Dynamic charging system with independent chargers

Abstract

Systems and methods of auto-configuring a charger device for providing power from a grid system to a non-road battery electric machine (BEM) can comprise receiving an instruction, by the charger device, from a charge dispenser or a BEM to prepare for a charging operation in a designated mode, auto-configuring, by the charger device, to operate in the designated mode, auto-detecting, by the charger device, a connected state in which the charger device is connected to the charge dispenser and the grid system by performing a charger fault detection procedure, issuing a signal to perform a corrective action for a fault state if the connected state is detected to be faulty, and entering, by the charger device, a charging state in which the charger device provides power to the charge dispenser if the connected state is detected to be not faulty.

Description

[0001]Description DYNAMIC CHARGING SYSTEM WITH INDEPENDENT CHARGERS Technical Field This document relates to electric powered work machines and in particular to a Megawatt class charge dispenser system for charging the energy source of battery electric machines. Background Powering a large moving work machine (e.g., a wheel loader, a mining truck, etc.) with one or more electric motors requires a large mobile electric energy source that can provide current of thousands of Amperes (Amps). An example of a mobile energy source is a battery system containing multiple strings of high-capacity batteries. The batteries in each string are connected in series, and the strings of batteries are connected in parallel to provide the high output power needed by the electric work machines. The mobile energy source needs to be recharged when the energy source nears depletion. Different battery electric machines may have different power needs and charging needs. the Invention Electric powered large moving work machines use large capacity battery systems that need charging, and it is desirable to provide the charging at a remote job site. However, the machines at the job site may have different charging needs. It would be advantageous for a single charging system to meet the different charging needs of the different types of machines. An example charging system includes a charge dispenser and multiple chargers. The system is modular in that multiple chargers can be connected to the one dispenser to provide flexibility in meeting the charging needs at the job site. Each charger of the multiple chargers connected to the one dispenser can be configured to auto-configure itself for different operating modes, e.g., standalone charge or parallel charge, and for different grid conditions, e.g., stressed power grid and un-stressed power grid. The modular chargers of the present disclosure can form a scalable architecture on a skid / parallel to meet the demand of battery electric machine (BEM) and sight limitations. Each charger can function independently as a standalone unit when connected to the BEM for slow charging. But when the BEM require fast and maximum power charging, the individual chargers are connected in parallel to a single output (dispenser) and communicate through a series ethernet connection to the dispenser. The charger can auto-configure itself to be an independent / standalone or a skid / parallel charger upon detecting communication data with the dispenser. Whenever a skid / parallel charger is detected to be faulted and cannot or will not perform a charge cycle, it can be replaced with a functional independent or standalone charger without manual configuration. The replacement charger will auto-configure through ethernet data communication during initial powerup and during the start of every charge cycle to the type of charger configuration. Whenever the charger is directly connected to the BEM or paralleled on a skid, it can perform the procedures discussed herein. In an example, a modular charging system for charging a battery electric machine (BEM) comprises a dispenser device for connecting to the BEM and delivering a charge to the BEM and a first modular charger device to provide the charge for the dispenser device from a power grid. The first modular charger device can comprise a network connector for communicating with the dispenser device, a power input connector for connecting to the power grid, a power output connector for connecting to the dispenser device, and a charger controller. The charger controller can be configured to: receive an instruction from the dispenser device or the BEM to operate in a mode comprising a standalone mode or a parallel mode, auto-configure the first modular charger device for operation in the mode received in the instruction, and check for a charger input problem. Checking for the charger input problem can comprise allowing the power output connector to output power form the power grid if a charger input problem is not detected, and provide a communication signal to the dispenser device or the BEM for performing a charger corrective action if a charger input problem is detected. In another example, methods of auto-configuring a charger device for providing power from a grid system to a non-road battery electric machine (BEM) can comprise receiving an instruction, by the charger device, from a charge dispenser or a BEM to prepare for a charging operation in a designated mode, auto- configuring, by the charger device, to operate in the designated mode, auto- detecting, by the charger device, a connected state in which the charger device is connected to the charge dispenser and the grid system by performing a charger fault detection procedure, issuing a signal to perform a corrective action for a fault state if the connected state is detected to be faulty, and entering, by the charger device, a charging state in which the charger device provides power to the charge dispenser if the connected state is detected to be not faulty. of the 1 is an elevation view depicting an example work machine in accordance with this disclosure. FIG. 2 is a diagram of an example charging system for battery electric machines in accordance with this disclosure. FIG. 3 is a block diagram of an example of portions of a charge dispenser in accordance with this disclosure. FIG. 4 is a diagram of an example of communication networks for charger devices and a charge dispenser of a charging system in accordance with this disclosure. FIG. 5 is an example of a state diagram of operation of a charge dispenser in accordance with this disclosure. FIG. 6 is a flow diagram of an example of a method of operating a charge dispenser in accordance with this disclosure. FIG. 7 is a line diagram of an example method of auto-configuring a charger device in different charging modes and under different grid conditions to charge a battery electric machine. FIG. 8 is an example of a state diagram of operation of a charger device in accordance with a charger default detection procedure of the present disclosure. FIG.9 is a line diagram of an example method of derating output of a charging device of the present disclosure to, for example, alleviate grid stress. Detailed Description Examples according to this disclosure are directed to methods and devices that improve charging of a rechargeable energy source of an electric work machine. FIG. 1 depicts an example machine 100 in accordance with this disclosure. In FIG. 1, machine 100 includes frame 102, wheels 104, implement 106, and a speed control system implemented in one or more on-board electronic devices like, for example, an electronic control unit or ECU. Example machine 100 is a wheel loader. In other examples, however, the machine may be other types of machines related to various industries, including, as examples, construction, agriculture, forestry, transportation, material handling, waste management, marine, stationary power, and so on. Accordingly, although some examples are described with reference to a wheel loader machine, examples according to this disclosure are also applicable to other types of machines including graders, scrapers, dozers, excavators, compactors, material haulers like dump trucks, marine vessels, locomotives, along with other example machine types. Machine 100 includes frame 102 mounted on four of wheels 104, although, in other examples, the machine could have more than four wheels. Frame 102 is configured to support and / or mount one or more components of machine 100. For example, machine 100 includes enclosure 108 coupled to frame 102. Enclosure 108 can house, among other components, an electric motor to propel the machine over various terrain via wheels 104. In some examples, multiple electric motors are included in multiple enclosures at multiple locations of the machine 100. Machine 100 includes implement 106 coupled to the frame 102 through linkage assembly 110, which is configured to be actuated to articulate bucket 112 of implement 106. Bucket 112 of implement 106 may be configured to transfer material such as, soil or debris, from one location to another. Linkage assembly 110 can include one or more of cylinders 114 configured to be actuated hydraulically or pneumatically, for example, to articulate bucket 112. For example, linkage assembly 110 can be actuated by cylinders 114 to raise and lower and / or rotate bucket 112 relative to frame 102 of machine 100. Platform 116 is coupled to frame 102 and provides access to various locations on machine 100 for operational and / or maintenance purposes. Machine 100 also includes an operator cabin 118, which can be open or enclosed and may be accessed via platform 116. Operator cabin 118 may include one or more control devices (not shown) such as, a joystick, a steering wheel, pedals, levers, buttons, switches, among other examples. The control devices are configured to enable the operator to control machine 100 and / or the implement 106. Operator cabin 118 may also include an operator interface such as, a display device, a sound source, a light source, or a combination thereof. Machine 100 can be used in a variety of industrial, construction, commercial or other applications. Machine 100 can be operated by an operator in operator cabin 118. The operator can, for example, drive machine 100 to and from various locations on a work site and can also pick up and deposit loads of material using bucket 112 of implement 106. By further way of example, both operation by a remotely located operator and autonomous or robotic operation are contemplated. Machine 100 can be used to excavate a portion of a work site by actuating cylinders 114 to articulate bucket 112 via linkage assembly 110 to dig into and remove dirt, rock, sand, etc. from a portion of the work site and deposit this load in another location. Machine 100 can include a battery compartment connected to frame 102 and including a battery system 120. Battery system 120 is electrically coupled to the one or more electric motors of machine 100, which can comprise a battery electric machine (BEM). The battery system of different types of battery electric machines (BEMs) machines may have different charging needs. The battery system may differ in the amount of charge needed to fully charge the battery system, the rate at which the battery system can be charged, etc. FIG. 2 is a diagram of an example of a charging system 200 for machine 100. The charging system 200 includes multiple charger devices 226. Each charger device 226 is configured to provide high-capacity charge energy for charging machine 100. Each of the charger devices 226 can be coupled to one or more of switch devices 228 that connect the charger device to a grid, a generator set device, etc. The charging system 200 also includes one or more of charge dispenser 230. Multiple charger devices 226 are connected to a single one of charge dispenser 230. The example system of FIG. 2 includes two charge dispensers and one to six charger devices 226 that are connected to a single one of charge dispenser 230 in the example. When charging, a charge dispenser 230 is connected to machine 100 by a charging cable 232 and plug. The charging cable 232 may be air-cooled or liquid-cooled depending on the capacity of the charging cable 232. A charge dispenser 230 aggregates the charging energy from the charger devices 226 connected to it to provide the aggregated charging energy to machine 100 through the charging cable 232. This makes the charging system 200 modular and charging energy from one to six charger devices 226 can be aggregated in the example system of FIG. 2. In some examples, more than six charger devices 226 can be connected to one of charge dispenser 230 and the charge from more than six charger devices can be aggregated by the charge dispenser 230. The machines100 being charged may be automated and may operate without a human operator. Operation of the BEMs may be through a fleet management unit 234. The fleet management unit 234 may be implemented through one or more servers located at the remote site, or through one or more servers that are cloud-based. The fleet management unit 234 manages the displacements of the automated BEMs at the job site. The fleet management unit 234 may include a fleet controller 236 to communicate with the machine 100 and charge dispenser 230 wirelessly (e.g., wireless WiFi). The fleet management unit 234 sends specific instructions to the BEMs to move them on specific lanes across the job site. When the fleet management unit 234 determines that a BEM needs charging, the fleet management unit 234 may match a BEM to a charge dispenser 230 based on the charge dispenser’s location, availability, and capacity. The charging system 200 may include a robotic connector system 238. The robotic connector system 238 connects and disconnects the charging cable 232 from the receptacle of the machine 100 in response to commands. The fleet management unit 234 informs the charge dispenser 230 of the arrival of machine 100. When the machine 100 is ready to be charged, the charge dispenser 230 requests the robotic connector system 238 to connect the charging cable 232 to the machine 100. Upon connection, the charge dispenser 230 will automatically start a charging session. On completion, the charge dispenser 230 will request the robotic connector system 238 to disconnect the charging cable 232 and move back to stow position. The charge dispenser 230 may then inform the fleet management unit 234 that machine 100 can leave. All these operations can be executed without the help of a human operator on site. As discussed herein, fleet management unit 234 can provide an instruction to charge dispenser 230 for charging a specific machine 100. Charge dispenser 230 can convey some or all of the instructions to one or more charger devices 226. For example, as discussed with reference to FIG. 7, charge dispenser 230 can instruct a single charger device 226 that it will be operating in a standalone mode or can instruct multiple instances of charger device 226 that they will be operating in a parallel mode. Standalone operating instructions can alternatively be provided by direct coupling of charger device 226 to a CIC of machine 100 without the use of charge dispenser 230. Each charger device 226 that receives an instruction can auto-configure itself for the particular operating mode that it has been instructed to operate in and for a particular type of machine 100 to be charged. Additionally, each charger device 226 that has received an instruction can perform an automatic charger default detection procedure, as discussed with reference to FIG.8, to determine if any fault conditions exist or were detected that would result in charge dispenser 230 benefiting from a substitute or replacement charger device being used instead of the charger device that has a fault. Furthermore, each charger device 226 that has received an instruction can perform a grid analysis to determine if derated power should be provided to machine 100 in lieu of what has been requested by charge dispenser 230 to alleviate grid stress, e.g., high demand, on the power grid, as is discussed with reference to FIG. 9. FIG. 3 is a block diagram of an example of portions of a charge dispenser 230. The charge dispenser 230 includes one or more of charger input receptacles 340 to receive electrical energy from multiple charger devices 226. Each of the charger devices 226 can provide energy to charge machine 100. The charger devices can include power converters to produce the charge energy. The charger devices 226 are connected to the charger input receptacles 340 by charger cables 348. The charge dispenser 230 may send commands to the charger devices 226 to set the output of the power converters to a voltage and current appropriate for the type of machine 100 being charged. The charge dispenser 230 includes a cable output connector 342 to connect to a charging cable 232 that is connectable to machine 100. The charge dispenser 230 can include a dispenser bus 344 that provides accumulated charger energy to the cable output connector 342. The charge dispenser 230 also includes a dispenser controller 346 and the charger devices 226 each include a charger controller 350. A controller includes processing circuitry that includes one or more processors (e.g., microprocessors, digital signal processors (DSP), application specific integrated circuits (ASICs), a programmable gate arrays (PGAs), or equivalent discrete or integrated logic circuitry. A controller can include memory to store instructions performable by the processing circuitry. The instructions may be software or firmware instructions and the instructions configure the processing circuitry to perform the functions described for the processing circuitry. The dispenser controller 346 includes a wireless communication port 352 to communicate information wirelessly with the fleet management unit 234 using a wireless communication network (e.g., using a WiFi network). The dispenser controller 346 includes another communication port 354 to communicate information with the charger controllers 350 of the charger devices 226. The dispenser controller 346 and the charger controllers 350 may communicate using another communication network such as an Ethernet network. The charging system 200 can include a remote commands management system 237 to communicate commands wirelessly with the dispenser controller 346. The communication link with the remote commands management system 237 allows for remote control of the charge dispenser 230. A user may send commands remotely to the charge dispenser 230 through the remote commands management system 237. A user may access the remote commands management system 237 through the Internet by accessing a website. The devices for a job site may be displayed on the website. The user may select a charge dispenser 230, and send commands to start, stop, etc. The dispenser controller 346 accounts for conditions necessary to execute the command (e.g., cable is connected, charging request received, etc.). Given proper validations of the conditions for charging, the dispenser controller 346 can then execute received commands. This allows the user to control the charging system 200 remotely without having to physically go to the location of the system, which may be a large mining site or underground mining site. FIG. 4 is a diagram of an example of communication networks for the charger devices 226 and charge dispenser 230 of a charging system 200. The dispenser controller 346 communicates with the charger controllers 350 using a 4- wire Ethernet network. The charger devices 226 and the charge dispenser 230 may include interior sub-networks, such as a 2-wire Ethernet network (e.g., multi-drop network) and one or more controller area networks (CANs). The interior sub- networks are for communication among devices within the charger devices 226 and within the charge dispenser 230. Power allocation and distribution may be managed through messaging using the communication networks. Each charger device 226 can comprise a power input connector, a power output connector, a network connector and a charger controller. The power input connector, e.g., a receptacle, socket, plug, coupling device or the like, can be configured to receive power from a grid, such as a distributed grid network, a micro-grid or a local grid. Power from the grid can be provided through one or more of switch devices 228. The power output connector, e.g., a receptacle, socket, plug, coupling device or the like, can be configured to deliver power to a battery of machine 100. Power from the power output connecter can be provided through charge dispenser 230. The network connector can be configured to communicate with charge dispenser 230. In examples, the network connector can be an ethernet connector. In particular, the network connector can comprise a 4-wire ethernet communication device as shown in FIG. 4. The charger controller, e.g., charger controller 350, can comprise a computing device configured to adjust setting of charger device 226 and exchange information, e.g., data signals, with dispenser controller 346. Charger device 226 can include other components for electrical power management, such as switches, to control the input and output of electrical power thereto and therefrom. Charger device 226 can additionally include electrical converters, regulators, inverters, rectifiers, transformers and the like. Charger device 226 can additionally include cooling components to regulate the temperature of charger device 226. Charger device 226 can include various sensors for sensing operation of one or more of charger device 226 and / or electrical power being provided to the power input connector or being output at the power output connector. Examples of sensors that can be included in charger device 226 can comprise temperature sensors, current sensors, amperage sensors, frequency sensors, power sensors and the like. In particular, charger device 226 can include various sensors and electrical components configured to sense grid voltage and grid frequency. Charger device 226 can include memory (e.g., a computer-readable, non-transitory storage medium) to store information related to operational settings for different operating modes, such as standalone mode or parallel mode. The memory can further include grid parameters to facilitate monitoring for stressed grid conditions. For example, the memory can include threshold voltage levels and frequency levels at or above which a grid can be considered to be operating normally, e.g., unstressed. Voltage and frequency levels below the thresholds can indicated that the grid is drooping, e.g., the voltage and or frequency are dropping due to high or excess demand, e.g., power consumption, on the grid. Returning to FIG. 3, the dispenser controller 346 controls the charging of machine 100. The dispenser controller 346 receives an indication (e.g., a charge message or charge command) from the fleet controller 236 of the fleet management unit 234 to start a charging session with the machine 100. In response, the dispenser controller 346 determines if machine 100 is connected for charging. The dispenser controller 346 receives charging information from the machine 100. The charging information may be different for different types of BEMs. Machine 100 may include a charge interface controller (CIC) that sends the charging information to the dispenser controller 346. The charging information may include one or more of power, current, or voltage required for the charging of the machine. The charging information may include a state of charge (SOC) of the battery system 120 of the machine 100. The dispenser controller 346 uses the charging information to send one or more activation messages to the charger controllers 350 to activate or bring onboard multiple charger devices 226. The dispenser controller 346 may activate or bring onboard all the charger devices 226 for the charging session or activate a multiple number of chargers less than all the charger devices 226, such as for a parallel charging operation. The dispenser controller 346 may also activate only a single charger device 226 for standalone charging operations. In examples, a standalone charger device can be connected directly to machine 100 and communicate directly with the Charge Interface Controller (CIC) of machine 100, such as without the use of the charge dispenser 230. The charge dispenser 230 receives the charging energy from the activated or onboard charger devices 226 and delivers the charging energy to the machine 100 via the charging cable 232 during the charging session. At any time during the charging session, the dispenser controller 346 may change operation of the charger devices 226. For instance, the dispenser controller 346 may reduce the number of activated charger devices 226, increase the number of activated charger devices 226, or replace a charger device 226 during a charging session, such as by taking the corrective actions described herein to electrically switch to a different charger device or generate a warning or instruction for a user to physically replace a charger device after receiving a communication from a charger device. Also, the dispenser controller 346 may adjust the charging energy output of one or more of the activated charger devices 226 during the charging session or may receive an instruction from a charger device 226 indicating that charging energy output has been adjusted to match grid conditions as described herein. There may be several reasons for the dispenser controller 346 to change or adjust the activation of the charger devices 226 during a charging session. The change or adjustment of the charger devices may be in response to a scheduled change in the charging profile during a charging session. For example, the charging profile may include delivering more charge energy at the beginning of the charging session and reducing the charge energy later in the charging session. The dispenser controller 346 changes the charging configuration of the charger devices 226 in response to the change in demand of charging energy. Additionally, the change or adjustment of the charger devices may be in response to changes in grid performance, such as during a grid droop event when the grid is stressed from high demand and cannot effectively provide all of the power being requested. In examples, each charger device 226 can auto-correct output for changes in grid demand, either an increase or decrease charger output, without intervention from dispenser controller 346. As such, a charger device 226 may provide dispenser controller 346 an electronic communication indicating that a provided power output from such charger device has been adjusted due to changes in grid demand, such as from the existence or ending of a grid droop event. In another example, the dispenser controller 346 may detect a fault in one or more charger devices 226, and may deactivate the defective charger devices 226 and activate replacement charger devices 226. The dispenser controller 346 may detect a change (e.g., a decrease) in charge capability of one or more charger devices 226 and send one or more activation messages to change (e.g., increase) the number of active charger devices 226 in response. Additionally, each charger device 226 can perform a self-charger fault detection procedure to determine a fault in the operation of that charger. Such self-charger fault detection procedures can be automatically performed by each charger device 226 without intervention from dispenser controller 346. As such, a specific, previously identified (by dispenser controller 346) charger device 226 to be used in a charging operation may provide an electronic communication to dispenser controller 346 indicating that a self-performed charger fault detection operation has failed and that such charger device 226 intended to be used for a charging operation should be replaced. The dispenser controller 346 may adjust the charging energy output of one or more of the activated charger devices 226 during the charging session to balance the load among the onboard charger devices 226. Balancing the load during a charging session may be useful to extend the operating life of the charger devices 226. The dispenser controller 346 may adjust the charging energy output of one or more of the activated charger devices 226 during the charging session in response to temperature information. The dispenser controller 346 may receive temperature information regarding the charging cable 232 (e.g., from one or more temperature sensors monitoring temperature of the charging cable 232). If the temperature increases above a predetermined threshold the dispenser controller may adjust the charging energy output of the charger devices 226 to reduce charging energy in the charging cable 232 or deactivate a charger device 226 to reduce charging energy in the cable. The dispenser controller 346 may also change operation of a cable cooling system to address the increase in cable temperature. The dispenser controller 346 may adjust the charging energy output of one or more of the activated charger devices 226 during the charging session based on the power derating of the system. For instance, the dispenser controller 346 may adjust the output of the onboard charger devices 226 when power output of the charge dispenser 230 nears a maximum power rating of the charge dispenser 230. The dispenser controller 346 may adjust the output of the onboard charger devices 226 when the output of the charge dispenser 230 nears a maximum power rating of the machine 100. The dispenser controller 346 may receive an alert of reaching the power limit of the machine 100 from the CIC of the machine 100. The dispenser controller 346 uses the power derating information of the charge dispenser 230 or the machine 100 to automatically adjust power output in real- time. The power derating values for the machine 100 may increase or decrease at any time. The power derating of the charge dispenser 230 may be a set value unless changed by a user on site or through the fleet management unit 234. The dispenser controller 346 may also adjust the charging energy output of one or more of the activated charger devices 226 during the charging session in response to external commands (e.g., commands from the fleet management unit 234) based on conditions of the job site. The external commands may be received wirelessly over-the-air to instruct the charge dispenser 230 to limit power output. As explained previously herein regarding FIG. 2, the charging system 200 can include a robotic connector system 238 to connect and disconnect the charging cable 232 to a charging receptacle of the machine 100. The robotic connector system 238 includes a robot controller 356. To start the charging session in response to the indication from the fleet controller 236 to do so, the dispenser controller 346 sends a connect message to the robot controller 356 and the robotic connector system 238 changes from a storage position to connect the charging cable to the machine 100. The dispenser controller 346 may automatically detect connection of the charging cable 232. For instance, connection of the charging cable 232 to the machine 00 may cause a connection signal (e.g., sent from the machine 100) to be detected by the dispenser controller 346. The dispenser controller 346 may proceed to the next step of the charging session (e.g., receiving charge information from the CIC of the machine 100 in response to detecting that the charging cable 232 is connected. Before starting the charging session, the dispenser controller 346 may perform a cable check sequence prior to entering the charging session to determine if there are any faults in the charging cable connection between the charge dispenser 230 and the machine 100. When charging of the machine 100 is complete, the dispenser controller may detect the charge complete condition as the SOC of the machine 100, or receive an indication of charging complete from the CIC of the machine 100. The dispenser controller 346 sends an indication to fleet controller 236 that charging is complete. The fleet controller 236 may then schedule a new charging session that the dispenser controller 346 can perform using a different configuration of charger devices 226 depending on the charging requirements of the new machine 100. If the charging system 200 uses a robotic connector system 238 to connect the charging cable 232, the dispenser controller 346 may send a disconnect message to the robot controller 356 to disconnect the charging cable from the charging receptacle of the machine 100 when the dispenser controller 346 determines that charging is complete. The dispenser controller 346 may detect that the charging cable 232 is disconnected when the connection signal is no longer detected. The dispenser controller 346 may detect that the charging cable 232 is disconnected by receiving an indication from the robot controller 356 that the charging cable 232 is disconnected and the robotic connector system 238 has returned to the storage position. The dispenser controller 346 informs the fleet controller 236 that the charging is complete and the machine 100 can be moved away from the charge dispenser 230. Aggregating the output of multiple charger devices 226 provides higher capacity charging than approaches that use one charger device 226. The aggregating techniques described are modular and the number of chargers that can be brought onboard is flexible to allow charging of different types of machines 100. Industrial FIG. 5 is a state diagram of an overview of the different states in which the charge dispenser 230 can operate. A charging session may start from the Standby state 505, in which the charge dispenser is waiting for a machine to be ready to charge. The charge dispenser 230 may enter the Standby state upon power up after an Initialize state 510. In the Standby state, the charge dispenser monitors for an indication that a BEM is connected. When a connection is detected, the charge dispenser changes to the Connected state 515. If the robotic connector system is present, it will move from the Standby state to the Robot Connecting state 520 to monitor for the robotic connection of the charging cable to the machine. From the Connected state, the charge dispenser changes to a Cable Check state 525. In the Cable Check state, the charge dispenser 230 will perform a cable check to ensure there are no faults in one or both of the charging cable connection to the BEM and the cable connections to the charger devices. If there is a fault detected during cable check, the charge dispenser changes to a Fault state 530 in which Fault subroutines may be performed by the dispenser controller 346 to determine the fault and either mitigate the fault or terminate the charging session and send an alert to the fleet management unit related to the fault. If there is no fault detected, the system will change to the Pre- Charge state 535 to receive charge information and configure the charger devices 226 using the charge information. From the Pre-Charge state, the charge dispenser changes to the Charging state 540 during which the charging of the BEM is performed. When charging is complete, the charge dispenser goes through a disconnecting procedure that may include Robot Disconnecting state 545 before returning to the Standby state. During any of the Initialize, Standby, Connect, Pre- Charge, or Charge states, the charge dispenser checks for faults and may enter the Fault state upon detection of a fault in one or more of a charger device, charger cable connecting charger device, charging cable to the BEM, the charge dispenser itself. FIG.6 is a flow diagram of an example of a method 600 of operating a charge dispenser for charging a non-road BEM. The method 600 may be performed using the charge dispenser 230 described previously herein that has multiple charger devices 226 connected to it. At block 605, the charge dispenser 230 is in a Standby state waiting for information regarding charging of a machine 100. The fleet management unit 234 may move the machine 100 to the location of the charge dispenser 230 and may send a command to the charge dispenser 230 to charge the machine 100. At block 615, the dispenser controller 346 of the charge dispenser 230 waits for a connecting indication from the machine 100, or charging cable 232, that the machine 100 is connected for charging and the charge dispenser 230 enters a Connected state. If a robotic connector system 238 is present, the charge dispenser 230 may send a request to the robotic connector system 238 to connect a charging cable 232 to the machine 100. At block 635, the dispenser controller 346 configures the charger devices 226. This configuration may be performed during a Pre-Charge state and includes setting two or more charger devices 226 to an onboard state to provide charge energy in parallel to the charge dispenser 230. The dispenser controller 346 may configure the charger devices 226 according to charging information for the machine 100 received from the fleet management unit 234 or the machine 100. At block 640, the charge dispenser 230 enters a Charging state when the conditions for charging are met. The dispenser controller 346 may send updates of charging status to the fleet management unit 234 when in the Charging state. At block 650, the dispenser controller 346 changes the number of charger devices 226 activated in parallel and providing charge during the charging state. The dispenser controller 346 may change number of charger devices 226 activated in response to temperature information regarding the charging cable 232, in response to a fault detected in the charging system 200, or in response to a change in one or both of a change in charge demand and a change in charger capability of one or more of the charger devices 226. Additionally, the dispenser controller 346 may adjust the charging energy output of one or more of the activated charger devices 226 during the charging session in response to a change in charge demand or a change in charger capability of individual charger devices 226. At block 655, the charge dispenser 230 continues the charging session until charging is complete. The charge complete may be sent from the CIC of the machine 100, or detected by the dispenser controller 346. When the machine 100 is charged, the dispenser controller 346 waits for an indication that the BEM is disconnected at block 660. If the robotic connector system 238 is present, the dispenser controller 346 may send a request to the robotic connector system 238 to disconnect the charging cable 232, and the robot controller 356 of the robotic connector system 238 may return a response when the cable is disconnected and stowed. When the dispenser controller 346 receives the response, the dispenser controller 346 may send message to a fleet controller 236 of a fleet management unit 234 that the machine 100 can be moved away from the charge dispenser. FIG. 7 is a line diagram of method 700 for auto-configuring one or more of charger device 226 in different charging modes and under different grid conditions to charge machine 100. At block 702, charger device 226 can be in a Standby state waiting for information regarding charging of machine 100 from charge dispenser 230. The fleet management unit 234 may move the machine 100 to the location of the charge dispenser 230 and may send a command to the charge dispenser 230 to charge the machine 100. At block 704, charger device 226 can receive an instruction from charge dispenser 230 for an operation mode to operate in. Charger dispenser 230 can convey corresponding instructions to one or more of charger device 226 to operate alone in a standalone mode or in a group in a parallel (skid) mode. In additional examples, charger device 226 can receive an operating mode instruction directly from CIC of machine 100. In examples, charger device 226 can auto- configure itself in a standalone operating mode, such as when plugged into machine 100, and auto-configure itself in a parallel operating mode when receiving a signal from charger dispenser 230. At block 706, charge dispenser 230 or a CIC of machine 100 can electronically communicate an instruction signal to charger device 226 to operate in a standalone mode. Standalone mode can comprise a slow charging mode for machine 100. Standalone mode can be used when there is only a single charger device 226 installed, when multiple other charger devices 226 that are installed are already being used, when grid demand is high, when the machine 100 to be charged has low priority, or when the machine 100 to be charged will not be used for a long period of time. At block 708, charge dispenser 230 can electronically communicate an instruction signal to charger device 226 to operate in a parallel mode. Parallel mode may also be referred to as skid mode because, for example, multiple charger devices 226 on a single skid or pallet can be connected in parallel and used at the same time. Parallel mode can comprise a fast-charging mode for a machine 100. is provided to a machine 100. Parallel mode can be used when there are multiple charger devices 226 installed, when multiple charger devices 226 that are installed are not currently being used, when grid demand is low, when the machine 100 to be charged has high priority, or when the machine 100 to be charged will be used in a short period of time. At block 710, charger device 226 can perform an auto-configuration process to adjust charging settings for the operating mode provided by charge dispenser 230. Examples of charging settings that can be adjusted for different operating modes can include voltage, frequency, current (amperage) and the like. In examples, charger devices 226 can output DC charging power to a battery system. The input to the charger can be AC or DC depending on the charger. Thus, in examples, charger devices 226 can perform AC / DC converting or DC / DC converting. In examples, both AC / DC type chargers and DC / DC type chargers can be located on one skid. Charge settings can also be adjusted based on particulars of machine 100 that is being charged or batteries of machine 100 that is being charged, such as temperature, coolant flow, current, degradation state, charge state, health state, capacity, energy, power, and ambient temperature. For operation in standalone mode, charge dispenser 230 can receive charging commands from the CIC of the machine 100. The CIC can communicate charging requirements like voltage, current, power settings or limits. Charged dispenser 230 can also receive the charge command and stop command from the CIC. Additionally, faults detected as disclosed herein can be reported to the CIC. For operation in parallel mode, charge dispenser 230 can receive charging commands from the dispenser controller 346. The dispenser controller gets the charging requirements from the CIC and configures the charger devices. Additionally, faults detected as disclosed herein can be reported to the charge dispenser 230. At block 712, charger device 226 can perform a fault detection procedure. A fault detection procedure can be automatically performed by a charger device 226 for that charger device. The fault detection procedure can determine the presence or absence of various connections with charger device 226, improper temperatures of the charger device, improper electrical loads on the charger device and the like. Further description of the fault detection procedure is provided with reference to FIG. 8. At block 714, charger device 226 determine if the fault detection procedure passed or failed. At block 716, charger device 226 can determine that the fault detection procedure passed and can proceed to detect grid conditions to block 716. At block 718, charger device 226 can determine that the fault detection procedure failed and can proceed to performing one or more corrective actions at block 728. Corrective actions can comprise actions by charger device 226, such as issuing a communication signal to charge dispenser 230 or the CIC of machine 100. Additionally, corrective actions can comprise actions by charge dispenser 230 or the CIC of machine 100 to perform tasks, such as to find a replacement charger device for a faulted charged device. At block 720, charger device 226 can determine that the grid is not stressed. As such, charger device 226 can determine that the frequency and voltage of the grid is what should be expected for the type of grid connected thereto. As such, charger device 226 can determine that the grid has enough available power to supply to charge dispenser 230 as has been requested. Thus, method 700 can proceed to block 724. At block 722, charger device 226 can determine that the grid is stressed. As such, charger device 226 can determine that the frequency and voltage of the grid is not what should be expected for the type of grid connected thereto. As such, charger device 226 can determine that the grid does have enough available power to supply to charge dispenser 230 as has been requested without potentially incurring a performance issue or triggering a circuit breaker. Thus, method 700 can proceed to block 726. At block 724, charger device 226 can proceed to allow power to be communicated to charge dispenser 230. Coming from operation 720 charger device 226 can provide the amount of power requested by charge dispenser 230. Coming from operation 726 charger device 226 can provide less than the amount of power requested by charge dispenser 230. At block 726, charger device 226 can derate the power output to charge dispenser 230. The derated power can be less than charge dispenser 230 has requested. Thus, charger device 226 can provide a communication to charge dispenser 230 to expect less power than what is expected. Further description of block 722 and block 726 is provided with reference to FIG. 9. At block 728, charger device 226 can determine if charger device is operating in standalone mode or parallel mode to take an appropriate corrective action. At operation 730, charge dispenser 230 can take corrective action for parallel mode operation. For parallel mode operation, the corrective action can be electrically switching over to a different charge device 226 that is not in a fault state. Thus, the charger device 226 that self-detects a fault state can provide an instruction to charge dispenser 230 to find another charger device to use that is already physically wired in for parallel operation, but not electrically connected by operation of switches, etc. Corrective action provided by the charge device 226 can be to provide a communication signal to charge dispenser 230 to perform a corrective action. At operation 732, the CIC for machine 100 can take corrective action for standalone mode operation. For standalone mode operation, the corrective action can be electrically switching over to a different charge device 226 that is not in a fault state. Thus, the charger device 226 that self-detects a fault state can provide an instruction to the CIC of machine 100 to find another charger device to use that is already physically wired in for standalone operation, but not electrically connected by operation of switches, etc. In examples, charger device 226 can take corrective action for standalone mode operation when appropriate. That is any communication that charge device 226 can provide to charge dispenser 230 can additionally or alternatively be provided to the CIC of machine 100 and vice versa. Furthermore, for standalone mode operation, the corrective action can be to request physical replacement of the charger device. Thus, charger device 226 can generate a signal to be provided to charge disposer 230 to forward to fleet management unit 234 indicating that a request for a replacement charger device has been made. Thereafter, fleet management unit 234 can dispatch appropriate maintenance personnel or technicians to retrieve a non-faulted charger device to replace the faulty charger device. Note, it is also possible for the corrective action for the parallel operating mode to comprise physical replacement of the charger device. After appropriate corrective actions have been taken, method 700 can proceed to providing power to charge dispenser 230 as requested or as adjusted via method 700. FIG. 8 is an example of state diagram 800 of operation of charger device 226 in accordance with a charger default detection procedure of the present disclosure. FIG. 8 provides an overview of the different states in which the charge dispenser 230 can operate. A charging session may start from the Standby state 805, in which the charger device 226 is waiting for a machine to be ready to charge. The charger device 226 may enter the Standby state upon power up after an Initialize state 810. In the Standby state, the charger device 226 can monitor for instruction from a CIC that it is connected to a BEM, or instruction from a dispenser that it is connected to a dispenser. The CIC or charge dispenser 230 can provide an instruction that a BEM is connected, and a charging operation is to be performed. When instructions from the CID or dispenser 230 are received, the charger device can change to the Connected state 815. From the Connected state 815, the charger device 226 can change to a Cable Check state 825. In the Cable Check state 825, the charger device 226 can perform a cable check to ensure there are no faults in one or both of the charging cable connections to switch devices 228 and charge dispenser 230. If there is a fault detected during cable check, the charger device can change to a Fault state 830 in which Fault subroutines may be performed by the charger controller 350 to determine the fault and either mitigate the fault or terminate the charging session and send an alert to the fleet management unit related to the fault so that corrective maintenance can be performed by appropriate personnel. Other fault conditions that can be checked for include improper temperature of charger device 226, improper electrical properties of charger device 226 and the like. If there is no fault detected, the system will change to the Pre- Charge state 835 to receive operational information from charge dispenser 230 to perform automatic self-configuration of the charger devices 226 using the operational information. From the Pre-Charge state, the charger device can change to the Charging state 840 during which the charging of the BEM is performed. When charging is complete, the charger device 226 can return to the Standby state. During any of the Initialize, Standby, Connect, Pre-Charge, or Charge states, the charger device 226 can check for faults and may enter the Fault state upon detection of a fault in one or more of the charger device itself, a charger cable connecting the charger device to another component, or the lie. FIG.9 is a line diagram of method 900 of derating output of charger device 226 of the present disclosure to, for example, alleviate grid stress. At operation 902, the charger device 226 can be in a Standby state waiting for information regarding charging of a machine 100, such as in the form of instructions from charge dispenser 230. Thus, at operation 902, charger device 226 can receive an instruction to provide a requested amount of power. At operation 904, charger device 226 can sense parameters of the grid system connected to charger device 226 through switch devices 228. Charger device 226 can sense various parameters of the grid system, such as voltage and frequency. At operation 906, charger device 226 can compare one or more sensed parameters of the grid to threshold parameters. The threshold parameters can be stored in memory of charger device 226. The threshold parameters can be provided by charge dispenser 230, such as after being obtained from fleet management unit 234. The threshold parameters can represent operating levels of grid at or above which the grid is operating adequately to provide all requested power. At operation 908, charger device 226 can determine if the sensed parameter is less than, equal to or greater than the threshold parameter. At operation 910, charger device 226 can determine that the sensed parameter is not less than (e.g., is greater than or equal to) the threshold parameter. Thus, method 900 can continue to operation 916. At operation 912, charger device 226 can determine that the sensed parameter is less than (e.g., is not greater than or equal to) the threshold parameter. Thus, method 900 can continue to operation 914. At operation 914, charger device 226 can derate the output of charger device 226. Derating of the output of charger device 226 can comprise outputting less power than what has been requested by charge dispenser 230. The amount of derating can be based on different factors. In examples, the amount of derating can correspond to the amount of grid droop. For example, the power output can be derated by a proportion equal to the amount that the sensed frequency or voltage is below the threshold frequency or voltage. To support a stressed power grid, input and output voltage or frequency deviation, charger device 226 can derate the power output to allow the grid to recover. When configured as a standalone or skid / parallel charger the individual chargers measure their individual input AC voltage or frequency and can react independently. If the AC voltage or frequency is lower than the expected values, the charger will derate the output current proportionally to reduce the acting load on the electrical utility grid or microgrid which allows for recovery. This is done pre-emptively, such as without input from dispenser controller 346, as to avoid grid outage or shutdown and to avoid independent charger circuit breaker activation, skid circuit breaker activation, or work sight circuit breaker activation. At operation 914, charger controller 350 can additionally configure charger devices 226. This configuration may be performed during a Pre-Charge state and can include any of the configurations described herein, such as setting two or more charger devices 226 to a parallel charge state to provide charge energy in parallel to charge dispenser 230. The dispenser controller 346 or the charger controller 350 may configure charger devices 226 according to charging information for the machine 100 received from the fleet management unit 234 or the machine 100, as described herein. At operation 916, charger device 226 can output power to charge dispenser 230 so that charging operations can be performed. When coming from operation 914, the power to charge machine 100 can be derated. When coming from operation 910, the power can be not derated and can be the amount requested by charge dispenser 230. At operation 918, charger device 226 can continuously monitor grid parameters to determine if derating is desired or if the grid has recovered. As such, the amount of derating can be adjusted, or the derating can be removed if grid conditions recover, e.g., the droop has been eliminated. At operation 920, dispenser controller 346 can continuously monitor to determine if machine 100 is charged. For example, dispenser controller 346 can monitor for an input signal or instruction from machine 100 or fleet management unit 234 indicating or including an instruction that machine 100 is properly charged, e.g., fully charged, and that charging operations can stop. At operation 920, charge dispenser 230 can enter a Charging state when the conditions for charging are met. Dispenser controller 346 may send updates of charging status to the fleet management unit 234 when in the Charging state. At operation 920, dispenser controller 346 can changes the number of charger devices 226 activated in parallel and providing charge during the charging state. Dispenser controller 346 may change number of charger devices 226 activated in response to temperature information regarding the charging cable 232, in response to a fault detected in the charging system 200, or in response to a change in one or both of a change in charge demand and a change in charger capability of one or more of charger devices 226. Additionally, dispenser controller 346 may adjust the charging energy output of one or more of the activated charger devices 226 during the charging session in response to a change in charge demand or a change in charger capability of individual charger devices 226. At operation 920, charge dispenser 230 can continue the charging session until charging is complete. The charge complete may be sent from the CIC of the machine 100, or detected by the dispenser controller 346. When the machine 100 is charged, the dispenser controller 346 waits for an indication that the BEM is disconnected at operation 922. If the robotic connector system 238 is present, the dispenser controller 346 may send a request to the robotic connector system 238 to disconnect the charging cable 232, and the robot controller 356 of the robotic connector system 238 may return a response when the cable is disconnected and stowed. When the dispenser controller 346 receives the response, the dispenser controller 346 may send message to a fleet controller 236 of a fleet management unit 234 that the machine 100 can be moved away from the charge dispenser. Unless explicitly excluded, the use of the singular to describe a component, structure, or operation does not exclude the use of plural such components, structures, or operations or their equivalents. The use of the terms “a” and “an” and “the” and “at least one” or the term “one or more,” and similar referents in the context of describing the invention (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The use of the term “at least one” followed by a list of one or more items (for example, “at least one of A and B” or one or more of A and B”) is to be construed to mean one item selected from the listed items (A or B) or any combination of two or more of the listed items (A and B; A, A and B; A, B and B), unless otherwise indicated herein or clearly contradicted by context. Similarly, 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 of: A; B; C; A and B; A and C; B and C; A, B, and C; or multiple of any item such as A and A; B, B, and C; A, A, B, C, and C; etc. The above detailed description is intended to be illustrative, and not restrictive. The scope of the disclosure should, therefore, be determined with references to the appended claims, along with the full scope of equivalents to which such claims are entitled.

Claims

Claims 1. A modular charging system (200) for charging a battery electric machine (BEM) (100), the modular charging system comprising: a dispenser device (230) for connecting to the BEM and delivering a charge to the BEM; and a first modular charger device (226) to provide the charge for the dispenser device from a power grid, the first modular charger device comprising: a network connector for communicating with the dispenser device; a power input connector for connecting to the power grid; a power output connector for connecting to the dispenser device; and a charger controller (350) configured to: receive an instruction from the dispenser device or the BEM to operate in a mode comprising a standalone mode or a parallel mode; auto-configure the first modular charger device for operation in the mode received in the instruction; and check for a charger input problem, wherein checking for the charger input problem comprises: allowing the power output connector to output power form the power grid if a charger input problem is not detected; and provide a communication signal to the dispenser device or the BEM for performing a charger corrective action if a charger input problem is detected.

2. The modular charging system of claim 1, wherein: checking for a charger input problem comprises performing a charger fault detection procedure to determine if a charger fault condition exists in the first modular charger device (226); and the charger input problem comprises existence of the charger fault condition in the first modular charger device,wherein the charger fault detection procedure comprises: checking for connection of cables (348) between the first modular charger device and the dispenser device or the BEM; and checking for connection of cables between the first modular charger device and a switch device (228) connecting the first modular charger device to a grid system, wherein the charger corrective action comprises the dispenser device (230) or the BEM performing a charger replacement operation.

3. The modular charging system of claim 2, wherein: the charger controller (350) is configured to operate in the parallel mode after receiving an instruction to operate in the parallel mode from the dispenser device; and the charger replacement operation comprises the dispenser device connecting to a replacement modular charger device connected in parallel with the first modular charger device, wherein connecting to the replacement modular charger device connected in parallel with the first modular charger device comprises activating one or more switches to disconnect from the first modular charger device (226) and connect to the replacement modular charger device.

4. The modular charging system of claim 2, wherein: the charger controller (350) is configured to operate in the standalone mode after receiving an instruction to operate in the standalone mode from the BEM; and the charger replacement operation comprises the first modular charger device going into a standby mode to receive input from a replacement power charger device that physically replaces the first modular charger device or issuing an instruction for the BEM to connect to a replacement modular charger device, wherein going into the standby mode to receive input from a replacement power charger device comprises opening one or more switches to disconnectpower from the grid system from being delivered to the first modular charger device (226).

5. The modular charging system of claim 2, wherein: checking for the charger input problem comprises detecting a stressed grid condition; and the charger input problem comprises existence of a stressed grid, wherein the charger corrective action comprises the charger controller (350): providing a communication signal to the dispenser device indicating that a derated power supply will be provided to the dispenser device; and derating output at the power output connector to alleviate demand on the power grid, wherein detecting the stressed grid condition comprises sensing a grid droop, wherein sensing a grid droop comprises sensing AC voltage or frequency input that is lower than a threshold AC voltage or frequency input.

6. A method of auto-configuring a charger device (226) for providing power from a grid system to a non-road battery electric machine (BEM) (100), the method comprising: receiving an instruction, by the charger device, from a charge dispenser (230) or a BEM to prepare for a charging operation in a designated mode; auto-configuring, by the charger device, to operate in the designated mode; auto-detecting, by the charger device, a connected state in which the charger device is connected to the charge dispenser and the grid system by performing a charger fault detection procedure; issuing a signal to perform a corrective action for a fault state if the connected state is detected to be faulty; andentering, by the charger device, a charging state in which the charger device provides power to the charge dispenser if the connected state is detected to be not faulty.

7. The method of claim 6, wherein the charger fault detection procedure comprises: checking for connection of cables (348) between the charger device and the charge dispenser or the BEM; and checking for connection of cables between the charger device and a switch device (228) connecting the charger device to a grid system.

8. The method of claim 7, wherein the corrective action comprises the charger device generating a signal for the charge dispenser (230) or the BEM to perform a charger replacement operation, wherein: the designated mode comprises a parallel operation mode communicated by the charge dispenser; and the charger replacement operation comprises connecting to a replacement modular charger device connected in parallel with the charger device, wherein connecting to the replacement modular charger device connected in parallel with the charger device comprises activating one or more switches to disconnect from the charger device (226) and connect to the replacement modular charger device.

9. The method of claim 8, wherein: the designated mode comprises a standalone operation mode communicated by the BEM; and the charger replacement operation comprises going into a standby mode to receive input from a replacement power charger device that physically replaces the charger device or issuing an instruction for the BEM to connect to a replacement modular charger device, wherein going into the standby mode to receive input from a replacement power charger device comprises opening one ormore switches to disconnect power from the grid system from being delivered to the charger device (226).

10. The method of claim 6, further comprising: detecting, by the charger device, a stressed grid condition indicated by a grid droop; providing a communication signal to the charge dispenser indicating that a derated power supply will be provided to the charge dispenser if a stressed grid condition is detected; and derating output to the charge dispenser to alleviate demand on the grid system; wherein detecting the stressed grid condition comprises sensing a grid droop; and wherein sensing a grid droop comprises sensing AC voltage or frequency input that is lower than a threshold AC voltage or frequency input.

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