Energy Supply Device and Construction Machine

Abstract

An energy supply device for supplying electric loads with electric energy, includes a DC link; a first mains connection to which a first AC voltage grid can be connected as intended; a first rectifier which is designed to rectify an AC voltage corresponding to an AC voltage across the first mains connection or based thereon and to feed the rectified voltage into the DC link; a second mains connection to which a second AC voltage grid can be connected as intended; a second rectifier which is designed to rectify an AC voltage corresponding to an AC voltage across the second mains connection or based thereon; a controllable DC-to-DC converter to a first side of which a voltage rectified by means of the second rectifier is applied, and a second side of which is connected to the DC link; a first current converter which is fed from the DC link and is designed to supply a first electric load with electric energy; a power measuring apparatus which is designed to measure electric power consumed at the first mains connection; and a control apparatus which has a data link to the power measuring apparatus and which is designed to control the DC-DC converter according to the electric power consumed at the first mains connection.

Claims

1.-10. (canceled)

11. An energy supply device for supplying electrical loads with electrical energy, comprising: an intermediate circuit; a first network connection to which a first AC voltage network is able to be connected as intended; a first rectifier that is designed to rectify an AC voltage, which corresponds to an AC voltage present at the first network connection, or is based thereon, and to feed the rectified voltage to the intermediate circuit; a second network connection to which a second AC voltage network is able to be connected as intended; a second rectifier that is designed to rectify an AC voltage, which corresponds to an AC voltage present at the second network connection, or is based thereon; a controllable DC/DC converter, to a first side of which the voltage rectified by the second rectifier is applied, and a second side of which is connected to the intermediate circuit; a first converter that is fed from the intermediate circuit and that is designed to supply a first electrical load with electrical energy; a power measuring apparatus that is designed to measure an electric power drawn at the first network connection; and a control apparatus that has a data connection to the power measuring apparatus and that is designed to actuate the DC/DC converter depending on the electric power drawn at the first network connection.

12. The energy supply device according to claim 11, wherein when the electric power drawn at the first network connection exceeds a threshold value, the control apparatus actuates the DC/DC converter such that electric power is transmitted from the second network connection in a direction of the intermediate circuit.

13. The energy supply device according to claim 11, wherein the control apparatus actuates the DC/DC converter such that a maximum electric power able to be output by the energy supply device corresponds to a sum of the maximum available electric power at the first network connection and the maximum available electric power at the second network connection.

14. The energy supply device according to claim 11, further comprising: a second converter that is fed from the intermediate circuit and that is designed to supply a second electrical load with electrical energy.

15. The energy supply device according to claim 11, further comprising: a galvanically isolating transformer, wherein a first winding of the galvanically isolating transformer is connected to the second network connection, and a second winding of the galvanically isolating transformer is connected to the second rectifier.

16. The energy supply device according to claim 11, wherein the first network connection is a 32 A network connection.

17. The energy supply device according to claim 16, wherein the second network connection is a 16 A network connection.

18. The energy supply device according to claim 11, wherein the second network connection is a 16 A network connection.

19. A construction machine, comprising: an energy supply device according to claim 11; and an electric drive that is supplied with electrical energy by way of the first converter of the energy supply device.

20. The construction machine according to claim 19, wherein the construction machine is a thick matter discharge device for discharging thick matter, and the thick matter discharge device comprises the electrical drive in the form of an electrical mixer drive for mixing the thick matter, which is supplied with electrical energy by way of the first converter of the energy supply device.

21. The construction machine according to claim 20, wherein the thick matter discharge device further comprises: an electrical compressor for generating compressed air, which is supplied with electrical energy by way of a second converter of the energy supply device.

Description

BRIEF DESCRIPTION OF THE DRAWING

[0023] FIG. 1 schematically shows a block diagram of a construction machine having an energy supply device, according to an embodiment of the invention, for supplying electrical loads of the construction machine with electrical energy.

DETAILED DESCRIPTION OF THE DRAWING

[0024] FIG. 1 schematically shows a block diagram of a construction machine in the form of a thick matter discharge device 1000 for discharging thick matter, having an energy supply device 100 for supplying electrical loads, in the form of a compressor 1 and a mixer drive 2, of the thick matter discharge device 1000 with electrical energy/power.

[0025] The energy supply device 100 has an intermediate circuit 3, at which an intermediate circuit DC voltage of, for example, 550 V DC is present in the case of a network voltage connection of 400 V 3 AC.

[0026] The energy supply device 100 also has a first network connection 4 to which a first AC voltage network 5 is able to be connected as intended, for example a construction power network with a current-carrying capacity of 32 A.

[0027] The energy supply device 100 also has an optional conventional network filter 16 and an optional downstream smoothing inductor 17 that has a first rectifier 6 connected downstream thereof. The first rectifier 6 is designed to rectify an AC voltage present at the first network connection 4 and to feed the rectified voltage to the intermediate circuit 3.

[0028] The energy supply device 100 also has a second network connection 7 to which a second AC voltage network 8 is able to be connected as intended, for example a construction power network with a current-carrying capacity of 16 A.

[0029] The energy supply device 100 also has an optional conventional network filter 18 and a galvanically isolating transformer 15, wherein a first winding, or primary winding 15a, of the galvanically isolating transformer 15 is connected to the second network connection 7 via the network filter 18, and a second winding, or secondary winding 15b, of the galvanically isolating transformer 15 is connected to a second rectifier 9. The second rectifier 9 is designed to rectify an AC voltage that is present at the second winding 15b of the galvanically isolating transformer 15 and is based on an AC voltage present at the second network connection 7.

[0030] The energy supply device 100 also has a controllable DC/DC converter 10, to a first side of which the voltage rectified by means of the second rectifier 9 is applied, and a second side of which is connected to the intermediate circuit 3 with the interposition of an optional smoothing inductor 19.

[0031] The energy supply device 100 also has a first converter in the form of an inverter 11 that is fed from the intermediate circuit 3 and that is designed to supply the mixer drive 2 with electrical energy.

[0032] The energy supply device 100 also has a second converter in the form of an inverter 14 that is fed from the intermediate circuit 3 and is designed to supply the compressor 1 with electrical energy.

[0033] The energy supply device 100 also has a power measuring apparatus 12 that is designed to measure an electric power drawn at the first network connection 4.

[0034] The energy supply device 100 also has a control apparatus 13 that has a data connection to the power measuring apparatus 12 and that is designed to actuate the DC/DC converter 10 depending on the electric power drawn at the first network connection 4. If the electric power drawn at the first network connection 4 exceeds a threshold value, the control apparatus 13 actuates the DC/DC converter 10 in such a way that electric power is transmitted from the second network connection 7 in the direction of the intermediate circuit 3. This makes it possible for a maximum electric power able to be output by the energy supply device 100 to correspond to a sum of the maximum available electric power at the first network connection 4 and the maximum available electric power at the second network connection 7.

[0035] Available network connection sockets for supplying construction machines with electric power often cause problems with respect to the available electric connection power. By way of example, a 63 A connection is needed to provide an electric power of 30 kW. Since this connection is not always available and usual construction power distributors are predominantly also only protected at 63 A, only 32 A and 16 A connections usually remain for electric drives of construction machines. The maximum power of the electrical load is currently limited by the maximum connection power of a connection.

[0036] FIG. 1 shows an example of a possible circuit with a 32 A connection 4 and a 16 A connection 7.

[0037] At the 16 A connection 7, potential isolation takes place with an increase in voltage. The DC/DC converter 10 shifts electric power to the intermediate circuit 3 in a current-controlled manner. The potential reference arises via the coupling in the intermediate circuit 3. The central controller 13 checks when additional power is required from the 16 A connection 7 by way of the measuring apparatus 12 at the 32 A connection 4. If all the loads 1, 2 are connected to the 32 A path, the construction machine 1000 can optionally also be operated only at the 32 A connection 4.

[0038] According to the invention, a plurality of energy paths or a plurality of connections 4 and 7 are combined in such a way that the usable power increases to the sum of the connection powers. In other words, electrical energy/power is contributed by other connections to the main connection 4 as required, without there being a fixed association between loads 1, 2 and connections 4 and 7. The power of the other connection 7 is supplied to the intermediate circuit 3 and the power yield is maximized overall by measuring the power draw at the main connection 4.

[0039] It goes without saying that other second network connections 7 can also be present. The other connection paths then correspond to the path at the second network connection 7, comprising the components: optional network filter 18, galvanically isolating transformer 15, rectifier 9 and DC/DC converter 10, which (also) feeds the intermediate circuit 3.

[0040] It goes without saying that more than two converters 11 and 14 fed from the intermediate circuit 3 can also be present for supplying other electrical loads with power.

[0041] A maximum power yield of the electrical connection power, for example of a construction machine having two (or more) network connections, is possible by means of the invention. Owing to the galvanically isolating transformer 15, the connections 4 and 7 do not have any influence on one another.