Voltage-stabilizing and current-sharing control method and device for three-phase interleaving LLC converter

Abstract

The invention relates to a voltage-stabilizing and current-sharing control method and device for a three-phase interleaving LLC converter, and the method comprises the steps: obtaining the output voltage and output current of each three-phase interleaving LLC circuit in real time, carrying out the voltage-stabilizing and current-sharing control of each three-phase interleaving LLC circuit, and carrying out the voltage-stabilizing and current-sharing control of each three-phase interleaving LLC circuit; based on a given reference voltage, an injection signal and the output voltage, determining a currently output reference current by using a voltage loop; and based on the current reference current and the output current, determining the switching frequency of the current output by using a current loop, the output voltage and the output current of the three-phase interleaving LLC converter are regulated and controlled based on the switching frequencies, the phase difference of the injection signals of the three-phase interleaving LLC circuits is a fixed value, and the sum of the phase differences is 360 degrees. And the power is actively distributed to achieve the effects of reducing output voltage ripples and equalizing current.

Description

Technical Field

[0001] The present application relates to the technical field of charging, and particularly to a voltage stabilization and current sharing control method and device for a three-phase interleaved LLC converter. Background Art

[0002] Since the power of the current charging module is getting higher and higher, it has increased from the previous single-module 20kW to the current 30kW, 40kW or even 60kW. In order to increase the power and reduce the cost, the DCDC part in the charging module is usually two to three LLC converters in parallel. Due to hardware differences, when the output voltages are paralleled, large voltage ripples will be generated, and current sharing may not be achieved at the same time. One converter may output at full load or even overload, while the other outputs at light load. Therefore, it is necessary to better control the output voltage of the module to reduce the output ripple and achieve current sharing.

[0003] The prior art needs to use current sampling for voltage droop control for parallel connection. Since the droop control is sensitive to the accuracy of the output current, it is necessary to add a current sampling, and at the same time, the parallel competition frequency is not fixed, resulting in a large ripple problem. Summary of the Invention

[0004] Based on this, in view of the above technical problems, it is necessary to provide a voltage stabilization and current sharing control method and device for a three-phase interleaved LLC converter.

[0005] In a first aspect, an embodiment of the present application provides a voltage stabilization and current sharing control method for a three-phase interleaved LLC converter. The three-phase interleaved LLC converter includes a plurality of parallel three-phase interleaved LLC circuits. The method includes:

[0006] Real-time obtain the output voltage and output current of each three-phase interleaved LLC circuit;

[0007] For each three-phase interleaved LLC circuit, based on a given reference voltage, an injection signal, and the output voltage, use a voltage loop to determine the currently output reference current; wherein, the phase differences of the injection signals of each three-phase interleaved LLC circuit are fixed values, and the sum of the phase differences is 360°; and

[0008] Based on the currently obtained reference current and the output current, use a current loop to determine the currently output switching frequency;

[0009] Based on each switching frequency, regulate the output voltage and output current of the three-phase interleaved LLC converter.

[0010] In one of the embodiments, the step of for each three-phase interleaved LLC circuit, based on a given reference voltage, an injection signal, and the output voltage, using a voltage loop to determine the currently output reference current includes:

[0011] Subtract the output voltage from the sum of the given reference voltage and the injection signal to obtain a voltage deviation.

[0012] Input the voltage deviation into a voltage loop controller, and after modulation, output the current reference current.

[0013] In one embodiment, for each of the three-phase interleaved LLC circuits, determining the current reference current output based on a given reference voltage, an injection signal, and the output voltage using a voltage loop includes:

[0014] Subtract the output voltage from the given reference voltage and then add the injection signal to obtain a voltage deviation.

[0015] Input the voltage deviation into a voltage loop controller, and after modulation, output the current reference current.

[0016] In one embodiment, based on the current reference current and the output current, determining the current switching frequency output using a current loop includes:

[0017] Subtract the output current from the current reference current to obtain a current deviation.

[0018] Input the current deviation into a current loop controller, and after modulation, output the current switching frequency.

[0019] In one embodiment, each of the three-phase interleaved LLC circuits includes a plurality of driving switches. Based on each of the switching frequencies, regulating the output voltage and output current of the three-phase interleaved LLC converter includes:

[0020] Generate driving signals for each of the driving switches based on each of the switching frequencies;

[0021] Drive the corresponding driving switches based on each of the driving signals to regulate the output voltage and output current of the three-phase interleaved LLC converter.

[0022] In one embodiment, the injection signal is a sine wave signal, and the amplitude of the injection signal is determined based on the error between the given reference voltage and the output voltage of the three-phase interleaved LLC converter.

[0023] In one embodiment, the three-phase interleaved LLC converter includes two parallel three-phase interleaved LLC circuits, and the phases of the injection signals of each of the three-phase interleaved LLC circuits are staggered by 180°.

[0024] In one embodiment, the three-phase interleaved LLC converter includes three three-phase interleaved LLC circuits connected in parallel, and the phases of the injection signals of each of the three-phase interleaved LLC circuits are interleaved by 120° with respect to each other.

[0025] In a second aspect, an embodiment of the present application further provides a voltage-stabilizing and current-sharing control device for a three-phase interleaved LLC converter. The device includes:

[0026] An acquisition module, configured to acquire the output voltage and output current of each of the three-phase interleaved LLC circuits in real time;

[0027] A determination module, configured to, for each of the three-phase interleaved LLC circuits, based on a given reference voltage, an injection signal, and the output voltage, determine a currently output reference current through a voltage loop; wherein, the phase differences of the injection signals of each of the three-phase interleaved LLC circuits are fixed values, and the sum of the phase differences is 360°; and based on the currently determined reference current and the output current, determine a currently output switching frequency through a current loop;

[0028] A regulation module, configured to regulate the output voltage and output current of the three-phase interleaved LLC circuits based on each of the switching frequencies.

[0029] In a third aspect, an embodiment of the present application further provides a three-phase interleaved parallel LLC converter, including a plurality of three-phase interleaved LLC circuits connected in parallel and the voltage-stabilizing and current-sharing control device as described in the second aspect above. The voltage-stabilizing and current-sharing control device is connected to the plurality of three-phase interleaved LLC circuits connected in parallel, and is configured to perform voltage-stabilizing and current-sharing control on the three-phase interleaved parallel LLC converter.

[0030] The above voltage-stabilizing and current-sharing control method and device for a three-phase interleaved LLC converter acquire the output voltage and output current of each of the three-phase interleaved LLC circuits in real time. For each of the three-phase interleaved LLC circuits, based on a given reference voltage, an injection signal, and the output voltage, determine a currently output reference current through a voltage loop; and based on the currently determined reference current and the output current, determine a currently output switching frequency through a current loop; and regulate the output voltage and output current of the three-phase interleaved LLC converter based on each of the switching frequencies. Wherein, the phase differences of the injection signals of each of the three-phase interleaved LLC circuits are fixed values, and the sum of the phase differences is 360°. The present application actively superimposes an injection signal on the voltage loop, and actively distributes power to reduce the output voltage ripple and achieve current sharing.

[0031] Details of one or more embodiments of the present application are set forth in the following drawings and description to make other features, objects, and advantages of the present application more concise and understandable. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The accompanying drawings described herein are used to provide a further understanding of the present application and form a part of the present application. The schematic embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation of the present application. In the drawings:

[0033] Figure 1 is the circuit diagram of a three-phase interleaved LLC converter in an embodiment;

[0034] Figure 2 is the schematic flowchart of the voltage stabilization and current sharing control method for a three-phase interleaved LLC converter in an embodiment;

[0035] Figure 3 is the schematic diagram of the PI controller regulation in the voltage stabilization and current sharing control method in an embodiment;

[0036] Figure 4 is the example diagram of the effect of voltage stabilization and current sharing control in an embodiment;

[0037] Figure 5 is the example diagram of the effect of voltage stabilization and current sharing control in another embodiment;

[0038] Figure 6 is the structural diagram of the voltage stabilization and current sharing control device for a three-phase interleaved LLC converter in an embodiment. Detailed Embodiments

[0039] In order to make the objectives, technical solutions and advantages of the present application clearer, the present application will be described and explained below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application. Based on the embodiments provided by the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the scope of protection of the present application.

[0040] Obviously, the accompanying drawings in the following description are only some examples or embodiments of the present application. For those of ordinary skill in the art, without creative efforts, the present application can also be applied to other similar scenarios based on these drawings. In addition, it can also be understood that although the efforts made in this development process may be complex and lengthy, for those of ordinary skill in the art related to the content disclosed in the present application, some design, manufacturing or production changes based on the technical content disclosed in the present application are only conventional technical means and should not be understood that the content disclosed in the present application is insufficient.

[0041] References to "embodiments" in this application mean that specific features, structures, or characteristics described in connection with the embodiments can be included in at least one embodiment of this application. The phrase appears in various places in the specification and does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. It is explicitly and implicitly understood by those of ordinary skill in the art that the embodiments described in this application can be combined with other embodiments without conflict.

[0042] Unless otherwise defined, the technical terms or scientific terms involved in this application shall have the ordinary meaning understood by those of ordinary skill in the technical field to which this application belongs. The words "a", "an", "one kind", "the" and the like involved in this application do not indicate a limitation in quantity and can represent a singular or plural number. The terms "include", "comprise", "have" and any variations thereof involved in this application are intended to cover non-exclusive inclusion; for example, a process, method, system, product or device that includes a series of steps or modules (units) is not limited to the listed steps or units, but may further include unlisted steps or units, or may further include other steps or units inherent to these processes, methods, products or devices. The terms "connected", "coupled" and the like involved in this application are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. The term "plurality" involved in this application means two or more. "And / or" describes the association relationship of associated objects and indicates that three relationships may exist. For example, "A and / or B" may represent: A exists alone, A and B exist simultaneously, and B exists alone. The character " / " generally represents an "or" relationship between the associated objects before and after. The terms "first", "second", "third", etc. involved in this application are only used to distinguish similar objects and do not represent a specific order for the objects.

[0043] An embodiment of this application provides a voltage stabilization and current sharing control method for a three-phase interleaved LLC converter, as Figure 1 shown in the circuit diagram of the three-phase interleaved LLC converter. The three-phase interleaved LLC converter includes a plurality of three-phase interleaved LLC circuits connected in parallel. Each of the three-phase interleaved LLC circuits includes a plurality of driving switches, as Figure 2 shown. The method includes the following steps:

[0044] Step 201, obtain the output voltage and output current of each of the three-phase interleaved LLC circuits in real time.

[0045] Specifically, the voltage Vout and output current Iout output by each three-phase interleaved LLC circuit are collected in real time through sensors.

[0046] Step 202: For each of the three-phase interleaved LLC circuits, based on the given reference voltage, injection signal, and the output voltage, use the voltage loop to determine the currently output reference current; and based on the current reference current and the output current, use the current loop to determine the currently output switching frequency.

[0047] Specifically, for each three-phase interleaved LLC circuit, according to the given reference voltage Vout_ref, injection signal, and output voltage Vout, use the voltage loop to determine the currently output reference current Iout_ref, and input the reference current Iout_ref and the output current Iout into the current loop to use the current loop to determine the currently output switching frequency.

[0048] Among them, the injection signal can be a sine wave signal or a cosine wave signal. The phase differences between the injection signals corresponding to the three-phase interleaved LLC circuits are fixed values, and the sum of the phase differences is one cycle of 360 degrees. For example, when two three-phase interleaved LLC circuits are connected in parallel in a three-phase interleaved LLC converter, the phase differences of the injection signals corresponding to the three-phase interleaved LLC circuits are staggered by 180 degrees. When three three-phase interleaved LLC circuits are connected in parallel in a three-phase interleaved LLC converter, the phase differences of the injection signals corresponding to the three-phase interleaved LLC circuits are staggered by 120 degrees in sequence. For example, when the injection signal is a sine wave signal, its injection amount is expressed as Asin(wt), where A is the amplitude of the injected sine wave, w is the angular velocity of the injected sine wave, and w = 2π×f (f is the frequency of the injected sine wave). Among them, the amplitude of the injection signal is determined by the error between the output voltage and the reference voltage of the three-phase interleaved LLC converter. Exemplarily, the error between the output voltage and the reference voltage of the three-phase interleaved LLC converter is between -1V and 1V, and the amplitude A can be set to 1. Since the switching frequency of the LLC converter is relatively high, the frequency f of the injected sine wave is relatively large. For example, the sine wave frequency f is taken as 1000HZ.

[0049] Step 203: Based on each of the switching frequencies, regulate the output voltage and output current of the three-phase interleaved LLC converter.

[0050] In the above steps 201 to 203, by obtaining the output voltage and output current of each of the three-phase interleaved LLC circuits in real time, for each of the three-phase interleaved LLC circuits, based on a given reference voltage, an injection signal, and the output voltage, a reference current for the current output is determined using a voltage loop; and based on the current reference current and the output current, a switching frequency for the current output is determined using a current loop; based on each of the switching frequencies, the output voltage and output current of the three-phase interleaved LLC converter are regulated, wherein the phase differences of the injection signals of each of the three-phase interleaved LLC circuits are fixed values, and the sum of the phase differences is 360°. In the present application, by actively injecting high-frequency sine / cosine signals, power is actively distributed to reduce the output voltage ripple and keep the frequency fixed, and the effect of current sharing is achieved.

[0051] In one embodiment, for each of the three-phase interleaved LLC circuits, determining the reference current for the current output using a voltage loop based on a given reference voltage, an injection signal, and the output voltage includes the following steps:

[0052] Step 301: Subtract the output voltage from the sum of the given reference voltage and the injection signal to obtain a voltage deviation.

[0053] Step 302: Input the voltage deviation into a voltage loop controller, and after modulation, output the current reference current.

[0054] In one embodiment, for each of the three-phase interleaved LLC circuits, determining the reference current for the current output using a voltage loop based on a given reference voltage, an injection signal, and the output voltage includes the following steps:

[0055] Step 401: Add the injection signal to the difference between the given reference voltage and the output voltage to obtain a voltage deviation.

[0056] Step 402: Input the voltage deviation into a voltage loop controller, and after modulation, output the current reference current.

[0057] In the present application, the injection signal can be injected from the reference voltage Vout_ref through Step 301, or can be injected from the output voltage Vout through Step 401.

[0058] In one embodiment, the determining the switching frequency for the current output using a current loop based on the current reference current and the output current includes the following: Subtract the output current from the current reference current to obtain a current deviation; input the current deviation into a current loop controller, and after modulation, output the current switching frequency.

[0059] In an exemplary embodiment, the three-phase interleaved LLC converter includes two three-phase interleaved LLC circuits connected in parallel, hereinafter simply referred to as Module A and Module B, and its control process is as follows: Figure 3 as shown.

[0060] For Module A, the given reference voltage Vout1_ref is superimposed on the injection signal -Asin(wt) and then subtracted from the output voltage Vout1 to obtain a voltage deviation. Vout1 is the sampled output voltage of Module A, Vout1 = (Uout1+)-(Uout1-). The voltage deviation is input into the voltage-loop PI controller, and after modulation, the reference current Iout1_ref is output. The reference current Iout1_ref is subtracted from the output current Iout1 to obtain a current deviation, and the current deviation is input into the current-loop PI controller. After modulation, the switching frequency Period1 is output, which is the switching frequency for driving switches S1 - S6. Among them, S1 and S2 are complementary and frequency-varying outputs with a duty cycle of 50%, S3 and S4 are complementary and frequency-varying outputs with a duty cycle of 50%, the output of S3 and S1 is staggered by 120°, S5 and S6 are complementary and frequency-varying outputs with a duty cycle of 50%, and the output of S5 and S1 is staggered by 240°.

[0061] For Module B, the given reference voltage Vout2_ref is superimposed on the injection signal +Asin(wt) and then subtracted from the output voltage Vout2 to obtain a voltage deviation. Vout2 is the sampled output voltage of Module B, Vout2 = (Uout2+)-(Uout2-). The voltage deviation is input into the voltage-loop PI controller, and after modulation, the reference current Iout2_ref is output. The reference current Iout2_ref is subtracted from the output current Iout2 to obtain a current deviation, and the current deviation is input into the current-loop PI controller. After modulation, the switching frequency Period2 is output, which is the switching frequency of S7 - S12. Among them, S7 and S8 are complementary and frequency-varying outputs with a duty cycle of 50%, S9 and S10 are complementary and frequency-varying outputs with a duty cycle of 50%, the output of S9 and S7 is staggered by 120°, S11 and S12 are complementary and frequency-varying outputs with a duty cycle of 50%, and the output of S11 and S7 is staggered by 240°.

[0062] Among them: the injection signal Asin(wt) = 1×sin(2×pi×500);

[0063] Vout1_ref is the reference value of the output voltage of Module A;

[0064] Vout1 is the sampled value of the output voltage of Module A, Vout1 = (Uout1+)-(Uout1-);

[0065] PI is a proportional-integral controller;

[0066] Iout1_ref is the value output by Module A after passing through a proportional-integral controller;

[0067] Iout1 is the sampled value of the output current of Module A;

[0068] Period1 is the control quantity finally output by the PI controller to Module A (i.e., the switching frequency of switches S1–S6);

[0069] Switches S1 - S6 are all switched at the frequency of period1;

[0070] Vout2_ref is the reference value of the output voltage of Module B;

[0071] Vout2 is the sampled value of the output voltage of Module B, Vout2 = (Uout2+) - (Uout2-);

[0072] PI is a proportional-integral controller;

[0073] Iout2_ref is the value output by Module B after passing through a proportional-integral controller;

[0074] Iout2 is the sampled value of the output current of Module B;

[0075] Period2 is the control quantity finally output by the PI controller to Module B (i.e., the switching frequency of switches S7–S12);

[0076] Switches S7 - S12 are all switched at the frequency of period2.

[0077] By setting the amplitude value A and the w value, a more appropriate ripple voltage and current sharing effect can be obtained, as Figure 4 and Figure 5 shown, Figure 4 is the effect diagram with amplitude A = 1 and frequency = 100Hz, Figure 5 is the effect diagram with amplitude A = 1 and frequency = 500Hz.

[0078] Among them, the voltages Uout1+ and Uout2+ are connected together, and Uout1- and Uout2- are connected together. Module A and Module B are connected in parallel for output. When the voltages are connected in parallel, the load will draw energy from the module with the higher voltage. Assuming that the voltage Vout1 output by Module A is higher than the Vout2 output by Module B, then the load will draw energy from Module A. In order to make the output powers of Module A and Module B the same, injecting Asin(wt) is to actively make the output voltage Vout1 of Module A higher than the output voltage Vout2 of Module B. After half a cycle, that is, 0.5×(1 / f), make the output voltage Vout2 of Module B higher than Vout1, so that Module A and Module B take turns to output and the output powers are the same within the f cycle.

[0079] Since the injected signal is a sine transformation, the parallel part will alternately supply energy to the load. Assuming the switching frequency is 1 Hz, in the first half cycle of 0.5 s, Module A supplies energy to the load, and in the other half cycle of 0.5 s, Module B supplies energy. When the load is fixed, the two modules output the same power and current within one cycle of 1 s.

[0080] In this application, by injecting a high-frequency component into the voltage loop, the output voltage ripple of the parallel modules is reduced and the current sharing purpose is achieved.

[0081] In one of the embodiments, each of the three-phase interleaved LLC circuits includes a plurality of driving switches. Based on each of the switching frequencies, regulating the output voltage and output current of the three-phase interleaved LLC converter includes the following steps:

[0082] Step 501, generating driving signals for each of the driving switches based on each of the switching frequencies.

[0083] Step 502, driving the corresponding driving switches based on each of the driving signals to regulate the output voltage and output current of the three-phase interleaved LLC converter.

[0084] In one embodiment, as Figure 6 shown, a voltage stabilization and current sharing control device for a three-phase interleaved LLC converter is provided. The device includes: an acquisition module 10 for real-time acquiring the output voltage and output current of each of the three-phase interleaved LLC circuits. A determination module 20 for, for each of the three-phase interleaved LLC circuits, determining a current reference output currently based on a given reference voltage, an injection signal, and the output voltage in a voltage loop; wherein, the phase differences of the injection signals of each of the three-phase interleaved LLC circuits are fixed values, and the sum of the phase differences is 360°; and determining a switching frequency output currently based on the current reference current and the output current in a current loop. A regulation module 30 for regulating the output voltage and output current of the three-phase interleaved LLC circuit based on each of the switching frequencies.

[0085] In one embodiment, a three-phase interleaved parallel LLC converter is provided, including a plurality of three-phase interleaved LLC circuits connected in parallel and the voltage stabilization and current sharing control device as described in the above embodiment. The voltage stabilization and current sharing control device is connected to the plurality of three-phase interleaved LLC circuits connected in parallel for performing voltage stabilization and current sharing control on the three-phase interleaved parallel LLC converter.

[0086] The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity of description, 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, it should be considered as the scope described in this specification.

[0087] The embodiments described above merely represent several implementation manners of the present application. The description thereof is relatively specific and detailed, but it should not be construed as a limitation to the scope of the invention patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several modifications and improvements can still be made, and these all fall within the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the appended claims.

Claims

1. A voltage stabilization and current sharing control method for a three-phase interleaved LLC converter, the three-phase interleaved LLC converter comprising a plurality of three-phase interleaved LLC circuits connected in parallel, characterized in that, The method includes: Obtaining the output voltage and output current of each of the three-phase interleaved LLC circuits in real time; For each of the three-phase interleaved LLC circuits, based on a given reference voltage, an injection signal, and the output voltage, determining a reference current of the current output using a voltage loop; wherein, the phase difference of the injection signals of each of the three-phase interleaved LLC circuits is a fixed value, and the sum of the phase differences is 360°; and Based on the current reference current and the output current, determining the switching frequency of the current output using a current loop; Based on each of the switching frequencies, regulating the output voltage and output current of the three-phase interleaved LLC converter.

2. The method according to claim 1, wherein The step of, for each of the three-phase interleaved LLC circuits, determining the reference current of the current output using a voltage loop based on a given reference voltage, an injection signal, and the output voltage includes: Subtracting the output voltage from the sum of the given reference voltage and the injection signal to obtain a voltage deviation; Inputting the voltage deviation into a voltage loop controller, and modulating to output the current reference current.

3. The method according to claim 1, wherein The step of, for each of the three-phase interleaved LLC circuits, determining the reference current of the current output using a voltage loop based on a given reference voltage, an injection signal, and the output voltage includes: Adding the injection signal to the difference between the given reference voltage and the output voltage to obtain a voltage deviation; Inputting the voltage deviation into a voltage loop controller, and modulating to output the current reference current.

4. The method according to claim 1, characterized in that, The step of, based on the current reference current and the output current, determining the switching frequency of the current output using a current loop includes: Subtracting the output current from the current reference current to obtain a current deviation; Inputting the current deviation into a current loop controller, and modulating to output the current switching frequency.

5. The method according to claim 4, characterized in that Each of the three-phase interleaved LLC circuits includes a plurality of driving switches, and the step of, based on each of the switching frequencies, regulating the output voltage and output current of the three-phase interleaved LLC converter includes: Generating driving signals for each of the driving switches based on each of the switching frequencies; Driving the corresponding driving switches based on each of the driving signals to regulate the output voltage and output current of the three-phase interleaved LLC converter.

6. The method according to claim 1, wherein The injection signal is a sine wave signal, and the amplitude of the injection signal is determined based on the error between the given reference voltage and the output voltage of the three-phase interleaved LLC converter.

7. The method according to claim 1, wherein The three-phase interleaved LLC converter includes two three-phase interleaved LLC circuits connected in parallel, and the phases of the injection signals of each of the three-phase interleaved LLC circuits are staggered by 180° from each other.

8. The method according to claim 1, wherein The three-phase interleaved LLC converter includes three three-phase interleaved LLC circuits connected in parallel, and the phases of the injection signals of each of the three-phase interleaved LLC circuits are staggered by 120° from each other.

9. A voltage stabilizing and current sharing control device for a three-phase interleaved LLC converter, characterized in that, The device includes: An acquisition module, configured to obtain the output voltage and output current of each of the three-phase interleaved LLC circuits in real time; A determination module, configured to, for each of the three-phase interleaved LLC circuits, determine a reference current of the current output based on a given reference voltage, an injection signal, and the output voltage; wherein a phase difference of the injection signals of the three-phase interleaved LLC circuits is a fixed value, and a sum of the phase differences is 360°; and determine a switching frequency of the current output based on the current reference current and the output current by means of a current loop; A regulation module, configured to regulate an output voltage and an output current of the three-phase interleaved LLC circuit based on the switching frequencies.

10. A three-phase interleaved parallel LLC converter, characterized in that The three-phase interleaved parallel LLC converter includes a plurality of three-phase interleaved LLC circuits connected in parallel and the voltage stabilization and current sharing control device according to claim 8, wherein the voltage stabilization and current sharing control device is connected to the plurality of three-phase interleaved LLC circuits connected in parallel and is configured to perform voltage stabilization and current sharing control on the three-phase interleaved parallel LLC converter.

Images