Supplying the auxiliary components with the boosted charging voltage in the case of a connection of a diode-protected charging connector
Patent Information
- Application Number
- CN202580008458.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2024-01-24
- Filing Date
- 2025-01-15
- Publication Date
- 2026-10-13
Smart Images
Figure CN122910192A_ABST
Abstract
Description
[0001] When the charging connector is connected with diode protection, the auxiliary components are powered by the boosted charging voltage. It is known that electric vehicles are equipped with high-voltage onboard electrical systems to drive electric traction drive units efficiently and with high power at high voltage. On one hand, in addition to the drive system, there are further components (auxiliary components) that also operate at high voltage levels due to their higher power requirements. On the other hand, various DC charging voltage levels have been established, especially 400 V DC charging, which is widely used in charging stations, and 800 V DC charging, which in recent years has achieved significantly higher charging power and thus greatly reduced charging time due to its higher voltage. Therefore, there are vehicles with 800 V onboard electrical systems, which supply 800 V auxiliary components. The resulting task is how to charge such vehicles comfortably and safely at existing 400 V charging stations. This task can be viewed as ensuring backward compatibility of the onboard electrical systems of vehicles with higher rated voltages, thereby enabling advantageous charging at existing charging stations with lower rated voltages.
[0002] This task is solved by the subject matter of the independent claims. Further attributes, features, implementations, and advantages can be derived from the co-existing and dependent claims, as well as the description and drawings.
[0003] A proposed solution involves equipping a connection circuit (in the sense of a vehicle power distributor) with a boost input and boost output to increase the charging voltage below the rated voltage of the vehicle battery and / or on-board electrical system. To enable auxiliary components to operate at the rated voltage of the on-board electrical system during charging, an auxiliary component terminal is connected to the boost output. For enhanced safety, the boost output (and therefore the auxiliary component terminal) is connected to the charging connector via a diode (optionally series-connected and switchable). When an 800 V vehicle battery is connected to a 400 V charging station with overvoltage protection relative to ground (e.g., a CHAdeMO compliant station with a maximum charging voltage of 500 V), an insulation fault could cause a potential shift, triggering the overvoltage protection. In this case, the diode is off, enhancing high-voltage safety until the resulting fault current decays. Therefore, the vehicle can be charged economically at a voltage below the rated voltage of the vehicle's on-board electrical system while maintaining high safety standards.
[0004] In summary, when the voltage at the charging connector needs to be increased (due to the battery being in boost mode at the battery terminals), the diode is turned off to prevent the increased voltage from triggering the charging station's overvoltage protection (a Zener diode or equivalent), which is not designed for the increased voltage. This undesirable triggering (i.e., current flow via the overvoltage protection) occurs when the potential level relative to ground shifts and becomes asymmetrical due to an insulation fault. Thus, when the vehicle is connected to a charging station with a lower (un-increased) voltage, it can be charged at the increased voltage. Simultaneously, the proposed method allows auxiliary components such as the air conditioning compressor to operate at a high rated voltage of the vehicle's onboard electrical system during charging, improving comfort without affecting the diode's cutoff function.
[0005] A vehicle electrical system connection circuit is proposed, configured to properly connect a charging connector and a battery terminal to each other. To compensate for the voltage difference between the charging connector and the battery terminal (e.g., due to different rated voltages), a boost converter, i.e., a boost DC-DC converter, can be connected. For this purpose, the connection circuit has a boost input terminal and a boost output terminal, to which an external boost converter (i.e., located outside the connection circuit, preferably inside the vehicle electrical system) can be connected. This boost converter is capable of boosting the voltage at the charging connector to a voltage suitable for charging the battery. The boost output terminal is configured to be connected to a boost input of the boost converter, and the boost input terminal is configured to be connected to a boost output of the boost converter. Thus, a boost converter can be connected that can boost the voltage at the boost input to a higher voltage at the boost output.
[0006] At least one battery switch is provided, via which the boost output terminal is connected to the battery terminal. Preferably, the connection between the boost output terminal and the battery terminal is a bipolar switch. Therefore, a first battery switch can be provided, which is located in a negative current path that connects the negative potential of the boost output terminal to the negative potential of the battery terminal; a second battery switch can also be provided, which is located in a positive current path that connects the positive potential of the boost output terminal to the positive potential of the battery terminal.
[0007] In addition, an auxiliary component terminal is provided, which is connected to the boost output terminal. Thus, the component connected to the auxiliary component terminal can be directly powered by the boosted voltage from the boost output terminal. The auxiliary component terminal is connected to the battery terminal via at least one battery switch, and therefore can also be powered using the voltage at the battery terminal. When the battery switch is closed, a voltage for charging (of the connectable battery) can be output at the battery terminal, and simultaneously, a voltage can be output at the auxiliary component terminal to power at least one auxiliary component that can be connected to the auxiliary component terminal.
[0008] The boost output terminal is connected to the charging connector via a diode in the connection circuit. Due to the connection between the auxiliary component terminal and the boost output terminal (preferably without a switch and optionally without a fuse), the auxiliary component terminal is connected to the charging connector via this diode. The diode is preferably positioned in a negative current path that connects the boost output terminal (or its negative potential) to the charging connector (or its negative potential). The conduction direction of the diode corresponds to the power flow direction from the boost output terminal to the charging connector. In particular, the conduction direction of the diode points towards the charging connector (preferably towards the negative potential of the charging connector). In other words, the conduction direction of the diode is away from the boost output terminal and / or away from the auxiliary component terminal and / or away from the battery switch (preferably away from the negative potential of each terminal and / or away from the battery switch positioned in the negative current path). The diode can reduce the current that might flow through the overvoltage protection element in the charging station (connected to the charging connector) due to a ground-related insulation fault at a very high speed; the overvoltage protection element becomes conductive when the high voltage portion or all of the battery terminals and / or boost output terminals is located between the ground potential and a potential of the charging connector due to potential displacement.
[0009] Especially in CHAdeMO charging stations that comply with the CHAdeMO standard and have a maximum charging voltage not exceeding 500 V, an overvoltage protection diode designed accordingly is connected between the ground potential and the charging voltage potential. If the voltage level at the battery terminal / boost output terminal shifts relative to the ground potential due to an insulation fault, one of the overvoltage diodes in the charging station will conduct. Due to its conduction direction and its opposite cutoff direction, the diode will very quickly reduce the relevant current flow.
[0010] A diode is positioned in a (negative) current path connection between the charging connector and the boost output terminal and / or auxiliary component terminal (as a component connected in series in this connection). This is particularly suitable for the negative potential of the terminals involved. This connection and / or current path is preferably switchable. Preferably, a diode switch is provided in series with the diode. Through this diode switch, the boost output terminal and / or auxiliary component terminal (especially its negative potential) is connected to the charging connector (especially its negative potential). The series connection of the diode and the diode switch connects the battery switch's reverse side towards the battery terminal to the charging connector, or to a path leading to the charging connector, which may have a filter and / or a charging connector switch and / or a fuse. The diode switch may be positioned between the charging connector and the diode. Alternatively, the diode may be positioned between the charging connector and the diode switch. The diode switch relates to the same potential as the diode, especially the negative potential. Preferably, the diode switch and / or the diode is positioned only in a single potential connection, rather than simultaneously in two potential connections of the connecting circuit.
[0011] As a boost converter or boost transformer, a combination of inverter and motor can be used, or a dedicated boost converter module (charging boost module) can be employed. In such embodiments, the vehicle electrical system connection circuit preferably has a boost input terminal. The boost input terminal is configured to be connected to the AC side of the inverter, or to a phase winding or neutral point of the motor connected to the AC side of the inverter. In particular, the boost input terminal can be connected to the midpoint tap of a half-bridge or part of the half-bridge of the inverter, keeping that half-bridge or part of the half-bridge in the off state. Thus, the boost input terminal is isolated from the inverter except through the current path via at least one phase motor winding (for voltage conversion). At least one of the remaining half-bridges in the inverter is driven in a pulsed manner to form a boost converter, wherein the operating switching unit is composed of at least one remaining half-bridge, and the operating inductor is composed of at least one phase motor winding. A control device can be configured to drive the inverter, and in addition to the motoring and / or generating operation mode for the motor, it also has a corresponding conversion mode in which the inverter, as described above, is used for DC voltage conversion together with at least one phase motor winding. The boost output terminal is configured to be connected to the DC side of the same inverter. The DC side of the inverter is formed by the terminals of the inverter half-bridge. The inverter can be configured as a BnC bridge, where n is twice the number of phases of the inverter (i.e., twice the number of all controlled half-bridges of the inverter). Alternatively, a dedicated operating inductor (operating reactor) can be used as an alternative to the motor winding. The boost input terminal can be formed by a single phase terminal, configured to be connected to at least one phase terminal of the inverter. In this case, the boost output terminal specifically corresponds to the DC power supply terminal of the inverter, i.e., the terminal on the DC side of the inverter. The inverter is particularly a high-voltage traction inverter.
[0012] Besides the aforementioned possibility of using an inverter and a motor (or a dedicated operating inductor) to implement a boost converter, with the connection circuit configured to connect to it, a dedicated boost converter module can also be used. This boost converter module has its own (pulse-driven) switching unit and its own dedicated operating inductor. The boost converter module has an input side and an output side, and is configured to boost the voltage starting from the input side and output the boosted (boosted) input voltage at the output side. The vehicle electrical system connection circuit can have a boost input terminal, configured to connect to the input side of such a boost converter module. The boost output terminal is preferably configured to connect to the output side of the same boost converter module. For this purpose, several switches can be provided in the connection circuit, which can disconnect a phase terminal and establish a connection between the boost converter module and the connection circuit.
[0013] In an embodiment of the connection circuit, a fuse is included. The boost input terminal is connected to the battery terminal via this fuse. To enable rapid disconnection at high currents, the fuse is preferably configured as an electronic fuse. Alternatively, the fuse can be configured as a fast-acting fusible chain. The fuse and diode are positioned in current paths of different polarities. The fuse is preferably positioned in a positive current path. The fuse is connected in series in this current path. In the current path where the fuse is located, all current flows through the fuse. The fuse is positioned in a current path that connects the boost input terminal to the battery terminal and / or charging connector on one side. The fuse is connected to one side of the battery switch (without a switch) and connected to the battery terminal. The fuse and diode are connected to different battery switches. In embodiments with both a diode and a fuse, two battery switches are provided. The fuse is positioned between the boost input terminal and the battery terminal, particularly between the positive potentials of the boost input terminal and the battery terminal. A fuse is connected between the boost input terminal and one side of the first battery switch, facing the battery terminal (or its positive potential). A fuse is also connected between the boost input terminal and the charging connector (or its positive potential). A diode is connected between the boost output terminal / auxiliary component terminal and one side of the first battery switch, facing the battery terminal (or its positive potential). A fuse is also connected between the boost input terminal and one side of the second battery switch, facing the battery terminal (or its positive potential). The current path connecting the boost input terminal to the battery terminal (positive potential) via the fuse is preferably switchable, for example, by a single fuse switch.
[0014] The connection circuit may have a fuse switch. This switch is connected in series with the fuse. The boost input terminal is connected to the battery terminal via the fuse switch. Preferably, the fuse switch connects the fuse to the battery terminal. The fuse (preferably not connected to the boost input terminal by a switch) is connected to the battery terminal (preferably at its positive potential) and, in particular, to the side of the battery switch facing the battery terminal via the fuse switch. The fuse is also connected to the charging connector via the fuse switch, particularly at its positive potential. This connection is preferably switchable (via a charging connector switch).
[0015] According to a further arrangement, the diode connects the boost output terminal to the charging connector either without a switch or via a charging connector switch. Specifically, the diode connects a potential (e.g., a negative potential) of the boost output terminal to a potential (negative potential) of the charging connector either without a switch or via a (first) charging connector switch. The boost output terminal is preferably connected to the battery terminal via a first switching element and a battery switch connected in series therewith (especially in this order). The negative potential of the boost output terminal can be connected to the negative potential of the battery terminal via the first battery switch, especially without a switch or via the first switching element. The positive potential of the boost output terminal can be connected to the positive potential of the battery terminal via a second battery switch, especially without a switch or via the second switching element. If a first and / or second switching element is provided in addition to at least one battery switch, the first and / or second switching element can be positioned between the boost output terminal and the corresponding battery switch leading to the battery terminal. The charging connector is connected to the connection point between the first and / or second switching element and at least one corresponding battery switch, preferably directly, or via a set of (preferably omnipolar) switching units, a (preferably omnipolar) filter, and / or a fuse in one or two current paths. This switching unit may have one or two charging connector switches and may be located upstream of the charging connector. The boost input terminal may be (unipolar) connected to the charging connector and / or its associated potential (e.g., positive potential) via a fuse and then via a (unipolar) charging connector switch, optionally with a fuse element between the charging connector switch and the battery terminal. The boost input terminal may be connected to the fuse device via a fuse switch, which is preferably connected to the charging connector without a switch. Alternatively, the boost input terminal may be connected to a fuse device, a subsequent fuse switch, and a fuse element (via a charging connector switch) leading to the charging connector. The end of the fuse element opposite to the charging connector is connected to the battery terminal, either directly or via a battery switch. Alternatively, the boost input terminal can be connected to the charging connector via a fuse and a subsequent fuse switch, and optionally to one end of a charging connector switch facing the charging connector. The charging connector switch can be positioned between the fuse switch and the battery terminals and / or auxiliary component terminals and / or the boost output terminal. The path from the boost input terminal (via the fuse and optional fuse switch) to the charging connector can be direct, i.e., connected to the charging connector without passing through the charging connector switch, which then leads from the charging connector and / or from this path to the battery terminals. The fuse can be connected sequentially from the boost input terminal followed by the fuse switch, or vice versa. This series connection specifically connects the boost input terminal directly to the charging connector or via a charging connector switch.
[0016] The positive potential of the boost output terminal can be connected to the battery terminal (or its positive potential) via a first switching element and a first battery switch connected in series therewith. The negative potential of the boost output terminal can be connected to the battery terminal (or its negative potential) via a second switching element and a second battery switch connected in series therewith. The connection point between the first and / or second switching elements and the corresponding first and / or second battery switches (via a charging connector switch) is connected to the charging connector. The boost input terminal (via a fuse) is connected to the current path formed between this connection point (and / or its positive potential) and the charging connector, particularly in a switchless connection. The boost output terminal and / or its negative potential are connected to this connection point (and / or its negative potential) via a diode, particularly in a switchless connection.
[0017] The connection circuit may have at least one charging connector switch. This switch connects the charging connector to the battery terminals. A first charging connector switch can connect the negative potential of the charging connector to the negative potential of the battery terminals. A second charging connector switch can connect the positive potential of the charging connector to the positive potential of the battery terminals.
[0018] The diode can be connected to the charging connector (and / or its positive potential) via a charging connector switch. Furthermore, the diode can also be connected to the battery terminals via a (first) charging connector switch, particularly to the positive potential of the battery terminals.
[0019] A further arrangement specifies that the charging connector is connected to the boost output terminal via at least one battery switch. This connection is preferably omnipolar, with one battery switch for each potential. Alternatively, the charging connector can also be connected to the battery terminal via at least one battery switch. This connection is preferably omnipolar, with one battery switch for each potential. Therefore, from the perspective of the charging connector, the at least one battery switch can be located on the side leading to the boost output terminal or on the side leading to the battery terminal.
[0020] A control device may be provided, which is connected to the switch described herein for driving, and is preferably configured to output a signal to the inverter (located outside the connection circuit). The control device may be part of the connection circuit, or it may be part of a branch of a charging on-board electrical system that includes the connection circuit and the inverter (and optionally a motor connected thereto).
[0021] The above method can be implemented using a charging on-board electrical system branch. This branch is equipped with an on-board electrical system connection circuit (as described herein) and an inverter (as described herein). The DC side of the inverter is connected to the boost output terminal. The AC side of the inverter is configured for connection to a motor. Alternatively, a motor can be incorporated into the charging on-board electrical system branch, for example, when its inductance is used as the operating inductor in the boost converter. The AC side of the inverter is connected to a boost input terminal of the on-board electrical system connection circuit (directly or via a switch, such as a star switch for the motor). Alternatively, the charging on-board electrical system branch has a (dedicated) boost converter, such as the boost converter described herein. The output side of the boost converter is connected to the boost output terminal. The input side of the boost converter is connected to a boost input terminal of the on-board electrical system connection circuit.
[0022] In one embodiment, the charging on-board electrical system branch includes an inverter, and particularly uses the inverter for boost conversion. The charging on-board electrical system branch may have a control device configured to: in driving mode, drive the inverter directly or indirectly in a pulse mode to generate a rotating magnetic field in the connected motor. The control device may also be configured to: in fault condition, keep the switches of the inverter and the on-board electrical system connection circuit directly or indirectly in a continuously open state. In a preferred embodiment, the control device directly or indirectly drives the inverter, causing part or more preferably all half-bridges to be closed. In other words, the control device is preferably configured to drive the inverter to generate an active short-circuit, particularly by turning on (partially or completely) the half-bridges. A bridge short-circuit indicates that the half-bridge series transistors are ON, thereby turning on the inverter and / or the half-bridges. This bridge short-circuit acts on the input voltage of the inverter, i.e., on the potentials of the boost output terminals, and shorts them. If a dedicated boost converter is connected to the boost output terminal, the control device is configured to close the corresponding switch of the boost converter to actively generate the short circuit. This accelerates and ensures the triggering of any potential fuses. The control device is configured to output such a signal to the inverter and, in particular, has a corresponding drive output.
[0023] The control device is also configured to: in the boost state, drive the inverter in a switching manner in a timing sequence, so that it performs boost conversion as a switch of the boost converter, wherein the inverter and at least one phase of the motor winding connected thereto constitute the boost converter.
[0024] The vehicle electrical system may also include a battery with a fixed rated voltage or with different rated voltages through parallel / series configurations of battery strings. The battery is particularly a high-voltage battery with a fixed or configurable rated voltage of 800 V (including a variation range of ±5, 10, or 20%). If the battery is not configurable, the boost input terminal (which may be via a fuse) and the boost output terminal (and / or its negative potential) are connected to the charging connector, and this connection does not pass through a charging connector switch. Instead, the current paths to the boost input and output terminals and to the battery terminals both originate from the charging connector, with only the latter current path having a battery switch. If the battery is configurable, the boost input terminal (which may be via a fuse) and the boost output terminal (and / or its negative potential) are connected to the battery terminals, and this connection does not pass through a charging connector switch. Instead, the current paths extending from the charging connector initially pass through charging connector switches, which are connected to the battery terminals and diodes and / or fuses on their side opposite to the charging connector.
[0025] The components described herein, particularly diodes, fuses and fuse elements, and terminals, are all high-voltage components with a rated voltage higher than 60 V, particularly at least 200 V, 400 V, or 800 V. The terminals described herein are preferably high-power terminals with a current carrying capacity of at least 10 A, 50 A, or 100 A. Battery terminals, auxiliary component terminals, charging connectors, and boost output terminals are preferably bipolar structures, each having a negative potential and a positive potential. These terminals are DC terminals. The boost input terminal is preferably unipolar. The switches described herein are preferably motor electrical switches such as relays, but can also be implemented as semiconductor switches. Unless otherwise stated, the switches described herein are unipolar switches and / or on / off switches. The fuse is disposed in a current path between the boost input terminal and the remaining circuitry. The fuse element is disposed upstream of the charging connector, particularly between one side of the charging connector and the other side of the battery terminal and / or boost input terminal. The fuse element is preferably a fusible chain, but can also be implemented as an electronic fuse. The fuse is preferably an electronic fuse, but can also be implemented as a fast-acting fusible chain. The charging connector can be configured according to the charging standards for electric vehicles, or connected to a plug-in connection element configured according to the charging standards.
[0026] The vehicle electrical system connection circuitry is preferably housed in one housing; the inverter, motor, and (if applicable) battery are preferably housed in another housing. Other embodiments specify that the vehicle electrical system connection circuitry and the inverter are housed in the same housing. The aforementioned terminals are particularly embedded in the housing wall. These terminals can be plug-in terminals, or connections formed by through conductor traces, through busbars, or other interconnected busbars.
[0027] Diodes and (if present) fuses can be designed for maximum current load (pulse current load, continuous current load), which is less than the current load rating of the battery switch (or charging connector switch). This also applies to switching elements located between the boost output terminals and the battery switch, i.e., switching elements in the same current path as the diodes and (if present) fuses. In particular, diodes and (if present) fuses are rated for the (lower) load power of auxiliary components, and the auxiliary component terminals are also rated for that power, which is lower than the rating of components located between the boost output terminals and the battery terminals (and / or between the load terminals and the battery terminals).
[0028] As a diode, a diode device (with exactly one PN junction or Schottky junction) can be used, or a switch (semiconductor switch or motor switch) can be used that is open in one current direction of the power path and driven to close under the reverse voltage across the switch, i.e., a switch with diode function.
[0029] Figures 1 and 2 are used to illustrate various implementations of the connection circuits and vehicle electrical system branches described herein.
[0030] First, the same components in each figure are described, and these components therefore have the same reference numerals. Figures 1 and 2 each show a connection circuit VS, which has a boost output terminal IA, a battery terminal BA, and a charging connector LA. In addition, the connection circuit VS has an auxiliary component terminal HA. These terminals are all negatively charged. With a positive potential. One boost input terminal PA is unipolar and has a positive potential.
[0031] Components located outside the connection circuit VS are connected to the boost input terminal PA and the boost output terminal IA. These components include the inverter INV and the motor EM. The inverter INV has an AC side connected to the motor EM. The boost input terminal PA is also connected to this AC side. The DC side of the inverter INV is connected to the boost output terminal IA. Thus, a voltage can be applied to the AC side of the inverter INV via the boost input terminal PA, particularly to the windings of the motor EM connected thereto. By pulse-driving the inverter INV, the inductance of the motor EM can operate as a boost converter together with the inverter INV. The example shown relates to a scheme in which the inverter and motor operate as a boost converter; however, a dedicated boost converter can also be used instead of these two components.
[0032] Inside the connection circuit VS, the boost output terminal IA is connected to the auxiliary component terminal HA in a two-pole configuration. This connection is switchless but can be fitted with a fuse and / or filter. Furthermore, the boost output terminal IA is connected to the battery terminal BA via two battery switches B1 and B2 (one switch for each potential, i.e., a two-pole arrangement). The first battery switch B1 connects the positive potential of the boost output terminal IA to the positive potential of the battery terminal BA. The second battery switch B2 connects the negative potential of the boost output terminal IA to the negative potential of the battery terminal BA. When a (raised) voltage exists at the boost output terminal IA, this voltage can be transferred to the auxiliary component terminal HA and the battery terminal BA. This can be used to power the auxiliary component via the auxiliary component terminal HA and / or charge the battery via the battery terminal BA.
[0033] The charging connector LA is connected to the battery terminal BA in a two-pole configuration. Charging connector switches C1 and C2 are arranged in a two-pole configuration (i.e., one switch for each potential). A first connection point V1 is formed between the negative potential of the charging connector LA and the first charging connector switch C1. A second connection point V2 is formed between the positive potential of the charging connector LA and the second charging connector switch C2. Figures 1 and 2 share this feature, but in Figure 1, connection points V1 and V2 are connected on the side of the charging connector switches C1 and C2 facing the charging connector LA, while in Figure 2 they are connected on the side facing the battery terminal BA. Both figures share that the first connection point V1 is connected to the boost output terminal IA via a diode D, specifically to its negative potential.
[0034] A third connection point V3 is formed, where the negative potential of the boost output terminal IA, the negative potential of the auxiliary component terminal HA, and the diode D are connected to each other. The conduction direction of the diode D is away from the third connection point V3, specifically pointing towards the charging connector LA. Consequently, the cutoff direction of the diode D is away from the charging connector LA, specifically pointing towards the third connection point and / or towards the boost output terminal IA. The connection between the first and third connection points V1 and V3 includes not only a diode D but also a diode switch M2 connected in series with the diode. The diode D and the diode switch M2 are connected in series and are both arranged between points V3 and V1. In the illustrated embodiment, the diode D is located after the third connection point V3, and the diode switch M2 connects the diode D to the first connection point V1. The diode switch and the diode can also be used in reverse order. If the diode D is not connected between the negative potential of the charging connector LA and the boost output terminal IA, but between positive potentials, then the diode can be set to the opposite direction.
[0035] The boost input terminal PA is connected to the charging connector LA via an electronic fuse EF (generally: a fuse device EF). In Figure 1, this connection is direct and leads to the charging connector LA only via a fuse device switch M1. In Figure 2, the connection starts from the boost input terminal PA, passes through the electronic fuse EF, and then through a subsequent fuse device switch M1 to the second connection point V2. This point V2 is connected to the charging connector LA via the second charging connector switch C2. It is illustrated that the boost input terminal PA is first connected to the fuse device switch M1 via the electronic fuse EF, but this order can also be reversed. The fuse device switch M1 shown is directly (Figure 1) or via the second charging connector switch C2 (… Figure 2 ) Leads to the charging connector LA.
[0036] In Figure 1, diode D is connected to the negative potential of charging connector LA via diode switch M2, but this connection does not pass through either charging connector switch C1 or C2. Instead, diode D and its series-connected diode switch M2 are connected to battery terminal BA (more precisely, to its negative potential) via the first charging connector switch C1. Similarly, the path from the self-contained terminal PA, via the electronic fuse EF and the fuse switch M1, also leads to the charging connector (and / or its positive potential +), without passing through either charging connector switch C1, C2. Therefore, in Figure 1, the electronic fuse EF and diode D lead directly to the charging connector LA and via the (bipolar) charging connector switches C1, C2 to the battery terminal BA. In Figure 2, the opposite is true: there, diode D and electronic fuse EF are bipolarly connected to the charging connector LA via charging connector switches C1, C2, while the connection to the battery terminal BA is, in many embodiments, direct (especially switchless) (or via alternatively placed battery switches B1', B2').
[0037] In Figure 1, the second charging connector switch C2 is connected to the battery terminal BA (and / or its positive potential +) via a fuse element SI, which is configured as a fusible chain. Furthermore, the connection between charging connector switches C1 and C2 leads to the battery terminal BA via a filter F. In Figure 2, the connection originating from diode D and / or electronic fuse EF leads to charging connector switches C1 and C2 via a fuse SI (located in the positive current path) and a filter F. These switches lead directly (especially without switches) to the charging connector LA.
[0038] In addition to the third connection point V3, which is the starting point of the current path including diode D, Figures 1 and 2 also show a fourth connection point V4, which connects the positive potential of the boost output terminal IA to both the auxiliary component terminal HA and the first battery switch B1. Therefore, the third and fourth connection points V3 and V4 are connected to the boost output terminal IA without switches, and are connected to the battery terminal BA via battery switches B1 and B2. This connection is a two-pole structure.
[0039] The two diagrams also show the fifth and sixth connection points, V5 and V6, which are located on the side of battery switches B1 and B2 facing the battery terminal BA. A two-pole current path (+ and) is drawn from this connection point. The path leads to the charging connector LA via charging connector switches C1 and C2. Diode D and / or electronic fuse EF are connected in this current path via connection points V1 and V2.
[0040] In the first embodiment, no other switches besides switches B1 and B2 are provided between the boost output terminal IA and the battery terminal BA. A path leading from the battery terminal to the charging connector LA is provided, which, apart from the charging connector switches C1 and C2 and the filter F, has only one single-pole fuse SI. This fuse SI is a single fuse element and / or a fuse chain. In this embodiment, a battery with a rated voltage higher than the charging voltage at connector LA can be connected to the battery terminal BA. For example, an 800 V battery can be connected to the battery terminal BA, and a charging station, for example, with a 400 V voltage can be connected to the charging connector LA. For voltage matching, switches C1 and C2 are opened, and the charging voltage is applied to the boost input terminal PA via the electronic fuse EF and the fuse device switch M1. The motor EM, outside the connection circuit, and the corresponding inverter INV operate as a boost regulator / boost converter, thus providing a higher voltage corresponding to the higher battery rated voltage at the boost output terminal IA at the battery terminal BA connected to it. Furthermore, in Figure 1, the auxiliary component terminal HA is connected to the boost output terminal IA, so a boosted voltage can be provided there during charging.
[0041] This allows power to be supplied to auxiliary components that can be connected to terminal HA. To charge the battery that can be connected to terminal BA, switches B1 and B2 are closed. If an insulation fault occurs that causes a displacement of the potential level of the 800V battery at terminal BA relative to ground, diode D can prevent the battery from entering the charging station via the overvoltage element (on one side, a high voltage +). The current generated between the other side and the ground potential.
[0042] To enable direct charging, switches C1 and C2 are closed when the charging station connected to terminal LA and the battery BA are in the same voltage range. This situation occurs when the 800 V battery at terminal BA needs to be charged by the 800 V charging station connected to terminal LA. Therefore, the circuit in Figure 1 is also backward compatible.
[0043] Figure 2 illustrates an embodiment of connecting a configurable battery to terminal BA, whose rated voltage may be equivalent to the rated voltage of charging connector LA (even if this voltage is only 400 V) or equivalent to a higher voltage level, such as 800 V, depending on the battery configuration. In a first embodiment, battery switches B1 and B2 are connected to battery terminal BA without switching. In this embodiment, diode D is connected to battery terminal BA via switch M1, and electronic fuse EF is also connected to battery terminal BA via switch M2. Switch M2 is also referred to as a diode switch, and switch M1 is also referred to as a fuse switch. Therefore, in the first embodiment of Figure 2, there is a switchless connection between battery switches B1 and B2 and battery terminal BA, while switches, in the form of switches M1 and M2, are provided in the direction (two poles) leading to the boost input terminal and boost output terminals IA and PA.
[0044] The second embodiment of Figure 2 specifies a switchless connection between the diode D and / or the electronic fuse EF side and the battery switch side; in this case, switches M1 and M2 are absent (i.e., replaced by a fixed connection). Instead, battery switches B1 and B2 are located directly before the battery terminal BA at positions B1' and B2'. The diode and / or electronic fuse D and EF are connected to the boost output terminal IA via (two-pole switches) at positions M1' and M2'. Therefore, in the second embodiment of Figure 2, switches M1 and M2 are located at positions M1' and M2', while battery switches B1 and B2 are located at positions B1' and B2'. In this embodiment, the battery switch is thus positioned between connection points V5 and V6 and the battery terminal BA. Switching elements are positioned at positions M1' and M2' (two poles) between the boost output terminal IA and connection points V5 and V6. Because they have been moved to positions B1' and B2', the battery switches B1 and B2 shown in Figure 2 are no longer located to the left of connection points V5 and V6, but to their right. In the second embodiment, compared to the first embodiment, the battery switches are directly arranged before the battery terminal BA, as seen at positions B1' and B2', i.e., before the current path leading to the charging connector LA when viewed from the battery terminal BA. Furthermore, compared to the first embodiment, in the second embodiment, switches M1 and M2 are not directly positioned after the diodes and / or electronic fuses D and EF, but are located between one side of the battery switches B1 and B2 and / or the charging connector LA and the other side of the boost output terminal IA. Specifically, the diode switch is connected between the negative potential of the boost output terminal IA and point V5, where a diode and the charging connector (via a charging connector switch) are also connected. At point V5, a battery terminal (and / or its negative potential) is connected via a battery switch at position B2', and a boost output terminal IA (and / or its negative potential) is also connected via a switch at position M2'. A diode is connected across the switch at position M2' (without any other switches); the battery switch is located at position B2' (directly before the battery terminal BA). In this embodiment, switch M2 is not located at the position shown, but rather at position B2' between terminal BA and point V5.
[0045] Using the embodiment shown in Figure 2, charging can be performed at 800 V when switches C1 and C2 are closed and the battery connected to terminal BA also has a rated voltage of 800 V (and / or a corresponding configuration). The same applies to 400 V charging stations and batteries configured to a 400 V rated voltage. Therefore, the voltage level of the charging station can be adapted by configuring the batteries connected to or potentially connected to battery terminal BA. However, when the voltage at charging connector LA is too low, the circuit in Figure 2 can supply power to auxiliary components at a boosted voltage via auxiliary component terminal HA. This is achieved by boosting the voltage of the inverter and motor (or a dedicated boost converter module) connected to boost terminals IA and PA via switch M1 and fuse EF. If a high voltage (corresponding to the rated voltage of the auxiliary component), such as 800 V, is already present at the charging connector LA, the switches located at positions M1' and M2' can be closed to provide the same high voltage at the auxiliary component terminal HA as at the charging connector LA. Therefore, with the circuit shown in Figure 2, a high voltage or increased voltage corresponding to the rated voltage of the auxiliary component can always be provided at the auxiliary component terminal HA, whether by directly conducting the high voltage or by increasing the lower voltage at the charging connector LA. This makes it possible to supply power to the auxiliary component when charging a battery configured to 800 V at 800 V, and also when charging a battery configured to 400 V at 400 V—both in which case power is supplied with a high voltage or increased voltage corresponding to the rated voltage of the auxiliary component.
[0046] The two figures show control unit C, which simultaneously drives the inverter and the switch of the connection circuit VS. The control hierarchy is omitted for clarity. Control unit C can open all switches in case of failure, drive the inverter for energy recovery and especially for driving, and also drive the inverter in a pulsed manner, forming a boost converter with an inductor of the motor EM. In Figure 1, this boost converter is used to increase the charging voltage when charging an 800V battery at 400V, and also simultaneously powers auxiliary components with the (increased) 800V voltage. In Figure 2, the boost converter is configured to provide 800V at terminal HA when the charging connector LA is 400V and the battery connected to terminal BA is configured at its 400V rated voltage.
[0047] Control device C is preferably configured to output a signal characterizing the target battery configuration. This is particularly applicable to the embodiment of FIG2 and / or the embodiment where diode D is connected to charging connector LA via charging connector switch C1 (and fuse EF is connected to charging connector LA via another charging connector switch C2). Control device C is preferably configured to output a signal corresponding to the target configuration of the parallel configuration (battery strings) in a low-voltage charging mode (e.g., charging at 400 V). Control device C is preferably configured to, in this mode, keep the switches between connection points V1, V2 (and / or V5, V6) and auxiliary component terminals HA in the open state (especially switches B1, B2 and / or switches located at positions M1' and M2'), and output a boost signal to activate the boost converter (EM+INV or dedicated converter module). Control device C is preferably configured to output a signal corresponding to the target configuration of the series configuration (the battery string) in high-voltage charging mode (e.g., charging at 800 V, i.e., higher than the charging voltage provided in low-voltage charging mode). Control device C is preferably configured to, in this high-voltage charging mode, keep the switches between connection points V1, V2 (and / or V5, V6) and auxiliary component terminal HA closed (especially switches B1, B2 and / or switches located at positions M1' and M2'), and output a converter-inactive signal to keep the boost converter (EM+INV or dedicated converter module) in an open, inactive state. In low-voltage charging mode, if present, switches M1 and M2 are closed. In high-voltage charging mode, in particular, switch M1 is open.
[0048] In particular, in the embodiments of Figures 1 and 2, it is specified that when a high-voltage battery (e.g., 800 V) is connected to the battery terminal BA, or when the battery there is configurable and can be configured in series, the control device C sets the diode switch (switch M1) to the closed state. In this case, the control device C preferably sets at least one switch in the path parallel to the diode to the open state. This specifically relates to the corresponding charging connector switch C1 when the charging connector switch C1 is connected from the diode to the battery terminal BA, and the corresponding switch B2 and / or a switch located at position M2' when the diode D is connected to the charging connector LA via the first charging connector switch C1. Thus, in the event of an insulation failure, the diode can function as a cutoff as described above, because when the diode is open, there is no closed parallel path for current to flow due to potential displacement and overvoltage protection on the charging station side. Preferably, the control device C is configured to set at least one switching state of the aforementioned switch such that when charging at a voltage lower than the battery's rated voltage (i.e., when the boost converter is active), the charging current must be guided through the diode; and the current path bypassing the diode is disconnected when the diode is in the closed state (by means of a switch).
[0049] In the embodiment shown in Figure 2 and / or in the embodiment where diode D is connected to charging connector LA via charging connector switch C1 (and fuse EF is connected to charging connector LA via another charging connector switch C2), connection points V1 and V5 are the same, and connection points V2 and V6 are the same. Under the same conditions, their potentials and especially their characteristics (e.g., location) are the same and can be transferred to each other.
[0050] The connection circuit is transformerless, meaning it is not electrically isolated.
Claims
1. A vehicle electrical system connection circuit (VS) comprising a boost output terminal (IA), a battery terminal (BA), a charging connector (LA), an auxiliary component terminal (HA) connected to the boost output terminal (IA), and at least one battery switch (B1, B2) for interconnecting the boost output terminal (IA) and the battery terminal (BA) via the battery switch, wherein, The connection circuit (VS) includes a diode (D) that connects the boost output terminal (IA) to the charging connector (LA) via the diode (D), and the conduction direction of the diode (D) is consistent with the power flow direction from the boost output terminal (IA) to the charging connector (LA).
2. The vehicle electrical system connection circuit (VS) as claimed in claim 1, further comprising a diode switch (M2) connected in series with the diode (D), via which the boost output terminal (IA) is connected to the charging connector (LA).
3. The vehicle electrical system connection circuit (VS) as claimed in claim 1 or 2, further comprising a boost input terminal (PA) configured to be connected to the AC side of an inverter (INV), wherein the boost output terminal (IA) is configured to be connected to the DC side of the same inverter (INV); or, wherein the vehicle electrical system connection circuit (VS) includes a boost input terminal (PA) configured to be connected to the input side of a boost converter module, and the boost output terminal (IA) is configured to be connected to the output side of the same boost converter module.
4. The vehicle electrical system connection circuit (VS) of claim 3, wherein the boost input terminal (PA) is connected to the battery terminal (BA) via a fuse (EF), the fuse (EF) being configured as a fast-acting fuse chain or an electronic fuse.
5. The vehicle electrical system connection circuit (VS) as claimed in claim 4, further comprising a fuse switch (M1) connected in series with the fuse (EF), via which the boost input terminal (PA) is connected to the battery terminal (BA).
6. The vehicle electrical system connection circuit (VS) as claimed in claim 1, wherein the diode (D) connects the boost output terminal (IA) to the charging connector (LA) without a switch or via a charging connector switch (C1), and the boost output terminal (IA) is connected to the battery terminal (BA) via a first switching element (M1') and a battery switch (B1') connected in series therewith.
7. The vehicle electrical system connection circuit (VS) as claimed in any of the preceding claims, comprising at least one charging connector switch (C1, C2) via which the battery terminal (BA) is connected to the charging connector (LA).
8. The vehicle electrical system connection circuit (VS) of claim 7, wherein the diode (D) is connected to the charging connector (LA) via the charging connector switch (C1), or the diode (D) is connected to the battery terminal (BA) via the charging connector switch (C1).
9. The vehicle electrical system connection circuit (VS) as claimed in any of the preceding claims, wherein the charging connector (LA) is connected to the boost output terminal (IA) via at least one battery switch (B1, B2), or the charging connector (LA) is connected to the battery terminal (BA) via at least one battery switch (B1', B2').
10. A charging vehicle electrical system branch, comprising a vehicle electrical system connection circuit (VS) as described in any of the preceding claims, wherein, The charging on-board electrical system branch includes an inverter (INV) whose DC side is connected to the boost output terminal (IA) and whose AC side is configured to be connected to the motor (EM) and to the boost input terminal (PA) of the on-board electrical system connection circuit (VS); or, the charging on-board electrical system branch includes a boost converter whose output side is connected to the boost output terminal (IA) and whose input side is connected to the boost input terminal (PA) of the on-board electrical system connection circuit (VS).
11. The charging on-board electrical system branch of claim 10, wherein the charging on-board electrical system branch includes the inverter (INV) and further includes a control device (C), the control device (C) being configured to: - In driving mode, the inverter (INV) is driven directly or indirectly in pulse mode to generate a rotating magnetic field in the motor (EM) connected thereto; - In a fault condition, the switches of the inverter (INV) and the vehicle electrical system connection circuit (VS) are directly or indirectly placed in a continuously open state; and - In boost mode, the inverter (INV) is driven in a switching manner in a timing sequence as a switch of the boost converter to perform boost conversion. The inverter and at least one winding of the motor (EM) connected thereto together form the boost converter.