Systems and methods for operating split power distribution systems

Abstract

A working machine (100) using a DC power system (700) that isolates reactive loads is described herein. A work machine (100) uses a machine power distribution unit (712) that receives direct current power from two or more battery packs of a power unit, where each of the battery packs delivers power on a separate direct current bus. A machine power distribution unit (712) of the work machine (100) receives power from the battery and is used to isolate power using the bus connector. One of the battery packs supplies power to one DC bus of the work machine (100), and the other battery pack supplies power to the other DC bus of the work machine (100). A reactive load powered by one of the battery packs is electrically disconnected from another reactive load powered by another battery pack.

Description

Technical Field

[0001] This disclosure relates to a power distribution system used on heavy-duty machinery. More specifically, this disclosure relates to using power distribution units to change the mode of the power distribution system. Background Technology

[0002] Heavy-duty machinery, such as earthmoving vehicles or transport trucks, requires significant power to perform its functions. The machines themselves can be quite heavy, and moving their loads demands considerable power. Diesel engines have traditionally provided this power, but they can have drawbacks. However, using internal combustion engines in enclosed mining spaces presents several challenges. For example, it is necessary to efficiently remove exhaust gases from internal combustion engines from underground tunnels to maintain a favorable atmospheric environment for workers and reduce pollutant emissions to the surface and atmosphere. Furthermore, these machines are used to move large quantities of material over long distances along underground and surface transport routes. Diesel fuel supplies may be located far from these locations or difficult to deliver.

[0003] Electricity is used to supplement or replace diesel engines in these mining machines. In some environments, electricity is delivered by one or more batteries. Batteries are used to supply power to various electrical devices within the working machine. For example, batteries can power devices such as, but not limited to, electric motors for rotating the working machine's wheels, inverters for converting battery power into various other forms of electricity, electric pumps, pumps for hydraulic systems, and so on. These batteries can be charged while installed on the machine, provided there is a suitable connection and power source. In other examples, batteries can be replaced, thereby removing a discharged battery and installing a rechargeable one. Summary of the Invention

[0004] In one aspect of the currently disclosed subject matter, a DC power system for a work machine includes: a power unit comprising a first battery pack configured to output DC power on a first DC bus, and a second battery pack configured to output DC power on a second DC bus; and a machine power distribution unit comprising: a first bus connector that, when in an open configuration, electrically disconnects the first DC bus from a third DC bus, and when in a closed configuration, electrically connects the first DC bus to the third DC bus, wherein the third DC bus supplies power to a first reactive load of the work machine when the first bus connector is in the closed configuration; and a second bus connector that, when in an open configuration, electrically disconnects the second DC bus from a fourth DC bus, and when in a closed configuration, electrically connects the second DC bus to the fourth DC bus, wherein the fourth DC bus supplies power to a second reactive load of the work machine when the second bus connector is in the closed configuration.

[0005] In another aspect of the currently disclosed subject matter, a controller for a DC power system of a work machine includes a first memory storing computer-executable instructions and a first processor communicating with the memory, the computer-executable instructions causing the first processor to perform actions including placing the DC power system into an operating mode by: disconnecting a first bus connector to electrically disconnect the first DC bus from a second DC bus, thereby electrically disconnecting a first reactive load of the work machine from a second reactive load of the work machine; closing a second bus connector to electrically connect a first battery pack of a power unit to the first DC bus to provide power to the first reactive load of the work machine; and closing a third bus connector to electrically connect a second battery pack of the power unit to the second DC bus to provide DC power to the second reactive load of the work machine.

[0006] In another aspect of the currently disclosed subject matter, a DC power system includes: a power system mode in which a first bus connector is disconnected to electrically disconnect a first DC bus from a second DC bus, thereby electrically disconnecting a first reactive load of the working machine from a second reactive load of the working machine; a second bus connector is closed to electrically connect a first battery pack of a power unit to the first DC bus to provide power to the first reactive load of the working machine; and a third bus connector is closed to electrically connect a second battery pack of the power unit to the second DC bus to provide DC power to the second reactive load of the working machine; and a reduction In the reduced power mode, DC power is provided by the secondary battery, wherein in the reduced power mode, the first bus connector is closed to electrically connect the first DC bus to the second DC bus, wherein the secondary battery provides DC power to the converter, and wherein the converter provides DC power to the second DC bus, the second bus connector is opened to electrically disconnect the first battery pack from the first DC bus, and the third bus connector is opened to electrically disconnect the second battery pack from the second DC bus, wherein in the reduced power mode, the secondary battery provides DC power to the first reactive load and the second reactive load. Attached Figure Description

[0007] Figure 1 An isometric view of a working machine in an XYZ coordinate system is shown as an example suitable for implementing the principles discussed in this disclosure.

[0008] Figure 2 It is a top-down illustration of a working machine according to one or more examples of this disclosure.

[0009] Figure 3The process of installing a power unit onto a working machine according to one or more examples of this disclosure is shown.

[0010] Figure 4 This is an illustration of a lifting mechanism for mechanically engaging a power unit with a working machine, according to one or more examples of this disclosure.

[0011] Figure 5 This is a diagram illustrating the power interface of a working machine according to one or more examples of this disclosure.

[0012] Figure 6 This is a diagram illustrating a power unit interface of a power unit for electrically connecting a power unit to a working machine, according to one or more examples of this disclosure.

[0013] Figure 7 This is a diagram illustrating a direct current (DC) power system in operating mode according to one or more examples of this disclosure.

[0014] Figure 8 This is an illustration showing a DC power system in charging mode according to one or more examples of this disclosure.

[0015] Figure 9 This is a diagram illustrating a DC power system in a reduced power mode according to one or more examples of this disclosure.

[0016] Figure 10 This is an illustration of a DC power system in battery-isolated mode according to one or more examples of this disclosure.

[0017] Figure 11 A component-level view of a machine PDU for use with the systems and methods described herein is depicted, based on various examples of currently disclosed topics. Detailed Implementation

[0018] Wherever possible, the same reference numerals will be used throughout the accompanying drawings to denote the same or similar parts. Figure 1 An isometric view of a working machine 100 in an XYZ coordinate system is shown as an example suitable for implementing the principles discussed in this disclosure. The exemplary working machine 100 typically travels along a mining route from its starting point to its destination within a work site. In one embodiment shown, the working machine 100 is a transport machine that transports loads within or from the work site of an underground mining operation. For example, the working machine 100 may transport excavated ore or other earthwork materials from the excavation area to a dumping site and then back to the excavation area. In this arrangement, the working machine 100 is one of many similar machines configured to transport earthwork materials in a transport vehicle configuration.

[0019] Although in this case it is a large underground mining truck, the work machine 100 is any machine that transports loads between different locations within a work site, examples of which include articulated trucks, off-highway trucks, on-highway dump trucks, wheeled tractor-loaders, or any other similar machine. Alternatively, the work machine 100 is an off-highway truck, on-highway truck, dump truck, articulated truck, loader, excavator, pipe-laying machine, or motorized grader. In other embodiments, the work machine 100 does not need to transport a load and can be any machine associated with a variety of industrial applications, including but not limited to mining, agriculture, forestry, construction, and other industrial applications.

[0020] refer to Figure 1 An exemplary operating machine 100 includes a front section 102 and a rear section 104. In some examples, the front section 102 is movably connected to the rear section via a hinged connector, which is not shown but will be described below. Figure 2 This is illustrated in more detail below. In some examples, the front segment 102 and the rear segment 104 are independently movable on multiple axes of rotation, thereby allowing the front segment 102 to move to a certain extent independently of the rear segment 104, as shown below. Figure 7 This will be explained in more detail below. The working machine 100 also includes a cab 106. The cab 106 can be a climate-controlled interior space occupied by one or more operators of the working machine 100 during operation. The working machine also includes a bucket 108 mounted at the rear section 104 of the working machine 100. The bucket 108 serves as a volume that can hold excavated materials or other materials for transport. The bucket 108 is raised and lowered using a hydraulic piston, an example of which is shown in [example missing]. Figure 1 The piston shown is 110.

[0021] The work machine 100 also includes a power unit 112 that supplies power to the various electrical devices of the work machine 100. The power unit 112 houses one or more battery packs or battery modules (not shown), as follows: Figure 2 The following describes the process in more detail. The power unit 112 supplies power to wheel assemblies such as the front wheel assembly 114A and the rear wheel assembly 114B, where complementary wheel assemblies on the other side of the working machine 100 are not shown. Wheel assemblies 114A and 114B consist of electric motors that receive power from the power unit 112 via one or more inverters. Figure 2The following describes the process in more detail. The inverter converts the DC power supplied by the battery in power unit 112 into AC current used by the motors of wheel assemblies 114A and 114B. The polarity and power supplied by the inverter to wheel assemblies 114A and 114B cause the motors of wheel assemblies 114A and 114B to rotate, thereby rotating tires 116A and 116B, respectively. In some examples, wheel assemblies 114A and 114B receive power independently. For example, wheel assembly 114A receives power from an inverter located in front section 102, while wheel assembly 114B receives power from an inverter located in rear section 104. Additionally, wheel assemblies in one section (such as front section 102 or rear section 104) are powered independently of complementary wheel sections in the same section. In this way, each wheel assembly operates independently of the others.

[0022] In some examples, power unit 112 is unusable. For example, in some configurations of the work machine 100, power unit 112 is movable. In other examples, power unit 112 is discharged to the point that it cannot provide power at the required level. Another example is when power unit 112 is damaged or otherwise electrically disconnected from the work machine 100. In examples where power unit 112 is unusable, a secondary battery 118 is used. In some examples, secondary battery 118 is used to move the work machine 100 along a transport route by providing power to wheel assemblies 114A and 114B. In further examples, secondary battery 118 provides power to other electrical loads, such as, but not limited to, heating, cooling, and ventilation (HVAC) system 120. HVAC system 120 is used to heat or cool the air within the cab 106. In some examples, secondary battery 118 is used to supplement or enhance the power provided by power unit 112 under certain conditions, such as when power unit 112 is fully discharged and being replaced with a fully charged power unit 112. Below Figure 2 The diagram shows additional electrical and mechanical systems powered by power unit 112 and / or secondary batteries.

[0023] Figure 2This is a top-down illustration of a work machine 100 according to one or more examples of this disclosure. As described above, the work machine 100 is primarily powered by a power unit 112. The power unit 112 includes one or more batteries mechanically separated into one or more battery packs, shown as battery pack 202A and battery pack 202B. Battery pack 202A and battery pack 202B include one or more batteries, shown by way of example as batteries 204A, 204B, and 204C (hereinafter individually referred to as "battery 204A," "battery 204B," and "battery 204C," and collectively as "battery 204"). In some examples, the power unit 112 includes additional systems for monitoring and controlling the temperature of the power unit 112 and controlling various functions of the power unit not described herein. In some examples, the batteries 204 collectively provide a relatively high DC potential.

[0024] Power from power unit 112 is delivered to various devices via power interface 206. Power interface 206 includes electrical connectors for connecting power unit 112 to various systems of the operating machine 100 that are not components of power unit 112. An example of power interface 206 is shown in... Figure 6 and Figure 7 The following describes the process in more detail. An example of a device powered by power unit 112 is a device that requires a voltage lower than the voltage output of power unit 112. In these examples, a low-voltage converter 208 is provided. In some examples, low-voltage converter 208 reduces the voltage of power unit 112 to a lower voltage, such as, but not limited to, 24V. Low-voltage battery 210 is used to store the power generated by low-voltage converter 208 and acts as a battery for devices operating at lower voltages. The power provided by low-voltage converter 208 is distributed using power distribution unit 209. In some examples, power distribution unit 209 receives power from low-voltage converter 208 and distributes that power to devices operating at lower voltages. It should be noted that, as with other devices described herein, more than one low-voltage converter and low-voltage battery may be used, including those converters and batteries with voltages different from low-voltage converter 208.

[0025] The power unit 112 can also supply power to devices that use alternating current instead of direct current. In these examples, a front inverter 212A and a rear inverter 212B are provided. The front inverter 212A and the rear inverter 212B receive power from the power unit 112 and convert the direct current / voltage supplied by the power unit 112 into alternating current / voltage used by various devices. For example, such as... Figure 1 As discussed in the paper, each wheel component of the working machine is individually controllable. Figure 2 It shows Figure 1Wheel assemblies 114B and 214B are described herein. Each wheel assembly consists of an electric motor that uses AC power to rotate the shafts (not shown) of the motors in wheel assemblies 114B and 214B. A rear inverter 212B receives power from power unit 112 via a rear power cable 216 (i.e., is in electrical communication with this power unit). A front inverter 212A receives power from power unit 112 via a front power cable 217. The rear inverter 212B converts the power from power unit 112 and delivers AC power to each of wheel assemblies 114B and 214B, whereby the power delivered to each of wheel assemblies 114B and 214B can be different from each other and can be directed with respect to the wheel assemblies located in the front section 102 (e.g., [missing information]). Figure 1 The wheel assembly 114A described herein is different. Similarly, the front inverter 212A converts the power from the power unit 112 and delivers AC power to each of the wheel assemblies 114A and 214A, thus the power delivered to each of the wheel assemblies 114A and 214A can be different from each other, and can also be different with respect to the wheel assemblies (e.g., wheel assemblies 114B and 214B) located in the rear section 104. In some examples described herein, the power is a local distributed power system, with the front inverter 212A supplying power to the devices in the front section 102, and the rear inverter 212B supplying power to the devices in the rear section 104. Therefore, the power provided by the front inverter 212A and the rear inverter 212B is a local distributed power system, meaning that a component receiving power from an inverter receives power from an inverter located in the same section as the section where that component is located. Therefore, in some examples, power is supplied to the rear section 104 component using only a single power cable (i.e., rear power cable 216) from the front section 102 to the rear section 104 starting from power unit 112, instead of using individual power cables to each component.

[0026] In addition to Figure 1In addition to the low-voltage battery 210 described herein, in some examples, the secondary battery 118 is used to power devices requiring a voltage higher than that provided by the low-voltage battery 210. In examples where power unit 112 is unavailable, the secondary battery 118 is used to provide power to the front and rear wheel assemblies (e.g., wheel assemblies 114B and 214B) and wheel assemblies 114A and 214A. In examples where the secondary battery 118 is used as the main power source, power from the secondary battery 118 can be transferred to the rear inverter 212B and / or the front inverter 212A to provide AC power to components powered by the rear inverter 212B and / or the front inverter 212A. In some examples, the DC power provided by the secondary battery 118 is boosted using a converter 220 (sometimes referred to as a “buck-boost”, “buck-boost inductor”, or “buck-boost converter”). In some examples, the converter 220 is a DC-to-DC converter whose output DC voltage is greater than the input voltage. In some examples, the higher voltage output of converter 220 is received as a power input by the post-inverter 212B and / or the pre-inverter 212A to provide AC power to components powered by the post-inverter 212B and / or the pre-inverter 212A.

[0027] The working machine 100 also includes a local distributed hydraulic system that provides hydraulic power to the hydraulic equipment used by the working machine 100. Figure 2 In this configuration, the working machine includes a front hydraulic pump 222A and a rear hydraulic pump 222B. The front hydraulic pump 222A is an electric pump that receives hydraulic fluid stored in a hydraulic tank 223 via hydraulic line 225A and pressurizes the hydraulic fluid for use by the front accumulator 224A. Similarly, the rear hydraulic pump 222B is an electric pump that receives hydraulic fluid stored in a hydraulic tank 223 via hydraulic line 225B and pressurizes the hydraulic fluid for use by the rear accumulator 224B. Similar to the front inverter 212A and rear inverter 212B, the front accumulator 224A provides hydraulic pressure to the hydraulic load in the front section 102, and the rear accumulator 224B provides hydraulic pressure to the hydraulic load in the rear section 104. In some examples, hydraulic lines 225A and 225B are relatively low-pressure hydraulic lines. In this configuration, the hydraulic line from the front section 102 to the rear section 104, namely hydraulic line 225B, is a lower pressure line.

[0028] In some examples, the work machine 100 has a first configuration in which a power unit 112 is removably attached to the work machine 100. In this first configuration, the power unit 112 is charged by an external power source through a charging port 226 located on the work machine 100. Although in this first configuration the power unit 112 can be removed in certain situations (e.g., during maintenance), the power unit 112 and the work machine 100 are configured to be a single unit that is primarily combined during the use of the work machine 100. A cable (not shown) from an external power source is mechanically and electrically attached to the charging port 226. Power is then transmitted through the charging port 226 to the battery 204 of the power unit 112 to recharge the battery 204. When using the first configuration, since the power unit 112 remains electrically and mechanically connected to the work machine 100, it may not be necessary to... Figure 2 Some components described herein. For example, in the first configuration, the secondary battery 118, power interface 206, and converter 220 may not be needed or desired. However, it should be understood that one or more of the aforementioned components, as well as other unmentioned components, can still be installed regardless of the configuration of the work machine 100. The work machine 100 may also have a second configuration in which the power unit 112 is removed and replaced with a second power unit. In the second configuration, when the new power unit 112 is to be used, the work machine 100 and the power unit 112 are configured to allow the removal of the power unit 112 from the work machine 100, followed by the installation of a new, charged power unit 112 onto the work machine, which... Figure 3 and Figure 4 It is shown in more detail below.

[0029] Figure 3 The process of installing a power unit 112 onto a work machine 100 in a second configuration according to one or more examples of the present disclosure is shown. Figure 3 The diagram illustrates the disassembly mode, installation mode, and installed mode of the working machine 100 with respect to the power unit 112. In the disassembly mode, the working machine 100 is not engaged with the power unit, or is disengaged from it. Examples of the disassembly mode may include, but are not limited to, periods when the working machine 100 is being maintained and the power unit 112 is not required. Another example of the disassembly mode could be when the working machine 100 has previously disassembled the power unit and is moving to another location to receive a new power unit. The installation mode indicates that the working machine 100 is moving or has been moved to a configuration suitable for engaging and receiving the power unit 112. The installed mode indicates that the working machine 100 has received the power unit 112 and has mechanically and electrically connected the power unit 112 to the working machine 100 using the lifting mechanism and power interface 206. Figure 4 This will be shown in more detail elsewhere.

[0030] Figure 4 This is a diagram illustrating a lifting mechanism 402 for mechanically engaging the power unit 112 with the working machine 100 and a power interface 206 for electrically engaging the power unit 112 with the working machine 100, according to one or more examples of this disclosure. Figure 4 The disassembly, installation, and installed modes of the working machine 100 are shown. A lifting mechanism 402 is provided to mechanically engage the power unit 112 with the working machine 100. The lifting mechanism 402 rotates about an axis XY, which is orthogonal to the centerline AB of the working machine 100. Lifting arms 404A and 404B engage the power unit 112. When rotating about the axis XY, lifting arms 404A and 404B move in the direction Z, thereby lifting the power unit 112 off the ground and engaging it with the working machine 100. Lifting arms 404A and 404B rotate using hydraulic power or electricity. When lifting arms 404A and 404B rotate to engage the power unit 112 with the working machine 100, an electrical connection from the power unit is provided through an electrical interface 206 located on the working machine 100. Figure 5 A more detailed description is provided below.

[0031] Figure 5 This is an illustration of a power interface 206 of a work machine 100 according to one or more examples of this disclosure. The power interface 206 includes male connectors 502A and 502B. Male connectors 502A and 502B extend outward from the work machine 100 to engage with a complementary female connector, which in... Figure 6 As shown in the diagram. The power interface 206 also includes alignment pins 504A and 504B, which also extend outward from the working machine 100 by a distance and are aligned with... Figure 6 The complementary female alignment holes shown are engaged. Alignment pins 504A and 504B act as indicators for indicating when the power unit 112 is raised to... Figure 3 and 4In the installation mode, they are correctly aligned and positioned on the work machine 100. Male connectors 502A and 502B are electrically connected to various systems and are designed to receive various electrical inputs. For example, power connector 506A is configured to receive power from battery pack 202A, and power connector 506B is configured to receive power from battery pack 202B. In some configurations, battery packs 202A and 202B are electrically connected such that power from both battery packs 202A and 202B is provided through a single positive terminal and a single negative terminal. Therefore, in this configuration, power connector 506A is configured to receive power from the positive terminals of battery packs 202A and 202B, and power connector 506B is configured to connect to the negative terminals or ground terminal of battery packs 202A and 202B. Male connectors 502A and 502B can provide electrical connections for other electrical signals, such as data, communication systems, additional power systems, sensors, etc.

[0032] Figure 6 This is an illustration of a power unit interface 602 of a power unit 112 according to one or more examples of this disclosure, the power unit interface for electrically connecting the power unit 112 to a working machine 100. The power unit interface 602 includes female recesses 604A and 604B. The female recesses 604A and 604B extend into the working machine 100 to receive complementary male connectors 502A and 502B of a power interface 206, the complementary male connectors being inserted into the complementary female recesses 604A and 604B. The power unit interface 602 also includes alignment recesses 606A and 606B for receiving alignment pins 504A and 504B. A female power connector 608A receives a power connector 506A and a female power connector 608B receives a power connector 508B for distribution to various systems, including locally distributed systems such as wheel assemblies 114A, 114B, 214A, and 214B.

[0033] Because in some examples, the work machine 100 uses a local distributed power system, this means that the work machine 100 has more than one power component powered by DC power, and therefore, DC current oscillations may occur due to the interaction of these power components. DC current oscillations may also occur when the power component consists of reactive components such as inductors and capacitors, thereby generating AC current within the DC power system. The reactive power components of the work machine may include a front inverter 212A and a rear inverter 212B. As described above, a portion of the DC power system of the work machine 100 supplies power to various loads. For example, a portion of the DC power received from power unit 112 at the rear inverter 212B is received via the rear power cable 216. Similarly, a portion of the DC power received from power unit 112 at the front inverter 212A is received via the front power cable 217. However, it should be understood that the subject matter disclosed herein is not limited to inverters, as other reactive components used on the work machine 100 may also cause DC current oscillations. The local distributed power system of the operating machine 100 is configured to provide power to multiple reactive loads supplied by power unit 112, as described below. Figure 7-9 A more detailed description is provided below.

[0034] Figure 7 This is a diagram illustrating a direct current (DC) power system 700 in operating mode, according to one or more examples of the currently disclosed subject matter. Figure 7 The diagram shows the power unit 112, front section 102, and rear section 104 of the working machine 100. It should be noted that although the DC power system 700 of the working machine 100 is shown distributed across multiple sections of the working machine 100 (i.e., front section 102 and rear section 104), the subject matter disclosed herein is not limited to implementation in multiple sections on the working machine 100. Return Figure 7 The power unit 112 supplies DC power from battery pack 202A to the working machine 100 via DC bus 702, and DC power from battery pack 202B to the working machine 100 via DC bus 704. DC buses 702 and 704 feed into the power unit distribution unit (PDU) 706. The power unit PDU 706 is configured to receive power from the controller (…). Figure 11 (As described in the text) Receives control input, and the controller disconnects and closes bus connectors 708 and 710. In the disconnected configuration, bus connector 708 electrically disconnects battery pack 202A from DC power system 700, and in the closed configuration, bus connector 708 electrically connects battery pack 202A to DC power system 700. Similarly, in the disconnected configuration, bus connector 710 electrically disconnects battery pack 202B from DC power system 700, and in the closed configuration, bus connector 710 electrically connects battery pack 202B to DC power system 700.

[0035] Power from DC bus 702 and DC bus 704 is received into machine power distribution unit (PDU) 712 via power unit interface 602 and power interface 206. Machine PDU 712 is configured to receive power from the controller (in... Figure 11 (Using controller 1100 as an example) It receives control input to place bus connectors 714, 716, 718, and 720 in an open or closed configuration. These bus connectors are switches that allow machine PDU 712 to open and close, configuring DC power system 700 for various purposes, as discussed in more detail below. Power from machine PDU 712 is distributed to DC bus 722 and DC bus 724. DC bus 722 supplies power to front inverter 212A and rear inverter 212B. Front inverter 212A and rear inverter 212B convert the DC power received by machine PDU 712 and convert it to alternating current (AC) power for use by various loads that use AC power. For example, front inverter 212A supplies AC power to front traction motor 734A and front traction motor 734B. The front traction motor 734A is the motor for wheel assembly 114A, and the front traction motor 734B is the motor for wheel assembly 214B. The front inverter 212A also supplies AC power to the front hydraulic pump 222A, which, as described above, is an electric pump that receives hydraulic fluid stored in hydraulic tank 223 via hydraulic line 225A and pressurizes the hydraulic fluid for use by the front accumulator 224A. The DC bus 722 also provides power to charge the low-voltage battery 210.

[0036] The rear inverter 212B supplies AC power to the rear traction motors 734C and 734D. The rear traction motor 734C is the motor for wheel assembly 114A, and the rear traction motor 734D is the motor for wheel assembly 214A. The rear inverter 212B also supplies AC power to the rear hydraulic pump 222B, which, as described above, is an electric pump that receives hydraulic fluid stored in hydraulic tank 223 via hydraulic line 225B and pressurizes the hydraulic fluid for use by the rear accumulator 224B. The low-voltage battery 740 can be charged with DC power via DC bus 724. The rear inverter 212B also communicates electrically with converter 220. Converter 220 receives power from secondary battery 118 and outputs a DC voltage greater than the input voltage of secondary battery 118. As described above, if power unit 112 is unavailable, power from converter 220 can be used to power post-inverter 212B, thereby providing AC power when power unit 112 is unavailable. It should be understood that... Figure 7The electrical loads described and shown are merely examples and are not intended to limit the scope of the subject matter currently disclosed. For example, a DC power system 700 may include more than two inverters, different types of reactive loads, etc.

[0037] The configuration of the DC power system 700 established by machine PDU 712 is an operating mode. In this operating mode, bus connectors 714 and 716 are closed (meaning current is allowed to flow through these bus connectors), and bus connectors 718 and 720 are closed (meaning current is not allowed to flow through these bus connectors). In this operating mode, bus connector 720 is open, electrically disconnecting the DC power system 700 from the external power supply 728 that can be used to charge battery packs 202A and / or 202B. As shown, battery pack 202A is electrically in communication with and powered by DC bus 722. Additionally, battery pack 202B is electrically in communication with and powered by DC bus 724. In this operating mode, as shown, the DC power system 700 is isolated, thereby preventing the load on battery pack 202A from electrically communicating with the load on battery pack 202B. Therefore, the reactive load of the front inverter 212A does not affect or interact with the reactive load of the rear inverter 212B. Thus, in this operating mode, resonant circuits between the front inverter 212A and the rear inverter 212B are prevented. This operating mode is typically used when the work machine 100 is operated and the power unit 112 is available. However, in some examples, battery packs 202A and / or 202B may require charging. In this example, the DC power system 700 can be configured for charging mode.

[0038] Figure 8This is an illustration of a DC power system 700 in charging mode according to one or more examples of the currently disclosed subject matter. In charging mode, bus connectors 714, 716, 718, and 720 are closed (meaning current is allowed to flow through these bus connectors). As shown, battery packs 202A and 202B are in electrical communication with and receive power from an external power source 728 via charging bus 726. Power from the external power source 728 enters the machine PDU 712 via bus connector 720. Power from the external power source 728 is then directed to the power unit PDU 706 via power unit interface 602 and power interface 206. Power received by battery pack 202A via DC bus 702 charges battery pack 202A. Power received by battery pack 202A via DC bus 702 charges battery pack 202B. It should be understood that the currently disclosed subject matter is not limited to simultaneous charging of both battery packs 202A and 202B, as each battery pack can be charged individually. For example, bus connector 718 and / or bus connector 714 can be disconnected, thereby electrically disconnecting battery pack 202A from external power source 728. In some cases, power from external power source 728 may not be able to charge battery pack 202A and / or battery pack 202B. For example, the operating machine 100 may be located at a location on a transport route where external power source 728 is unavailable. In this example, DC power system 700 can be configured to a reduced power mode, which... Figure 9 As shown in the image.

[0039] Figure 9This is an illustration of a DC power system 700 in a reduced power mode, according to one or more examples of the currently disclosed subject matter. In the reduced power mode, DC power from the secondary battery 118 is used to power the rear inverter 212B. Therefore, in this configuration, the rear inverter 212B still generates AC power for some loads (e.g., the rear traction motors 734C and 734B), thereby allowing the work machine 100 to have at least partial mobility. In another configuration, the DC power from the secondary battery 118 is used, either in conjunction with or in lieu of powering the rear inverter 212B, to power the front inverter 212A. In a configuration where the front inverter 212A receives power from the secondary battery 118, the front inverter 212A can power the front traction motors 734A and / or 734B. In some configurations, the power supplied to the front inverter 212A may be AC ​​power from the rear inverter 212B, or DC power transferred from the rear inverter 212B to the front inverter 212A. If AC power is supplied from the rear inverter 212B, the front inverter 212A is not used, and the AC power from the rear inverter 212B is directed through the front inverter 212A to loads typically powered by the front inverter 212A. If no AC power is supplied from the rear inverter 212B, meaning that DC power from the secondary battery 118 is supplied to the front inverter 212A, the front inverter 212A receives the DC power and converts it into AC power to power one or more loads typically powered by the front inverter 212A.

[0040] In some examples where DC power from secondary battery 118 is supplied to front inverter 212A, rear inverter 212B may not be used. Therefore, the reduced power mode can have at least three configurations. In a first configuration, both rear inverter 212B and front inverter 212A receive DC power from the battery and use it to generate AC power for their respective loads. In a second configuration, rear inverter 212B generates AC power, and front inverter 212A does not generate DC power. In this second configuration, rear inverter 212B can be used to power loads that are normally powered by front inverter 212A. In a third configuration, rear inverter 212B does not generate AC power, and front inverter 212A generates DC power from the DC power supplied by secondary battery 118. In this third configuration, front inverter 212A can be used to power loads that are normally powered by rear inverter 212B. In the reduced power mode, bus connectors 714, 716, and 720 are disconnected, and bus connector 718 is closed. In the reduced power mode, when power unit 112 is unavailable, the rear inverter 212B and / or the front inverter 212A can be used to supply power to various loads of the DC power system 700. However, in some examples, one battery pack in the battery bank of power unit 112 remains available, rather than being completely unavailable. In this example, the DC power system 700 can be configured in a battery bank isolation mode, which... Figure 10 As shown in the image.

[0041] Figure 10 This is an illustration of a DC power system 700 in battery pack isolation mode, according to one or more examples of the currently disclosed subject matter. In battery pack isolation mode, one battery pack of the power unit 112 is unusable and electrically disconnected from the DC power system 700. An exemplary case of using battery pack isolation mode could be when a fault (e.g., a short circuit) on DC bus 702 requires the battery pack 202A to be electrically disconnected from the DC power system 700. In this example, bus connectors 714 and 720 are disconnected, and bus connectors 716 and 718 are closed. Additionally, bus connector 708 is closed. In this configuration, battery pack 202A is electrically isolated from the DC power system, thereby allowing battery pack 202B to supply DC power to the DC power system 700. The DC power from battery pack 202B is electrically communicated with the downstream inverter 212B via bus connector 716 and with the upstream inverter 212A via bus connector 718. It should be understood that the battery pack isolation mode may also include a configuration in which only the inverter 212B receives power by disconnecting the bus connector 718.

[0042] Figure 11A component-level view of a controller 1100 for providing control inputs to a machine PDU 712 and / or a power unit PDU 706 for use with the systems and methods described herein is depicted, according to various examples of the currently disclosed subject matter. The controller 1100 can be any means capable of providing the functionality associated with the systems and methods described herein. The controller 1100 may include several components to perform the aforementioned functions. The controller 1100 may consist of hardware, software, or various combinations thereof. As discussed below, the controller 1100 may include a memory 1102, which includes an operating system (OS) 1104 and one or more standard application programs 106.

[0043] The controller 1100 may also include one or more processors 1110 and one or more of a removable storage device 1112, a non-removable storage device 1114, a plurality of transceivers 1116, a plurality of output devices 1118, and a plurality of input devices 1120. In various embodiments, the memory 1102 may be volatile (such as random access memory (RAM)), non-volatile (such as read-only memory (ROM), flash memory, etc.), or some combination of both. The memory 1102 may be stored on a remote server or server cloud accessible to the controller 1100.

[0044] The memory 1102 may also include an operating system 1104. The operating system 1104 varies depending on the manufacturer of the controller 1100. The operating system 1104 contains modules and software that support the basic functions of the controller 1100, such as scheduling tasks, executing applications, and controlling peripheral devices. The operating system 1104 may also enable the controller 1100 to send and retrieve other data and perform other functions, such as transmitting control signals using transceiver 1116 and / or output device 1118 to open and close bus connectors 714, 716, 718, and 720, and receiving signals using input device 1120.

[0045] The controller 1100 may also include one or more processors 1110. In some embodiments, the processors 1110 may be one or more central processing units (CPUs), graphics processing units (GPUs), both CPUs and GPUs, or any other combination and number of processing units. The controller 1100 may also include additional data storage devices (removable and / or non-removable), such as, for example, disks, optical discs, or magnetic tapes. Such additional storage devices... Figure 11 The image is shown by a removable storage device 1112 and a non-removable storage device 1114.

[0046] Non-transitory computer-readable media can include volatile and non-volatile, removable and non-removable tangible physical media implemented with technologies used for storing information such as computer-readable instructions, data structures, program modules or other data. Memory 1102, removable storage device 1112 and non-removable storage device 1114 are examples of non-transitory computer-readable media. Non-transitory computer-readable media include, but are not limited to, RAM, ROM, electrically erasable programmable ROM (EEPROM), flash memory or other memory technologies, optical disc ROM (CD-ROM), digital universal disc (DVD) or other optical storage devices, magnetic tape cassettes, magnetic tape, disk storage devices or other magnetic storage devices, or any other tangible physical media that can be used to store desired information and is accessible by controller 1100. Any such non-transitory computer-readable media may be part of controller 1100 or may be a separate database, data bank, remote server or cloud-based server.

[0047] In some implementations, transceiver(s) 1116 includes any transceiver known in the art. In some examples, transceiver(s) 1116 may include multiple wireless modems to facilitate wireless connectivity with other components (e.g., between controller 1100 and a wireless modem serving as a gateway to the Internet), the Internet, and / or intranets. Specifically, transceiver(s) 1116 may include one or more transceivers that enable controller 1100 to send and receive data. Thus, transceiver(s) 1116 may include multiple single-channel transceivers or multi-frequency multi-channel transceivers to enable controller 1100 to send and receive video calls, audio calls, messaging, etc. Transceiver(s) 1116 may enable controller 1100 to connect to multiple networks, including but not limited to 2G, 3G, 4G, 5G, and Wi-Fi networks. (Multiple) transceivers 1116 may also include one or more transceivers to enable controller 1100 to connect to future (e.g., 6G) networks, Internet of Things (IoT), machine-to-machine (M2M) networks, and other current and future networks.

[0048] (Multiple) transceivers 1116 may also include functions that can be performed via an antenna (e.g., Wi-Fi or Bluetooth). ® One or more radio transceivers are configured to transmit and receive radio frequency communications. In other examples, transceivers 1116 may include wired communication components, such as wired modems or Ethernet ports, for communicating via one or more wired networks. Transceivers 1116 may enable controller 1100 to facilitate audio and video calls, file downloads, access to network applications, and other communications associated with the systems and methods described above.

[0049] In some embodiments, the output device(s) 1118 includes any output device known in the art, such as a display (e.g., a liquid crystal or thin-film transistor (TFT) display), a touchscreen, a speaker, a vibration mechanism, or a haptic feedback mechanism. Therefore, the output device(s) 1118 may include a screen or display. The output device(s) 1118 may also include a speaker or similar device to play sound or a ringtone upon receiving an audio or video call. The output device(s) 1118 may also include ports for one or more peripheral devices, such as headphones, peripheral speakers, or peripheral displays.

[0050] In various embodiments, the input device(s) 1120 includes any input device known in the art. For example, the input device(s) 1120 may include a camera, microphone, or keyboard / keyboard. The input device(s) 1120 may include a touch-sensitive display or keyboard to enable a user to input data and make requests and receive responses via a web application (e.g., in a web browser), make audio and video calls, and use standard application 406, etc. The touch-sensitive display or keyboard / keyboard may be a standard button alphanumeric keypad (such as a conventional QWERTY keyboard), virtual controls on a touchscreen, or one or more other types of keys or buttons, and may also include joysticks, wheels, and / or designated navigation buttons, etc. The touch-sensitive display may function as both input device 1120 and output device 1118.

[0051] Industrial applicability

[0052] The work machine 100 described herein uses a DC power system 700, which reduces the probability of reactive loads on power unit 112 generating oscillating circuits by isolating one or more reactive loads from other reactive loads. If not isolated to different DC buses, reactive loads (e.g., front inverter 212A and rear inverter 212B) can interact with each other and form a system capable of oscillation. Oscillation is a condition in which alternating current / voltage is generated through the interaction of these reactive loads. Alternating current / voltage can damage electrical equipment configured to receive only DC power. In some cases, the damage can be severe enough to pose a safety hazard to personnel and equipment. Although electrical devices may exist capable of suppressing the amplitude of oscillations, these devices often act as parasitic loads, thereby shortening battery life by depleting the battery faster than without these devices. In the electric work machine 100, the parasitic load on the dampers can reduce the usable time of the work machine 100.

[0053] The DC power system 700 uses the separated battery packs 202A and 202B of power unit 112 to provide isolation, rather than using parasitic loads to suppress oscillations. Therefore, oscillating currents are not generated by the interaction between the front inverter 212A and the rear inverter 212B, because these inverters are on separate DC power buses. However, in some cases, placing inverters 212A and 212B on separate DC buses may be impractical or undesirable. In other cases, power unit 112 may not be usable. Therefore, in these cases, the DC power system 700 uses machine PDU 712 to electrically connect the front inverter 212A and the rear inverter 212B using bus connectors. Thus, the DC power system 700 can reduce oscillations by isolating reactive loads such as those of the rear inverter 212B and the front inverter 212A from each other, while providing the flexibility to connect components where electrical connections are required.

[0054] Unless explicitly excluded, the use of the singular to describe a component, structure, or operation does not preclude the use of multiple such components, structures, or operations or their equivalents. As used herein, the word “or” refers to any possible permutation of a set of items. For example, the phrase “A, B, or C” refers to at least one of A, B, C, or any combination thereof, such as any one of the following: A; B; C; A and B; A and C; B and C; A, B, and C; or multiple items such as A and A; B, B, and C; A, A, B, C, and C, etc.

[0055] While aspects of this disclosure have been specifically shown and described with reference to the foregoing embodiments, those skilled in the art will understand that various other embodiments can be conceived through modifications to the disclosed machines, systems, and methods without departing from the spirit and scope of the disclosure. Such embodiments should be understood to fall within the scope of this disclosure as defined by the claims and any equivalents.

Claims

1. A DC power system (700) for a work machine (100), comprising: Power unit, the power unit comprising: The first battery pack (202A) is configured to output DC power on the first DC bus (702); A second battery pack (202B) is configured to output DC power on a second DC bus (704); and Machine power distribution unit (712), the machine power distribution unit includes: A first bus connector (714) electrically disconnects the first DC bus (702) from the third DC bus (722) when in an open configuration, and electrically connects the first DC bus (702) to the third DC bus (722) when in a closed configuration, wherein the third DC bus (722) supplies power to the first reactive load of the machine (100) when the first bus connector (714) is in the closed configuration; and The second bus connector (716) electrically disconnects the second DC bus (704) from the fourth DC bus (724) when in the open configuration, and electrically connects the second DC bus (704) to the fourth DC bus (724) when in the closed configuration, wherein the fourth DC bus (724) supplies power to the second reactive load of the working machine (100) when the second bus connector (716) is in the closed configuration.

2. The DC power system (700) of the working machine (100) according to claim 1, wherein the machine power distribution unit (712) and the first reactive load are installed on the front section (102) of the working machine (100), and the second reactive load is installed on the rear section (104) of the working machine (100).

3. The DC power system (700) for the work machine (100) according to claim 2, wherein the first reactive load includes a first inverter (212A) configured to provide AC power to a first plurality of devices installed on the front section (102) of the work machine (100), and the second reactive load includes a second inverter configured to provide AC power to a second plurality of devices installed on the rear section (104) of the work machine (100).

4. The DC power system (700) of the working machine (100) according to claim 3, wherein the first plurality of devices installed on the front section (102) of the working machine (100) include a first traction motor (734A) and a second traction motor (734B).

5. The DC power system (700) for the working machine (100) according to claim 4, wherein the first plurality of devices installed on the front section (102) of the working machine (100) further includes a front hydraulic pump (222A) configured to pressurize hydraulic fluid in a front accumulator.

6. The DC power system (700) of the working machine (100) according to claim 3, wherein the second plurality of devices installed on the rear section (104) of the working machine (100) includes a third traction motor (734C) and a fourth traction motor (734D).

7. The DC power system (700) of the working machine (100) according to claim 6, wherein the second plurality of devices installed on the rear section (104) of the working machine (100) further includes a rear hydraulic pump (222B) configured to pressurize hydraulic fluid in a rear accumulator.

8. The DC power system (700) of the working machine (100) according to claim 3, wherein the second plurality of devices installed on the rear section (104) of the working machine (100) further includes a secondary battery, wherein the secondary battery is configured to provide DC power to the second plurality of devices installed on the rear section (104) of the working machine (100) via a converter when the power unit does not provide DC power.

9. A DC power system (700), comprising: Power system mode, wherein in the power system mode: The first bus connector (714) is disconnected to electrically disconnect the first DC bus (702) from the second DC bus (704), thereby electrically disconnecting the first reactive load of the work machine (100) from the second reactive load of the work machine (100); The second bus connector (716) is closed to electrically connect the first battery pack (202A) of the power unit to the first DC bus (702) to provide power to the first reactive load of the working machine (100); and The third bus connector is closed to electrically connect the second battery pack (202B) of the power unit to the second DC bus (704) to provide DC power to the second reactive load of the working machine (100); and In the reduced power mode, DC power is provided by the current-stage battery, wherein in the reduced power mode: The first bus connector (714) is closed to electrically connect the first DC bus (702) to the second DC bus (704), wherein the secondary battery provides DC power to the converter, and wherein the converter provides DC power to the second DC bus (704); The second bus connector (716) is disconnected to electrically disconnect the first battery pack (202A) from the first DC bus (702); and The third bus connector is disconnected to electrically disconnect the second battery pack (202B) from the second DC bus (704), wherein in the reduced power mode, the secondary battery provides DC power to the first reactive load and the second reactive load.

10. The DC power system (700) according to claim 9 further includes a charging mode for charging the first battery pack (202A) and the second battery pack (202B) using an external power source, wherein in the charging mode: The first bus connector (714) is closed to electrically connect the first DC bus (702) to the second DC bus (704). The second bus connector (716) closes to electrically connect the first battery pack (202A) of the power unit to the first DC bus (702) to provide power from the external power source to the first battery pack (202A); and The third bus connector is closed to electrically connect the second battery pack (202B) of the power unit to the second DC bus (704) to provide power from the external power source to the first battery pack (202A).

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