Device with an energy storage arrangement

Abstract

A device (20) comprises an energy storage arrangement (30), a control unit (23), and an inverter (50), the energy storage arrangement (30) comprising a first terminal (37), a second terminal (38), and a plurality of individual modules (31, 32, 33, 34, 35, 36), each of which individual modules (31, 32, 33, 34, 35, 36) comprise an energy storage device (321) and a circuit arrangement (319), the control unit (23) being configured to enable different configurations of the individual modules (31, 32, 33, 34, 35, 36) between the first terminal (37) and the second terminal (38) by controlling the circuit arrangements (319), the different configurations being at least partially distinguished by the number of modules connected in series between the first terminal (37) and the second terminal (38). They differ in individual modules (31, 32, 33, 34, 35, 36) and in the number of individual modules connected in parallel (31, 32, 33, 34, 35, 36),to provide an output voltage (U_A) resulting from the respective configuration between the first terminal (37) and the second terminal (38), and which control device (23) is designed to set one of the different configurations depending on an input signal (603), which inverter (50) has a DC link (200), and which device (20) is designed to provide a variable voltage (U_Z) at the DC link (200) via the energy storage arrangement (30).

Description

[0001] The invention relates to a device with an energy storage arrangement.

[0002] DE 10 2010 052 934 A1 shows a power converter constructed in the manner of a multilevel converter with individual modules.

[0003] DE 10 2011 108 920 A1 shows different designs of multilevel converters.

[0004] DE 10 2014 100 256 A1 shows a power converter in the form of a modular multilevel converter.

[0005] DE 102021 101 261 A1 shows a modular multilevel converter system.

[0006] It is therefore an object of the invention to provide a new device with an energy storage arrangement.

[0007] This problem is solved by the subject matter of claim 1.

[0008] A device comprises an energy storage arrangement, a control device and an inverter, which energy storage arrangement has a first connection, a second connection and a plurality of individual modules, which individual modules each comprise an energy storage device and a circuit arrangement, which control device is designed to enable different configurations of the individual modules between the first connection and the second connection by controlling the circuit arrangements, which different configurations differ at least partially in the number of individual modules connected in series between the first connection and the second connection and in the number of individual modules connected in parallel to one another, in order to thereby provide an output voltage resulting from the respective configuration between the first connection and the second connection,and which control device is designed to set one of the different configurations depending on an input signal, which inverter has an intermediate circuit, and which device is designed to provide a variable voltage to the intermediate circuit via the energy storage arrangement., The different configurations allow a voltage to be set on the intermediate circuit which, on the one hand, is low when the required speed is low and thus leads to low switching losses, and, on the other hand, the voltage can be increased when the required speed is high.

[0009] According to a preferred embodiment, the energy storage device is an electrochemical energy storage device.

[0010] According to a preferred embodiment, the device has a boost converter, which boost converter has a first boost converter input and a second boost converter input on the input side and a first boost converter output and a second boost converter output on the output side, which boost converter is connected on the input side to the first terminal and to the second terminal and is connected on the output side to the intermediate circuit, and which control device is designed to enable an increase in the voltage at the intermediate circuit compared to the output voltage between the first terminal and the second terminal in a first state by controlling the boost converter. The combination of the configurable energy storage arrangement and the boost converter enables high speeds.

[0011] According to a preferred embodiment, the control device is designed to prevent an increase in the voltage at the intermediate circuit compared to the voltage between the first terminal by controlling the boost converter in a second state. Particularly at low speeds, it is advantageous to deactivate the boost converter due to switching losses.

[0012] According to a preferred embodiment, an inductor and a first semiconductor switch are connected in series between the first boost converter input and the first boost converter output, and have a point in the middle, which point is connected via a second semiconductor switch to both the second boost converter input and the second boost converter output. This circuit enables a boost of the voltage at the boost converter output compared to the boost converter input.

[0013] According to a preferred embodiment, the first semiconductor switch, or the second semiconductor switch, or the first semiconductor switch and the second semiconductor switch are selected from a semiconductor switch group consisting of: - field-effect transistor, in particular metal-oxide-semiconductor field-effect transistor (MOSFET), - Bipolar transistor, in particular insulated gate bipolar transistor (IGBT).

[0014] According to a preferred embodiment, the control device is configured to influence the voltage at the intermediate circuit by controlling the first semiconductor switch and the second semiconductor switch. The voltage at the intermediate circuit influences the power loss of the semiconductor switches of the inverter.

[0015] According to a preferred embodiment, the intermediate circuit has an intermediate circuit capacitor. This smooths the voltage at the intermediate circuit.

[0016] According to a preferred embodiment, the individual modules have a capacitive energy storage device connected in parallel with the electrochemical energy storage device. Capacitive energy storage devices enable the low-impedance supply of electrical currents. This improves the boost converter and the inverter.

[0017] According to a preferred embodiment, the inverter is designed as a two-stage inverter.

[0018] According to a preferred embodiment, the inverter is designed as a voltage source converter.

[0019] According to a preferred embodiment, the inverter has three bridge arms connected to the intermediate circuit. The bridge arms enable control of a three-phase electric machine.

[0020] According to a preferred embodiment, the control device is designed to receive the input signal and to influence the voltage at the intermediate circuit depending on the input signal. This expands the possible applications of the control device.

[0021] According to a preferred embodiment, the control device is designed to enable at least the following operating modes depending on the input signal: A) Deactivated boost converter and setting a first configuration with a first output voltage of the energy storage arrangement; B) Deactivated boost converter and setting a second configuration with a second output voltage of the energy storage arrangement, which second output voltage is greater than the first output voltage; and C) Activated boost converter to increase the voltage at the intermediate circuit compared to the output voltage of the energy storage device.

[0022] These operating modes allow the intermediate circuit voltage to be adjusted to the required speed of the electric machine.

[0023] According to a preferred embodiment, the device comprises an electric machine, which is connected to the inverter. The interaction with an electric machine results in a flexible device.

[0024] According to a preferred embodiment, the device comprises an operating point determination device, which is designed to generate an operating point determination signal characterizing the current operating point of the electric machine. The operating point determination device is designed to supply the operating point determination signal to the control device as an input signal. Using the control device depending on the operating point leads to a significant reduction in the power loss of the inverter.

[0025] Further details and advantageous developments of the invention will become apparent from the exemplary embodiments described below and illustrated in the drawings, which are in no way to be understood as limiting the invention, as well as from the dependent claims. It is understood that the features mentioned above and those to be explained below can be used not only in the respective combinations specified, but also in other combinations or on their own, without departing from the scope of the present invention. It shows: Fig. 1 shows a schematic representation of an individual module of an energy storage arrangement, Fig. 2 shows a schematic representation of an energy storage arrangement with individual modules according to Fig. 1, Fig. 3 shows a schematic representation of a device with the energy storage arrangement of Fig. 2, and Fig. 4 a characteristic curve for a control device.

[0026] In the following, identical or functionally identical parts are provided with the same reference symbols and are usually described only once. The description builds on each figure to avoid unnecessary repetition.

[0027] Fig. Figure 1 shows an individual module 31 of an energy storage arrangement. The individual module 31 comprises an electrochemical energy storage device 321 and a circuit arrangement 319, preferably additionally a capacitive energy storage device 322. The individual module 31 has a terminal 301, a terminal 302, a terminal 303, and a terminal 304.

[0028] Terminal 301 is connected to a line 305 via a semiconductor switch 311 and to a line 306 via a semiconductor switch 312. Terminal 302 is connected to line 305 via a semiconductor switch 313 and to line 306 via a semiconductor switch 314.

[0029] The electrochemical energy storage device 321 is connected to the conductor 305 and to the conductor 306. The capacitive energy storage device 322 is also connected to the line 305 and to the line 306.

[0030] Terminal 303 is connected to line 305 via a semiconductor switch 315 and to line 306 via a semiconductor switch 316. Terminal 304 is connected to line 305 via a semiconductor switch 317 and to line 306 via a semiconductor switch 318.

[0031] By appropriately controlling the circuit arrangement 319, different configurations can be generated when several interconnected individual modules 31 are provided.

[0032] If, for example, the line 305 of a correspondingly constructed individual module arranged to the left of it is connected to the connection 301, a series connection of the two individual modules can be generated by a conductive circuit of the semiconductor switches 312 and 315.

[0033] If, on the other hand, for example, the lines 305, 306 of an individual module arranged to the left of them are connected to the terminals 301, 302, a parallel connection of the adjacent individual modules can be generated by a conductive circuit of the semiconductor switches 311 and 314.

[0034] The circuit arrangement 319 thus enables different configurations between several individual modules 31.

[0035] The present circuit arrangement 319 allows for a great deal of flexibility in interconnecting adjacent individual modules 31. If a smaller number of configurations is sufficient, the circuit arrangement 319 can also be designed more simply. Alternatively, additional semiconductor switches can be provided that enable interconnection with more than two adjacent individual modules.

[0036] Fig. 2 shows an energy storage arrangement 30, which has a first connection 37, a second connection 38 and a control device 23. The energy storage arrangement 30 has, for example, three interconnected individual modules 31, 32, 33. The control device 23 is designed to control the circuit arrangements 319 of Fig. 1 to enable different configurations of the individual modules 31, 32, 33 between the first terminal 37 and the second terminal 38. If, for example, all three individual modules 31, 32, 33 are connected in parallel, the voltage U_A between terminal 37 and terminal 38 approximately corresponds to the voltage of one of the individual modules 31, 32, 33. If, however, all three individual modules 31, 32, 33 are connected in series, the voltage U_A corresponds approximately to three times the voltage of one of the individual modules 31, 32, 33.

[0037] By changing the configuration of the individual modules 31, 32, 33 between the terminals 37, 38, the resulting output voltage U_A can be influenced.

[0038] The control device 23 is connected to a line 602, and an input signal 603 is supplied to the control device 23 via the line 602. The control device 23 is designed to set one of the different configurations depending on the input signal 603.

[0039] The energy storage arrangement 30 preferably has at least five individual modules 31, 32, 33, more preferably at least eight.

[0040] Fig. 3 shows a device 20 which comprises the energy storage arrangement 30, a boost converter 40, an inverter 50 and an electric machine 60.

[0041] The inverter 50 has an intermediate circuit 200, which can also be referred to as a DC voltage intermediate circuit. The device 20 is configured to provide a variable voltage U_Z to the intermediate circuit 200 via the energy storage arrangement 30.

[0042] The boost converter 40 has a first boost converter input 401 and a second boost converter input 402 on the input side. On the output side, the boost converter 40 has a first boost converter output 403 and a second boost converter output 404. The boost converter 40 is connected on the input side to the first terminal 37 and to the second terminal 38 of the energy storage arrangement 30 and connected on the output side to the intermediate circuit 200.

[0043] The boost converter input 401 is connected to a point 42 via an inductance 41, and the point 42 is connected to the boost converter output 403 via a semiconductor switch 43. The boost converter input 402 is connected to the boost converter output 403, and the point 42 is connected to both the boost converter input 402 and the boost converter output 403 via a semiconductor switch 44.

[0044] The semiconductor switch 43, the semiconductor switch 44 or both semiconductor switches 43, 44 are preferably selected from a semiconductor switch group consisting of: - field-effect transistor, in particular metal-oxide-semiconductor field-effect transistor (MOSFET), - Bipolar transistor, in particular insulated gate bipolar transistor (IGBT).

[0045] The control device 23 is configured to influence the voltage U_Z at the intermediate circuit 200 by controlling the first semiconductor switch 43 and the second semiconductor switch 44. The illustrated boost converter can also be referred to as a synchronous converter, and the mutual control of the semiconductor switches 43, 44 to influence the output voltage U_Z is known to those skilled in the art.

[0046] The intermediate circuit 200 has an intermediate circuit capacitor 203, and the intermediate circuit capacitor 203 enables smoothing of the voltage U_Z applied to the intermediate circuit 200 and energy storage.

[0047] The intermediate circuit 200 has a line 201 and a line 202. Line 201 is connected to the boost converter output 403, and line 202 is connected to the boost converter output 404. The intermediate circuit capacitor 203 is connected to line 201 and line 202.

[0048] Line 201 is connected to a point 221 via a semiconductor switch 211, and point 221 is connected to line 202 via a semiconductor switch 212.

[0049] Line 201 is connected to a point 222 via a semiconductor switch 213, and point 222 is connected to line 202 via a semiconductor switch 214.

[0050] Line 201 is connected to a point 223 via a semiconductor switch 215, and point 223 is connected to line 202 via a semiconductor switch 216.

[0051] The semiconductor switches 211 to 216 form three bridge branches 231, 232, 233, and the points 221, 222, 223 are connected to the electric machine 60. This allows a three-phase current to be supplied to the electric machine 60 via the inverter 50.

[0052] The electric machine 60 can be designed, for example, as a three-phase permanent magnet synchronous machine or as an asynchronous machine.

[0053] The inverter 50 shown is designed as a two-stage inverter. A three-stage inverter is also possible. Other voltage source converter designs are also conceivable.

[0054] The device 20 has an operating point determination device 601, which is designed to generate an operating point determination signal 604 characterizing the current operating point of the electric machine 60. The operating point determination device 601 is designed to supply the operating point determination signal 604 to the control device 23 as an input signal 603.

[0055] The operating point of the electric machine 60 can be determined in different ways depending on the application. One possible way of determining this is to determine the operating point from the desired or actual power of the electric machine 60. For this purpose, for example, the current flowing through the electric machine 60 can be determined, or information about the load driven by the electric machine 60 can be used. The speed is also a possible criterion for the operating point, and in particular at high speeds, a comparatively high voltage at the intermediate circuit 200 is necessary. At lower speeds, however, a lower voltage U_Z can be used at the intermediate circuit 200. The control device 23 can provide a suitable voltage U_Z at the intermediate circuit 200 depending on the input signal 603. At a low load on the electric machine 60, for example,By connecting several individual modules 31, 32, 36 in parallel, the output voltage U_A of the energy storage arrangement 30 can be reduced, and the boost converter 40 can be deactivated by switching the semiconductor switch 43 on and switching the semiconductor switch 44 off. This provides a comparatively low voltage U_Z at the intermediate circuit 200. Since the losses at the semiconductor switches 211 to 216 depend on the intermediate circuit voltage U_Z, a reduction in the intermediate circuit voltage U_Z leads to a reduction in the losses in the inverter 50.

[0056] As the speed of the electric machine 60 increases, the voltage U_Z can be increased by reconfiguring the energy storage arrangement 30 and increasing the output voltage U_A. Particularly at very high speeds of the electric machine 60, the voltage U_Z at the intermediate circuit 200 can be further increased by activating the boost converter 40, and high speeds of the electric machine 60 are possible. For activation, the two semiconductor switches 43, 44 are operated in push-pull mode.

[0057] The device 20 can therefore operate at the different operating points of the electric machine 60 at low power with little power loss, but it can enable a high maximum power at operating points with high load or speed.

[0058] When the electric machine 60 is used, the boost converter 40 can be used as a buck converter during energy transfer from the electric machine 60 to the energy storage arrangement 30 in order to enable recuperation even at high speeds.

[0059] Fig. 4 shows an example of a characteristic curve 80 for the control device 23.

[0060] The speed n is indicated on the abscissa as a parameter for the operating point of the electric machine 60. Alternatively, a combination of the speed n and a winding current I could be used.

[0061] The ordinate shows the intermediate circuit voltage U_Z, and the intermediate circuit voltage U_Z is given as a function of the speed n.

[0062] Up to a low speed n1, a first configuration of the energy storage arrangement 30 is set with a low output voltage U_A, and the boost converter 40 is deactivated, so that the intermediate circuit voltage U_Z corresponds to the output voltage U_A. The switching losses of power semiconductor switches depend on the commutation voltage. Therefore, reducing the intermediate circuit voltage leads to a reduction in the switching losses. Furthermore, charge equalization can be performed between individual modules connected in parallel.

[0063] Between speeds n1 and n2, a second configuration of the energy storage arrangement 30 is set with a higher output voltage U_A and thus also a higher intermediate circuit voltage U_Z. The electric motor 60 can thus be operated with more power.

[0064] Between the speeds n2 and n3, the output voltage U_A and the intermediate circuit voltage U_Z are further increased by setting a third configuration of the energy storage arrangement 30.

[0065] Between the speeds n3 and n4, the output voltage U_A and the intermediate circuit voltage U_Z are further increased by setting a fourth configuration of the energy storage arrangement 30.

[0066] Above speed n4, the intermediate circuit voltage U_Z is further increased by activating the boost converter 40, thereby increasing the intermediate circuit voltage U_Z relative to the output voltage U_A of the energy storage device 30. The electric machine can therefore achieve high speed and power.

[0067] Generally speaking, the control device 23 is designed to enable at least the following operating modes depending on the input signal 603: A) Deactivated boost converter 40 and setting a first configuration with a first output voltage U_A of the energy storage arrangement 30 (e.g. between the speeds 0 and n1); B) Deactivated boost converter 40 and setting a second configuration with a second output voltage U_A of the energy storage arrangement 30, which second output voltage U_A is greater than the first output voltage (e.g. between the speeds n2 and n3); and C) Activated boost converter to increase the voltage U_Z at the intermediate circuit 200 compared to the output voltage U_A of the energy storage device 30 (e.g. from the speed n4).

[0068] Naturally, various variations and modifications are possible within the scope of the present invention. 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 10 2010 052 934 A1

[0002] DE 10 2011 108 920 A1

[0003] DE 10 2014 100 256 A1

[0004] DE 102021 101 261 A1

[0005]

Claims

[1] Device (20) comprising an energy storage arrangement (30), a control device (23) and an inverter (50), which energy storage arrangement (30) comprises a first connection (37), a second connection (38) and a plurality of individual modules (31, 32, 33, 34, 35, 36), which individual modules (31, 32, 33, 34, 35, 36) each comprise an energy storage device (321) and a circuit arrangement (319), which control device (23) is designed to enable different configurations of the individual modules (31, 32, 33, 34, 35, 36) between the first connection (37) and the second connection (38) by controlling the circuit arrangements (319), which different configurations differ at least partly in the number of between the first connection (37) and the second connection (38) in series-connected individual modules (31, 32, 33, 34, 35, 36) and in the number of individual modules (31, 32, 33, 34, 35, 36) connected in parallel,in order to thereby provide an output voltage (U_A) resulting from the respective configuration between the first terminal (37) and the second terminal (38), and which control device (23) is designed to set one of the different configurations as a function of an input signal (603), which inverter (50) has an intermediate circuit (200), and which device (20) is designed to provide a variable voltage (U_Z) at the intermediate circuit (200) via the energy storage arrangement (30). [2] Device (20) according to claim 1, which has a boost converter (40), which boost converter (40) has on the input side a first boost converter input (401) and a second boost converter input (402) and on the output side a first boost converter output (403) and a second boost converter output (404), which boost converter (40) is connected on the input side to the first terminal (37) and to the second terminal (38) and is connected on the output side to the intermediate circuit (200), and which control device (23) is designed to enable, in a first state, by controlling the boost converter (40), an increase in the voltage (U_Z) at the intermediate circuit (200) compared to the output voltage (U_A) between the first terminal (37) and the second terminal (38). [3] Device (20) according to claim 2, wherein the control device (23) is designed to prevent, in a second state, an increase in the voltage (U_Z) at the intermediate circuit (200) compared to the voltage between the first terminal (37) by the boost converter (40) by controlling the boost converter (40). [4] Device (20) according to claim 2 or 3, wherein an inductance (41) and a first semiconductor switch (43) are connected in series between the first boost converter input (401) and the first boost converter output (403) and have a point (42) in the middle, which point (42) is connected via a second semiconductor switch (44) both to the second boost converter input (402) and to the second boost converter output (404). [5] Device (20) according to claim 4, wherein the first semiconductor switch (43), or the second semiconductor switch (44), or the first semiconductor switch (43) and the second semiconductor switch (44) are selected from a semiconductor switch group consisting of: - field-effect transistor, in particular metal-oxide-semiconductor field-effect transistor (MOSFET), - Bipolar transistor, in particular insulated gate bipolar transistor (IGBT). [6] Device (20) according to claim 4 or 5, wherein the control device (23) is configured to influence the voltage (U_Z) at the intermediate circuit (200) by controlling the first semiconductor switch (43) and the second semiconductor switch (44). [7] Device (20) according to one of the preceding claims, in which the intermediate circuit (200) has an intermediate circuit capacitor (203). [8] Device (20) according to one of the preceding claims, in which the individual modules (31, 32, 33, 34, 35, 36) have a capacitive energy storage device (322) which is connected in parallel with the electrochemical energy storage device (321). [9] Device (20) according to one of the preceding claims, in which the inverter (50) is designed as a voltage intermediate circuit converter. [10] Device (20) according to one of the preceding claims, in which the inverter (50) has three bridge branches (231, 232, 233) connected to the intermediate circuit (200). [11] Device (20) according to one of the preceding claims, in which the control device (23) is designed to receive the input signal (603) and to influence the voltage (U_Z) at the intermediate circuit (200) as a function of the input signal (603). [12] Device (20) according to claim 11, wherein the control device (23) is designed to enable at least the following operating modes depending on the input signal (603): A) Deactivated boost converter (40) and setting a first configuration with a first output voltage (U_A) of the energy storage arrangement (30); B) Deactivated boost converter (40) and setting a second configuration with a second output voltage (U_A) of the energy storage arrangement (30), which second output voltage (U_A) is greater than the first output voltage; and C) Activated boost converter for increasing the voltage (U_Z) at the intermediate circuit (200) compared to the output voltage (U_A) of the energy storage arrangement (30). [13] Device (20) according to one of the preceding claims, which comprises an electric machine (60), which electric machine (60) is connected to the inverter (50). [14] Device (20) according to claim 12, which has an operating point determination device (601), which operating point determination device (601) is designed to generate an operating point determination signal (604) characterizing the current operating point of the electric machine (60), and which operating point determination device (601) is designed to supply the operating point determination signal (604) to the control device (23) as an input signal (603).

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