Mobile loading machine, in particular loading excavator, and methods for its operation

Abstract

Mobile electrically driven charging machine (1), with at least one electric motor (15) which, in mains operation, draws electrical energy from a mains connection (12), wherein at least one high-voltage energy storage device (18) is arranged on the charging machine (1), which, in battery operation, supplies the at least one electric motor (15) with electrical energy, characterized in that the at least one high-voltage energy storage device (18) feeds a DC intermediate circuit (20) which is connected via an inverter (21) via a mains filter (22) to a three-phase network (13), which connects at least one electric motor (15) to the three-phase network (13), the electric motor (15) is connected to the three-phase network (13) on the AC side of the inverter (21), the mains connection (12) is connected to the three-phase network (13), and the inverter (21) is controlled via a controller (25) in such a way.that the three-phase current generated by the inverter (21) is synchronized with the three-phase current of the grid connection (12), wherein the control unit (25) is connected to the three-phase grid (13) via a measuring unit (24), and the inverter (21) and the grid filter (22) are each bidirectional, and thus electrical energy can be converted and filtered from the DC intermediate circuit (20) to the three-phase grid (13) and from the three-phase grid (13) to the DC intermediate circuit (20).

Description

[0001] The invention relates to a mobile, electrically driven loading machine, in particular a loading excavator, with at least one electric motor that draws electrical energy from a grid connection during mains operation. The invention also relates to a method for operating such a loading machine.

[0002] The German patent application DE 10 2016 106 205 A1 already describes an electrically powered and limitedly mobile material handling machine that is supplied with electrical power via an electrical cable from a power grid. The electrical cable is not wound and unwound via a cable reel mounted on the material handling machine depending on the movement of the material handling machine, but is connected to a current collector trolley that can be moved along a conductor rail located above the material handling machine and defining a corresponding working area. A manual, cable-based power supply is also provided to enable access to the working area, for example, for maintenance purposes.The material handling machine, which can also be referred to as a loading machine, is typically used for handling bulk materials, logs, scrap, or recycled material in halls or outdoor areas. It essentially consists of an undercarriage and a superstructure mounted on the undercarriage so that it can pivot about a vertical axis. Such material handling machines, similar to an excavator, have a boom on the superstructure that can be pivoted by means of a hydraulic lifting cylinder, followed by a pivoting boom extension, a so-called loading arm. A load-handling device, in particular a clamshell grab, is articulated at the outer end of the boom extension.

[0003] Furthermore, a battery-electrically powered and mobile work machine, in particular a wheel loader, is known from German utility model DE 20 2019 105 186 U1. The wheel loader carries a high-voltage energy storage unit, in particular a so-called traction battery, which provides the electrical energy for an electric drive of the wheel loader, other electrical consumers, and a low-voltage intermediate circuit of the wheel loader. The high-voltage energy storage unit is connected to a high-voltage intermediate circuit via a high-voltage distributor. Furthermore, the high-voltage energy storage unit can be directly connected to a corresponding charging device for charging. For driving the wheel loader, at least one first electric motor, in particular an AC or three-phase motor, is provided, which is connected to the high-voltage intermediate circuit via a first power converter.The power converter typically converts the DC voltage of the high-voltage intermediate circuit into AC / three-phase current for the first electric motor. A second electric motor, also an AC or three-phase motor, is also connected to the high-voltage intermediate circuit via another power converter. This second electric motor drives a hydraulic pump for several of the wheel loader's hydraulic drives and, in parallel, a generator that charges a low-voltage battery of the wheel loader's low-voltage electrical system via a charging controller. The low-voltage battery typically has a DC voltage of 12 V or 24 V. The wheel loader's auxiliary electrical devices, such as control systems or lighting systems, are connected to the low-voltage electrical system. Air conditioning components, such as an air conditioning compressor or a fan, are also connected to the high-voltage intermediate circuit.

[0004] The invention is based on the object of improving a mobile, electrically driven loading machine, in particular a loading excavator, and methods for operating such a loading machine.

[0005] This object is achieved by a mobile, electrically driven loading machine, in particular a loading excavator, having the features of claim 1 and a method for operating such a loading machine having the features of claim 12. Advantageous embodiments of the invention are specified in claims 2 to 11 and 13 to 17.

[0006] According to the invention, an improvement is achieved in a mobile, electrically powered loading machine, in particular a loading excavator, with at least one electric motor which draws electrical energy from a grid connection during mains operation by arranging at least one high-voltage energy storage device on the loading machine, which supplies the at least one electric motor with electrical energy during battery operation. The mixed mains and battery operation increases the service life of the high-voltage energy storage devices because the high-voltage energy storage devices are subjected to less load. In addition, the high-voltage energy storage devices can be designed with a lower storage capacity and are therefore smaller and more cost-effective, since part of the operation of the loading machine takes place directly in mains operation. Nevertheless, the location-independent flexibility of a battery-powered loading machine is achieved.

[0007] Advantageously, the at least one high-voltage energy storage device feeds a direct current intermediate circuit which is connected to a three-phase network via an inverter.

[0008] It is structurally advantageous that the at least one electric motor is designed as a three-phase motor, in particular as an asynchronous motor.

[0009] It is particularly advantageous that at least one high-voltage energy storage unit feeds the DC link via a high-voltage distribution box.

[0010] Advantageously, it is provided that the grid connection is connected to the three-phase grid, the inverter is connected to the three-phase grid via a grid filter and the inverter is controlled via a controller such that the three-phase current generated by the inverter is synchronized with the three-phase current of the grid connection, wherein the controller is connected to the three-phase grid via a measuring unit. Accordingly, in battery operation, a three-phase current is generated on the charging machine, via which three-phase current the at least one electric motor is supplied with electrical energy and this three-phase current is synchronized for grid operation with the three-phase current of the power grid, in particular the public power grid. This enables a bidirectional power flow between the three-phase current of the charging machine and thus the high-voltage energy storage device of the charging machine and the power grid, in particular the customer grid or public power grid.For this purpose, the measuring unit measures the three-phase voltage upstream and downstream of a circuit breaker in the three-phase network. This grid synchronization enables peak shaving, i.e., a reduction in the required connected load by smoothing power peaks via at least one high-voltage energy storage device, as well as reactive power compensation on the charging device and feeding power back into the grid.

[0011] For grid synchronization, it is advisable to arrange a circuit breaker between the mains filter and the three-phase network and to use the measuring unit to measure the three-phase voltage of the three-phase current before and after the circuit breaker in order to only switch the circuit breaker when synchronization is achieved via the control system and thus combine the three-phase current converted on the charging machine with the three-phase current from the power grid.

[0012] Because the inverter and line filter are both bidirectional, allowing electrical energy to be converted and filtered from the DC link to the three-phase network, as well as from the three-phase network to the DC link, peak shaving is possible locally on the charging device and also in the connected power grid. Peak shaving in the connected power grid requires an external measuring point in the power grid. Reactive power compensation in the connected power grid is then also possible via the charging device.

[0013] It is also planned that at least one high-voltage energy storage unit, the inverter and the mains filter are tempered by a heat pump and the heat pump is connected to the DC link.

[0014] Particularly advantageously, the at least one high-voltage energy storage unit, the high-voltage distribution box, the inverter, the line filter, and the heat pump are combined modularly into a single energy storage module. This energy storage module can therefore also be used to retrofit mains-powered charging devices. If necessary, existing radiators and coolant pumps can also be assigned to the energy storage module.

[0015] In a manner known per se, the loading machine is provided essentially comprising an undercarriage, an uppercarriage mounted on the undercarriage for pivoting about a vertical axis, a boom mounted on the uppercarriage and pivoting about a first horizontal axis, and a boom extension mounted at an upper end of the boom and pivoting about a second horizontal axis, said boom extension having a load-handling device. The load-handling devices are arranged in an oscillating or rigid manner and are preferably designed as orange peel grabs, clamshell grabs, scrap shears, magnetic plates, sorting grabs with an additional tilting cylinder for alignment, or load hooks. Some load-handling devices, in particular the aforementioned grabs, have an electric or hydraulic drive so that they can rotate about their own axis.

[0016] According to the invention, in connection with a method for operating such a charging machine, it is now possible for the charging machine to be operated either in mains operation or in battery operation, and for three-phase current to be generated on the charging machine in battery operation. In this case, the charging machine is preferably operated predominantly in mains operation.

[0017] It is preferably provided that in mains operation the three-phase current of the charging machine is synchronized with the three-phase current of the power grid.

[0018] This type of energy supply for the charging machine via a grid connection and / or an energy storage module can be advantageously combined with peak shaving, which smooths out peak loads for commercial electricity consumers and contributes to stabilizing the power grid. Peak shaving can be achieved both by feeding power globally into the power grid, in particular the customer grid or public grid, for the respective commercial consumer, but also locally on the charging machine itself, for example by having at least one high-voltage energy storage unit support the charging machine during operation, thus requiring less power to be drawn from the power grid, in particular the public grid.

[0019] A preferred procedure provides that the charging machine is operated in the network operation in parallel with the at least one high-voltage energy storage device in a charging operation.

[0020] Furthermore, it is advantageously provided that, during grid operation, the charging device draws power from both the power grid and the high-voltage energy storage device in parallel with the at least one high-voltage energy storage device. This also allows power to be drawn from the high-voltage energy storage device in support during grid operation (peak shaving).

[0021] The grid synchronization according to the invention makes it possible for the at least one high-voltage energy storage device to supply electrical energy to the power grid via the grid connection as needed during grid operation of the charging machine. An exemplary embodiment of the invention is explained in more detail in the following description. It shows: Fig. 1 a schematic overall view of a loading machine, Fig. 2 a block diagram of the function of the electric charging machine, Fig. 3 a perspective partial view of a charging machine with two high-voltage energy storage units and Fig. 4 a perspective view of an energy storage module of the charging machine according to Fig. 3.

[0022] The Fig. 1 shows a schematic side view of a mobile loading machine 1, in particular a loader excavator. The loading machine 1 essentially consists of an undercarriage 2 and a superstructure 3, which is arranged on the undercarriage 2 so as to be pivotable about a vertical axis. Such loading machines 1, which are also called material handling machines, have, in the manner of an excavator, a boom 4 on the superstructure 3 which can be rotated about a first horizontal axis by means of a hydraulic lifting cylinder and, adjoining this at an upper end, a boom extension 5, the so-called loading arm, which can also be rotated about a second horizontal axis. At the outer end of the boom extension 5, a load-handling device 6, preferably a multi-shell grab, a clamshell grab, a scrap shear, a magnetic plate, a sorting grab with an additional tilting cylinder for alignment, or a load hook, is arranged in an articulated or rigid manner.Some load-handling devices 6, in particular the aforementioned grabs, have an electric or hydraulic drive so that they can rotate around their own axis. Such loading machines 1 are typically used for handling bulk materials, logs, scrap, or recycling material. A driver's cab 7 is also arranged on or attached to the superstructure 3, which can preferably be raised and / or advanced hydraulically in a continuously variable manner.

[0023] The undercarriage 2 comprises a two-axle chassis with a first axle 8 and a second axle 9, with a total of four rubber-tired or pneumatic-tired wheels 10 arranged thereon, which are particularly designed as twin wheels. Typically, the first axle 8 is a steerable front axle and rigidly mounted, whereas the second axle 9 is a rear axle and is suspended in an oscillating manner. By pivoting the uppercarriage 3 by 180 degrees during operation, the current orientation of the driver's cab 7 relative to the direction of travel can be changed. In the area of ​​each of these wheels 10, a support element 11 is arranged for a so-called 2-point or 4-point support, via which the undercarriage 2 can be supported against a surface U during loading operations. A blade (not shown) can also be used on the undercarriage 2 for support. Alternatively, the undercarriage 2 can also be equipped with crawler tracks.

[0024] The Fig. 2 shows a block diagram of the function of the electric charging machine 1 according to the invention, which can be operated either in mains operation or in pure battery operation.

[0025] In grid operation, the loading machine 1 is electrically connected to a power grid, in particular a customer grid or a public grid, via a grid connection 12 via an electrical cable (not shown). The grid connection 12 is thus to be understood as a plug, coupling, or junction box on the undercarriage 2 of the loading machine 1. The electrical cable has a fixed length and is laid on the loading machine 1 for connection. Alternatively, the electrical cable is wound and unwound via a cable reel (not shown) arranged on the loading machine 1, in particular on the undercarriage 2 of the loading machine 1, depending on the movement of the loading machine 1. The grid connection 12 is connected to a three-phase network 13 of the loading machine 1. In the present case, the grid connection 12 supplies three-phase current with a voltage of 400 V, or 480 V in the USA.Electrical consumers of the loading machine 1 are connected to the three-phase network 13. In the present case, a single electric motor 15 is provided, which is arranged in the superstructure 3 and drives a hydraulic pump of a hydraulic system of the loading machine 1. The travel drive of the loading machine 1 is hydraulic but can also be electric with one or more additional electric motors. The same applies to the swivel drive. A heat pump 16 for air conditioning the high-voltage energy storage unit 18 and the power electronics, in particular the inverter 21 and the line filter 22, is connected to the DC intermediate circuit 20. An AC / DC converter (not shown) connected to the three-phase network 13 generates a 24 V DC from the 400 V three-phase current for an on-board power system, in particular a protective extra-low voltage on-board power system, with two 12 V buffer batteries. The AC / DC converter also serves as a charge controller for the buffer batteries (control voltage).Electrical auxiliary consumers of the charging machine 1, such as controls or lighting systems, but also the coolant pumps 17 and the coolers 23 of the energy storage module 26, are connected to the on-board network in the usual way.

[0026] In the Fig. In Figure 2, the electrical consumers are symbolically represented by a single electric motor 15. A charge controller for the vehicle's electrical system can also be connected to the three-phase network 13 as an electrical consumer.

[0027] This electric motor 15 is the main drive of the charging machine 1 and is designed as an asynchronous motor, in this case with 75 kW. Since asynchronous motors require a high inrush current, a soft starter 14 is connected upstream of the electric motor 15, which limits the inrush current. The asynchronous motor always runs synchronously with the mains at 50 Hz or 60 Hz.

[0028] In pure battery operation, the loading machine 1 is independently supplied with electrical energy via two high-voltage energy storage units 18 carried on the superstructure 3 of the loading machine 1. Each of the high-voltage energy storage units 18 is typically constructed from energy cells connected in series and / or parallel, in particular lithium-ion battery cells and preferably lithium-ion NMC (nickel, manganese, cobalt) battery cells, and has a total output of 66 kWh (preferably 33 kWh per high-voltage energy storage unit). This capacity is to be understood as the current preferred variant. Other values ​​may arise. The use of lithium titanium oxide cells (LTO cells) is also conceivable, as they offer many technical advantages. Lithium-ion battery cells are characterized, among other things, by high energy densities, thermal stability, and low self-discharge. In the field of automotive technology, high voltage is used for direct voltages above 60 V up to 1,500 V.The output voltage of the high-voltage energy storage units 18 is typically in the range of 400 V to 800 V. In this case, a 580 to 750 V system is used. The high-voltage energy storage units 18 are connected to a DC link 20 of the charging machine 1 via a high-voltage distribution box 19. The high-voltage distribution box 19 is responsible for distributing the electrical energy safely and with low loss from the high-voltage energy storage unit 18 to the inverter 21 and the heat pump 16. The high-voltage distribution box 19 also contains an insulation monitor that monitors the insulation condition, in particular the insulation resistance, in the local three-phase network 13 and in the DC link 20. If the insulation resistance becomes too low, the charging machine 1 is brought into a safe state and shut down.During grid-parallel operation, a so-called PE monitor, which monitors a fault current to earth, assumes the protective function with regard to insulation. This particularly fulfills the increased insulation requirements in the high-voltage range. The DC link 20 feeds an inverter 21, via which the direct current is converted into a three-phase alternating current with a voltage of 400 V. Before this alternating current is fed to the three-phase network 13, a line filter 22 – an electrical circuit – is interposed. By using the line filter 22, any negative influence on a connected network, in particular the customer network or public power grid, can be avoided. The line filter 22 is designed as an LCL filter and smooths the pulsed output signals of the inverter 21.A circuit breaker 28 is arranged behind the mains filter 22 for a switchable connection to the three-phase network 13.

[0029] In the pure battery operation of the charging machine 1, the high-voltage energy storage units 18 feed the three-phase network 13 and thus provide a three-phase 400 V three-phase island network outside the customer network or public power grid.

[0030] An electric heat pump 16 can also be connected directly to the DC link 20. This heat pump works together with coolant pumps 17 for transporting a heat transfer medium and, if necessary, an additional cooler 23. The high-voltage energy storage units 18, the inverter 21, and the line filter 22 are tempered by means of the heat pump 16, the coolant pumps 17, and the cooler 23.

[0031] In addition to the mixed operation described above, the three-phase network 13 described above is fed either from the power grid via the grid connection 12 or as an island network from the high-voltage energy storage units 18.

[0032] The loading machines 1 described here are basically used for handling bulk goods, logs, scrap or recycling material in halls or outdoor areas. This means that the loading machine 1 is used predominantly, i.e. more than 50%, preferably more than 75%, of its daily operating time in a stationary manner in the area of ​​a cable-connected power supply, so that mains operation is possible. It is also conceivable that short travel distances are implemented in stationary mains operation, depending on the length of the cable-connected power supply. In addition to stationary handling operation in mains operation, the loading machine 1 according to the invention can also be used for handling processes in combination with driving operation, for example when unloading transport vehicles, i.e. the loading machine 1 is used in a mobile manner for less than 50%, preferably less than 25%, of its daily operating time.Accordingly, the capacity of the high-voltage energy storage units 18 is designed such that the high-voltage energy storage units 18 of the charging machine 1 are sufficient for approximately 1.5 to 2 hours of operation at typical work and driving performance, as in grid operation. These operating times can be scaled by the number of high-voltage energy storage units 18, so that the machine can be used in pure battery operation for a full working day of up to 8 hours. In this case, the charging machine 1 is charged overnight, for example, and the high-voltage energy storage unit 18 can be used during the charging process for reactive power compensation, provided an external measuring point is available in the power grid, and for peak shaving of the power grid.

[0033] In addition, it is provided that the high-voltage energy storage units 18 can be charged in parallel via the grid connection 12 from the power grid during charging operation in a so-called grid-parallel operation. For this purpose, the grid filter 22 and the inverter 21 are designed to operate bidirectionally in order to provide the high-voltage energy storage units 18 with the required charging current from the power grid. In this grid-parallel operation, the charging machine 1 can, on the one hand, draw its electrical energy from the power grid and, in parallel, charge the high-voltage energy storage units 18 during charging operation, or use the electrical energy present in the high-voltage energy storage units 18 in parallel with the existing connection to the power grid via the common three-phase network 13. For example, the energy from the high-voltage energy storage unit 18 can be used to balance load peaks or can also be fed into the power grid.However, this requires that the three-phase current converted and thus generated from the high-voltage energy storage device 18 is synchronized with the three-phase current from the power grid. For this synchronization, a measuring unit 24 is provided which accesses the three-phase current grid 13 and supplies a controller 25 or a grid controller with the associated measurement data in order to synchronize the three-phase current generated by the inverter 21 with the three-phase current from the power grid, i.e. in particular to adapt the respective phase positions of the three-phase currents to one another. The measuring unit 24 carries out a three-phase voltage measurement of all three phases of the three-phase current upstream and downstream of the circuit breaker 28, which is used to achieve grid synchronization, and a current measurement of all three phases of the three-phase current downstream of the circuit breaker 28, i.e. between the circuit breaker 28 and the soft starter 14, which is used for power regulation.The at least one high-voltage energy storage device 18 or the three-phase current converted therefrom is only connected to the three-phase current of the power grid via the circuit breaker 28 when the three-phase current converted on the charging machine 1 has been synchronized with the three-phase current from the power grid.

[0034] In addition to all other operating modes, the full productivity of the charging machine 1 is also available in grid-parallel operation, also known as grid-synchronous operation. Energy can also be fed into the power grid from the high-voltage energy storage units 18 in feed-in mode. This feed-in mode is used for so-called peak shaving, which refers to the smoothing of load peaks for commercial electricity consumers and contributes to stabilizing the power grid. Peak shaving can be achieved both by feeding power globally into the power grid, in particular the public power grid, for the respective commercial consumer, but also only locally on the charging machine 1 itself, for example by having at least one high-voltage energy storage unit 18 support its operation and thus requiring less power to be drawn from the power grid.Peak shaving of the commercial consumer's power grid can only occur if an additional measuring point is available in the power grid, particularly the customer grid or the public power grid. Furthermore, this grid-synchronous operation also enables reactive power compensation. Commercial consumers usually have high inductive loads and, consequently, high costs for reactive power consumption. For this reason, commercial consumers often install so-called reactive power compensation systems. The grid-synchronous operation of the charging device 1 enables the phase shift between the current and voltage of the fed-in three-phase alternating current to be controlled directly via the inverter 21, thus allowing reactive power compensation.

[0035] The charging machine 1 is therefore fully electric and has no combustion engine.

[0036] The Fig. Figure 3 shows a partial perspective view of an electric loading machine 1 with two high-voltage energy storage units 18. For the sake of simplicity, the boom 4, the boom extension 5, and the load-handling device 6 are not shown. The high-voltage energy storage units 18, the heat pump 16, and the line filter 22 are shown only schematically and are part of an energy storage module 26. The high-voltage energy storage units 18, the heat pump 16, and the line filter 22 are arranged on the superstructure 3 of the loading machine 1, and the energy storage module 26 can be retrofitted in a modular manner to an existing loading machine 1 that operates fully electrically in mains operation.

[0037] The Fig. 4 shows a perspective view of an energy storage module 26 of the charging machine 1 according to Fig. 3. The energy storage module 26 consists of the high-voltage energy storage units 18, the heat pump 16, the high-voltage distribution box 19, the inverter 21 and the mains filter 22, and if necessary also of the coolant pumps 17 (not shown) and the cooler 23 as well as a T-shaped support frame 27. The coolers 23 are arranged on a vertical web 27a of the support frame 27 and the high-voltage energy storage units 18, the heat pump 16 and the mains filter 22 are arranged on a cross web 27b of the support frame 27. When the energy storage module 26 is installed, the cross web 27b of the support frame 27 is preferably supported on the upper carriage 3 and the vertical web 27a is immersed in the upper carriage 3 and supported there.

[0038] In the Fig.Two high-voltage energy storage units 18 are shown in Figures 2 to 4, respectively. Depending on the requirements of the charging machine 1, it is entirely conceivable to provide only one high-voltage energy storage unit 18 or more than two, and in particular up to eight high-voltage energy storage units 18 stacked on top of one another. The main drive of the charging machine 1 has also been described above with only at least one electric motor 15. It is also possible to provide two or more electric motors, for example, one electric motor per axle 8, 9, per wheel 10, or per swivel drive. List of reference symbols 1 loading machine 2 undercarriages 3 superstructures 4 booms 5 boom extension 6 load handling equipment 7 Driver's cab 8 first axis 9 second axis 10 wheels 11 Support element 12 Mains connection 13 Three-phase network 14 soft starter 15 Electric motor 16 heat pump 17 Coolant pump 18 high-voltage energy storage units 19 High-voltage distribution box 20 DC link 21 inverters 22 line filters 23 coolers 24 measuring units 25 Control 26 Energy storage module 27 supporting frames 27a Vertical bridge 27b Crossbar 28 circuit breakers Underground QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] DE 102016106205 A1

[0002] DE 202019105186 U1

[0003]

Claims

[1] Mobile electrically driven loading machine (1), in particular a loading excavator, with at least one electric motor (15) which, in mains operation, draws electrical energy from a mains connection (12), characterized by that at least one high-voltage energy storage device (18) is arranged on the charging machine (1), which in battery operation supplies the at least one electric motor (15) with electrical energy. [2] Loading machine (1) according to claim 1, characterized by that the at least one high-voltage energy storage device (18) feeds a direct current intermediate circuit (20) which is connected to a three-phase network (13) via an inverter (21). [3] Loading machine (1) according to claim 2, characterized by that the at least one electric motor (15) is designed as a three-phase motor. [4] Loading machine (1) according to claim 3, characterized by that the at least one electric motor (15) is designed as an asynchronous motor. [5] Loading machine (1) according to one or more of claims 2 to 4, characterized by that the at least one high-voltage energy storage device (18) feeds the direct current intermediate circuit (20) via a high-voltage distribution box (19). [6] Loading machine (1) according to one or more of claims 2 to 5, characterized by that the mains connection (12) is connected to the three-phase network (13), the inverter (21) is connected to the three-phase network (13) via a mains filter (22) and the inverter (21) is controlled via a controller (25) in such a way that the three-phase current generated by the inverter (21) is synchronized with the three-phase current of the mains connection (12), wherein the controller (25) is connected to the three-phase network (13) via a measuring unit (24). [7] Loading machine (1) according to claim 6, characterized bythat a circuit breaker (28) is arranged between the mains filter (22) and the three-phase network (13) and the voltage of the three-phase current can be measured three-phase before and after the circuit breaker (28) by means of the measuring unit (24). [8] Loading machine (1) according to claim 6 or 7, characterized by that the inverter (21) and the mains filter (22) are each bidirectional and thus electrical energy can be converted and filtered from the direct current intermediate circuit (20) to the three-phase network (13) and from the three-phase network (13) to the direct current intermediate circuit (20). [9] Loading machine (1) according to one or more of claims 6 to 8, characterized by that the at least one high-voltage energy storage device (18), the inverter (21) and the mains filter (22) are tempered via a heat pump (16) and the heat pump (16) is connected to the DC intermediate circuit (20). [10] Loading machine (1) according to one or more of claims 5 to 9, characterized bythat the at least one high-voltage energy storage device (18), the high-voltage distribution box (19), the inverter (21), the mains filter (22) and the heat pump (16) are modularly combined to form an energy storage module (26). [11] Loading machine (1) according to one or more of claims 1 to 10, characterized by that the loading machine (1) essentially consists of an undercarriage (2), an upper carriage (3) arranged on the undercarriage (2) so as to be pivotable about a vertical axis, a boom (4) arranged on the upper carriage (3) so as to be pivotable about a first horizontal axis, and a boom extension (5) arranged at an upper end of the boom (4) and pivotable about a second horizontal axis, said boom extension having a load-carrying means (6). [12] Method for operating a loading machine (1), in particular a loading excavator, according to one of claims 1 to 11, characterized bythat the charging machine (1) is operated either in mains operation or in battery operation and in battery operation three-phase current is generated on the charging machine (1). [13] Method according to claim 12, characterized by that in mains operation the three-phase current of the charging machine (1) is synchronized with the three-phase current of the power grid. [14] Method according to claim 12 or 13, characterized by that the charging machine (1) is predominantly operated in mains operation. [15] Method according to one or more of claims 12 to 14, characterized by that the charging machine (1) is operated in the network operation in parallel with the at least one high-voltage energy storage device (18) in a charging operation. [16] Method according to one or more of claims 12 to 15, characterized bythat the charging machine (1) draws power from the power grid as well as from the high-voltage energy storage device (18) in parallel with respect to the at least one high-voltage energy storage device (18) in the network operation. [17] Method according to one or more of claims 12 to 16, characterized by that in the mains operation of the charging machine (1), electrical energy is supplied to the power grid via the mains connection (12) from the at least one high-voltage energy storage device (18) as required.

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