Electric crane operating modes

Abstract

This invention provides a method for charging the battery of a mobile crane while the crane is in motion. [Solution] The mobile crane system configuration includes an internal combustion engine (ICE). The energy from the ICE is used for the mobile crane's travel and for charging the mobile crane's battery with a generator. The desired state of charge (SoC) of the battery when the mobile crane arrives at its destination is defined. The charging power rating required by the ICE for charging the battery is calculated and supplied to the generator. The battery is charged from its current charge state so that the desired state of charge is available at the calculated arrival time of the mobile crane.

Description

TECHNICAL FIELD

[0001] The present invention relates to a crane, for example a mobile crane, that is provided with at least one electric drive device, and to possible operation modes of said electric drive device.

BRIEF DESCRIPTION OF THE DRAWINGS

[0002] [Figure 1] A diagram showing an example of the system configuration of a mobile crane.

DETAILED DESCRIPTION OF EMBODIMENTS

[0003] Electric power for operating the at least one electric drive device can be obtained, for example, from one or more batteries. The batteries are mounted in or on the crane and can be charged by various methods.

[0004] Electric cranes or hybrid cranes may be provided with, for example, a high-voltage (HV) battery. The high-voltage battery may be, for example, a high-performance rechargeable battery having a voltage of 60V or more, or from 200V up to a maximum of 800V. The high-voltage battery functions as the main energy source for electric driving, and can store energy for, for example, driving the mobile crane to perform normal operations. The battery may be, for example, a lithium-ion battery.

[0005] The high-voltage battery may be cooled or heated by a thermal management system in order to protect the high-voltage battery from overheating and maintain it within the optimal operating temperature range.

[0006] Figure 1 is a diagram showing an example of the system configuration of a mobile crane. In Figure 1, the high-voltage battery is denoted as "Battery".

[0007] For example, one or more low-voltage (LV) batteries (60V or less, e.g., 12V, 24V, or 48V, not shown in Figure 1) installed in a mobile crane may be charged by the aforementioned high-voltage batteries, which are charged externally or internally. Rechargeable low-voltage batteries may be used in a mobile crane, for example, as an on-board mains supply, or to power other electrical devices such as lighting, control devices, electric servo systems, or to start an internal combustion engine. In this specification, (usually) references to batteries refer to the aforementioned high-voltage batteries unless otherwise specified.

[0008] 1. Operating mode for charging high-voltage batteries High-voltage batteries can be charged externally, i.e., by an external power connector or external power supply. Alternatively or additionally, high-voltage batteries can also be charged internally, for example, using a generator mounted on a mobile crane. For example, the charging methods described below are available.

[0009] 1.1. Charging from an external power source For example, an external power connector for charging the high-voltage battery of a mobile crane is either an AC or DC connector, powered, for example, by a mains power source or an external generator. AC charging is generally performed at a lower power rating and is slower overall than DC charging. DC charging uses a higher power rating and higher currents, such as 200A or 300A or more, allowing for relatively faster charging.

[0010] AC charging may be, for example, three-phase charging at 400V, 32A, or 64A (common plugs: IEC 62196-2 and IEC 62196-3 (AC Type 2) or optionally SAE 3068 (AC Type 2)).

[0011] The crane's battery can be charged in situ, for example, from an external AC power source (AC-net) via (optional) the mobile crane's (optional) internal onboard charger. The operator can, for example, set a maximum charging current appropriate for the available mains power source and battery. Typical maximum charging current values ​​range from 1A to 64A. To protect the battery and extend its service life, the operator can also specify a limit or threshold for the maximum charge state (maximum %AC). These data or presets may be utilized by the charger's control system during battery charging.

[0012] DC charging can be performed, for example, at a maximum of 800V and a maximum of 200A or 300A (common plugs: IEC 62196-2 and IEC 62196-3 (DC Type 2) or optionally SAE 3068 (DC Type 2)).

[0013] The crane's battery can be charged on-site, for example, from an external DC power source ("DC charger") via the mobile crane's internal charging interface ("DC interface"). The charging interface can communicate with an external charging device, for example. The external charging device can perform safety monitoring, such as insulation measurement.

[0014] To maintain or protect high-voltage batteries and improve their overall service life, the charge state of high-voltage batteries may be set, for example, by a battery management system. This ensures that high-voltage batteries are never completely discharged (0%) or completely charged (100%). In other words, the battery charge state is set to always be between a minimum charge state and a maximum charge state, for example, between 5% and 95% of the high-voltage battery's maximum charge. This 5% to 95% range of the high-voltage battery's effective charge state may be displayed, for example, as 0% to 100% on the charge state screen.

[0015] Similar to AC charging, operators can define the desired maximum charge state (SoC) of the battery to protect it and extend its lifespan.

[0016] When the charging cable is connected to the crane, the crane control system prohibits starting the internal combustion engine to prevent unintentional damage to the engine.

[0017] A smart control unit (SCU) is an additional controller for high-voltage systems. The smart control unit forms an intelligent control unit for controlling, monitoring, and optimizing the battery operation, safety functions, and power electronics of the drive system, generator, and thermal management system. Even when the crane's low-voltage supply is unavailable, the smart control unit can ensure the low voltage (e.g., 24V) required by the system via the high-voltage battery and DC / DC converter, even when the high-voltage battery is being charged (AC or DC) or when the battery is being adjusted.

[0018] For example, when the ignition switch of the mobile crane is off and AC or DC charging is enabled, and / or battery adjustment is scheduled, the superstructure display ODM and carrier display CDM can automatically display battery information. In this operating state, it is preferable that all other crane functions are disabled. Even when the mobile crane is off, it is preferable that the superstructure display ODM and carrier display CDM remain automatically on during AC or DC charging, and during battery maintenance or adjustment, to display the relevant charging and battery status values.

[0019] The superstructure display ODM and / or carrier display CDM may display one or more or all of the following information on the screen during the charging process: Charging power rating (kW), Charging status (SoC), Target charge state (the maximum charge level to be reached during charging), The predicted or calculated time to reach the target charge state. Target time (of the day) when battery adjustment or battery maintenance (if enabled) will be completed, A warning symbol indicating that the internal combustion engine (ICE) cannot be started until the charging plug has been removed.

[0020] The State of Charge (SoC) quantifies the remaining usable capacity of a battery at a given point in time, and is shown in relation to, for example, the individual State of Health (SoH). The State of Charge (SoC) can be expressed as a percentage (0% is empty, 100% is full). Another form of this indication may be used, called the depth of discharge. The depth of discharge indicates the percentage of the battery's nominal capacity that can be drawn out without reducing its lifespan.

[0021] It is preferable that the engine ICE cannot be started when the high-voltage battery is being charged by an external charging power source, when an AC or DC charging cable is connected to the mobile crane, or when a charging plug is inserted into the mobile crane. When an AC or DC charging cable is connected to the mobile crane, or when a charging plug is inserted into the mobile crane, the engine ICE can be automatically stopped, for example, by a control system. For this purpose, additional speed checks can also be performed. That is, the engine will only be stopped, for example, when the speed of the mobile crane is below a specified speed. The specified speed may be, for example, 8 km / h. This prevents the engine from unintentionally stopping, for example, when the mobile crane is moving at a speed exceeding the specified speed.

[0022] Operators of the mobile crane can manually interrupt the charging process at any time, for example, by operating a corresponding switch.

[0023] The battery of a mobile crane should be operated within specific temperature limits to obtain the maximum or full charging and discharging capacity of the battery. The temperature range T in which the battery operates should be, for example, between 5°C and 30°C, that is, 5°C < T < 30°C.

[0024] Advantageously, the battery adjustment mode is provided, for example, to define a start time at which the crane is or should be ready for operation. At the start time, one or more batteries are at an optimal or preferred temperature, for example within the aforementioned temperature range T. When the battery adjustment mode is activated, for example, a desired "mobile crane start time" may be displayed. The thermal management system TMS of the mobile crane starts the adjustment (e.g., cooling or heating) of the battery at a pre-calculated time, so as to obtain the desired optimal or ideal state of the battery at the "mobile crane start time". The thermal management system TMS can take into account the ambient temperature and the current general state or operating state of the battery. The battery adjustment mode is also provided to achieve the optimal battery temperature for battery charging at a specified time.

[0025] The superstructure display ODM and / or the carrier display CDM can, for example, also be designed as a touch screen, and may represent other input means known per se. Through these input means, the operator can input the following battery adjustment parameters. The scheduled time for the crane to start operation or start charging, Activation (on / off) of battery adjustment.

[0026] 1.2. Charging using a generator (ICE) The high-voltage battery of the mobile crane can be charged on site or during travel using the generator of the mobile crane. This generator is directly or indirectly driven by the (diesel) engine of the mobile crane.

[0027] When the battery is charged in place (i.e., when the mobile crane is stopped and supported by its tires or outriggers), the crane is not normally in operation, and the goal is generally to charge the battery as quickly as possible. When the battery is charged while in motion, the goal is generally to arrive at the mobile crane's operational site with the "best possible" battery charge state, i.e., a fully charged battery or a charge state corresponding to a desired charge state (SoC) defined by the operator.

[0028] The operator can interrupt this charging process and switch to a different operating mode at any time.

[0029] 1.2.1. On-site charging In the high-voltage battery charging process using a generator, the generator is connected to the engine via a power take-off (PTO). The drive gearbox is configured, for example, so that the vehicle's drive unit is in neutral when the power take-off PTO is activated.

[0030] The drive gearbox can be set to an optimal gear ratio, such as 16 speeds, to operate the generator at an efficient speed.

[0031] The engine (ICE) is preferably operated at a speed that allows for efficient charging, such as 1450 revolutions per minute (rpm).

[0032] The generator operates in torque mode. In torque mode, the system's control unit determines or sets the torque to match the allowable charging current of the high-voltage battery. Preferably, the torque is determined based on, or in accordance with, the charge state (SoC) of the high-voltage battery and the battery temperature or system temperature.

[0033] The control system can also be designed to extend charging time and achieve more economical charging. For example, a diesel engine (ICE) operates at low revolutions, such as 1000 revolutions per minute.

[0034] 1.2.2. Charging while driving The battery can be charged while the crane is moving, i.e., while it is traveling. In this case, the generator is driven by an internal combustion engine (ICE) to charge the battery.

[0035] The operator can select from the following modes: Maximum Charging Time Optimized Charging, Eco Charging, and Drive Pro (lower level), and can switch between these while driving.

[0036] The drive gearbox is configured to enable the power take-off (PTO) and simultaneously allow the mobile crane to travel or move. This can be achieved with a normal drive and / or gear ratio, or an off-road gear and / or gear ratio. The drive gearbox can operate as usual.

[0037] The power take-off (PTO) can be directly connected to the drive system. The generator speed is linearly paired with the mobile crane's travel speed.

[0038] The generator can operate in torque mode. In this mode, the system's control unit determines or sets the torque to match the crane speed, engine power utilization rate, accelerator pedal position, the active gear of the drive gearbox, and / or the allowable charging current of the high-voltage battery. Preferably, the torque is determined based on, or in accordance with, the charge state (SoC) of the high-voltage battery and the battery temperature or system temperature. In this case, consideration may be given to which mode is set, as described below.

[0039] When ABS or the brake control system is active, the generator torque may be set to 0 Nm.

[0040] The generator's torque can be set to positive or negative. The system can transmit the drive output from the generator to the drive system of the mobile crane. That is, the generator can be driven by the engine to charge a high-voltage battery. In another operating mode, the generator can also operate as a motor powered by the high-voltage battery to drive the drive system (drive assist). For example, the generator can function as an augmentation or boost for the internal combustion engine when additional engine output is needed, such as when overtaking or climbing a hill.

[0041] 1.2.2.1. Full or Maximum Charging Mode In "Full or Maximum Charge" mode, the aim is to charge the battery as quickly as possible to the intended or specified fully charged state (SoC) or partially charged state.

[0042] When the crane is not moving, the operator can either disable this mode or switch to another mode.

[0043] In this mode, the drive assist described above is turned off.

[0044] The generator receives power during the acceleration, travel, coasting, and braking of the mobile crane, and operates at the maximum possible torque, as long as the power utilization rate of the internal combustion engine (ICE) is below a certain value that can be specified, for example, less than 90%.

[0045] If the power utilization rate of the internal combustion engine (ICE) for the generator exceeds a certain value, for example 90%, the maximum possible drive output of the mobile crane does not change, but the generator's torque may become 0 Nm or gradually decrease to 0 Nm.

[0046] When the battery reaches its target charge state (SoC), the power take-off PTO is turned off and / or disconnected from the drive system.

[0047] The adaptive regenerative mode can be set arbitrarily by the operator. The operator can, for example, specify the timing or degree of regeneration.

[0048] 1.2.2.2. Eco Charging Mode In "Eco Charging" mode, it is necessary to set a good balance or relationship between the battery charging time and the consumption of the internal combustion engine (ICE).

[0049] In this mode, the aforementioned drive assist is turned off.

[0050] The generator receives power during the coasting and braking of the mobile crane and operates with the maximum possible torque.

[0051] During acceleration and while traveling at a constant speed, the generator operates with low torque (or no torque) and receives only minimal force.

[0052] If the power utilization rate of the internal combustion engine (ICE) for the generator exceeds a certain value, for example 90%, the maximum possible drive output of the mobile crane does not change, but the generator's torque may become 0 Nm or gradually decrease to 0 Nm.

[0053] When the battery reaches its target charge state (SoC), the power take-off PTO is turned off and / or disconnected from the drive system.

[0054] The adaptive regenerative mode can be set arbitrarily by the operator. The operator can, for example, specify the timing or degree of regeneration.

[0055] 1.2.2.3. Drive Pro Balance Mode In "Drive Pro" balance mode, a good balance is established between battery charging time and the maneuverability of the mobile crane. Crane drive responsiveness (elasticity) at medium to high speeds is improved. The system output of the drive system is increased.

[0056] The generator receives power during the acceleration, travel, coasting, and braking of the mobile crane, and operates at the maximum possible torque, as long as the power utilization rate of the internal combustion engine (ICE) is below a certain value that can be specified, for example, less than 90%.

[0057] During acceleration of the mobile crane and while driving at high engine utilization (e.g., over 90%), when the accelerator pedal is pressed to a high degree (e.g., over 90%), the generator functions as an engine, drawing energy from the battery and supplying torque to the drivetrain. However, this function is disabled when driving with cruise control engaged.

[0058] The auxiliary torque supplied to the drivetrain by the generator is determined by the system based on the charge status, system temperature, accelerator pedal position, and utilization rate of the internal combustion engine.

[0059] The maximum drive output of a mobile crane is increased by the generator functioning as an electric motor. If the crane's speed exceeds a certain specified value, for example 84 km / h, the generator's auxiliary torque is reduced to 0 Nm.

[0060] Even when the target charge state (SoC) is reached, the power takeoff PTO is not disabled.

[0061] The system issues a warning when drive assistance is limited, for example, by the charge status (SoC), temperature, or other parameters.

[0062] 2. Crane operation The hydraulic pump (e.g., a variable displacement axial piston) in the hydraulic system of the superstructure of a mobile crane is driven by an electric motor. The electric motor is preferably a high-voltage AC synchronous motor. The variable displacement is controlled by a hydraulic load sensing system. Another embodiment is a constant displacement hydraulic pump in which the required capacity is controlled via the rotational speed of the electric motor.

[0063] During crane operation, for example, the following steps are performed: The engine will shut off if the crane drive is inactive for a specified period of time, for example, 3 seconds, and all hydraulic brakes are in the brake position for a specified period of time, for example, 1 second. If the initial speed is not specified or preserved, and the crane drive is in operation, the engine is brought to a neutral position, for example, at 300 or 500 revolutions per minute, for the purpose of supplying system pressure to release, for example, brakes, operating valves, etc. If an initial speed is specified or preserved, the engine will operate at that speed when the crane drive is in operation. • The speed can be increased or decreased by the operator. The value set by the operator is saved for the current normal operation until the crane is turned off (operating mode is turned off). • Speed ​​can be increased by pedal operation, but not decreased. Speed ​​only increases when the pedal is pressed further than the position corresponding to the current speed (i.e., the pedal position exceeds the current speed). This speed value is not saved; that is, when the pedal is released again, the crane returns to the last saved speed value. The system calculates the maximum battery output available to the engine based on the charge state (SoC), temperature, etc. This determined maximum output is then hydraulically adjusted as needed, including braking capacity, by reducing the settings of individual hydraulic systems when the maximum available battery output is too low (settings being, for example, control instructions from the operator via a joystick). This is primarily done when the operator requires or activates multiple main drive units. • The battery's power utilization rate and remaining power rating are displayed on the crane control system's display (UI = user interface). The automatic speed control system can function as follows: The crane control system (CCS) calculates the required hydraulic output, and from this hydraulic output, the required rotational speed of the electric motor is calculated. This required speed forms the basis for calculating the operation of the electric motor's inverter to activate the electric motor and achieve the calculated required speed change. In other words, the setting value of the crane control system (CCS) is the rotational speed or change in rotational speed of the electric motor required to achieve the specified hydraulic output. The hydraulic pump can, for example, be fully electrically driven (battery and / or external power supply and / or generator) and can be driven by an electric motor at any rotational speed at any time. For example, if the crane is not operating and the crane's drive mechanism is actively braked for 3 seconds, the electric motor will stop. When system pressure should be maintained (i.e., the crane's drive mechanism is operational but no output is required), the electric motor operates at idle speed. The (peak) operation of the electric motor depends on the maximum discharge output of the battery (i.e., it depends on the charge state (SoC), temperature, etc.). • The set values ​​or operator instructions are not implemented on a one-to-one basis, but only according to the battery's peak output capacity (i.e., they may be adjusted).

[0064] 2.1. ECO Diesel ICE Mode This mode is automatically activated when a worker switches to crane operation while the generator is running and charging. This mode can also be activated manually.

[0065] The drive gearbox is switched to neutral with power take-off enabled.

[0066] To operate the generator at an efficient rotational speed, the drive gearbox can be switched to an optimal gear ratio, for example, 16 speeds.

[0067] In this mode, the internal combustion engine (ICE) can be started.

[0068] The crane operates on battery power, and the battery can be optionally recharged using a generator. The battery charge state can be, for example, less than 20% charge (SoC) at the start of operation and more than 90% charge (SoC) at the end of operation.

[0069] When the battery needs recharging, a visual and / or audible signal is emitted. For safety reasons, the internal combustion engine (ICE) will only start after this has been confirmed by a worker. This process may be automated if sufficient safety features are in place.

[0070] If remote control is enabled, the engine can be started. When starting the internal combustion engine (ICE) is required, a warning signal, such as a beep, is emitted.

[0071] When the control system is operated from the operator's cab, the internal combustion engine continues to run, and the generator is set to a lower torque or 0 Nm.

[0072] 2.2. Battery Mode In battery mode, the internal combustion engine (ICE) cannot be started.

[0073] If the battery charge level (SoC) falls below a specified first threshold, for example, 15%, a visual and / or auditory warning is issued to the operator. Subsequently, the system output is reduced, but the mobile crane remains fully functional.

[0074] If the battery charge level (SoC) falls below a specified second threshold, for example 8%, a second warning is issued. Subsequently, system output is limited; for example, the maximum speed of the electric motor becomes unavailable.

[0075] If the battery charge level (SoC) falls below a specified third threshold, for example, 2%, a further (final) warning is issued. The crane then stops in a stable position. The hydraulics operate only in neutral.

[0076] In the case of remote operation, a warning signal, such as a beep, is emitted to inform the operator that the mobile crane's output has decreased or stopped.

[0077] 2.3. AC or DC Cable Operation Battery Mode In AC or DC cable-operated battery mode, the internal combustion engine (ICE) cannot be started.

[0078] This mode is automatically activated when the (AC or DC) charging cable is connected to the mobile crane.

[0079] Once the battery reaches its maximum charge state (SoC), charging continues with less hysteresis.

[0080] If the battery charge level (SoC) falls below a specified first threshold, for example, 15%, a visual and / or auditory warning is issued. System output is reduced or limited, but the mobile crane remains fully functional.

[0081] If the battery charge level (SoC) falls below a specified second threshold, for example 8%, a second warning is issued. Subsequently, system output is limited; for example, the maximum speed of the electric motor becomes unavailable.

[0082] If the battery charge level (SoC) falls below a specified third threshold, for example, 2%, a further (final) warning is issued. The crane then stops in a stable position. The hydraulics operate only in neutral.

[0083] In the case of remote operation, a warning signal, such as a beep, is emitted to inform the operator that the mobile crane's output has decreased or stopped.

[0084] 2.4. Emergency Operation Mode The emergency operation mode is activated when the high-voltage battery malfunctions, i.e., when the main power supply fails, or when the battery temperature is too low or too high and the crane is unable to function. In this mode, the crane can only operate within a limited range.

[0085] The system can be started and operated without a high-voltage battery. This is supported by a low-voltage (e.g., 24V) onboard mains power supply or a connected charging power supply. For this purpose, the high-voltage system is supplied with the necessary high voltage and pre-charged by a DC / DC transformer. The DC / DC transformer is powered via the crane's 24V onboard mains power supply to enable the generator to operate. Alternatively, the onboard charger OBC is powered via a charging power supply connected to the crane's charging interface. The onboard charger OBC pre-charges the high-voltage system, thereby enabling its operation.

[0086] The drive gearbox is put into neutral with the power take-off (PTO) activated.

[0087] The drive gearbox can be switched to an optimal gear ratio, such as 16 speeds, to operate the generator at an efficient speed.

[0088] The crane can operate stably if supported or powered by a generator with limited output rather than a high-voltage battery. Starting up individual crane functions takes time and reduces travel speed. Therefore, while all crane functions are usable, they are subject to output limitations and / or startup limitations.

[0089] It is preferable that the mobile crane can transition to a stable state.

[0090] The emergency operation mode is also used by the thermal management system operating in this mode to heat or cool high-voltage batteries that have become inoperable or disabled due to excessively low or high temperatures. This ensures that the battery temperature is kept within the operating temperature range required for crane operation. [Explanation of Symbols]

[0091] Battery system consisting of individual lithium-ion battery packs, including a battery management system and cooling circuit. Battery pump, electric cooling water pump for battery circuits Carrier for crane CCS is a claim control system found in typical diesel-hydraulic cranes. CDM Carrier Display Charger: Onboard charger converting AC three-phase to DC high voltage (connects to an external AC main power supply) Compressor, Coolant High-Voltage Compressor for Air Conditioning Units in Superstructure Interface: An interface for connecting a DC high-voltage main power supply to an external DC fast charger. DC / DC bidirectional transformer from high DC voltage to low DC voltage Generator: High-voltage permanent magnet synchronous motor as a generator HVDU High Voltage Distribution Unit (Distribution Unit and Safety Unit) ICE diesel engine High-voltage inverter for driving an inverter engine or generator. LVDU Low Voltage Distribution Unit Motor: High-voltage permanent magnet synchronous motor ODM Superstructure Display Power takeoff on the PTO drive gearbox SCU Additional controller for high-voltage systems Slip rings: Slip ring bodies that transmit high voltage, low voltage, signals, and CAN bus. SoC (high-voltage battery) charge status Superstructure of a crane TMS Thermal Management System

Claims

1. A method for charging the battery of a mobile crane equipped with an internal combustion engine while the crane is in motion, wherein the energy of the internal combustion engine is used for the movement of the mobile crane and for charging the battery of the mobile crane by a generator. The desired state of charge (SoC) of the battery when the mobile crane arrives at its destination is defined. The charging power rating required by the internal combustion engine for charging the battery is calculated and supplied to the generator. The battery is charged from its current charge state so that a desirable charge state of the battery is available at the calculated arrival time of the mobile crane. method.

2. The desired state of charge (SoC) of the battery when the mobile crane arrives at its destination is 80%, 90%, or 100%. The method according to claim 1.

3. A method for operating a crane equipped with at least one high-voltage battery storage system in emergency operation mode, The aforementioned high-voltage energy storage system may not function or may not function optimally if, for example, the battery temperature is too low or too high. The aforementioned high-voltage system is The high-voltage system is pre-charged by an external power supply that provides power to the low-voltage system and / or onboard charger (crane-mounted charger), following a DC-DC transformation (DC-DC) necessary for the operation of the high-voltage system. For this purpose, the high-voltage battery is operated without activation. method.

4. The high-voltage battery is heated or cooled by the high-voltage thermal management system after the high-voltage system has been pre-charged and operated without being connected to the high-voltage battery. The high-voltage system is supplied with the necessary energy either via a crane-internal generator driven by an internal combustion engine, or via an external power supply connected to a crane charger (onboard charger). The method according to claim 3.

5. It is a mobile crane, Battery and A generator capable of charging the aforementioned battery, An internal combustion engine capable of driving the generator and moving the mobile crane, Equipped with, A control unit that performs the method according to any one of claims 1 to 4, Mobile crane.

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