WO2023174679A1

WO2023174679A1 - Electrically operated civil engineering machine, and method therefor

Info

Publication number: WO2023174679A1
Application number: PCT/EP2023/055087
Authority: WO
Inventors: Matthias Osterland; Marco Voigt; Rupert HAAS
Original assignee: Bauer Maschinen Gmbh
Priority date: 2022-03-18
Filing date: 2023-03-01
Publication date: 2023-09-21
Also published as: EP4245923B1; EP4245923A1; EP4245923C0; CN118103569A

Abstract

The invention relates to an electrically operated civil engineering machine comprising: a mobile support apparatus; at least one civil engineering tool; at least one electric motor, which is designed to drive an actuation unit in a drive mode and to generate electrical energy in a recuperation mode; at least one internal rechargeable battery unit for storing electrical energy and for providing electrical energy to the at least one electric motor; a supply device for supplying electrical energy from an external energy source in order to electrically operate the civil engineering machine; and a circuit arrangement by means of which the at least one electric motor, the at least one battery unit and the supply device are interconnected by lines. According to the invention, the circuit arrangement has an intermediate circuit with voltage-controlled power regulation and the power regulation is decentralised. Associated in each case with the at least one electric motor, the at least one battery unit and the supply device is a stand-alone regulation component which, in each case independently of a voltage in the intermediate circuit, regulates the supply or release of electrical energy out of or into the intermediate circuit.

Description

ELECTRICALLY OPERATED CIVIL ENGINEERING MACHINE AND METHOD THEREOF

The invention relates to an electrically operated civil engineering machine with a mobile carrier device, at least one civil engineering tool, at least one electric motor, which is designed both to drive an actuation unit in a drive mode and to generate electrical energy in a recuperation mode, at least one internal rechargeable battery unit for storing electrical energy and for supplying the at least one electric motor with electrical energy, a supply device for supplying electrical energy from an external energy source for electrically operating the civil engineering machine and a circuit arrangement through which the at least one electric motor, the at least one battery unit and the supply device are connected to one another by cables, according to the preamble of claim 1.

The invention further relates to a method for electrically operating a civil engineering machine with a mobile carrier device, at least one civil engineering tool, at least one electric motor, which is designed both to drive an actuating unit in a drive mode and to generate electrical energy in a recuperation mode, at least one internal rechargeable Battery unit for storing electrical energy and for supplying the at least one electric motor with electrical energy, a supply device for supplying electrical energy from an external energy source and a circuit arrangement through which the at least one electric motor, the at least one battery unit and the supply device are connected to one another by line, according to the preamble of claim 10. Purely electrically driven civil engineering machines have been known for a long time and are used in particular at work locations where noise, vibrations and exhaust gases are undesirable, such as those that occur to an increased extent in civil engineering machines powered by internal combustion engines. Due to the high energy requirement of such electrically operated civil engineering machines, they have a supply device for supplying electrical energy from an external electrical energy source, which is also referred to as a power source, in particular an electrical power network. This requires the provision of an appropriate electrical line.

Furthermore, electrically operated civil engineering machines are also provided with a rechargeable battery unit, which serves in particular to supply the mobile civil engineering machine with sufficient electrical energy when moving or moving in which the electrical line connection is often disconnected.

The storage of electrical energy in an internal battery unit also allows, in the event of energy consumption peaks of the civil engineering machine, which cannot be completely supplied by the normal energy supply via the supply device from the connected external power network, additional electrical energy from the internal battery unit to cover the peak energy requirements can be retrieved.

It is also known to design electric motors provided on a civil engineering machine in such a way that they can also be operated in a recuperative manner to recover energy. In particular when operating cable winches, with which loads can be raised and lowered, for example vertically or at an angle, the positional energy of the load can be converted back into electrical energy when lowering using an electric motor in recuperation mode. This reduces the energy requirements of the civil engineering machine and makes operation more economical and environmentally friendly overall.

For efficient operation of the civil engineering machine, demand-based control and distribution of the energy on the civil engineering machine is essential. Basically, as with electrically powered vehicles, it is common practice Particularly in motor vehicles with recuperatively operated electric motors, energy distribution can be achieved through a central control system. Values for the energy requirements of the individual electrical consumers are transmitted to a central computer via appropriate sensors, with the computer then controlling energy provision via the supply device and the battery unit.

When operating a civil engineering machine, large load changes can occur, which lead to short-term increased energy consumption or to short-term amounts of energy that are generated recuperatively.

The invention is based on the task of providing an electrically operated civil engineering machine and a method for operating it, with which a particularly economical and efficient operation of the civil engineering machine is possible.

The task is solved on the one hand by a civil engineering machine with the features of claim 1 and on the other hand by a method with the features of claim 10. Preferred embodiments of the invention are set out in the dependent claims.

The civil engineering machine according to the invention is characterized in that the circuit arrangement has an intermediate circuit with voltage-controlled power control and that the power control is implemented decentrally, with the at least one electric motor, the at least one battery unit and the feed device being assigned an independent control component, each of which is dependent on a voltage in the intermediate circuit regulates the supply or release of electrical energy from or into the intermediate circuit. The intermediate circuit can be an electrical conductor, in particular a busbar.

A basic idea of the invention is to rely on a central controller for power regulation or power management. This is achieved by providing a circuit arrangement with an intermediate circuit with voltage-controlled power control. An independent control component is assigned to the at least one electric motor, the at least one battery unit and the feed device. This control component is not controlled by a central controller. Rather, the individual independent control components depend on one measured in the intermediate circuit Voltage from each control component independently supplies energy to the DC link or removes energy from the DC link. This decentralized power control allows the system as a whole to react very quickly to load changes with a sudden increase or decrease in energy demand. Even large quantities of recuperatively generated energy that are available at short notice can be transferred to electrical consumers, the internal battery unit or, if necessary, to the external power grid if this is possible.

In principle, the respective control components can be provided at a suitable position. According to a further development of the invention, it is particularly preferred that the control components are interposed between the intermediate circuit and the respectively assigned electric motor, the assigned battery unit or the assigned feed device. The control components can receive values for the current voltage in the intermediate circuit directly or via a corresponding measuring element. Each control component is provided with a regulation or control logic, through which it is specified that energy is supplied to the intermediate circuit or removed from the intermediate circuit at a certain voltage value or at a certain time profile of the voltage values in the intermediate circuit, in order to, for example, electric motors or other electrical consumers as required to supply the required energy or, if necessary, to supply energy generated in a recuperation operation to the battery unit for storage.

A further preferred embodiment of the invention is that an excess energy consumption unit, in particular a brake chopper and/or an electrical consumer, is provided with an independent control component and is connected to the intermediate circuit. Through the excess energy consumption unit, in particular a so-called brake chopper, excess energy from recuperation, which is not needed and cannot be stored, can be converted, in particular, into heat. If the heat cannot be used to heat the driver's cab, for example, it can be released into the environment. This can prevent overloading of the electrical system of the civil engineering machine and also the internal battery unit. In particular, the service life of a battery unit can be significantly affected. If too much energy is supplied to the battery unit in too short a time. Excess energy can also be fed to another electrical consumer in order to avoid overvoltage peaks.

The intermediate circuit can basically be designed in any suitable way. According to one embodiment of the invention, it is particularly advantageous that the intermediate circuit is designed to conduct and distribute energy on a direct current basis. An intermediate circuit for conducting direct current allows particularly good and fast energy distribution.

Particularly when conducting and distributing the energy in the intermediate circuit as direct current, according to an embodiment variant of the invention, it is advantageous that at least one control component comprises a DC/DC controller. Preferably, several or all control components can have a DC/DC controller. Such an actuator can be used to convert a DC voltage supplied to an input into a DC voltage with a higher, lower or inverted voltage level. Such DC/DC controllers are in particular self-commutated power converters.

When obtaining electrical energy from an external alternating current network, it is advantageous according to a further development of the invention that the supply device is designed to supply electrical energy from an alternating current source, with a current rectifier unit being provided on the supply device. This can in particular be a rectifier through which an alternating current or an alternating voltage can be converted into a direct current or a direct voltage.

A further advantageous embodiment of the invention is that the at least one electric motor is assigned an inverter unit, which is designed to convert direct current or voltage into alternating current or voltage and vice versa. The inverter unit therefore also represents a rectifier or inverter, which can convert current and voltage in both directions. On the one hand, direct current from the intermediate circuit can be supplied to the electric motor as alternating current, while on the other hand, electrical energy generated in a recuperation operation of the electric motor can be of a An alternating current can be converted into a direct current for delivery to the intermediate circuit. When explaining the invention, reference is usually made to alternating and direct current. In principle, alternating current and direct voltage could also be referred to here, since alternating current usually only occurs with alternating voltage and direct current only occurs with direct voltage.

The actuation unit, which is driven by the electric motor, which can also be operated in a recuperative manner, can be any actuation unit on the civil engineering machine that releases energy during a braking process or a lowering process or similar. This energy can be used to operate the electric motor in recuperation mode, so that this kinetic and/or positional energy can be converted into electrical energy.

According to a preferred embodiment of the invention, it is provided that this is designed as a drilling device and that the at least one electric motor drives a power turret and / or a cable winch or any other consumer such as. B. a hydraulic pump. The drilling device can in particular be an earth drilling device, which can be used, for example, to create foundation piles in the ground. In particular, on such a drilling device, especially when it is used for discontinuous drilling, for example with a drilling bucket, the drilling tool is raised and lowered frequently. Especially when lowering, an electric motor on the associated cable winch can regularly convert positional energy into electrical energy. This can significantly improve the energy efficiency of a civil engineering machine. Furthermore, it is advantageous if at least two electric motors are provided.

The method according to the invention is characterized in that the circuit arrangement has an intermediate circuit with voltage-controlled power control, that the power control is carried out decentrally, with an independent control component being assigned to the at least one electric motor, the at least one battery unit and the feed device, and that through the independent control component Electrical energy from the at least one electric motor, which is released into the intermediate circuit with the at least one battery unit and the feed device depending on a voltage in the intermediate circuit or is supplied to it from the intermediate circuit. The method can be used in particular in the civil engineering machine according to the invention described above. The advantages described above can be achieved.

A preferred method variant of the invention is that excess electrical energy, which cannot be used to operate the civil engineering machine and to charge the batteries, is fed to an excess energy consumption unit, in particular a brake chopper. In recuperation mode, a large amount of electrical energy can be generated at short notice, particularly when lowering heavy loads. Supplying too much electrical energy to the battery pack may result in damage to the battery pack or a significant reduction in the life of the battery pack. In such a case, it is expedient to supply unusable excess energy to a corresponding consumption unit, in particular a so-called brake chopper. This can consume and break down the excess energy, for example by converting it into heat. The heat can be released into the environment unless it can be used for other purposes. Basically, energy consumption by the brake chopper is a measure that should be avoided if possible and only used when necessary. In principle, the construction machine can be operated in such a way that the energy generated is used in the battery unit or by electrical consumers and/or a power supply is controlled, for example by lowering a cable winch, in such a way that a lowering speed is reduced and the energy generated is reduced over a longer period of time is distributed.

A particularly good and fast energy distribution in the system can be achieved according to a method variant by conducting and distributing the electrical energy as direct current in the intermediate circuit.

According to a further method variant, it is preferred that electrical energy is supplied as alternating current from the external energy source via the supply device, with a current rectifier unit being arranged on the supply device, through which the alternating current is converted into direct current. Corresponding converter units can also be provided on the control components, so that it is ensured that the desired type of current, especially In particular, a direct current is supplied or removed and the desired voltage level is adjusted.

In a corresponding manner, according to a further development of the invention, it is preferred that the at least one electric motor is assigned an inverter unit, through which the direct current from the intermediate circuit is converted into alternating current in the drive mode and, conversely, an alternating current generated by the electric motor in the recuperation mode is converted into direct current. In this case, the supply and removal of electrical energy into or out of the intermediate circuit occurs exclusively as direct current. If necessary, a corresponding conversion into alternating current or from alternating current is provided. This enables reliable and fast energy distribution.

The invention is further explained below using preferred exemplary embodiments, which are shown schematically in the drawings. Shown in the drawings:

Fig. 1 is a side view of a civil engineering machine according to the invention; and

Fig. 2 is a schematic representation of a circuit arrangement according to the invention with possible components.

A civil engineering machine 10 according to the invention with a carrier device 12 is shown in FIG. The carrier device 12 includes a crawler chassis as an undercarriage 14, on which a superstructure 16 is rotatably mounted. A control 60 for the civil engineering machine 10 is located in an operating cabin of the superstructure 16. A mast 20 can be adjustably mounted on the superstructure 16 via an articulation mechanism 18, which has a substantially vertical position during operation.

According to the illustrated embodiment, the mast 20 can be designed as a leader 21 with a linear guide 24 on its front. A work carriage 38 with a rotary drilling drive 36 can be mounted so that it can move vertically along the linear guide 24. As a result, the civil engineering machine 10 can be designed as a drilling device. The drawing shows an upper position of the rotary drill drive 36 and a lower position with broken lines. A rope 40 can be guided over a mast head 22 at the upper end of the mast 20, at one end of which a preferably telescopic Kelly rod 32 with an exemplary auger 34 can be provided to form a civil engineering tool 30. The Kelly rod 32 can be guided on the work carriage 38 by a sleeve-shaped drive wheel of the rotary drill drive 36, so that a torque can be transmitted from the rotary drill drive 36 to the Kelly rod 32 via driver strips (not shown). At the lower end of the Kelly rod 32, the auger 34 can be arranged to create a borehole in the ground. The drilling tool can basically be of any design and in particular have a drilling auger 34 or a drilling bucket.

From the Kelly bar 32, the rope 40 can be guided via deflection rollers 26 on the mast head 22 along the mast 20 to a cable winch 46 in the superstructure 16. According to the invention, the cable winch 46 is driven via an electric motor 50, which can also be operated in a recuperation mode. The Kelly rod 32 with the auger 34 can be raised and lowered using the rope 40 via the cable winch 46. When lowering, positional energy can be converted into electrical energy by the electric motor 50 and delivered to an intermediate circuit, which is described in more detail below.

Using an actuator 28 with a winch on the mast 20, the work carriage 38 with the rotary drilling drive 36 can be pulled upwards using another adjusting cable 29. By appropriately driving the actuating drive 28 in the opposite direction, the work carriage 38 can also be lowered downwards with the rotary drilling drive. The rotary drilling drive can be formed by a power turret 36 with at least one further electric motor. The actuator 28 can also be equipped with an electric motor, not shown, which can also be operated in recuperation mode. The work carriage 38 with the rotary drill drive 36 can also be viewed as part of the civil engineering tool 30.

In the exemplary embodiment shown, a force measuring device 62 is preferably arranged on a deflection roller 26 on the mast head 22. The force measuring device 62 can be designed, for example, as a force measuring pin, through which a cable pulling force on the cable 40 can be detected. The force measuring device 62 is connected to the control 60 on the superstructure 16. The at least one electric motor 50 for operating the cable winch 46 and preferably also the further electric motor for operating the actuator 28 designed as a winch are controlled via the controller 60. The electric motor 50 can be controlled by the controller 60.

2 shows schematically a circuit arrangement 70 according to the invention with an intermediate circuit 72, which is designed in particular as a direct current-operated DC link, for example with a defined voltage of, for example, 750 volts. The intermediate circuit 72 can be connected as an essential energy supply to a supply device 80, which is connected to an energy source 82 via a detachable connection 81. The energy source 82 can in particular be an alternating current network.

For further energy supply, the intermediate circuit 72 is connected to at least one further battery unit 58, which can be recharged. The at least one battery unit 58 can be charged via the intermediate circuit 72. For this purpose, energy from the external energy source 82 or electrical energy generated recuperatively on the civil engineering machine 10 can be used.

2 also shows schematically at least one electric motor 50, which can raise and lower a schematically indicated civil engineering tool 30 along a mast via the cable winch, not shown in FIG. 2. For lifting, the electric motor 50 is supplied with electrical energy from the intermediate circuit 72 to drive the cable winch.

Furthermore, when the tool device 30 is lowered in a recuperation mode of the electric motor 50, positional energy can be converted into electrical energy. This electrical energy from the electric motor 50 is supplied to the intermediate circuit 72 via an intermediate inverter unit 52, which can convert alternating current into direct current and vice versa. This electrical energy can be supplied from the intermediate circuit 72 to the at least one battery unit 58 or at least one further electrical consumer 64. The internal battery unit 58 can in principle be designed to be replaceable, in particular as a removable battery. The further electrical consumer can also be an electric motor, a heating coil or another electrically operated component. According to the invention, the supply and removal of electrical energy are not controlled via a central control. Rather, the feed device 80, the at least one battery unit 58, the electric motor 50 as well as the at least one electrical consumer 64 and a brake chopper 66 to be described are each assigned an independent control component. This can be installed directly in the respective unit. A voltage in the intermediate circuit 72 can be detected by the control component. Depending on a stored control logic in each control component, electrical energy can be supplied or removed depending on the current voltage value in the intermediate circuit 72 or a curve of the voltage value. This means that, compared to a central control system, there can be a quicker response to sharply increasing energy consumption or high amounts of energy that arise at short notice.

If electrical energy, which is generated recuperatively, cannot be stored in the at least one battery unit 58 in the circuit arrangement 70 or supplied to another component for use, this excess energy can be fed to a brake chopper 66, which, for example, represents an excess energy consumption unit. For example, it converts this excess energy into heat.

In addition, the supply device 80 can also be assigned an inverter unit, particularly in the case of obtaining alternating current from the external energy source 82. This ensures that only direct current is supplied to the intermediate circuit 72 in the exemplary embodiment shown.

Claims

PATENT CLAIMS

1 . Electrically operated civil engineering machine (10).

- a mobile carrier device (12),

- at least one civil engineering tool (30),

- at least one electric motor (50), which is designed both to drive an actuation unit in a drive mode and to generate electrical energy in a recuperation mode,

- at least one internal rechargeable battery unit (58) for storing electrical energy and for supplying the at least one electric motor (50) with electrical energy,

- a supply device (80) for supplying electrical energy from an external energy source (82) for electrically operating the civil engineering machine (10) and

- a circuit arrangement (70), through which the at least one electric motor (50), the at least one battery unit (58) and the feed device (80) are connected to one another by cables, thereby marked,

- that the circuit arrangement (70) has an intermediate circuit (72) with voltage-controlled power control and

- that the power control is carried out decentrally, with an independent control component being assigned to the at least one electric motor (50), the at least one battery unit (58) and the feed device (80), each of which supplies a feed depending on a voltage in the intermediate circuit (72). or output of electrical energy from or into the intermediate circuit (72). Electrically operated civil engineering machine (10) according to claim 1, characterized in that the control components are interposed between the intermediate circuit (72) and the respectively assigned electric motor (50), the assigned battery unit (58) or the assigned feed device (80). Electrically operated civil engineering machine (10) according to claim 1 or 2, characterized in that an excess energy consumption unit, in particular a brake chopper (66) and/or an electrical consumer (64), is provided with an independent control component and is connected to the intermediate circuit (72). is. Electrically operated civil engineering machine (10) according to one of claims 1 to 3, characterized in that the intermediate circuit (72) is designed to conduct and distribute direct current. Electrically operated civil engineering machine (10) according to one of claims 1 to 4, characterized in that at least one control component comprises a DC/DC controller. Electrically operated civil engineering machine (10) according to one of claims 1 to 5, characterized in that the supply device (80) is designed to supply electrical energy from an alternating current source, a current rectifier unit being arranged on the supply device (80). Electrically operated civil engineering machine (10) according to one of claims 1 to 6, characterized in that the at least one electric motor (50) is assigned an inverter unit (52), which is designed to convert direct current into alternating current and vice versa. Electrically operated civil engineering machine (10) according to one of claims 1 to 7, characterized in that it is designed as a drilling device and that the at least one electric motor (50) drives a power turret (36) and / or a cable winch (46). Electrically operated civil engineering machine (10) according to one of claims 1 to 8, characterized in that at least two electric motors (50) are provided. Method for electrically operating a civil engineering machine (10), in particular according to one of claims 1 to 9

- a mobile carrier device (12),

- at least one civil engineering tool (30),

- a supply device (80) for supplying electrical energy from an external energy source (82) and

- that the circuit arrangement (70) has an intermediate circuit (72) with voltage-controlled power control,

- that the power control is carried out decentrally, with an independent control component being assigned to the at least one electric motor (50), the at least one battery unit (58) and the feed device (80), and

- that the independent control component provides electrical energy from the at least one electric motor (50), the at least one battery unit (58) and the feed device (80) are each delivered into the intermediate circuit (72) depending on a voltage in the intermediate circuit (72) or fed to it from the intermediate circuit (72). Method according to claim 10, characterized in that excess electrical energy, which cannot be used to operate the civil engineering machine (10) and to charge the battery unit (58), is fed to an excess energy consumption unit, in particular a brake chopper (66). Method according to claim 10 or characterized in that the electrical energy is conducted and distributed as direct current in the intermediate circuit (72). Method according to one of claims 10 to 12, characterized in that electrical energy is supplied as alternating current from the external energy source (82) via the supply device (80), a current rectifier unit being arranged on the supply device (80), through which the alternating current is fed into Direct current is converted. Method according to claim 12 or 13, characterized in that the at least one electric motor (50) is assigned an inverter unit, through which the direct current from the intermediate circuit (72) is converted into alternating current in the drive mode and, conversely, one generated by the electric motor (50) in the recuperation mode Alternating current can be converted into direct current.