Mains-powered material handling and / or construction machine

Abstract

Material handling and / or construction machine, in particular lifting equipment such as a crane, comprising a plurality of electric drives (11, 12, 13) for driving working assemblies (4, 6) and / or structural components (3) of the material handling and / or construction machine, a control apparatus for controlling the drives and a power supply device (10) for supplying electrical power to the electric drives, wherein the power supply device has a network connection (14) for connecting to an electrical network and drawing electrical power from the electrical network, wherein a measuring device (16) is provided for measuring the total electrical power consumption of the material handling and / or construction machine from the electrical network (15) at the network connection at the end of the machine.

Description

[0001] The present invention relates to a mains-powered material handling and / or construction machine, in particular in the form of a crane such as a tower crane or other lifting equipment, with several electric drives for driving working units and / or structural parts of the material handling and / or construction machine, a control device for controlling the drives, and a power supply unit for supplying the electric drives with electrical energy, wherein the power supply unit has a mains connection for connecting to a power grid and supplying the electric drives from the power grid.

[0002] Cranes, such as tower cranes, have long been connected to the power grid available at their respective installation sites to supply their electric drives, such as the hoist drive, slewing drive, trolley drive, and, if applicable, luffing jib drive, with electrical energy. The crane has a grid connection for this purpose, allowing it to connect to the power grid and supply its electric drives with power from the grid (see DE 10 2010 063 911 A1 and DE 10 2015 008 038 A1). Various other construction machines, such as concrete pumps or material handling machines in general, such as earthmoving machines like excavators or lifting equipment like cable excavators, also frequently have electric drives, but these are powered by a diesel-electric generator driven by a diesel engine.Even for mobile work machines that currently have diesel-electric drive concepts, the aim is to power the electric drives from a grid connection in order to operate locally emission-free and to always use the machine's grid connection wherever one is available; see also US 4 358 719 A, DE 10 2017 222 949 A1, CA 2 142 532 A1, DE 11 2013 001 281 T5, DE 10 2015 225 910 A1 and WO 2022 / 033982 A1.

[0003] A fundamental requirement for such a power supply system is the ability to provide the crane, material handling machine, and / or construction equipment with a reliable and frequent electrical supply, thereby maximizing customer benefit. Ideally, the machine should be able to be connected to the existing local power supply using a plug-and-play module, without requiring any modifications or extensive preparations each time.

[0004] One problem is that mobile machinery such as cranes or other material handling and / or construction equipment is connected to different power grids at different locations, which provide varying power outputs and are configured differently locally. This leads to problems because a particular crane cannot be set up if the locally available power grid does not provide the necessary power or if the material handling and / or construction equipment would overload the local power grid.

[0005] External power supply inherently requires a grid capacity that is at least equal to, but preferably greater than, the maximum power consumption of the material handling and / or construction machine. This ensures a reliable power supply even when all drives of the machine are in operation and prevents overloading the power grid. To protect against this, the grid connections are sometimes protected by circuit breakers to prevent at least grid overload. However, this is complex and also affects the operation of the machine connected to the grid.

[0006] The present invention is based on the objective of creating an improved material handling and / or construction machine that avoids the disadvantages of the prior art and advantageously develops the latter further. In particular, it aims to enable a simple and safe electrical supply for the material handling and / or construction machine from various types of power grids, taking into account and optimally utilizing the available grid capacity without overloading the grid or the power line, or requiring the grid to be equipped with complex circuit breakers.

[0007] According to the invention, the aforementioned problem is solved by a material handling and / or construction machine according to claim 1. Preferred embodiments of the invention are the subject of the dependent claims.

[0008] It is therefore proposed to measure the total power consumption of the crane and to control and adapt it to the power grid to which the material handling and / or construction machine is connected. According to the invention, the material handling and / or construction machine has a measuring device for measuring the total electrical power consumption from the power grid at the machine's main power connection. With such a measuring device, the actual power drawn directly from the power supply by the machine is always known in real time, so that the load on the supplying power grid is always known accurately and up-to-date.

[0009] The measurement signal from the aforementioned measuring device, which indicates the machine's total power consumption at its mains connection, can be used advantageously in various ways. For example, a display in the operator's cab can show the current power consumption. In particular, however, the measurement signal can also be provided to the control unit of the material handling and / or construction machine to automatically or semi-automatically take measures to prevent overloading the power grid. This allows the material handling and / or construction machine to be operated even on grids that inherently provide less power than the machine normally requires or requires when operating at maximum power.

[0010] According to the invention, the control device is designed to compare the measured total electrical power consumption with the maximum power available from the power grid and, depending on this comparison, to reduce the power consumption of one or more electric drives. If the measuring device detects that the total electrical power consumption of the material handling and / or construction machine is approaching or even reaching the maximum power available from the power grid, the control device limits the power consumption of one or more electric drives to prevent the total power consumption of the machine from increasing further and overloading the connected power grid.

[0011] Such a reduction or limitation of power can be implemented by the control device in various ways. For example, the control device can reduce and / or limit the actuating speed(s) of one or more drives in order to reduce or limit the power consumption at the respective drives when the measured total power consumption of the machine approaches, reaches, or even exceeds the available mains power.

[0012] According to the invention, the control device is designed to scale or rescale control commands for controlling the electric drives, which are entered by a machine operator via input devices such as joysticks, sliders, regulators, or rotary knobs, or specified by an automatic motion control system, depending on the aforementioned comparison of the measured power consumption at the mains connection with the available mains power, and to limit them to a predetermined value that is reduced compared to the maximum possible control command value. For example, if the machine operator specifies a desired movement at maximum speed by tilting the joystick, such as raising the load hook of a crane at maximum lifting speed, the control device can be designed to adjust the said control command "movement" or "movement" to a predetermined value that is lower than the maximum possible value."Lifting at maximum positioning speed" to a lower control command of, for example, 75% of the maximum positioning speed, and thus override the control command specified by the machine operator or the automated control module, so that only a reduced control signal is given to the electric drive.

[0013] The control device can be configured to provide a uniform power reduction for all existing or currently operating electric drives, for example, to limit the positioning speed of all electric drives to a predetermined fraction of their maximum positioning speed when the total power consumption measured by the measuring device at the mains connection reaches, approaches, or even exceeds the available mains power. Alternatively, instead of such a uniform power reduction for all drives, the control device can also be configured to provide different power-reducing measures for different drives, for example, reducing the hoist of a crane to 75% of its maximum positioning speed and imposing no or a lower, or possibly even a lower, power reduction on the crane's slewing mechanism and / or trolley.It may also provide for a stronger speed limit or reduction. For example, the control device may provide a stronger power reduction or limitation for a drive that has a high power consumption, and a smaller or no power reduction or limitation for another drive that has a comparatively lower power consumption.

[0014] Alternatively or in addition to reducing or limiting the power output of one or more drives, the control device can, depending on the comparison between the measured power consumption at the machine's mains connection and the available mains power, also activate an energy storage system and / or increase the power drawn from the energy storage system to supply the electric drives. For example, the material handling and / or construction machine can have one or more batteries or other energy storage devices, such as capacitors, for storing electrical energy, which can provide electrical energy for the drives in addition to the mains connection.If the measured actual total power consumption of the machine approaches, reaches, or even exceeds the available grid power, the control device can activate the machine's energy storage or increase its power consumption in order to reduce or limit the load on the power grid.

[0015] The control device can prioritize power extraction from the grid via the mains connection and only activate the energy storage system or increase the power extraction from it to the extent that the power drawn from the grid does not exceed its available grid capacity or a predetermined level. Alternatively or additionally, the control device can also consider the state of charge of the energy storage system to reduce electricity consumption from the grid and / or ensure efficient use of the stored energy. For example, if the energy storage system has a predetermined charge level or if the charge level exceeds a certain threshold, the control device can activate the energy storage system or deactivate it.The power draw from this source can be increased even if the machine's total power consumption does not yet reach or approach the maximum available grid power. Such priority power draw from the energy storage system can be useful, for example, when the amount of energy stored in a capacitor reaches a predetermined level that makes reusing the stored energy worthwhile.

[0016] To simplify connecting the machine to different power grids, the control device, in a further development of the invention, can have an input interface via which the maximum power available from the respective power grid to be connected can be entered. The control device can then use the maximum grid power provided via the input interface for the aforementioned comparison with the measurement signal from the measuring device, which indicates the actual, total power consumption of the machine.

[0017] The aforementioned input interface can be connected to a manual input device such as a touchscreen or a speech recognition system, via which a machine operator or a setup technician can manually enter the power rating of the respective power grid to be connected.

[0018] Alternatively or additionally, automated input is also possible if the power grid provides an identifier indicating the maximum grid power. In this case, the machine's control device can read this identifier and use it as the basis for comparing the measurement signal from the measuring device.

[0019] To avoid the need for special safety measures on the power grid side when connecting the material handling and / or construction machine to the power grid, a further aspect of the present invention allows for the provision of a circuit breaker at the machine-side power connection. This circuit breaker is designed to interrupt the connection to the power grid when the total power consumption of the machine reaches the maximum available power of the power grid or a specific, appropriately matched level. In particular, the rated residual current at which the circuit breaker trips is adapted to the power grid, especially its maximum available power.

[0020] The aforementioned protective device can, in particular, include an all-current sensitive residual current device (RCD) installed near the machine's mains connection in such a way that the entire power drawn from the machine via the mains connection passes through this RCD. If the actual total power consumption of the machine reaches the level of the rated residual current of the RCD, the latter trips and disconnects the machine from the mains.

[0021] Advantageously, the circuit breaker can be designed with an adjustable rated residual current, at which point the circuit breaker trips, in order to adapt it to the specific power grid being connected when the machine is connected to different power grids. For example, the rated residual current can be adjusted depending on the maximum network power input via the aforementioned input interface, preferably via the machine's control device, which is provided with the maximum network power of the power grid to be connected for the described comparison with the measured actual power consumption.

[0022] Alternatively or additionally, an alternatively configured circuit breaker can simply be installed at the machine's mains connection, which is adapted to the mains supply to be connected in terms of its rated residual current.

[0023] The invention is explained in more detail below with reference to a preferred embodiment and associated drawings. In the drawings show: Fig. 1: a material handling and / or construction machine in the form of a tower crane according to an advantageous embodiment of the invention, which can be connected to a power grid present on a construction site via a mains connection, and Fig. 2: a circuit diagram of the mains connection of the material handling and / or construction machine made of Fig. 1 , which shows the measuring device provided at the mains connection and the all-current sensitive residual current circuit breaker provided there.

[0024] How Fig. 1 As shown, the material handling and / or construction machine 1 can be designed as a crane, in particular a tower crane, which includes as structural components a tower 2 and a boom 3 supported by it, which can be held by a bracing system and balanced by a ballast weight on a counter boom.

[0025] The material handling and / or construction machine 1 comprises several electric drives 11, 12 and 13, which in the case of a crane may be a slewing drive 11, a trolley drive 12 and a hoist drive 13. How Fig. 1 As shown, a trolley 4 can be movably mounted on the said boom 3, which can be moved along the boom 3 by the said trolley drive 12, wherein the trolley drive 12 can include an electric motor that can wind and unwind a trolley cable on a winch or drive it in the manner of a capstan winch.

[0026] A lifting rope 6 can run from the aforementioned trolley 4, carrying a load-handling device such as a load hook 7. The hoist drive 13 can wind and unwind the aforementioned lifting rope 6 on a winch and includes an electric motor for driving the winch.

[0027] The boom 3 can also be driven rotationally about an upright axis, in particular the longitudinal axis of the tower, by the slewing drive 11. When configured as a top-slewing tower, the boom 3 can be rotated relative to the tower 2, while in a bottom-slewing tower, the boom 3 rotates together with the tower 2 about the aforementioned upright axis 4.

[0028] The aforementioned electric drives, in the form of slewing, trolley, and hoist drives 11, 12, and 13, are controlled by a control device 8, which may be electronic and include a microprocessor and a program memory connected to it. The control device 8 can, in particular, execute control commands that a crane operator in the operator's cab 9 can input via suitable input devices such as joysticks and the like.

[0029] An energy supply facility 10 for supplying the aforementioned electric drives 11, 12, 13 with electrical energy comprises a grid connection 14 through which the material handling and / or construction machine 1 can obtain electrical energy from a power grid 15, which supplies the spatial area of ​​a respective construction site or installation site or operating location and may, for example, be the supply network of the respective utility company.

[0030] The aforementioned mains connection 14 may in particular include a multi-pole mains plug which can be connected to a socket or a complementary connector of the power grid 15.

[0031] At the mains connection 14 or at a point in the machine-side circuit through which the entire power consumption of the material handling and / or construction machine 1 flows from the mains connection 14, the material handling and / or construction machine 1 has a measuring device 16 for measuring the total electrical power consumption from the mains 15, cf. Fig. 1 and Fig. 2 In the case of the typically multi-pole, for example four-pole, design of the network connection line 17, the measuring device 16 can be connected to the conductors of the supply line 17, cf. Fig. 2 and measure the total current flow through the mains supply line 7. The measuring device 16 can measure the power consumption in various ways, for example, by measuring the current flow and / or the voltage, and may include suitable measuring modules for this purpose, see [reference]. Fig. 2 .

[0032] Furthermore, a circuit breaker 18 is provided at the mains connection 14 of the material handling and / or construction machine 1, or at the measuring device 16, and / or at a point in the machine-side power network through which the entire power consumption passes. This circuit breaker may include an all-current-sensitive residual current device (RCD). Such an all-current-sensitive RCD 18 may, for example, be four-pole, cf. Fig. 2 , in order to be connected to the four-pole power supply line 17, and may be designed to be converter-proof.

[0033] The measurement signal from the measuring device 16, which indicates the total current power consumption of the machine 1, is advantageously provided to the control device 8, which can compare the total power consumption with a limit value that can be determined depending on the maximum available power of the respective power grid 15, for example, equated to the maximum available grid power or set to a predetermined fraction thereof. This limit value, depending on the maximum available power of the power grid 15, can advantageously be provided via an input interface of the control device 8.

[0034] The control device 8 is advantageously designed to compare the current actual, measured power consumption of the machine 1 with the maximum available power or the specified limit value entered via the input interface, in order to provide, if necessary, a power reduction for the electric drives 11, 12, 13 in the manner described above.

[0035] Alternatively or additionally, the control device 8 can also connect an energy storage device 19 of the power supply unit 10 and / or increase the power draw from such a storage device to prevent overloading the power grid 15. Such an energy storage device 19 can comprise a battery cell and / or a capacitor, or several groups or combinations thereof, and the energy storage device 19 can be provided independently on the material handling and / or construction machine 1. If necessary, a separate energy storage device, for example in the form of a storage container, can also be provided at the machine's installation site and connected to the machine.

Claims

1. Material-handling and / or construction machine, in particular lifting equipment such as a crane, having a plurality of electric drives (11, 12, 13) for driving working assemblies (4, 6) and / or structural components (3) of the material-handling and / or construction machine, a control device (8) for controlling the drives (11, 12, 13), and an energy supply device (10) for supplying the electric drives (11, 12, 13) with electrical energy, wherein the energy supply device (10) has a grid connection (14) for connection to a power grid (15) and for drawing the electrical energy from the power grid (15), as well as a measuring device (16) for measuring the total electrical power consumption of the material-handling and / or construction machine from the power grid (15) at the machine-side grid connection (14), characterized in that the control device (8) is configured to compare the measured total electrical power consumption with a power maximally providable by the power grid and / or a limit value dependent thereon and, depending on this comparison, to limit the power consumption of one or more electric drives (11, 12, 13) and to scale control commands, which were input by a machine operator for controlling the electric drives and / or were generated by a machine control module, depending on said comparison and to limit them to a reduced maximum value.

2. Material-handling and / or construction machine according to the preceding claim, wherein the control device (8) is configured to reduce one or more actuation speeds of one or more electric drives (11, 12, 13) and to override an actuation-speed command that indicates an actuation-speed request exceeding this.

3. Material-handling and / or construction machine according to one of the preceding claims, wherein the control device (8) is configured, depending on said comparison, to switch in an energy supply storage device (19) of the material-handling and / or construction machine and / or to increase the power withdrawal from the energy supply storage device for supplying the electric drives (11, 12, 13) when the measured actual total power consumption of the material-handling and / or construction machine (1) reaches the maximally providable power of the power grid (15) or the limit value derived therefrom or a predetermined fraction thereof.

4. Material-handling and / or construction machine according to one of the preceding claims, wherein the control device (8) has an input interface for inputting the maximally providable power of the respective power grid (15) to be connected.

5. Material-handling and / or construction machine according to one of the preceding claims, wherein a circuit breaker (18), matched to the respective power grid to be connected, is provided on the machine side at the grid connection (14), through which circuit breaker the entire power consumption of the material-handling and / or construction machine (1) drawn from the power grid (15) passes.

6. Material-handling and / or construction machine according to the preceding claim, wherein the circuit breaker (18) comprises a universal-current-sensitive residual-current circuit breaker.

7. Material-handling and / or construction machine according to the preceding claim, wherein the universal-current-sensitive residual-current circuit breaker is of multipole design and is connected to the conductors of the grid supply line (17) of the material-handling and / or construction machine (1).

8. Material-handling machine according to one of the three preceding claims, wherein the circuit breaker (18) is configured to be adjustable with regard to its rated residual current, upon reaching which the circuit breaker (18) trips.

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