.

[0069] Preferably, the power circuit 10 is configured to detect operating parameters such as the applied voltage type and / or voltage level in order to configure at least one component of the power circuit according to one of the applications or power flows mentioned herein. This preferably occurs automatically, i.e., without user input. The power circuit can be configured to display the possible configurations (or applications or power flows) on a user interface when multiple applications or power flows are possible and to detect the option selected by the user.

[0070] The power circuit is specifically designed to detect the aforementioned operating parameters at the terminals, particularly at the external terminals such as the DC terminal 20, the AC terminal 70, the energy storage terminal 82, and / or a terminal for connecting a coil for inductive energy transfer. For example, it can determine whether voltage is present at the respective terminals. Alternatively, or in combination with this, the power circuit 10 can be designed to detect the operating parameters within the power circuit 10, in particular the voltage at the interconnection point 60, on one side (side 42 and / or 44) of the traction inverter 40, or at the EMC filter 36. For this purpose, the power circuit 10 can include a voltage detection unit. This unit can be coupled to or be part of the control unit 65.

[0071] As already mentioned, the power circuit 10 can have a selection circuit, in particular a selection circuit between several connections that are connected to the DC voltage connection 20 via the selection circuit. These connections are, in particular, the resistive interface and the inductive interface. Alternatively or in combination with this, a selection circuit between several connections and the AC power connection 70 can be provided. The latter connections are, in particular, a connection to an AC power supply network 140, the vehicle-side mains socket 74, and / or a connection to a coil for inductive power transfer. The control unit 65 is configured to set this selection circuit or selection circuits according to one of the power flows, applications, or configurations. The control unit is, in particular, configured to control the disconnect switch 34 connected to the traction drive 30.

[0072] The control unit 65 is specifically designed to adjust the frequency, voltage, and / or current of components of the power circuit 10 according to the application or configuration to be set, or according to the energy flow to be set. For example, if the vehicle's mains socket 74 is connected, the frequency and voltage of the traction inverter 40 are set according to the frequency (e.g., 50 or 60 Hz) and voltage of a public power grid 140. If a coil intended for inductive power transfer is connected to the traction inverter 30, a frequency is selected that corresponds to the desired alternating field of the coil, which may be in the range of several kilohertz, particularly in a range above 50 or 70 kHz.

[0073] Furthermore, the control unit 65 is configured to adjust the voltage at the connection point 60 and / or at the energy storage connection 82. In other words, the control unit 60 is configured, in particular, to adjust the voltage at at least one side of the DCAC converter 40 and / or the DCDC converter 50, or the current flowing there.

[0074] The combination of the desired state of the selection circuit(s) and the desired operating parameters (such as voltage, frequency, or current) can be referred to as the target operating mode. This corresponds to the application or energy flow to be set and can also be equated with the configuration.

[0075] One embodiment provides that the power circuit 10 is equipped with the selection circuit. The selection circuit includes a voltage detection unit, in particular the voltage detection unit described above. The voltage detection unit is connected to at least two of the following components: the traction drive 30, the AC voltage connection 70, the DC voltage connection 20, the energy storage connection 82, and the coil for inductive energy transfer. The voltage detection unit is further configured to detect whether a voltage is applied to the respective component in order to set the selection circuit, a frequency of the traction inverter 40, and / or a voltage of the traction inverter 40 according to a possible operating mode or a predetermined target operating mode.

[0076] Furthermore, in the Fig. One component is shown to illustrate application scenarios. A stationary DC power supply network (connectable to the general power grid or as an off-grid solution) comprises a photovoltaic system 100 with a connected DC-DC converter 102 and a stationary energy storage system 110 with a connected DC-DC converter 112. The stationary DC power supply network includes a stationary DC line (DC network) to which the photovoltaic system 100 and the stationary energy storage system 110 are connected via their respective converters 102 and 112. Additional loads or energy sources can be connected, such as a fuel cell 120, which is connected to the DC line via its own converter 122.The photovoltaic system 100, the stationary energy storage system 110 and / or the fuel cell 120 can be connected to the DC voltage connection 20 of the power circuit 10, in particular for bidirectional power exchange or even just for transferring power to the power circuit 10.

[0077] Furthermore, the DC power supply network can be connected to a general AC power supply network via a (preferably bidirectional) stationary DC-AC converter 130 (and a downstream network filter 132). The connection to the AC power supply network 140 can be protected by overload fuses 142. The components 100, 110, and / or 120 of the DC power supply network can be connected to the AC power supply network 140 via the DC-AC converter 130, for example, to feed energy into the AC power supply network 140 or to draw energy from the AC power supply network 140 (this applies in particular to the stationary energy storage device 110 or the fuel cell 120, which then operates as an electrolyzer). The vehicle-side AC voltage connection 70 can be connected to the stationary DCAC converter (via the mains filter 132, which is optional) orIt can be connected to the general AC power supply network 140 (via the overload protection devices 142). This enables energy transfer between the stationary DC network (island network) or the general AC power supply network 140 on the one hand and the vehicle-side power circuit 10 on the other. This energy transfer can be bidirectional or unidirectional in either direction.

[0078] In particular, power can be simultaneously transferred to the power circuit via the AC terminal 70 and the DC terminal 20, especially for charging the electrical energy storage device 80. This application can also be described as parallel AC and DC charging. This allows for significantly shorter charging times. Furthermore, several energy sources can be used simultaneously to charge the energy storage device, such as a public power grid and a local power plant, such as a photovoltaic system. This application also illustrates the potential for savings offered by the invention, since the traction inverter 40, which is (also) used to generate the rotating magnetic field in the drive 30, is used for a different function, namely AC / DC conversion and, in particular, for controlling the energy flow from the AC terminal 70 towards the energy storage device 80.The savings in power components through this multiple use are considerable due to the high cost of power semiconductors.

[0079] Furthermore, the power circuit 10 can draw power from the general stationary AC grid 140 via the AC connection 70 and supply it to the stationary DC grid (in particular to the fuel cell 120 and / or the stationary energy storage system 110) via the traction inverter 40 and the DC-DC converter 50 at the DC connection 20. This allows the DC-AC converter 130 to be relieved of some of its load when drawing power from the AC grid 140. In particular, it can be dimensioned with a lower power rating (compared to operating without the power circuit), since the vehicle or the power circuit 10 is usually largely available when the fuel cell 120 or the stationary energy storage system 110 is being charged (with off-peak electricity or at a favorable tariff).

[0080] The Fig. Figure 2 shows a stationary power supply system 200 with a DC line 260, at least one electrical power source 202, 204, 206, and at least one power source-to-DC converter 203, 205, 207, which connects the respective power source 202, 204, 206 to the DC line 260 (DC supply network, island grid). Each electrical power source 202, 204, 206 is connected to the DC line 260 via one of the power source-to-DC converters 203, 205, 207. (According to an embodiment not shown, the electrical power sources can be connected directly to the DC line without converters.) Energy source 202 can be a photovoltaic system, energy source 204 can be a fuel cell, and energy source 206 can be a stationary electrical energy storage system.The converters 203, 205, and 207 can be unidirectional (energy flow from the energy source to the DC line 260), as in the case of converter 203, or bidirectional, as in the case of converters 205 and 207. Bidirectional energy source-to-DC converters are used when the energy source that the converter connects to the DC line 260 is also designed to store energy, as in the case of the electrical energy storage device 206, which is designed as a stationary battery, or in the case of the fuel cell 204. The energy source-to-DC converters serve to connect an energy source to the DC line 260 and therefore bear the prefix "energy source".

[0081] Furthermore, the stationary power supply system 200 includes an inverter 230, whose DC side 232 is connected to the DC line 260, as well as a DC voltage connection 220 and an AC voltage connection 270. The AC voltage connection 270 is connected to an AC side 234 of the inverter 230. The inverter 230 is, in particular, a bidirectional DC-AC converter. The AC side 234 and the AC voltage connection 270 are multi-phase, specifically three-phase. The AC voltage connection 270 is used to connect a vehicle.

[0082] The DC terminal 220 is designed for connecting an electrically powered vehicle 290. In this respect, terminal 270 and terminal 220 have identical characteristics and may be combined in one terminal, for example as a socket according to a CCS charging connector system as per IEC 62196. The DC terminal 220 is directly connected to the vehicle's DC power bus (possibly via overload protection, filters, or series disconnect switches).

[0083] The AC terminal 270 is also designed for connecting an electrically powered vehicle 290 and is connected to the DC line 260 via the inverter 230. Alternatively or additionally to the DC terminal 220, a vehicle can also be connected via the AC terminal 270. A traction inverter 340 can be connected downstream of the electric motor on the vehicle side. In this way, the AC terminal is connected via the electric motor 330 and the (bidirectional) traction inverter 340 to a connection point to which the (stationary) DC terminal 220 and a vehicle-side DC-DC converter 250 are also connected. The vehicle-side DC-DC converter 250 connects the (stationary) DC terminal 220 to a vehicle-side energy storage device 280.

[0084] In an alternative embodiment, the DC-DC converter 250 is stationary (and thus part of the power supply system) and is connected upstream of terminal 220. An EMC filter can be provided on the vehicle side.

[0085] Alternatively or additionally, the AC voltage connection 270 is connected to a general AC supply network 240 (possibly via disconnect switches, filters and / or overload protection devices), where 242 denotes an electrical supply network building connection for a general AC supply network.

[0086] The supply network connection 242 can be connected to an electrical supply network, either directly or via a network filter 236. When using a network filter 236, the alternative AC voltage connection 242', which leads (directly) to the AC supply network 240 via the network filter, is connected to the AC connection 270. The network filter 236 is optional; the connections 242 and 242' are interchangeable.

[0087] The stationary power supply system can further comprise a stationary electrical energy storage device and a preferably bidirectional storage DC-DC converter that connects the stationary electrical energy storage device to the DC power bus.

[0088] The components with the following reference symbols are equivalent and can have the same properties: 100, 110, 120 ↔ 202, 204, 206 102,112,122↔203,205,207 20↔220 30↔330 40↔340 50↔250 70↔270 80↔280

[0089] The stationary power supply system is designed to complement the power circuit and is configured for connection with the power circuit.

[0090] The components with the following reference symbols correspond to each other in a complementary sense and can have the same properties (except for their vehicle-side or stationary arrangement): 60↔260 40↔230

[0091] In particular, the stationary energy supply system supports the following applications: - Energy transfer from energy source 202 to the supply network 240 (feed-in, feed-in); - Energy transfer from the supply network 240 to a (rechargeable) energy source 204, 206 (charging, stationary); - Energy transfer from a vehicle or its energy storage 280 via the DC connection 220 to a (rechargeable) stationary energy source 204, 206 (vehicle-side support stationary grid, energy transfer via DCDC converter 250); - Energy transfer from a vehicle via the DC connection 220 and the inverter 230 into the supply network 240 (vehicle-side feed-in to the supply network); - Energy transfer from the supply network 240 to the stationary energy source 204, 206 via the AC connection 270, the vehicle-side DCAC converter 340 and the DC connection 220. (vehicle-side feed-in to stationary energy storage / energy sources)

[0092] The latter energy transfer can be carried out simultaneously with an energy transfer from the supply network via the inverter 230 to the direct current line or to the relevant energy sources 204, 206.

[0093] Since energy sources 204 and 206 can also absorb and store energy, these components can also be referred to as electrical energy storage devices. These energy storage devices are generally electrostatic (capacitor) or electrochemical (capacitor, fuel cell, accumulator) energy storage devices, or a combination thereof.

[0094] The Fig. Figure 3 shows an exemplary power circuit 410 to illustrate the aspect of automatic or semi-automatic configuration. The power circuit 410 is equipped with a DC-AC converter 440 and a DC-DC converter 450 (preferably both bidirectional). A DC side of the DC-AC converter 440 is connected to the DC-DC converter 450, with a switching point 460 provided at this connection, to which a DC terminal 420 is connected (via a selector circuit 492). An electric traction drive 430 (i.e., an electric machine) is connected downstream of the AC side of the DC-AC converter 440. An (optional) disconnect switch 434 is connected downstream of the traction drive 430.Instead of or in combination with the disconnect switch 434, a separate mains filter 441 (with its own filter inductances) can be provided, which is connected downstream of the DCAC converter 440 and connects it to the selector switch 490 or to terminals 470, 474, 476 (as explained below).

[0095] The selector switch 490 is connected between the DC-AC converter 440 and terminals 470, 474, and 476. These terminals are used for connecting to AC loads or AC sources. Terminal 470 corresponds to the AC connection, which is provided for connection to a stationary AC power grid. Terminal 474 is specifically designed as a vehicle-side power outlet. Terminal 476 is a connection for a coil 428' for inductive power transfer. In the illustrated embodiment, the coil 428' is not part of the power circuit 410 and is therefore shown with dashed lines (as an option). In other embodiments, the coil 428' can be part of the power circuit 410.

[0096] The selector switch 490 is controlled by a control unit 465. A voltage detection unit 466 detects the voltages or voltage potentials at different points in the power circuit 410. In the Fig. Figure 3 shows the voltage detection symbolically with dashed arrows. Specifically, the voltages at terminals 474, 470, and 476 (for alternating current) and at terminals 426 and 420 (for direct current) are detected. Furthermore, the voltage at the energy storage terminal 482 can also be detected by the voltage detection unit 466. The voltage detection unit 466 detects, in particular, whether or not voltage is present at the terminals, or detects a voltage value, or detects whether a voltage is present that exceeds a predefined threshold. The voltage detection unit 466 is therefore able to detect whether the respective terminal is occupied or not. For example, it can detect that a voltage is present at terminals 420 and 470.The control unit can then deduce that both terminals can be used (simultaneously) to transfer electrical energy to the power circuit, for example, to charge an energy storage device (connectable to terminal 482). If voltage is present at only one of terminals 420 or 470, only that terminal is used to transfer energy to the power circuit 410. In addition to voltage, the voltage detection unit can determine, for example, by measuring resistance, whether an inactive element (generally a load) is connected to one of the terminals or whether the terminal is free. This allows it to detect, for instance, if terminal 476 (or 426) is connected to a coil (directly or indirectly), in order to apply a voltage signal to the terminal to excite the coil, if necessary.Since a resistance measurement can be performed, for example, by measuring a voltage when a current is applied, or by measuring a voltage across a shunt resistor when a voltage is applied to determine the current, the voltage detection unit can also be referred to as a voltage detection unit when functioning as a resistance measurement unit.

[0097] The selector switches 490 and 492 are controlled according to the arrows emanating from the control unit 465. These arrows symbolically represent the path of the control signals. In addition to the selector switches, the control unit 465 can also control converting or switching components of the power circuit 410, such as the DC-DC converter 450, the DC-AC converter 440, the disconnect switch 434, and / or the drive 430.

[0098] The control unit 465 can automatically or semi-automatically control the components described above according to a predefined program or assignment. The program or assignment links states (voltage / no voltage or infinite / non-infinite resistance) determined by the voltage sensing unit with target switching states of the selector switches 490 and 492, target frequencies of the DCAC converter 440, and / or target voltages on the AC or DC side of the DCAC converter or at one of the terminals. For example, if a load is plugged into terminal 474 for a mains socket, which can be detected via the finite resistance detectable there, then the DCAC converter 440 can be set to generate an AC voltage of 230 V at 50 Hz on the output side.In this configuration, the control unit, together with the voltage detection unit 466, can form a control system that regulates the voltage at the relevant terminal (here terminal 474) to a specific setpoint. Furthermore, the control unit 465 activates the selection circuit 490 to connect the DCAC converter 440 to terminal 474, whereby the disconnect switch 434 can be controlled to the "open" state.

[0099] Automatic assignment or programming refers to control by the control unit solely based on the detection by the voltage detection unit 466, without considering user input. The control unit 465 can display the detected states and / or the target states (or the associated applications or energy flows) on a user interface 467, in particular as an image on an electronic display. In semi-automatic assignment or programming, the detected states and / or the possible applications or energy flows are displayed. In this case, the user interface 467 detects which of the possibilities is selected, or a confirmation signal is detected. Based on the signal detected by the user interface, the control unit 465 controls the relevant components.In this case, the user interface is preferably a touch-sensitive screen or a display with buttons or other input devices to capture user input.

[0100] A coil 428 for inductive power transfer can be connected to terminal 426 of the selection unit 492, with a preferably bidirectional inverter 427 connected between the coil 428 and the terminal. Since the selection unit 492, or the DC side of the inverter 440 connected to it, is designed for DC voltage, but the coil 428 itself is operated with or generates AC voltage, the inverter 427 is necessary. In contrast, the coil 428' can be connected directly to the selection unit 490, since the selection unit (or the AC side of the DC-AC converter 440 connected to it) is also designed for AC voltage.

[0101] The selection units 490, 492 can be designed as electromechanical or, preferably, as electronic switching units. In particular, the selection units 490, 492 can have several switches that connect the junction point 460 or the AC side of the DC-AC converter 440 to the respective terminals 420, 426 or 470, 474, 476, respectively, in a freely selectable manner. Several terminals can be switched on simultaneously from one of the selection units, or the selection units can be designed as changeover switches in which only one terminal is switched on at a time.

[0102] The components of the Fig. 3 and the Fig. 1 with the following reference symbols correspond to each other, where corresponding components may have the same properties: 30↔430 40↔440 50↔450 60↔460 65↔465

[0103] The AC connection 70 of the Fig. 1 is the only connection that leads (indirectly) to the traction drive 30. Since in the Fig. Since the selector switch 490 is located on the external side of the selector switch 490, the connection 470, intended for connection to a power supply network, is located on the external side of the selector switch 490. Except for the intermediate connection of the selector switch, the AC voltage connection 70 and the connection 470 are therefore identical. The same applies to the DC current connection 20 and the (selectable) connection 420.

Claims

[1] Power circuit (10) for power supply in an electrically powered vehicle, wherein the power circuit (10) comprises: - a DC voltage connection (20); - at least one DC-AC converter (40) having an AC side (42); and - at least one DC-DC converter (50) with two converter sides (52, 54), wherein the first converter side (52) is connected via a junction point (60) to a DC voltage side (44) of the DC-AC converter (40) and the DC voltage connection (20) is likewise connected to this junction point (60), wherein the power circuit (10) further comprises an energy storage connection (82), wherein the second converter side (54) of the DC-DC converter (50) is connected to the energy storage connection (82), which is provided for connecting a vehicle-side energy storage device (80), wherein the power circuit (10) is equipped with a changeover switch that controllably connects the DC voltage connection (20) either to the junction point (60) or to the energy storage connection (82) and / or to a selection circuit (31) that selectably connects the DC-AC converter (40) to an electric machine (30) or a connection thereto, with an internal AC power connection (74),connects to an external AC voltage connection (70) and / or to a coil for inductive power transfer. [2] Power circuit (10) according to claim 1, wherein the DCAC converter (40) is an inverter of a charging device, or the power circuit (10) comprises an electric machine (30) or a connection thereto, wherein the AC side (42) of the DCAC converter (40) is connected to the electric machine (30) or to the connection thereto and forms an inverter for the electric machine (30). [3] Power circuit (10) according to claim 1 or 2, wherein the DCDC converter (50) is configured for bidirectional power transfer between the two converter sides (52, 54). [4] Power circuit (10) according to one of the preceding claims, which further comprises an AC voltage connection (70), wherein the power circuit (10) comprises an electric machine (30) or a connection thereto and the electric machine (30) has windings that can be separated from one another, wherein the DCAC converter (40) is connected in series to the AC voltage connection (70) via at least one winding. [5] Power circuit (10) according to one of the preceding claims, wherein the DC voltage connection (20) and / or the energy storage connection (82) comprise a disconnect switch (22, 72) and / or an overload protection device (142). [6] Power circuit (10) according to one of the preceding claims, which is equipped with the selection circuit (31), wherein the selection circuit (31) has a voltage detection unit which is connected to at least two of the following components: the electric machine (30) or the connection thereto, the AC voltage connection (70), the DC voltage connection (20), the energy storage connection (82) and the coil for inductive energy transfer, wherein the voltage detection unit is further configured to detect whether a voltage is applied to the component in question in order to set the selection circuit (31), a frequency of the DCAC converter (40) and / or a voltage of the DCAC converter (40) according to a possible operating mode or a predetermined target operating mode. [7] Power circuit (10) according to one of the preceding claims, wherein the DC voltage connection (20) and the AC voltage connection (70) are designed as contacts of a common plug-in component. [8] Power circuit (10) according to one of the preceding claims, wherein the DCAC converter (40) and / or the DCDC converter (50) are configured to generate a controllably variable DC voltage at the connection point (60). [9] Power circuit (10) according to one of the preceding claims, wherein the DCAC converter (40) is equipped with a power sensing device which is configured to determine the energy flowing through the DCAC converter (40) for both flow directions.

Images