Control device for a DC voltage converter, DC voltage converter and method for controlling a DC voltage converter

Abstract

The present invention provides a regulation for a DC voltage converter (10) having a plurality of DC voltage converter modules (4-1, 4-2). To this end, a central regulation variable for voltage-controlled regulation of the DC voltage converter is generated for all DC voltage converter modules. In addition, a current-based regulation variable can be additionally generated for each DC voltage converter module. By combining the voltage-based regulation variable with the current-based regulation variable, the output power, in particular the output current, of each DC voltage converter module can be uniquely adjusted. In this way, overloading of the DC voltage converter modules can be avoided.

Description

Technical Field

[0001] The invention relates to a regulating device for a DC voltage converter, in particular a DC voltage converter having a plurality of DC voltage converter modules, a DC voltage converter having such a regulating device, and a method for regulating a DC voltage converter. Background Art

[0002] Publication DE 10 2016 219 740 A1 discloses a DC voltage converter having a plurality of DC voltage converter modules connected in parallel. Here, a common voltage regulator is provided for all DC voltage converter modules. In addition, a separate current regulation is provided for each DC voltage converter module.

[0003] The DC voltage converter is configured to convert an input DC voltage into an output DC voltage, wherein the voltage level of the input DC voltage can be different from the voltage level of the output DC voltage. The maximum output power of the DC voltage converter is limited by the size of the components used. In order to increase the output power, a plurality of DC voltage converter modules can be connected in parallel if necessary. Summary of the invention

[0004] The invention discloses a control device for a DC voltage converter, a DC voltage converter and a method for controlling a DC voltage converter having the features of the independent claims. Further advantageous embodiments are the subject matter of the dependent claims.

[0005] Accordingly, it provides:

[0006] A regulating device for a DC voltage converter having a plurality of DC voltage converter modules. The regulating device includes a pre-control mechanism and a plurality of current regulators. In particular, a separate current regulator is assigned to each DC voltage converter module of the DC voltage converter. The pre-control mechanism is designed to generate a first regulating variable. In particular, the pre-control mechanism can generate a first regulating variable using a rated value for an output voltage of the DC voltage converter and a calculated value for an input voltage of the DC voltage converter. The plurality of current regulators are respectively designed to generate a separate second regulating variable for the DC voltage converter modules respectively assigned. Each current regulator is respectively designed to: calculate a corresponding regulating variable using a calculated value for a current in the DC voltage converter modules respectively assigned and a predetermined maximum current for the corresponding DC voltage converter modules. In addition, the regulating device for the DC voltage converter is designed to: provide a combination of a first regulating variable and a second regulating variable for the DC voltage converter modules respectively assigned on the DC voltage converter modules.

[0007] Also provided:

[0008] A DC voltage converter having a plurality of DC voltage converter modules and a

[0009] The regulating device for the DC voltage converter of the present invention. Each DC voltage converter module in the DC voltage converter module is designed to convert an input DC voltage into an output DC voltage. In addition, a separate current regulator is provided for each DC voltage converter module in the DC voltage converter in the regulating device.

[0010] Finally provided:

[0011] A method for regulating a DC voltage converter having a plurality of DC voltage converter modules. The method comprises a step for generating a first regulating variable using a rated value for an output voltage of the DC voltage converter and a determined value for an input voltage of the DC voltage converter. In addition, the method comprises a step for generating a plurality of unique second regulating variables, wherein a separate second regulating variable is generated for each DC voltage converter module of the DC voltage converter. The respective second regulating variables are generated in particular using a determined value for a current of a respectively assigned DC voltage converter module and a predetermined maximum current for the respective DC voltage converter module. Finally, the method comprises the following steps, which are used to combine the first regulating variable and the second regulating variable for the respectively assigned DC voltage converter module and to provide the respective combined regulating variables on the respective DC voltage converter module.

[0012] Advantages of the present invention

[0013] The present invention is based on the following recognition, that is, a DC voltage converter can usually only provide a limited maximum output power. If a plurality of individual DC voltage converter modules are connected in parallel in a DC voltage converter, then in this case the output power of each individual DC voltage converter module is limited. Overloading of the DC voltage converter, in particular the DC voltage converter module, can lead to damage to the corresponding DC voltage converter module.

[0014] Therefore, the idea of ​​the present invention is to take this knowledge into account and limit the maximum output current of each DC voltage converter module in a DC voltage converter having a plurality of DC voltage converter modules. In this way, even in the case of a high power demand on the output side of the DC voltage converter, the power output of the DC voltage converter, in particular the power output of each individual DC voltage converter module of a DC voltage converter having a plurality of DC voltage converter modules connected in parallel, can be limited to a permissible extent. In this way, damage to the individual DC voltage converter modules due to overload can be avoided.

[0015] For this purpose, it is provided that, on the one hand, the output voltage of a DC voltage converter having a plurality of DC voltage converter modules connected in parallel is controlled centrally by a common pre-control mechanism. In addition, in order to limit the power of each DC voltage converter module, a separate current regulator is provided for each DC voltage converter module of the DC voltage converter. By means of separate current regulators for a plurality of DC voltage converter modules of the DC voltage converter, the power output can be adjusted uniquely by limiting the maximum output current of the corresponding DC voltage converter module. Here, the generated regulation variable of the pre-control mechanism for the corresponding DC voltage converter module is reduced by the regulation variable of the current regulator.

[0016] In this way, it is possible that the central pre-control mechanism first generates a first control variable. Based on this first control variable, the individual DC voltage converter modules can be controlled in such a way that the rated voltage to be obtained is provided at the output of the corresponding DC voltage converter module. However, if the following power requirements are generated under the desired rated voltage due to the configuration at the output of the DC voltage converter, which power requirements may lead to an inadmissibly high output current at the DC voltage converter module of the DC voltage converter, the first control variable of the central pre-control mechanism can be superimposed by the unique second control variable of the current regulator by means of the respective assigned current regulator of the corresponding DC voltage converter module. In this way, the output power of the corresponding DC voltage converter module is limited so that the maximum output current is not exceeded on the corresponding DC voltage converter module.

[0017] This power limitation or current limitation of each DC voltage converter module can be explained by taking the capacitor at the output end of the DC voltage converter as an example. If the DC voltage converter with multiple DC voltage converter modules provides the necessary adjustment amount for reaching the output voltage at the beginning of the charging process of the capacitor, a very high charging current for the capacitor will appear at the beginning of this charging process. This high charging current may overload one or more of the DC voltage converter modules. Therefore, the control amount for the pre-control mechanism is superimposed by the appropriate initialization of the corresponding current regulator for each DC voltage converter module, so as to limit the maximum output current of each DC voltage converter module to the maximum current value. In this case, a lower output voltage is first generated at the output end of the DC voltage converter during the charging process. When the capacitor is charged with the maximum current of each DC voltage converter module, the voltage at the output end of the DC voltage converter rises and the voltage on the capacitor rises in the further process of the charging process. If the voltage on the capacitor is close to the target value, the charging current drops here. In this process, the limitation of the current in the DC voltage converter module by the corresponding current regulator is cancelled. In other words, the second manipulated variable of the current regulator for the DC voltage converter module approaches zero and the first manipulated variable of the pilot control is applied to the DC voltage converter module without further superposition of the second manipulated variable for current limiting.

[0018] According to one embodiment, the regulating device includes a voltage regulator. The voltage regulator can be designed to generate a third regulating variable using a setpoint value for the output voltage of the DC voltage converter and an ascertained value of the output voltage of the DC voltage converter. In this way, the current output voltage can also be taken into account for regulating the DC voltage converter.

[0019] According to one embodiment, the voltage regulator includes a two-point regulator. For example, the voltage regulator can be an I regulator, that is, a regulator without a P part with a purely integrated regulation characteristic, etc. The voltage regulator can be operated at two operating points, for example. In the first operating point, the voltage regulator can output a third regulation amount, which is suitable for promoting the current flow in the DC voltage converter module when the output voltage of the DC voltage converter is lower than a predetermined first threshold value. In the second operating point, the voltage regulator can output a third regulation amount, which is suitable for deactivating the current flow in the DC voltage converter module when the output voltage of the DC voltage converter exceeds a predetermined second threshold value. For this purpose, for example, the value of the third regulation amount can be reduced so that the DC voltage converter module does not output current subsequently. If or as long as the output voltage of the DC voltage converter is lower than a predetermined threshold value, the voltage regulator can be operated in the first operating point in particular. That is, the third regulation amount output by the voltage regulator promotes the current flow in the DC voltage converter module until a predetermined threshold value is reached at the output end of the DC voltage converter. If the output voltage of the DC voltage converter exceeds a predetermined threshold value, the voltage regulator can be transformed into a second operating point. Subsequently, the third regulation amount of the voltage regulator is reduced so that it does not cause current flow in the DC voltage converter module. If the voltage at the output of the DC voltage converter drops below another threshold value in a further process, the voltage regulator can then be transformed into the first operating point again. Here, the other threshold value is lower than the previously cited predetermined threshold value with a hysteresis or an offset. Thus, an almost constant voltage at the output of the DC voltage converter can be maintained in a simple manner.

[0020] According to one embodiment, each current regulator for each assigned DC voltage converter module is designed to limit the output current of the assigned DC voltage converter module to a predetermined maximum current. In this way, overloading of the corresponding DC voltage converter module can be prevented. In particular, in the same or similar embodiments of the DC voltage converter module, the current regulator can limit the output current of the DC voltage converter module to a common maximum current. As an alternative, it is also possible to use different or differently manufactured DC voltage converter modules in the DC voltage converter. In this case, each current regulator can use a unique maximum output current to limit the maximum current in the corresponding DC voltage converter module.

[0021] According to one specific embodiment of the DC voltage converter, the DC voltage converter can be designed to be coupled to a capacitor at the output of the DC voltage converter. In particular, the DC voltage converter can be coupled, for example, to an intermediate circuit capacitor of an electrical rectifier, for example an inverter.

[0022] According to one specific embodiment, the regulating device is designed to deactivate the current regulator when a predetermined output voltage is reached at the output of the DC voltage converter.

[0023] As long as it makes sense, the above-mentioned designs and improvements can be combined with each other arbitrarily. Other designs, improvements and implementations of the present invention also include combinations of features not explicitly mentioned before or below described in relation to the embodiments of the present invention. Here, those skilled in the art will also add individual aspects as improvements or supplements to the corresponding basic forms of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Further features and advantages of the present invention are explained below with the aid of the accompanying drawings.

[0025] Figure 1 A schematic diagram showing a basic circuit diagram of a DC voltage converter having a regulating device according to one embodiment;

[0026] Figure 2 shows a schematic diagram of a circuit arrangement having a DC voltage converter according to one embodiment; and

[0027] Figure 3 A flow chart is shown as a basis for a method for controlling a DC voltage converter according to one specific embodiment. DETAILED DESCRIPTION

[0028] Figure 1 A schematic diagram of a principle circuit diagram of a DC voltage converter 10 with a regulating device 11 according to an embodiment is shown. The DC voltage converter 10 includes a plurality of DC voltage converter modules 4-i. Although only two DC voltage converter modules 4-1 and 4-2 are shown in the illustrated embodiment, the DC voltage converter 10 can include any number of DC voltage converter modules 4-i. Each DC voltage converter module 4-i can be fed with a DC voltage on the input side. The DC voltage converter module 4-i converts the DC voltage provided on the input side into another DC voltage and provides the converted DC voltage at the output end. Here, all DC voltage converter modules 4-i should provide the same level of DC voltage on the output side.

[0029] The output voltage of the DC voltage converter module 4-i is adjusted according to the adjustment variable. For this purpose, a unique adjustment variable can be provided on each DC voltage converter module 4-i. The adjustment variable is generated by means of the adjustment device 11. The structure and functional principle of this adjustment device 11 will be explained in more detail below.

[0030] The regulating device 11 includes a central pilot control mechanism 1. In addition, the regulating device 11 includes a corresponding current regulator 2-i for each DC voltage converter module 4-i. Optionally, the regulating device 11 can also include a central voltage regulator 3. The DC voltage converter module 4-i is regulated accordingly based on the central first regulating variable R1 of the pilot control mechanism 1, if necessary in combination with another regulating variable R3 of the central voltage regulator 3 and the respective unique regulating variables R2-i of the current regulator 2-i. This regulating scheme will be explained in more detail below.

[0031] In addition to the setpoint value U_setpoint for the output voltage of the DC voltage converter 10, a parameter U_In can be provided to the pilot control device 1, which corresponds to the input voltage of the DC voltage converter 10. In other words, the parameter U_In corresponds to the voltage value at the input of the DC voltage converter module 4-i. If necessary, other parameters such as the value of the input current or output current of the DC voltage converter module 4-i can also be provided to the pilot control device 1. The pilot control device 1 determines the first control variable R1 based on the input value of the pilot control device 1.

[0032] The central voltage regulator 3 provides a variable U_target value for the output voltage of the DC voltage converter 10. The voltage regulator 3 also receives a variable U_Ist, which corresponds to the current output voltage of the DC voltage converter 10. Based on these two variables U_target and U_Ist, the voltage regulator 3 generates a further manipulated variable R3.

[0033] The first manipulated variable R1 and the further manipulated variable R3 can be combined to form a common manipulated variable, for example, by means of a summing element A1 .

[0034] As already cited above, the regulating device 11 includes a unique current regulator 2-i for each DC voltage converter module 4-i. A parameter I_Ist-i is provided on each current regulator 2-i, which corresponds to the current of the corresponding DC voltage converter module 4-i. For example, the parameter I_Ist-i can correspond to the output current from the corresponding DC voltage converter module 4-i. As an alternative, it is also possible to detect the input current flowing into the DC voltage converter module 4-i and provide the corresponding parameter on the corresponding current regulator 2-i. Similarly, in principle, other parameters can also be provided on the corresponding current regulator 2-i, which correspond to the current flowing into or out of the corresponding DC voltage converter module 4-i. In addition, a rated parameter, especially the maximum allowed current I_max-i, can be provided on the current regulator 2-i. The corresponding current regulator 2-i generates a second regulating quantity R2-i from the parameter I_Ist-i for the current in the corresponding DC voltage converter module 4-i and the rated value I_max-i. This manipulated variable R2-i can be combined with the first manipulated variable R1 from the pilot control and, if necessary, with a further manipulated variable R3 from the voltage regulator. For example, the manipulated variables R1, R3 can be combined with the corresponding second manipulated variable R2-i in a respective further summing element A2-i. The combination of the manipulated variables can then be provided to the corresponding DC voltage converter 4-i.

[0035] In this way, it is possible to overmodulate the first manipulated variable R1 or the combination of the first manipulated variable R1 and the further manipulated variable R3 by the current regulator 2 - i by means of the second manipulated variable R2 - i of the respective current regulator 2 - i. As a result, the maximum current in or from the respective DC voltage converter module 4 - i can be limited.

[0036] If the current in the corresponding DC voltage converter module 4-i or the current from the DC voltage converter module 4-i is lower than the maximum current I_max-i, the corresponding second control variable R2-i approaches zero. In this case, the first control variable R1 or the combination of the first control variable R1 and the further control variable R3 is not affected by the corresponding second control variable R2-i. Therefore, if the current of the corresponding DC voltage converter module 4-i is lower than the maximum current I_max, the regulation in the output voltage U is performed only by the first control variable R1 of the pilot control mechanism 1, and if necessary, in combination with the further control variable R3 of the voltage regulator 3.

[0037] The voltage regulator 3 can be, for example, a two-point regulator. In particular, the voltage regulator 3 can be an I regulator, that is, a regulator with a purely integrated regulation characteristic without a P part, etc. The voltage regulator 3 can be operated, for example, at two operating points. In the first operating point, the voltage regulator 3 can output a regulation amount R3, which is suitable for promoting the current flow in the DC voltage converter module 4-i. In the second operating point, the voltage regulator 3 can output a regulation amount R3, which is suitable for deactivating the current flow in the DC voltage converter module 4-i. For this purpose, for example, the value of the first regulation amount R3 can be reduced so that the DC voltage converter module 4-i does not output current subsequently. If or as long as the output voltage of the DC voltage converter 10 is lower than a predetermined threshold value, the voltage regulator 3 can be operated, in particular, at the first operating point. That is, the regulation amount R3 output by the voltage regulator 3 always promotes the current flow in the DC voltage converter module 4-i until a predetermined threshold value is reached at the output end of the DC voltage converter 10. If the output voltage of the DC voltage converter 10 exceeds a predetermined threshold value, the voltage regulator 3 can be switched to the second operating point. Then, another regulating variable R3 of the voltage regulator 3 is reduced so that the regulating variable does not cause current flow in the DC voltage converter module 4-i. If the voltage at the output of the DC voltage converter 10 drops below another threshold value in the further process, the voltage regulator 3 is subsequently switched to the first operating point again. Here, the other threshold value is lower than the previously cited predetermined threshold value with a hysteresis or an offset. Thus, an almost constant voltage at the output of the DC voltage converter 10 can be maintained in a simple manner.

[0038] The characteristics of the voltage regulator will be explained in detail again below. The voltage regulator 3, for example, only works when not all current regulators 2-i of the DC voltage converter module 4-i work at the same time. As explained before, the voltage regulator 3 can have a pure I part (that is, without P, ​​PI or part). The I part can be limited in terms of maximum and minimum values. The voltage regulator 3 can take negative or positive values. The voltage regulator 3 can become negative with the absolute value (Betrag) of the value of the first regulating quantity R1 of the pilot control mechanism 1. If, for example, the value R1 of the pilot control mechanism 1 is 0.7 (70%), the other regulating quantity R3 cannot become less than (-0.7). The maximum value of the other regulating quantity R3 of the voltage regulator 3 can, for example, have the value after the maximum duty cycle is deducted from the duty cycle of the pilot control mechanism 1. For example, if the maximum pulse duty factor is 0.93% (93%) and the first manipulated variable R1 of the pilot control 1 is 0.7 (70%), then the maximum value of the further manipulated variable R3 of the voltage regulator 2 is: 0.93-0.7 =0.23% (23%).

[0039] As long as the voltage regulator 1 is running in its first operating point, it integrates the regulation deviation (rated voltage-actual voltage) and multiplies this result by a factor. After the output voltage exceeds the threshold value, the voltage regulator 3 is transformed into the second operating point. Subsequently, the voltage regulator 3 outputs another regulation quantity R3, which is obtained by multiplying the negative first regulation quantity R1 of the pilot control mechanism 1 by another factor. If, for example, the first regulation quantity R1 is 0.7 and another factor = 0.9 is used, the regulation quantity is -0.7*0.9 =-0.63. The negative regulation quantity here means that the total duty cycle becomes so small that no current can flow and the voltage at the output end remains the same.

[0040] If the voltage at the output drops below another threshold value (e.g., the first threshold value minus the hysteresis), the voltage regulator 3 can be switched back to the first operating process and current can thus flow out of the DC voltage converter module 4-i again. In this way, the voltage at the output of the DC voltage converter 10 can be stabilized.

[0041] Figure 2 1 shows a schematic diagram of a circuit arrangement according to one specific embodiment having a DC voltage converter 10. In this case, the DC voltage converter 10 corresponds largely to the specific embodiment described above, so that all the above explanations also apply below.

[0042] As in Figure 2As can be seen in the figure, the DC voltage converter module 4-i of the DC voltage converter 10 can be fed by a DC voltage source 20, such as a battery. For example, the battery 20 can be a battery in a low-voltage power grid of a vehicle, especially an electric vehicle or a hybrid vehicle. On the output side, the DC voltage converter 10 can be connected to a capacitor 30, for example. The capacitor 30 can be an intermediate circuit capacitor of a rectifier, for example. For example, the rectifier with the intermediate circuit capacitor 30 can be a rectifier for an electric drive device of an electric vehicle or a hybrid vehicle. The intermediate circuit capacitor 30 can be coupled to the output terminal of the DC voltage converter module 4-i, for example, through a suitable disconnect switch 31. In this way, the discharged capacitor 30 can be charged to a predetermined voltage by the DC voltage source 20 through the DC voltage converter 10. If the DC voltage converter module 4-i is controlled by the precontrol mechanism 1 according to the first adjustment amount R1, so that the rated voltage U_Soll to be obtained is immediately applied to the output end of the DC voltage converter module 4-i at the beginning of the charging process, a very high current will be applied to the DC voltage converter module 4-i. In order to avoid the disproportionately high load of the DC voltage converter module 4-i at the beginning of the charging process, the corresponding current regulator 2-i can influence the first regulating quantity R1 or the combination of the first regulating quantity R1 and another regulating quantity R3 by means of the second regulating quantity R2-i. In this way, each DC voltage converter module 4-i can be controlled so that the output power from the DC voltage converter module 4-i is first limited so that the maximum allowed current I_max-i is not exceeded. If the voltage on the capacitor 30 approaches the rated voltage U_Soll to be obtained during the charging process, the charging current in the capacitor 30 decreases during the charging process. After the charging current from the DC voltage converter module 4-i to the capacitor 30 drops below the maximum current I_max-i, the second regulating quantity R2-i of the corresponding current regulator 2-i is close to the value zero, so that the regulating quantity is not further affected by the corresponding second regulating quantity R2-i. If necessary, the corresponding current regulator 2-i can be deactivated. After the capacitor has been charged to a predefined setpoint voltage U_Soll, a further charging can be provided by the DC voltage converter 10. For this purpose, a limitation of the output current by the current regulator 2 - i can be omitted.

[0043] The DC voltage converter module 4-i can be any DC voltage converter module. For example, the DC voltage converter module 4-i can be made as a step-up chopper or a step-down chopper. In addition, the DC voltage converter module 4-i can also be a combined step-up-step-down chopper. In this case, in order to control the corresponding DC voltage converter module 4-i, the corresponding operating mode, that is, the step-up chopper mode or the step-down chopper mode, can also be considered together. In particular, the transition from the step-down chopper mode to the step-up chopper mode (or in the opposite direction if necessary) can also be considered.

[0044] Furthermore, the DC voltage converter module 4 - i can also include a transformer. In this case, the transformation ratio of the corresponding transformer can also be taken into account when regulating, in particular when generating the corresponding manipulated variable. For example, the transformation ratio of the transformer can be taken into account in the pilot control when generating the further manipulated variable R3.

[0045] Figure 3 A schematic diagram of a flow chart as a basis for a method for regulating a DC voltage converter 10 according to an embodiment is shown. The DC voltage converter 10 can in particular be the DC voltage converter 10 described above. The DC voltage converter 10 described above can also correspondingly perform all the method steps to be described below. The method described below can also similarly include all the steps described above in conjunction with the DC voltage converter 10.

[0046] In step S1, a first regulating variable R1 is generated. The first regulating variable R1 can be generated in particular using a setpoint value U_Soll for the output voltage U of the DC voltage converter 10 and a determined value U_In of the input voltage U of the DC voltage converter 10. In step S2, a plurality of unique second regulating variables R2-i can be generated. In particular, a separate second regulating variable R2-i can be generated for each DC voltage converter module 4-i. The second regulating variable R2-i can be influenced at the beginning of the charging process according to the first regulating variable R1, for example, by initialization of the current regulator 2-i. The corresponding second regulating variable R2-i can be generated using a determined value I_Ist-i for the current in the respectively assigned DC voltage converter module 4-i and a predetermined maximum current I_max-i for the corresponding DC voltage converter module 4-i. In step S3, the first regulating variable R1 for the respectively assigned DC voltage converter module 4-i and the corresponding second regulating variable R2-i can be combined. The combined manipulated variable can then be made available to the respective DC voltage converter module 4 - i.

[0047] In summary, the present invention relates to the regulation of a DC voltage converter having a plurality of DC voltage converter modules. To this end, a central regulation variable for voltage-controlled regulation of the DC voltage converter is generated for all DC voltage converter modules. In addition, a current-based regulation variable can be additionally generated for each DC voltage converter module. Through the combination of the voltage-based regulation variable and the current-based regulation variable, the output power, in particular the output current, of each DC voltage converter module can be uniquely adjusted. In this way, overloading of the DC voltage converter module can be avoided.

Claims

1. A regulating device (11) for a DC voltage converter (10) having a plurality of DC voltage converter modules (4-i), the regulating device comprising: A pilot control device (1) is designed to generate a first manipulated variable (R1) using a setpoint value (U_setpoint) for an output voltage of the DC voltage converter (10) and an ascertained value (U_In) for an input voltage of the DC voltage converter (10); A plurality of current regulators (2-i), wherein a current regulator (2-i) is respectively assigned to a DC voltage converter module (4-i), wherein the current regulators (2-i) are respectively designed to generate a unique second manipulated variable (R2-i) for the respectively assigned DC voltage converter module (4-i), and wherein the current regulators (2-i) are respectively designed to: determine the respective second manipulated variable (R2-i) using a determined value (I_Ist-i) for the current in the respectively assigned DC voltage converter module (4-i) and a predetermined maximum current (I_max-i) for the respective DC voltage converter module (4-i), in, The regulating device (11) has a voltage regulator (3) which is designed to generate a third manipulated variable (R3) using a setpoint value (U_setpoint) for the output voltage of the DC voltage converter (10) and an ascertained value (U_Ist) for the output voltage of the DC voltage converter (10). The voltage regulator (3) comprises a two-point regulator, which is designed to: output a third regulating variable (R3) at a first operating point, the third regulating variable being suitable for promoting the flow of current in the DC voltage converter module (4-i) when the value (U_Ist) of the output voltage of the DC voltage converter (10) is lower than a predetermined first threshold value; and output a third regulating variable (R3) at a second operating point, the third regulating variable being suitable for deactivating the flow of current in the DC voltage converter module (4-i) when the value (U_Ist) of the output voltage of the DC voltage converter (10) exceeds a predetermined second threshold value.

2. A regulating device (11) according to claim 1, wherein the multiple current regulators (2-i) are respectively designed to limit the output current (I_Ist-i) of the respectively assigned DC voltage converter module (4-i) to a predetermined maximum current (I_max-i).

3. A regulating device (11) according to claim 1 or 2, wherein the regulating device (11) is designed to deactivate the current regulator (2-i) when a predetermined output voltage (U_Ist) is reached at the output end of the DC voltage converter (10).

4. A DC voltage converter (10), comprising: A plurality of DC voltage converter modules (4-i), each of which is designed to convert an input DC voltage into an output DC voltage; and The regulating device (11) according to any one of claims 1 to 3, wherein a separate current regulator (2-i) is provided in the regulating device (11) for each DC voltage converter module (4-i) in the DC voltage converter (10).

5. The DC voltage converter (10) according to claim 4, wherein the DC voltage converter (10) is designed to be coupled to a capacitor (30) at the output. 6 . The DC voltage converter ( 10 ) as claimed in claim 5 , wherein the DC voltage converter ( 10 ) is designed to be coupled to an intermediate circuit capacitor at the output.

7. A method for regulating a DC voltage converter (10) according to any one of claims 4 to 6 having a plurality of DC voltage converter modules (4-i), the method comprising the following steps: generating (S1) a first manipulated variable (R1) using a setpoint value (U_setpoint) for an output voltage of the DC voltage converter (10) and an ascertained value (U_In) for an input voltage of the DC voltage converter (10); Generating (S2) a plurality of individual second controlled variables (R2-i) for a plurality of DC voltage converter modules (4-i), wherein each second controlled variable (R2-i) is generated using a determined value (I_Ist-i) for a current in a respectively associated DC voltage converter module (4-i) and a predetermined maximum current (I_max-i) for the corresponding DC voltage converter module (4-i); and A first manipulated variable (R1) and a second manipulated variable (R2-i) for the respectively associated DC voltage converter module (4-i) are combined (S3) and the respectively combined manipulated variable is made available at the corresponding DC voltage converter module (4-i).

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