DE102021122059A1 - CIRCUIT FOR ELECTRIC VEHICLES - Google Patents

Abstract

Aspects of the present invention relate to a control system (200), a vehicle electrical power system, a vehicle, a method and computer software, the method for controlling a vehicle electrical power circuit comprising determining that power is supplied to a high voltage traction bus (27) of the vehicle is to be applied, in response to determining that power is to be applied to the high voltage traction bus, causing electrical power to be applied to a DCDC converter (22), the DCDC converter so configured is that it provides a first voltage to a high voltage auxiliary bus (24) to provide a precharge current to the high voltage traction bus.

Description

TECHNICAL AREA

The present disclosure relates to an electric power circuit for a vehicle. The aspects relate to an electrical power circuit, a battery assembly, a control system, a vehicle, a method, and computer software.

BACKGROUND

Electric vehicles and hybrid electric vehicles include traction motors and traction batteries for supplying electrical energy to the traction motors.

High voltage circuits used to connect traction motors to the traction batteries are often provided with a pre-charge circuit that includes a resistor and a switch such as a switch. a relay, connected in parallel with a primary switch, e.g. B. a contactor, which connects the high voltage circuit to an electrical power source. The pre-charge circuit allows voltage equalization of the high-voltage circuit before the primary switch closes, thereby avoiding a sudden current spike when connecting the high-voltage circuit to the power source, which could otherwise cause significant stress on the primary switch.

The components of the pre-charge circuit are typically very expensive and have a fixed functionality, and these components take up space and can cause thermal problems. In addition, the pre-charging circuit can have a limited adjustability of the pre-charging point in time and the voltage range.

An object of the present invention is to obviate one or more of the disadvantages of the prior art.

SUMMARY OF THE INVENTION

Aspects and embodiments of the invention provide a control system, an electrical power system for a vehicle, a vehicle, a method and computer software according to the appended claims.

According to one aspect of the present invention, there is provided an electrical power circuit for a vehicle, the electrical power circuit having a terminal for electrical connection to a traction battery, a DCDC converter coupled to the terminal and arranged to receive a first voltage and a providing second voltage to a high voltage auxiliary power bus, comprising, a high voltage traction bus for providing electrical power to one or more traction motors, and wherein the DCDC converter is coupled to the high voltage traction bus, the DCDC converter being arranged such that in response to an indication that current is to be applied to the high voltage traction bus, provides the second voltage to the high voltage traction bus to provide a pre-charge current for the high voltage traction bus.

The precharge current may be provided by selectively coupling the output 23 to the high voltage auxiliary bus 24 so that the DCDC converter is coupled to the high voltage traction bus via the auxiliary power bus and in response to an indication that power is being supplied to the high voltage traction bus is to be applied, providing the second voltage to the high voltage auxiliary power bus to provide a pre-charge current to the high voltage traction bus.

According to one embodiment, the electrical power circuit can further comprise a first switching device connected between the clamp and the high-voltage traction bus, wherein the first switching device can be arranged in such a way that, depending on a parameter associated with the high-voltage traction bus, it electrically connects the clamp connects to the high-voltage traction bus.

Optionally, the parameter may include one of the following parameters: temperature, a magnitude of the pre-charge current, a time that the pre-charge current was supplied to the high-voltage traction bus, and a voltage of the high-voltage traction bus.

According to some embodiments, the parameter associated with the high-voltage traction bus may include the voltage of the high-voltage traction bus, and the first switching device may be configured to electrically disconnect the terminal in response to the voltage of the high-voltage traction bus being greater than a threshold voltage connected to the high-voltage traction bus.

According to some embodiments, the electrical power circuit may include the following
a second switching device connected in series with a resistive load, the second switching device and the resistive load being connected between the clamp and the DCDC converter, and a third switching device connected between the clamp and the DCDC converter in parallel with the second switching device and the resistive load is connected.

Optionally, the first voltage may include a nominal voltage in the range of 300V to 500V or 600V to 1000V and the second voltage may include a nominal voltage in the range of 300V to 500V.

According to some embodiments, the electrical power circuitry may include an onboard charger coupled to the DCDC converter, wherein the onboard charger may be configured to receive AC power and provide the first voltage to the DCDC converter, the DCDC converter configured may convert the first voltage provided by the onboard charger to provide the pre-charge current to the high voltage traction bus.

Optionally, the first voltage may be provided by a traction battery coupled to the terminal and the DCDC converter may be configured to convert the first voltage provided by the traction battery to provide the pre-charge current for the high voltage traction bus.

According to another aspect of the invention, there is provided a battery assembly including a traction battery and the electrical power circuit described above, wherein the traction battery is connected to the terminal.

Optionally, the traction battery may include a first plurality of cells, a second plurality of cells, and a battery control circuit for selectively connecting the first and second plurality of cells in series to provide a first battery voltage at a battery output in a first mode, and to selectively connect the first and second plurality of cells in parallel to provide a second battery voltage at the battery output in a second mode of operation.

Optionally, the battery control circuit can be further configured to connect the first plurality of cells to the battery output and to isolate the second plurality of cells from the battery output to provide the second battery voltage.

According to a further aspect of the invention there is provided a control system for controlling an electrical power circuit of a vehicle, the control system having input means for receiving a first signal indicative of power to be applied to a high voltage traction bus of the vehicle, output means for outputting a control signal for controlling a DCDC converter of the electrical power circuit and processing means arranged to control the output means to output the control signal in response to the first signal indicative of power to be applied to the high voltage traction bus to cause the DCDC converter to provide a first voltage to a high voltage auxiliary bus to provide a precharge current to a high voltage traction bus of the vehicle.

According to another aspect of the invention, there is provided a control system for controlling an electrical power circuit of a vehicle, the electrical power circuit comprising a high voltage traction bus for providing electrical power to one or more traction motors and a DCDC converter arranged to receiving a first voltage and providing a second voltage to a high voltage auxiliary bus, the control system comprising: input means for receiving a first signal indicative of power to be applied to a high voltage traction bus of the vehicle; outputting means for outputting a control signal for controlling the DCDC converter of the electric power circuit; and processing means arranged, in response to the first signal indicative of power to be applied to the high voltage traction bus, to control the outputting means to output the control signal to cause the DCDC converter to provide the second voltage to the high voltage traction bus to provide a pre-charge current to the high voltage traction bus of the vehicle.

According to one embodiment there is provided the control system described above, wherein the processing means, the input means for receiving the first signal indicative of power to be applied to the vehicle's high voltage traction bus, and the output means for outputting the control signal for controlling the DCDC converter the electrical power circuit comprises one or more electronic processors having an electrical input for receiving the first signal and an electrical output for transmitting the control signal, the control system further comprising an electronic storage device electrically coupled to the one or more electronic processors and instructions contains on it.

Optionally, the input means may be arranged to receive a second signal indicative of a parameter associated with the high chip voltage traction bus of the vehicle, and the processing means may be arranged to determine a parameter of the high voltage traction bus in dependence on the second signal and in dependence on the determined parameter of the high voltage traction bus controls the output means so that it is a outputs a control signal to cause a first switching means connected between the high voltage traction bus and a traction battery to electrically connect the high voltage traction bus to the traction battery.

Optionally, the high voltage traction bus parameter may be based on at least one of temperature, amount of precharge current, amount of time precharge current was applied to the high voltage traction bus, and voltage of the high voltage traction bus.

According to some embodiments, the parameter of the high-voltage traction bus may comprise the voltage of the high-voltage traction bus, and the processing device may be arranged to control the output device to output a control signal to cause a first switching device, which is between coupled to the high voltage traction bus and a traction battery, electrically coupling the high voltage traction bus to the traction battery in response to the voltage of the high voltage traction bus being greater than a threshold voltage.

According to some embodiments, the control system may further comprise parameter acquisition means arranged to monitor the parameter of the high voltage traction bus and to output the second signal indicative of the parameter of the high voltage traction bus.

According to some embodiments, the control system may be arranged to control the output means to output a control signal to cause a second switching device connected between a traction battery and the DCDC converter to electrically connect the DCDC converter the traction battery, the second switching device being connected in series with a resistive load, and
control the output means to output a control signal to close a third switching means connected in parallel with the second switching means and the resistive load between the traction battery and the DCDC converter.

In some embodiments, the control system may be configured such that, after the third switching device has closed, it controls the output device to output a control signal which causes the second switching device to open.

Optionally, the input means may be configured to receive a signal indicating that an onboard charger coupled to the DCDC converter is receiving AC power, and the processing means may be arranged to, in response to the signal indicating that an on-board charger receives alternating current, which controls the output means to output a control signal to cause the DCDC converter to convert a first voltage provided by the on-board charger to provide the pre-charge current.

According to some embodiments, the control system may be coupled to a traction battery including a first plurality of cells, a second plurality of cells, and a battery circuit operable in response to a control signal to selectively connect the first and second plurality of cells in series to switch to provide a first battery voltage at a battery output in a first mode, and to selectively connect the first and second plurality of cells in parallel to provide a second battery voltage at the battery output in a second mode, and the output means may be so arranged be that it provides the control signal to the battery circuit.

According to another aspect of the invention, there is provided a vehicle including the electric power circuit, the battery assembly, or the control system as described above.

According to another aspect of the invention, there is provided a method of controlling an electrical power circuit for a vehicle, the method comprising determining that power should be applied to a high voltage traction bus of the vehicle and in response to determining that power should be applied to the High-voltage traction bus is to be applied, causing electrical current to be applied to a DCDC converter, the DCDC converter being configured to provide a first voltage to a high-voltage auxiliary bus to provide a pre-charge current to the high-voltage traction bus to deliver.

According to another aspect of the invention, there is provided a method of controlling an electrical power circuit for a vehicle, the electrical power circuit including a high voltage traction bus for providing electrical power to one or more Trak traction motors and a DCDC converter arranged to receive a first voltage and provide a second voltage to a high voltage auxiliary power bus, the method comprising: determining that power is to be applied to the high voltage vehicle traction bus; and in response to determining that power is to be applied to the high voltage traction bus, causing the DCDC converter to provide the second voltage to the high voltage traction bus to provide a precharge current to the high voltage traction bus of the vehicle

According to some embodiments, the method may further include monitoring a parameter of the high voltage traction bus and connecting the high voltage traction bus to a traction battery depending on the monitored parameter.

Optionally, the parameter may be based on at least one of the following parameters: a temperature, a magnitude of the pre-charge current, a time value associated with the high-voltage traction bus, and a voltage of the high-voltage traction bus.

According to some embodiments, the high-voltage traction bus parameter may include a high-voltage traction bus voltage, and connecting the high-voltage traction bus to a traction battery depending on the monitored parameter may include connecting the high-voltage traction bus to a traction battery depending thereon that the voltage of the high voltage traction bus is greater than a threshold voltage.

According to some embodiments, after connecting the high voltage traction bus to the traction battery, the method may include controlling the DCDC converter to stop providing the pre-charge current.

Optionally, causing electrical power to be applied to the DCDC converter may include supplying electrical power from the traction battery.

Optionally, applying electrical power to the DCDC converter may include supplying electrical power from an external AC power supply via an onboard charger coupled to the DCDC converter.

According to a further aspect of the invention there is provided computer software which when executed by a computer is arranged to perform any method described herein. Optionally, the computer software is stored on a computer-readable medium. The computer software may be tangibly stored on a computer readable medium.

It is expressly intended within the scope of this application that the various aspects, embodiments, examples and alternatives set forth in the preceding paragraphs, in the claims and/or in the following description and drawings, and in particular the individual features thereof, independently or can be used in any combination. This means that all embodiments and/or features of an embodiment can be combined with one another in any way and/or combination, provided these features are not incompatible. Applicant reserves the right to amend any originally filed claim or to file a new claim accordingly, including the right to amend an originally filed claim to depend on another claim and/or to incorporate a feature of another claim, even if it was not originally claimed in this way.

character list

• In 1 ist ein Fahrzeug gemäß einer Ausführungsform der Erfindung dargestellt;
• 2 zeigt ein Beispiel für eine Traktionsbatterie, einen Fahrmotor und ein Steuersystem gemäß Ausführungsformen;
• 3 zeigt eine elektrische Stromschaltung, der mit einer Antriebsbatterie gemäß Ausführungsformen verbunden ist;
• 4A zeigt ein Beispiel für ein Steuersystem mit einem Steuergerät gemäß Ausführungsbeispielen;
• 4B zeigt ein Beispiel für ein nicht-übertragbares computerlesbares Medium, das Anweisungen gemäß Ausführungsformen speichert;
• 5 zeigt ein Beispiel für ein Verfahren gemäß den Ausführungsformen;
• 6 illustriert ein Beispiel für ein weiteres Verfahren gemäß Ausführungsformen.

One or more embodiments of the invention will now be described by way of example with reference to the accompanying figures, in which:

• In 1 a vehicle according to an embodiment of the invention is illustrated;
• 2 12 shows an example of a traction battery, traction motor, and control system according to embodiments;
• 3 12 shows an electric power circuit connected to a traction battery according to embodiments;
• 4A 12 shows an example of a control system with a controller according to embodiments;
• 4B Figure 12 shows an example of a non-transmittable computer-readable medium storing instructions according to embodiments;
• 5 Figure 12 shows an example of a method according to the embodiments;
• 6 12 illustrates an example of another method according to embodiments.

DETAILED DESCRIPTION

The examples disclosed herein may include a circuit and method for precharging a A high voltage electric vehicle traction bus without the use of a secondary switch and a resistive element in parallel with a primary switch to electrically connect the high voltage traction bus to a traction battery. In embodiments, a DCDC converter capable of providing a voltage to a high voltage auxiliary bus may be further connected to the high voltage traction bus and capable of providing a pre-charge current.

1 1 shows an example of a vehicle 10 in which embodiments of the invention may be implemented. In some, but not necessarily all, examples, the vehicle 10 is a passenger vehicle, also referred to as a car or an automobile. In other examples, embodiments of the invention may be used for other applications, such as industrial vehicles.

The vehicle 10 may be an electric vehicle (EV) or a hybrid electric vehicle (HEV). If the vehicle 10 is an HEV, the vehicle 10 may be a plug-in HEV or a mild HEV. If the vehicle 10 is a plug-in HEV, the vehicle 10 may be a series HEV or a parallel HEV. In a parallel HEV, a traction motor and an internal combustion engine can be operated in parallel to simultaneously generate tractive torque. In a serial HEV, the combustion engine generates electricity and the traction motor only provides the tractive torque.

2 1 shows an electric power system 200 with a traction battery 20 (hereafter “battery”), a DCDC converter 22, and a control system 26 for the EV or HEV 10, which may be supplied together or separately. In 2 A traction motor 28 that may optionally be part of the system 200 is also shown.

The battery 20 may be a high voltage battery, particularly when the vehicle 10 is an EV or a plug-in HEV. High-voltage traction batteries deliver nominal voltages in the hundreds of volts, in contrast to traction batteries for light HEVs, which deliver nominal voltages in the tens of volts. The battery 20 may have a voltage and capacity that allows for long-distance electric-only driving that requires continuous battery power.

The nominal voltage of the battery 20 can be in the range of several hundred volts. In some examples, the nominal voltage of the battery 20 is in the range of 250-1000 volts, more specifically between 270V and 470V or between 600V and 1000V. In certain examples, the voltage rating may be 400 volts or 800 volts to within a significant number. The nominal voltage is defined as the voltage between a positive terminal 25 of the battery and a negative terminal of the battery.

The battery 20 can have a capacity of several kilowatt hours to maximize range. The capacity can be in the range of tens of kilowatt hours or even over a hundred kilowatt hours.

The battery 20 includes a positive pole 25 and a negative pole. The terminals may be configured so that they can be connected to switching means to selectively connect the battery 20 to a high voltage traction bus 27, as illustrated by the switch 21 connected between the positive terminal 25 of the battery 20 and the high voltage traction bus 27 is switched. The high voltage traction bus 27 may be configured to provide power from the battery 20 to the traction motor 28 .

The battery 20 terminals are also configured for connection to the DCDC converter 22 . The DCDC converter 22 is configured to receive a DC voltage provided by the battery 20 and to provide one or more regulated DC voltage outputs, e.g. B. for a high voltage auxiliary bus 24.

The DCDC converter 22 also includes an output 23 which is connected to the high voltage traction bus 27 . The DCDC converter 22 is controllable to supply a pre-charge current to the high voltage traction bus 27 via the output 23 to equalize the voltage on the HV traction bus 27 before the switch 21 is closed to supply the HV traction bus 27 with the connect battery.

The control system 26 is operable to receive an indication that power is to be coupled to the HV traction bus 27, i. H. the HV traction bus 27 is to be connected to the battery 20 by closing the switch 21 . In response to receiving the indication that power is to be coupled to the HV traction bus 27, the control system 26 may cause a control message to be transmitted to the DCDC converter 22 to control the DCDC converter to provide the Pre-charging current at the output 23 provides. The precharge current can be provided by selectively coupling the output 23 to the high voltage auxiliary bus 24 .

The control system 26 is operable to monitor a parameter associated with the HV traction bus 27 and transmit a control sig nal to control the state of the switch 21 based on the monitored parameter. For example, the control circuit 26 may be configured to receive a signal indicative of a parameter value and control the state of the switch 21 based on the indication received.

The parameter monitored by the control system 26 may be a temperature, a voltage of the HV traction bus 27, a magnitude of the pre-charge current supplied to the HV traction bus 27 by the DCDC converter 22, and/or a time during which the HV traction bus 27 has been supplied with the pre-charge current by the DCDC converter 22 . For example, the control system 26 may compare a monitored HV traction bus 27 voltage to a threshold voltage and, in response to determining that the monitored voltage is greater than the threshold voltage, control the switch 21 to couple the battery to the HV traction bus 27 . In other embodiments, the control system 26 can monitor the magnitude of the pre-charge current provided by the DCDC converter 22, which can be expected to decrease as the HV traction bus 27 voltage increases, so that the control system 26 can determine when the HV traction bus has been charged to a sufficient voltage, or the control system 26 can control the DCDC converter 22 to apply the pre-charge voltage for a predetermined period of time before closing the switch 21 and connecting the HV traction bus 27 to the battery 20.

In some embodiments, the control system 26 may receive an indication of the HV traction bus 27 voltage and also an indication of the voltage provided by the traction battery 20 at the terminal 25 . Control system 26 may compare these voltages and provide a control message to close switch 21 when the voltages are determined to be within a threshold voltage.

Although only one battery 20 is shown, the vehicle 10 could include other traction batteries.

Although one traction motor 28 is shown, the vehicle 10 could include additional traction motors for the same or different vehicle 10 wheels.

In some examples, the DCDC converter 22 may be selectively connected to the battery 20 under control of the control system 26 . For example, a second switching means connected in series with a resistive load can be provided between the positive pole 25 of the battery 20 and the DCDC converter 22, and a third switching means connected in parallel with the second switching means and the resistive load. The second and third switching devices can be controlled by the control system 26 . When it is determined that the DCDC converter 22 should be powered, such as at the beginning of a drive cycle when a user desires to operate the vehicle 10, the control system 26 may provide a control signal that instructs the second switching device to close and the Connect DCDC converter 22 through the resistive load to the positive battery post 25 to precharge the DCDC converter circuit. Once it is determined that the DCDC converter circuit is sufficiently pre-charged, the control system 26 can provide a control signal that instructs the third switch to close and establish a direct connection for the provision of electrical energy between the terminal 25 and the DCDC converter 22 . Such a determination may be based on the lapse of a certain time or on a signal indicative of the voltage of the DCDC converter circuit.

The DCDC converter 22 can also include a charging circuit, such as. B. an on-board charger (OBC), for connecting a charging port (not shown) and / or a generator to the battery 20 include. The on-board charger may be configured to receive electrical power from an external source, such as a battery. an AC power supply, and provides a DC current that can be used to charge the battery 20 and also to power the DCDC converter 22 and any electrical buses or devices powered by the DCDC converter 22. In some examples, the control system 26 may anticipate that the HV traction bus 27 is to be powered and control the DCDC converter 22 to use the DC voltage provided by the on-board charger to supply the pre-charge current through the output 23 to the HV - traction bus 27 using electric power supplied from the external power source.

3 FIG. 3 shows an electrical circuit 300 connected to a traction battery 20 to form a battery assembly 350 for a vehicle according to the examples disclosed herein. The circuit 300 is referred to as a battery energy module (BEM) in this example. Within the BEM 300 is a Modular Electrical Electronic Architecture (MEEA) module 320, which includes a first high voltage DCDC converter 312a, a second DCDC converter 312b, and an OBC 316 in this example.

The circuit 300 includes a charging input 302 labeled "400V/800V HV DC Charger" for receiving electrical energy, which is connected to the DCDC converters 312a, 312b, to the OBC 316 and via the battery connection terminal 25 to the external battery pack 20. The connection from the charging input 302 to the battery pack 20 is used to supply electrical energy from the charging input 302 to charge the drive battery 20 .

The battery connector clip 25 electrically connects the traction battery 20 to the DCDC converters 312a, 312b and the OBC 316 and may receive electrical energy from the traction battery 20 to provide the second voltage to one or more traction motors 28 of the vehicle (in this example, the Output at 400V to a front HVDC traction motor and a rear HVDC traction motor 28 shown). For example, electric power may be supplied from the charging input 302 at 800V or 400V to charge the traction battery 20 and a traction motor 28 may be powered by the traction battery 20 at 400V. A DCDC converter 312a is configured to convert either 800V or 400V input voltage to 400V output voltage (although other high voltage outputs may be provided in various examples). Another DCDC converter 312b is configured to convert either 800V or 400V input voltage to 12V output voltage (although other low voltage outputs may be provided in various examples). Other examples may include one, three, or more than three DCDC converters.

The HV DCDC converter 312a is connected to an HV output 310a, labeled "400V 15kW Auxiliary Units" in this example (the output 310a itself includes two output channels, a first to an HV DC heater and a second to a HC DC cooler). The HV-DCDC converter 312a is also connected to the HV traction bus 27 via the output 23 in order to provide the pre-charging current for the HV traction bus 27 .

The NS-DCDC converter 312b is connected to a NS output 310b, labeled "4kW NS-DCDC" in this example. The outputs 312a, 312b are each connected to an electrical bus of the vehicle to supply electrical units of the vehicle with the specified output voltages (in this example two HV outputs 310a and one LV output 310b). The DCDC converters 312a, 312b are each configured to receive electrical energy from the charging input 302 and to supply electrical energy to the outputs 310a, 310b and 23 at the output voltage(s) while charging the traction battery 306 with the first voltage will. In this example, the first output 310a may provide an output voltage of 400V, which may be the same voltage (400V) as the voltage provided at the input 302 in some cases.

The DCDC converters 312a, 312b are also configured in this example to receive electrical energy from an AC charging input 314 (labeled "HV AC Charger") and convert the received AC power to supply battery terminal 25 electrical energy with the first Supply voltage for charging the traction battery 20. The onboard charger 316 is coupled to the DCDC converters 312a, 312b. Onboard charger 316 is configured to receive AC power at AC charge input terminal 314 and provide DC power to DCDC converters 312a, 312b. In this example, the OBC 316 is configured to accept 800V or 400V input voltage. In this example, the AC charging input 314 forms an external connection, e.g. B. for connection to an AC charging supply, and is connected to the OBC 316, which receives AC input power and provides DC power to the DCDC converters 312a, 312b. Also shown in this example are service checkpoints 324 configured to provide electrical access for port testing of the BEM.

The traction battery 20 in this example is electrically connected to the battery connection terminal 25 and enables the battery pack 20 to be connected to the power circuit 200. The traction battery 20 in this example comprises a first plurality of cells 322a, a second plurality of cells 322b and a battery control circuit (not shown) to selectively connect the first and second plurality of cells 322a, 322b in series to provide a first battery voltage at the battery output 25 in a first mode of operation, and to selectively connect the first and second plurality of cells 322a, 322b in parallel, to provide a second battery voltage at the battery output 25 in a second operating mode. In this example, the first and second plurality of cells 322a, 322b are each 400V cells, the first battery voltage may be 800V and the second battery voltage may be 400V.

4A illustrates how the control system 26 may be implemented. The control system 26 in 4A 10 shows a controller 30. In other examples, the control system 26 may include a variety of controllers onboard and/or external to the vehicle 10. FIG.

The control unit 30 of 4A comprises at least one electronic processor 32 and at least one electronic storage device 34 electrically connected to the electronic processor and storing instructions 36 (e.g., a computer program), the at least one electronic storage device 34 and the instructions 36 being so configured are that, in conjunction with the at least one electronic processor 32, they cause one or more of the methods described herein to be performed.

According to an example implementation, the controller 30 is of 4A a battery management system (BMS). The BMS can be located inside or outside of a protective battery 20 housing.

4B Figure 1 shows a non-transitory computer-readable storage medium 38 containing instructions 36 (computer software).

5 12 illustrates a method 500 for controlling an electrical power circuit for a vehicle 10 as disclosed herein, such as those in FIGS 2 and 3 illustrated electrical power circuits. The method 500 includes determining 502 that power is to be applied to a high voltage traction bus 27, causing 504 electrical power to be applied to a DCDC converter 22, and controlling the DCDC converter 22 to cause it to 506 to supply a pre-charge current to the high-voltage traction bus 27.

6 12 shows a method 600 for controlling an electrical power circuit for a vehicle 10 as disclosed herein, such as those in FIGS 2 and 3 illustrated electrical power circuits. The procedure 600 of 6 may be performed subsequent to the performance of method 500. The method 600 includes monitoring 602 a parameter associated with the HV traction bus 27, electrically connecting 604 the HV traction bus 27 to the traction battery 20 depending on the monitored parameter, and stopping the DCDC from supplying the pre-charge current to the HV traction bus 27 -Converter 22.

For purposes of this disclosure, it is to be understood that the controller(s) 30 described herein may each comprise a control unit or computing device having one or more electronic processors. A vehicle 10 and/or system thereof may include a single controller or electronic controller, or alternatively, various functions of the controller(s) may be embodied or housed in different controllers or controllers. A set of instructions could be provided that, when executed, cause the controller(s) or control unit(s) to implement the control techniques (including method(s)) described herein. The set of instructions may be embedded in one or more electronic processors, or alternatively the set of instructions could be provided as software to be executed by one or more electronic processors. For example, a first controller may be implemented in software running on one or more electronic processors, and one or more other controllers may also be implemented in software running on one or more electronic processors, optionally on the same or more processors as the first control unit. However, it should be understood that other arrangements are also useful, and as such, the present disclosure is not intended to be limited to any particular arrangement. In any event, the instruction set described above may be embedded in a computer-readable storage medium (e.g., a non-transitory computer-readable storage medium), which may include any mechanism for storing information in a form readable by a machine or electronic processor/computing device is, including but not limited to: a magnetic storage medium (e.g., floppy disk); optical storage medium (e.g. CD-ROM); magneto-optical storage medium; read only memory (ROM); random access memory (RAM); erasable programmable memory (e.g. EPROM and EEPROM); Flash memory; or electrical or other types of media for storing such information/instructions.

It will be apparent that various changes and modifications can be made in the present invention without departing from the scope of the present application.

The term "module" as used herein refers to a unit or device without specific parts/components that would be added by an end manufacturer or user.

As used in this application, "connected" means "electrically connected," either directly or indirectly. The electrical connection does not necessarily have to be galvanic. In relation to the control system, "connected" means that it is operably coupled to the extent that messages are sent and received through the appropriate means of communication.

The term "current" means electric current. The term "voltage" means a potential difference. The term "series" means electrical series. The term "parallel" means electrically parallel. The terms "active" and "operational" generally mean a closed circuit. The term "current" means electric current. The term "charging" means charging the battery electrically.

The in the 5 or 6 The blocks illustrated may represent steps in a method 500, 600 and/or portions of code in a computer program 36 configured to control electrical power circuitry as described above to perform the method steps. The depiction of a particular order of the blocks does not necessarily mean that there is a required or preferred order for the blocks, and the order and arrangement of the blocks may be varied. In addition, it is possible that some steps are omitted or added in other examples. Therefore, this disclosure also includes computer software configured when executed to perform any method disclosed herein, such as that described in FIGS 5 and 6 shown, performs. Optionally, the computer software 36 may be stored on a computer-readable medium and may also be stored tangibly.

Although embodiments of the present invention have been described in the preceding sections with reference to various examples, it should be noted that changes may be made to the examples provided without departing from the scope of the invention as claimed.

The features described in the preceding description can also be used in combinations other than those expressly described.

Although functions have been described with reference to particular features, those functions may be performed by other features, whether described or not.

Although features have been described with reference to particular embodiments, these features may be present in other embodiments as well, whether described or not.

Although the foregoing description has attempted to draw attention to those features of the invention which are deemed to be of particular importance, it is to be understood that applicant claims protection in respect of any patentable feature or combination of patentable features referred to herein referenced and/or depicted in the figures, whether or not particular emphasis is placed on them.

Claims (11)

Electrical power circuitry for a vehicle, comprising: a connector for electrical connection to a traction battery; a DCDC converter coupled to the port, the DCDC converter arranged to receive a first voltage and provide a second voltage to a high voltage auxiliary power bus; a high voltage traction bus for providing electrical power to one or more traction motors; and wherein the DCDC converter is coupled to the high voltage traction bus, the DCDC converter being arranged to provide the second voltage to the high voltage traction bus in response to an indication that power should be applied to the high voltage traction bus to provide a pre-charge current to the high-voltage traction bus. Electrical power circuit after claim 1 further comprises a first switching device connected between the terminal and the high voltage traction bus; and wherein the first switching means is arranged to electrically connect the terminal to the high voltage traction bus in response to a parameter associated with the high voltage traction bus. Electrical power circuit after claim 2 wherein the parameter comprises one of the following parameters: temperature, a magnitude of the pre-charge current, a time that the pre-charge current was supplied to the high-voltage traction bus, and a voltage of the high-voltage traction bus; optionally, the parameter associated with the high voltage traction bus includes the voltage of the high voltage traction bus; and wherein the first switching means is arranged to electrically connect the terminal to the high voltage traction bus in response to the voltage of the high voltage traction bus being greater than a threshold voltage. An electrical power circuit as claimed in any preceding claim, comprising: a second switching device connected in series with a resistive load, the second switching device and the resistive load being connected between the terminal and the DCDC converter; and a third switching device connected between the terminal and the DCDC converter in parallel with the second switching device and the resistive load. Electrical power circuitry according to any one of the preceding claims, comprising an on-board charger coupled to the DCDC converter, the on-board charger being arranged to receive AC power and supply the first voltage to the DCDC converter, the DCDC converter being so arranged is that it converts the first voltage provided by the on-board charger to provide the pre-charge current to the high-voltage traction bus. Electrical power circuit according to any of Claims 1 until 5 wherein the first voltage is provided by a traction battery coupled to the terminal and the DCDC converter is arranged to convert the first voltage provided by the traction battery to provide the pre-charge current for the high voltage traction bus. A battery assembly comprising a traction battery and the electrical power circuit of any preceding claim, wherein the traction battery is coupled to the terminal. A control system for controlling an electrical power circuit of a vehicle, the electrical power circuit comprising a high voltage traction bus for supplying electrical power to one or more traction motors and a DCDC converter arranged to receive a first voltage and a second voltage to a supplies high voltage auxiliary power bus, the control system comprising: input means for receiving a first signal indicative of power to be applied to a high voltage traction bus of the vehicle; outputting means for outputting a control signal for controlling the DCDC converter of the electric power circuit; and Processing means arranged in response to the first signal indicative of current to be applied to the high voltage traction bus to control the outputting means to output the control signal to cause the DCDC converter to operate the second to supply voltage to the high voltage traction bus to supply a pre-charge current to the vehicle's high voltage traction bus. Vehicle having the electrical power circuit according to any one of Claims 1 until 6 , according to the battery arrangement claim 7 or according to the tax system claim 8 . A method of controlling an electrical power circuit for a vehicle, the electrical power circuit comprising a high voltage traction bus for providing electrical power to one or more traction motors and a DCDC converter arranged to receive a first voltage and to apply a second voltage provides a high voltage auxiliary power bus, the method comprising: determining that power should be applied to the vehicle's high voltage traction bus; and in response to determining that current is to be applied to the high voltage traction bus, cause the DCDC converter to provide the second voltage to the high voltage traction bus to provide a pre-charge current to the vehicle's high voltage traction bus. Computer software which, when executed by a computer, is arranged to carry out a method claim 10 performs; optionally, the computer software is stored on a computer-readable medium.

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