Electric drive machine having electrical distribution unit configured for emergency operation and method

Abstract

An electric drive machine includes an electric drive system configured to operate a ground engaging propulsion element, a power distribution unit (PDU), and a plurality of electric accessories arranged in a first accessory set and a second accessory set. The PDU includes: a first bus electrically connected to a plurality of accessories in a first accessory group and at least one accessory in a second accessory group; a second bus electrically connected to the plurality of accessories in the second accessory group and at least one accessory in the first accessory group; a first contactor electrically connected to the first bus; and a second contactor electrically connected to the second bus. The electric drive machine has a full power mode in which each of the first and second contactors in the PDU is turned on, and the electric drive machine is adjustable to an emergency operating mode in which one of the first or second contactors is turned on, and the other of the first contactor or the second contactor is switched off. Related methods are also disclosed.

Description

Technical Field

[0001] The present invention generally relates to operating an electric drive machine, and more particularly to switching an electric drive machine from a full power mode to an emergency operation mode. Background Art

[0002] In recent years, various industries have started to shift from traditional energy sources such as fossil fuels to electricity. For example, all-electric and hybrid vehicles have become common in the national transportation infrastructure. Some other industries have now adopted electrification to some extent, but have not realized the full theoretical potential of electricity.

[0003] In construction, mining, and certain other industries, machines that utilize complex mechanical parts energized with diesel-electric drive systems have experienced commercial success. Fully electrified machine fleets have been proposed, particularly in mining environments, where mining trucks can be selectively connected to an external power source and operate on stored electrical energy when such a direct connection is not readily available.

[0004] With any new and emerging technological efforts on powered machines, various new problems have been posed. All-electric machinery, particularly in complex and heavy machine systems, can be associated with thousands of possibilities for short circuits and other fault conditions during use. The standard practice for resolving a faulty electrical system in complex electrified machinery is to completely shut down operation. Of course, removing the machine from process service incurs costs due to reduced productivity. Complicating these issues is that the machine may be stopped in a location where inspection and / or repair is very inconvenient, regardless of where the problem occurs or is detected. An example of an electric drive machine is known from U.S. Patent Application Publication No. 20140021898A1 to Hendrickson et al. Summary of the Invention

[0005] In one aspect, an electric drive machine includes a frame and ground engaging propulsion elements coupled to the frame. The electric drive machine further includes an electric drive system having at least one electric drive motor configured to operate the ground engaging propulsion elements, a power distribution unit (PDU), and a plurality of electric accessories arranged in a first accessory group and a second accessory group. The PDU includes: a first bus electrically connected to a plurality of accessories in the first accessory group and at least one accessory in the second accessory group; a second bus electrically connected to a plurality of accessories in the second accessory group and at least one accessory in the first accessory group; a first contactor electrically connected to the first bus; and a second contactor electrically connected to the second bus. The electric drive machine has a full power mode in which each of the first contactor and the second contactor in the PDU is closed, and the electric drive machine is adjustable to an emergency operation mode in which one of the first contactor or the second contactor is closed and the other of the first contactor or the second contactor is open.

[0006] In another aspect, a method of operating an electric drive machine includes: operating the electric drive machine in a full power mode in which a first contactor electrically connected to a first bus and a second contactor electrically connected to a second bus in a power distribution unit (PDU) are each closed; and in the full power mode of the electric drive machine, supplying power from the PDU to a plurality of accessories in the first accessory group and at least one accessory in the second accessory group via the first bus, and supplying power to a plurality of accessories in the second accessory group and at least one accessory in the first accessory group via the second bus. The method further includes switching the first contactor to open; operating the electric drive machine in an emergency operation mode based on switching the first contactor to open; and in the emergency operation mode of the electric drive machine, supplying power from the PDU to a plurality of accessories in the second accessory group and to at least one accessory in the first accessory group via the second bus.

[0007] In yet another aspect, an electric drive system for a machine includes a power distribution unit (PDU) that includes a power input device, a first switching circuit, a second switching circuit, and a non-switching circuit. The first switching circuit includes a first bus and a first contactor electrically connected between the first bus and the power input device, the second switching circuit includes a second bus and a second contactor electrically connected between the second bus and the power input device, and the non-switching circuit includes a third bus. The electric drive system further includes a plurality of electric accessories arranged in a first accessory group, a second accessory group, and a third accessory group. The first accessory group includes a plurality of accessories connected in parallel to the first bus and at least one accessory connected across to the second bus, and the second accessory group includes a plurality of accessories connected in parallel to the second bus and at least one accessory connected across to the first bus. The PDU is operable in a full power mode in which each of the first and second contactors in the PDU is closed, and the electric drive machine is adjustable to an emergency operation mode in which one of the first or second contactors is closed and the other of the first or second contactors is open. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 is a side view of an electric drive machine according to one embodiment;

[0009] Figure 2 is a schematic diagram of an auxiliary system of an electric drive system for an electric drive machine according to one embodiment;

[0010] Figure 3 is an illustration of a power distribution unit (PDU) of an electric drive system for an electric drive machine according to one embodiment; and

[0011] Figure 4 is a flowchart showing an exemplary method according to one embodiment. DETAILED DESCRIPTION

[0012] See Figure 1, shows an electric drive machine 10 according to one embodiment. The machine 10 includes a frame 12, a ground engaging propulsion element 14 coupled to the frame 12, and an electric drive system 16. The machine 10 is shown in the context of a mining truck that has a dump body 19 that can be raised and lowered in a generally conventional manner. An operator cab 17 is supported on the frame 12. In the illustrated embodiment, the ground engaging element 14 is shown as wheels. In other cases, the machine 10 can be equipped with ground engaging tracks, or in some cases even have a semi-track configuration. In addition to mining trucks, the present invention can also be implemented in other machines, such as tractors, graders, loaders, scrapers, and other machines. The electric drive system 16 can include at least one electric drive motor 18 configured to operate the ground engaging propulsion element 14. The illustrated machine 10 is configured with individual wheel motors 18. In other embodiments, a single electric drive motor can be provided that operates the ground engaging propulsion element 14 together, or in a front-wheel drive or rear-wheel drive arrangement. The electric drive system 16 can also include a transmission coupled between some or all of the electric drive motor and the ground engaging propulsion element 14. The electric drive machine 10 can be fully powered and operate the electric drive system 16 through a battery array or battery pack 20 that includes one or more batteries. In addition, in addition to or instead of batteries, other electrical energy storage devices, such as capacitors, can also be used. The electric drive machine 10 can further be configured to charge the battery pack 20 by plugging in a battery charger when idle or by connecting to an overhead trolley wire or an external power rail. The electric drive machine 10 can also include an internal combustion engine that is coupled to a generator to provide electrical power for propulsion or any other purpose.

[0013] As discussed above, electric drive systems can be complex. Especially in the case of fully electrified machines, thousands of electrical connections on the machine can create a large number of opportunities for electrical fault conditions, such as ground faults or other problems. When a ground fault or other electrical problem occurs anywhere in the electric drive system, a common practice for certain types of machinery is to completely shut down operation until the time when the fault can be cleared. As will be further readily understood from the following description, the machine 10 can operate in a full power mode, but when a fault occurs, it switches to an emergency operating mode that is less than full power, and the machine may be required to stop and evaluate service for a certain period of time.

[0014] The operator alert or alert device 36 may be located in the cab 17. In some embodiments, when the machine 10 transitions to the emergency operation mode, a countdown timer may be initiated, and the operator may be notified that the emergency operation mode is enabled and the remaining time, for example, before the electric drive system 16 will be fully disabled may be displayed. This capability may enable the operator to be notified that a ground fault, electrical disconnection, or other electrical problem has occurred while giving sufficient time to drive the machine 10 to an appropriate idle or service position.

[0015] The electric drive system 16 may also include motor drive electronics 22, typically including one or more inverters, that provide and condition the power supplied from the battery pack 20 to one or more electric drive motors 18. The electric drive system 16 also includes an auxiliary system 24. The auxiliary system 24 may include a plurality of electric accessories 28 and a power distribution unit (PDU) 26. The electric accessories 28 may include various different accessories that control, operate, and monitor the various systems and subsystems on the machine 10. In one implementation, the plurality of electric accessories 28 includes temperature control accessories that control the temperature of the various different on-board components and systems in the machine 10, and each on-board component and system has an electric motor, as further discussed herein.

[0016] Reference is now also made to Figure 2 , in which the features of the auxiliary system 24 are shown in more detail. The accessories 28 may be arranged in a first accessory group 30 and a second accessory group 32. In some implementations, each of the first accessory group 30 and the second accessory group 32 may include at least one of a pump, a compressor, or a fan. The machine 10 may include a first plurality of temperature-sensitive components that are temperature-controlled by the first accessory group 30, and a second plurality of temperature-sensitive components that are temperature-controlled by the second accessory group 32. The temperature-sensitive elements may include electrical energy storage devices, such as batteries that are operable or optimally operable within a relatively narrow temperature range.

[0017] The first accessory group 30 may include a first battery thermal management system (BTMS1) 38 and a second battery thermal management system (BTMS2) 40. The second accessory group 32 may include a third battery thermal management system (BTMS3) 42 and a fourth battery thermal management system (BTMS4) 44. Each of BTMS1-4 may include an electric accessory configured to control the temperature of one of a plurality of batteries. In the illustrated embodiment, BTMS1 includes a plurality of compressors 54 and a plurality of fans 56, the plurality of compressors 54 and the plurality of fans 56 being configured to compress a refrigerant fluid and circulate the refrigerant fluid in heat transfer contact with the first battery (BATT1) 46. BTMS2 includes a compressor 58 and a fan 60, BTMS3 includes a compressor 62 and a fan 64, and BTMS4 includes a compressor 66 and a fan 68. BTMS2 is associated with the second battery (BATT2) 48, BTMS3 is associated with the third battery (BATT3) 50, and BTMS4 is associated with the fourth battery (BATT4) 52. BTMS1-4 may generally be functionally similar to each other, compressing and circulating a refrigerant fluid for battery cooling via respective compressors and cooling the refrigerant via respective fans. The accessory 28 may also include a plurality of battery heaters 94. It should be understood that any arrangement and combination of components for thermally managing an electrical energy storage device or other temperature-sensitive components via at least one of cooling or heating, such as the batteries discussed herein, and Figure 2 only one example is shown.

[0018] The electric drive system 16 may also include a plurality of fluid circuits for delivering a cooling fluid to exchange heat with the refrigerant in BTMS1-4 and / or with other possible fluids of components in BATT1-4 or the machine 10. In the illustrated embodiment, the first fluid path 70 includes a first fluid circuit 72 and a second fluid circuit 74 respectively associated with BTMS1 and BTMS2, and a common manifold 76. A cooling fluid such as engine coolant, water, or various mixtures may circulate in the fluid path 70. The second fluid path 78 is associated with BTMS3 and BTMS4 and includes a first fluid circuit 80, a second fluid circuit 82, and a common manifold 84. Each of the first accessory group 30 and the second accessory group 32 may include at least one accessory working fluid connected to a respective one of the first fluid path 70 and the second fluid path 78. An accessory working fluid connection means that the accessory acts on the working fluid, for example, by compressing, expanding, or delivering.

[0019] The accessory 28 may also include one or more fans 90 and an electric blower 92, the fans 90 being configured to cool other components of the machine 10, such as power electronics in the electric drive system 16.

[0020] It will be recalled that the electric drive machine 10 can be operated in a full power mode as well as an emergency operation mode. It has been observed that when full power in the electric drive system 16 is unavailable due to a fault or other problem, some power can still be provided by selectively using non-faulty portions of the electric drive system 16, including some of the accessories 28. However, it has been observed that even when full power is unavailable, some temperature control of some locations or components in the electric drive system 16 is still desirable. The present invention addresses these and other problems by selectively providing power to certain components of the electric drive system 16 such that one or more electric drive motors 18 can still operate without pausing temperature control of temperature-sensitive components such as batteries or other components.

[0021] To this end, the PDU includes a first bus 106 electrically connected to a plurality of accessories in the first accessory group 30 and at least one accessory in the second accessory group 32. The PDU 26 also includes a second bus 110 electrically connected to a plurality of accessories in the second accessory group 32 and at least one accessory in the first accessory group 30. As can be seen from Figure 2 it, the electrical connection line 108 is connected between the first bus 106 and the BTMS1 to provide electrical energy to the compressor 54 and the fan 56. The electrical connection line 109 electrically connects the first bus 106 to the BTMS3 to supply power to the compressor 62 and the fan 64. The wire 112 electrically connects the second bus 110 to the BTMS4, and the wire 113 connects the second bus 110 to the BTMS2.

[0022] From the foregoing description, it can be understood that the first accessory group 30 includes accessories associated with the first plurality of temperature-sensitive elements (i.e., BATT1 and BATT2). The second accessory group 32 includes a plurality of accessories associated with BATT3 and BATT4. A fluid passage 70 is provided, and the fluid passage 70 shares cooling fluid through a common shunt box 76 between the BTMS1 and the BTMS2. A fluid passage 78 provides cooling fluid through a fluid circuit 80 and a fluid circuit 82 and a shunt box 84 associated with BATT3 and BATT4. The electrical connections of several BTMS modules can be understood as jumper connections with respect to the functional temperature control connections between the corresponding first accessory group 30 and the second accessory group 32. In other words, although the accessories in the first accessory group 30 control the temperature of the same temperature-sensitive components, the individual accessories do not share the same power source. The second accessory group 32 is configured similarly.

[0023] The PDU 26 also includes a first contactor 114 electrically connected to the first bus 106 and a second contactor 116 electrically connected to the second bus 110. As described above, the electric drive machine 10 has a full power mode in which each of the first contactor 114 and the second contactor 116 in the PDU 26 is turned on. The electric drive machine 10 can be adjusted to an emergency operation mode in which one of the first contactor 114 or the second contactor 116 is turned on while the other of the first contactor 114 or the second contactor 116 is turned off. For example, the first contactor 114 and the second contactor 116 can switch from an on state, in which the corresponding bus is energized, to an off state, in which the corresponding bus is de-energized, in response to a ground fault. The electric drive system 16 can also be configured via a high voltage interlock loop (HVIL) to switch either the first contactor 114 or the second contactor 116 to off in cases other than when a ground fault occurs (e.g., when a non-tool disconnect of an electric component occurs). In this general manner, the electric drive system 16 can be protected from ground faults and disconnects that pose a risk of arc flash or other problems. The "contactors" contemplated herein include electrical devices that can switch between a first state (ON) providing an electrical connection and a second state (OFF) in which the electrical connection is interrupted. Suitable contactors can be those sold under the name such as those available from Sensata Technologies.

[0024] The PDU 26 can also include a third bus 118. The third bus 118 can be electrically connected to a third accessory group 34. In one implementation, the third bus 118 can be electrically connected to the third accessory group 34 without being electrically connected to any accessory in the first accessory group 30 and the second accessory group 32. The third accessory group 34 can include a water pump 98 for circulating water or coolant to, for example, a motor, a brake, a battery, or other components in the machine 10, and a DC-DC converter 96, such as a 24-volt DC-DC converter. The DC-DC converter 96 can be electrically connected to a plurality of electronic control modules 128 in the electric drive system 16. The electronic control modules 128 can include one or more motor control modules, transmission control modules, steering devices, implements, or other computerized control modules. In the event of a ground fault or other electrical problem in the third accessory group 34, it may generally be desirable to completely disable the machine 10. Accordingly, the third bus 118 can be electrically isolated from all accessories other than the third accessory group 34. Additional auxiliary accessories or accessory groups can optionally be electrically connected to the first bus 106, the second bus 110, and the third bus 118, including a first auxiliary accessory 100, a second auxiliary accessory 102, and a third auxiliary accessory 104.

[0025] Now also referring to Figure 3, showing more details of the PDU 26. The PDU 26 may have an input power or power input device 120 that feeds power to each of the first bus 106, the second bus 110, and the third bus 118. In the illustrated embodiment, the PDU 26 includes a first switching circuit 122, a second switching circuit 124, and a non-switching circuit 126. The first switching circuit 122 includes the first bus 106, the second switching circuit 124 includes the second bus 110, and the non-switching circuit 126 includes the third bus 118. A first contactor 116 is electrically connected between the input device 120 and the first bus 106. A second contactor 116 is electrically connected between the input device 120 and the second bus 110. Additional contactors 115 and 117 may be electrically connected between the first bus 106 and the second bus 110 and the third bus 118, respectively. The first attachment group 30 of the components depicted in Figure 3 may include a plurality of attachments connected in parallel to the first bus 106 and at least one attachment connected across to the second bus 110. The second attachment group 32 may include a plurality of attachments connected in parallel to the second bus 110 and at least one attachment connected across to the first bus 106.

[0026] From these illustrations, it can be understood that the attachments 86, 88, BTMS1, and auxiliary attachment 102 can be understood as being connected in parallel to the first bus 106. BTMS3 is part of the second attachment group 32 and is thus understood as being connected across to the first bus 106. BTMS4, fan 90, electric blower 92, battery heater 94, and auxiliary attachment 104 are connected in parallel to the second bus 110, and BTMS2 is connected across to the second bus 110. Just as when operating the machine 10 in the full-power mode or the emergency operation mode, the PDU 26 can be operated in the full-power mode, where each of the first contactor 114 and the second contactor 116 is turned on, and the PDU 26 can be adjusted to operate in the emergency operation mode, where one of the first contactor 114 or the second contactor 116 is turned on while the other of the first contactor 114 and the second contactor 116 is turned off.

[0027] Industrial Applicability

[0028] Generally referring to the accompanying drawings, but now also focusing on Figure 4Above, a flowchart 200 showing an exemplary method according to an embodiment is shown. At block 210, the electric drive machine 10 operates in a full power mode, in which each of a first contactor 114 and a second contactor 116 respectively connected to a first bus 106 and a second bus 110 is turned on. The flowchart 200 proceeds from block 210 to block 215 so as to supply power from the PDU 26 to a plurality of accessories in the first accessory group 30 and at least one accessory in the second accessory group 32 via the first bus 106, and to a plurality of accessories in the second accessory group 32 and at least one accessory in the first accessory group 30 via the second bus 110 in the full power mode of the electric drive machine 10. The flowchart 200 proceeds from block 215 to block 220 to create a ground fault. For example, creating a ground fault may include an electrical short circuit.

[0029] From block 220, the flowchart 200 proceeds to block 225 to switch one of the first contactor 114 or the second contactor 116 to off. The flowchart 200 proceeds from block 225 to block 230 so as to operate the machine 10 in an emergency operation mode based on switching one of the first contactor 114 or the second contactor 116 to off. Operating the electric drive machine 10 in the emergency operation mode may further include starting a countdown timer based on switching one of the first contactor 114 or the second contactor 116 to off, and the countdown timer turns on the operator alert 36 or is associated with the operator alert 36. The power of the electric drive system 16 may be completely turned off based on the end of the countdown timer, for example, after ten minutes, twenty minutes, etc. have passed.

[0030] From block 230, the flowchart 200 may proceed to block 235 so as to supply power from the PDU 26 to the first accessory group 30 and the second accessory group 32 in the emergency operation mode. At this point, the batteries in the battery pack 20 may be operated at a reduced power such that the electric drive system 16 is only provided with enough power to operate the machine 10 at a relatively slow or medium speed to reach a suitable service location. At the same time, due to the cross-connection of power between the first accessory group 30 and the second bus 110, or between the second accessory group 32 and the first bus 106, some temperature control of all the batteries will continue. In other words, because some fluid delivery to all the BTMS modules continues in the emergency operation mode, the batteries and associated components are substantially less likely to overheat.

[0031] This specification is for illustrative purposes only and should not be construed as narrowing the breadth of the present invention in any way. Accordingly, those skilled in the art will appreciate that various modifications can be made to the presently disclosed embodiments without departing from the full and fair scope and spirit of the present invention. Other aspects, features, and advantages will be readily understood by examining the drawings and the appended claims. As used herein, the articles "a" and "an" are intended to include one or more items and may be used interchangeably with "one or more." Where only one item is intended, the term "one" or similar language is used. Further, as used herein, the terms "has," "have," "having," or similar terms are intended to be open-ended terms. Additionally, the phrase "based on" is intended to mean "at least partially based on" unless otherwise expressly stated.

Claims

1. An electric drive machine, comprising: Frame; A ground engaging propulsion element coupled to the frame; An electric drive system including at least one electric drive motor configured to operate the ground engaging propulsion element, a power distribution unit (PDU), and a plurality of electric accessories arranged in a first accessory group and a second accessory group; The PDU includes a first bus electrically connected to a plurality of accessories in the first accessory group and at least one accessory in the second accessory group, a second bus electrically connected to a plurality of accessories in the second accessory group and at least one accessory in the first accessory group, a first contactor electrically connected to the first bus, and a second contactor electrically connected to the second bus; And The electric drive machine has a full power mode in which each of the first contactor and the second contactor in the PDU is turned on, and the electric drive machine is adjustable to an emergency operation mode in which one of the first contactor or the second contactor is turned on and the other of the first contactor or the second contactor is turned off.

2. The electric drive machine according to claim 1, wherein, The plurality of electric accessories includes a plurality of temperature control accessories, each of the temperature control accessories having an electric motor.

3. The electric drive machine according to claim 2, wherein, Each of the first accessory group and the second accessory group includes at least one of a pump, a compressor, or a fan.

4. The electric drive machine according to claim 3, further comprising a first plurality of temperature-sensitive components controlled by the temperature of the first accessory group, and a second plurality of temperature-sensitive components controlled by the temperature of the second accessory group.

5. The electric drive machine according to claim 4, wherein, Each of the first and second plurality of temperature sensitive components includes an energy storage device.

6. The electric drive machine according to claim 5, wherein, Each of the energy storage devices includes a battery.

7. The electric drive machine according to claim 4, further comprising a first fluid passage and a second fluid passage, and the first accessory group includes at least one accessory working fluid connected to the first fluid passage, and the second accessory group includes at least one accessory working fluid connected to the second fluid passage.

8. The electric drive machine according to claim 7, wherein the first fluid passage includes a plurality of fluid circuits and a first common flow distribution box; and the second fluid passage includes a plurality of fluid circuits and a second common flow distribution box.

9. The electric drive machine according to claim 1, wherein, The plurality of accessories includes a third accessory group, and the PDU includes a third bus electrically connected to a plurality of accessories in the third accessory group but not electrically connected to any accessories in the first accessory group and the second accessory group.

10. The electric drive machine according to claim 9, wherein, The third accessory group includes a DC-DC power supply electrically connected to at least one electronic control module in the electric drive machine.

11. A method of operating an electric drive machine, comprising: Operating the electric drive machine in full power mode, wherein each of a first contactor electrically connected to the first bus and a second contactor electrically connected to the second bus in the power distribution unit (PDU) is turned on; In the full power mode of the electric drive machine, supplying power from the PDU to a plurality of accessories in the first accessory group and at least one accessory in the second accessory group via the first bus, and supplying power to a plurality of accessories in the second accessory group and at least one accessory in the first accessory group via the second bus; Switching the first contactor to off; Operating the electric drive machine in emergency operation mode based on switching the first contactor to off; And In the emergency operation mode of the electric drive machine, supplying power from the PDU to the plurality of accessories in the second accessory group and the at least one accessory in the first accessory group via the second bus.

12. The method according to claim 11, wherein, Each of the first accessory group and the second accessory group includes a plurality of temperature control accessories.

13. The method according to claim 12 further comprises controlling the temperature of a plurality of temperature-sensitive components in each of the full-power mode and the emergency operation mode.

14. The method according to claim 13, wherein The plurality of temperature sensitive components includes a plurality of batteries.

15. The method according to claim 13, wherein The controlled temperature further includes conveying temperature control fluid in a fluid passage by at least one of the accessories of the first accessory group electrically connected to the second bus during operation of the electric drive machine in the emergency operation mode.

16. The method according to claim 11, wherein Operating the electric drive machine in the emergency operation mode includes operating the battery when the power of the electric drive machine is reduced.

17. The method according to claim 16 further comprises starting a countdown timer based on switching the first contactor to open, and shutting off power to the electric drive motor in the electric drive machine based on the expiration of the countdown timer.

18. An electric drive system for a machine, comprising: A power distribution unit (PDU) comprising a power input device, a first switching circuit, a second switching circuit, and a non-switching circuit; The first switching circuit includes a first bus and a first contactor electrically connected between the first bus and the power input device, the second switching circuit includes a second bus and a second contactor electrically connected between the second bus and the power input device, and the non-switching circuit includes a third bus; A plurality of electric accessories, the plurality of electric accessories being arranged in a first accessory group and a second accessory group; The first accessory group includes a plurality of accessories connected in parallel to the first bus and at least one accessory connected across to the second bus, and the second accessory group includes a plurality of accessories connected in parallel to the second bus and at least one accessory connected across to the second bus; And The PDU is operable in a full power mode in which each of the first contactor and the second contactor is closed, and is adjustable to operate in an emergency operation mode in which one of the first contactor or the second contactor is closed and the other of the first contactor or the second contactor is open.

19. The electric drive system according to claim 18 further comprises a first fluid passage and a second fluid passage, and the first accessory group and the second accessory each respectively comprise at least one accessory working fluid connected to the first fluid passage and the second fluid passage; Each of the first fluid passage and the second fluid passage comprises a plurality of fluid circuits, each of the fluid circuits being configured to convey a fluid in heat transfer contact with a component different from one of the plurality of temperature-sensitive components; and The first fluid passage comprises a first manifold box shared by the respective plurality of fluid circuits, and the second fluid passage comprises a second manifold box shared by the respective plurality of fluid circuits.

20. The electric drive system according to claim 19 further comprises a first plurality of batteries temperature-controlled by the plurality of fluid circuits of the first fluid passage, and a second plurality of batteries temperature-controlled by the plurality of fluid circuits of the second fluid passage.

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