Circuit and method for providing multimodal electrical energy to an electrical load in a vehicle

Abstract

Circuit for providing multimodal electrical energy to a load (52) in a vehicle, the circuit comprising: a first voltage source (54a) which has a positive side and a negative side; a second voltage source (54b) which has a positive side and a negative side; a positive main relay (56) having a first side and a second side, wherein the second side of the positive main relay (56) is connected to a first side of the load (52); a negative main relay (60) with a first side and a second side, wherein the second side of the negative main relay (60) is connected to a second side of the load (52); a first relay (62) that can be operated between an open position and a closed position, wherein the first relay (62) has a first side and a second side, wherein the first side of the first relay (62) is connected to the positive side of the first voltage source (54a) and the second side of the first relay (62) is connected to the negative side of the second voltage source (54b); a second relay (64) that is operable between an open position and a closed position, wherein the second relay (64) has a first side and a second side, the first side of the second relay (64) being connected to the positive side of the first voltage source (54a) and the second side of the second relay (64) being connected to the positive side of the second voltage source (54b) and the first side of the positive main relay (56); and a third relay (66) that can be operated between an open position and a closed position, wherein the third relay (66) has a first side and a second side, wherein the first side of the third relay (66) is connected to the negative side of the second voltage source (54b) and the second side of the third relay (66) is connected to the first side of the negative main relay (60).

Description

TECHNICAL FIELD

[0001] The following relates to a circuit and method for providing multimodal electrical power to an electrical load in a vehicle. BACKGROUND

[0002] A high-voltage architecture topology for an electric vehicle may include two circuits, each containing an HV voltage source (e.g., 400 volts), a positive main relay connecting a positive side of the HV voltage source to an electrical load (e.g., a DC link capacitor), a negative main relay connecting a negative side of the HV voltage source to the electrical load, and a precharge relay connected in parallel with the positive main relay. Such a topology may also include a relay connecting the positive side of one HV voltage source to the negative side of the other HV voltage source.

[0003] In such a topology, the electrical load can be connected individually to one or the other high-voltage source, to both in series, or to both in parallel by providing different configurations of open or closed states for the various relays. However, duplicating the circuits in such a topology increases the cost as well as the number of potential failure points (e.g., a "stuck open" (i.e., welded) or "stuck closed" relay) associated with it. Such a topology also requires a complex relay control sequence to detect the status of the relays and to provide single, series, or parallel connection of the high-voltage source(s) with the vehicle's electrical load.

[0004] DE 10 2021 118 869 A1 relates to an on-board electrical system for a motor vehicle, comprising a vehicle battery having at least two partial batteries and at least one conventional supply connection electrically coupled to the vehicle battery in such a way that the vehicle battery provides electrical energy from more than one of the at least two partial batteries to at least one conventional supply connection.

[0005] DE 10 2018 218 312 A1 shows a power supply arrangement for supplying at least one electrical consumer of a low-voltage electrical system of a motor vehicle.

[0006] From DE 10 2017 208 030 B4, an on-board power supply for a motor vehicle with a circuit arrangement for providing a redundant power supply to at least one safety consumer is known.

[0007] DE 10 2016 015 311 A1 teaches an electric drive system for a vehicle and a method for its operation.

[0008] DE 103 61 743 A1 specifies a device for switching a battery in a dual-voltage vehicle electrical system in a vehicle, which can be given external starting assistance by supplying an auxiliary voltage, even if the auxiliary voltage does not correspond to the voltage of the starter circuit.

[0009] DE 100 55 531 A1 relates to an electronic circuit arrangement for supplying voltage to consumers in a motor vehicle, its use for supplying voltage to an electromechanical or electrohydraulic braking system or an electromechanical steering system for motor vehicles, and a method for operating the circuit arrangement. TECHNICAL TASK AND SOLUTION OF THE INVENTION

[0010] The technical problem to be solved is to provide a circuit and an improved method for providing multimodal electrical energy to an electrical load in a vehicle that are improved compared to the prior art. This problem is solved by a circuit for providing multimodal electrical energy to a load in a vehicle with the features of patent claim 1, a method for providing multimodal electrical energy to a load in a vehicle with the features of patent claim 9, and / or a non-transitory computer-readable storage medium with stored computer-executable instructions for providing multimodal electrical energy to a load in a vehicle with the features of patent claim 15.

[0011] Such an improved circuit and method provide a high-voltage architecture topology for an electric vehicle that reduces the number of required components, thereby reducing both the cost and the number of potential failure points associated with it. Such an improved circuit and method also provide a simplified and / or improved relay control sequence for detecting the status of relays and providing multiple current types to an electrical load in a vehicle.

[0012] According to a non-limiting exemplary embodiment described herein, a circuit is provided for providing multi-modal electrical power to a load in a vehicle. The circuit includes a first voltage source having a positive side and a negative side, a second voltage source having a positive side and a negative side, a positive main relay having a first side and a second side, the second side of the positive main relay being connected to a first side of the load, and a negative main relay having a first side and a second side, the second side of the negative main relay being connected to a second side of the load.The circuit further comprises a first relay operable between an open position and a closed position, the first relay having a first side and a second side, the first side of the first relay being connected to the positive side of the first voltage source and the second side of the first relay being connected to the negative side of the second voltage source. The circuit further comprises a second relay operable between an open position and a closed position, the second relay having a first side and a second side, the first side of the second relay being connected to the positive side of the first voltage source and the second side of the second relay being connected to the positive side of the second voltage source and the first side of the positive main relay.The circuit further comprises a third relay operable between an open position and a closed position, the third relay having a first side and a second side, the first side of the third relay being connected to the negative side of the second voltage source and the second side of the third relay being connected to the first side of the negative main relay.

[0013] According to another non-limiting exemplary embodiment described herein, a method is provided for providing multi-modal electrical power to a load in a vehicle, the vehicle having a first voltage source and a second voltage source, the load having a first side and a second side, the first voltage source having a positive side and a negative side, and the second voltage source having a positive side and a negative side. The method includes connecting a positive main relay having a first side and a second side to the load by connecting the second side of the positive main relay to the first side of the load, and connecting a negative main relay having a first side and a second side to the load by connecting the second side of the negative main relay to the second side of the load.The method further comprises connecting a first relay having a first side and a second side to the first voltage source and the second voltage source by connecting the first side of the first relay to the positive side of the first voltage source and connecting the second side of the first relay to the negative side of the second voltage source. The method further comprises connecting a second relay having a first side and a second side to the first voltage source, the second voltage source, and the positive main relay by connecting the first side of the second relay to the positive side of the first voltage source and connecting the second side of the second relay to the positive side of the second voltage source and the first side of the positive main relay.The method further comprises connecting a third relay having a first side and a second side to the second voltage source and the negative main relay by connecting the first side of the third relay to the negative side of the second voltage source and connecting the second side of the third relay to the first side of the negative main relay, wherein each of the first, second, and third relays is independently operable between an open position and a closed position. The method further comprises supplying electrical power from at least one of the first voltage source and the second voltage source to provide the vehicle's electrical load according to one of a plurality of operating modes by opening or closing each of the first, second, and third relays.

[0014] According to another non-limiting exemplary embodiment described herein, a non-transitory computer-readable storage medium having stored computer-executable instructions for providing multimodal electrical power to a load in a vehicle, the vehicle comprising (i) a first voltage source having a positive side and a negative side, (ii) a second voltage source having a positive side and a negative side, (iii) a positive main relay having a first side and a second side, the second side of the positive main relay being connected to a first side of the load, (iv) a negative main relay having a first side and a second side, the second side of the negative main relay being connected to a second side of the load, (v) a first relay,which is operable between an open position and a closed position, wherein the first relay has a first side and a second side, wherein the first side of the first relay is connected to the positive side of the first voltage source, and the second side of the first relay is connected to the negative side of the second voltage source, (vi) a second relay operable between an open position and a closed position, wherein the second relay has a first side and a second side, wherein the first side of the second relay is connected to the positive side of the first voltage source, and the second side of the second relay is connected to the positive side of the second voltage source and the first side of the positive main relay, (vii) a third relay operable between an open position and a closed position, wherein the third relay has a first side and a second side,the first side of the third relay is connected to the negative side of the second voltage source, and the second side of the third relay is connected to the first side of the negative main relay; and (viii) a controller configured to independently control the operation of the first, second, and third relays between the open and closed positions. The computer-executable instructions are configured to cause the controller to provide electrical load from the first voltage source and / or the second voltage source according to one of a plurality of operating modes based on the open or closed positions of the first, second, and third relays.

[0015] A detailed description of these and other non-limiting exemplary embodiments of a circuit and method for providing multi-modal electrical power to an electrical load in a vehicle is set forth below together with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1A is a simplified schematic diagram of a known topology for a high-voltage architecture for providing electrical power to an electrical load in a vehicle; Fig. 1B is an exemplary simplified schematic diagram of an exemplary embodiment of a topology for a high voltage architecture for providing electrical power to an electrical load in a vehicle according to the present disclosure; The Fig. 2A-2D are exemplary simplified schematic diagrams showing exemplary control of the Fig. 1B illustrate the exemplary embodiment of a topology for a high voltage architecture for providing electrical power to an electrical load in a vehicle according to the present disclosure; Fig. 3A is an exemplary flowchart illustrating an exemplary embodiment of a control sequence for the relays as described in Fig. 2A shows the exemplary embodiment of a topology for a high voltage architecture for providing electrical power to an electrical load in a vehicle according to the present disclosure; Fig. 3B is an exemplary flowchart illustrating an exemplary embodiment of a control sequence for the relays as described in the Fig. 2B and Fig. 2D of the exemplary embodiment of a topology for a high-voltage architecture for providing electrical power to an electrical load in a vehicle according to the present disclosure; and Fig. 3C is an exemplary flowchart illustrating an exemplary embodiment of a control sequence for the relays as described in the Fig. 2C and Fig. 2D of the exemplary embodiment of a topology for a high voltage architecture for providing electrical power to an electrical load in a vehicle according to the present disclosure. DETAILED DESCRIPTION

[0016] As required, detailed, non-limiting embodiments are disclosed herein. However, it is to be understood that the disclosed embodiments are merely exemplary and may take various and alternative forms. The figures are not necessarily to scale, and features may be exaggerated or reduced to show details of particular components. Therefore, the specific structural and functional details disclosed herein are not to be considered limiting, but merely as a representative basis for teaching one skilled in the art.

[0017] With reference to the figures, a more detailed description of non-limiting exemplary embodiments of a circuit and method for providing multimodal electrical power to an electrical load in a vehicle is provided. For ease of illustration and understanding, like reference numerals may be used for like components and features throughout the drawings.

[0018] Fig. 1A is a simplified schematic diagram of a known topology 10 for a high-voltage (HV) architecture for providing electrical power to an electrical load 18 in a vehicle. As seen therein, the topology 10 may include two circuits, each including an HV voltage source (e.g., 400 volts), 14a and 14b, each of which may have an associated current-voltage sensor (CVS), 15a and 15b. Each circuit in the topology 10 may also include a positive main relay 16a (Relay B) and 16b (Relay E) connecting a positive side of its respective voltage source 14a and 14b to an electrical load 18, e.g., a DC link capacitor. Each circuit may also include a negative main relay 20a (Relay D) and 20b (Relay G) connecting a negative side of its respective voltage source 14a and 14b to the electrical load 18.Each circuit may also include a precharge relay 22a (Relay C) and 22b (Relay F) connected in parallel with its respective positive main relay 16a (Relay B) and 16b (Relay E). Such a topology may also include a relay 24 connecting the positive side of voltage source 14b to the negative side of voltage source 14a.

[0019] In such a topology 10, the electrical load 18 can be connected to the voltage source 14a or 14b individually, or to both the voltage source 14a and the voltage source 14b connected in series, or to the voltage source 14a and the voltage source 14b connected in parallel by providing various configurations of open or closed states for the various relays 16a, 16b, 20a, 20b, 22a, 22b, 24. As is known to those skilled in the art, each of the relays 16a, 16b, 20a, 20b, 22a, 22b, 24 can be switched between an open position and a closed position.It should also be noted that a controller (not shown) may be provided in communication with the relays 16a, 16b, 20a, 20b, 22a, 22b, 24 and configured to provide one or more control signals for operating or actuating each of the relays 16a, 16b, 20a, 20b, 22a, 22b, 24 between or to its respective open or closed position or state.

[0020] More precisely, still referring to Fig. 1A, when relays 16a (relay B) and 20a (relay D) are closed and relays 24 (relay A), 16b (relay E), 22b (relay F), and 20b (relay G) are opened, only voltage source 14a is connected to electrical load 18. Likewise, when relays 16b (relay E) and 20b (relay G) are closed and relays 24 (relay A), 16a (relay B), 22a (relay C), and 20a (relay D) are opened, only voltage source 14b is connected to electrical load 18. In addition, when relays 16a (relay B), 20a (relay D), 16b (relay E), and 20b (relay G) are closed and relay 24 (relay A) is opened, voltage source 14a and voltage source 14b are connected in parallel to electrical load 18. In addition, when relays 24 (relay A), 16a (relay B), and 20b (relay G) are closed and relays 20a (relay D), 16b (relay E), and 22b (relay F) are opened, voltage source 14a and voltage source 14b are connected in series to electrical load 18.

[0021] However, the duplication of circuits in topology 10 increases the cost as well as the number of potential failure points (e.g., a "stuck open" (i.e., welded) or a "stuck closed" relay (16a, 16b, 20a, 20b, 22a, 22b, 24)) associated with it. Topology 10 also requires a complex relay control sequence to detect the state of relays 16a, 16b, 20a, 20b, 22a, 22b, 24 and to provide single, series, or parallel connection of voltage source 14a and voltage source 14b to the vehicle's electrical load 18.

[0022] Consequently, there is a need for an improved circuit and method for providing multimodal electrical power to an electrical load in a vehicle. Such an improved circuit and method would provide a high-voltage architecture topology for an electric vehicle that would reduce the number of required components, thereby reducing both the cost and the number of potential failure points associated with it. Such an improved circuit and method would also provide a simplified and / or improved relay control sequence for detecting the status of relays and providing multiple power types to an electrical load in the vehicle.

[0023] In this regard, Fig. 1B is an exemplary, simplified schematic diagram of an exemplary embodiment of a topology 50 for a high-voltage architecture for providing electrical power to an electrical load 52 in a vehicle according to the present disclosure. As seen therein, the topology 50 may include a circuit for providing multi-modal electrical power to a load 52 in a vehicle, such as a DC link capacitor. The circuit may include a first voltage source 54a having a positive side and a negative side, and a second voltage source 54b having a positive side and a negative side. The circuit may further include a positive main relay 56 (Relay B) having a first side and a second side. The second side of the positive main relay 56 (Relay B) may be connected to a first side of the load 52.The circuit may further include a negative main relay 60 (Relay F) having a first and a second side. The second side of the negative main relay 60 (Relay F) may be connected to a second side of the load 52.

[0024] The circuit may also include a first relay 62 (Relay A) having a first side and a second side. The first side of the first relay 62 (Relay A) may be connected to the positive side of the first voltage source 54a, and the second side of the first relay 62 (Relay A) may be connected to the negative side of the second voltage source 54b. The circuit may further include a second relay 64 (Relay E) having a first side and a second side. The first side of the second relay 64 (Relay E) may be connected to the positive side of the first voltage source 54a, and the second side of the second relay 64 (Relay E) may be connected to the positive side of the second voltage source 54b and the first side of the positive main relay 56 (Relay B). The circuit may further include a third relay 66 (Relay D) having a first side and a second side.The first side of the third relay 66 (Relay D) may be connected to the negative side of the second voltage source 54b, and the second side of the third relay 66 (Relay D) may be connected to the first side of the negative main relay 60 (Relay F). The circuit may also include a precharge relay 68 (Relay C), which may be connected in parallel with the positive main relay 56 (Relay B).

[0025] Electrical energy may be provided by the first voltage source 54a and / or the second voltage source 54b according to one of a variety of operating modes based on the open or closed positions of the first relay 62 (Relay A), the second relay 64 (Relay E), and the third relay 66 (Relay D). As is known to those skilled in the art, each of the relays 56, 60, 62, 64, 66, 68 may be switched back and forth between an open position and a closed position. In this context, it is noted that in Fig. 1B all relays 56, 60, 62, 64, 66, 68 are shown in their respective open positions.

[0026] It should also be noted that a controller 70 may be provided via signal lines 56S, 60S, 62S, 64S, 66S, 68S in communication with the relays 56, 60, 62, 64S, 66S, 68S. The controller 70 may also be configured to generate one or more control signals and transmit such control signals via the signal lines 56S, 60S, 62S, 64S, 66S, 68S to the relays 56, 60, 62, 64, 66, 68 to operate or switch each of the relays 56, 60, 62, 64, 66, 68 between or to its respective open or closed position or state. In this regard, the relays 56, 60, 62, 64, 66, 68 may be independently controlled between or into their respective open and closed positions, and the controller 70 may be configured to independently control the operation of the relays 56, 60, 62, 64, 66, 68 between or into their respective open and closed positions.

[0027] As will be understood by those skilled in the art, the controller 70, as well as any other controller, control unit, communication unit, system, subsystem, unit, module, interface, sensor, device, relay, switch, component, or the like described herein, may individually, collectively, or in any combination, include suitable circuitry, such as one or more suitably programmed processors (e.g., one or more microprocessors, including central processing units (CPUs)) and associated memory, storage media, or storage devices, which may include stored operating system software and / or application software executable by the processor(s) to control the operation and carry out the particular algorithm(s) represented by the various methods, functions, and / or operations described herein, including interaction between and / or cooperation with one another.One or more such processors, as well as other circuits and / or hardware, may be included in a single application-specific integrated circuit (ASIC), or multiple processors and various circuits and / or hardware may be distributed among multiple separate components, either individually packaged or arranged into a system-on-a-chip (SoC). The controller 70, as well as any other controller, control unit, communication unit, system, subsystem, unit, module, interface, sensor, device, relay, switch, component, or the like described herein, may therefore include one or more processors and an associated memory, storage medium, or storage device storing computer-executable instructions for performing the particular algorithm(s) represented by the various methods, functions, and / or operations described herein.In this regard, it should be understood that the computer-executable instructions described herein may be stored in or on a computer-readable storage medium, which may include any known type of storage medium or device, and may be part of or connected to the controller 70.

[0028] The Fig. 2A-2D are exemplary, simplified schematic representations showing the exemplary control of the Fig. 1B of the exemplary embodiment of a topology 50 for a high-voltage architecture for providing electrical power to an electrical load 52 in a vehicle according to the present disclosure. While the controller 70 and the signal lines 56S, 60S, 62S, 64S, 66S, 68S shown in Fig. 1B, in each of the Fig. 2A-2D have been omitted, it is pointed out in this context that the relays 56, 60, 62, 64, 66, 68, which are used in the Fig. 2A-2D, are nevertheless controlled by the controller 70 via the signal lines 56S, 60S, 62S, 64S, 66S, 68S, which are shown in the Fig. 2A-2D have been omitted to simplify these figures and to facilitate illustration.

[0029] With reference first to Fig. 2A and with continued reference to Fig. 1B, in one operating mode, the controller 70 may control the relays 56, 60, 62, 64, 66, 68 such that the first relay 62 may be closed, the second relay 64 may be opened, and the third relay 66 may be opened, thereby connecting the first and second voltage sources 54a, 54b to the load 52, wherein the first and second voltage sources 54a, 54b are connected in series. In this context, a first current flows along the path designated I1 when the controller 70 controls the positive main relay 56 (and / or the precharge relay 68) and the negative main relay 60 to closed positions. In this way, where each voltage source 54a, 54b is a 400-volt high-voltage battery or battery pack, an 800-volt compatible high-voltage architecture is provided, with a total of 800 volts being provided by the voltage sources 54a and 54b to the load 52. It is noted that the pre-charge relay 68 in Fig. 2A is shown in an open position after being controlled to such a position by the controller 70, having previously been controlled by the controller 70 (along with the negative main relay 60) to a closed position to precharge the DC link capacitor 52. After such precharging of the DC link capacitor 52, the controller 70 can then control the positive main relay 56 to its closed position and then control the precharge relay 68 to its open position.

[0030] According to Fig. 2B and with continued reference to Fig. 1B, in another operating mode, the controller 70 can control the relays 56, 60, 62, 64, 66, 68 such that the first relay 62 can be opened, the second relay 64 can be opened, and the third relay 66 can be closed, thereby connecting only the second voltage source 54b to the load 52. In this regard, a second current flows along the path designated I2 when the controller 70 controls the positive main relay 56 (and / or the pre-charge relay 68) as well as the negative main relay 60 to closed positions. In this way, if each voltage source 54a, 54b is a 400-volt high-voltage battery or battery pack, a total of 400 volts is provided from the voltage source 54b to supply the load 52. It should be noted that the pre-charge relay 68 in Fig. 2B is shown in an open position after being controlled to such a position by the controller 70, having previously been controlled by the controller 70 (along with the negative main relay 60) to its closed position to precharge the DC link capacitor 52. After such precharging of the DC link capacitor 52, the controller 70 can then control the positive main relay 56 to its closed position and then control the precharge relay 68 to its open position.

[0031] With reference to Fig. 2C and with continued reference to Fig. 1B, in another operating mode, the controller 70 may control the relays 56, 60, 62, 64, 66, 68 such that the first relay 62 is opened, the second relay 64 is closed, and the third relay 66 is opened, thereby connecting only the first voltage source 54a to the load 52. In this regard, a third current flows along the path designated I3 when the controller 70 controls the positive main relay 56 (and / or the pre-charge relay 68) as well as the negative main relay 60 to closed positions. In this way, when each voltage source 54a, 54b is a 400-volt high-voltage battery or battery pack, a 400-volt compatible high-voltage architecture is provided, with a total voltage of 400 volts provided by the voltage source 54a. It should be noted that the pre-charge relay 68 in Fig. 2C is shown in an open position after being controlled to such a position by the controller 70, having previously been controlled by the controller 70 (along with the negative main relay 60) to its closed position to precharge the DC link capacitor 52. After such precharging of the DC link capacitor 52, the controller 70 may then control the positive main relay 56 to its closed position and then control the precharge relay 68 to its open position.

[0032] With reference to Fig. 2D and with continued reference to Fig. 1B, in another operating mode, the controller 70 may control the relays 56, 60, 62, 64, 66, 68 such that the first relay 62 may be opened, the second relay 64 may be closed, and the third relay 66 may be closed, thereby connecting the first and second voltage sources 54a, 54b to the load 52, the first and second voltage sources 54a, 54b being connected in parallel. In this regard, the second and third currents I2 and I3 flow along the illustrated paths when the controller 70 controls the positive main relay 56 (and / or the precharge relay 68) and the negative main relay 60 to closed positions. In this way, with each voltage source 54a, 54b being a 400-volt high-voltage battery or battery pack, a 400-volt compatible high-voltage architecture is provided, with a total voltage of 400 volts being provided by the voltage sources 54a and 54b to the load 52.It should be noted that the precharge relay 68 in . Fig. 2D is shown in an open position after being controlled to such a position by the controller 70, having previously been controlled by the controller 70 (along with the negative main relay 60) to its closed position to precharge the DC link capacitor 52. After such precharging of the DC link capacitor 52, the controller 70 can then control the positive main relay 56 to its closed position and then control the precharge relay 68 to its open position.

[0033] Fig. 3A is an exemplary flowchart illustrating an exemplary embodiment of a control sequence 100 for the relays 56, 60, 62, 64, 66, 68 as shown in Fig. 2A of the exemplary embodiment of a topology 50 for a high-voltage architecture for providing electrical power to an electrical load 52 in a vehicle according to the present disclosure. As described therein and with further reference to Fig. 1B and Fig. 2A, after startup 102, the controller 70 may perform a status check 104 of the relays 56, 60, 62, 64, 66, 68 to determine 106 whether one or more of the relays 56, 60, 62, 64, 66, 68 are welded (i.e., "tightly closed"). If so, the controller 70 may control the circuit and / or method to transition to a high voltage supply OFF state 108 such that no electrical power is provided to the load 52. If not, the controller 70 may generate a control signal to control the precharge relay 68 (Relay C) to a closed position 110 and then check 112 whether the status of the precharge relay 68 (Relay C) is "open." If so, the controller 70 may control the circuit and / or method to transition to the high voltage off state 108.

[0034] Otherwise, if the precharge relay status is not "jammed open," the controller 70 may generate a control signal to control the first relay 62 (Relay A) to a closed position 114 and then check 116 whether the first relay 62 (Relay A) status is "jammed open." If so, the controller 70 may control the circuit and / or method to transition to the "high voltage off" state 108. If not, the controller 70 may generate a control signal to control the negative main relay 60 (Relay F) to a closed position 120 and then check 116 whether the negative main relay 60 (Relay F) status is "jammed open." If this is the case, the controller 70 may control the circuit and / or method to enter the high voltage off state 108.If not, a precharge operation 124 may begin, and the controller 70 may then determine 126 whether a precharge timeout has occurred, that is, whether a selected period of time has elapsed before a successful precharge of the DC link capacitor 52 has been performed. If so, the controller 70 may control the circuit and / or method to transition to the high voltage off state 108.

[0035] Alternatively, if the controller 126 determines that a precharge timeout has not occurred, the controller may include a control signal to control the positive main relay 56 (Relay B) to a closed position 128 and a control signal to control the precharge relay 68 (Relay C) to an open position 130. The controller 70 may then check 132 whether the status of the positive main relay 56 (Relay B) is "stuck open." If so, the controller 70 may input and / or control the circuit and / or method to enter the "high voltage off" state 108. Otherwise, the controller 70 may input and / or control the circuit and / or method to enter an on state of the high voltage 134 such that both the first and second voltage sources 54a, 54b are connected to and provide electrical energy to the load 52, the first and second voltage sources 54a, 54b being connected in series.

[0036] Fig. 3B is an exemplary flowchart illustrating an exemplary embodiment of a control sequence 200 for the relays 56, 60, 62, 64, 66, 68 as shown in the Fig. 2B and Fig. 2D of the exemplary embodiment of a topology 50 for a high-voltage architecture for providing electrical power to an electrical load 52 in a vehicle according to the present disclosure. As described therein and with continued reference to the Fig. 1B, Fig. 2B and Fig. 2D, after startup 202, the controller 70 may perform a status check 204 of the relays 56, 60, 62, 64, 66, 68 to determine 206 whether one or more of the relays 56, 60, 62, 64, 66, 68 are welded (i.e., "tightly closed"). If so, the controller 70 may control the circuit and / or method to transition to a high voltage off state 208 such that no electrical power is provided to the load 52. If not, the controller 70 may generate a control signal to control the precharge relay 68 (Relay C) to a closed position 210 and then check 212 whether the status of the precharge relay 68 (Relay C) is "stuck open." If so, the controller 70 may control the circuit and / or method to transition to the high voltage off state 208.

[0037] Otherwise, if the precharge relay status is not "jammed open," the controller 70 may generate a control signal to control the third relay 66 (Relay D) to a closed position 214 and then check 216 whether the third relay 66 (Relay D) status is "jammed open." If so, the controller 70 may control the circuit and / or method to transition to the high voltage off state 208. If not, the controller 70 may generate a control signal to control the negative main relay 60 (Relay F) to a closed position 218 and then check 220 whether the negative main relay 60 (Relay F) status is "jammed open." If so, the controller 70 may control the circuit and / or method to transition to the high voltage off state 208.If not, a precharge operation 222 may begin, and the controller 70 may then determine 224 whether a precharge timeout has occurred, i.e., whether a selected period of time has elapsed before a successful precharge of the DC link capacitor 52 has been performed. If so, the controller 70 may control the circuit and / or method to transition to the high voltage off state 208.

[0038] Alternatively, if the controller 70 determines 224 that a precharge timeout has not occurred, it may generate a control signal to control the positive main relay 56 (Relay B) to a closed position 226 and a control signal to control the precharge relay 68 (Relay C) to an open position 228. The controller 70 may then check 230 whether the status of the positive main relay 56 (Relay B) is "stuck open." If so, the controller 70 may control the circuit and / or method to transition to the high voltage off state 208. If not, the controller 70 may determine whether a parallel connection of the first and second voltage sources 54a, 54b with the load 52 should be satisfied.If this is not the case, the controller 70 may control the circuit and / or method to enter a high voltage ON state 234 such that only the second voltage source 54b is connected to the load 52 and provides it with electrical energy (see . Fig. 2B).

[0039] Otherwise, if the controller 70 determines 232 that a parallel connection of the first and second voltage sources 54a, 54b with the load 52 should be satisfied, the controller 70 may generate a control signal to control the second relay 64 (Relay E) to a closed position 236. The controller 70 may then check 240 whether the status of the second relay 64 (Relay E) is "stuck open." If so, the controller 70 may control the circuit and / or method to transition to the high voltage off state 208. If this is not the case, the controller 70 can input and / or control the circuit and / or method to change to the high voltage ON state 234, so that both the first and second voltage sources 54a, 54b are connected to the load 52 and provide it with electrical energy, wherein the first and second voltage sources 54a, 54b are connected in parallel (see Fig. 2D).

[0040] Fig. 3C is an exemplary flowchart illustrating an exemplary embodiment of a control sequence 300 for relays 56, 60, 62, 64, 66, 68 as shown in the Fig. 2C and Fig. 2D of the exemplary embodiment of a topology 50 for a high-voltage architecture for providing electrical power to an electrical load 52 in a vehicle according to the present disclosure. As described therein and with continued reference to the Fig. 1B, Fig. 2C and Fig. 2D, after startup 302, the controller 70 may perform a condition check 304 of the relays 56, 60, 62, 64, 66, 68 to determine 306 whether one or more of the relays 56, 60, 62, 64, 66, 68 are welded (i.e., "jammed closed"). If so, the controller 70 may control the circuit and / or method to transition to a high voltage off state 308 such that no electrical power is provided to the load 52. If not, the controller 70 may generate a control signal to control the precharge relay 68 (Relay C) to a closed position 310 and then check 312 whether the condition of the precharge relay 68 (Relay C) is "jammed open." If so, the controller 70 may control the circuit and / or method to transition to the high voltage off state 308.

[0041] Otherwise, if the status of the precharge relay 68 (Relay C) is not "jammed open," the controller 70 may generate a control signal to control the second relay 64 (Relay E) to a closed position 314 and then check 316 whether the status of the third relay 64 (Relay E) is "jammed open." If so, the controller 70 may control the circuit and / or method to transition to the high voltage off state 308. If not, the controller 70 may generate a control signal to control the negative main relay 60 (Relay F) to a closed position 318 and then check 320 whether the status of the negative main relay 60 (Relay F) is "jammed open." If so, the controller 70 may control the circuit and / or method to transition to the high voltage off state 308.If not, a precharge operation 322 may begin, and the controller 70 may then determine 324 whether a precharge timeout has occurred, that is, whether a selected period of time has elapsed before a successful precharge of the DC link capacitor 52 has been performed. If so, the controller 70 may control the circuit and / or method to transition to the high voltage off state 308.

[0042] Alternatively, if the controller 70 determines (324) that no precharge timeout has occurred, the controller 70 may generate a control signal to control the positive main relay 56 (Relay B) to a closed position (326) and a control signal to control the precharge relay 68 (Relay C) to an open position (328). The controller 70 may then check 330 whether the status of the positive main relay 56 (Relay B) is "stuck open." If so, the controller 70 may control the circuit and / or method to transition to the high voltage off state 308. If not, the controller 70 may then determine 332 whether a parallel connection of the first and second voltage sources 54a, 54b with the load 52 should be satisfied.If this is not the case, the controller 70 can control the circuit and / or the method such that it goes into an on state 334 of the high voltage, so that only the first voltage source 54a is connected to the load 52 and provides it with electrical energy (see . Fig. 2C).

[0043] Otherwise, if the controller 70 determines 332 that a parallel connection of the first and second voltage sources 54a, 54b with the load 52 should be satisfied, the controller 70 may generate a control signal to control the third relay 66 (Relay D) to a closed position 336. The controller 70 may then check 338 whether the status of the third relay 66 (Relay D) is "stuck open." If so, the controller 70 may control the circuit and / or method to transition to the high voltage off state 308. If this is not the case, the controller 70 can input and / or control the circuit and / or method to change to the high voltage ON state 334, so that both the first and second voltage sources 54a, 54b are connected to the load 52 and provide it with electrical energy, wherein the first and second voltage sources 54a, 54b are connected in parallel (see Fig. 2D).

[0044] With reference to the Fig. 1A-1B, 2A-2D, and 3A-3C, the present disclosure describes a circuit for providing multi-modal electrical power to a load 52 in a vehicle. The circuit may include a first voltage source 54a having a positive side and a negative side, and a second voltage source 54b having a positive side and a negative side. The circuit may further include a positive main relay 56 having a first side and a second side, wherein the second side of the positive main relay 56 is connectable to a first side of the load 52. The circuit may also include a negative main relay 60 having a first side and a second side, wherein the second side of the negative main relay 60 is connectable to a second side of the load 52.

[0045] The circuit may further include a first relay 62 operable between an open position and a closed position, the first relay 62 having a first side and a second side, the first side of the first relay 62 being connected to the positive side of the first voltage source 54a, and the second side of the first relay 62 being connected to the negative side of the second voltage source 54b. The circuit may also include a second relay 64 operable between an open position and a closed position, the second relay 64 having a first side and a second side, the first side of the second relay 64 being connected to the positive side of the first voltage source 54a, and the second side of the second relay 64 being connected to the positive side of the second voltage source 54b and the first side of the positive main relay 56.The circuit may further include a third relay 66 operable between an open position and a closed position, the third relay 66 having a first side and a second side, the first side of the third relay 66 being connected to the negative side of the second voltage source 54b, and the second side of the third relay 66 being connected to the first side of the negative main relay 60. Accordingly, electrical power from the first voltage source 54a and / or the second voltage source 54b may be provided to the load 52 according to one of a variety of operating modes based on the open or closed positions of the first relay 62, the second relay 64, and the third relay 66.

[0046] In this regard, in a first operating mode, the first relay 62 may be closed, the second relay 64 may be open, and the third relay 66 may be open, thereby connecting the first and second voltage sources 54a, 54b to the load 52, wherein the first and second voltage sources 54a, 54b are connected in series. In a second operating mode, the first relay 62 may be open, the second relay 64 may be closed, and the third relay 66 may be open, thereby connecting only the first voltage source 54a to the load 52. In a third operating mode, the first relay 62 may be open, the second relay 64 may be open, and the third relay 66 may be closed, thereby connecting only the second voltage source 54b to the load 52.In a fourth operating mode, the first relay 62 may be open, the second relay 64 may be closed, and the third relay 66 may be closed to thereby connect the first and second voltage sources 54a, 54b to the load 52, wherein the first and second voltage sources 54a, 54b are connected in parallel.

[0047] The circuit may further include a controller 70 configured to independently control the operation of the first relay 62, the second relay 64, and the third relay 66 between open and closed positions. Furthermore, the vehicle may be an electric vehicle, and the load 52 may include a DC link capacitor. Furthermore, the circuit may further include a precharge relay 68 operable between an open position and a closed position, wherein the precharge relay 68 may be connected in parallel with the positive main relay 56.

[0048] With reference to the Fig. 1A-1B, 2A-2D, and 3A-3C, the present disclosure describes a method for providing multi-modal electrical power to a load 52 in a vehicle having a first voltage source 54a and a second voltage source 54b, wherein the load 52 has a first side and a second side, the first voltage source 54a has a positive side and a negative side, and the second voltage source 54b has a positive side and a negative side. The method may include connecting a positive main relay 56 having a first side and a second side to the load 52 by connecting the second side of the positive main relay 56 to the first side of the load 52. The method may also include connecting a negative main relay 60 having a first and a second side to the vehicle load 52 by connecting the second side of the negative main relay 60 to the second side of the load 52.

[0049] The method may further include connecting a first relay 62 having a first side and a second side to the first voltage source 54a and the second voltage source 54b by connecting the first side of the first relay 62 to the positive side of the first voltage source 54a and the second side of the first relay 62 to the negative side of the second voltage source 54b. The method may also include connecting a second relay 64 having a first side and a second side to the first voltage source 54a, the second voltage source 54b, and the positive main relay 56 by connecting the first side of the second relay 64 to the positive side of the first voltage source 54a and the second side of the second relay 64 to the positive side of the second voltage source 54b and the first side of the positive main relay 56.Furthermore, the method may include connecting a third relay 66 having a first and a second side to the second voltage source 54b and the negative main relay 60 by connecting the first side of the third relay 66 to the negative side of the second voltage source 54b and connecting the second side of the third relay 66 to the first side of the negative main relay 60.

[0050] The method may also include providing electrical load from the first voltage source 54a and / or the second voltage source 54b to the vehicle 52 according to one of a plurality of operating modes by opening or closing each of the first relay 62, the second relay 64, and the third relay 66. In this regard, as previously described, each of the first relay 62, the second relay 64, and the third relay 66 may be independently operable between an open position and a closed position.

[0051] The plurality of operating modes may include a first operating mode, and providing electrical energy according to the first operating mode may include closing the first relay 62, opening the second relay 64, and opening the third relay 66 to thereby connect the first and second voltage sources 54a, 54b to the vehicle load 52, wherein the first and second voltage sources 54a, 54b are connected in series. The plurality of operating modes may also include a second operating mode, and providing electrical energy according to the second operating mode may include opening the first relay 62, closing the second relay 64, and opening the third relay 66 to thereby connect only the first voltage source 54a to the load 52.The plurality of operating modes may also include a third operating mode, and providing electrical energy according to the third operating mode may include opening the first relay 62, opening the second relay 64, and closing the third relay 66 to thereby connect only the second voltage source 54b to the load 52. The plurality of operating modes may also include a fourth operating mode, and providing electrical energy according to the fourth operating mode may include opening the first relay 62, closing the second relay 64, and closing the third relay 66 to thereby connect the first and second voltage sources 54a, 54b to the load 52, wherein the first and second voltage sources 54a, 54b are connected in parallel.

[0052] The vehicle may comprise an electric vehicle, and the load 52 may comprise a DC link capacitor. The method may further comprise connecting a precharge relay 68 operable between an open position and a closed position in parallel with the positive main relay 56, and closing the precharge relay 68 prior to opening or closing the first relay 62, the second relay 64, and / or the third relay 66.

[0053] Still referring to the Fig. 1A-1B, 2A-2D and 3A-3C, the present disclosure describes a non-transitory computer-readable storage medium having computer-executable instructions for providing multi-modal electrical power to a load 52 in a vehicle, the vehicle comprising (i) a first voltage source 54a having a positive side and a negative side, (ii) a second voltage source 54b having a positive side and a negative side, (iii) a positive main relay 56 having a first side and a second side, the second side of the positive main relay 56 being connected to a first side of the load 52, (iv) a negative main relay 60 having a first side and a second side, the second side of the negative main relay 60 being connected to a second side of the load 52, (v) a first relay 62,which is operable between an open position and a closed position, wherein the first relay 62 has a first side and a second side, the first side of the first relay 62 being connected to the positive side of the first voltage source 54a, and the second side of the first relay 62 being connected to the negative side of the second voltage source 54b, (vi) a second relay 64 operable between an open position and a closed position, wherein the second relay 64 has a first side and a second side, the first side of the second relay 64 being connected to the positive side of the first voltage source 54a, and the second side of the second relay 64 being connected to the positive side of the second voltage source 54b and the first side of the positive main relay 56, (vii) a third relay 66 operable between an open position and a closed position,wherein the third relay 66 has a first side and a second side, the first side of the third relay 66 being connected to the negative side of the second voltage source 54b and the second side of the third relay 66 being connected to the first side of the negative main relay 60, and (viii) a controller 70 configured to independently control the operation of the first relay 62, the second relay 64, and the third relay 66 between open and closed positions.

[0054] The computer-executable instructions may be configured to cause the controller 70 to provide electrical power from the first voltage source 54a and / or the second voltage source 54b to operate the electrical load of the vehicle 52 according to one of a plurality of operating modes based on the open or closed positions of the first relay 62, the second relay 64, and the third relay 66. In this regard, the plurality of operating modes may include a first operating mode, and to provide electrical load according to the first operating mode, the computer-executable instructions may be configured to cause the controller 70 to close the first relay 62, open the second relay 64, and open the third relay 66, thereby connecting the first and second voltage sources 54a, 54b to the load 52, wherein the first and second voltage sources 54a, 54b are connected in series.The plurality of operating modes may include a second operating mode, and to provide electrical power according to the second operating mode, the computer-executable instructions may be configured to cause the controller 70 to open the first relay 62, close the second relay 64, and open the third relay 66, thereby connecting only the first voltage source 54a to the load 52. The plurality of operating modes may also include a third operating mode, and to provide electrical power according to the third operating mode, the computer-executable instructions are configured to cause the controller 70 to open the first relay 62, open the second relay 64, and close the third relay 66, thereby connecting only the second voltage source 54b to the load 52.The plurality of operating modes may further include a fourth operating mode, and to provide electrical load according to the fourth operating mode, the computer-executable instructions are configured to cause the controller 70 to open the first relay 62, close the second relay 64, and close the third relay 66 to thereby connect the first and second voltage sources 54a, 54b to the load 52, wherein the first and second voltage sources 54a, 54b are connected in parallel.

[0055] The vehicle may comprise an electric vehicle, and the load 52 may comprise a direct current (DC) link capacitor. A precharge relay 68 operable between an open position and a closed position may be connected in parallel with the positive main relay 56, and the computer-executable instructions may be configured to cause the controller 70 to close the precharge relay 68 before opening or closing any of the first relay 62, the second relay 64, and / or the third relay 66. As previously described, the computer-executable instructions described herein may be stored in or on a computer-readable storage medium, which may comprise any known type of storage medium or device, and may be part of or connected to the controller 70.

[0056] The present disclosure therefore describes an improved circuit and method for providing multimodal electrical power to an electrical load in a vehicle. The improved circuit and method of the present disclosure provide a high-voltage architecture topology for an electric vehicle that reduces the number of required components. For example, the Fig. 1B, the topology 50 shown only has a single precharge relay 68 and an associated precharge resistor, while the topology shown in Fig.1A utilizes two precharge relays 16a, 16b and two associated precharge resistors. The improved circuit and method of the present disclosure thereby reduce both the cost and the number of associated potential failure points. The improved circuit and method also provide a simplified and / or improved relay control sequence for detecting the status of relays in a high-voltage architecture and for providing multiple types of current to an electrical load in the vehicle. For example, topology 50 advantageously implements a high-voltage architecture compatible with multiple operating modes (e.g., 800V / 400V).

Claims

[1] A circuit for providing multimodal electrical energy to a load (52) in a vehicle, the circuit comprising: a first voltage source (54a) having a positive side and a negative side; a second voltage source (54b) having a positive side and a negative side; a positive main relay (56) having a first side and a second side, the second side of the positive main relay (56) being connected to a first side of the load (52); a negative main relay (60) having a first side and a second side, the second side of the negative main relay (60) being connected to a second side of the load (52); a first relay (62) operable between an open position and a closed position, the first relay (62) having a first side and a second side, the first side of the first relay (62) being connected to the positive side of the first voltage source (54a), and the second side of the first relay (62) being connected to the negative side of the second voltage source (54b); a second relay (64) operable between an open position and a closed position, the second relay (64) having a first side and a second side, the first side of the second relay (64) being connected to the positive side of the first voltage source (54a) and the second side of the second relay (64) being connected to the positive side of the second voltage source (54b) and the first side of the positive main relay (56); and a third relay (66) operable between an open position and a closed position, the third relay (66) having a first side and a second side, the first side of the third relay (66) being connected to the negative side of the second voltage source (54b) and the second side of the third relay (66) being connected to the first side of the negative main relay (60). [2] The circuit of claim 1, wherein electrical energy is supplied from the first voltage source (54a) and / or the second voltage source (54b) according to one of a plurality of operating modes based on the open or closed positions of the first, second and third relays (62, 64, 66). [3] The circuit of claim 1 or 2, wherein in a first operating mode, the first relay (62) is closed, the second relay (64) is open, and the third relay (66) is open to thereby connect the first and second voltage sources (54b) to the load (52), the first and second voltage sources (54b) being connected in series. [4] A circuit according to any one of the preceding claims, wherein in a second operating mode the first relay (62) is open, the second relay (64) is closed and the third relay (66) is open to thereby connect only the first voltage source (54a) to the load (52). [5] A circuit according to any one of the preceding claims, wherein in a third mode of operation the first relay (62) is open, the second relay (64) is open and the third relay (66) is closed to thereby connect only the second voltage source (54b) to the load (52). [6] A circuit according to any one of the preceding claims, wherein in a fourth operating mode the first relay (62) is open, the second relay (64) is closed and the third relay (66) is closed to thereby connect the first and second voltage sources (54b) to the load (52), the first and second voltage sources (54b) being connected in parallel. [7] A circuit according to any preceding claim, further comprising a controller (70) configured to independently control the operation of the first, second and third relays (62, 64, 66) between open and closed positions. [8] A circuit according to any one of the preceding claims, wherein the load (52) comprises a DC link capacitor, the circuit further comprising a precharge relay (68) operable between an open position and a closed position, the precharge relay (68) being connected in parallel with the positive main relay (56). [9] A method for providing multimodal electrical energy to a load (52) in a vehicle having a first voltage source (54a) and a second voltage source (54b), the load (52) having a first side and a second side, the first voltage source (54a) having a positive side and a negative side, and the second voltage source (54b) having a positive side and a negative side, the method comprising: Connecting a positive main relay (56) having a first side and a second side to the load (52) by connecting the second side of the positive main relay (56) to the first side of the load (52); Connecting a negative main relay (60) having a first side and a second side to the load (52) by connecting the second side of the negative main relay (60) to the second side of the load (52); Connecting a first relay (62) having a first side and a second side to the first voltage source (54a) and the second voltage source (54b) by connecting the first side of the first relay (62) to the positive side of the first voltage source (54a) and connecting the second side of the first relay (62) to the negative side of the second voltage source (54b); Connecting a second relay (64) having a first side and a second side to the first voltage source (54a), the second voltage source (54b) and the positive main relay (56) by connecting the first side of the second relay (64) to the positive side of the first voltage source (54a) and the second side of the second relay (64) to the positive side of the second voltage source (54b) and the first side of the positive main relay (56); Connecting a third relay (66) having a first side and a second side to the second voltage source (54b) and the negative main relay (60) by connecting the first side of the third relay (66) to the negative side of the second voltage source (54b) and connecting the second side of the third relay (66) to the first side of the negative main relay (60); wherein each of the first, second and third relays (62, 64, 66) is independently operable between an open position and a closed position; and Supplying electrical energy from the first voltage source (54a) and / or the second voltage source (54b) to provide the electrical energy of the vehicle according to one of a plurality of operating modes by opening or closing each of the first, second and third relays (62, 64, 66). [10] The method of claim 9, wherein the plurality of operating modes comprises a first operating mode and providing electrical power according to the first operating mode comprises: Closing the first relay (62); Opening the second relay (64); and Opening the third relay (66); to thereby connect the first and second voltage sources (54b) to the load (52), wherein the first and second voltage sources (54b) are connected in series. [11] The method of claim 9 or 10, wherein the plurality of operating modes includes a second operating mode and providing electrical power according to the second operating mode comprises: Opening the first relay (62); Closing the second relay (64); and Opening the third relay (66); to thereby connect only the first voltage source (54a) to the load (52) of the vehicle. [12] The method of any one of claims 9 to 11, wherein the plurality of operating modes includes a third operating mode and providing electrical power according to the third operating mode comprises: Opening the first relay (62); Opening the second relay (64); and Closing the third relay (66); to thereby connect only the second voltage source (54b) to the load (52) of the vehicle. [13] The method of any one of claims 9 to 12, wherein the plurality of operating modes includes a fourth operating mode and providing electrical power according to the fourth operating mode comprises: Opening the first relay (62); Closing the second relay (64); and Closing the third relay (66); to thereby connect the first and second voltage sources (54b) to the load (52) of the vehicle, wherein the first and second voltage sources (54b) are connected in parallel. [14] The method of any one of claims 9 to 13, wherein the load (52) comprises a DC link capacitor, the method further comprising: Connecting a precharge relay (68) operable between an open position and a closed position in parallel with the positive main relay (56); and Closing the pre-charge relay (68) before any of the first, second and third relays (62, 64, 66) are opened or closed. [15] A non-transitory computer-readable storage medium having stored computer-executable instructions for providing multimodal electrical power to a load (52) in a vehicle, the vehicle comprising: (i) a first voltage source (54a) having a positive side and a negative side, (ii) a second voltage source (54b) having a positive side and a negative side, (iii) a positive main relay (56) having a first side and a second side, the second side of the positive main relay (56) being connected to a first side of the load (52), (iv) a positive main relay (56) having a first side and a second side, the second side of the negative main relay (60) being connected to a second side of the load (52), (v) a first relay (62) operable between an open position and a closed position, the first relay (62) having a first side and a second side,wherein the first side of the first relay (62) is connected to the positive side of the first voltage source (54a), and the second side of the first relay (62) is connected to the negative side of the second voltage source (54b), (vi) a second relay (64) operable between an open position and a closed position, the second relay (64) having a first side and a second side, the first side of the second relay (64) being connected to the positive side of the first voltage source (54a), and the second side of the second relay (64) being connected to the positive side of the second voltage source (54b) and the first side of the positive main relay (56), (vii) a third relay operable between an open position and a closed position,wherein the third relay (66) has a first side and a second side, the first side of the third relay (66) being connected to the negative side of the second voltage source (54b) and the second side of the third relay (66) being connected to the first side of the negative main relay (60), and (viii) a controller (70) configured to independently control the operation of the first, second and third relays (62, 64, 66) between the open and closed positions, the computer-executable instructions being configured to cause the controller (70) to: Providing electrical power from the first voltage source (54a) and / or the second voltage source (54b) to the load (52) according to one of a plurality of operating modes based on the open or closed positions of the first, second and third relays (62, 64, 66). [16] The non-transitory computer-readable storage medium of claim 15, wherein the plurality of operating modes includes a first operating mode, and, to provide electrical energy according to the first operating mode, the computer-executable instructions are configured to cause the controller (70) to: to close the first relay (62); to open the second relay (64); and to open the third relay (66); to thereby connect the first and second voltage sources (54b) to the load (52), wherein the first and second voltage sources (54b) are connected in series. [17] The non-transitory computer-readable storage medium of claim 15 or 16, wherein the plurality of operating modes includes a second operating mode, and, to provide electrical energy according to the second operating mode, the computer-executable instructions are configured to cause the controller (70) to: to open the first relay (62); to close the second relay (64); and to open the third relay (66); to thereby connect only the first voltage source (54a) to the load (52). [18] The non-transitory computer-readable storage medium of any one of claims 15 to 17, wherein the plurality of operating modes includes a third operating mode, and, to provide electrical energy according to the third operating mode, the computer-executable instructions are configured to cause the controller (70) to: to open the first relay (62); to open the second relay (64); and to close the third relay (66); to thereby connect only the second voltage source (54b) to the load (52). [19] The non-transitory computer-readable storage medium of any one of claims 15 to 18, wherein the plurality of operating modes includes a fourth operating mode, and, to provide electrical energy according to the fourth operating mode, the computer-executable instructions are configured to cause the controller (70) to: to open the first relay (62); to close the second relay (64); and to close the third relay (66); to thereby connect the first and second voltage sources (54b) to the load (52), wherein the first and second voltage sources (54b) are connected in parallel. [20] The non-transitory computer-readable storage medium of any one of claims 15 to 19, wherein the load (52) comprises a DC link capacitor, wherein a precharge relay (68) operable between an open position and a closed position is connected in parallel with the positive main relay (56), and wherein the computer-executable instructions are configured to cause the controller (70) to close the precharge relay (68) before opening or closing any of the first, second, and third relays (62, 64, 66).

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