Converter device

Abstract

The invention relates to a converter device, in particular for supplying a low-voltage DC secondary side in a motor vehicle, comprising: - a high-voltage DC primary side and a low-voltage DC secondary side; wherein - the high-voltage DC primary side and the low-voltage DC secondary side are galvanically separated by a transformer; - the high-voltage DC primary side has at least one channel; - the low-voltage DC secondary side has at least two channels, each of which feeds a DC network on the channel output side; - each channel has at least one path; - the paths of the channels of the low-voltage DC secondary side are electrically connected to a secondary winding of the transformer on the path input side in each case; - each path has at least one AC / DC converter; - the high-voltage DC primary side has a channel with a bidirectional n-phase AC / DC converter, where n ≥ 3; - the low-voltage DC secondary side has at least one channel with a bidirectional AC / DC converter; and - an energy store is electrically connected to one of the channels of the low-voltage DC secondary side having a bidirectional AC / DC converter on the channel output side. -

Description

[0001] Converter Device The invention relates to a converter device, in particular for supplying a low-voltage DC secondary side in a motor vehicle according to claim 1, and to a method for operating a converter device, in particular for ensuring the reliable supply of a low-voltage power supply network in a motor vehicle in the event of a fault, according to claim 19. In motor vehicles, especially in electric vehicles and / or in vehicles that drive autonomously or at least partially autonomously, the requirements for the supply of safety-relevant consumers are constantly increasing under relatively high cost pressure. In particular, the structure and quality of the safety functionality are defined by the content of the ISO 26262 standard and various other automotive standards.In electric vehicles, a main battery, preferably a high-voltage battery with a terminal voltage of 200 V or greater, is typically installed. To supply safety-critical components, it is advantageous, particularly during normal operation, to use this main battery to power the low-voltage DC secondary side. A converter circuit for transferring electrical energy, especially in a motor vehicle, is known, for example, from patent application WO 201302 98 27 A2. This patent application discloses a converter circuit that allows energy transfer between a high-voltage battery and a low-voltage battery. The energy transfer between the low-voltage and high-voltage batteries is carried out by inverters with two strings.A problem with such a converter circuit is that if a semiconductor fails, and thus a string fails, power transfer between, for example, the high-voltage battery and the low-voltage battery is no longer possible. The present invention addresses this problem. This problem is solved by a converter device with the features of claim 1 and by a method for operating the converter device in the event of a failure, according to claim 19. Advantageous embodiments and further developments of the invention are specified in the dependent claims. According to the invention, a converter device, in particular for supplying a low-voltage DC secondary side in a motor vehicle, comprises a high-voltage DC primary side and a low-voltage DC secondary side. The high-voltage DC primary side and the low-voltage DC secondary side are galvanically isolated by a transformer.The high-voltage DC primary side has at least one channel, and the low-voltage DC secondary side has at least two channels, each feeding a DC network at its output. Each channel has at least one path, and the paths of the channels on the low-voltage DC secondary side are each electrically connected at their input to a secondary winding of the transformer. Each path has at least one AC / DC converter. The high-voltage DC primary side has one channel with a bidirectional n-phase AC / DC converter, where n ≥ 3. The low-voltage DC secondary side has at least one channel with a bidirectional AC / DC converter, and an energy storage device is electrically connected at its output to at least one of the channels of the low-voltage DC secondary side with a bidirectional AC / DC converter. The invention is based on the idea of ​​creating redundancies in power transmission, particularly to comply with specified safety standards.The primary purpose of this is to ensure the vehicle's functionality for a certain period of time in the event of a malfunction, enabling it to reach the nearest repair shop or, in the case of a particularly serious fault, at least to safely remove the vehicle from the immediate danger zone, namely the roadway. The aforementioned ISO 26262 standard defines so-called Automotive Safety Integrity Levels (ASILs). This standard defines the functional safety of electrical and / or electronic systems in vehicles. The ASIL classification assesses the risk of malfunctions in such systems and determines which safety measures are required. The ASIL classification comprises four levels, namely ASIL A to ASIL D, with ASIL A representing the lowest safety requirement and ASIL D the highest.Advantageously, at least one channel of the low-voltage DC secondary side has at least two paths, wherein the paths of the channel are electrically connected to each other at the path output side and form the output of the channel. A DC network is electrically connected to the output of the channel. If an AC / DC converter located within one path of the two-path channel fails, power transmission takes place via the other path of the same channel. Preferably, each channel of the low-voltage DC secondary side has at least two paths, wherein the paths of the channel are electrically connected to each other at the path output side. Consequently, a redundant power path is formed in each channel. If one path fails, for example due to the failure of an AC / DC converter, power transmission takes place via the other path. Furthermore, it is possible to transfer power from one DC network to another.According to an advantageous embodiment of the invention, one AC / DC converter of a channel on the low-voltage DC secondary side is configured as a bidirectional AC / DC converter, and another AC / DC converter of the same channel is configured as a unidirectional AC / DC converter. Bidirectional AC / DC converters preferably employ actively switchable semiconductors, while unidirectional AC / DC converters employ passive semiconductors. Unidirectional AC / DC converters have the advantage over bidirectional AC / DC converters of generally being less expensive. According to the invention, an energy storage device is electrically connected to at least one of the channels on the low-voltage DC secondary side at the channel output. When the primary side is disconnected from the secondary side, the power transmission for the DC network that is not electrically connected to the energy storage device must also be able to be supplied via this energy storage device.For this to work, at least one path of the channel connected to the energy storage device must allow bidirectional power flow. Power transfer from the energy storage device occurs via the bidirectional path, the transformer, and then the preferably unidirectional AC / DC converter. Advantageously, the power flow, or rather the topology used, from one DC network to another on the low-voltage DC secondary side is comparable to that of a push-pull converter, preferably a full-bridge push-pull converter. In a full-bridge push-pull converter, a transformer separates a full bridge of actively switchable semiconductors from a full bridge of passive semiconductors. The push-pull converter can also be three-phase.In another advantageous embodiment of the invention, the power flow from one DC network to another, or its topology, is comparable to a single-ended push-pull converter. In a preferred embodiment of the invention, all AC / DC converters of a channel on the low-voltage DC secondary side are configured as bidirectional AC / DC converters. This allows for any desired power flow between the DC networks on the low-voltage DC secondary side. For example, all DC networks can be electrically connected to an energy storage device and supply the respective other DC networks with energy via this energy storage device.According to a particularly advantageous embodiment of the invention, an AC / DC converter of one channel of the low-voltage DC secondary side is configured as a three-phase AC / DC converter, and an AC / DC converter, preferably the unidirectional AC / DC converter, of the same channel is configured as a two-phase AC / DC converter. Preferably, at least on the low-voltage DC secondary side, two-level AC / DC converters are used. In two-level AC / DC converters, each phase preferably comprises two semiconductors connected in series. The number of levels indicates the number of voltage levels at the output of a phase. In two-level AC / DC converters, the full DC link voltage is always present at the output. The individual phases of an AC / DC converter are connected in parallel. AC / DC converters with only two phases have the advantage that, in a two-level topology, they require only four semiconductors and are therefore inexpensive to purchase.Typical two-phase AC / DC converters are full bridges, also known as H-bridges. Three-phase AC / DC converters have three phases. Three-phase AC / DC converters have the advantage of being able to transmit higher power. Furthermore, if one phase of the three-phase AC / DC converter fails, reduced power transmission can still occur. Additionally, three-phase AC / DC converters exhibit better harmonic distortion than, for example, two-phase AC / DC converters. Advantageously, all AC / DC converters of a channel on the low-voltage DC secondary side are designed as three-phase AC / DC converters. The three-phase AC / DC converters are preferably configured as a B6 bridge, also known as a three-phase bridge circuit. Preferably, three channels are provided on the low-voltage DC secondary side, with each channel preferably being electrically connected to a DC network at its channel output.On the low-voltage DC secondary side, more than three channels, for example four, five, or six channels, can be configured. For example, one or more channels can be electrically connected to one or more energy storage devices. According to an advantageous embodiment of the invention, at least one channel of the low-voltage DC secondary side has three paths. A channel with three paths is advantageous because it increases redundancy in power transmission. A channel can also have more than three paths. For example, a channel can have four, five, or six paths, with the paths being electrically connected to each other on the output side. A higher number of paths increases redundancy in power transmission. It is also possible for more than one channel to have three or more paths. Advantageously, all channels have three or more paths.In a particularly preferred embodiment of the invention, the high-voltage DC primary side has at least two channels, each channel comprising one path. The high-voltage DC primary side can also have more than two channels; for example, it can have three, four, or five channels. At least one channel of the high-voltage DC primary side can have more than one path. For example, one path of the high-voltage DC primary side can have two, three, four, or five paths, with at least one of the paths comprising a three-phase AC / DC converter. In a particularly advantageous further development of the invention, a high-voltage battery is electrically connected to the input side of the high-voltage DC primary side. The high-voltage battery preferably has a terminal voltage greater than or equal to 200 V, more preferably greater than or equal to 800 V, and most preferably greater than or equal to 1000 V.The capacity of the high-voltage battery is preferably between 20 and 150 kWh, particularly preferably between 60 kWh and 100 kWh. A lithium-ion, lithium iron phosphate, or solid-state battery is preferably used as the high-voltage battery. An additional converter device can be connected between the high-voltage DC primary side and the high-voltage battery. For example, a buck converter, boost converter, or dual active bridge can be connected between the high-voltage DC primary side and the high-voltage battery. The high-voltage battery can be charged via a connection not belonging to the converter device according to the invention. In a purely electric vehicle, the high-voltage battery is preferably charged via an external charging station. The high-voltage battery can also be charged via an internal combustion engine, for example, in a vehicle that can be operated both electrically and with an internal combustion engine.Advantageously, the high-voltage battery has a center tap and a normal tap, with the center tap feeding one channel of the high-voltage DC primary side and the normal tap of the high-voltage battery feeding another channel of the high-voltage DC primary side. A battery with a terminal voltage of 800 V has a center tap at 400 V. This results in two battery stacks connected in parallel. If a fault occurs in one of the battery stacks, for example in the form of a short circuit, the battery management system (BMS) disconnects the faulty battery stack from the overall system. The power supply then takes place only via the fault-free battery stack. According to an advantageous embodiment of the invention, a bypass diode is connected in parallel to the individual battery stacks, whose battery cells are connected in series. In the event of a fault, the bypass diode allows the current to bypass the failed battery stack.Each battery cell in a battery stack can also have a bypass diode that, in the event of a fault within the battery cell, diverts the current around the faulty cell. The high-voltage battery, when charged, can be electrically or electromagnetically coupled via another connection to a further converter device, for example, a three-phase dual-active bridge. The converter device that primarily charges the high-voltage battery is preferably electrically connected to an AC network, particularly preferably to a low-voltage AC network. Preferably, the primary and secondary windings of the transformer are wound on a single magnetic core. The advantage of a single magnetic core is that the transformer can be built very compactly and lightweight. This is particularly important in the automotive sector.The primary and secondary windings of the transformer can also be wound on different magnetic cores. Preferably, the transformer is designed as a toroidal transformer, also known as a ring-shaped transformer. Toroidal transformers typically have a ring-shaped core made of a ferromagnetic material. The primary and secondary windings are wound evenly around this core. The windings can be arranged one above the other or side by side. Several secondary or primary windings can also be wound on the core to generate different input and output voltages. Insulating layers are inserted between the windings to ensure galvanic isolation at all times. In a further preferred embodiment of the invention, the transformer is designed as a double-E type transformer.The magnetic core of the double-E-type transformer is formed from two identical E-shaped core halves, creating three columns. Preferably, the primary and secondary windings are wound around the central column of the E-core. Consequently, the magnetic flux is greatest within the central column. Core-type transformers, shell-type transformers, three-legged transformers, or five-legged transformers can also be used. This list is not exhaustive. In a further advantageous embodiment of the invention, the transformer comprises a plurality of thin insulated sheets or laminations, between which an insulating material or foil is arranged. This minimizes, in particular, eddy current and hysteresis losses.Preferably, a capacitor and an inductor are connected in series with the primary and secondary windings of the transformer on both the primary and secondary sides, forming a CLLC topology. The CLLC topology consists of two capacitors and two inductors, with the inductors being formed separately or exclusively by the leakage inductance of the transformer's primary and secondary windings. An advantage of the CLLC topology is that the converter device can be operated relatively easily in zero-voltage switching and / or zero-current switching modes. Zero-voltage switching means that switching occurs at the zero-voltage crossing. Zero-current switching means that switching occurs at the zero-current crossing.By carefully selecting the capacitance and inductance values ​​of the capacitor and / or inductor connected in series with the primary and / or secondary winding, zero voltage switching and / or zero current switching can be achieved at a specific switching frequency, thereby significantly reducing switching losses. Advantageously, the transformer is operated at high frequencies, particularly at frequencies greater than or equal to 5 kHz. Especially when using SiC or GaN semiconductors, the actively switchable semiconductors are preferably operated at switching frequencies greater than or equal to 100 kHz, more preferably greater than or equal to 500 kHz, and most preferably greater than or equal to 1 MHz. GaN semiconductors also have the advantage of not exhibiting a body diode in the classical sense, as is the case, for example, with silicon or silicon carbide semiconductors due to their topology, and are therefore bidirectionally switchable.GaN semiconductors also exhibit bidirectional conductivity. The higher the operating frequency of a transformer, the more compact it can generally be. Each path of the low-voltage DC secondary side is electrically connected to a secondary winding of the transformer at its input. Each path of the high-voltage DC primary side is electrically connected to a primary winding of the transformer at its output. The turns ratio between the primary and secondary sides depends on the DC voltage of the high-voltage DC primary side and the DC voltage of one of the DC networks of the low-voltage DC secondary side. For example, the high-voltage DC primary side might have a DC voltage of 800 V and the DC network of the low-voltage DC secondary side might have a DC voltage of 48 V. The turns ratio would then be 1:800 / 48. The transformer can have a three-phase or single-phase connection on either the primary or secondary side.The transformer can have more than one three-phase or single-phase connection on the primary or secondary side. For example, the transformer can have one three-phase and one single-phase connection on the primary side and one three-phase and two single-phase connections on the secondary side. In a particularly preferred embodiment of the invention, all AC / DC converters can be disconnected from the overall system via disconnect elements, which are logic-controlled and preferably arranged on the input and output sides of the respective AC / DC converter. The disconnect elements can be active switching devices such as power switches, contactors, power transistors, or electromechanical relays. However, the disconnect elements can also be designed as passive switching devices such as fuses, which, for example, trip in the event of an overcurrent and interrupt the electrical connection.According to an advantageous embodiment of the invention, the primary-side AC / DC converter is designed as a 3-level AC / DC converter, preferably as a 3-level neutral-point converter AC / DC converter (3L-NPC). Unlike 2-level converters, 3-level converters can provide three voltage levels at the output of each string. 3L-NPCs have three strings, each string comprising four series-connected semiconductors. Clamp diodes, electrically connected to the neutral point, are integrated within each string. The strings are connected in parallel. The DC link is physically divided on the input side by two separate DC capacitors, thus providing access to the neutral point. In the 3L-NPC, all semiconductors only need to be dimensioned for half the DC link voltage. In addition to the 3L-NPC AC / DC converter, the 3L-NPC T-type AC / DC converter can also be used.This converter features controlled neutral point drive via two anti-series transistors with an anti-parallel diode. A disadvantage of this AC / DC converter is that the external semiconductors must be designed to handle the entire intermediate circuit voltage. A floating-capacitor inverter, also known as a flying-capacitor inverter, can also be used. In addition to 3-level AC / DC converters, 5-level or multi-level AC / DC converters can also be employed. In a particularly advantageous embodiment of the invention, the high-voltage DC primary side has a voltage value greater than or equal to 240 V, and the low-voltage DC secondary side has a 12 V DC network and a 48 V DC network. Both DC networks of the low-voltage DC secondary side can also have either 12 V or 48 V. The DC networks can also have other voltage values ​​less than or equal to 60 V, for example, 24 V or 36 V.Advantageously, the low-voltage DC secondary side has two 12 V DC networks and one 48 V DC network. Preferably, the converter device has two channels on the high-voltage DC primary side and three channels on the low-voltage DC secondary side. One channel of the high-voltage DC primary side preferably has a DC voltage value between 200 V and 1000 V. The other channel of the high-voltage DC primary side also preferably has a DC voltage value between 200 V and 1000 V. One channel of the low-voltage DC secondary side preferably has a DC voltage value of 12 V. Another channel of the low-voltage DC secondary side preferably has a DC voltage value of 12 V. The third channel of the low-voltage DC secondary side preferably has a DC voltage value of 48 V.The nominal total power of the converter device is preferably between 1 kW and 150 kW, particularly preferably between 5 kW and 80 kW, most preferably between 7.5 kW and 30 kW, and most preferably at 5 kW. Preferably, all bidirectional AC / DC converters have actively switchable semiconductors, preferably MOSFETs, thyristors, or IGBTs, and all unidirectional AC / DC converters have passive semiconductors, preferably diodes. Silicon (Si), silicon carbide (SiC), or gallium nitride (GaN) is preferably used as the semiconductor material. Silicon carbide is characterized by its high reverse voltage capability. Gallium nitride semiconductors have a higher electron mobility compared to silicon carbide semiconductors. This leads to higher switching speeds and lower switching losses. A disadvantage of gallium nitride semiconductors is that their reverse voltage capability is lower than that of silicon carbide semiconductors.For converter devices with high voltage ranges, a 3L NPC AC / DC converter is therefore preferably used, since in this AC / DC converter, at most half the intermediate circuit voltage is applied across each individual semiconductor. Passive semiconductors such as diodes or thyristors can also be made of one of the materials listed above. In cost-effective applications, actively switchable semiconductors and passive semiconductors are preferably silicon-based. Preferably, the energy storage device, which is electrically connected to a channel on the low-voltage DC secondary side, is designed as a lithium-ion battery. The energy storage device can also be designed as a lead-acid battery or a solid-state battery. Preferably, the capacity of the energy storage device is less than or equal to 2 kWh, and the terminal voltage of the energy storage device corresponds to the voltage of the DC network to which the energy storage device is electrically connected.The terminal voltage of the energy storage device can also be slightly lower than the voltage of the DC network to which the energy storage device is electrically connected. The energy storage device can also have a capacity greater than 2 kWh. In an advantageous embodiment of the invention, the energy storage device is directly electrically connected to one of the channels on the channel output side. The voltage of the DC network connected to the channel is fixed at the terminal voltage of the battery. A disadvantage of such an arrangement is that the battery has to compensate for voltage ripple, which can negatively affect the lifespan of the energy storage device. A capacitor connected in parallel to the battery with a lower ESR than the energy storage device can remedy this by buffering the high-frequency component. In a particularly preferred embodiment of the invention, one or more diodes are connected between the energy storage device and the channel.The battery's terminal voltage is normally slightly below the DC output voltage of the channel. If the DC voltage of the channel drops below the terminal voltage of the energy storage device, the diode begins to conduct, and the DC voltage of the channel is clamped to the terminal voltage of the energy storage device. Preferably, Schottky diodes with an extremely low forward voltage are used in such an arrangement. According to the invention, a method for operating a converter device, in particular for the reliable supply of a low-voltage DC secondary side in a vehicle in the event of a fault, comprises the following steps: detection of a fault in a channel; disconnection of the faulty channel.Supply of at least one of the DC networks via a backup energy path, wherein the backup energy path comprises two channels, the transformer, and a power source, and the transformer is arranged between the two channels of the backup energy path. In a particularly preferred method step, the fault in at least two phases of a three-phase AC / DC converter is detected in one channel of the high-voltage DC primary side, and subsequently, this AC / DC converter is disconnected from the overall system. Advantageously, the power supply of one of the DC networks is provided by the energy storage device, wherein this DC network is electrically connected to the energy storage device. Preferably, the power supply of one of the DC networks is provided by the backup energy path, which comprises the energy storage device, a channel electrically connected to the energy storage device, a channel electrically connected to this DC network, and the transformer.The supply of one or more DC networks from an energy storage device located on the low-voltage DC secondary side is referred to here and in the following as emergency operation. Emergency operation occurs when power transfer from the high-voltage DC primary side to the low-voltage DC secondary side is not possible due to a fault on the high-voltage DC secondary side. The power supply to all safety-critical components must be guaranteed at all times, even in emergency operation. For example, the driver must be able to maneuver the vehicle out of the danger zone, i.e., the roadway, to the side of the road. For this to happen, components such as the turn signals, brakes, steering, lights, and windshield wipers must remain functional.In a particularly advantageous process step, upon detection of a failure in one phase of the primary-side AC / DC converter, the faulty phase is disconnected, and the bidirectional n-phase AC / DC converter of the high-voltage DC primary-side channel switches to (n-1)-phase operation. Additionally, all non-safety-critical loads, such as heating or active body control, are switched off to conserve energy for the safety-relevant components. According to a particularly advantageous process step, the states of the semiconductors, preferably their switching behavior, and especially their output voltages, are individually monitored by means of logic.Advantageously, the condition of the converter's semiconductors is compared using AI, a digital twin, a neural network, or a stored data set, whereby the string containing a semiconductor with an abnormal reading or a defective semiconductor is disconnected. After disconnecting a string, the system enters converter protection mode. The affected n-phase AC / DC converter continues to operate in (n-1) string mode, preferably in block mode. In this mode, the converter's efficiency is lower because block commutation results in a higher harmonic content. The vehicle control system then calculates the remaining expected driving time based on the battery state and the condition of the other semiconductors.In the event of an unexpected failure of another phase of the n-phase AC / DC converter, the phase of the same AC / DC converter that was shut down due to fatigue can be restarted. According to the invention, a control unit is provided for controlling the converter device according to the invention. The control unit preferably comprises a vehicle control unit (VCU) and at least one further microcontroller (MCU). Preferably, each channel is controlled by its own microcontroller. The software of each microcontroller has been developed with safety in mind. The controller software was developed using a development toolchain such as Matlab IEC Kit and subsequently compiled into binary code with a safety-certified compiler such as the Hitex Vehicle Control Compiler. The number of microcontrollers is infinitely expandable. The microcontrollers and the VCU communicate with each other.Communication serves to exchange control variables as well as state variables, such as state commands, actual state, and target state. In particular, the microcontrollers monitor each other and all safety-critical components of the vehicle, for example, via a watchdog function. Communication between the microcontrollers is advantageously carried out via Serial Peripheral Interface (SPI). Safety mechanisms such as black channel, heartbeat, or similar are integrated into the SPI communication. A short failure reaction time is also important for control engineering. The microcontrollers communicate with the higher-level vehicle control system and / or with each other via fieldbus / CAN. The same safety mechanisms are implemented as in the previously described SPI communication.State variables, as well as measured variables and actual values ​​for diagnostic purposes, are exchanged between the microcontrollers and the vehicle control unit. When the car is started, the energy storage system undergoes a peak power performance test. The peak power can either be fed into the high-voltage battery or achieved by briefly activating consumers such as the heating or cooling system. Furthermore, emergency operation, particularly the power supply to safety-critical components during emergency operation, is tested. Additional safety-related tests can also be performed before the vehicle is put into operation. Advantageously, the converter device is designed for a vehicle, especially a motor vehicle. The vehicle is preferably configured as a purely electric vehicle.Preferably, the reference potential or negative potential or ground of all DC networks on the low-voltage DC secondary side is the vehicle body. The channel, as described above and hereafter, is a power transmission path within the converter device. Four exemplary embodiments of the present invention are described in detail below with reference to the accompanying drawing. Figure 1 shows an equivalent circuit diagram of the converter device, which has one channel on the high-voltage DC primary side and two channels on the low-voltage DC secondary side, each channel having only one path. Figure 2 shows an equivalent circuit diagram of the converter device with one channel on the high-voltage DC primary side and two channels on the low-voltage DC secondary side, each channel having two paths.Figure 3 shows an equivalent circuit diagram of the converter device, with one channel on the high-voltage DC primary side and three channels on the low-voltage DC secondary side, wherein one channel of the low-voltage DC secondary side has two paths. Figure 4 shows an equivalent circuit diagram of the converter device, with two channels on the high-voltage DC primary side and three channels on the low-voltage DC secondary side, wherein one channel of the low-voltage DC secondary side has two paths. Figure 5A shows an example of the supply of a safety-critical load. Figure 5B shows an example of the supply of a safety-critical load. Figure 6 shows a reliability block diagram of embodiment two for the safe power supply of a DC network, wherein the DC network to be safely supplied is not directly electrically connected to any power source. Figure 7 shows a flowchart of the operating states of the converter device.Identical or functionally equivalent parts or features are identified by the same reference numerals in the following detailed description of the figures. Likewise, not all identical or functionally equivalent parts or features in the figures are provided with a reference numeral. Figure 1 shows an equivalent circuit diagram of a first embodiment of the converter device 1. The converter device 1 has a high-voltage DC primary side 5 and a low-voltage DC secondary side 6. The high-voltage DC primary side 5 is galvanically isolated from the low-voltage DC secondary side 6 by a transformer 10. The high-voltage DC primary side 5 has a channel 50A, wherein the channel 50A comprises a path 60A. The channel 50A of the high-voltage DC primary side 5 can have one or more paths 60A, each path 60A being able to carry its own power flow. On the channel output side, the paths 60A of a channel 50A are electrically connected to each other.The AC / DC converter 2A0 of path 60A of channel 50A of the high-voltage DC primary side 5 is configured as a three-phase 3L NPC AC / DC converter. The AC / DC converter 2A0 can also be configured as a B6 bridge, which is also referred to as a three-phase bridge circuit. The three-phase 3L NPC AC / DC converter has three strings 23. Each string 23 has four actively switchable semiconductors 24, with the four semiconductors 24 of a string 23 being connected in series. The four semiconductors 24 of a string 23 are designated as the first to fourth semiconductors 24A-24D. The actively switchable semiconductors 24 are preferably configured as GaN MOSFETs. The actively switchable semiconductors 24 can also be configured as other semiconductor materials such as silicon or silicon carbide. Furthermore, the actively switchable semiconductors 24 can also be configured as IGBTs or thyristors. Antiparallel diodes 25 are connected to the actively switchable semiconductors 24.If the actively switchable semiconductors 24 already have antiparallel body diodes due to their topology, separate antiparallel diodes 25 can be omitted, provided the properties of these body diodes are sufficient. As already mentioned, the actively switchable semiconductors 24 are preferably designed as GaN semiconductors. GaN semiconductors themselves do not have a body diode, which is why diodes 25 must be arranged antiparallel to the GaN semiconductors. GaN semiconductors also have the advantage that they can be blocked in both directions due to the lack of a body diode. A DC link 27 is provided on the input side. The DC link 27 is physically separated by two DC capacitors 28, so that a neutral point 29 is formed.The four actively switchable semiconductors 24 connected in series can be subdivided into outer actively switchable semiconductors 26A and middle actively switchable semiconductors 26B, which are referred to below simply as outer semiconductors 26A and middle semiconductors 26B. The outer semiconductors 26A are those semiconductors 24 that are directly electrically connected to the DC link 27, wherein the first semiconductor 24A is directly electrically connected to the positive potential of the DC link 27 and the fourth semiconductor 24D is directly electrically connected to the negative potential of the DC link 27. The second semiconductor 24B is directly electrically connected to the first semiconductor 24A and the third semiconductor 24C is directly electrically connected to the fourth semiconductor 24D. A first diode 80 is electrically connected on the cathode side between the first and second semiconductors 24A and 24B.The anode of the first diode 80 is electrically connected to the neutral point 29. A second diode 81 is electrically connected to its anode between the third and fourth semiconductors 24C, 24D. The cathode of the second diode 81 is electrically connected to the neutral point 29. The cathode of the second diode 81 is electrically connected to the anode of the first diode 80. The output of a string 23 is formed between the second and third semiconductors 24B, 24C of a string 23. The DC link 27 is preferably defined by the terminal voltage of a high-voltage battery 45. The high-voltage battery 45 preferably has a DC voltage value greater than or equal to 800 V. The high-voltage battery 45 can also have a DC voltage value less than 800 V, for example, 400 V or 200 V. The high-voltage battery 45 is preferably a lithium-ion battery. The high-voltage battery 45 can also be designed as a solid-state battery.The DC voltage of the high-voltage battery 45 is converted into an approximately sinusoidal AC voltage signal by the three-phase AC / DC converter 20A of the high-voltage DC primary side 5. The outputs of the AC / DC converter 20A of the high-voltage DC primary side 5, which is preferably designed as a 3L NPC AC / DC converter, are electrically connected to the primary windings 11 of the transformer 10. The primary winding 11 of the transformer 10 is preferably connected in a star configuration. The primary winding 11 of the transformer 10 can also have any other winding configuration, for example, a delta configuration. The transformer 10 is preferably designed as a toroidal transformer or as a double-E type transformer. The transformer 10 is preferably designed as a high-frequency transformer. The transformer 10 has a three-phase connection on the primary side and two single-phase connections on the secondary side.On both the primary and secondary sides, the transformer 10 has, for each phase 23, a capacitor 82 connected in series with the primary and secondary windings 11, 12, and an inductor 83 connected in series with the primary and secondary windings 11, 12, thus forming a CLLC topology. The capacitors 82 and inductors 83 are selected such that zero voltage switching and / or zero current switching occurs at a certain switching frequency. It is advantageous not to include additional inductors 83 for the CLLC topology. In most cases, the leakage inductance of the primary and secondary windings 11, 12 of the transformer 10 is sufficiently large. The capacitors 82 are then selected such that zero voltage switching and / or zero current switching occurs at one or more switching frequencies. The low-voltage DC secondary side 6 has two channels 55A, 55B. Each channel 55A, 55B has a path 65A, 65B.Each path 65A, 65B is electrically connected on the path input side to a secondary winding 12 of the transformer 10. An AC / DC converter 30A of path 65A of channel 55A is configured as a full bridge. A full bridge has four actively switchable semiconductors 24. A full bridge has two strings 23, each with two actively switchable semiconductors 24 connected in series. The other AC / DC converter 30B of the other path 65B of the other channel 55B is preferably also configured as a full bridge. GaN MOSFETs are preferably used as the actively switchable semiconductors 24. The AC / DC converters 30A, 30B convert the AC voltage transmitted via the transformer 10 into a DC voltage. One or both AC / DC converters 30A, 30B can also be configured as three-phase AC / DC converters 30A, 30B in the form of a B6 bridge or as a 3L-NPC AC / DC converter.Preferably, at least one of the AC / DC converters 30A, 30B in a channel 55A, 55B of the low-voltage DC secondary side 6 is configured as a bidirectional AC / DC converter 30A, 30B. However, one of the AC / DC converters 30A, 30B can also be configured as a unidirectional converter. Both channels 55A, 55B of the low-voltage DC secondary side 6 have a capacitor at their output and thus provide a DC voltage that has the same DC voltage value as a DC network 7A, 7B electrically connected to the channel 55A, 55B. In Fig. 1, the two channels 55A, 55B on the low-voltage DC secondary side 6 have two different DC voltage values ​​at their output, and thus two DC networks 7A, 7B with different DC voltage values. One DC network, 7A, has a DC voltage of 48 V. The other DC network, 7B, has a DC voltage of 12 V.The DC voltage values ​​of the outputs of channels 55A and 55B, and thus also of the DC networks 7A and 7B, are primarily adjustable via the turns ratio of primary winding 11 to secondary winding 12. Depending on the required DC voltage value, the turns ratio is adjusted for each individual DC network 7A and 7B. Each DC network 7A and 7B is electrically connected to an energy storage device 40A and 40B, respectively. The terminal voltage of the electrically connected energy storage device 40A and 40B preferably has the same DC voltage value as the DC network 7A and 7B electrically connected to the energy storage device 40A and 40B. Alternatively, only one DC network 7A and 7B can be electrically connected to an energy storage device 40A and 40B. In the event of a fault, the other, unconnected DC network 7A and 7B is also supplied via this energy storage device 40A and 40B.For this purpose, channel 55A, 55B, which is electrically connected to the energy storage device 40A, 40B, must have an AC / DC converter 30A, 30B that allows bidirectional power flow. In embodiment one, since each channel 50A, 55A, 55B has only one path 60A, 65A, 65B, there is no difference between a channel 50A, 55A, 55B and a path 60A, 65A, 65B. Figure 2 shows the equivalent circuit diagram of a second embodiment of the converter device 1. The converter device 100 has a high-voltage DC primary side 105 and a low-voltage DC secondary side 106. The high-voltage DC primary side 105 is galvanically isolated from the low-voltage DC secondary side 106 by a transformer 110. The transformer 110 can be designed like the transformer 10 from embodiment one as a toroidal transformer or as a double-E-type transformer and / or as a high-frequency transformer.The high-voltage DC primary side 105 has a single 150A channel, and the low-voltage DC secondary side 106 has two channels, 155A and 155B. Channel 150A of the high-voltage DC primary side 106 has one 160A path. The low-voltage DC secondary side 106 has one 155A channel with two 165A paths and one 155B channel with one path. Each path 160A, 165A, and 165B has an AC / DC converter 120, 130A, 130B1, and 130B2, respectively. Channel 150 of the high-voltage DC primary side 105 preferably has a 3L NPC AC / DC converter. Channel 150 can also have a three-phase, two-level AC / DC converter. The AC / DC converter 120 is electrically connected to disconnect elements 170 on both the input and output sides. The disconnect elements 170 can be designed as contactors or fuses and, in the event of a fault, disconnect the AC / DC converter 120 from the overall system.Channel 150 of the high-voltage DC primary side 105 is electrically connected at its input to a high-voltage power source, the high-voltage power source preferably being a high-voltage battery 145. At its output, channel 150 is electrically connected to the primary winding 111 of the transformer 110. The low-voltage DC secondary side 106 has a channel 155B with two paths 165B1 and 165B2. One of these paths, 165B1, comprises a bidirectional AC / DC converter 130B1, to which disconnect elements 170 are arranged at both the input and output sides. The other path 165 of the same channel 155B comprises a unidirectional AC / DC converter 130B2. The AC / DC converter 130B2 of the other path 160B2 can also be configured as a bidirectional AC / DC converter 130B2. On the path input side, paths 165A, 165B1, and 165B2 are each electrically connected to a secondary winding 112 of the transformer 110.The secondary winding 112, which is electrically connected to the unidirectional AC / DC converter 130B2 via path 165B2, has a slightly fewer number of turns than the secondary winding 112, which is electrically connected to the bidirectional AC / DC converter 130B1 via path 165B1. The two paths 165B1 and 165B2 of the two-path channel 155B are electrically connected to each other at their outputs. The connection of the two paths 165B1 and 165B2 constitutes the output 151B of channel 155B. Path 165B2 with the unidirectional AC / DC converter 130B2 has a diode circuit 180 at its output, which can consist of one or more diodes. Both the bidirectional AC / DC converter 130B1 of one path 165B1 and the unidirectional AC / DC converter 130B2 of the other path 160B2 of the two-path channel 155B of the low-voltage DC secondary side 106 can form two, three or more strands 123.The output 151B of the two-path channel 155B is electrically connected to a DC network 107B of the low-voltage DC secondary side 106. The DC network 107B preferably has a voltage value of 12 V. The DC network 107B can also have a DC voltage value other than 12 V, for example, 24 V, 36 V, or 48 V. The low-voltage DC secondary side 106 also has a channel 155A with a single path 165A. The path 165A is electrically connected on its input side to a secondary winding 112 of the transformer 110. The path 165A of the single-path channel 155A has a bidirectional AC / DC converter 130A. Disconnect elements 170 are preferably electrically connected to the input and output sides of the AC / DC converter 130A. The 130A AC / DC converter can be configured as a 2-level or 3-level AC / DC converter. The 130A AC / DC converter can have one, two, or more 123 phases.An energy storage device 140 is electrically connected to channel 155A of the low-voltage DC secondary side 106, which forms a single path 165A. The terminal voltage of the energy storage device 140 has the same DC voltage value as the DC network 107A to which it is electrically connected. For example, the DC network 107A has a DC voltage value of 12 V. The terminal voltage of the energy storage device 140 then also has a DC voltage value of 12 V. The DC network 107A and the energy storage device 140 can also have a DC voltage value other than 12 V, for example, 24 V, 36 V, or 48 V. In the event of a fault, the high-voltage DC primary side 105 is disconnected from the low-voltage DC secondary side 106. The energy supply for all DC networks 107A, 107B of the low-voltage DC secondary side is then provided via the energy storage device 140, which is part of the low-voltage DC secondary side 106.Both channels 155A, 155B themselves have redundancy for supplying the DC network 107A, 107B, so that each channel 155A, 155B has safety level ASIL B. Because each DC network 107A, 107B can be powered by the other channel 155A, 155B, and both channels 155A, 155B have safety level ASIL B, safety level ASIL B(D) is achieved. The converter device 100 is preferably arranged within a converter housing 190. Figure 3 shows the equivalent circuit diagram of a third embodiment of the converter device 200. The converter device 200 has a high-voltage DC primary side 205 and a low-voltage DC secondary side 206. The high-voltage DC primary side 205 is galvanically isolated from the low-voltage DC secondary side 206 by a transformer 210. The transformer 210 can be designed similarly to the transformer 10, 110 in embodiment one or two.The high-voltage DC primary side 205 has a single channel 250A. Channel 250A of the high-voltage DC primary side 205 is configured identically to the single channel 150A of the high-voltage DC primary side 105 from embodiment two. The low-voltage DC secondary side 206 has three channels 255A, 255B, and 255C. Two of the channels 255A and 255B of the low-voltage DC secondary side 206 are configured identically to the previously described channels 155A and 155B of the low-voltage DC secondary side 106 from embodiment two. The third channel 255C of the low-voltage DC secondary side 206 has a single path 265C. Path 265C includes an AC / DC converter 230C. The AC / DC converter 230C is preferably bidirectional. The AC / DC converter 230C can be configured as a 2-level or 3-level AC / DC converter. The AC / DC converter 230C can be configured as a three-phase or single-phase converter.The AC / DC converter 230C, and thus the path 265C of channel 255C, is electrically connected on the path input side to a secondary winding 212 of transformer 210. Since each channel 255A-255C has at least one path 265A, 265B1, 265C, which includes a bidirectional AC / DC converter 230A, 230B1, 230C and thus allows bidirectional power flow, energy can be transferred back and forth between the DC networks 207A-207C as desired. For example, energy can be transferred from the DC network 207A with a DC voltage of 12 V to the DC network 207C with a DC voltage of 48 V and vice versa. The bidirectional AC / DC converters 230A, 230B1, 230C are electrically connected to switching elements 270 on the input and output sides, which can each disconnect the path 265A, 265B1, 265C from the overall system in case of a fault.Channel 255C is electrically connected to the DC network 207C at its output side, the DC network 207C preferably having a DC voltage of 48 V. The DC network 207C can also have a DC voltage other than 48 V. The converter device 200 is preferably arranged in a converter housing 290. Figure 4 shows the equivalent circuit diagram of a fourth embodiment of the converter device 300. The converter device 300 has a high-voltage DC primary side 305 and a low-voltage DC secondary side 306. The high-voltage DC primary side 305 is galvanically isolated from the low-voltage DC secondary side 306 by a transformer 310. The transformer 310 can be identical or similar to the transformer 10, 110, 210 from embodiments one, two, or three. The high-voltage DC primary side 305 has two channels 350A, 350B. Both channels 350A, 350B each have a path 360A, 360B.The channels 350A, 350B of the high-voltage DC primary side 305 can also have more than one path 360A, 360B. Preferably, both channels 350A, 350B are supplied by a high-voltage battery 345. The high-voltage battery 345 has a standard tap 347 and a center tap 346. The terminal voltage of the center tap 346 and the standard tap 347 is preferably between 100 V and 425 V. A bypass diode 344 is connected antiparallel to each of the battery stacks 349. If a battery stack 349 has a fault, the bypass diode 344 conducts the current and thus bypasses the faulty battery stack 349. A body diode 344 can also be connected in antiparallel to each battery cell of a battery stack 349. Alternatively, a bypass diode 344 can be connected in antiparallel to each group of battery cells connected in series.Both paths 360A, 360B of channels 350A, 350B of the high-voltage DC primary side 305 preferably have a bidirectional AC / DC converter 320A, 320B. One of the AC / DC converters 320A, 320B can have three strings 323 and the other AC / DC converter 320A, 320B can have two strings 323. Alternatively, both AC / DC converters 320A, 320B can have three strings 323. Preferably, each string 323 is configured according to the 3L-NPC topology. The AC / DC converters 320A, 320B of paths 360A, 360B of channels 350A, 350B of the high-voltage DC primary side 305 are electrically connected to disconnect elements 370 on both the input and output sides. If an AC / DC converter 320A, 320B of the high-voltage DC primary side 305 fails, power transmission via channel 350A, 350B of the high-voltage DC primary side 305, in which the faulty AC / DC converter 320A, 320B is not located, is still possible. The low-voltage DC secondary side 306 has two channels 355A, 355B.Channels 355A and 355B of the low-voltage DC secondary side 306 are configured identically to the previously described channels 155A and 155B of the low-voltage DC secondary side 106 from embodiment two, except for the missing energy storage device 140 on the low-voltage DC secondary side 105. An energy storage device can also be electrically connected to one of the channels 355A and 355B at the output side of the low-voltage DC secondary side 306. One channel 355B of the low-voltage DC secondary side 306 has two paths 365B1 and 365B2, while the other channel 355A has one path 365A. One path 365B1 of the two-path channel 355B includes a bidirectional AC / DC converter 330B1. The other path 365B1 of the same channel 355B features a unidirectional AC / DC converter 330B2. Path 365A of the single-path channel 355A features a bidirectional AC / DC converter 330A. The two-path channel 355B feeds a DC network 307B with a DC voltage of 12 V.The single-path channel 355a also feeds a DC network 307A with a DC voltage of 12 V. The converter device 300 is preferably arranged within a converter housing 390. Fig. 5A shows the power supply of a safety-critical load 430. The safety-critical load 430 is supplied by two independent channels 455A, 455B or an energy storage device 440. One of the channels 455A is electrically connected to the energy storage device 440 on the channel output side. Furthermore, the channel 455A is electrically connected to a cable 420 on the channel output side. The cable 420 and the load 430 are electrically connected to each other. A diode 460 is arranged at the end of each cable 420, so that power can only flow in one direction. Overall, the converter device 1, 100, 200, 300 for supplying a safety-critical consumer 430 has two redundancies.The system consists of two components: firstly, the energy storage device 440, and secondly, a second channel 455B, which together meet safety level ASIL B(D). Figure 5B shows the power supply to a safety-related load 430 or a standard load. The load 430 is powered by a channel 455A or an energy storage device 440. The channel 455A is electrically connected to the energy storage device 440 on the channel output side. Additionally, the channel 455A is electrically connected to a cable 420 on the channel output side. The cable 420 and the load 430 are also electrically connected to each other. A diode 460 is located at the end of the cable 420, ensuring that power can only flow in one direction. Overall, the system has redundancy in the form of the energy storage device 340, which, in conjunction with the overall topology of the converter device 1, 100, 200, 300, meets ASIL B(D).Figure 6 shows a reliability block diagram of embodiment two for the reliable power supply of a DC network 107B, wherein the DC network to be reliably supplied is not directly electrically connected to any power source 140, 145. The DC network 107B to be supplied is safety-critical, preferably with a safety requirement of ASIL B or ASIL D. The converter device 100 underlying the block diagram has three channels 150A, 155A, 155B. One channel 150A is on the high-voltage DC primary side 105 and two channels 155A, 155B are on the low-voltage DC secondary side 106. The channel 155B, which is electrically connected to the DC network 107B to be supplied, has two paths 165B1, 165B2. One path, 165B1, features an actively switchable AC / DC converter, 130B1. The other path, 165B2, features a passive AC / DC converter, 130B2.The other two channels, 150A and 155A, each have a path, 160A and 165A, respectively, with each path having an actively switchable AC-DC converter, 120A and 130A. Additionally, a power source, 140, and 145, are electrically connected to the other channels, 150A and 155A. One channel, 150A, is powered by the high-voltage battery, 145. The other channel, 155A, is electrically connected to the energy storage device, 140. Channel 155B, without a connected power source, 140 or 145, is normally powered primarily by the high-voltage battery, 145. To achieve increased reliability, channel 150A, which is connected to the high-voltage battery, has a three-phase AC / DC converter, 120. If one string 123 fails, two further strings 123 remain, which can supply energy to the low-voltage DC secondary side 106 starting from the high-voltage DC primary side.Channel 155B, without a connected power source 140, 145, can also be supplied via the energy storage device 140, which is electrically connected to the other channel 155A, preferably in the event of a failure of channel 150A, to which the high-voltage battery 45 is connected. The DC voltage value of the safety-critical DC network 107B, which is not electrically connected to any power source 140, 145, is detected by voltage sensors 195 and transmitted to the corresponding microcontrollers 196, which then coordinate the corresponding switching operations. Each actively switchable AC / DC converter 120, 130B1, 130A has its own microcontroller 196. The microcontrollers 196 communicate with each other and with the vehicle control system. In addition, the microcontrollers 196 monitor their own AC / DC converter as well as the other AC / DC converters 120, 130B1, 130A.The microcontrollers 196 can also detect a fault and immediately disconnect the faulty channel 155A, 150A, 155B or AC / DC converter 120, 130B1, 130A from the overall system via shutdown elements 170. The power-flow-oriented block diagram can also be extended to other embodiments, whereby the power flow between the primary side and the DC networks must be adapted to the corresponding converter topology. Fig. 7 shows a flowchart of the operating states of the converter device. When the vehicle is started, a functional safety test (Fusi-Test) 510 is performed. This checks whether all subsystems are functioning correctly and are ready for operation. In normal operation 520, the high-voltage battery supplies all safety-critical components and subsystems.If a microcontroller detects that a semiconductor within a phase of the n-phase AC / DC converter, located within a path of a channel on the high-voltage DC primary side, is about to fail, the corresponding phase is disconnected and the system enters converter protection mode 530. In converter protection mode 530, the high-voltage DC primary side continues to supply energy to the low-voltage DC secondary side. However, the power output is reduced and the efficiency of the power transfer is lower. If a critical fault occurs in at least two of the phases of the n-phase AC / DC converter, the AC / DC converter is disconnected from the overall system and the entire system enters emergency mode 540. The safety-critical components and subsystems are then supplied via the energy storage device located on the low-voltage DC secondary side. From converter protection mode 530 or emergency mode 540, the system enters an idle state 550 or 540 respectively.The system is transferred to an idle state, in which it is in standby mode. It is then reinitialized and restarted. Upon restarting, the aforementioned Fusi test 510 is performed, which verifies that all systems are functioning correctly again after a fault. If no fault is found, the system then transitions to normal operation 520.

[0002] Reference list 1 Converter device 5 High-voltage DC primary side 6 Low-voltage DC secondary side 7A DC mains 7B DC mains 10 Transformer 11 Primary winding 12 Secondary winding 13 Magnetic core 20 AC / DC converter (High-voltage DC primary side) 23 Strang 24 Actively switchable semiconductors 24A First semiconductor 24B Second semiconductor 24C Third semiconductor 24D Fourth semiconductor 25 Diode26A Outer Semiconductors 26B Middle Semiconductors 27 DC Link 28 DC Capacitors 29 Neutral Point 30A AC / DC Converter (Low-Voltage DC Secondary) 30B AC / DC Converter (Low-Voltage DC Secondary) 40A Energy Storage 40B Energy Storage 45 High-Voltage Battery 50A Channel (High-Voltage DC Primary) 55A Channel (Low-Voltage DC Secondary) 55B Channel (Low-Voltage DC Secondary) 60A Path (High-Voltage DC Primary) 65B Path (Low-Voltage DC Secondary) First Diode Second Diode Capacitor (CLLC) Inductor (CLLC) Converter Device (Exemplary Two) High-Voltage DC Primary Low-Voltage DC Secondary Transformer Primary Winding Secondary Winding AC / DC Converter (High-Voltage DC Primary) StrangA AC / DC converter (low-voltage DC secondary side) B1 AC / DC converter (low-voltage DC secondary side) B2 AC / DC converter (low-voltage DC secondary side) Energy storage HV battery A Channel (high-voltage DC primary side) B Output (Channel) A Channel (low-voltage DC secondary side) B Channel (low-voltage DC secondary side) A Path (high-voltage DC primary side) A Path (low-voltage DC secondary side) B1 Path (low-voltage DC secondary side) B2 Path (low-voltage DC secondary side) Switch-off elements Diode circuit Converter housing Voltage sensors Microcontroller Converter device (Exemplary embodiment three) High-voltage DC primary side Low-voltage DC secondary side Transformer Primary winding Secondary winding AC / DC converter (high-voltage DC primary side) StrangA AC / DC converter (low-voltage DC secondary side) B1 AC / DC converter (low-voltage DC secondary side) B2 AC / DC converter (low-voltage DC secondary side) Energy storage HV battery A Channel (high-voltage DC primary side) B Output (Channel) A Channel (low-voltage DC secondary side) B Channel (low-voltage DC secondary side) A Path (high-voltage DC primary side) A Path (low-voltage DC secondary side) B1 Path (low-voltage DC secondary side) B2 Path (low-voltage DC secondary side) Switch-off elements Diode circuit Converter housing Converter device (Exemplary embodiment three) High-voltage DC primary side Low-voltage DC secondary side Transformer Primary winding Secondary winding A AC / DC converter (high-voltage DC primary side) B AC / DC converter (high-voltage DC primary side) StrangA AC / DC converter (low-voltage DC secondary side) B1 AC / DC converter (low-voltage DC secondary side) B2 AC / DC converter (low-voltage DC secondary side) Bypass diode HV battery Center tap Normal tap A Channel (high-voltage DC primary side) B Channel (high-voltage DC primary side) A Path (high-voltage DC primary side) B Path (high-voltage DC primary side) A Path (low-voltage DC secondary side) B1 Path (low-voltage DC secondary side) B2 Path (low-voltage DC secondary side) Disconnect elements Converter housing Kabel Consumer Energy Storage A Kanal B Kanal Diode Fusi-Test Normal operation, Converter protection mode, Emergency operation, Idle state

Claims

Patent Claims 1. A converter device (1; 100; 200; 300), in particular for supplying a low-voltage DC secondary side (6; 106; 206; 306) in a motor vehicle, comprising: ^a high-voltage DC primary side (5; 105; 205; 305) and a low-voltage DC secondary side (6; 106; 206; 306), ^the high-voltage DC primary side (5; 105; 205; 305) and the low-voltage DC secondary side (6; 106; 206; 306) are galvanically isolated by a transformer (10; 110; 210; 310), ^the high-voltage DC primary side (5; 105; 205; 305) has at least one channel (50A; 150A; 250A; 350A, 350B), ^the low-voltage DC secondary side (6; 106; 206; 306) has at least two channels (55A, 55B; 155A, 155B; 255A, 255B, 255C; 355A, 355B; 455A, 455B), each of which feeds a DC network (7A, 7B; 107A, 107B; 207A, 207B, 207C; 307C, 307B) on the channel output side, ^each channel (50A, 55A, 55B; 150A, 155A, 155B; 250A, 255A, 255B, 255C; 350A, 350B, 355A, 355B; 455A, 455B) has at least one path (60A, 65A, 65B;160A, 165A, 165B1, 165B2; 260A, 265A, 265B1, 265B2, 265C; 360A, 360B, 365A, 365B1, 365B2), ^the paths (65A, 65B; 165A, 165B1, 165B2; 265A, 265B1, 265B2, 265C; 365A, 365B1, 365B2) of the channels (55A, 55B; 155A, 155B; 255A, 255B, 255C; 355A, 355B; 455A, 455B) of the low-voltage DC secondary side (6; 106; 206; 306) are each path-input-side with a secondary winding (12; 112; 212; 312) of the transformer (10; 110; 210; 310) electrically connected, ^each path (60A, 65A, 65B; 160A, 165A, 165B1, 165B2;260A, 265A, 265B1, 265B2, 265C; 360A, 360B, 365A, 365B1, 365B2) has at least one AC / DC converter (20A, 30B,; 30A; 120, 130A, 130B1, 130B2; 220, 230A, 230B1, 230B2, 230C; 320A, 320B, 330A, 331B1, 330B2), ^the high-voltage DC primary side (5; 105; 205; 305) has one channel (50A; 150A; 250A; 350A, 350B) with a bidirectional n-phase AC / DC converter (20A; 120; 220; 320A, 320B), where n ≥ 3, ^the low-voltage DC secondary side (6; 106; 206; 306) has at least one channel (55A, 55B; 155A, 155B; 255A, 255B, 255C; 355A, 355B; 455A, 455B) with a bidirectional AC / DC converter (30A, 30B; 130A, 130B1; 230A, 230B1, 230C; 330A, 330B1), and ^an energy storage device (40A, 40B; 140; 240; 440) is connected to at least one of the channels (55A, 55B; 155A, 155B; 255A, 255B, 255C; 355A, 355B; 455A, 455B) of the low-voltage DC secondary side (6; 106; 206; 306) with a bidirectional AC / DC converter (30A, 30B; 130A, 130B1; 230A, 230B1, 230C; 330A, 330B1) are electrically connected on the channel output side.2.Converter device (1; 100; 200; 300) according to claim 1, characterized in that at least one channel (155B; 255B; 355B) of the low-voltage DC secondary side (106; 206; 306) has at least two paths (65A, 65B; 165A), wherein the paths (165B1, 165B2; 265B1, 265B2; 365B1, 365B2) of the channel (155B; 255B; 355B) are electrically connected to each other on the path output side. Converter device (1; 100; 200; 300) according to claim 1, characterized in that each channel (55A, 55B; 155A, 155B; 255A, 255B, 255C; 355A, 355B; 455A, 455B) of the low-voltage DC secondary side (6; 106; 206; 306) has at least two paths (65A, 65B; 165A, 165B1, 165B2; 265A, 265B1, 265B2, 265C; 365A, 365B1, 365B2), wherein the paths (65A, 65B; 165A, 165B1, 165B2; 265A, 265B1, 265B2, 265C; 365A, 365B1, 365B2) of the channel (55A, 55B;. 155A, 155B; 255A, 255B, 255C; 355A, 355B; 455A, 455B) are electrically connected to each other on the path output side.

4. Converter device (1; 100; 200; 300) according to claim 2 or 3, characterized in that an AC / DC converter of one channel (155B; 255B; 355B) of the low-voltage DC secondary side (6; 106; 206; 306) is configured as a bidirectional AC / DC converter (30A, 30B; 130A, 130B1; 230A, 230B1, 230C; 330A, 330B1) and an AC / DC converter of the same channel (155B; 255B; 355B) is configured as a unidirectional AC / DC converter (130B2; 230B2; 330B2).

5. Converter device (1; 100; 200; 300) according to one of the preceding claims, characterized in that all AC / DC converters of a channel (55A, 55B; 155A, 155B; 255A, 255B, 255C; 355A, 355B; 455A, 455B) of the low-voltage DC secondary side (6; 106; 206; 306) are designed as bidirectional AC / DC converters (30A, 30B; 130A, 130B1; 230A, 230B1, 230C; 330A, 330B1).Converter device (1; 100; 200; 300) according to any one of the preceding claims, characterized in that an AC / DC converter of one channel (155B; 255B; 355B) of the low-voltage DC secondary side (6; 106; 206; 306) is configured as a three-phase AC / DC converter and an AC / DC converter, preferably the unidirectional AC / DC converter (130B2; 230B2; 330B2), of the same channel (155B; 255B; 355B) is configured as an AC / DC converter (130B2; 230B2; 330B2) with two phases (123, 223, 323).

7. Converter device (1; 100; 200; 300) according to any one of the preceding claims. characterized by the fact that all AC / DC converters (30B, 30A; 130A, 130B1, 130B2; 230A, 230B1, 230B2, 230C; 330A, 331B1, 330B2) of a channel (55A, 55B; 155A, 155B; 255A, 255B, 255C; 355A, 355B; 455A, 455B) of the low-voltage DC secondary side (6; 106; 206; 306) are three-phase AC / DC converters (30B, 30A; 130A, 130B1, 130B2; 230A, 230B1, 230B2, 230C; 330A, 331B1, 330B2).

8. Converter device (1; 100; 200; 300) according to one of the preceding claims, characterized in that three channels (255A, 255B, 255C) are formed on the low-voltage DC secondary side (206), wherein preferably each channel (255A, 255B, 255C) is electrically connected to a DC network (207A, 207B, 207C) on the channel output side. 9.Converter device (1; 100; 200; 300) according to any one of the preceding claims, characterized in that at least one channel (55A, 55B; 155A, 155B; 255A, 255B, 255C; 355A, 355B; 455A, 455B) of the low-voltage DC secondary side (6; 106; 206; 306) has three paths.

10. Converter device (1; 100; 200; 300) according to any one of the preceding claims, characterized in that the high-voltage DC primary side (305) has at least two channels (350A, 350B), each channel (350A, 350B) comprising one path (360A, 360B).

11. Converter device (1; 100; 200; 300) according to one of the preceding claims, characterized in that the high-voltage DC primary side (5; 105; 205; 305) is connected on the input side. a high-voltage battery (45; 145; 245; 345) is electrically connected.

12. Converter device (1; 100; 200; 300) according to one of the preceding claims, characterized in that the high-voltage battery (345) has a central tap (346), wherein the central tap (346) feeds one channel (350B) of the high-voltage DC primary side (305) and the normal tap (347) of the high-voltage battery (345) feeds another channel (350A) of the high-voltage DC primary side (305).

13. Converter device (1; 100; 200; 300) according to one of the preceding claims, characterized in that the primary winding (11; 111; 211; 311) and the secondary windings (12; 112; 212; 312) of the transformer (10; 110; 210; 310) are wound on a single magnetic core (13).14.Converter device (1; 100; 200; 300) according to one of the preceding claims, characterized in that all AC / DC converters (20A, 30B, 30A; 120, 130A, 130B1, 130B2; 220, 230A, 230B1, 230B2, 230C; 320A, 320B, 330A, 331B1, 330B2) are controlled by logic via switching elements (70; 170; 270; 370), and preferably on the input and output side of the respective AC / DC converter (20A, 30B, 30A; 120, 130A, 130B1, 130B2; 220, 230A, 230B1, 230B2, 230C; 320A, 320B, 330A, 331B1, 330B2) are arranged and can be disconnected from the overall system.

15. Converter device (1; 100; 200; 300) according to any one of the preceding claims. characterized in that at least one AC / DC converter (20A; 120; 220; 320A, 320B) of the high-voltage DC primary side (5; 105; 205; 305) is designed as a 3-level AC / DC converter, preferably as a 3L-NPC AC / DC converter.

16. Converter device (1; 100; 200; 300) according to one of the preceding claims, characterized in that the high-voltage DC primary side (5; 105; 205; 305) has a DC voltage value greater than or equal to 200 V and the low-voltage DC secondary side (6; 106; 206; 306) has a DC network (7A, 7B; 107A, 107B; 207A, 207B, 207C; 307C, 307B) with 12 V and a DC network (7A, 7B; 107A, 107B; 207A, 207B, 207C; 307C, 307B) with 48 V.

17. Converter device (1; 100; 200; 300) according to one of the preceding claims, characterized in that the low-voltage DC secondary side (206) has two DC networks (207A, 207B) with 12 V and one DC network (207C) with 48 V.18.Converter device (1; 100; 200; 300) according to any one of the preceding claims, characterized in that all bidirectional AC / DC converters (20A, 30A, 30B; 120, 130A, 130B1; 220, 230A, 230B1, 230C; 320A, 320B, 330A, 330B1) comprise actively switchable semiconductors (24), preferably MOSFETs or IGBTs, and that all unidirectional AC / DC converters (130B2; 230B2; 330B2) comprise passive semiconductors (24), preferably diodes.

19. Method for operating a converter device (1; 100; 200; 300), in particular for the safe supply of a low-voltage DC secondary side (6; 106; 206; 306) in a. In the event of a fault in the vehicle, the following procedures are performed: ^Detection of a fault in one channel (50A, 55A, 55B; 150A, 155A, 155B; 250A, 255A, 255B, 255C; 350A, 350B, 355A, 355B; 455A, 455B), ^Disconnection of the faulty channel (50A, 55A, 55B; 150A, 155A, 155B; 250A, 255A, 255B, 255C; 350A, 350B, 355A, 355B; 455A, 455B) from the overall system, ^Supply of at least one of the DC networks (7A, 7B; 107A, 107B; 207A, 207B, 207C; 307C, 307B) by a substitute energy path, wherein the substitute energy path comprises two channels (50A, 55A, 55B; 150A, 155A, 155B; 250A, 255A, 255B, 255C; 350A, 350B, 355A, 355B; 455A, 455B), the transformer (10; 110; 210; 310) and a power source, and the transformer (10; 110; 210; 310) is located between the two channels (50A, 55A, 55B; 150A, 155A, 155B; 250A, 255A, 255B, 255C; 350A, 350B, 355A, 355B; 455A, 455B) of the substitute energy path.20.Method for operating a converter device (1; 100; 200; 300), characterized in that the fault in at least two strands (23) of a three-phase AC / DC converter (20A; 120; 220; 320A, 320B) is detected in a channel (50A; 150A; 250A; 350A, 350B) of the high-voltage DC primary side (5; 105; 205; 305) and subsequently this AC / DC converter (20A; 120; 220; 320A, 320B) is disconnected from the overall system.

21. Method for operating a converter device (1; 100; 200; 300) according to claim 19 or 20, characterized in that the energy supply of a DC network (7A, 7B; 107A, 107B; 207A, 207B, 207C; 307C, 307B) is provided by the energy storage device. (40) is provided, wherein this DC network (7A, 7B; 107A, 107B; 207A, 207B, 207C; 307C, 307B) is electrically connected to the energy storage device (40A, 40B, 140, 240, 440).

22. Method for operating a converter device (1; 100; 200; 300) according to one of claims 19 to 21, characterized in that the power supply of one of the DC networks (7A, 7B; 107A, 107B; 207A, 207B, 207C; 307C, 307B) is provided by the substitute energy path which connects the energy storage device (40A, 40B, 140, 240, 440), a channel (55B, 55A; 155A; 255A; 455A) electrically connected to the energy storage device (40A, 40B, 140, 240, 440), and a channel (55B, 55A; 155A; 255A; 455A) connected to this DC network (7A, 7B; 107A, 107B; 207A, 207B, 207C; 307C, 307B) electrically connected channel (55A, 55B; 155A, 155B; 255A, 255B, 255C; 355A, 355B; 455A, 455B) and the transformer (10; 110; 210; 310).23.Method for operating a converter device (1; 100; 200; 300) according to one of claims 19 to 21, characterized in that upon detection of a failure of one phase (23) of the primary-side AC / DC converter (20A; 120; 220; 320A, 320B), the faulty phase (23) is disconnected and the bidirectional n-phase AC / DC converter (20A; 120; 220; 320A, 320B) of the channel (50A; 150A; 250A; 350A; 350B) of the high-voltage DC primary side (5; 105; 205; 305) switches to (n-1) phase operation.

24. Method for operating a converter device (1; 100; 200; 300) according to one of claims 19 to 22, characterized in that the states of the semiconductors (24), preferably the.

25. Output voltages of the semiconductors (24) are individually monitored by means of logic.

26. Method for operating a converter device (1; 100; 200; 300) according to any one of claims 19 to 23, characterized in that the state of the semiconductors (24) of the converter device (1; 100; 200; 300) is compared by means of an AI, a digital twin, or a stored data set, wherein the string (23) with a semiconductor (24) exhibiting an abnormal measured value is disconnected.

27. Control unit for controlling the converter device (1; 100; 200; 300) according to any one of claims 1 to 18.

28. Converter device (1; 100; 200; 300) for a vehicle, in particular for a motor vehicle, according to any one of claims 1 to 18.

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