Method for black starting a power supply installation, bidirectional inverter, and power supply installation with a bidirectional inverter

Abstract

A method for black starting a power supply device is disclosed, wherein the power supply device includes at least one bidirectional inverter having an AC-side connection for a grid and a battery connected to the DC side of the bidirectional inverter. The method includes operating an activation device of the power supply device so that the activation device applies a voltage to a control line of the battery to place the battery into an operating state, wherein the voltage provided by the activation device is provided by an auxiliary battery. The method also includes putting the bidirectional inverter into an operating state after the voltage provided by the auxiliary battery is applied to the control line.

Claims

1. A method for black starting a power supply device, wherein the power supply device comprises a bidirectional inverter having an AC-side connection for a grid and a battery connected to the DC side of the bidirectional inverter, the method comprising: operating an activation device of the power supply device so that the activation device applies a voltage to a control line of the battery to place the battery into an operating state, wherein the voltage provided by the activation device is provided by an auxiliary battery, and putting the bidirectional inverter into an operating state after the voltage provided by the auxiliary battery is applied to the control line.

2. The method as claimed in claim 1, further comprising: using the battery that has been put into an operating state by the activation device to make a DC supply voltage available to the bidirectional inverter, wherein the DC supply voltage puts the bidirectional inverter into an operating state.

3. The method as claimed in claim 1, wherein the power supply device has a separate backup device or a backup device that the bidirectional inverter comprises, and wherein in a first case the separate backup device is also supplied with a supply voltage and put into an operating state by the bidirectional inverter.

4. The method as claimed in claim 1, wherein the bidirectional inverter, in the operating state, takes over the provision of the voltage, initially provided by the activation device, on a control line of the battery, and the activation device is put into an initial state for the battery.

5. The method as claimed in claim 1, further comprising initiating a handshake protocol between the battery and the bidirectional inverter for the purpose of setting up a communication between the two.

6. The method as claimed in claim 5, wherein an absence of a successful communication setup between the bidirectional inverter and the battery results in the provision of a DC supply voltage for the bidirectional inverter by the battery being stopped.

7. The method as claimed in claim 1, wherein the power supply device comprises further batteries connected to the bidirectional inverter, wherein the further batteries are each provided with a voltage on a control line, which voltages put the further batteries into an operating state, respectively, wherein the voltage is provided by the activation device and/or the bidirectional inverter, and wherein the further batteries, in the operating state, each make a DC supply voltage available to the bidirectional inverter and a handshake protocol is started between the further battery and the bidirectional inverter in each case for the purpose of setting up a communication between the two.

8. The method as claimed in claim 1, wherein the power supply device comprises further bidirectional inverters, each having at least one battery connected to the further bidirectional inverter, respectively, and in each case at least one connected battery of the further bidirectional inverters is provided with a voltage on a control line that puts the connected battery into an operating state, wherein the voltage is provided by the activation device or the bidirectional inverter or a separate backup device put into an operating state by the bidirectional inverter.

9. A bidirectional inverter, comprising: a control device and interfaces for connecting a battery on a DC side thereof and for connecting a grid on an AC side thereof, wherein at least one supply interface is arranged for connecting two battery poles of the battery to the bidirectional inverter, an interface for a control line of the battery, and an activation device having an auxiliary battery, wherein the activation device is configured so as, when the activation device is operated in the event of a black start, to provide on the interface for the control line a voltage, provided by the auxiliary battery, that is suitable for starting up the battery.

10. The bidirectional inverter as claimed in claim 9, wherein the bidirectional inverter is configured to be put into an operating state by the battery in the event of a black start by applying to the supply interface a DC supply voltage, provided by the battery, that is suitable for putting the bidirectional inverter into an operating state.

11. The bidirectional inverter as claimed in claim 9, wherein the control device is configured so as, in the event of a black start, to take over the provision of a voltage to maintain an operating state of the battery after the bidirectional inverter is started up.

12. The bidirectional inverter as claimed in claim 11, wherein the control device is configured to put the activation device into an initial state for the battery after said provision is taken over.

13. The bidirectional inverter as claimed in claim 9, wherein the bidirectional inverter comprises interfaces for connecting multiple batteries, wherein the activation device is configured such that the activation device, in the event of a black start, provides on the interfaces for the control lines voltages, provided by the auxiliary battery, that are suitable for starting up the batteries, and wherein the control device is configured so as, in the event of a black start, to take over the provision of the voltages to maintain the operating state of the batteries after the bidirectional inverter is started up and to put the activation device into an initial state for the batteries.

14. The bidirectional inverter as claimed in claim 9, wherein the DC side of the bidirectional inverter additionally has an input configured to connect to a solar installation.

15. The bidirectional inverter as claimed in claim 9, wherein the bidirectional inverter comprises an internal backup device or a connection for a separate backup device, wherein the connection comprises at least one supply interface, wherein, in a second case, the control device is configured so as, in the event of a black start, to provide a supply voltage on the supply interface after the bidirectional inverter is started up and to put the separate backup device into an operating state.

16. The bidirectional inverter as claimed in claim 9, wherein the bidirectional inverter comprises at least one field bus interface for communication with the battery.

17. A backup device having a control device and an activation device having an auxiliary battery, comprising: at least one interface for a supply voltage of the backup device and at least one interface for a control line of a battery, wherein the activation device is configured so as, when the activation device is operated in the event of a black start, to provide on the at least one interface for the control line of the battery a voltage, provided by the auxiliary battery, that is suitable for starting up the battery.

18. The backup device as claimed in claim 17, wherein the backup device is configured so that, from a shut-down state or standby mode, when: the interface for the supply voltage has a supply voltage applied to it, or the interface for the supply voltage has a supply voltage applied to it and additionally an interface for a control line of the backup device has an enabling signal applied to it, the backup device changes to an operating state.

19. The backup device as claimed in claim 17, wherein: at least one further interface for a supply voltage of the backup device, or at least one further interface for a supply voltage of the backup device and at least one further interface for a control line of the backup device is comprised.

20. A power supply device, comprising: at least one bidirectional inverter having an AC-side interface for connecting a grid, at least one battery connected to the DC side of the bidirectional inverter, and at least one activation device having an auxiliary battery, wherein the bidirectional inverter comprises interfaces for connecting the battery on the DC side, wherein at least one supply interface is arranged for connecting two battery poles of the battery to the bidirectional inverter, and the activation device is configured, when the activation device is operated in the event of a black start, to provide on an interface for a control line of at least one battery a voltage, provided by the auxiliary battery, that is suitable for setting up the battery.

21. The power supply device as claimed in claim 20, further comprising a separate backup device.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 schematically shows a power supply device,

(2) FIG. 2 schematically shows a power supply device according to an exemplary embodiment of the disclosure in a shut-down state,

(3) FIG. 3 schematically shows the power supply device of FIG. 2 at a first point in time during black starting according to an exemplary embodiment of the method according to the disclosure,

(4) FIG. 4 schematically shows the power supply device of FIG. 2 at a second point in time during black starting,

(5) FIG. 5 schematically shows the power supply device of FIG. 2 at a third point in time during black starting,

(6) FIG. 6 schematically shows the power supply device of FIG. 2 at a fourth point in time during black starting,

(7) FIG. 7 schematically shows the power supply device of FIG. 2 at a fifth point in time during black starting,

(8) FIG. 8 schematically shows the power supply device of FIG. 2 at a sixth point in time after completion of black starting according to the exemplary embodiment of the method according to the disclosure, and

(9) FIG. 9 schematically shows the power supply device of FIG. 2 at a seventh point in time during subsequent normal operation according to an exemplary embodiment.

DETAILED DESCRIPTION

(10) The disclosure relates to a method for black starting a power supply device comprising a bidirectional inverter and a battery connected to the DC side of the inverter.

(11) The disclosure also relates to a bidirectional inverter suitable for use with the method. The bidirectional inverter comprises a control device and interfaces for connecting a battery on the DC side and for connecting of a grid on the AC side. The interfaces for connecting the battery on the DC side comprise at least one supply interface for connecting two battery poles to the inverter.

(12) The disclosure also relates to a backup device for a power supply device that is suitable for use with the method.

(13) The disclosure also relates to a power supply device suitable for use with the method. The power supply device comprises at least one bidirectional inverter having an AC-side interface for connection of a grid, and at least one battery connected to the DC side of the inverter.

(14) FIG. 1 schematically shows a conventional power supply device 1. The power supply device 1 is part of a power station 2 having a solar installation 3. The power supply device 1 comprises a bidirectional inverter 4 and a battery 5, wherein the AC side of the bidirectional inverter 4 has a grid 6 connected to it and the DC side of the bidirectional inverter has the battery 5 and the solar installation 3 connected to it. The parts of the bidirectional inverter that are depicted in the figure are an inverter bridge 7, two input DC choppers 8 and 9 and also a DC link circuit 10 and a control device 11. The DC link circuit 10 comprises a DC link capacitor (not depicted). The grid 6 connected to the AC side of the bidirectional inverter 4 comprises a local grid 12 and a public grid 14. The local grid 12 can be reversibly disconnected from the public grid 14 by means of an isolating switch 15. The local grid 12 has a load 16 connected to it. The solar installation 3 is connected to an input 17 of the bidirectional inverter 4 on the DC side.

(15) The bidirectional inverter 4 can transport electrical energy in both directions. The battery 5 can therefore be charged with electrical energy from the grid 6 or by the solar installation 3 via the bidirectional inverter 4. Electrical energy can be supplied to the grid 6 by the solar installation 3 and the battery 5 via the bidirectional inverter 4. The bidirectional inverter 4 can comprise further supplementary functions, such as for example the provision of power to support the public grid 14 or optimization of an operating point of the solar installation 3 (MPP tracking).

(16) FIG. 2 schematically shows a power supply device 18 according to a first exemplary embodiment of the disclosure in a shut-down state.

(17) The power supply device 18 comprises a bidirectional inverter 20, a battery 22 connected to the DC side of the inverter and a separate backup device 24. For the purpose of connecting the battery 22, the bidirectional inverter 20 comprises interfaces with an interface 26 for a control line 27 of the battery and a supply interface 28 for connecting the two battery poles of the battery. Additionally, the bidirectional inverter 20 comprises a field bus interface 30 for a field bus connection 32 for communication with the battery. A further interface 33 is used to provide a supply of voltage for a battery management system of the battery 22 via the connection 34. In the direction of the separate backup device 24, the bidirectional inverter 20 comprises interfaces with an interface 35 for a control line 37, which actuates an interface 42, and a supply interface 38 for a supply voltage that is made available to the backup device on the interface 44. Additionally, another field bus connection 40 is depicted between the bidirectional inverter 20 and the separate backup device 24, for communication between the two devices.

(18) An AC-side interface 25 of the bidirectional inverter 20 is connected to a grid 6. The grid 6 comprises a public grid 14 and a local grid 12, the two being able to be reversibly disconnected from one another by means of an isolating device 19.

(19) The bidirectional inverter 20 comprises a control device 50 and an activation device 51. The activation device 51 has an auxiliary battery 52 and is partially integrated in the control device 50.

(20) A method for black starting the power supply device 18 according to an exemplary embodiment of the disclosure will be depicted and explained in more detail below with reference to FIGS. 3 to 8, an explanation of the function of the power supply device 18 depicted here also being provided in association therewith.

(21) FIG. 3 schematically shows the power supply device 18 of FIG. 2 at a first point in time during black starting according to an exemplary embodiment of the method according to the disclosure. Only the reference numerals according to FIG. 2 that are relevant to the description of FIG. 3 are depicted.

(22) At the first point in time, the activation device 51 has been operated and provides an enabling signal in the form of a voltage on the interface 26. The voltage is provided by the auxiliary battery 52 and applies an enabling signal to the control line 27. The application of the enabling signal to the control line 27 is identified in the figure by an emboldened line fashioning for the control line 27. At this point in time, the bidirectional inverter 20 is not in operating state as is intended to be understood within the context of this disclosure.

(23) FIG. 4 schematically shows the power supply device 18 of FIG. 2 at a second point in time during black starting according to the exemplary embodiment of the method according to the disclosure. Similarly, only the reference numerals according to FIG. 2 that are relevant to the description of FIG. 4 are depicted.

(24) As compared with FIG. 3, the battery 22 is now in an operating state at the second point in time, said operating state being identified in FIG. 4 by the lighter fashioning of the device. The battery 22 has been put into an operating state on account of the voltage applied to the control line 27. The control line 27 can also be referred to as Enable line. The voltage provided by the activation device 51 corresponds to a voltage value that is interpreted by the battery 22 as an enabling signal and puts said battery into an operating state. At the second point in time, the activation device 51 continues to make the enabling signal available.

(25) FIG. 5 schematically shows the power supply device of FIG. 2 at a third point in time during black starting according to the exemplary embodiment of the method according to the disclosure.

(26) The battery 22, which is in an operating state, makes a DC supply voltage available to the bidirectional inverter 20 on the supply interface 28 at a third point in time, said DC supply voltage being suitable for putting the bidirectional inverter 20 into an operating state. The activation device 51 still applies the enabling signal to the control line 27 at this point in time.

(27) FIG. 6 schematically shows the power supply device 18 at a fourth point in time during black starting according to the exemplary embodiment of the method according to the disclosure.

(28) The bidirectional inverter 20 has been put into an operating state by the DC supply voltage on the supply interface 28 and continues to be supplied with a DC supply voltage by the battery 22. The activation device 51 continues to use the auxiliary battery 52 to make the enabling signal available for the battery on the control line 27.

(29) FIG. 7 schematically shows the power supply device 18 at a fifth point in time during black starting according to the exemplary embodiment of the method according to the disclosure.

(30) The control device 50 of the bidirectional inverter 20 has taken over the provision of the voltage, initially provided by the auxiliary battery 52, on the interface 26 to maintain the operating state of the battery 22 and has put the activation device 51 into an initial state. The energy for this is obtained by the control device 50 from the DC supply voltage provided by the battery 22.

(31) Using the field bus connection 32, the battery 22 and the bidirectional inverter 20 now start a handshake protocol to set up a communication between the two.

(32) Moreover, the bidirectional inverter 20 uses the supply interface 38 to supply the separate backup device 24 with a supply voltage and makes an enabling signal available on the interface 35 for the control line 37 of the separate backup device. To this end, the control device 50 is configured as appropriate. The energy for this is obtained by the bidirectional inverter 20 from the applied DC supply voltage from the battery 22 via the supply interface 28.

(33) The enabling signal on the control line 37 and/or the supply voltage for the separate backup device 24 are suitable for putting the separate backup device into an operating state.

(34) FIG. 8 schematically shows the power supply device 18 at a sixth point in time after completion of black starting according to the exemplary embodiment of the method according to the disclosure.

(35) The separate backup device 24, which has been put into an operating state by the enabling signal and/or the supply voltage, and the bidirectional inverter 20 have set up a communication between the two devices after successful completion of a handshake protocol via the field bus connection 40. The battery 22 and the bidirectional inverter 20 have also set up a communication via the field bus connection 32. Additionally, the bidirectional inverter 20 makes a supply voltage of the battery 22 available for a battery management system (not depicted) on the interface 33 via the connection 34. In this state, the power supply device can begin normal operation.

(36) FIG. 9 shows the power supply device 18 of FIG. 2 at a seventh point in time during subsequent normal operation according to an exemplary embodiment.

(37) The backup device 24 comprises a control module 46 having a microcontroller 48 and is connected (not depicted) to sensors (not depicted) and the isolating device 19. The backup device 24 is designed so as, in interaction with the bidirectional inverter 20, to allow emergency operation of the local grid 12 in the event of failure of the public grid 14. According to the exemplary embodiment depicted, the backup device 24 has to this end detected failure of the public grid 14 and disconnected the local grid 12 from the public grid 14 by actuating the isolating device 19 and, in interaction with the bidirectional inverter 20, set up an island mode of the local grid 12. In this instance, the bidirectional inverter 20 draws electrical energy from the battery 22, which electrical energy it then makes available to the connected loads (not depicted) of the local grid 12.