ELECTRICAL SYSTEM OF A VEHICLE AND METHOD FOR OPERATING THE SAME

Abstract

A vehicle comprises an electrical load and an electrical system for supplying power to the electrical load. The electrical system comprises a converter, which includes at least one branch, at least one inductor, and a pyrotechnic switch between the at least one branch and the at least one inductor; a power cell coupled to the converter on a first side of the converter; a drive cell coupled to a second side of the converter; and a processor. The processor is configured to measure a voltage across a switch of the converter, determine a switch state of the switch based on the voltage, actuate the pyrotechnic switch to deactivate at least one branch that includes the switch, reduce the converter's power to a percentage of its full power, and supply the reduced power to the electrical load.

Description

[0001] The present invention relates to electrical systems in vehicles and in particular to an electrical system of a vehicle and a method for operating the same in the event that a switch is operating in a non-optimal state within a DC-DC converter (direct current / direct current converter) of the electrical system.

[0002] For background information, reference is made in advance to the publications US 6 154 381 A, DE 10 2015 214 454 A1 and DE 10 2023 122 862 A1.

[0003] From the publications US 6,154,381 A and DE 10 2015 214,454 A1, it is known to supply an electrical load and, if necessary, a drive cell from an energy cell via a converter. The converter is described as having parallel modules that are switched on or off depending on the power requirements of the drive cell / load.

[0004] A vehicle's electrical system generally includes a DC-DC converter that transfers power between a power source and a power source. The power source has a higher energy density than the power source and can therefore be used to increase the vehicle's range. The power source has a higher power density than the power source and can therefore be used to increase the vehicle's power or propulsion. Power is generally supplied from the power source to the converter. The converter transfers the power to a power cell and an electrical load, which can be used to propel the vehicle. A suboptimal switch within the converter is undesirable for the electrical system. Accordingly, it is desirable to provide an electrical system that can continue operating even if a switch within the converter is operating in a suboptimal state. SUMMARY

[0005] According to the invention, a method for operating an electrical system of a vehicle is presented, characterized by the features of claim 1.

[0006] The method comprises measuring a voltage at a switch of a converter of the electrical system, wherein the converter is coupled to a power cell on a first side of the converter and to a drive cell on a second side, wherein an electrical load is located on the second side of the converter, determining a switch state of the switch based on the voltage, disabling a branch of the converter that includes the switch, reducing a power of the converter to a percentage of a full power of the converter, and providing the reduced power to the electrical load.

[0007] In addition to one or more of the features described herein, wherein the switch is located on one branch of the converter and the switch forms an open circuit, the method further comprises disabling one branch and reducing the power to 2 / 3 of the converter's full power.

[0008] In addition to one or more of the features described herein, wherein the switch comprises a first switch on a first branch of the converter and a second switch on a second branch of the converter, and both the first switch and the second switch form open circuits, the method further comprises disabling the first branch and the second branch and reducing the power to 1 / 3 of the full power of the converter.

[0009] In addition to one or more of the features described herein, wherein the switch comprises a first switch on a first branch of the converter, a second switch on a second branch of the converter and a third switch on a third branch of the converter, and all switches form open circuits, the method further comprises disconnecting the converter from the power cell and using the drive cell to provide power to the electrical load.

[0010] In addition to one or more of the features described herein, wherein the switch closes to form a short circuit, the method further comprises closing another switch on the branch.

[0011] In addition to one or more of the features described herein, the method further comprises detecting a fault in the drive cell and isolating the drive cell from the electrical system, and detecting a fault in the power cell and isolating the power cell from the converter.

[0012] In addition to one or more of the features described herein, the method further comprises opening a pyrotechnic switch between the branch and an inductor of the converter.

[0013] According to the invention, an electrical system of a vehicle is further presented which is characterized by the features of claim 6.

[0014] The electrical system comprises a converter, a power cell coupled to the converter on one side, a drive cell coupled to the other side, an electrical load located on the other side, and a processor. The processor is designed to measure a voltage across a switch on the converter, determine the switch state based on the voltage, deactivate a branch of the converter that includes the switch, reduce the converter's power output to a percentage of its full power, and supply the reduced power to the electrical load.

[0015] In addition to one or more of the features described herein, the switch is on one branch of the converter and the switch forms an open circuit and the processor is further designed to disable one branch and reduce the power to 2 / 3 of the converter's full power.

[0016] In addition to one or more of the features described herein, the switch comprises a first switch on a first branch of the converter and a second switch on a second branch of the converter, wherein both the first switch and the second switch form open circuits, and the processor is further configured to disable the first and second branches and reduce the power to 1 / 3 of the converter's full power.

[0017] In addition to one or more of the features described herein, the switch comprises a first switch on a first branch of the converter, a second switch on a second branch of the converter, and a third switch on a third branch of the converter, all switches forming open circuits, and the processor is further configured to disconnect the converter from the power cell and use the drive cell to provide power to the electrical load.

[0018] In addition to one or more of the features described herein, wherein the switch closes to form a short circuit, and the processor is further configured to close another switch on the branch.

[0019] In addition to one or more of the features described herein, the processor is further designed to perform the detection of a fault in the drive cell and the isolation of the drive cell from the electrical system, or the detection of a fault in the power cell and the isolation of the power cell from the converter.

[0020] In addition to one or more of the features described herein, the processor is further designed to open a pyroswitch between the branch and an inductor of the converter.

[0021] Furthermore, a vehicle is described. The vehicle comprises an electrical load and an electrical system for supplying power to the electrical load. The electrical system comprises a converter comprising at least one branch, at least one inductor, and a pyrotechnic switch between the at least one branch and the at least one inductor; a power cell coupled to the converter at a first side of the converter; a drive cell coupled to a second side of the converter; and a processor. The processor is configured to measure a voltage across a switch of the converter, determine the switch state based on the voltage, actuate the pyrotechnic switch to deactivate at least one branch comprising the switch, reduce the converter's power to a percentage of its full power, and supply the reduced power to the electrical load.

[0022] In addition to one or more of the features described herein, the switch is on one branch of the converter and the switch forms an open circuit and the processor is further designed to disable one branch and reduce the power to 2 / 3 of the converter's full power.

[0023] In addition to one or more of the features described herein, the switch comprises a first switch on a first branch of the converter and a second switch on a second branch of the converter, wherein both the first switch and the second switch form open circuits, and the processor is further configured to disable the first and second branches and reduce the power to 1 / 3 of the converter's full power.

[0024] In addition to one or more of the features described herein, the switch comprises a first switch on a first branch of the converter, a second switch on a second branch of the converter, and a third switch on a third branch of the converter, all switches forming open circuits, and the processor is further configured to disconnect the converter from the power cell and use the drive cell to provide power to the electrical load.

[0025] In addition to one or more of the features described herein, the switch closes to form a short circuit, and the processor is further designed to close another switch on the branch.

[0026] In addition to one or more of the features described herein, the processor is further designed to perform the detection of a fault in the drive cell and the isolation of the drive cell from the electrical system, or the detection of a fault in the power cell and the isolation of the power cell from the converter.

[0027] The aforementioned features and advantages, as well as other features and advantages of the invention, are readily apparent from the following detailed description in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Further features, advantages and details are listed only as examples in the following detailed description, which refers to the drawings in which: Fig. 1 shows a design of a vehicle according to an exemplary design; Fig.2 shows an electrical system of the vehicle in one configuration; Fig. 3 the electrical system during another normal operation or drive process; Fig. 4 shows a detailed view of the electrical system in one embodiment; Fig. 5 shows a diagram of the electrical system with a switch that creates an open circuit in one embodiment; Fig. 6 shows a diagram of the electrical system with a switch that creates a closed circuit in one embodiment; Fig. Figure 7 shows a flowchart of a procedure for controlling the operation of the electrical system based on a fault occurring in one of the battery packs of the electrical system; Fig. 8 a flowchart of a procedure for operating the electrical system when a fault occurs in the converter; Fig. 9 a detection circuit for detecting a fault in a switch; and Fig. Figure 10 shows a detailed view of the converter in an alternative design. DETAILED DESCRIPTION

[0029] The following description is for illustrative purposes only. It is understood that in the drawings, corresponding reference symbols denote identical or equivalent parts and features.

[0030] According to an exemplary design, Fig. 1. A vehicle configuration 10 comprising a vehicle body 12 that defines at least a passenger compartment 14. The vehicle body 12 also carries various vehicle subsystems, including a drive system 16 and other subsystems to support the functions of the drive system 16 and other vehicle components, such as a brake subsystem, a suspension system, a steering subsystem, and others.

[0031] Vehicle 10 can be an electric vehicle (EV), a hybrid vehicle, or another type of vehicle. In one embodiment, Vehicle 10 is an electric vehicle comprising multiple motors and / or drive systems. It can include any number of drive units, such as one or more drive units for applying torque to the front wheels (not shown) and / or to the rear wheels (not shown). The drive units are controllable to operate Vehicle 10 in various operating modes, such as a normal mode, a high-performance mode (in which additional torque is applied), all-wheel drive (AWD), front-wheel drive (FWD), rear-wheel drive (RWD), and others.

[0032] The drive system 16, for example, is a multi-drive system comprising a front drive unit 20 for driving the front wheels and rear drive units for driving the rear wheels. The front drive unit 20 includes a front electric motor 22 and a front inverter 24 (e.g., front power inverter module or FPIM), as well as other components such as a cooling system. A left rear drive unit 30L includes a left rear electric motor 32L and a left rear inverter 34L. A right rear drive unit 30R includes a right rear electric motor 32R and a right rear inverter 34R. The front inverter 24, the left rear inverter 34L, and the right rear inverter 34R (e.g., power inverter units or PIMs) each convert the DC power from a high-voltage battery system 40 into multiphase (e.g., two-phase, three-phase, six-phase, etc.) power.) AC power to drive the front electric motor 22, the left rear electric motor 32L and the right rear electric motor 32R.

[0033] As in Fig. As shown in Figure 1, the drive systems are equipped with separate electric motors. However, the designs are not so limited. Instead of separate motors, for example, several drives can be provided by a single machine that has multiple sets of windings that are physically independent.

[0034] As in Fig.As shown in Figure 1, the drive systems are configured such that the front electric motor 22 drives the front wheels (not shown) and the left rear electric motor 32L and the right rear electric motor 32R drive the rear wheels (not shown). However, the configurations are not limited in this way, as there can be any number of drive systems and / or motors at different locations (e.g., one motor for each wheel, two motors per axle, etc.). Furthermore, the configurations are not limited to a dual drive system, as they can be used with a vehicle that has any number of motors and / or power inverters.

[0035] In the drive system 16, the front drive unit 20, the left rear drive unit 30L, and the right rear drive unit 30R are electrically connected to the battery system 40. The battery system 40 can also be connected to other electrical components (also referred to as "electrical loads"), such as the vehicle electronics (e.g., via an auxiliary power module or APM 42), heaters, cooling systems, and others. The battery system 40 can be configured as a rechargeable energy storage system (RESS).

[0036] In one embodiment, the battery system 40 comprises a plurality of separate battery arrangements, each of which can be charged independently and used to independently power one or more drive systems. For example, the battery system 40 comprises a first battery arrangement, such as a first battery pack 44 connected to the front inverter 24, and a second battery pack 46. The first battery pack 44 comprises a first plurality of battery modules 48, and the second battery pack 46 comprises a second plurality of battery modules 50. Each of the first plurality of battery modules 48 and of the second plurality of battery modules 50 comprises a number of individual cells (not shown).

[0037] Each of the front electric motors 22, the left rear electric motor 32L, and the right rear electric motor 32R is a three-phase motor with three-phase motor windings. However, the configurations described here are not so restricted. For example, the motors can be any multi-phase machines powered by multi-phase inverters, and the drive units can be implemented using a single machine with independent winding sets.

[0038] The battery system 40 and / or the drive system 16 comprises a switching system with various switching devices for controlling the operation of the first battery pack 44 and the second battery pack 46 and for selectively connecting the first battery pack 44 and the second battery pack 46 to the front drive unit 20, the left rear drive unit 30L, and the right rear drive unit 30R. The switching devices can also be actuated to selectively connect the first battery pack 44 and the second battery pack 46 to a charging system. The charging system can be used to charge the first battery pack 44 and the second battery pack 46 and / or to supply power to the first battery pack 44 and / or the second battery pack 46 in order to charge another energy storage system (e.g., vehicle-to-vehicle (V2V) and / or vehicle-to-everything (V2X) charging). The charging system comprises one or more charging modules.For example, a first onboard charging module (OBCM) 52 is electrically connected to a charging port 54 for charging to and from an AC system or device, such as a mains AC power supply. A second OBCM 53 can be included for DC charging (e.g., DC fast charging or DCFC).

[0039] In one embodiment, the switching system comprises a first switching device 60 that selectively connects the first battery pack 44 to the front inverter 24, the left rear inverter 34L, and the right rear inverter 34R, and a second switching device 62 that selectively connects the second battery pack 46 to the front inverter 24, the left rear inverter 34L, and the right rear inverter 34R. The switching system also comprises a third switching device 64 (also called a "battery switching device") for selectively connecting the first battery pack 44 to the second battery pack 46 in series.

[0040] Any number of different controllers can be used to control functions of the battery system 40, the switching system, and the drive units. A controller comprises any suitable processing device or unit and can utilize an existing controller, such as a drive system controller, a RESS controller, and / or controllers within the drive system. For example, a controller 65 can be incorporated to control switching and drive control operations, as discussed herein.

[0041] The vehicle 10 also includes a computer system 55, which comprises one or more processing devices 56 and a user interface 58. The computer system 55 can, for example, communicate with the charging system controller to issue commands to it in response to user input. The various processing devices, modules, and units can communicate with each other via a communication device or system, such as a Controller Area Network (CAN) or a Transmission Control Protocol (TCP) bus.

[0042] As illustrated here, vehicle 10 is an electric vehicle. In an alternative configuration, vehicle 10 could be a vehicle with an internal combustion engine, a hybrid vehicle, etc.

[0043] Fig.Figure 2 shows an electrical system 200 of the vehicle in one embodiment. The electrical system 200 comprises a first power source, such as an energy cell 202, a converter 204 (e.g., a DC-DC converter), and a second power supply, such as a drive cell 206. In one embodiment, the converter 204 can be a bidirectional, multiphase DC-DC converter. Generally, the energy cell 202 is a high-voltage power source, and the drive cell 206 is a low-voltage power source. The energy cell 202 is located on a first side (high-voltage side) of the converter 204, and the drive cell 206 is located on a second side (low-voltage side). The drive cell 206 is directly connected to an electrical load 230, while the energy cell 202 is isolated from the electrical load by the converter 204.

[0044] A first contactor 210 connects the energy cell 202 to a positive high-voltage bus 212, and a second contactor 214 connects the energy cell to a negative high-voltage bus 216. Similarly, a third contactor 218 connects the drive cell 206 to a positive low-voltage bus 220, and a fourth contactor 222 connects the drive cell 206 to a negative low-voltage bus 224. A pre-charge switch 226 and a pre-charge resistor 228 are located on a branch that is parallel to the third contactor 218. An electrical load 230 is connected via the positive low-voltage bus 220 and the negative low-voltage bus 224.

[0045] A first detection circuit 232 is connected between the positive high-voltage bus 212 and the negative high-voltage bus 216 and can detect voltages at the power cell 202. A second detection circuit 234 is connected between the positive low-voltage bus 220 and the negative low-voltage bus 224 and can detect voltages at the drive cell 206.

[0046] Fig. Figure 2 shows the electrical system 200 during another normal operating condition. The voltage at the power cell 202 is converted to a low voltage by the converter 204. This low voltage can be used at the electrical load 230. During normal operation, the first contactor 210, the second contactor 214, the third contactor 218, and the fourth contactor 222 are closed, allowing both the power cell and the energy cell to supply power to the electrical load 230. This results in the current flow 236 as shown.

[0047] Fig. Figure 3 shows the electrical system 200 during another normal operation or a drive operation. The first contactor 210 and the second contactor 214 are open, while the third contactor 218 and the fourth contactor 222 are closed, thus removing the power cell 202 from the circuit, while the drive cell 206 is connected to the circuit. This results in the current flow 302 as shown.

[0048] Fig.Figure 4 shows a detailed view 400 of the electrical system 200 in one embodiment. The converter 204 comprises a first branch 402a, a second branch 402b, and a third branch 402c. These branches extend between the positive high-voltage bus 212 and the negative high-voltage bus 216 and are arranged in parallel to each other. The first branch 402a comprises a first switch S1 and a second switch S2 in series. The second branch 402b comprises a third switch S3 and a fourth switch S4 in series. The third branch 402c comprises a fifth switch S5 and a sixth switch S6 in series. A first midpoint 404a between the first switch S1 and the second switch S2 is connected to the low-voltage side via a first inductor L1. A second midpoint 404b between the third switch S3 and the fourth switch S4 is connected to the low-voltage side via a second inductor L2.A third center point 404c between the fifth switch S5 and the sixth switch S6 is connected to the low voltage side via a third inductor L3.

[0049] Fig. Figure 5 shows a diagram 500 of the electrical system 200 with a switch that creates an open circuit, in one embodiment. The open circuit of any switch of the converter can be controlled using the circuit of Fig.9 can be diagnosed, as revealed here. For illustration, the first switch S1 is the open-circuit switch. If the first switch S1 is diagnosed as forming an open circuit, the second switch S2 can be set to an open state (i.e., open circuit), thereby removing the first branch 402a from the circuit and isolating the first inductor L1 from the energy cell 202. Current can continue to flow through the second branch 402b and the third branch 402c. A resulting current loop 502 is shown. Although the open-circuit condition is explained in relation to switch S1, it is understood that any switch forming an open circuit in a particular branch of the converter can be rectified by opening the other switch on that particular branch.

[0050] Fig.Figure 6 shows an embodiment of a diagram 600 of the electrical system 200 with a switch that creates a short circuit. For illustrative purposes, the short-circuit switch is the first switch S1. If a short circuit is detected at the first switch S1, the first contactor 210 and the second contactor 214 can be opened to deactivate the connection between the power cell 202 and the converter 204. As a result, current is supplied by the drive cell 206, leading to the current loop 602, which in Fig. 6 is shown.

[0051] Fig.Figure 7 shows a flowchart 700 of a procedure for controlling the operation of the electrical system 200 based on a fault occurring in one of the battery packs of the electrical system. The procedure begins in field 702. In field 704, a check of the state of the converter 204 is performed. If the converter is deactivated, the procedure continues to field 706. If the converter is not deactivated, the procedure continues to field 708. In field 706, the drive cell is used to provide power directly to the electrical load. In field 708, the energy cell provides power to the electrical load via the converter 204. From field 706 or field 708, the procedure continues to field 710.

[0052] In field 710, the electrical system is measured to detect an insulation fault. The measurement is diagnosed in field 712. If no suboptimal or fault condition is detected at the converter in field 712, the procedure continues to field 714. In field 714, a normal DC-DC conversion is performed on the converter. The procedure then returns to field 704.

[0053] If a non-optimal condition is detected at the converter upon returning to field 712, the procedure continues to field 716. In field 716, a diagnosis is performed on energy cell 202. If energy cell 202 is good (optimal condition), the procedure continues to field 718. In field 718, the contactors for drive cell 206 (i.e., the third contactor S3 and the fourth contactor S4) are opened. The procedure then returns to field 704. If, upon returning to field 716, it is determined that the energy cell is in a faulty condition, the procedure continues to field 720. In field 720, the contactors of energy cell 202 (i.e., the first contactor S1 and the second contactor S2) are opened. The procedure then continues to field 722.

[0054] In field 722, the input voltage at the converter is measured. If the input voltage is positive (Vin>0), the process returns to field 704. Otherwise, if the input voltage is zero or negative, the process continues to field 724. In field 724, the converter is deactivated. The process then returns to field 704.

[0055] Fig. Figure 8 is a flowchart 800 of a procedure for operating the electrical system when a fault occurs in the converter 204. The procedure begins in field 802, where the status of a switch in the converter (i.e., S1-S6) is detected or monitored. In field 804, a decision is made based on the switch state. If no switch fault is detected, the procedure proceeds to field 806. In field 806, a normal DC-DC conversion is performed using the converter. If a fault is detected in a switch upon returning to field 804, the procedure proceeds to field 808.

[0056] Field 808 determines the type of switch fault for the suboptimal switch. If the switch fault is open (an open circuit), the procedure continues with field 810. If the switch fault is closed (short circuit), the procedure continues with field 824.

[0057] Field 810 counts the number of branches with open circuits. If a switch on a branch creates an open circuit (i.e., a faulty branch), the procedure continues to field 812. In field 812, the switch for the faulty branch (i.e., the branch with the open circuit) is disabled. In field 814, the DC-DC converter's power output is reduced to two-thirds of its full power. This reduction is achieved by limiting the converter's target output current.

[0058] If, upon returning to field 810, the number of faulty branches is not one, the procedure continues to field 816. If, in field 816, the switches on two branches form open circuits (i.e., two faulty branches), the procedure continues to field 818. In field 818, the switches for both faulty branches are deactivated. In field 820, the DC-DC power of the converter is reduced to one-third of its full power. This reduction is achieved by limiting the converter's target output current.

[0059] If, upon returning to field 816, the number of faulty branches is not two, the procedure continues to field 822. If, in field 822, the switches on all three branches form open circuits (i.e., three faulty branches), the procedure continues to field 824. In field 824, the contactors of power cell 202 (i.e., the first contactor 210 and the second contactor 214) are opened. In field 826, the switches (i.e., switches S1-S6) of the converter are deactivated. In field 828, the drive cell is used to provide power for the electrical load and / or for propulsion.

[0060] Fig.Figure 9 shows a detection circuit 900 for detecting a fault in a switch. Switch S1 is shown for illustration. The detection circuit 900 includes a gate driver 902. The gate driver 902 can be a controller that includes a processor for operating fault logic to determine the state of switch S1. The controller can include processing circuits that may include an application-specific integrated circuit (ASIC), an electronic circuit, a processor (shared, dedicated, or group), memory that executes one or more software or firmware programs, a combinational logic circuit, and / or other suitable components that provide the described functionality.The controller may also include a non-transitory, computer-readable medium that stores instructions which are processed by one or more processors of the controller to implement the processes described herein.

[0061] A control input 904 is provided as an input for the gate driver 902. The gate driver outputs an error condition or the switch status 906. The control input 904 is used to query the switch, and the switch status 906 is output as the result of the query. The gate driver 902 provides a signal (VGout) to a gate of switch S1 and receives a saturation state (VDsat) of switch S1. VGout can be LOW or HIGH, and VDsat can be LOW or HIGH. The gate driver 902 performs an error logic operation as shown in Table 1: TABLE 1 VG_OUT VD_SAT SWITCH STATUS LOW LOW ERROR (SHORT) LOW HIGH NORMAL HIGH LOW ERROR (OPEN) HIGH HIGH NORMAL and outputs the switch status based on the results of the error logic operation.

[0062] Fig.Figure 10 shows a detailed view 1000 of the converter 204 in an alternative embodiment. A first pyroswitch P1 is located between the first midpoint 404a and the first inductor L1. A second pyroswitch P2 is located between the second midpoint 404b and the second inductor L2. A third pyroswitch P3 is located between the third midpoint 404c and the third inductor L3. The first pyroswitch P1, the second pyroswitch P2, and the third pyroswitch P3 are each connected to a pyroswitch control signal generator 1002. The pyroswitch control signal generator 1002 can receive a switch status 906 for each of the switches S1-S6 and control a corresponding pyroswitch in response to the switch status.In particular, if the switch status on any switch is not optimal (fault condition), the corresponding pyrotechnic switch can be triggered to disconnect a corresponding branch from the circuit and allow the fault-free branches to continue transmitting power (within their capacity).

[0063] Table 2 shows possible fault modes or operating modes, the measures taken for each fault mode, and the power available for the fault mode. TABLE 2 ERROR MODES MEASURES AVAILABLE POWER A switch in the DC-DC converter is open (i.e., S1 is open). Reducing the DC-DC power to 2 / 3 of the full power by limiting the DC-DC output current 0.67*P DCDC +P Antrieb Two switches (in two different branches) in the DC-DC converter are open (dhS1 and S3 open) Reducing the DC-DC power to 1 / 3 of the full power by limiting the DC-DC output current 0.33*P DCDC +P Antrieb The entire DC-DC converter forms an open circuit (all three branches are open). Open C4 and C5, use drive cells for propulsion only P Antrieb Fault in the drive sub-package, insulation loss, or other Open C1 and C2, use only energy cells for propulsion. P DCDC Errors that require an opening contactor Fault in the energy subpackage; insulation loss; or other faults requiring an opening contactor. Open C4 and C5, use drive cells for propulsion only P Antrieb

[0064] If a switch in one branch of the converter forms an open circuit, the power is reduced to 2 / 3 of the full power. The available power is therefore composed of 2 / 3 from the power of the converter (PDCDC) and 2 / 3 from the drive cell 206 (P). AntriebThe available power is comprised of the power supplied by the drive cell 206. If the switches in two (separate) branches of the converter form open circuits, the power is reduced to 1 / 3 of the full power. Therefore, the available power is composed of 1 / 3 of the converter's power plus the power supplied by the drive cell 206. If the entire converter forms an open circuit (i.e., switches on all three branches of the converter form open circuits), the first contactor 210 and the second contactor 214 are opened, and only the drive cell 206 is used for driving. The available power is the power of the drive cell 206 (P). Antrieb ).

[0065] If the drive cell 206 has a fault, the third contactor 218 and the fourth contactor 222 are opened. The available power is the power of the converter (PDCDC). If the energy cell 202 fails, the first contactor 210 and the second contactor 214 are opened, and only the drive cell 206 is used for the drive. The available power is the power of the drive cell 206 (P Antrieb ). legend

[0066] In the drawing figures, N stands for no and Y for yes.

Claims

[1] Method for operating an electrical system (200) of a vehicle (10), comprising: Measuring a voltage at a switch (S1, S2, S3) of a converter (204) of the electrical system (200), wherein the converter (204) is coupled on a first side of the converter (204) to an energy cell (202) and on a second side to a drive cell (206), wherein an electrical load (230) is located on the second side of the converter (204); Determining the switch status of the switch (S1, S2, S3) based on the voltage; Disabling one branch (402a, 402b, 402c) of the converter (204) that includes the switch (S1, S2, S3); Reducing the power of the converter (204) to a percentage of the full power of the converter (204); and Providing reduced power for the electrical load (230). [2] Method according to claim 1, wherein the switch (S1, S2, S3) is located on a branch (402a, 402b, 402c) of the converter (204) and the switch (S1, S2, S3) forms an open circuit, further comprising deactivating one branch and reducing the power to 2 / 3 of the full power of the converter (204). [3] Method according to claim 1, wherein the switch (S1, S2, S3) comprises a first switch (S1) on a first branch (402a) of the converter (204) and a second switch (S2) on a second branch (402b) of the converter (204) and both the first switch (S1) and the second switch (S2) form open circuits, further comprising disabling the first branch (402a) and the second branch (402b) and reducing the power to 1 / 3 of the full power of the converter (204). [4] Method according to claim 1, wherein the switch (S1, S2, S3) comprises a first switch (S1) on a first branch (402a) of the converter (204), a second switch (S2) on a second branch (402b) of the converter (204) and a third switch (S3) on a third branch (402c) of the converter (204) and all switches (S1, S2, S3) form open circuits, further comprising disconnecting the converter (204) from the power cell (202) and using the drive cell (206) to provide the power for the electrical load (230). [5] Method according to claim 1, further comprising one of: (i) detecting a fault in the drive cell (206) and isolating the drive cell (206) from the electrical system (200); and (ii) detecting the fault in the power cell (202) and isolating the power cell (202) from the converter (204). [6] Electrical system (200) of a vehicle (10), comprising: a converter (204); an energy cell (202) which is coupled to the converter at a first side of the converter (204); a drive cell (206) coupled to a second side of the converter (204); an electrical load (230) is located on the second side of the converter (204); and a processor designed for: Measuring a voltage at a switch (S1, S2, S3) of the converter (204); Determining the switch status of the switch (S1, S2, S3) based on the voltage; Disabling one branch (402a, 402b, 402c) of the converter (204) that includes the switch (S1, S2, S3); Reducing the power of the converter (204) to a percentage of the full power of the converter (204); and Providing reduced power for the electrical load (230). [7] Electrical system (200) according to claim 6, wherein the switch (S1, S2, S3) is located on one branch of the converter (204) and the switch (S1, S2, S3) forms an open circuit and the processor is further configured to deactivate one branch and reduce the power to 2 / 3 of the full power of the converter (204). [8] Electrical system (200) according to claim 6, wherein the switch (S1, S2, S3) comprises a first switch (S1) on a first branch (402a) of the converter (204) and a second switch (S2) on a second branch (402b) of the converter (204), and both the first switch (S1) and the second switch (S2) form open circuits, and the processor is further configured to deactivate the first branch (402a) and the second branch (402b) and reduce the power to 1 / 3 of the full power of the converter (204). [9] Electrical system (200) according to claim 6, wherein the switch (S1, S2, S3) comprises a first switch (S1) on a first branch (402a) of the converter (204), a second switch (S2) on a second branch (402b) of the converter (204) and a third switch (S3) on a third branch (402c) of the converter (204) and all switches (S1-S6) form open circuits and the processor is further configured to disconnect the converter (204) from the power cell (202) and to use the drive cell (206) to provide the power for the electrical load (230). [10] Electrical system (200) according to claim 6, wherein the processor is further configured to perform one of the following: (i) detecting a fault in the drive cell (206) and isolating the drive cell (206) from the electrical system (200); and (ii) detecting the fault in the power cell (202) and isolating the power cell (202) from the converter (204).

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