Harmonic injection method, voltage conversion circuit, and storage medium
By establishing a complex frequency domain equivalent circuit model in the voltage conversion circuit and determining the expression for the input capacitor value, harmonic injection was achieved, solving the problem of excessively high peak resonant inductor current, reducing costs, and improving stability and convenience.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- SHENZHEN POWEROAK NEWENER CO LTD
- Filing Date
- 2026-02-04
- Publication Date
- 2026-07-21
Smart Images
Figure CN121643500B_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of power electronics technology, and in particular to a harmonic injection method, a voltage conversion circuit, and a storage medium. Background Technology
[0002] In the field of power electronics technology, voltage conversion circuits are widely used in various scenarios such as new energy power generation, electric transmission, and energy storage systems.
[0003] Excessively high peak current in the resonant inductor of a voltage converter circuit not only significantly exacerbates switching current stress but also induces radiated interference. Harmonic injection into the voltage converter circuit can reduce the peak current of the resonant inductor, thereby reducing its conduction losses and thermal stress, and effectively reduce radiated interference. Related technologies require hardware multi-resonant structures combined with software multi-harmonic control algorithms to perform harmonic injection. However, this increases hardware costs due to the multi-resonant structure, and the multiple control variables can increase computational complexity and reduce the stability of harmonic injection. Summary of the Invention
[0004] Based on this, this application provides a voltage conversion circuit and a method for determining its capacitance expression, as well as a storage medium, which can reduce the cost of harmonic injection and improve the convenience and stability of harmonic injection.
[0005] In a first aspect, this application provides a harmonic injection method, wherein the voltage conversion circuit includes a voltage input terminal, a filter circuit, and a series resonant conversion circuit; the input terminal of the filter circuit is connected to the voltage input terminal, and the output terminal of the filter circuit is connected to the series resonant conversion circuit, which includes a transformer, a resonant inductor, and a resonant capacitor; the method includes:
[0006] The current-voltage loop equations established based on the complex frequency domain equivalent circuit model of the voltage transformation circuit are used to determine the complex frequency domain transient current expression of the resonant inductor in the half-wave time domain.
[0007] Based on the complex frequency domain transient current expression, the time domain current expression of the resonant inductor containing the fundamental angular frequency and harmonic angular frequency values is obtained. The fundamental angular frequency value is the angular frequency value when the voltage conversion circuit resonates. The harmonic angular frequency value is an odd multiple of the fundamental angular frequency value. Both the fundamental angular frequency value and the harmonic angular frequency value are related to the component parameters of the filter circuit and the series resonant conversion circuit. The harmonic angular frequency value is the angular frequency value of the harmonic component injected into the voltage conversion circuit.
[0008] When the harmonic angular frequency is a fundamental angular frequency that is a multiple of the target, determine the expression for the capacitance value of the input capacitor in the filter circuit. The expression for the capacitance value represents the relationship between the capacitance value of the input capacitor, the target multiple, the inductance value of the lead inductance at the voltage input terminal of the filter circuit, the amplification factor of the transformer, the inductance value of the resonant inductor, and the capacitance value of the resonant capacitor.
[0009] In some embodiments, based on the complex frequency domain transient current expression, the time-domain current expression of the resonant inductor, including the fundamental angular frequency and harmonic angular frequency values, is obtained, including:
[0010] By partially decomposing the expression for transient current in the complex frequency domain, the complex frequency domain decomposition of the resonant inductor with respect to the fundamental and harmonic angular frequencies is obtained.
[0011] By performing an inverse Laplace transform on the complex frequency domain decomposition, the time-domain current expression of the resonant inductor is obtained.
[0012] In some embodiments, the time-domain current expression of the resonant inductor is:
[0013] ;
[0014] in, Represents resonant inductance The time-domain current value; Indicates the fundamental angular frequency value; A represents the harmonic angular frequency value; B represents the amplitude of the fundamental component on the cosine wave; C represents the amplitude of the harmonic component on the cosine wave; D represents the amplitude of the harmonic component on the sine wave.
[0015] ; ;
[0016] ; ;
[0017] ; ;
[0018] ; ;
[0019] This indicates the capacitance value of the resonant capacitor; Indicates the inductance value of the lead wire; Indicates the amplification factor of the transformer; This indicates the capacitance value of the input capacitor; This indicates the inductance value of the resonant inductor; This indicates the initial current value of the lead inductance; This represents the equivalent quality factor of the series resonant converter circuit. This indicates the input voltage value at the voltage input terminal; This represents the output power value of the series resonant converter circuit.
[0020] In some embodiments, when the harmonic angular frequency is a fundamental angular frequency value that is a multiple of the target value, determining the capacitance expression of the input capacitor in the filter circuit includes:
[0021] based on , , as well as The capacitance expression is determined as follows:
[0022] ;
[0023] in, Indicates the target multiple; This indicates the capacitance value of the resonant capacitor; Indicates the inductance value of the lead wire; Indicates the amplification factor of the transformer; This indicates the capacitance value of the input capacitor; This represents the inductance value of the resonant inductor.
[0024] In some embodiments, the current-voltage loop equation established based on the complex frequency domain equivalent circuit model of the voltage transformation circuit determines the complex frequency domain transient current expression of the resonant inductor in the half-wave time domain, including:
[0025] Based on the equivalent circuit model of the voltage transformation circuit in the complex frequency domain and Kirchhoff's laws, the voltage equation of the first complex frequency domain loop on the primary side of the transformer, the voltage equation of the second complex frequency domain loop on the secondary side of the transformer, and the current loop equation in the complex frequency domain are determined.
[0026] Based on the first complex frequency domain loop voltage equation, the second complex frequency domain loop voltage equation, and the complex frequency domain current loop equation, the complex frequency domain transient current expression of the resonant inductor in the half-wave time domain is determined.
[0027] Among them, the first complex frequency domain loop voltage equation is the complex frequency domain voltage loop equation of the primary side of the transformer, the second complex frequency domain loop voltage is the complex frequency domain voltage loop equation of the secondary side of the transformer, and the complex frequency domain current loop equation is the current shunt equation of the lead inductance at the input terminal of the voltage conversion circuit.
[0028] In some embodiments, the expression for the voltage equation of the first complex frequency domain loop is:
[0029] ;
[0030] in, This indicates the input voltage value at the voltage input terminal; Indicates the amplification factor of the transformer; Represents complex frequency; Indicates the inductance value of the lead wire; This represents the complex frequency domain current value of the lead inductance; This indicates the initial current value of the lead inductance; This indicates the capacitance value of the input capacitor; This represents the complex frequency domain current value of the input capacitor.
[0031] In some embodiments, the expression for the second complex frequency domain loop voltage equation is:
[0032] ;
[0033] in, Indicates the amplification factor of the transformer; Represents complex frequency; This indicates the capacitance value of the input capacitor; This represents the complex frequency domain current value of the input capacitor; This indicates the input voltage value at the voltage input terminal; This represents the complex frequency domain current value of the resonant inductor; This indicates the inductance value of the resonant inductor; This indicates the capacitance value of the resonant capacitor; It represents the equivalent quality factor of a series resonant converter circuit.
[0034] In some embodiments, the expression for the complex frequency domain current loop equation is:
[0035] ;
[0036] in, This represents the complex frequency domain current value of the lead inductance; This represents the complex frequency domain current value of the input capacitor; This represents the complex frequency domain current value of the resonant inductor.
[0037] Secondly, this application provides a voltage conversion circuit, which includes a voltage input terminal, a filter circuit, and a series resonant conversion circuit; the input terminal of the filter circuit is connected to the voltage input terminal, and the output terminal of the filter circuit is connected to the series resonant conversion circuit.
[0038] The capacitance value of the input capacitor in the filter circuit is determined according to the capacitance value expression, which is determined according to the harmonic injection method of any one of the first aspects.
[0039] Thirdly, this application provides a computer storage medium in which a computer program, when executed by a processor, implements the steps of any one of the methods in the first aspect.
[0040] In the technical solution provided in this application embodiment, by establishing the current-voltage loop equation of the voltage conversion circuit in the complex frequency domain, the expression of the transient current in the complex frequency domain of the resonant inductor in the half-wave time domain is derived, thereby obtaining the fundamental angular frequency value and the harmonic angular frequency value. Then, combined with the fundamental angular frequency value whose harmonic angular frequency value is a multiple of the target fundamental angular frequency value, the capacitance expression of the input capacitor in the filter circuit is determined. In the determined series resonant conversion circuit, when the target multiple of the fundamental harmonic to be injected is determined, the angular frequency value of the injected harmonic can be obtained through the input capacitor at the input end of the determined series resonant conversion circuit, thereby realizing the injection of the target multiple of the harmonic in the voltage conversion circuit. Thus, the harmonic injection method of this application is portable, meaning it can be applied to series resonant converter circuits with different circuit parameters. Furthermore, it avoids adding a hardware multi-resonant structure to the voltage conversion circuit, thereby reducing the cost of harmonic injection. It also eliminates the need to determine the electrical parameters of the multi-resonant structure and design complex multi-harmonic control algorithms, thus avoiding increased computational complexity due to multiple control quantities. Therefore, it significantly simplifies the method of injecting harmonic components into the voltage conversion circuit and reduces the instability caused by inaccurate determination of the electrical parameters of the multi-resonant structure or limited accuracy of the multi-harmonic control algorithm, thereby improving the convenience and stability of harmonic injection. Attached Figure Description
[0041] To more clearly illustrate the technical solutions in the embodiments of this application or related technologies, the drawings used in the description of the embodiments of this application or related technologies will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.
[0042] Figure 1 A hardware block diagram of the voltage conversion circuit provided in the embodiments of this application;
[0043] Figure 2 This is a circuit diagram of the voltage conversion circuit according to an embodiment of this application;
[0044] Figure 3 A schematic flowchart of the harmonic injection method provided in the embodiments of this application;
[0045] Figure 4 This is a schematic diagram of the complex frequency domain equivalent circuit model of the voltage conversion circuit provided in the embodiments of this application;
[0046] Figure 5 A schematic flowchart of the harmonic injection method provided in the embodiments of this application;
[0047] Figure 6 For some embodiments, the switching transistor under different harmonic injection conditions and A schematic diagram showing the changes in voltage across a series circuit and current in a resonant inductor over time.
[0048] Figure 7 A schematic diagram of the structure of the electronic device provided in the embodiments of this application;
[0049] Figure 8 A schematic diagram of the structure of a computer device provided in an embodiment of this application. Detailed Implementation
[0050] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of this application and are therefore merely examples, and should not be used to limit the scope of protection of this application.
[0051] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.
[0052] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, "multiple groups" means two or more, and "each" means each of the multiple, unless otherwise explicitly defined.
[0053] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.
[0054] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.
[0055] Unless otherwise specified, the order of execution steps in the embodiments of this application is not limited. It should also be noted that any step in the embodiments of this application can be executed independently, that is, the execution of any step in the above embodiments can be performed without depending on the execution of other steps.
[0056] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication between two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.
[0057] The harmonic injection method provided in this application can reduce the cost of harmonic injection and improve the convenience and stability of harmonic injection.
[0058] Figure 1 This is a schematic diagram of the voltage conversion circuit provided in the embodiments of this application, such as... Figure 1 As shown, the voltage conversion circuit includes a voltage input terminal, a filter circuit, and a series resonant converter circuit. The input terminal of the filter circuit is connected to the voltage input terminal, and the output terminal of the filter circuit is connected to the series resonant converter circuit. Additionally, the output terminal of the filter circuit is connected to the input terminal of the series resonant converter circuit, and the output terminal of the series resonant converter circuit is connected to the voltage output terminal.
[0059] The filter circuit includes a lead inductor L1 and an input capacitor C1. The first end of the lead inductor L1 is connected to the positive terminal of the voltage input terminal. The second end of the lead inductor L1 is connected to the positive input terminal of the series resonant converter circuit. The second end of the lead inductor L1 is also connected to the first end of the input capacitor C1. The second end of the input capacitor C1 is connected to the negative terminal of the voltage input terminal and the negative terminal of the series resonant converter circuit. Furthermore, the positive output terminal of the series resonant converter circuit is connected to the positive terminal of the voltage output terminal, and the negative output terminal of the series resonant converter circuit is connected to the negative terminal of the voltage output terminal.
[0060] For example, the series resonant converter circuit can be a series resonant converter (SRC).
[0061] Figure 2 This is a schematic diagram of the voltage conversion circuit provided in the embodiments of this application, such as... Figure 2 As shown, Figure 2 The voltage conversion circuit in the embodiment is compared to Figure 1The difference in the embodiments is that the series resonant converter circuit includes a switching circuit, a transformer, and a resonant rectifier circuit; wherein the resonant rectifier circuit includes a resonant circuit and a rectifier circuit; and the output terminal of the series resonant converter circuit is also connected in parallel with an output capacitor C2.
[0062] Figure 2 The diagram shows a switching circuit including a full-bridge inverter circuit, for example, a full-bridge inverter circuit using switching transistors. , , as well as Composition. In Figure 2 In other embodiments, the switching circuit may include a half-bridge inverter circuit, or may include a circuit consisting of other numbers of switching transistors.
[0063] The positive input terminal of the switching circuit is connected to the first terminal of the input capacitor C1, and the negative input terminal of the switching circuit is connected to the second terminal of the input capacitor C1. The positive input terminal of the switching circuit is connected to the first terminal of the primary winding of the transformer, and the negative input terminal of the switching circuit is connected to the second terminal of the primary winding of the transformer. The first terminal of the secondary winding of the transformer is connected to the positive input terminal of the resonant rectifier circuit, and the second terminal of the secondary winding of the transformer is connected to the negative input terminal of the resonant rectifier circuit. The positive output terminal of the resonant rectifier circuit is connected to the first terminal of the output capacitor C2, and the negative output terminal of the resonant rectifier circuit is connected to the second terminal of the output capacitor C2.
[0064] For example, the resonant circuit includes a resonant inductor L2, a resonant capacitor C3, and a resonant capacitor C4. The rectifier circuit includes a switching transistor. and switching transistor The first terminal of the transformer secondary side is connected to the first terminal of the resonant inductor L2, and the second terminal of the resonant inductor L2 is connected to the switching transistor. The first terminal of the resonant inductor L2 is connected to the second terminal of the switching transistor. The first terminal, the switching transistor The second terminal is connected to the first terminal of the resonant capacitor C3, and the switching transistor... The second terminal is also connected to the first terminal of the output capacitor C2; the second terminal of the resonant capacitor C3 is connected to the second terminal of the transformer secondary side; the second terminal of the resonant capacitor C3 is also connected to the first terminal of the resonant capacitor C4; the second terminal of the resonant capacitor C4 is connected to the switching transistor. The second terminal of the resonant capacitor C4 is also connected to the second terminal of the output capacitor C2.
[0065] It should be noted that, Figure 2 The embodiment shown is a series resonant converter circuit. In other embodiments, the series resonant converter circuit may have other implementations, and the embodiments of this application do not limit them.
[0066] The following uses the voltage value at the voltage input terminal. The inductance value of lead inductor L1 is The capacitance of the input capacitor C1 is The transformer's amplification factor is The inductance of the resonant inductor L2 is The capacitance of the resonant capacitor C3 is / 2, the capacitance of the resonant capacitor C4 is Taking / 2 as an example, the harmonic injection method in the embodiments of this application will be explained. Exemplarily, the voltage conversion circuit in the harmonic injection method can be... Figure 1 or Figure 2 Any voltage conversion circuit in the example. For instance, the amplification factor of a transformer can be the turns ratio of the transformer, that is, the ratio of the number of turns in the secondary winding to the number of turns in the primary winding.
[0067] In this embodiment of the application, in the voltage conversion circuit, lead inductance is the parasitic inductance caused by the circuit traces. For example, lead inductance is the parasitic inductance caused by the connecting wires from the power supply to the input terminal of the voltage conversion circuit.
[0068] by Figure 2 Taking the illustrated embodiment as an example, the components of the voltage conversion circuit in any embodiment of this application may include, in addition to the switching transistor (i.e., , , , , and Each component other than ).
[0069] The methods in any embodiment of this application can be applied to a processor or computer device. Exemplarily, a computer device may include one or a combination of at least two of the following: a server, a mobile phone, a tablet computer, a computer with transceiver capabilities, a handheld computer, a desktop computer, a virtual reality (VR) device, an augmented reality (AR) device, and so on.
[0070] Figure 3 This is a schematic flowchart of the harmonic injection method provided in the embodiments of this application, as shown below. Figure 3 As shown, the voltage conversion circuit includes a voltage input terminal, a filter circuit, and a series resonant conversion circuit; the input terminal of the filter circuit is connected to the voltage input terminal, and the output terminal of the filter circuit is connected to the series resonant conversion circuit, which includes a transformer, a resonant inductor, and a resonant capacitor; the method includes the following steps:
[0071] S301. Based on the current-voltage loop equation established by the complex frequency domain equivalent circuit model of the voltage transformation circuit, the expression of the transient current in the complex frequency domain of the resonant inductor in the half-wave time domain is determined.
[0072] For example, the primary side of the transformer is connected to the output of the filter circuit, and the secondary side of the transformer is connected to the output of the voltage conversion circuit through a series resonant inductor and resonant capacitor.
[0073] In some embodiments, a complex frequency domain equivalent circuit model of the voltage conversion circuit can be established based on the voltage conversion circuit. For example, the complex frequency domain parameters of each component in the voltage conversion circuit are determined according to the parameters of each component in the voltage conversion circuit; the complex frequency domain parameters of each component are equivalent to the primary or secondary side of the transformer to obtain the equivalent complex frequency domain parameters of each component; and the complex frequency domain equivalent circuit model of the voltage conversion circuit is formed according to the connection relationship between each component in the voltage conversion circuit and the equivalent complex frequency domain parameters of each component.
[0074] The half-wave time domain can include the positive half-wave time domain and the negative half-wave time domain. Since the transient current value in the complex frequency domain of the positive half-wave time domain is symmetrically set with the transient current value in the complex frequency domain of the negative half-wave time domain, and the waveform of the negative half-wave current is symmetrical with the positive half-wave along the time axis, the capacitance expression of the input capacitor in the filter circuit can be obtained by analyzing the transient current expression in the complex frequency domain of the half-wave time domain of the resonant inductor. The capacitance expression of the input capacitor in the filter circuit not only conforms to the operating conditions of the voltage conversion circuit in the positive half-wave time domain, but also conforms to the operating conditions of the voltage conversion circuit in the negative half-wave time domain.
[0075] The following describes some implementation methods for establishing a complex frequency domain equivalent circuit model of a voltage conversion circuit: Using the transformer's amplification factor, complex frequency domain secondary-side equivalent transformations are performed on the input voltage value, the electrical parameters of the lead inductor, and the electrical parameters of the input capacitor to obtain the complex frequency domain equivalent input voltage value, the complex frequency domain equivalent parameters of the lead inductor, and the complex frequency domain equivalent parameters of the input capacitor. Complex frequency domain transformations are then performed on the electrical parameters of the resonant element and the output voltage value to obtain the complex frequency domain equivalent parameters of the resonant element and the complex frequency domain output voltage value. Based on the complex frequency domain equivalent input voltage value, the complex frequency domain equivalent parameters of the lead inductor, the complex frequency domain equivalent parameters of the input capacitor, the complex frequency domain equivalent parameters of the resonant element, and the complex frequency domain output voltage value, and according to the connection relationships between the components in the voltage conversion circuit, a complex frequency domain equivalent circuit model is established. For example, the resonant element may include a resonant inductor and a resonant capacitor.
[0076] It should be noted that the embodiments of this application exemplify a scheme in which the components on the primary side of the transformer in the voltage conversion circuit are equivalent to those on the secondary side. In other embodiments, the components on the secondary side of the transformer in the voltage conversion circuit can also be equivalent to those on the primary side, and the implementation method is similar to the scheme in the embodiments of this application in which the components on the primary side of the transformer in the voltage conversion circuit are equivalent to those on the secondary side.
[0077] In some embodiments, the transformer's amplification factor is used to perform complex frequency domain secondary-side equivalent transformations on the input voltage value, the electrical parameters of the lead inductance, and the electrical parameters of the input capacitance, respectively, to obtain complex frequency domain equivalent input voltage values, complex frequency domain equivalent parameters of the lead inductance, and complex frequency domain equivalent parameters of the input capacitance. This may include: performing a complex frequency domain transformation on the input voltage value to obtain a complex frequency domain input voltage value, and, based on the transformer's amplification factor, equating the complex frequency domain input voltage value to the secondary side of the series resonant transformer circuit to obtain complex frequency domain equivalents. Effective input voltage value; Perform complex frequency domain transformation on the electrical parameters of the lead inductor to obtain the complex frequency domain parameters of the lead inductor, and according to the amplification factor of the transformer, apply the complex frequency domain parameters of the lead inductor to the secondary side of the series resonant transformer circuit to obtain the complex frequency domain equivalent parameters of the lead inductor; Perform complex frequency domain transformation on the electrical parameters of the input capacitor to obtain the complex frequency domain parameters of the input capacitor, and according to the amplification factor of the transformer, apply the complex frequency domain parameters of the input capacitor to the secondary side of the series resonant transformer circuit to obtain the complex frequency domain equivalent parameters of the input capacitor.
[0078] In some embodiments, the electrical parameters of the lead inductor are transformed in the complex frequency domain to obtain the complex frequency domain parameters of the lead inductor. Then, based on the transformer's amplification factor, the complex frequency domain parameters of the lead inductor are equivalently represented to the secondary side of the series resonant transformer circuit to obtain the equivalent complex frequency domain parameters of the lead inductor. This includes: transforming the voltage in the electrical parameters of the lead inductor in the complex frequency domain to obtain the initial complex frequency domain voltage of the lead inductor, and then, based on the transformer's amplification factor, representing the initial complex frequency domain voltage of the lead inductor as equivalent to the series resonant transformer circuit. The secondary side of the transformer circuit is transformed to obtain the complex frequency domain equivalent voltage of the lead inductor. The inductance value in the electrical parameters of the lead inductor is transformed in the complex frequency domain to obtain the complex frequency domain inductance value of the lead inductor. Based on the amplification factor of the transformer, the complex frequency domain inductance value of the lead inductor is equivalently applied to the secondary side of the series resonant transformer circuit to obtain the complex frequency domain equivalent inductance value of the lead inductor. The combination of the complex frequency domain equivalent voltage and the complex frequency domain equivalent inductance value of the lead inductor is determined as the complex frequency domain equivalent parameter of the lead inductor.
[0079] In some embodiments, the electrical parameters of the input capacitor are transformed in the complex frequency domain to obtain the complex frequency domain parameters of the input capacitor. Based on the transformer's amplification factor, the complex frequency domain parameters of the input capacitor are then equivalently mapped to the secondary side of the series resonant transformer circuit to obtain the complex frequency domain equivalent parameters of the input capacitor. This includes: transforming the voltage in the electrical parameters of the input capacitor in the complex frequency domain to obtain the complex frequency domain voltage of the input capacitor; and based on the transformer's amplification factor, equating the complex frequency domain voltage of the input capacitor to the secondary side of the series resonant transformer circuit to obtain the complex frequency domain equivalent voltage of the input capacitor; transforming the capacitance value in the electrical parameters of the input capacitor in the complex frequency domain to obtain the complex frequency domain capacitance value of the input capacitor; and based on the transformer's amplification factor, equating the complex frequency domain capacitance value of the input capacitor to the secondary side of the series resonant transformer circuit to obtain the complex frequency domain equivalent capacitance value of the input capacitor; and determining the combination of the complex frequency domain equivalent voltage and the complex frequency domain equivalent capacitance value of the input capacitor as the complex frequency domain equivalent parameters of the input capacitor.
[0080] In some embodiments, the electrical parameters of the resonant element include the inductance value of the resonant inductor and the capacitance value of the resonant capacitor. Performing complex frequency domain transformations on the electrical parameters and output voltage value of the resonant element to obtain the complex frequency domain equivalent parameters and complex frequency domain output voltage value of the resonant element includes: performing complex frequency domain transformations on the inductance value of the resonant inductor and the capacitance value of the resonant capacitor to obtain the complex frequency domain inductance value of the resonant inductor and the complex frequency domain capacitance value of the resonant capacitor; determining the combination of the complex frequency domain inductance value of the resonant inductor and the complex frequency domain capacitance value of the resonant capacitor as the complex frequency domain equivalent parameters of the resonant element; and performing a complex frequency domain transformation on the output voltage value to obtain the complex frequency domain output voltage value.
[0081] Figure 4 A schematic diagram of the complex frequency domain equivalent circuit model of the voltage conversion circuit provided in some embodiments, such as... Figure 4 As shown, the complex frequency domain equivalent circuit model includes the complex frequency domain equivalent input voltage at the voltage input terminal, the complex frequency domain equivalent voltage of the lead inductor, the complex frequency domain equivalent impedance of the lead inductor, the complex frequency domain equivalent voltage of the input capacitor, the complex frequency domain equivalent impedance of the input capacitor, the complex frequency domain impedance of the resonant capacitor, the complex frequency domain impedance of the resonant inductor, and the complex frequency domain output voltage at the voltage output terminal of the voltage conversion circuit.
[0082] by Figure 2 Taking the voltage conversion circuit shown as an example, in Figure 4 In the complex frequency domain equivalent circuit model, the voltage value of the complex frequency domain equivalent input voltage is The voltage value of the lead inductance in the complex frequency domain is The complex frequency domain equivalent impedance of the lead inductor is an impedance value of The voltage value of the input capacitor in the complex frequency domain is The impedance value of the input capacitor in the complex frequency domain is The impedance value of the resonant capacitor in the complex frequency domain is The impedance value of the complex frequency domain impedance of the resonant inductor is The voltage value of the complex frequency domain output voltage at the voltage output terminal is .in, This indicates the transformer's amplification factor (i.e., the transformer's turns ratio). This indicates the input voltage value at the voltage input terminal; Represents complex frequency; Indicates the inductance value of the lead wire; This indicates the initial current value of the lead inductance; Indicates the capacitance value of the input capacitor; This indicates the capacitance value of the resonant capacitor; This indicates the inductance value of the resonant inductor; This represents the equivalent quality factor of the series resonant converter circuit. For example, if the output is a full-bridge circuit and the output capacitance is large enough, It will be zero.
[0083] At the initial moment, the current in the resonant inductor... =0, input capacitor voltage = Therefore, the equivalent initial voltage of the resonant capacitor = The initial current of the lead inductance = .
[0084] Current-voltage loop equations are algebraic equations describing the relationship between voltage and current in a closed loop of a circuit. For example, current-voltage loop equations can include complex frequency domain loop voltage equations and complex frequency domain loop current equations. The complex frequency domain loop voltage equations are established based on Kirchhoff's voltage law, and the complex frequency domain loop current equations are established based on Kirchhoff's current law.
[0085] In some embodiments, once the complex frequency domain equivalent circuit model is established, the current and voltage loop equations can be established based on the complex frequency domain equivalent circuit model; and based on the current and voltage loop equations, the complex frequency domain transient current expression of the resonant inductor in the half-wave time domain can be determined.
[0086] For example, the current-voltage loop equations may include: a first complex frequency domain loop voltage equation, a second complex frequency domain loop voltage equation, and a complex frequency domain current loop equation. The first complex frequency domain loop voltage equation is the complex frequency domain voltage loop equation for the primary side of the transformer, the second complex frequency domain loop voltage equation is the complex frequency domain voltage loop equation for the secondary side of the transformer, and the complex frequency domain current loop equation is the current shunt equation for the lead inductance at the input terminal of the voltage conversion circuit.
[0087] In some embodiments, the complex frequency domain transient current expression of the resonant inductor in the half-wave time domain is determined based on the current-voltage loop equations established by the complex frequency domain equivalent circuit model of the voltage transformation circuit. This includes: determining the first complex frequency domain loop voltage equation, the second complex frequency domain loop voltage equation, and the complex frequency domain current loop equation of the transformer's primary side based on the complex frequency domain equivalent circuit model of the voltage transformation circuit and Kirchhoff's laws; and determining the complex frequency domain transient current expression of the resonant inductor in the half-wave time domain based on the first complex frequency domain loop voltage equation, the second complex frequency domain loop voltage equation, and the complex frequency domain current loop equation.
[0088] In equivalent circuit Figure 4 The voltage equations for the first complex frequency domain loop, the voltage equation for the second complex frequency domain loop, and the current equation for the complex frequency domain loop are as follows.
[0089] The expression for the voltage equation of the first complex frequency domain loop is:
[0090] .
[0091] The expression for the voltage equation of the second complex frequency domain loop is:
[0092] .
[0093] The expression for the complex frequency domain current loop equation is:
[0094] .
[0095] in, Represents complex frequency; This indicates the input voltage value at the voltage input terminal; Indicates the amplification factor of the transformer; Indicates the inductance value of the lead wire; This represents the complex frequency domain current value of the lead inductance; This indicates the initial current value of the lead inductance; This indicates the capacitance value of the input capacitor; This represents the complex frequency domain current value of the input capacitor; This indicates the input voltage value at the voltage input terminal; This represents the complex frequency domain current value of the resonant inductor; This indicates the inductance value of the resonant inductor; This indicates the capacitance value of the resonant capacitor; This represents the equivalent quality factor of the series resonant converter circuit. This represents the complex frequency domain current value of the resonant inductor.
[0096] In some embodiments, the system of multiple linear equations is solved for the first complex frequency domain loop voltage equation, the second complex frequency domain loop voltage equation, and the complex frequency domain current loop equation to obtain the complex frequency domain transient current expression:
[0097] ;
[0098] in, This represents the complex frequency domain transient current value in the half-wave time domain of the resonant inductor. Indicates the amplification factor of the transformer; This indicates the input voltage value at the voltage input terminal; Represents complex frequency; Indicates the inductance value of the lead wire; This indicates the initial current value of the lead inductance; Indicates the capacitance value of the input capacitor; This indicates the capacitance value of the resonant capacitor; This indicates the inductance value of the resonant inductor; It represents the equivalent quality factor of a series resonant converter circuit.
[0099] S302. Based on the complex frequency domain transient current expression, obtain the time domain current expression of the resonant inductor that includes the fundamental angular frequency value and the harmonic angular frequency value.
[0100] Among them, the fundamental angular frequency is the angular frequency value when the voltage conversion circuit resonates, the harmonic angular frequency value is an odd multiple of the fundamental angular frequency value, the fundamental angular frequency value and the harmonic angular frequency value are both related to the component parameters of the filter circuit and the series resonant conversion circuit, and the harmonic angular frequency value is the angular frequency value of the harmonic component injected into the voltage conversion circuit.
[0101] Among them, the harmonic angular frequency value refers to the angular frequency value of other harmonic components in the time-domain current besides the fundamental wave.
[0102] The fundamental angular frequency value can be determined based on the following: , , , , as well as .
[0103] The harmonic angular frequency value can be determined based on the following: , , , , as well as .
[0104] The time-domain current expression of a resonant inductor can represent the time-domain current value of the resonant inductor. Relationship with the following: , , , , , , , .
[0105] Figure 5 This is a schematic flowchart of the harmonic injection method provided in the embodiments of this application, as shown below. Figure 5 As shown, Figure 5 The illustrated embodiments and Figure 3 The difference in the illustrated embodiments is that, Figure 5 In the illustrated embodiment, S302 may include S3021 and S3022.
[0106] S3021. Perform partial fraction decomposition on the complex frequency domain transient current expression to obtain the complex frequency domain decomposition of the resonant inductor with respect to the fundamental angular frequency and harmonic angular frequency.
[0107] S3022. Perform an inverse Laplace transform on the complex frequency domain decomposition to obtain the time-domain current expression of the resonant inductor, which includes the fundamental angular frequency and harmonic angular frequency values.
[0108] Partial fraction decomposition is an algebraic operation method that decomposes a rational fractional function into the sum of several simple rational fractions.
[0109] In some embodiments, the complex frequency domain transient current value of the resonant inductor in the half-wave time domain is decomposed using the partial fraction method. Decompose the expression to obtain the complex frequency domain decomposition:
[0110] ;
[0111] in, This represents the complex frequency domain current value of the resonant inductor.
[0112] In some embodiments, the time-domain current expression of the resonant inductor is:
[0113] ;
[0114] in, Represents resonant inductance The time-domain current value.
[0115] Indicates the fundamental angular frequency value; A represents the harmonic angular frequency value; B represents the amplitude of the fundamental component on the cosine wave; C represents the amplitude of the harmonic component on the cosine wave; D represents the amplitude of the harmonic component on the sine wave.
[0116] ; ;
[0117] ; ;
[0118] ; ;
[0119] ; ;
[0120] in, This indicates the capacitance value of the resonant capacitor; Indicates the inductance value of the lead wire; Indicates the amplification factor of the transformer; This indicates the capacitance value of the input capacitor; This indicates the inductance value of the resonant inductor; This indicates the initial current value of the lead inductance; This represents the equivalent quality factor of the series resonant converter circuit. This indicates the input voltage value at the voltage input terminal; This represents the output power value of the series resonant converter circuit.
[0121] In the technical solution provided in this application embodiment, the complex frequency domain transient current expression is determined by multi-dimensional constraints of the complex frequency domain equivalent circuit model, the primary side voltage of the transformer, the secondary side voltage of the transformer, and the current in the complex frequency domain equivalent circuit model. This ensures the rigor of the complex frequency domain transient current expression, improves the accuracy of the determined complex frequency domain transient current expression, and thus improves the accuracy of the determined input capacitor value expression.
[0122] S303. When the harmonic angular frequency is a multiple of the fundamental angular frequency, determine the expression for the capacitance value of the input capacitor in the filter circuit.
[0123] The capacitance expression characterizes the relationship between the capacitance of the input capacitor and the target multiple, the inductance of the lead inductance at the voltage input terminal of the filter circuit, the amplification factor of the transformer, the inductance of the resonant inductor, and the capacitance of the resonant capacitor.
[0124] The fundamental angular frequency value, whose harmonic angular frequency is a multiple of the target, can be expressed as: ;in, Indicates the fundamental angular frequency value; Indicates the harmonic angular frequency value; Indicates the target multiple.
[0125] Since the voltage output of the switching circuit in the series resonant converter is a symmetrical square wave, according to Fourier series decomposition, the spectrum of the symmetrical square wave contains only the fundamental wave and odd harmonics, with no even harmonic components. Therefore, the target multiple can be any odd number greater than 1. For example, the target multiple can be 3, 5, 7, or 9, etc.
[0126] The harmonic order of the injected harmonic component is the same as the target multiple. For example, if the target multiple is 3, the harmonic order of the injected harmonic component is 3. As another example, if the target multiple is 5, the harmonic order of the injected harmonic component is 5.
[0127] In some embodiments, the method may further include the following step: determining the target capacitance value of the input capacitor based on the capacitance value expression of the input capacitor and the target harmonic order of the harmonic component to be injected. Thus, when the capacitance value of the input capacitor set in the voltage conversion circuit is the target capacitance value, the harmonic component of the target harmonic order is injected into the voltage conversion circuit.
[0128] In some implementations, the target harmonic order of the harmonic component to be injected can be preset. For example, the target harmonic order can be preset to the third, fifth, seventh, or ninth order, etc.
[0129] In other embodiments, the target harmonic order of the harmonic component to be injected can be determined by: determining the candidate capacitance value of the input capacitor corresponding to each harmonic order based on each harmonic order, the fundamental angular frequency value, and the harmonic angular frequency value among a plurality of preset harmonic orders; and determining the target harmonic based on the candidate capacitance value of the input capacitor corresponding to each harmonic order.
[0130] in, (Through resonant inductor) The current) passes through a resonant angular frequency of The fundamental frequency and odd-order harmonics constitute the signal, thus completing the odd-order harmonic injection. Taking the third harmonic as an example, experiments have shown that the peak value of the resonant current can be reduced by about 15% through the injection of the third harmonic. That is, in the embodiments of this application, the lead inductance is fully utilized. It is a parasitic parameter of the circuit and does not increase the additional cost. Harmonic injection is achieved only by adjusting the capacitance value of the input capacitor.
[0131] In the technical solution provided in this application embodiment, by establishing the current-voltage loop equation of the voltage conversion circuit in the complex frequency domain, the expression of the transient current in the complex frequency domain of the resonant inductor in the half-wave time domain is derived, thereby obtaining the fundamental angular frequency value and the harmonic angular frequency value. Then, combined with the fundamental angular frequency value whose harmonic angular frequency value is a multiple of the target fundamental angular frequency value, the capacitance expression of the input capacitor in the filter circuit is determined. In the determined series resonant conversion circuit, when the target multiple of the fundamental harmonic to be injected is determined, the angular frequency value of the injected harmonic can be obtained through the input capacitor at the input end of the determined series resonant conversion circuit, thereby realizing the injection of the target multiple of the harmonic in the voltage conversion circuit. Thus, the harmonic injection method of this application is portable, meaning it can be applied to series resonant converter circuits with different circuit parameters. Furthermore, it avoids adding a hardware multi-resonant structure to the voltage conversion circuit, thereby reducing the cost of harmonic injection. It also eliminates the need to determine the electrical parameters of the multi-resonant structure and design complex multi-harmonic control algorithms, thus avoiding increased computational complexity due to multiple control quantities. Therefore, it significantly simplifies the method of injecting harmonic components into the voltage conversion circuit and reduces the instability caused by inaccurate determination of the electrical parameters of the multi-resonant structure or limited accuracy of the multi-harmonic control algorithm, thereby improving the convenience and stability of harmonic injection.
[0132] In some embodiments, when the harmonic angular frequency is a fundamental angular frequency value that is a multiple of the target value, determining the capacitance expression of the input capacitor in the filter circuit includes:
[0133] based on , , as well as The capacitance expression is determined as follows:
[0134] ;
[0135] in, Indicates the target multiple; This indicates the capacitance value of the resonant capacitor; Indicates the inductance value of the lead wire; Indicates the amplification factor of the transformer; This indicates the capacitance value of the input capacitor; This represents the inductance value of the resonant inductor.
[0136] In this embodiment, within a defined series resonant converter circuit, as long as the series resonant converter circuit for which the harmonic components to be injected is determined, the parameters of the resonant circuit and transformer components are known. When the application scenario of the series resonant converter circuit is determined, the lead inductance is also determined. Therefore, when it is necessary to inject a harmonic with an angular frequency M times that of the fundamental wave, according to the aforementioned C... inOnce the input capacitor value is determined by the formula, the angular frequency of the injected harmonic is determined using the ω2 formula mentioned above.
[0137] For example, another =3, that is Then the following expression can be derived: .
[0138] In the technical solution provided in this application embodiment, by using the capacitance value expression of the input capacitor in the filter circuit, when the parameters of other components besides the input capacitor in the voltage conversion circuit are determined, the capacitance value of the input capacitor in the filter circuit can be uniquely determined, avoiding harmonic injection deviation caused by parameter mismatch in traditional design, and ensuring that the target harmonic component can be accurately injected into the circuit.
[0139] The following example uses a voltage conversion circuit with an input voltage of 3V and an output power of 500W to illustrate the changes in the current value of the resonant inductor when different harmonics (3rd, 7th, and 5th) are injected and when no harmonics are injected.
[0140] Figure 6 For some embodiments, the switching transistor under different harmonic injection conditions and A schematic diagram showing the changes in voltage across a series circuit and current in the resonant inductor over time, as shown below. Figure 6 As shown, Figure 6 The horizontal axis represents time, in seconds, and the vertical axis represents V. g1、4 Indicates the switching transistor and The voltage across the series circuit, I on the vertical axis. Lr_p This represents the current value of the resonant inductor. For example, the current value I of the resonant inductor... Lr_p To convert the current value of the resonant inductor on the secondary side of the transformer to the current value on the primary side of the transformer, the current measurement value can be reduced by converting the current value of the resonant inductor on the secondary side of the transformer to the current value on the primary side of the transformer, thereby avoiding the situation where the current value is too large to be measured.
[0141] Figure 6 The effects of different harmonic orders injected into the voltage conversion circuit and the absence of injected harmonics on the switching transistors are described respectively. and The voltage (V) across a series circuit g1、4 The variation of the resonant inductor with time, and the current I of the resonant inductor. Lr_p The pattern of change over time.
[0142] like Figure 6 As shown, in the switching transistor and When the voltage change patterns across the series circuits are the same, the peak current of the primary resonant inductor when injected with the third harmonic and when no harmonics are injected is significantly smaller than the peak current of the resonant inductor when no harmonics are injected. Thus, by injecting the third harmonic into the voltage conversion circuit, the conduction loss and thermal stress of the resonant inductor can be reduced, and the radiation interference of the voltage conversion circuit can also be effectively reduced.
[0143] This application embodiment can also provide a voltage conversion circuit, which includes a voltage input terminal, a filter circuit, and a series resonant conversion circuit; the input terminal of the filter circuit is connected to the voltage input terminal, and the output terminal of the filter circuit is connected to the series resonant conversion circuit.
[0144] The voltage conversion circuit can be referenced. Figure 1 or Figure 2 The description of the embodiments will not be repeated here.
[0145] The capacitance value of the input capacitor of the filter circuit is determined according to the capacitance value expression, which is determined according to the harmonic injection method in any of the above embodiments.
[0146] Based on the same concept, this application also provides an electronic device for implementing the harmonic injection method described above. The solution provided by this device is similar to the implementation described in the above method; therefore, the specific limitations in one or more electronic device embodiments provided below can be found in the limitations of the harmonic injection method described above, and will not be repeated here.
[0147] In one exemplary embodiment, Figure 7 Schematic diagrams of the structure of electronic devices provided in some embodiments, such as Figure 7 As shown, the electronic device 700 includes:
[0148] The transient current expression determination module 701 is used to determine the complex frequency domain transient current expression of the resonant inductor based on the current and voltage loop equations established by the complex frequency domain equivalent circuit model of the voltage transformation circuit.
[0149] The time-domain current expression determination module 702 is used to obtain the time-domain current expression of the resonant inductor, which includes the fundamental angular frequency value and the harmonic angular frequency value, based on the complex frequency domain transient current expression. The fundamental angular frequency value is the angular frequency value when the voltage conversion circuit resonates, and the harmonic angular frequency value is an odd multiple of the fundamental angular frequency value. Both the fundamental angular frequency value and the harmonic angular frequency value are related to the component parameters of the filter circuit and the series resonant conversion circuit. The harmonic angular frequency value is the angular frequency value of the harmonic component injected into the voltage conversion circuit.
[0150] The capacitance expression determination module 703 is used to determine the capacitance expression of the input capacitor in the filter circuit when the harmonic angular frequency is a fundamental angular frequency value that is a multiple of the target. The capacitance expression characterizes the relationship between the capacitance value of the input capacitor, the target multiple, the inductance value of the lead inductance at the voltage input terminal of the filter circuit, the amplification factor of the transformer, the inductance value of the resonant inductor, and the capacitance value of the resonant capacitor.
[0151] The descriptions of the above device embodiments are similar to those of the above method embodiments, and have similar beneficial effects. For technical details not disclosed in the device embodiments of this application, please refer to the descriptions of the method embodiments of this application for understanding.
[0152] Each module in the aforementioned electronic device can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in the processor of a computer device in hardware form or independent of it, or stored in the memory of a computer device in software form, so that the processor can call and execute the operations corresponding to each module.
[0153] In one exemplary embodiment, Figure 8 This is a schematic diagram of the structure of a computer device provided in some embodiments. The computer device includes a processor, memory, input / output interface, communication interface, display unit, and input device. The processor, memory, and input / output interface are connected via a system bus, and the communication interface, display unit, and input device are also connected to the system bus via the input / output interface. The processor of the computer device provides computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and internal memory. The non-volatile storage medium stores the operating system and computer programs. The internal memory provides an environment for the operation of the operating system and computer programs in the non-volatile storage medium. The input / output interface of the computer device is used for exchanging information between the processor and external devices. The communication interface of the computer device is used for wired or wireless communication with external terminals. Wireless communication can be achieved through Wireless Fidelity (WIFI), mobile cellular networks, Near Field Communication (NFC), or other technologies. When the computer program is executed by the processor, it implements a harmonic injection method. The display unit of the computer device is used to form a visually visible image and can be a display screen, a projection device, or a virtual reality imaging device. The display screen can be an LCD screen or an e-ink screen. The input device of the computer device can be a touch layer covering the display screen, or buttons, trackballs, or touchpads set on the casing of the computer device, or external keyboards, touchpads, or mice, etc.
[0154] Those skilled in the art will understand that Figure 8 The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the computer device to which the present application is applied. Specific computer devices may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.
[0155] For example, a computer device includes a memory and a processor, the memory storing a computer program, and the processor executing the computer program to implement the steps of the method of any of the above embodiments.
[0156] In one embodiment, a computer-readable storage medium is provided, wherein a computer program, when executed by a processor, implements the steps of the method provided in any of the above embodiments.
[0157] In one embodiment, a computer program product is provided, including a computer program that, when executed by a processor, implements the steps of the method provided in any of the above embodiments.
[0158] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the methods described above.
[0159] The processor, functional modules, or functional units in any embodiment of this application may include an integration of one or more of the following: a general-purpose processor, an application-specific integrated circuit (ASIC), a digital signal processor (DSP), a digital signal processing device (DSPD), a programmable logic device (PLD), a field-programmable gate array (FPGA), a central processing unit (CPU), a graphics processing unit (GPU), an embedded neural network processing unit (NPU), a controller, a microcontroller, a microprocessor, a programmable logic device, a discrete gate or transistor logic device, a discrete hardware component, a quantum computing-based data processing logic unit, an artificial intelligence (AI) processor, etc. The general-purpose processor may be a microprocessor or any conventional processor.
[0160] The memory or computer-readable storage medium in any embodiment of this application may include at least one of non-volatile memory and volatile memory. Non-volatile memory includes integration of one or more of the following: Read Only Memory (ROM), Programmable Read-Only Memory (PROM), Erasable Programmable Read-Only Memory (EPROM), Electrically Erasable Programmable Read-Only Memory (EEPROM), Ferromagnetic Random Access Memory (FRAM), Flash Memory, Magnetic Surface Memory, Optical Disc, Compact Disc Read-Only Memory (CD-ROM), Magnetic Tape, Floppy Disk, Flash Memory, Optical Memory, High-Density Embedded Non-Volatile Memory, Resistive Random Access Memory (ReRAM), Magnetoresistive Random Access Memory (MRAM), Ferroelectric Random Access Memory (FRAM), Phase Change Memory (PCM), Graphene Memory, Volatile Memory, etc. Volatile memory includes one or more of the following: Random Access Memory (RAM) or external cache memory. By way of illustration and not limitation, RAM can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM).
[0161] The acquisition, transmission, storage, use, and processing of data in this application comply with relevant national laws and regulations. It should be noted that certain software, components, models, and other existing industry solutions may be mentioned in the embodiments of this application. These should be considered exemplary, intended only to illustrate the feasibility of implementing the technical solution of this application, and do not imply that the applicant has already used or necessarily used such solutions.
[0162] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this application.
[0163] The above embodiments are merely illustrative of several implementation methods of this application, and their descriptions are relatively specific and detailed. However, they should not be construed as limiting the scope of this application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.
Claims
1. A harmonic injection method, characterized in that, The voltage conversion circuit includes a voltage input terminal, a filter circuit, and a series resonant conversion circuit; the input terminal of the filter circuit is connected to the voltage input terminal, and the output terminal of the filter circuit is connected to the series resonant conversion circuit, which includes a transformer, a resonant inductor, and a resonant capacitor; the method includes: Based on the current-voltage loop equation established by the complex frequency domain equivalent circuit model of the voltage transformation circuit, the complex frequency domain transient current expression of the resonant inductor in the half-wave time domain is determined. Based on the complex frequency domain transient current expression, a time-domain current expression for the resonant inductor, including the fundamental angular frequency and harmonic angular frequency, is obtained. The fundamental angular frequency is the angular frequency at which the voltage conversion circuit resonates. The harmonic angular frequency is an odd multiple of the fundamental angular frequency. Both the fundamental and harmonic angular frequencies are related to the component parameters of the filter circuit and the series resonant conversion circuit. The harmonic angular frequency is the angular frequency of the harmonic component injected into the voltage conversion circuit. When the harmonic angular frequency is a fundamental angular frequency value that is a multiple of the target, the capacitance value expression of the input capacitor in the filter circuit is determined, wherein the capacitance value expression characterizes the relationship between the capacitance value of the input capacitor, the target multiple, the inductance value of the lead inductance of the filter circuit at the voltage input terminal, the amplification factor of the transformer, the inductance value of the resonant inductor, and the capacitance value of the resonant capacitor.
2. The method according to claim 1, characterized in that, The process of obtaining the time-domain current expression of the resonant inductor, which includes the fundamental angular frequency and harmonic angular frequency values, based on the complex frequency domain transient current expression, includes: The complex frequency domain transient current expression is decomposed by partial fraction method to obtain the complex frequency domain decomposition expression of the resonant inductor with respect to the fundamental angular frequency value and the harmonic angular frequency value; By performing an inverse Laplace transform on the complex frequency domain decomposition, the time-domain current expression of the resonant inductor is obtained.
3. The method according to claim 1 or 2, characterized in that, The time-domain current expression of the resonant inductor is: ； in, Indicates the resonant inductor The time-domain current value; This represents the fundamental angular frequency value; A represents the harmonic angular frequency value; B represents the amplitude of the fundamental component on the cosine wave; C represents the amplitude of the harmonic component on the cosine wave; D represents the amplitude of the harmonic component on the sine wave. ； ； ； ； ； ； ； ； This indicates the capacitance value of the resonant capacitor; This indicates the inductance value of the lead inductance; This indicates the amplification factor of the transformer; This indicates the capacitance value of the input capacitor; This represents the inductance value of the resonant inductor; This indicates the initial current value of the lead inductance; This represents the equivalent quality factor of the series resonant converter circuit. This indicates the input voltage value at the voltage input terminal; This represents the output power value of the series resonant converter circuit.
4. The method according to claim 1 or 2, characterized in that, When the harmonic angular frequency is a fundamental angular frequency value that is a multiple of the target value, determining the capacitance expression of the input capacitor in the filter circuit includes: based on , , as well as The capacitance expression is determined as follows: ； in, This represents the fundamental angular frequency value; This represents the harmonic angular frequency value; Indicates the target multiple; This indicates the capacitance value of the resonant capacitor; This indicates the inductance value of the lead inductor; This indicates the amplification factor of the transformer; This indicates the capacitance value of the input capacitor; This represents the inductance value of the resonant inductor.
5. The method according to claim 1 or 2, characterized in that, The current-voltage loop equation established based on the complex frequency domain equivalent circuit model of the voltage transformation circuit determines the complex frequency domain transient current expression of the resonant inductor in the half-wave time domain, including: Based on the complex frequency domain equivalent circuit model of the voltage transformation circuit and Kirchhoff's laws, the first complex frequency domain loop voltage equation, the second complex frequency domain loop voltage equation, and the complex frequency domain current loop equation of the transformer are determined. Based on the first complex frequency domain loop voltage equation, the second complex frequency domain loop voltage equation, and the complex frequency domain current loop equation, the complex frequency domain transient current expression of the resonant inductor in the half-wave time domain is determined. Wherein, the first complex frequency domain loop voltage equation is the complex frequency domain voltage loop equation of the primary side of the transformer, the second complex frequency domain loop voltage equation is the complex frequency domain voltage loop equation of the secondary side of the transformer, and the complex frequency domain current loop equation is the current shunt equation of the lead inductance at the input terminal of the voltage conversion circuit.
6. The method according to claim 5, characterized in that, The expression for the voltage equation of the first complex frequency domain loop is: ； in, This indicates the input voltage value at the voltage input terminal; This indicates the amplification factor of the transformer; Represents complex frequency; This indicates the inductance value of the lead inductor; This represents the complex frequency domain current value of the lead inductance; This indicates the initial current value of the lead inductance; This indicates the capacitance value of the input capacitor; This represents the complex frequency domain current value of the input capacitor.
7. The method according to claim 5, characterized in that, The expression for the second complex frequency domain loop voltage equation is: ； in, This indicates the amplification factor of the transformer; Represents complex frequency; This indicates the capacitance value of the input capacitor; This represents the complex frequency domain current value of the input capacitor; This indicates the input voltage value at the voltage input terminal; This represents the complex frequency domain current value of the resonant inductor; This represents the inductance value of the resonant inductor; This indicates the capacitance value of the resonant capacitor; This represents the equivalent quality factor of the series resonant converter circuit.
8. The method according to claim 5, characterized in that, The expression for the complex frequency domain current loop equation is: ； in, This represents the complex frequency domain current value of the lead inductance; This represents the complex frequency domain current value of the input capacitor; This represents the complex frequency domain current value of the resonant inductor.
9. A voltage conversion circuit, characterized in that, The voltage conversion circuit includes a voltage input terminal, a filter circuit, and a series resonant conversion circuit; the input terminal of the filter circuit is connected to the voltage input terminal, and the output terminal of the filter circuit is connected to the series resonant conversion circuit. The capacitance value of the input capacitor of the filter circuit is determined according to the capacitance value expression of the input capacitor, which is determined by the harmonic injection method according to any one of claims 1-8.
10. A computer storage medium, characterized in that, When the computer program in the computer storage medium is executed by a processor, it implements the steps of the method according to any one of claims 1 to 8.