Method and apparatus for controlling DC / DC converter of battery system, computer program product
By dividing the operating range in the DC/DC converter and selecting the corresponding phase current as the AC injection current, the complexity of the control algorithm caused by the switching of the conduction mode is solved, and the effects of simplifying control and reducing costs are achieved.
Patent Information
- Application Number
- CN202411290694.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-14
- Publication Date
- 2026-03-17
AI Technical Summary
In existing technologies, DC/DC converters are prone to switching of conduction modes during the generation of AC injection current, resulting in complex control algorithms and high technical overhead.
The operating range of the DC/DC converter is divided based on the collected battery system stack current, so that the DC/DC converter unit in each range operates in only one conduction mode, and the corresponding phase current is selected as the AC injection current to avoid conduction mode switching.
It effectively reduces the complexity of control algorithms and development costs of DC/DC converters, and simplifies control strategies.
Smart Images
Figure CN121689794A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of batteries, and more particularly to a method for controlling a DC / DC converter for a battery system, an apparatus for controlling a DC / DC converter for a battery system, and a computer program product for at least assisting in implementing the steps of the method according to this application. Background Technology
[0002] Fuel cells boast advantages such as high conversion efficiency, environmental friendliness, and simple and flexible assembly; however, reliability remains a significant factor limiting their large-scale application. Electrochemical impedance spectroscopy (EIS) is a crucial method for fault diagnosis in fuel cell systems. When measuring the EIS of a fuel cell stack, an AC injection current is provided via a DC / DC converter, and the stack voltage response is analyzed in the frequency domain. This allows the determination of the internal impedance of the fuel cell stack in the high-frequency domain. This internal impedance reflects the internal state of the fuel cell, including the water content of the proton exchange membrane, the liquid water content at the cathode, and the gas supply status.
[0003] To generate AC injection current, the DC / DC converter can operate in continuous conduction mode (CCM), discontinuous conduction mode (DCM), and / or critical conduction mode (BCM). Especially when the load current of the fuel cell changes, the DC / DC converter may switch between different conduction modes. This necessitates that the control algorithm of the DC / DC converter adapt to working collaboratively in different conduction modes and addressing various issues arising from conduction mode switching. Developing such a control algorithm is extremely complex and technically costly.
[0004] Therefore, how to avoid switching of the DC / DC converter's conduction mode as much as possible during the generation of AC injection current has become a technical challenge that needs to be solved. Summary of the Invention
[0005] The purpose of this application is to provide a method for controlling a DC / DC converter for a battery system, an apparatus for controlling a DC / DC converter for a battery system, and a computer program product for at least assisting in implementing the steps of the method according to this application, so as to solve the problems in the prior art.
[0006] According to a first aspect of this application, a method for controlling a DC / DC converter in a battery system is provided, the method comprising the following steps:
[0007] -Based on the collected data of the battery stack current I of the battery system SThe operating parameters of the DC / DC converter of the battery system are controlled to adjust the phase current of the DC / DC converter. The DC / DC converter includes a first DC / DC converter unit and a second DC / DC converter unit connected in parallel. This is done by adjusting the stack current I of the battery stack based on the acquired data. S The DC / DC converter is divided into at least three operating ranges, such that in each operating range, the first DC / DC converter unit and / or the second DC / DC converter unit each operate in only one conduction mode, wherein the conduction mode includes a continuous conduction mode and / or a discontinuous conduction mode; and
[0008] - Select the first phase current of the first DC / DC converter or the second phase current of the second DC / DC converter as the AC injection current of the battery system based on the conduction mode of the first DC / DC converter and / or the second DC / DC converter.
[0009] The core concept of this application lies in: based on the collected pile current I S The DC / DC converter is divided into at least three operating ranges, so that each DC / DC converter unit operates in only one conduction mode in each operating range. This is to avoid the DC / DC converter entering the prohibited operating region where conduction mode switching may occur. At the same time, the phase current of the DC / DC converter unit is selected as the AC injection current of the battery system based on the conduction mode of the DC / DC converter unit. This minimizes the conduction mode switching of the DC / DC converter unit used to provide the AC injection current, thereby effectively reducing the complexity and development cost of the DC / DC converter control algorithm.
[0010] According to a second aspect of this application, an apparatus for controlling a DC / DC converter in a battery system is provided, the apparatus being used to perform the method according to this application, wherein the apparatus includes the following components:
[0011] - Acquisition module, configured to acquire the stack current I of the battery stack in the battery system. S ;
[0012] - The converter control module is configured to measure the stack current I of the battery stack of the battery system based on the acquired data. S The operating parameters of the DC / DC converter of the battery system are controlled to adjust the phase current of the DC / DC converter. The DC / DC converter includes a first DC / DC converter unit and a second DC / DC converter unit connected in parallel. This is done by adjusting the stack current I of the battery stack based on the acquired data. SThe DC / DC converter is divided into at least three operating ranges, such that in each operating range, the first DC / DC converter unit and / or the second DC / DC converter unit each operate in only one conduction mode, wherein the conduction mode includes a continuous conduction mode and / or a discontinuous conduction mode; and
[0013] - Phase current selection module, which is configured to select phase current based on the first DC / DC converter unit and / or
[0014] Alternatively, the conduction mode of the second DC / DC converter unit may select either the first phase current of the first DC / DC converter unit or the second phase current of the second DC / DC converter unit as the AC injection current of the battery system.
[0015] According to a third aspect of this application, a computer program product, such as a computer-readable program carrier, is provided, comprising computer program instructions that, when executed by a processor, at least partially implement the steps of the method described in this application. Attached Figure Description
[0016] The principles, features, and advantages of this application will be better understood below with reference to the accompanying drawings. The drawings include:
[0017] Figure 1 A schematic block diagram of a battery system according to an exemplary embodiment of this application is shown;
[0018] Figure 2 A flowchart is shown of a method for controlling a DC / DC converter for a battery system according to an exemplary embodiment of this application;
[0019] Figure 3 A schematic diagram of a Boost topology of a DC / DC converter according to an exemplary embodiment of this application is shown.
[0020] Figure 4 A schematic diagram of a Buck topology of a DC / DC converter according to an exemplary embodiment of this application is shown;
[0021] Figure 5 A schematic diagram of the operating range of the phase current of a DC / DC converter with a Boost topology according to an exemplary embodiment of this application is shown.
[0022] Figure 6 A schematic diagram of the operating range of the phase current of a DC / DC converter with a Buck topology according to another exemplary embodiment of this application is shown;
[0023] Figure 7A schematic diagram of the operating range of the phase current of a DC / DC converter with a Boost topology according to another exemplary embodiment of this application is shown; and
[0024] Figure 8 A schematic block diagram of an apparatus for controlling a DC / DC converter for a battery system according to an exemplary embodiment of this application is shown. Detailed Implementation
[0025] To make the technical problems to be solved, the technical solutions, and the beneficial technical effects of this application clearer, the application will be further described in detail below with reference to the accompanying drawings and several exemplary embodiments. It should be understood that the specific embodiments described herein are only for explaining this application and are not intended to limit the scope of protection of this application.
[0026] Figure 1 A schematic block diagram of a battery system 100 according to an exemplary embodiment of this application is shown. The battery system 100 may be, in particular, a fuel cell system, or other types of battery systems such as lithium-ion batteries. The output voltage of the battery stack 2 (i.e., the stack voltage U) is... S It is converted into a high-voltage DC voltage U through DC / DC converter 3. H It is then supplied to the high-voltage power supply network of the electric vehicle. Device 1 is connected to the input side of DC / DC converter 3 and configured to control the DC / DC converter 3 of the battery system 100. Here, the stack current I of the battery stack 2 can be acquired via the acquisition module 11 of device 1. S Optionally, the stack voltage U of battery stack 2 can also be collected. S High-voltage DC voltage U of the high-voltage power supply network for electric vehicles and / or electric vehicles H wait.
[0027] Figure 2 A flowchart illustrating a method for controlling a DC / DC converter for a battery system according to an exemplary embodiment of this application is shown. The following exemplary embodiments describe the method according to this application in more detail.
[0028] like Figure 2 As shown, the method may include steps S1 and S2. In step S1, based on the collected stack current I of the battery stack 2 of the battery system 100... S The operating parameters of the DC / DC converter 3 of the battery system 100 are controlled to adjust the phase current of the DC / DC converter 3. The DC / DC converter 3 includes a first DC / DC converter unit 31 and a second DC / DC converter unit 32 connected in parallel. The method is based on the collected stack current I of the battery stack 2. SThe DC / DC converter 3 is divided into at least three operating ranges, such that in each operating range, the first DC / DC converter unit 31 and / or the second DC / DC converter unit 32 operate in only one conduction mode.
[0029] In the current embodiment of this application, the first DC / DC conversion unit 31 and the second DC / DC conversion unit 32 may be configured, for example, as a Boost topology, a Buck topology, or a Buck-Boost topology. Figure 3 A schematic diagram of a Boost topology of a DC / DC converter 3 according to an exemplary embodiment of this application is shown, which includes an inductor L, a first filter capacitor C1, a second filter capacitor C2, a first semiconductor transistor T1, a second semiconductor transistor T2, a third semiconductor transistor T3, and a fourth semiconductor transistor T4, etc., wherein these semiconductor transistors may be configured as, for example, thyristors SCR, field-effect transistors MOSFET, or insulated-gate bipolar transistors IGBT, etc. Figure 4 A schematic diagram of a Buck topology of a DC / DC converter 3 according to an exemplary embodiment of this application is shown, which includes an inductor L, a first filter capacitor C1, a second filter capacitor C2, a first semiconductor transistor T1, a rectifier diode B2, and a fourth semiconductor transistor T4, etc.
[0030] The driver circuit of the DC / DC converter 3 can control the turn-on / turn-off time of each semiconductor transistor according to the PWM voltage waveform applied to each semiconductor transistor, thereby forming different conduction modes of the DC / DC converter 3. The conduction modes may include continuous conduction mode and / or discontinuous conduction mode, etc.
[0031] The load current of battery system 100 is relatively large—this means the stack current I... S In cases where the voltage is relatively high, the PWM voltage waveforms controlling each semiconductor transistor are typically complementary, thus providing a continuous conductive path between the input voltage source and ground. During one switching cycle, the current flowing through the inductor of DC / DC converter 3 is always greater than zero. This conduction mode of DC / DC converter 3 is called continuous conduction mode (CCM). For example, in the continuous conduction mode of DC / DC converter 3 with a Buck topology, the average current flowing through the inductor of DC / DC converter 3 can be calculated using the following formula 1:
[0032]
[0033] Where D represents the duty cycle of the switching signal of DC / DC converter 3, T represents the period of the PWM signal, and U SU represents the input voltage of DC / DC converter 3 (i.e., the stack voltage of battery stack 2). H L represents the output voltage of DC / DC converter 3 (i.e., the high-voltage DC voltage supplied to the high-voltage power supply network of the electric vehicle), and I represents the inductance value of DC / DC converter 3. offset This indicates the offset current caused by the bias current of the semiconductor transistor and / or rectifier diode.
[0034] The load current of battery system 100 is relatively small—this means the stack current I... S In smaller cases, the PWM voltage waveform controlling each semiconductor transistor is typically a switching signal with a relatively narrow pulse width, resulting in a very short, constant on-time for each transistor. This causes the current flowing through the inductor of DC / DC converter 3 to be intermittent within a switching cycle, sometimes equal to zero and sometimes greater than zero. This conduction mode of DC / DC converter 3 is called discontinuous conduction mode (DCM). For example, in the discontinuous conduction mode of DC / DC converter 3 with a Buck topology, the average current flowing through the inductor of DC / DC converter 3 can be calculated using the following formula 2:
[0035]
[0036] In existing DC / DC converter control strategies, the phase current of one DC / DC converter unit is typically selected as the AC injection current of the battery system 100, and the electrochemical impedance spectrum of the battery stack 2 can be calculated using this AC injection current. However, the conduction mode in which either the first DC / DC converter unit 31 or the second DC / DC converter unit 32 operates depends on the stack current I of the battery stack 2. S Especially when the load on the battery system 100 changes, the stack current I S The phase current and pile current I of the DC / DC converter unit will also change. S There are corresponding mathematical relationships under different topologies of DC / DC converter units (including Boost topology, Buck topology, and Buck-Boost topology), for varying stack current I. S The duty cycle of the signal switching of the DC / DC converter unit needs to be adjusted so that the phase current of the DC / DC converter unit satisfies the condition of the pile current I. S The corresponding mathematical relationship, and the change of the duty cycle of the signal switch may cause the DC / DC converter unit to switch the conduction mode. This conduction mode switching requires the control algorithm of the DC / DC converter to adapt to working together in different conduction modes and to deal with various technical problems caused by conduction mode switching. The development of such control algorithm is extremely complex and has high technical overhead.
[0037] In the configuration scheme of this application, the stack current I of the battery stack 2 can be collected. S The DC / DC converter 3 is divided into at least three operating ranges, such that in each operating range, the first DC / DC converter unit 31 and / or the second DC / DC converter unit 32 operate in only one conduction mode, that is, the conduction mode of each DC / DC converter unit does not switch in each operating range.
[0038] Figure 5 A schematic diagram of the operating range of the phase current of a DC / DC converter with a Boost topology according to an exemplary embodiment of this application is shown. Figure 6 A schematic diagram illustrating the operating range of the phase current of a DC / DC converter with a Buck topology according to an exemplary embodiment of this application is shown. Considering that a DC / DC converter with a Buck-Boost topology can select between Boost mode and Buck mode based on the magnitude of the input and output voltages, the Buck-Boost topology in either Boost or Buck mode will not be described again here. Figure 5 and Figure 6 As shown, based on the collected stack current I of battery stack 2 S The operating range of DC / DC converter 3 can be divided into the first operating range W1, the second operating range W2, and the third operating range W3.
[0039] In the pile current I S When the current value is less than or equal to the first preset current value I1 (e.g., 15A), the DC / DC converter 3 operates in the first operating range W1. In the first operating range W1, the duty cycle D1 of the first switching signal of the first DC / DC converter unit 31 is controlled so that the first DC / DC converter unit 31 always operates only in the discontinuous conduction mode, while the second DC / DC converter unit 32 is always in the off state.
[0040] When the first DC / DC converter unit 31 is configured as a Boost topology, the duty cycle D1 of the first switching signals of the first semiconductor switch T1 and the third semiconductor switch T3 of the first DC / DC converter unit 31 is controlled so that, in the first operating interval W1, the first phase current I of the first DC / DC converter unit 31 is... P1 Equal to the pile current I S .like Figure 5 As shown, the first operating range W1 is the first phase current I. P1 The second phase current I is in the range of 0 to I1. P2The operating region that is always equal to zero.
[0041] When the first DC / DC converter unit 31 is configured in a Buck topology, the duty cycle D1 of the first switching signal of the first semiconductor switch T1 of the first DC / DC converter unit 31 is controlled so that, in the first operating range, the first phase current I of the first DC / DC converter unit 31 is... P1 Equal to the pile current I S The product of the first switch signal duty cycle D1 and I S D1. For example... Figure 6 As shown, the first operating range W1 is the first phase current I. P1 The second phase current I is in the range of 0 to I1D1. P2 The operating region that is always equal to zero.
[0042] In the pile current I S When the current is greater than the first preset current value I1 and less than the second preset current value I2 (e.g., 150A), the DC / DC converter 3 operates in the second operating range W2. In the second operating range W2, the duty cycle D1 of the first switching signal of the first DC / DC converter 31 and the duty cycle D2 of the second switching signal of the second DC / DC converter 32 are controlled so that the first DC / DC converter 31 operates only in the discontinuous conduction mode and the second DC / DC converter 32 operates only in the continuous conduction mode.
[0043] When the DC / DC converter 3 is configured in a Boost topology, the duty cycle D1 of the first switching signal of the first semiconductor switch T1 and the third semiconductor switch T3 of the first DC / DC converter unit 31 and the duty cycle D2 of the second switching signal of the first semiconductor switch T1 and the third semiconductor switch T3 of the second DC / DC converter unit 32 are controlled so that, in the second operating interval W2, the first phase current I of the first DC / DC converter unit 31 is... P1 The second phase current I of the second DC / DC converter unit 32 remains equal to the first preset current value I1. P2 Equal to the pile current I S With the first phase current I P1 Difference I S -I P1 .like Figure 5 As shown, the second operating interval W2 is the first phase current I. P1 Always equal to I1 and the second phase current I P2 The operating range is between 0 and I2-I1.
[0044] When the first DC / DC converter 31 is configured in a Buck topology, the duty cycle D1 of the first switching signal of the first semiconductor switch T1 of the first DC / DC converter 31 and the duty cycle D2 of the second switching signal of the first semiconductor switch T1 of the second DC / DC converter 32 are controlled so that, in the second operating interval W2, the first phase current I of the first DC / DC converter 31 is... P1 It is equal to the product of the first preset current value I1 and the duty cycle D1 of the first signal switch, I1D1, and the second phase current I P2 Equal to the pile current I S The product of the second signal switch duty cycle D2 and the first phase current I P1 The difference I between the product of the second signal switch duty cycle D2 and the ratio of the first signal switch duty cycle D1 and the second signal switch duty cycle D2 is... S D2-I P1 D2 / D1. For example... Figure 6 As shown, the second operating interval W2 is the first phase current I. P1 Always equal to I1D1 and the second phase current I P2 The operating region is located in the interval from 0 to I2D2-I1D1.
[0045] In the pile current I S When the current value is greater than or equal to the second preset current value I2 and less than or equal to the third preset current value I3 (e.g., 600A), the DC / DC converter 3 can operate in the third operating range W3. In the third operating range W3, the duty cycle D1 of the first switching signal of the first DC / DC converter 31 and the duty cycle D2 of the second switching signal of the second DC / DC converter 32 are controlled so that the first DC / DC converter 31 and the second DC / DC converter 32 operate only in continuous conduction mode.
[0046] When the DC / DC converter 3 is configured in a Boost topology, the duty cycle D1 of the first switching signal of the first semiconductor switch T1 and the third semiconductor switch T3 of the first DC / DC converter unit 31 and the duty cycle D2 of the second switching signal of the first semiconductor switch T1 and the third semiconductor switch T3 of the second DC / DC converter unit 32 are controlled so that, in the third operating interval W3, the first phase current I of the first DC / DC converter unit 31 is... P1 and the second phase current I of the second DC / DC converter unit 32 P2 All are equal to the pile current I S Half of Is / 2. (e.g.) Figure 5 As shown, the third operating interval W3 is the first phase current I. P1 It is in the range of I2 / 2 to I3 / 2 and the second phase current IP2 The operating range is between I2 / 2 and I3 / 2.
[0047] When the DC / DC converter 3 is configured in a Buck topology, the duty cycle D1 of the first switching signal of the first semiconductor switch T1 of the first DC / DC converter unit 31 and the duty cycle D2 of the second switching signal of the first semiconductor switch T1 of the second DC / DC converter unit 32 are controlled so that, in the third operating interval W3, the first phase current I of the first DC / DC converter unit 31 is... P1 Equal to the pile current I S The product of half of the first signal switch duty cycle D1 and I P1 D1 / 2, and the second phase current I of the second DC / DC converter unit 32 P2 Equal to the pile current I S The product of half of the second signal switch duty cycle D2 and I S D2 / 2. For example... Figure 6 As shown, the third operating interval W3 is the first phase current I. P1 It is located in the range of I2D1 / 2 to I3D1 / 2 and the second phase current I P2 The operating range is between I2D2 / 2 and I3D2 / 2.
[0048] like Figure 5 and Figure 6 As shown, the process of switching from the second operating region W2 to the third operating region W3 can be represented by the operation indicated by the dashed arrow, as the stack current I... S Increased to more than I2, the first phase current I P1 Second phase current I P2 All current values undergo sudden changes, indicated by dashed arrows. This allows DC / DC converter 3 to bypass the prohibited operating region V enclosed by dotted lines, where each DC / DC converter unit may experience changes in current value due to stack current I. S The switching of conduction modes occurs due to changes in the conduction mode. This switching requires the control algorithm of the DC / DC converter to adapt to working together in different conduction modes and to cope with various technical problems caused by the switching of conduction modes. The development of such a control algorithm is extremely complex and has a high technical cost. By dividing the operating region according to the method of this application, the DC / DC converter 3 is effectively prevented from operating into the prohibited operating region V, thereby simplifying the control algorithm of the DC / DC converter.
[0049] In the first operating interval W1, the first DC / DC converter 31 operates only in discontinuous conduction mode, and the second DC / DC converter 32 is in a disabled state. In the second operating interval W2, the first DC / DC converter 31 operates only in discontinuous conduction mode, and the second DC / DC converter 32 operates only in continuous conduction mode. This means that when the stack current I... S When the value changes at the critical value I1 of these two operating ranges, it will cause frequent switching of the conduction modes of the first DC / DC converter unit 31 and the second DC / DC converter unit 32. In order to avoid frequent switching of the conduction modes of each DC / DC converter unit in the first operating range W1 and the second operating range W2, a hysteresis region can be introduced at the critical value of these two operating ranges.
[0050] like Figure 7 The diagram shown illustrates the operating range of the phase current of a DC / DC converter with a Boost topology according to another exemplary embodiment of this application, wherein the hysteresis region is the first phase current I. P1 Located in the interval from I1-H2 to I1+H1 and the second phase current I P2 The operating region is within the range of 0 to I2-I1. When the stack current I... S When the stack current I increases, S When the sum of the first preset current value I1 and the first hysteresis threshold H1, I1+H1, is less than or equal to the sum of the first preset current value I1 and the first hysteresis threshold H1, the DC / DC converter 3 operates in the first operating range W1. In the first operating range W1, the duty cycle D1 of the first switching signal of the first DC / DC converter unit 31 is controlled so that the first DC / DC converter unit 31 operates only in the discontinuous conduction mode, and the second DC / DC converter unit 32 is in a deactivated state.
[0051] When the stack current I S When the current I decreases, S When the current is greater than the difference between the first preset current value I1 and the second hysteresis threshold H2 (I1-H2) and less than the second preset current value I2, the DC / DC converter 3 operates in the second operating range W2. In the second operating range W2, the duty cycle D1 of the first switching signal of the first DC / DC converter 31 and the duty cycle D2 of the second switching signal of the second DC / DC converter 32 are controlled so that the first DC / DC converter 31 operates only in the discontinuous conduction mode and the second DC / DC converter 32 operates only in the continuous conduction mode.
[0052] In step S2, the first phase current of the first DC / DC converter 31 or the second phase current of the second DC / DC converter 32 is selected as the AC injection current of the battery system 100 based on the conduction mode of the first DC / DC converter 31 and / or the second DC / DC converter 32. In the first operating interval W1 and / or the second operating interval W2, the first phase current I of the first DC / DC converter 31 operating in discontinuous conduction mode can be selected. P1 As the AC injection current of the battery system 100, this ensures that the first DC / DC converter unit used to provide the AC injection current never switches its conduction mode in either of the two operating intervals. In the third operating interval W3, the first phase current I of the first DC / DC converter unit 31, which can be selected to operate in continuous conduction mode, can be... P1 Or the second phase current I of the second DC / DC converter unit 32 operating in continuous conduction mode P2 The AC injection current of the battery system 100 is provided by any fixed DC / DC converter unit. The electrochemical impedance spectroscopy of the battery stack 2 can be calculated using the AC injection current.
[0053] It should be noted that in the above embodiments, the first DC / DC conversion unit 31 and the second DC / DC conversion unit 32 can be interchanged, and will not be described again here.
[0054] According to an embodiment of this application, based on the collected pile current I S The DC / DC converter is divided into at least three operating ranges, so that each DC / DC converter unit operates in only one conduction mode in each operating range. This is to avoid the DC / DC converter entering the prohibited operating region where conduction mode switching may occur. At the same time, the phase current of the DC / DC converter unit is selected as the AC injection current of the battery system based on the conduction mode of the DC / DC converter unit. This minimizes the conduction mode switching of the DC / DC converter unit used to provide the AC injection current, thereby effectively reducing the complexity and development cost of the DC / DC converter control algorithm.
[0055] In addition, it should be noted that the step numbers described herein do not necessarily represent the order of steps, but are merely a reference numeral. The order may be changed depending on the specific circumstances, as long as the technical objective of this application can be achieved.
[0056] Figure 8 A schematic block diagram of a device 1 for controlling a DC / DC converter of a battery system according to an exemplary embodiment of the present application is shown.
[0057] like Figure 8As shown, the device 1 may include the following components:
[0058] - Acquisition module 11, which is configured to acquire the stack current I of the battery stack 2 of the battery system 100. S Optionally, the stack voltage U of battery stack 2 can also be collected. S High-voltage DC voltage U of the high-voltage power supply network for electric vehicles and / or electric vehicles H The acquisition module 11 includes, for example, a current sensor, and optionally also includes a voltage sensor.
[0059] - Converter control module 12, which is configured to use the stack current I of the battery stack 2 of the battery system 100 as a basis for measurement. S The operating parameters of the DC / DC converter 3 of the battery system 100 are controlled to adjust the phase current of the DC / DC converter 3. The DC / DC converter 3 includes a first DC / DC converter unit 31 and a second DC / DC converter unit 32 connected in parallel. The method is based on the collected stack current I of the battery stack 2. S The DC / DC converter 3 is divided into at least three operating ranges, such that in each operating range, the first DC / DC converter unit 31 and / or the second DC / DC converter unit 32 each operate in only one conduction mode, wherein the conduction mode includes a continuous conduction mode and / or a discontinuous conduction mode; and
[0060] A phase current selection module 13 is configured to select the first phase current of the first DC / DC converter 31 or the second phase current of the second DC / DC converter 32 as the AC injection current of the battery system 100 based on the conduction mode of the first DC / DC converter 31 and / or the second DC / DC converter 32.
[0061] It should be understood that the terms “first,” “second,” “third,” etc., used in this document are for descriptive purposes only and should not be construed as indicating or implying relative importance, nor should they be construed as implicitly specifying the number of technical features indicated.
[0062] If an embodiment includes an "and / or" association between a first feature and a second feature, it should be interpreted as follows: according to one implementation, the embodiment has not only the first feature but also the second feature; according to another implementation, the embodiment has either only the first feature or only the second feature.
[0063] Although specific embodiments have been described above, these embodiments are not intended to limit the scope of this application, even when only a single embodiment is described with respect to a particular feature. The feature examples provided in this application are intended for illustrative purposes and not for limitation, unless otherwise stated. In practice, multiple features may be combined with each other as needed and where technically feasible. Various substitutions, modifications, and alterations are also conceived without departing from the spirit and scope of this application.
Claims
1. A method for controlling a DC / DC converter (3) of a battery system (100), the method comprising the steps of: based on the acquired stack current I of the battery stack (2) of the battery system (100) S controlling an operating parameter of a DC / DC converter (3) of the battery system (100) to regulate a phase current of the DC / DC converter (3), the DC / DC converter (3) comprising a first DC / DC conversion unit (31) and a second DC / DC conversion unit (32) connected in parallel, in such a way that, based on the acquired stack current I of the battery stack (2) S dividing at least three operating intervals of the DC / DC converter (3) in such a way that, in each operating interval, the first DC / DC conversion unit (31) and / or the second DC / DC conversion unit (32) is / are respectively only operated in one conduction mode, wherein the conduction mode comprises a continuous conduction mode and / or a discontinuous conduction mode; selecting a first phase current of the first DC / DC conversion unit (31) or a second phase current of the second DC / DC conversion unit (32) as an AC injection current of the battery system (100) based on a conduction mode of the first DC / DC conversion unit (31) and / or the second DC / DC conversion unit (32).
2. The method of claim 1, wherein, at the stack current I S If the current is less than or equal to the first preset current value I1, the DC / DC converter (3) operates in a first operating interval, in which the first DC / DC conversion unit (31) is controlled by the first switching signal duty ratio D1 so that the first DC / DC conversion unit (31) only operates in a discontinuous conduction mode, and the second DC / DC conversion unit (32) is in a deactivated state.
3. The method of claim 2, wherein, at the stack current I S In the case that the stack current I is greater than the first preset current value I1 and less than the second preset current value I2, the DC / DC converter (3) operates in a second operating interval, in which the first DC / DC conversion unit (31) is controlled to operate only in a discontinuous conduction mode and the second DC / DC conversion unit (32) is controlled to operate only in a continuous conduction mode.
4. The method of claim 1, wherein, at the stack current I S at the stack current I S If the stack current I is less than or equal to the sum of the first preset current value I1 and the first hysteresis threshold value H1 (I1+H1), the DC / DC converter (3) operates in a first operating interval, in which the first DC / DC conversion unit (31) is controlled by the first switching signal duty ratio D1 so that the first DC / DC conversion unit (31) operates only in the discontinuous conduction mode, and the second DC / DC conversion unit (32) is in the inactive state.
5. The method of claim 4, wherein, at the stack current I S decreases and at the stack current I S In the case that the first preset current value I1 is greater than the second preset current value I2, the DC / DC converter (3) operates in a third operating interval, in which the first DC / DC conversion unit (31) and the second DC / DC conversion unit (32) are controlled to operate in the discontinuous conduction mode and the continuous conduction mode, respectively.
6. The method of any one of claims 2 to 5, wherein, In the first operating interval and / or in the second operating interval, a first phase current I of a first DC / DC conversion unit (31) selected to operate in a discontinuous conduction mode is selected P1 as the AC injection current of the battery system (100).
7. The method of any one of claims 2 to 5, wherein, at the stack current I S In the case that the stack current I is greater than or equal to the second preset current value I2 and less than or equal to the third preset current value I3, the DC / DC converter (3) operates in a third operating interval, in which the first switching signal duty cycle D1 of the first DC / DC conversion unit (31) and the second switching signal duty cycle D2 of the second DC / DC conversion unit (32) are controlled so that the first DC / DC conversion unit (31) and the second DC / DC conversion unit (32) operate only in the continuous conduction mode, respectively.
8. The method of claim 7, wherein, In the third operating interval, a first phase current I of the first DC / DC conversion unit (31) is selected, which is operated in continuous conduction mode P1 or a second phase current I of the second DC / DC conversion unit (32) is selected, which is operated in continuous conduction mode P2 as the AC injection current of the battery system (100).
9. An apparatus (1) for controlling a DC / DC converter (3) of a battery system (100), the apparatus (1) being configured to perform the method according to any one of claims 1 to 8, wherein, The apparatus (1) comprises the following means: a collection module (11) configured to collect a stack current I of a battery stack (2) of the battery system (100) S ; a converter control module (12) configured to control an operating parameter of a DC / DC converter (3) of the battery system (100) based on the acquired stack current I of the battery stack (2) of the battery system (100) in order to regulate a phase current of the DC / DC converter (3), the DC / DC converter (3) comprising a first DC / DC conversion unit (31) and a second DC / DC conversion unit (32) connected in parallel, in such a way that the operating parameter of the DC / DC converter (3) is controlled based on the acquired stack current I of the battery stack (2) of the battery system (100) in order to regulate a phase current of the DC / DC converter (3), the DC / DC converter (3) comprising a first DC / DC conversion unit (31) and a second DC / DC conversion unit (32) connected in parallel, S an operating parameter of a DC / DC converter (3) of the battery system (100) in order to regulate a phase current of the DC / DC converter (3), the DC / DC converter (3) comprising a first DC / DC conversion unit (31) and a second DC / DC conversion unit (32) connected in parallel, in such a way that the operating parameter of the DC / DC converter (3) is controlled based on the acquired stack current I of the battery stack (2) of the battery system (100) in order to regulate a phase current of the DC / DC converter (3), the DC / DC converter (3) comprising a first DC / DC conversion unit (31) and a second DC / DC conversion unit (32) connected in parallel, S dividing at least three operating intervals of the DC / DC converter (3) in such a way that in each operating interval the first DC / DC conversion unit (31) and / or the second DC / DC conversion unit (32) is / are operated only in one conduction mode, respectively, wherein the conduction mode comprises a continuous conduction mode and / or a discontinuous conduction mode; and a phase current selection module (13) configured for selecting a first phase current of the first DC / DC conversion unit (31) or a second phase current of the second DC / DC conversion unit (32) as an AC injection current of the battery system (100) based on a conduction mode of the first DC / DC conversion unit (31) and / or the second DC / DC conversion unit (32).
10. A computer program product, e.g. a computer readable program carrier, containing computer program instructions at least indirectly implementing the steps of the method according to any one of the preceding claims 1 to 8 when the computer program instructions are executed by a processor.