Structure and control method for a modular brake modulator with at least two brake modulator branches

Abstract

This invention relates to a method for operating a modular brake regulator (1), wherein the modular brake regulator (1) has at least two brake regulator branches (15), each of which has at least one submodule (2) and a brake resistor (3); wherein the brake regulator branches (15) are arranged in a parallel circuit, and wherein at least two of the brake regulator branches (15) generate an alternating component (u) by means of the corresponding at least one submodule (2). BR,aDC voltage (u) BR ), wherein the alternating component (u) of each brake regulator branch (15) BR,aDC The phase offset between them, where n corresponds to the number of the braking regulator branches (15) that generate the voltage; where all alternating components (u BR,aDC The amplitudes are the same, and it is designed to convert the electrical energy absorbed by the modular brake regulator (1) over time into heat in the brake resistor (3). Furthermore, the invention relates to a control device (10) configured to perform such a method. The invention also relates to a modular brake regulator (1) having such a control device, and a modular drive unit (20) having a modular multilevel converter (21) and such a modular brake regulator (1).

Description

Technical Field

[0001] This invention relates to a method of operating a modular brake regulator having at least one submodule and a braking resistor. Furthermore, this invention relates to a control device and a modular brake regulator, wherein the modular brake regulator includes at least one submodule and a braking resistor. The invention also relates to a modular drive unit having a modular multilevel converter and such a modular brake regulator, wherein the modular brake regulator is electrically connected to the DC voltage side of the modular multilevel converter. Background Technology

[0002] A modular multilevel converter has been disclosed in DE 10 103 031 A1. This converter, also known as M2C or MMC, features a converter topology particularly suitable for medium and high voltage applications due to its submodule structure. The basic structure of this multiphase converter includes two converter arms per phase, each with a series circuit of a submodule. The two converter arms are connected to each other at the phase terminals. Further sides of the converter arms are connected to the DC voltage side. The AC voltage side of the modular multilevel converter is formed by one or more phase terminals. In its basic structure, energy can be transferred bidirectionally between the DC and AC voltage sides via this converter, or intermediate energy storage can be performed to some extent.

[0003] To achieve additional targeted energy dissipation, it is appropriate to install a brake regulator. A modular brake regulator is disclosed in WO 2007 / 023061 A2. Modular brake regulators are typically connected, for example, between the DC+ and DC- terminals to the DC voltage side of a modular multilevel converter.

[0004] The resistor in a brake regulator device is often referred to as a brake resistor because it is suitable for converting the electrical energy generated by a motor during braking into heat. However, the use of brake regulators is not limited to applications in electrically driven devices that perform braking. Therefore, braking energy is not necessarily energy converted into heat. Brake regulators can also be used, for example, to stabilize the power grid by converting electrical energy from the power grid into heat. The term "brake resistor" was chosen to distinguish it from other resistors that can convert a predetermined amount of electrical energy or power into heat or heat per unit time.

[0005] In the following text, the phrase "power to be converted into heat" refers to the conversion of the integral of power over time into heat. In other words, the total energy obtained by integrating power over time will be converted into heat. Summary of the Invention

[0006] The purpose of this invention is to improve the modular brake regulator.

[0007] This objective is achieved by a method for operating a modular brake regulator, wherein the modular brake regulator has at least two brake regulator branches, each of which has at least one submodule and a braking resistor, the submodule and the braking resistor being arranged in a series circuit; wherein the brake regulator branches are arranged in a parallel circuit between two terminals of the modular brake regulator; wherein at least for a portion of the time, at least two of the brake regulator branches generate voltages with alternating components via the respective at least one submodule, wherein the alternating components do not contain a DC component; wherein the alternating components of each brake regulator branch are mutually exclusive. The phase shift, where n corresponds to the number of brake regulator branches that generate the voltage, wherein all alternating components have the same amplitude and are designed to convert the electrical energy absorbed by the modular brake regulator over time into heat in the brake resistor. This objective is also achieved by a control device configured to perform this method. This objective is also achieved by a modular brake regulator having at least two brake regulator branches, each of which has at least one submodule and a brake resistor, the submodule and the brake resistor being arranged in a series circuit; wherein the brake regulator branches are arranged in a parallel circuit between two terminals of the modular brake regulator, wherein voltage can be generated by means of the at least one submodule of the respective brake regulator branch; wherein the modular brake regulator has such a control device for controlling or regulating the at least one submodule of the respective brake regulator branch. Furthermore, this objective is also achieved by a modular drive unit having a modular multilevel converter and such a modular brake regulator, wherein the modular brake regulator is electrically connected to the DC voltage side of the modular multilevel converter.

[0008] Other advantageous designs of the invention are given in the dependent claims.

[0009] This invention is particularly based on the understanding that, through the modular structure of the modular brake regulator, any operating voltage of the brake regulator can be achieved. Typically, the modular brake regulator is connected to the intermediate circuit of the converter to convert electrical energy from the drive system or power supply system into heat. Through its modular structure, the modular brake regulator can be adapted to arbitrarily high intermediate circuit voltages by using a corresponding number of sub-modules.

[0010] The brake regulator structure includes at least two brake regulator branches arranged in parallel between the terminals of the modular brake regulator, and each branch has at least one submodule and a series circuit with a braking resistor. The number of submodules in each brake regulator branch is preferably chosen to be the same. This simplifies system adjustment. The resistance value of each brake regulator branch can also be chosen to be the same.

[0011] All known types of submodules can be used as submodules. These include, for example, half-bridge modules, dual half-bridge modules, or full-bridge modules. To generate voltage, the voltage of one or more capacitors of the respective submodule can be used. Alternatively, a voltage smaller than that of the capacitor or the voltage of multiple capacitors can be generated by the submodule, for example, by using pulse width modulation. Pulse width modulation has proven advantageous for generating different voltages, especially when using only one submodule.

[0012] Furthermore, the method for operating the modular brake regulator allows for precise control or regulation of the power to be converted into heat. The heat is derived from the integral of power over time. The method specifies that not all intermediate circuit voltages decrease during energy conversion at the braking resistor. Its advantage lies in the ability to regulate the power to be converted into heat. Simultaneously, the energy content of one or more capacitors in at least one or more sub-modules is adjusted. Therefore, the modular brake regulator can operate stably even over extended operating periods, especially during continuous operation.

[0013] The braking resistor can be placed anywhere in the series circuit within the brake regulator branch. For example, the braking resistor can be placed between one of the terminals of a modular brake regulator and a submodule, or anywhere between two submodules.

[0014] If the modular brake regulator is not activated, i.e., there is no need to convert electrical energy into heat, the voltage applied to at least one submodule of all brake regulator branches or to a further series circuit of the submodule is the same as the intermediate circuit voltage. Therefore, there is no voltage drop across the resistor, and thus no current flows. Only a portion (but at least two) of the brake regulator branches can be operated in a manner that converts electrical energy into heat, while the remaining brake regulator branches are unloaded and the submodule at that point generates the intermediate circuit voltage, thus no current flows. The brake regulator branches involved in energy conversion generate an alternating component and are therefore referred to as voltage-generating brake regulator branches.

[0015] For control or regulation, a voltage is generated on at least one submodule of the voltage-generating brake regulator branch, or, if multiple submodules are arranged in a further series circuit, a voltage is generated on the further series circuit of these submodules. A DC component of the voltage is provided for controlling or regulating the power to be converted into heat. This DC component generates a current with a further DC component through the modular brake regulator. How this further DC component is distributed across the various voltage-generating brake regulator branches is not important. For the uniform utilization of the brake regulator branches, it is advantageous to distribute this additional DC component evenly across the voltage-generating brake regulator branches. Therefore, the DC components of the generated voltages are equal in the voltage-generating brake regulator branches.

[0016] To adjust the voltage of one or more capacitors in one or more submodules, an alternating component is superimposed on the DC component.

[0017] In this circuit, each of the braking regulator branches that generates voltage produces an alternating component. The amplitude of the alternating component is the same in each of the different voltage-generating braking regulator branches, but the phase is different. The alternating components of the different voltage-generating braking regulator branches have phase differences between each other. The phase difference. Where n corresponds to the number of brake regulator branches that generate the voltage. This ensures that the generated AC current is formed only within the modular brake regulator. This reliably avoids interference with components connected to the brake regulator (such as converters or motors).

[0018] Of particular advantage is the combination of modular brake regulators and modular multilevel converters (also known as M2C converters) into modular drive units. Structurally identical submodules can be used in both the modular multilevel converter and the modular brake regulator. Similarly, the same hardware can be used to control the submodules. Because both the converter and the modular brake regulator employ a modular structure, the modular drive unit can be easily adapted to the required power requirements by selecting the appropriate number of submodules from the converter and the modular brake regulator. Since the submodules in the modular brake regulator and the multilevel converter have identical structures, a high proportion of identical components can be achieved. This has a positive impact on the reliability and manufacturing cost of such drive units.

[0019] Modular brake regulators can be connected to the DC voltage side of converters with arbitrary structures and are not limited to use with modular multilevel converters.

[0020] Using the DC component of the voltage, a current is generated through a modular brake regulator, which also has a further DC component. This DC component flows through the modular brake regulator and thus through the braking resistor. The current flowing through the braking resistor generates electrical losses. These losses are used to selectively convert electrical energy into heat. The amount of power converted into heat (i.e., energy per unit time) can be controlled or adjusted by the magnitude of the DC component of the voltage, as this directly yields the voltage drop across the resistor and thus the further DC component of the current flowing through the modular brake regulator.

[0021] An intermediate circuit voltage is applied to the modular brake regulator because the regulator is electrically connected to the intermediate circuit. Therefore, the intermediate circuit voltage is applied to a series circuit consisting of the braking resistor and a further series circuit of the submodule. Alternatively, only one submodule can be provided as an alternative to the further series circuit of the submodule. Thus, the modular brake regulator with the applied intermediate circuit voltage absorbs active power.

[0022] All active power absorbed by the braking resistor should be converted into heat, because modular brake regulators should not be designed to absorb and store large amounts of energy. Here, n also corresponds to the number of brake regulator branches that generate voltage.

[0023] The alternating components of each voltage-generating brake regulator branch are designed such that the electrical energy absorbed by the modular brake regulator over time is converted into heat in the braking resistor. These alternating components can influence the voltage of the capacitors in the submodule and stabilize the modular brake regulator. The alternating voltage component, through the corresponding voltage drop across the braking resistor of the respective brake regulator branch, generates a further alternating component in the current within the modular brake regulator; this further alternating component does not flow through the terminals of the modular brake regulator. The resulting alternating components circulate only within the modular brake regulator and are not visible from the outside.

[0024] The average values ​​of both the alternating component and the further alternating component are zero, so only reactive power is exchanged between the further alternating component of the current and the intermediate circuit voltage or the voltage on the modular braking regulator. Therefore, the alternating component contains no DC component. It has been advantageously shown that this component can be used to exchange energy between the capacitors and resistors of the submodule. The energy exchange is advantageously controlled or regulated such that all active power on the resistor is converted into heat. The electrical energy absorbed by the modular braking regulator over time is converted into heat in the braking resistor. Expressed by a formula, the relationship is:

[0025] Among them, the current i through the braking resistor of each braking regulator branch BR From DC component i BR,DC and alternating component i BR,aDC according to

[0026] Composition. Therefore, the alternating component can be determined based on the voltage waveform that affects the effective value.

[0027] As the braking resistor, a common resistor with a sufficiently large parasitic inductance is preferred. If the inductance is too small, an additional inductor connected in series with the submodule or resistor can optionally be installed in the braking regulator branch. The loop current can be selectively injected and regulated by modulating the voltage drop across the parasitic inductance and / or the external inductor.

[0028] When using the proposed method, even with a high-power brake regulator, the converter connected to the DC grid or intermediate circuit of the drive system does not require separate design or functional expansion for brake regulator operation. This means that for conventional converters used in conjunction with unit-based brake choppers, component selection and consideration are only needed for stable converter operation. Furthermore, the proposed method and corresponding apparatus also enable operation using passive converters (e.g., diode rectifiers). This has been impossible until now because loop current cannot form a closed loop through a diode rectifier. The proposed structure enables fully autonomous brake regulator operation; the brake regulator can also be installed as a protection component at any location within the DC grid or transmission line.

[0029] In an advantageous embodiment of the invention, each brake regulator branch includes multiple sub-modules arranged in a further series circuit, wherein the voltage generated by the multiple sub-modules is applied to the further series circuit of the sub-modules. By using multiple sub-modules in the further series circuit, the operating voltage of the modular brake regulator can be arbitrarily adapted to the intermediate circuit voltage of the converter. This allows for arbitrarily high operating voltages, i.e., the intermediate circuit voltage in the drive unit.

[0030] It has been proven advantageous to select the same number of submodules in each brake regulator branch. This simplifies the control and regulation process, particularly because energy balance is easily established relative to the energy stored in the submodule capacitors. This allows the complex structure to operate stably.

[0031] In another advantageous embodiment of the invention, the voltage generated by the braking regulator branch has a DC component, which is controlled or regulated based on the power to be converted into heat by the modular braking regulator, or based on the voltage applied to the modular braking regulator. Both the power to be converted into heat and the voltage applied to the modular braking regulator can be set, for example, by means of a setpoint. Regulation can be performed simply, for example, by a PI regulator, by comparing the setpoint with an actual value. Therefore, it has proven advantageous to control or regulate the DC component based on the power to be converted into heat. This power can also depend on other variables, such as the voltage of the capacitors in the sub-modules of the modular multilevel converter. If the modular braking regulator operates on an intermediate circuit with intermediate circuit capacitors, for example, on a two-level or three-level converter, it has proven advantageous to control or regulate the DC component based on the intermediate circuit voltage. Using these regulating structures, dynamic regulation for converting electrical power into heat can be achieved, which protects the electric drive unit from overload due to excessive energy. This energy can, for example, come from the braking process of the motor.

[0032] It has been proven advantageous to generate the DC component of all brake regulator branches with the same magnitude. In this case, the further DC component of the current will also be evenly distributed across each brake regulator branch generating voltage. This results in a more uniform load on each brake regulator branch, thus achieving more uniform aging. This contributes to a longer service life for the modular brake regulator.

[0033] In another advantageous embodiment of the invention, the DC component is controlled or regulated to generate a current with a further DC component via a modular brake regulator. The product of the further DC component of all brake regulator branches generating voltage and the voltage on the modular brake regulator corresponds to a predetermined power to be converted into heat by the modular brake regulator, particularly a predetermined active power to be converted into heat by the modular brake regulator. The magnitude of the DC component of the voltage is controlled or regulated such that the further DC component of the current reaches a corresponding magnitude, which makes the product of the intermediate circuit voltage and the further DC components of all brake regulator branches correspond to the value of the power to be converted into heat by the modular brake regulator. The power to be converted into heat refers to the energy converted into heat within a certain time. Alternatively, the active power can also be defined as the power to be converted into heat.

[0034] In another advantageous embodiment of the invention, the alternating component is used as a manipulated variable to regulate the voltage of the submodule capacitor. To eliminate interference, it has proven advantageous to use the value of the alternating component, determined according to a formula, for feedforward control. The voltage across the capacitor is then regulated. Therefore, the modular braking regulator operates stably even in the presence of interference. Furthermore, this operation is unaffected by changing parameters. For example, changes in resistance caused by aging or temperature rise can be easily compensated for through adjustment.

[0035] In another advantageous embodiment of the invention, the AC voltage side of the modular multilevel converter is connected to an energy source, particularly to a power grid or a motor. By connecting to an energy source, the modular brake regulator can be used to convert excess or unavailable energy into heat. For example, the energy source could be a motor that feeds back electrical energy during braking. If this electrical energy cannot be further utilized, it must be converted into heat using a modular brake regulator when the mechanical brake is to be abandoned. Unlike mechanical brakes, the conversion of electrical energy into heat is wear-free, thus making the modular brake regulator more economical to use in operation.

[0036] Modular multilevel converters can also be used for energy transfer. In this case, where the transferred energy cannot be absorbed, a modular braking regulator may be appropriate. This modular braking regulator ensures that such energy transfer continues even if energy reception is disrupted. The energy transfer system can remain operational during such disruptions and reliably avoid complex restarts and shutdowns that could lead to stability issues in the power grid. Therefore, the modular braking regulator also improves the reliability and availability of the modular drive units used for energy transfer.

[0037] In another advantageous embodiment of the invention, the control device of the modular drive unit is configured to determine the power to be converted into heat based on the voltage of the capacitors of the sub-modules of the modular multilevel converter. In a modular multilevel converter, the energy stored in the converter is not necessarily reflected in the intermediate circuit voltage as in, for example, a two-level or three-level converter. In a modular multilevel converter, increased energy content affects the stored energy, i.e., the voltage, of one or more capacitors in the corresponding sub-module. To specifically reduce the energy content in the modular multilevel converter, it has proven advantageous to determine the power to be converted into heat for controlling or regulating the DC component based on the voltage of the capacitors of each sub-module of the modular multilevel converter. A possible method for operating an electric drive unit having a modular converter and the proposed modular brake regulator involves regulating or controlling the DC component of the voltage on a further series circuit of a sub-module of the modular brake regulator based on the voltage of one or more capacitors of the sub-module of the modular multilevel converter. Attached Figure Description

[0038] The present invention will be described and explained in more detail below with reference to the embodiments shown in the figures. Wherein: Figure 1 Modular brake regulator, Figures 2 to 4 Implementation examples of submodules, Figure 5 The time curves of voltage and current, Figures 6 to 8 An embodiment of a modular drive unit. Detailed Implementation

[0039] Figure 1 A modular brake regulator 1 is shown. It has multiple brake regulator branches 15 arranged in parallel between terminals 11 of the modular brake regulator 1. Each brake regulator branch 15 has at least one submodule 2 in a series circuit 4 with a braking resistor 3. The series circuit 4 may have multiple submodules 2. These submodules are arranged as part of a further series circuit 41. The modular brake regulator 1 is configured to be connected to the intermediate circuit 9 of the converter at its terminals 11.

[0040] With the help of control device 10, a voltage u can be generated on the further series circuit 41 of submodule 2. BR Using the generated voltage u BR Current i can be generated through the modular brake regulator 1. BR Current i BR It also flows through the corresponding braking resistor 3, converting electrical energy into heat. At terminal 11, the current iBR Summarized as total current I BR Preferably, the current i BR They are adjusted to be identical in all aspects except for phase.

[0041] A running voltage U is applied to the modular brake regulator 1. D If the modular brake regulator 1 is connected to the intermediate circuit of the converter, then the intermediate circuit voltage is applied to the modular brake regulator. In this case, it is considered that the modular brake regulator 1 is connected to the DC voltage side of the converter.

[0042] Figures 2 to 4 An embodiment of submodule 2 is shown. All known submodule 2, especially... Figures 2 to 4 Submodule 2 is suitable for executing the proposed methods. To avoid duplication, see [link to relevant documentation]. Figure 1 The description and the reference numerals introduced therein.

[0043] The embodiment of submodule 2 shown includes at least two semiconductor switches and at least one capacitor. An output voltage U can be generated at the terminals of submodule 2 by switching the semiconductor switches. sub The control device 10 transmits control signals to the semiconductor switches of the submodule 2. The control device 10 is preferably located outside the submodule 2 and is therefore not part of the submodule 2. More specifically, it has proven advantageous to use a single control device 10 to control all submodules 2 of the modular brake regulator 1. Furthermore, the control device 10 can perform the calculations required for controlling and regulating voltage and current. Therefore, the control device 10 can determine the required current i flowing through the modular brake regulator 1 based on a predetermined value of the power to be converted into heat. BR To generate this current i BR Through corresponding control signals, a voltage determined, controlled, or regulated by the control device 10 is generated on submodule 2 of the further series circuit 41. In the following embodiments, illustrations of the control device 10 are omitted for clarity.

[0044] Figure 2 This illustrates a so-called half-bridge module. It has two semiconductor switches and one capacitor. A voltage U is applied across the capacitor. C,sub By switching on a semiconductor switch, a value of zero or U can be generated at the terminals of submodule 2. C,sub Output voltage U sub .

[0045] Figure 3 This illustrates a so-called dual-bridge module. It has four semiconductor switches and two capacitors. A voltage U is applied to each capacitor. C1,sub or U C2,subBy switching on a semiconductor switch, a voltage U, which is zero and acts as a capacitor, can be generated at the terminals of submodule 2. C1,sub U C2,sub One of them is the voltage U of the capacitor. C1,sub U C2,sub The sum of the output voltage U sub .

[0046] Figure 4 This illustrates a so-called full-bridge module. It has four semiconductor switches and one capacitor. A voltage U is applied across the capacitor. C,sub By switching on a semiconductor switch, a capacitor voltage ±U can be generated at the terminals of submodule 2, which can be zero, positive, or negative. C,sub Output voltage U sub .

[0047] Figure 5 The voltage u generated in the further series circuit is shown. BR and the current i flowing through the modular brake regulator 1 BR The selection of possible time curves. Among them, the alternating component u BR,aDC It can be sinusoidal. Alternatively, the alternating component u... BR,aDC It can also be obtained by superimposing two sinusoidal functions of different frequencies. As a further alternative, the alternating component u... BR,aDC The voltage and current waveforms can be square or trapezoidal. All of these design schemes can be used to control or regulate modular brake regulators.

[0048] Figure 6 A modular drive unit 20 is shown, comprising a modular multilevel converter 21 and a modular brake regulator 1. They are interconnected via an intermediate circuit 9 to which a voltage UD is applied. The modular multilevel converter 21 may, but does not necessarily, have the same sub-module 2 as the modular brake regulator 1. Furthermore, the series circuit of the sub-module 2 of the modular multilevel converter 21 includes an inductor 8, which improves the regulation characteristics of the modular multilevel converter 21. Terminals L1, L2, and L3 represent the AC voltage side terminals of the modular multilevel converter 21, or simply the AC voltage side. In this embodiment, the modular multilevel converter 21 is a three-phase structure. Alternatively, a single-phase structure with a neutral line or any number of phases can be achieved by providing corresponding multiple phase modules in the modular multilevel converter 21.

[0049] Figure 7 An embodiment of the modular drive unit 20 is shown. The energy source 5 is electrically connected to the AC voltage side of the modular multilevel converter 21. The energy source may be, for example, a power grid 6 or a motor 7.

[0050] exist Figure 8 In this embodiment, the modular drive unit 20 has two modular multilevel converters 21 and a modular brake regulator 1, which are electrically connected to each other on an intermediate circuit 9. The first of the two modular multilevel converters 21 is connected to the power grid 6 on its AC voltage side, and the second of the two modular multilevel converters 21 is connected to the motor 7 on its AC voltage side. The motor 7 can be powered by the power grid 6. Using the modular drive unit 20, energy can also be fed back from the motor 7 to the power grid 6, for example, during braking. If the power grid 6 lacks absorption capacity, the electrical energy obtained through the motor 7 can be advantageously converted into heat using the modular brake regulator 1. In this design, the easily worn mechanical brake can be omitted.

Claims

1. A method for operating a modular brake regulator (1), wherein, The modular brake regulator (1) has at least two brake regulator branches (15), each of which has at least one submodule (2) and a braking resistor (3), the submodule (2) and the braking resistor (3) being arranged in a series circuit (4); wherein the brake regulator branches (15) are arranged in a parallel circuit between two terminals (11) of the modular brake regulator (1); wherein at least for a portion of the time, at least two of the brake regulator branches (15) generate an alternating component (u) by means of the corresponding at least one submodule (2). BR,aDC voltage (u) BR ), wherein the alternating component (u BR,aDC ) does not contain a DC component; wherein the alternating component (u) of each brake regulator branch (15) is... BR,aDC ) have each other The phase shift, where n corresponds to the number of the braking regulator branch (15) that generates the voltage, where all alternating components (u BR,aDC The amplitudes are the same, and it is designed to convert the electrical energy absorbed by the modular brake regulator (1) over time into heat in the brake resistor (3).

2. The method according to claim 1, wherein, The direct current component (u BR,DC ) is used to control or regulate the power to be converted into heat; wherein the alternating component (u BR,DC ) superimposed on the direct current component (u BR,aDC ) is used to regulate the voltage of the capacitor of the sub-module (2) or the plurality of sub-modules (2) or the voltage of the plurality of capacitors.

3. The method according to any one of claims 1 or 2, wherein, The brake regulator branches (15) each comprise a plurality of submodules (2) which are arranged in a further series circuit (41); wherein the voltage (u BR ) generated by means of the plurality of submodules (2) is applied to the further series circuit (41) of the submodules (2).

4. The method according to any one of claims 1 to 3, wherein, The voltage (u BR ) generated by the voltage-generating brake modulator branch (15) has a direct current component (u BR,DC ); wherein the direct current component (u BR,DC ) is controlled or regulated as a function of the power to be converted into heat by the modular brake modulator (1), or as a function of the voltage (U D ) applied to the modular brake modulator (1).

5. The method according to claim 4, wherein, For the DC component (u) BR,DC The modular brake regulator (1) is controlled or regulated to generate a further DC component (i) through the modular brake regulator (1). BR,DC The current (i) BR ); wherein the further DC component (i) of all the braking regulator branches (15) that generate voltage BR,DC ) and the voltage (U) on the modular brake regulator (1) D The product of ) corresponds to the predetermined power to be converted into heat by the modular brake regulator (1), in particular the predetermined active power to be converted into heat by the modular brake regulator (1).

6. The method according to any one of claims 1 to 5, wherein, The alternating component (u) BR,aDC The voltage (U) used as the capacitor of the submodule (2) C,sub Manipulated variables used for adjustment.

7. A control device (10) configured to perform the method according to any one of claims 1 to 6.

8. A modular brake regulator (1), wherein, The modular brake regulator (1) has at least two brake regulator branches (15), each of which has at least one sub-module (2) and a brake resistor (3), the sub-module (2) and the brake resistor (3) being arranged in a series circuit (4); wherein the brake regulator branch (15) is arranged in a parallel circuit between two terminals (11) of the modular brake regulator (1); wherein the voltage (u) BR The modular brake regulator (1) can be generated by means of at least one submodule (2) of the corresponding brake regulator branch (15); wherein the modular brake regulator (1) has a control device (10) according to claim 7 for controlling or regulating the at least one submodule (2) of the corresponding brake regulator branch (15).

9. The modular brake regulator (1) according to claim 8, wherein, The brake regulator branch (15) includes multiple sub-modules (2) arranged in a further series circuit (41), wherein the voltage (u) generated by means of the multiple sub-modules (2) is... BR ) is applied to the further series circuit (41).

10. A modular drive unit (20) having a modular multilevel converter (21) and a modular brake regulator (1) according to any one of claims 8 or 9, wherein the modular brake regulator (1) is electrically connected to the DC voltage side of the modular multilevel converter (21).

11. The modular drive unit (20) according to claim 10, wherein, The AC voltage side of the modular multilevel converter (21) is connected to an energy source (5), particularly to a power grid (6) or a motor (7).

12. The modular drive unit (20) according to any one of claims 10 or 11, wherein, The control device (10) is configured to determine the power to be converted into heat based on the voltage of the capacitors of the sub-modules of the modular multilevel converter (21).

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