Three-phase resonant conversion circuit, its control method, and electronic device

Abstract

The present application discloses a three-phase resonant conversion circuit, its control method, and an electronic device. The control method of the three-phase resonant conversion circuit includes: obtaining the output current and / or output voltage of a three-phase resonant output circuit; generating a three-phase drive control signal or a two-phase drive control signal based on a first comparison result between the output current and the two-phase maximum output currents and / or a second comparison result between the output voltage and the two-phase maximum output voltages; and using the three-phase drive control signal or the two-phase drive control signal to adjust the switching states of a three-phase switch circuit so as to adjust the output voltage or the output current. By the above method, the control method of the three-phase resonant conversion circuit of the present application realizes flexible switching between two-phase and three-phase wave generation modes in response to changes in the output current and / or output voltage, so as to ensure the efficiency at light load and no load, the stability of the output voltage and its DC gain curve state, and take into account the advantages of three-phase interleaved parallel connection under heavy load or when high output power is required.

Description

Technical Field

[0001] The present application relates to the technical field of circuit control, and particularly to a three-phase resonant conversion circuit, a control method thereof, and an electronic device. Background Art

[0002] A three-phase LLC (including an additional inductor (L, inductance), which is connected in series with the other two components, the inductor L and the capacitor (C, capacitor), thus named L-L-C converter) resonant converter has significant advantages in reducing the output current ripple and expanding the output power capacity.

[0003] However, at light load and no load, the higher switching frequency in the three-phase LLC resonant converter is not conducive to improving efficiency, and at light load, the discharge process of the parasitic capacitor after being charged has a particularly large impact on the output of the resonant converter, which will change the state of the DC gain curve and cause the output voltage to get out of control. Summary of the Invention

[0004] The main technical problem to be solved by the present application is to provide a three-phase resonant conversion circuit, a control method thereof, and an electronic device, which can solve the problems that the three-phase LLC resonant converter in the prior art is not conducive to improving efficiency at light load and no load, and at light load, it will change the state of the DC gain curve and cause the output voltage to get out of control.

[0005] To solve the above technical problem, a technical solution adopted by the present application is: to provide a control method for a three-phase resonant conversion circuit. The three-phase resonant conversion circuit includes a three-phase switch circuit and a three-phase resonant output circuit. The three-phase switch circuit is coupled to the three-phase resonant output circuit and is used to be coupled to a power supply circuit. Wherein, the control method of the three-phase resonant conversion circuit includes: obtaining the output current and / or output voltage of the three-phase resonant output circuit; generating a three-phase drive control signal or a two-phase drive control signal based on a first comparison result between the output current and the maximum output current of two phases and / or a second comparison result between the output voltage and the maximum output voltage of two phases; using the three-phase drive control signal or the two-phase drive control signal to adjust the switching state of the three-phase switch circuit so as to adjust the output voltage or output current.

[0006] Among them, the steps of generating a three-phase drive control signal or a two-phase drive control signal based on a first comparison result between an output current and a two-phase maximum operating voltage and / or a second comparison result between an output voltage and a two-phase maximum output voltage include: detecting whether the output current is greater than a two-phase maximum output current; if the output current is greater than the two-phase maximum output current, generating a three-phase drive control signal by using the output current or the output voltage; among them, the three-phase switch circuit includes a first-phase switch sub-circuit, a second-phase switch sub-circuit, and a third-phase switch sub-circuit that are phase-coupled, and the first-phase switch sub-circuit, the second-phase switch sub-circuit, and the third-phase switch sub-circuit are coupled to a three-phase resonant output circuit and are used to be coupled to a power supply circuit; the three-phase drive control signal includes a first drive signal, a second drive signal, and a third drive signal; the steps of adjusting the switching state of the three-phase switch circuit by using the three-phase drive control signal or the two-phase drive control signal to adjust the output voltage or the output current include: respectively sending the first drive signal, the second drive signal, and the third drive signal to the first-phase switch sub-circuit, the second-phase switch sub-circuit, and the third-phase switch sub-circuit to respectively adjust the switching states of the first-phase switch sub-circuit, the second-phase switch sub-circuit, and the third-phase switch sub-circuit, so as to adjust the output voltage or the output current.

[0007] Among them, the control method of the three-phase resonant conversion circuit further includes: if the output current is not greater than the two-phase maximum output current, detecting whether the output voltage is greater than the two-phase maximum output voltage; if the output voltage is not greater than the two-phase maximum output voltage, detecting whether the frequency of a pre-transmission drive signal generated by using the output current or the output voltage is greater than a three-phase maximum wave generation frequency; if the frequency of the pre-transmission drive signal is greater than the three-phase maximum wave generation frequency, generating a two-phase drive control signal by using the current output current or output voltage; among them, the two-phase drive control signal includes a first control signal and a second control signal; the steps of adjusting the switching state of the three-phase switch circuit by using the three-phase drive control signal or the two-phase drive control signal to adjust the output voltage or the output current include: respectively sending the first control signal and the second control signal to any two of the first-phase switch sub-circuit, the second-phase switch sub-circuit, and the third-phase switch sub-circuit to respectively adjust the switching states of any two of the first-phase switch sub-circuit, the second-phase switch sub-circuit, and the third-phase switch sub-circuit, so as to adjust the output voltage or the output current.

[0008] Among them, the control method of the three-phase resonant conversion circuit further includes: if the frequency of the pre-transmission drive signal is not greater than the three-phase maximum wave generation frequency, detecting whether the frequency of the pre-transmission drive signal is less than a two-phase minimum wave generation frequency; if the frequency of the pre-transmission drive signal is less than the two-phase minimum wave generation frequency, generating a three-phase drive control signal by using the current output current or output voltage.

[0009] Among them, the control method of the three-phase resonant conversion circuit further includes: detecting whether a three-phase drive control signal or a two-phase drive control signal is currently generated; if a three-phase drive control signal is currently generated, detecting whether the frequency of the pre-transmitted drive signal is greater than the three-phase maximum wave generation frequency; if the frequency of the pre-transmitted drive signal is greater than the three-phase maximum wave generation frequency, adjusting the pulse width of the three-phase drive control signal by using the output current or the output voltage.

[0010] Among them, after the step of adjusting the duty cycle of the three-phase drive control signal by using the output voltage, it further includes: detecting whether the pulse width of the adjusted three-phase drive control signal is less than the minimum pulse width; if the pulse width of the adjusted three-phase drive control signal is less than the minimum pulse width, performing on-off adjustment on the three-phase drive control signal.

[0011] Among them, the control method of the three-phase resonant conversion circuit further includes: detecting whether a three-phase drive control signal or a two-phase drive control signal is currently generated; if the frequency of the pre-transmitted drive signal is not greater than the three-phase maximum wave generation frequency, adjusting the signal frequency of the three-phase drive control signal by using the output current or the output voltage.

[0012] Among them, the control method of the three-phase resonant conversion circuit further includes: if a two-phase drive control signal is currently generated, detecting whether the frequency of the pre-transmitted drive signal is greater than the two-phase maximum wave generation frequency; if the frequency of the pre-transmitted drive signal is not greater than the two-phase maximum wave generation frequency, adjusting the phase difference between the first control signal and the second control signal.

[0013] Among them, after the step of adjusting the phase difference between the first control signal and the second control signal, it further includes: detecting whether the phase difference between the adjusted first control signal and the second control signal is less than the minimum phase difference; if the phase difference between the adjusted first control signal and the second control signal is less than the minimum phase difference, performing on-off adjustment on the first control signal and the second control signal.

[0014] Among them, the control method of the three-phase resonant conversion circuit further includes: if the frequency of the pre-transmitted drive signal is less than the two-phase maximum wave generation frequency, adjusting the signal frequency of the two-phase drive control signal by using the output current or the output voltage.

[0015] Among them, before the step of detecting whether the output current is greater than the two-phase maximum output current, it further includes: detecting whether it is the first power-on; if it is currently the first power-on, generating a two-phase drive control signal by using the output current or the output voltage.

[0016] To solve the above technical problems, another technical solution adopted in this application is: to provide a three-phase resonant conversion circuit, wherein the three-phase resonant conversion circuit includes a three-phase switch circuit, a three-phase resonant output circuit, and a control circuit. The three-phase switch circuit is coupled to the three-phase resonant output circuit and is used to be coupled to a power supply circuit. The control circuit is coupled to the three-phase switch circuit and the three-phase resonant output circuit; wherein, the control circuit is used to control the three-phase switch circuit by adopting the control method of the three-phase resonant conversion circuit described in any one of the above.

[0017] To solve the above technical problems, yet another technical solution adopted in this application is: to provide an electronic device, wherein the electronic device includes a housing and a three-phase resonant conversion circuit connected to the housing; wherein, the three-phase resonant conversion circuit is the three-phase resonant conversion circuit described above.

[0018] The beneficial effects of this application are as follows: Different from the prior art, the control method of the three-phase resonant conversion circuit provided in this application obtains the output current and / or output voltage of the three-phase resonant output circuit, and generates a three-phase drive control signal or a two-phase drive control signal based on the first comparison result between the output current and the two-phase maximum output current and / or the second comparison result between the output voltage and the two-phase maximum output voltage, and uses the three-phase drive control signal or the two-phase drive control signal to adjust the switching state of the three-phase switch circuit to adjust the output voltage or output current. Therefore, it can flexibly switch between the two-phase wave generation mode and the three-phase wave generation mode in response to the changes in the magnitudes of the output current and output voltage. When the load is light or no load, the three-phase switch circuit is controlled to work in the two-phase full-bridge mode. At this time, it is equivalent to only two bridge arms of the three-phase switch circuit working alternately to achieve two-phase wave generation, so as to ensure the stability of the output voltage and its DC gain curve state, which helps to improve the efficiency and stability of the three-phase resonant conversion circuit when the load is light; and in the case of heavy load or high output power required, it can also work in the three-phase interleaved parallel mode to make full use of the advantages of three-phase interleaved parallel. Description of the Drawings

[0019] To more clearly illustrate the technical solutions in the embodiments of this application, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of this application. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings, where:

[0020] Figure 1 is a schematic flowchart of the first embodiment of the control method of the three-phase resonant conversion circuit of this application;

[0021] Figure 2 is a schematic structural diagram of the first embodiment of the three-phase resonant output circuit of this application;

[0022] Figure 3 It is a schematic flowchart of the second implementation manner of the control method for the three-phase resonant conversion circuit of the present application;

[0023] Figure 4 It is a schematic structural diagram of a specific embodiment of the three-phase resonant output circuit of the present application;

[0024] Figure 5 It is a schematic structural diagram of an implementation manner of an electronic device of the present application. Specific implementation manner

[0025] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present application.

[0026] The terms "first", "second", and "third" in the present application are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first", "second", and "third" may explicitly or implicitly include at least one of such features. In the description of the present application, the meaning of "a plurality" is at least two, such as two, three, etc., unless otherwise specifically defined. All directional indications (such as up, down, left, right, front, back...) in the embodiments of the present application are only used to explain the relative positional relationship and movement conditions between components in a specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indications will also change accordingly. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units is not limited to the listed steps or units, but optionally further includes steps or units not listed, or optionally further includes other steps or units inherent to these processes, methods, products, or devices.

[0027] Referring to "embodiment" herein means that a specific feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the present application. The phrase appearing in various positions in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. Those skilled in the art will explicitly and implicitly understand that the embodiments described herein may be combined with other embodiments.

[0028] Next, the present application will be described in detail in conjunction with the accompanying drawings and embodiments.

[0029] Please refer to Figure 1 and Figure 2 , where Figure 1 is a schematic flowchart of the first embodiment of the control method of the three-phase resonant conversion circuit of the present application, Figure 2 is a schematic structural diagram of the first embodiment of the three-phase resonant conversion circuit of the present application. Specifically, the following steps may be included:

[0030] S11: Obtain the output current and / or output voltage of the three-phase resonant output circuit.

[0031] It can be understood that the control method of the first three-phase resonant conversion circuit 20 in this embodiment is specifically applied to the first three-phase resonant conversion circuit 20 as shown in Figure 2 . The first three-phase resonant conversion circuit 20 includes a first three-phase switch circuit 21 and a first three-phase resonant output circuit 22. The first three-phase switch circuit 21 is coupled to the first three-phase resonant output circuit 22 and is used to be coupled to the power supply circuit 101. The first three-phase resonant output circuit 22 is also used to be coupled to the signal function circuit; wherein, the first control circuit 23 is coupled to the first three-phase switch circuit 21 and the first three-phase resonant output circuit 22 to control the first three-phase switch circuit 21 by using the control method of the first three-phase resonant conversion circuit 20 described in any item herein.

[0032] It should be noted that the power supply circuit 101 may specifically be a battery with a DC output, a DC voltage regulator, a photovoltaic power supply, a storage power supply, or any reasonable DC or AC power supply such as grid power supply, photovoltaic power supply, or independent generator. It may also be a power supply adjustment circuit that receives and performs power conversion and adjustment on a battery, a DC voltage regulator, a photovoltaic power supply, a storage power supply, a grid power supply, a photovoltaic power supply, an independent generator, or any other reasonable upper-level power supply to obtain a DC or AC power supply output. This embodiment does not limit this.

[0033] The signal function circuit can be understood as a load circuit that operates using the power supply output of the first three-phase resonant conversion circuit 20, or can also be understood as the backend function circuit of the first three-phase resonant conversion circuit 20, aiming to achieve any reasonable signal function.

[0034] In addition, "coupled" in this article refers to including any direct and indirect connection means. Therefore, if it is described in the text that the first circuit is coupled to the second circuit, it means that the first circuit can be directly connected to the second circuit through electrical connection, wireless transmission, optical transmission, or other signal connection means, or can be indirectly electrically connected or signal-connected to the second circuit through other circuits or connection means.

[0035] Specifically, the first control circuit 23 is configured to sample and obtain the output current and / or output voltage output from the first three-phase resonant output circuit 22 to the subsequent signal function circuit.

[0036] S12: Generate a three-phase drive control signal or a two-phase drive control signal based on the first comparison result between the output current and the two-phase maximum output current and / or the second comparison result between the output voltage and the two-phase maximum output voltage.

[0037] The first control circuit 23 compares the currently obtained output current with the two-phase maximum output current to obtain a first comparison result, that is, detects whether the currently obtained output current is greater than the two-phase maximum output current, and / or compares the currently obtained output voltage with the two-phase maximum output voltage to obtain a second comparison result, that is, detects whether the currently obtained output voltage is greater than the two-phase maximum output voltage.

[0038] Among them, the first control circuit 23 is further configured to determine the current control mode according to the first comparison result and / or the second comparison result, that is, adopt a three-phase wave generation mode or a two-phase wave generation mode. For example, when it is determined that the currently obtained output current is greater than the two-phase maximum output current, the three-phase wave generation mode is adopted; when it is determined that the currently obtained output current is not greater than the two-phase maximum output current and the currently obtained output voltage is not greater than the two-phase maximum output voltage, the two-phase wave generation mode is adopted, etc., so as to be able to reasonably select the three-phase wave generation mode or the two-phase wave generation mode in response to the first comparison result and / or the second comparison result, and / or any other reasonable judgment adjustment. The present application does not make a limitation on this.

[0039] It should be noted that the two-phase maximum output current can be specifically obtained by measuring the current ripple acceptable on the input side of the first three-phase resonant conversion circuit 20 and reasonably setting and adjusting the measurement result; the two-phase maximum output voltage can be specifically obtained by measuring the voltage required for the normal operation of the first three-phase resonant conversion circuit 20 under light load and the hard-switching physical characteristics of each switching tube in the first three-phase switch circuit 21, and reasonably setting and adjusting the measurement result.

[0040] In addition, light load refers to a common load state of an electronic circuit. The load states usually include: no load, light load, full load, and overload. Among them, light load is relative to full load, which means that within the load range of the circuit, the load rate is below 30%. Of course, it can also be considered that a load below 50% is a light load, and there is no strict definition. As for whether a light load means a large load resistance is not certain. In the load of a constant current source, a smaller resistance results in a lighter load. While in the load of a constant voltage source, a larger resistance results in a lighter load. In the electrical industry, light load means that an electrical control component can drive a load of the same power under the condition of rated power, but the torque it outputs is smaller. Example: The light load application of a frequency converter is 7.5KW, which means that when the frequency converter is at rated power, it can drive a motor of the same power, and this motor can only start under light load, with a smaller output torque of the motor.

[0041] And the output current and output voltage of the first three-phase resonant output circuit 22 will have different characteristics under the working states of no load, light load, full load, and overload.

[0042] Furthermore, the first control circuit 23 processes the currently obtained output voltage or output current using one or more of any reasonable feedback regulation methods such as a PI controller (proportional integral controller), a voltage loop, a current loop, etc. to obtain a feedback regulation signal, and then generates a three-phase drive control signal or a two-phase drive control signal using this feedback regulation signal according to the currently determined three-phase wave generation mode or two-phase wave generation mode.

[0043] In some embodiments, the three-phase drive control signal and the two-phase drive control signal can specifically be one or more of any reasonable control signals such as PWM (Pulse Width Modulation) signals or PFM (Pulse Frequency Modulation) signals, and the present application does not limit this.

[0044] S13: Adjust the switching state of the three-phase switch circuit using the three-phase drive control signal or the two-phase drive control signal to adjust the output voltage or output current.

[0045] Specifically, the first control circuit 23 correspondingly sends the currently generated three-phase drive control signal or two-phase drive control signal to three phases or any two phases of the first three-phase switch circuit 21 to adjust the switching state of three phases or any two phases of the first three-phase switch circuit 21, thereby adjusting the output voltage or output current to meet the current load demand.

[0046] In the above solution, by responding to the changes in the magnitudes of the output current and output voltage, flexible switching between the two-phase wave generation mode and the three-phase wave generation mode is achieved. When in light load or no-load conditions, the first three-phase switch circuit 21 is controlled to operate in the two-phase full-bridge mode. At this time, it is equivalent to only two arms of the first three-phase switch circuit 21 operating alternately to achieve two-phase wave generation, so as to ensure the stability of the output voltage and its DC gain curve state, which helps to improve the efficiency and stability of the first three-phase resonant conversion circuit 20 when the load is light. Moreover, in the case of heavy load or high output power requirements, it can also operate in the three-phase interleaved parallel mode to make full use of the advantages of three-phase interleaved parallel connection.

[0047] Please refer to Figure 3 and Figure 4 , where Figure 3 is a schematic flowchart of the second implementation manner of the control method of the three-phase resonant conversion circuit of the present application, Figure 4 and is a schematic structural diagram of a specific embodiment of the three-phase resonant conversion circuit of the present application. The control method of the three-phase resonant conversion circuit in this implementation manner is Figure 1 a schematic flowchart of a refined implementation manner of the control method of the three-phase resonant conversion circuit in

[0048] S41: Detect whether it is the first power-on.

[0049] For ease of understanding, as Figure 4 shown, in this implementation manner, taking the second three-phase resonant conversion circuit 30 as a three-phase interleaved parallel LLC topology circuit as an example, the second three-phase switch circuit 31 further specifically includes a first-phase switch sub-circuit 311, a second-phase switch sub-circuit 312, and a third-phase switch sub-circuit 313 that are phase-coupled. The second three-phase switch circuit 31 is used to be coupled to the power supply circuit 101 to receive the input voltage Vin provided by the power supply circuit 101. The first-phase switch sub-circuit 311 includes a first switch tube Q1 and a second switch tube Q2. The second-phase switch sub-circuit 312 includes a third switch tube Q3 and a fourth switch tube Q4. The third-phase switch sub-circuit 313 includes a fifth switch tube Q5 and a sixth switch tube Q6.

[0050] Herein, the "three-phase" can be understood as the first-phase switch sub-circuit 311, the second-phase switch sub-circuit 312, and the third-phase switch sub-circuit 313, while the "two-phase" corresponds to any two of the first-phase switch sub-circuit 311, the second-phase switch sub-circuit 312, and the third-phase switch sub-circuit 313.

[0051] Specifically, the second three-phase resonant output circuit 32 may further include a three-phase resonant circuit 321, a three-phase isolation transformer circuit 322, a three-phase rectifier circuit 323, and a regulated output circuit 324. The three-phase resonant circuit 321 includes a first resonant inductor Lr1, a first resonant capacitor Cr1, a second resonant inductor Lr2, a second resonant capacitor Cr2, a third resonant inductor Lr3, and a third resonant capacitor Cr3. The three-phase isolation transformer circuit 322 includes a first primary winding Lm1, a second primary winding Lm2, a third primary winding Lm3, a first secondary winding Ln1, a second secondary winding Ln2, and a third secondary winding Ln3. The three-phase rectifier circuit 323 includes a first diode D1, a second diode D2, a third diode D3, a fourth diode D4, a fifth diode D5, and a sixth diode D6. The regulated output circuit 324 includes a regulated resistor Ro.

[0052] Wherein, the second end of the first switching transistor Q1 is coupled to the second end of the third switching transistor Q3 and the second end of the fifth switching transistor Q5, and is used to be coupled to the first end of the power supply circuit 101. The third end of the first switching transistor Q1 is coupled to the second end of the second switching transistor Q2 and the first end of the first resonant inductor Lr1. The third end of the third switching transistor Q3 is coupled to the second end of the fourth switching transistor Q4 and the first end of the second resonant inductor Lr2. The third end of the fifth switching transistor Q5 is coupled to the second end of the sixth switching transistor Q6 and the first end of the third resonant inductor Lr3. The third end of the second switching transistor Q2 is coupled to the third end of the fourth switching transistor Q4 and the third end of the sixth switching transistor Q6, and is used to be coupled to the second end of the power supply circuit 101. The first end of each of the first switching transistor Q1, the second switching transistor Q2, the third switching transistor Q3, the fourth switching transistor Q4, the fifth switching transistor Q5, and the sixth switching transistor Q6 is coupled to a control circuit (not shown in the figure), and each has a freewheeling diode and a parasitic capacitor inside.

[0053] The second end of the first resonant inductor Lr1 is coupled to the first end of the first resonant capacitor Cr1. The second end of the second resonant inductor Lr2 is coupled to the first end of the second resonant capacitor Cr2. The second end of the third resonant inductor Lr3 is coupled to the first end of the third resonant capacitor Cr3. The second end of the first resonant capacitor Cr1 is coupled to the first end of the first primary winding Lm1. The second end of the second resonant capacitor Cr2 is coupled to the first end of the second primary winding Lm2. The second end of the third resonant capacitor Cr3 is coupled to the first end of the third primary winding Lm3. The second end of the first primary winding Lm1 is coupled to the second end of the second primary winding Lm2 and the second end of the third primary winding Lm3. The first primary winding Lm1 is coupled to the first secondary winding Ln1. The second primary winding Lm2 is coupled to the second secondary winding Ln2. The third primary winding Lm3 is coupled to the third secondary winding Ln3. The first end of the first secondary winding Ln1 is coupled to the first end of the first diode D1 and the second end of the second diode D2. The first end of the second secondary winding Ln2 is coupled to the first end of the third diode D3 and the second end of the fourth diode D4. The first end of the third secondary winding Ln3 is coupled to the first end of the fifth diode D5 and the second end of the sixth diode D6. The second end of the first secondary winding Ln1 is coupled to the second end of the second secondary winding Ln2 and the second end of the second secondary winding Ln2. The second end of the first diode D1 is coupled to the second end of the third diode D3, the second end of the fifth diode D5, and the first end of the voltage stabilizing resistor Ro, and is used to be coupled to the first end of the signal function circuit. The second end of the first end of the second diode D2 is coupled to the first end of the fourth diode D4, the first end of the sixth diode D6, and the second end of the voltage stabilizing resistor Ro, and is used to be coupled to the second end of the signal function circuit.

[0054] In other embodiments, the second three-phase resonant output circuit 32 may specifically further include a greater number of inductors, and / or resistors, and / or capacitors. Each secondary winding in the three-phase isolation transformer circuit 322 may specifically further have at least two sub-windings. Each diode in the three-phase rectifier circuit 323 may specifically be replaced with a switching transistor. The voltage stabilizing output circuit 324 may specifically further include a voltage stabilizing capacitor and may also be integrated into the signal function circuit at the backend. That is, the second three-phase resonant conversion circuit 30 may specifically be any other reasonable topological form of a three-phase LLC resonant topology circuit, which is specifically determined by the actual application scenario, and the present application does not make any limitation thereto.

[0055] In some embodiments, the first switching transistor Q1, the second switching transistor Q2, the third switching transistor Q3, the fourth switching transistor Q4, the fifth switching transistor Q5, and the sixth switching transistor Q6 may specifically be one of MOS (Metal Oxide Semiconductor Field-Effect Transistor) transistors, triodes, thin-film transistors, or field-effect transistors, or any other reasonable switching transistor. The present application does not make any limitations in this regard.

[0056] It should be noted that to distinguish the two ends of each of the above switching transistors other than the control end, one of the poles is referred to as the second end, and the other pole is referred to as the third end. When each switching transistor is a triode, the control end, that is, the first end, may specifically be the base, the second end is the collector, and the third end is the emitter; or, the first end may specifically also be the base, the second end is the emitter, and the third end is the collector.

[0057] When each of the above switching transistors is a MOS transistor, a thin-film transistor, or a field-effect transistor, the first end may specifically be the gate, the second end is the drain, and the third end is the source; or, the first end may specifically also be the gate, the second end is the source, and the third end is the drain.

[0058] Among them, when each switching transistor is a MOS transistor, a thin-film transistor, or a field-effect transistor, it may specifically be a composite transistor or a single transistor. The present application does not make any limitations in this regard.

[0059] In some embodiments, the control circuit may specifically include one of a control chip, an MCU (Micro Controller Unit) circuit, a CPU (Central Processing Unit), a single-chip microcomputer, a field-programmable gate array, a programmable logic device, discrete gates, or transistor logic devices, discrete hardware, or any other reasonable circuit unit with signal processing functions. The present application does not make any limitations in this regard.

[0060] Specifically, when determining the current control mode, the control circuit first detects whether it is the first power-on, that is, performs a power-on detection to determine whether it enters the control mode for the first time.

[0061] Among them, if it is the first power-on currently, then execute S42; if it is not the first power-on, then execute S44.

[0062] S42: Obtain the output current and / or output voltage of the three-phase resonant output circuit.

[0063] Among them, S42 is the same as Figure 1 S11 in, and for specific details, please refer to S11 and its related text descriptions, which will not be elaborated here.

[0064] S43: Generate a two-phase drive control signal using the output current or output voltage.

[0065] The control circuit enters the two-phase wave generation mode to obtain the output voltage Vo or output current Io of the second three-phase resonant output circuit 32 by real-time sampling, so as to generate a two-phase drive control signal using the feedback regulation of the output voltage Vo or output current Io.

[0066] It should be noted that the three-phase drive control signal in this article can be specifically understood as the first drive signal, the second drive signal, and the third drive signal respectively sent to the first-phase switch sub-circuit 311, the second-phase switch sub-circuit 312, and the third-phase switch sub-circuit 313. That is, the three-phase drive control signal specifically includes the first drive signal, the second drive signal, and the third drive signal; and for every two of the first drive signal, the second drive signal, and the third drive signal, the phase difference is 120 degrees under normal circumstances; in addition, for each of the two drive signals corresponding to the two switching tubes in each of the first-phase switch sub-circuit 311, the second-phase switch sub-circuit 312, and the third-phase switch sub-circuit 313, the phase difference is 180 degrees.

[0067] In addition, the two-phase drive control signal can be specifically understood as the first control signal and the second control signal respectively sent to any two of the first-phase switch sub-circuit 311, the second-phase switch sub-circuit 312, and the third-phase switch sub-circuit 313. That is, the two-phase drive control signal specifically includes the first control signal and the second control signal; under normal circumstances, the phase difference between the first control signal and the second control signal is 180 degrees, and the phase difference between the first control signal and the second control signal can also be adjusted according to the control requirements; however, for each of the two control signals corresponding to the two switching tubes in each of any two of the first-phase switch sub-circuit 311, the second-phase switch sub-circuit 312, and the third-phase switch sub-circuit 313 that receive the first control signal and the second control signal respectively, the phase difference is 180 degrees.

[0068] S44: Detect whether the output current is greater than the two-phase maximum output current.

[0069] Specifically, the control circuit detects whether the output current of the second three-phase resonant output circuit 32 obtained by current sampling is greater than the two-phase maximum output current.

[0070] Among them, if the output current is greater than the two-phase maximum output current, then execute S45; if the output current is not greater than the two-phase maximum output current, then execute S46.

[0071] S45: Generate a three-phase drive control signal using the output current or output voltage.

[0072] The control circuit enters the three-phase wave generation mode to generate a three-phase drive control signal by using the feedback regulation of the output voltage Vo or the output current Io.

[0073] S46: Detect whether the output voltage is greater than the two-phase maximum output voltage.

[0074] The control circuit detects whether the currently obtained output voltage Vo is greater than the two-phase maximum output voltage.

[0075] Among them, if the output voltage Vo is greater than the two-phase maximum output voltage, then execute S45; if the output voltage Vo is not greater than the two-phase maximum output voltage, then execute S47.

[0076] S47: Detect whether the frequency of the pre-transmission drive signal generated by using the output current or the output voltage is greater than the three-phase maximum wave generation frequency.

[0077] Based on the feedback regulation signal obtained from the currently obtained output voltage Vo or output current Io of the control circuit, that is, the output signal given by any reasonable regulation controller such as the corresponding PI controller, speed loop or current loop, etc., and further detect the frequency of the pre-transmission drive signal of this feedback regulation signal, that is, whether the control signal frequency currently required by the second three-phase switch circuit 31 is greater than the three-phase maximum wave generation frequency.

[0078] It should be noted that the three-phase maximum wave generation frequency can be specifically obtained by monitoring and calculating the stress of each switching tube in the second three-phase resonant output circuit 32 and the state of the output DC gain curve, and reasonably setting and adjusting the calculation results.

[0079] Among them, if the frequency of the pre-transmission drive signal is greater than the three-phase maximum wave generation frequency, then execute S43; if the frequency of the pre-transmission drive signal is not greater than the three-phase maximum wave generation frequency, then execute S48.

[0080] S48: Detect whether the frequency of the pre-transmission drive signal is less than the two-phase minimum wave generation frequency.

[0081] The control circuit further detects whether the frequency of the pre-transmission drive signal is less than the two-phase minimum wave generation frequency.

[0082] It should be noted that the two-phase minimum wave generation frequency can be specifically obtained by calculating the acceptable current ripple on the input side of the second three-phase resonant output circuit 32 and reasonably setting and adjusting the calculation results.

[0083] S49: Generate a two-phase drive control signal by using the output current or the output voltage.

[0084] The control circuit enters the two-phase wave generation mode to obtain the output voltage Vo or output current Io of the second three-phase resonant output circuit 32 through real-time sampling, so as to generate a two-phase drive control signal by means of feedback regulation of the output voltage Vo or output current Io.

[0085] S410: Detect whether a three-phase drive control signal is generated currently.

[0086] The control circuit detects and determines whether it is currently in the three-phase wave generation mode or the two-phase wave generation mode, that is, detects whether a three-phase drive control signal is generated currently, or can also detect whether a two-phase drive control signal is generated currently.

[0087] Among them, if a three-phase drive control signal is generated currently, then execute S411; if the signal generated currently is not a three-phase drive control signal, that is, a two-phase drive control signal, then execute S417.

[0088] S411: Detect whether the frequency of the pre-transmission drive signal is greater than the three-phase maximum wave generation frequency.

[0089] The control circuit detects and determines whether the frequency of the pre-transmission drive signal obtained currently is greater than the three-phase maximum wave generation frequency.

[0090] Among them, if the frequency of the pre-transmission drive signal is greater than the three-phase maximum wave generation frequency, then execute S412; if the frequency of the pre-transmission drive signal is not greater than the three-phase maximum wave generation frequency, then execute S416.

[0091] S412: Adjust the pulse width of the three-phase drive control signal by using the output current or output voltage.

[0092] The control circuit uses the output voltage Vo or output current Io of the second three-phase resonant output circuit 32 obtained currently to adjust the pulse width of the three-phase drive control signal in real time by means of pulse width modulation.

[0093] S413: Detect whether the pulse width of the adjusted three-phase drive control signal is less than the minimum pulse width.

[0094] The control circuit further detects whether the pulse width of the adjusted three-phase drive control signal is less than the minimum pulse width.

[0095] It should be noted that the minimum pulse width can be specifically obtained by monitoring and calculating the stress of each switching tube in the second three-phase resonant output circuit 32 and the state of the output DC gain curve, and reasonably setting and adjusting the calculation results.

[0096] Among them, if the pulse width of the adjusted three-phase drive control signal is less than the minimum pulse width, then execute S414; if the pulse width of the adjusted three-phase drive control signal is not less than the minimum pulse width, then execute S415.

[0097] S414: Perform on - off regulation on the three - phase drive control signal.

[0098] The control circuit performs on - off regulation on the three - phase drive control signal in a three - phase Burst mode, that is, continuously sends the three - phase drive control signal to the second three - phase switch circuit 31 for a first duration, then stops sending the three - phase drive control signal to the second three - phase switch circuit 31 for a second duration, and adjusts the duration ratio of wave generation and wave stop.

[0099] It should be noted that the Burst mode is a mode that works under light - load conditions, mainly used to reduce switching losses and conduction losses and improve system efficiency. In the Burst mode, the conduction time of the switching device is very short, and the frequency of the switching pulse is also greatly reduced, which makes the ripple of the system output voltage Vo larger, but at the same time improves the output efficiency of the system.

[0100] S415: Send the first drive signal, the second drive signal, and the third drive signal to the first - phase switch sub - circuit, the second - phase switch sub - circuit, and the third - phase switch sub - circuit respectively, to respectively adjust the switching states of the first - phase switch sub - circuit, the second - phase switch sub - circuit, and the third - phase switch sub - circuit, so as to adjust the output voltage Vo or the output current Io.

[0101] The control circuit sends the first drive signal, the second drive signal, and the third drive signal to the first - phase switch sub - circuit 311, the second - phase switch sub - circuit 312, and the third - phase switch sub - circuit 313 respectively, so that the first - phase switch sub - circuit 311, the second - phase switch sub - circuit 312, and the third - phase switch sub - circuit 313 change their switching states under the action of the first drive signal, the second drive signal, and the third drive signal respectively, so as to adjust the output voltage of the second three - phase resonant output circuit 32 to meet the power consumption requirements of the backend signal function circuit.

[0102] S416: Use the output current or output voltage to adjust the signal frequency of the three - phase drive control signal.

[0103] The control circuit uses the currently obtained output voltage Vo or output current Io of the second three - phase resonant output circuit 32 to perform real - time adjustment on the signal frequency of the three - phase drive control signal in a frequency - adjustment manner.

[0104] S417: Detect whether the frequency of the pre - sent drive signal is greater than the two - phase maximum wave - generation frequency.

[0105] The control circuit detects whether the frequency of the currently obtained pre - sent drive signal is less than the two - phase maximum wave - generation frequency.

[0106] Among them, if the frequency of the pre-transmission drive signal is not greater than the two-phase maximum wave generation frequency, S418 is executed; if the frequency of the pre-transmission drive signal is less than the two-phase maximum wave generation frequency, S422 is executed.

[0107] S418: Adjust the phase difference between the first control signal and the second control signal.

[0108] The control circuit performs phase shift adjustment on the first control signal and / or the second control signal to adjust the phase difference between the first control signal and the second control signal.

[0109] Among them, the control circuit can specifically gradually reduce the phase difference between the first control signal and the second control signal, and gradually reduce the phase difference between the first control signal and the second control signal using any reasonable functional relationship such as a linear function or an arithmetic sequence function with time as the independent variable. It is specifically determined by the actual application scenario, and the present application does not limit this.

[0110] S419: Detect whether the phase difference between the adjusted first control signal and the second control signal is less than the minimum phase difference.

[0111] The control circuit further detects whether the phase difference between the adjusted first control signal and the second control signal is less than the minimum phase difference.

[0112] Among them, if the phase difference between the adjusted first control signal and the second control signal is less than the minimum phase difference, S420 is executed; if the phase difference between the adjusted first control signal and the second control signal is not less than the minimum phase difference, S421 is executed.

[0113] S420: Perform on-off adjustment on the first control signal and the second control signal.

[0114] The control circuit performs on-off adjustment on the first control signal and the second control signal in a two-phase Burst mode, that is, continuously sends the first control signal and the second control signal to any two of the first-phase switch sub-circuit 311, the second-phase switch sub-circuit 312, and the third-phase switch sub-circuit 313 for a first duration, then stops wave generation for a second duration, and adjusts the duration ratio of wave generation and stop wave generation.

[0115] S421: Send the first control signal and the second control signal to any two of the first-phase switch sub-circuit, the second-phase switch sub-circuit, and the third-phase switch sub-circuit respectively to adjust the switch states of any two of the first-phase switch sub-circuit, the second-phase switch sub-circuit, and the third-phase switch sub-circuit respectively, so as to adjust the output voltage Vo or the output current Io.

[0116] The control circuit sends the first control signal and the second control signal to any two of the first-phase switch sub-circuit 311, the second-phase switch sub-circuit 312, and the third-phase switch sub-circuit 313 respectively, so that any two of the first-phase switch sub-circuit 311, the second-phase switch sub-circuit 312, and the third-phase switch sub-circuit 313 change their switch states respectively under the action of the first control signal and the second control signal, thereby adjusting the output voltage Vo or the output current Io of the second three-phase resonant output circuit 32 to meet the power consumption requirements of the backend signal function circuit.

[0117] S422: Adjust the signal frequency of the two-phase drive control signal by using the output current or the output voltage.

[0118] The control circuit uses the currently obtained output voltage Vo or output current Io of the second three-phase resonant output circuit 32 of the three-phase resonant conversion circuit to adjust the signal frequency of the two-phase drive control signal in real time by means of frequency adjustment.

[0119] Further, in an embodiment, S410 described above can specifically be replaced with: Detect whether a two-phase drive control signal is currently generated.

[0120] It can be understood that the control circuit detects and determines whether it is currently in a three-phase wave generation mode or a two-phase wave generation mode, that is, detects whether a three-phase drive control signal is currently generated, or can also detect whether a two-phase drive control signal is currently generated.

[0121] Among them, if a two-phase drive control signal is currently generated, then S417 is executed; if what is currently generated is not a two-phase drive control signal, that is, a three-phase drive control signal, then S411 is executed.

[0122] This application also provides an electronic device. Please refer to Figure 5 , Figure 5 which is a schematic structural diagram of an embodiment of the electronic device of this application. In this embodiment, the electronic device 50 includes a housing 51 and a third three-phase resonant conversion circuit 52 connected to the housing 51.

[0123] It should be noted that the third three-phase resonant conversion circuit 52 described in this embodiment is the first three-phase resonant conversion circuit 20 or the second three-phase resonant conversion circuit 30 described in any of the above embodiments. For details, please refer to Figures 1 - 4 and the relevant text content, which will not be elaborated here.

[0124] The beneficial effects of the present application are as follows: Different from the prior art, the control method of the three-phase resonant conversion circuit provided by the present application obtains the output current and / or output voltage of the three-phase resonant output circuit, and generates a three-phase drive control signal or a two-phase drive control signal based on the first comparison result between the output current and the two-phase maximum output current and / or the second comparison result between the output voltage and the two-phase maximum output voltage, and uses the three-phase drive control signal or the two-phase drive control signal to adjust the switching state of the three-phase switch circuit to adjust the output voltage or output current, so as to be able to flexibly switch between the two-phase wave generation mode and the three-phase wave generation mode in response to the changes in the magnitudes of the output current and output voltage. When the load is light or no-load, the three-phase switch circuit is controlled to operate in the two-phase full-bridge mode. At this time, it is equivalent to only two bridge arms of the three-phase switch circuit operating alternately to achieve two-phase wave generation, so as to ensure the stability of the output voltage and its DC gain curve state, which helps to improve the efficiency and stability of the three-phase resonant conversion circuit when the load is light; and in the case of heavy load or high output power required, it can also operate in the three-phase interleaved parallel mode to make full use of the advantages of three-phase interleaved parallel.

[0125] The above are only the embodiments of the present application, and do not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made by using the content of the specification and drawings of the present application, or directly or indirectly applied to other related technical fields, shall be similarly included in the patent protection scope of the present application.

Claims

1. A control method for a three-phase resonant conversion circuit, the three-phase resonant conversion circuit comprising a three-phase switch circuit and a three-phase resonant output circuit, the three-phase switch circuit being coupled to the three-phase resonant output circuit and being used for coupling to a power supply circuit, characterized in that, The control method of the three-phase resonant conversion circuit includes: Obtaining the output current and / or output voltage of the three-phase resonant output circuit; Generating a three-phase drive control signal or a two-phase drive control signal based on a first comparison result between the output current and two-phase maximum output currents and / or a second comparison result between the output voltage and two-phase maximum output voltages; wherein, the generating of the three-phase drive control signal or the two-phase drive control signal based on the first comparison result between the output current and two-phase maximum output currents and / or the second comparison result between the output voltage and two-phase maximum output voltages includes: when it is determined that the output current is greater than the two-phase maximum output currents, generating the three-phase drive control signal in a three-phase wave generation mode; when it is determined that the output current is not greater than the two-phase maximum output currents and the output voltage is not greater than the two-phase maximum output voltages, generating the two-phase drive control signal in a two-phase wave generation mode; Adjusting the switching states of the three-phase switch circuit by using the three-phase drive control signal or the two-phase drive control signal to adjust the output voltage or the output current.

2. The control method of the three-phase resonant conversion circuit according to claim 1, wherein The step of generating the three-phase drive control signal or the two-phase drive control signal based on the first comparison result between the output current and two-phase maximum output currents and / or the second comparison result between the output voltage and two-phase maximum output voltages includes: Detecting whether the output current is greater than the two-phase maximum output currents; If the output current is greater than the two-phase maximum output currents, generating the three-phase drive control signal by using the output current or the output voltage; Wherein, the three-phase switch circuit includes a first-phase switch sub-circuit, a second-phase switch sub-circuit, and a third-phase switch sub-circuit that are phase-coupled, and the first-phase switch sub-circuit, the second-phase switch sub-circuit, and the third-phase switch sub-circuit are coupled to the three-phase resonant output circuit and are used to be coupled to the power supply circuit; the three-phase drive control signal includes a first drive signal, a second drive signal, and a third drive signal; The step of adjusting the switching states of the three-phase switch circuit by using the three-phase drive control signal or the two-phase drive control signal to adjust the output voltage or the output current includes: Sending the first drive signal, the second drive signal, and the third drive signal to the first-phase switch sub-circuit, the second-phase switch sub-circuit, and the third-phase switch sub-circuit respectively to adjust the switching states of the first-phase switch sub-circuit, the second-phase switch sub-circuit, and the third-phase switch sub-circuit respectively, so as to adjust the output voltage or the output current.

3. The control method of the three-phase resonant conversion circuit according to claim 2, characterized in that The control method of the three-phase resonant conversion circuit further includes: If the output current is not greater than the two-phase maximum output currents, detecting whether the output voltage is greater than the two-phase maximum output voltages; If the output voltage is not greater than the two-phase maximum output voltages, detecting whether the frequency of a pre-transmission drive signal generated by using the output current or the output voltage is greater than the three-phase maximum wave generation frequency; If the frequency of the pre - transmitted driving signal is greater than the three - phase maximum wave - sending frequency, generate a two - phase driving control signal using the current output current or output voltage; wherein, the two - phase driving control signal includes a first control signal and a second control signal; The step of adjusting the switching state of the three - phase switching circuit using the three - phase driving control signal or the two - phase driving control signal to adjust the output voltage or output current includes: Send the first control signal and the second control signal to any two of the first - phase switching sub - circuit, the second - phase switching sub - circuit, and the third - phase switching sub - circuit respectively to adjust the switching states of any two of the first - phase switching sub - circuit, the second - phase switching sub - circuit, and the third - phase switching sub - circuit respectively, so as to adjust the output voltage or output current.

4. The control method of the three-phase resonant conversion circuit according to claim 3, characterized in that, The control method of the three - phase resonant conversion circuit further includes: If the frequency of the pre - transmitted driving signal is not greater than the three - phase maximum wave - sending frequency, detect whether the frequency of the pre - transmitted driving signal is less than the two - phase minimum wave - sending frequency; If the frequency of the pre - transmitted driving signal is less than the two - phase minimum wave - sending frequency, generate the three - phase driving control signal using the current output current or output voltage.

5. The control method of the three-phase resonant conversion circuit according to claim 4, characterized in that, The control method of the three - phase resonant conversion circuit further includes: Detect whether the three - phase driving control signal or the two - phase driving control signal is generated currently; If the three - phase driving control signal is generated currently, detect whether the frequency of the pre - transmitted driving signal is greater than the three - phase maximum wave - sending frequency; If the frequency of the pre - transmitted driving signal is greater than the three - phase maximum wave - sending frequency, adjust the pulse width of the three - phase driving control signal using the output current or output voltage.

6. The control method of the three-phase resonant conversion circuit according to claim 5, wherein After the step of adjusting the duty cycle of the three - phase driving control signal using the output voltage, it further includes: Detect whether the pulse width of the adjusted three - phase driving control signal is less than the minimum pulse width; If the pulse width of the adjusted three - phase driving control signal is less than the minimum pulse width, perform on - off adjustment on the three - phase driving control signal.

7. The control method of the three-phase resonant conversion circuit according to claim 5, characterized in that The control method of the three - phase resonant conversion circuit further includes: If the frequency of the pre - transmitted driving signal is not greater than the three - phase maximum wave - sending frequency, adjust the signal frequency of the three - phase driving control signal using the output current or output voltage.

8. The control method of the three-phase resonant conversion circuit according to claim 4, characterized in that The control method of the three - phase resonant conversion circuit further includes: Detect whether the three - phase driving control signal or the two - phase driving control signal is generated currently; If the two - phase driving control signal is generated currently, detect whether the frequency of the pre - transmitted driving signal is greater than the two - phase maximum wave - sending frequency; If the frequency of the pre - transmitted driving signal is not greater than the two - phase maximum wave - sending frequency, adjust the phase difference between the first control signal and the second control signal.

9. The control method of the three-phase resonant conversion circuit according to claim 8, characterized in that, After the step of adjusting the phase difference between the first control signal and the second control signal, it further includes: Detect whether the phase difference between the adjusted first control signal and the second control signal is less than the minimum phase difference; If the phase difference between the adjusted first control signal and the second control signal is less than the minimum phase difference, perform on / off adjustment on the first control signal and the second control signal.

10. The control method of the three-phase resonant conversion circuit according to claim 8, characterized in that, The control method of the three-phase resonant conversion circuit further includes: If the frequency of the pre-transmission drive signal is less than the two-phase maximum wave generation frequency, adjust the signal frequency of the two-phase drive control signal by using the output current or the output voltage.

11. The control method of the three-phase resonant conversion circuit according to any one of claims 2-10, characterized in that, Before the step of detecting whether the output current is greater than the two-phase maximum output current, it further includes: Detect whether it is the first power-on; If it is the first power-on currently, generate the two-phase drive control signal by using the output current or the output voltage.

12. A three-phase resonant conversion circuit, characterized in that, The three-phase resonant conversion circuit includes a three-phase switch circuit, a three-phase resonant output circuit, and a control circuit. The three-phase switch circuit is coupled to the three-phase resonant output circuit and is used to be coupled to a power supply circuit. The control circuit is coupled to the three-phase switch circuit and the three-phase resonant output circuit; Wherein, the control circuit is used to control the three-phase switch circuit by adopting the control method of the three-phase resonant conversion circuit according to any one of claims 1-11.

13. An electronic device, characterized in that, The electronic device includes a housing and a three-phase resonant conversion circuit connected to the housing; Wherein, the three-phase resonant conversion circuit is the three-phase resonant conversion circuit according to claim 12.

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