Three-leg resonant topology charge type control circuit, control system and control method

Abstract

This invention provides a charge-type control circuit, control system, and control method for a three-arm resonant topology. The charge-type control circuit controls a three-arm resonant topology circuit to perform six-step commutation. A circuit output feedback module collects the output electrical signal of the three-arm resonant topology circuit and processes the signal to obtain a feedback result. An integral comparison module collects the primary resonant signal, calculates the integral result, compares the integral result with the feedback result, and outputs a pulse trigger signal based on the comparison result. A drive generation module outputs a frequency adjustment signal to the three-arm resonant topology circuit based on the pulse trigger signal. The frequency adjustment signal controls the three-arm resonant topology circuit to perform six-step commutation. By triggering the state flip of the switching transistor when the integral calculation result reaches a preset threshold, inconsistencies in the parameters of the resonant components between the bridge arms that lead to uneven current flow are avoided, thus improving the device's lifespan and reliability.

Description

Technical Field

[0001] This invention relates to the field of power electronic power conversion technology, and in particular to a three-bridge resonant topology charge-type control circuit, control system and control method. Background Technology

[0002] With the increasing demands for power density and efficiency in applications such as data centers and electric vehicle charging stations, three-arm resonant topology circuits are widely used because they can significantly reduce input and output voltage and current ripple and improve power levels.

[0003] However, in practical engineering applications, the traditional Pulse Frequency Modulation (PFM) control of the three-arm resonant topology is a second-order system. The compensation network design is complex, and the response speed to transient load changes is slow. Furthermore, due to manufacturing tolerances in the resonant inductors, capacitors, and transformers, even if the drive signal frequencies of each arm are completely identical during commutation, significant differences in current between the arms will still occur. Although the three-arm resonant topology is structurally equivalent to a parallel combination of three half-bridge LLC topologies, the inconsistency in the resonant inductors, capacitors, and transformers among the arms makes it easy for the charge-collecting control circuit in the three-arm resonant topology structure to cause inconsistent switching frequencies among the three half-bridges. Consequently, the drive signals cannot maintain their phase difference, ultimately resulting in severe current unevenness among the arms, reduced device lifespan and reliability, and even damage to the internal electronic components of the three-arm resonant topology.

[0004] Therefore, existing technologies still need to be improved and developed. Summary of the Invention

[0005] In view of the shortcomings of the prior art, the purpose of this invention is to provide a three-arm resonant topology charge-type control circuit, control system and control method to solve the problem that the existing three-arm resonant topology charge-type control is prone to causing inconsistent switching frequencies of the three half-bridges, resulting in severe uneven current in each arm, which leads to reduced service life and reliability of the devices or even damage.

[0006] The technical solution of the present invention is as follows: This invention provides a charge-type control circuit for a three-arm resonant topology, used to control a three-arm resonant topology circuit to perform six-step commutation, comprising: The circuit output feedback module is connected to the output terminal of the three-arm resonant topology circuit, and is used to acquire the output electrical signal of the three-arm resonant topology circuit and perform signal processing on the output electrical signal to obtain the feedback result. The integration comparison module is connected to the primary side of the three-arm resonant topology circuit and the circuit output feedback module, respectively. It is used to collect the primary resonant signal of the primary side of the three-arm resonant topology circuit and integrate it, compare the integral calculation result generated by integration with the feedback result, and output a pulse trigger signal according to the comparison result. The drive generation module is connected to the input terminals of the integral comparison module and the three-arm resonant topology circuit. It is used to receive the pulse trigger signal and output a frequency adjustment signal to the three-arm resonant topology circuit according to the pulse trigger signal. The frequency adjustment signal is used to control the three-arm resonant topology circuit to perform six-step commutation.

[0007] In a further embodiment of the present invention, the integral comparison module includes an absolute value unit, an adder unit, an integrator unit, a result comparison unit, and a monostable trigger; wherein, The primary resonant signal is the three-arm bridge current; the input terminal of the absolute value unit is connected to the bridge arm of the three-arm bridge resonant topology circuit, used to collect the three-arm bridge current, calculate the absolute value of the three-arm bridge current respectively, and output the three absolute value currents to the adder unit. The adder unit is connected to the integrator unit and is used to perform addition operations on the three absolute currents and output the current detection result to the integrator unit. The integrator unit is connected to the result comparison unit and is used to integrate the current detection result, obtain and output the integration calculation result to the result comparison unit. The result comparison unit is connected to the circuit output feedback module and the monostable multivibrator respectively, and is used to compare the feedback result and the integral calculation result, and output a comparison characterization signal to the monostable multivibrator according to the comparison result; The monostable trigger is connected to the drive generation module and is used to output a pulse trigger signal to the drive generation module according to the comparison characterization signal.

[0008] In a further embodiment of the present invention, the integral comparison module includes an integrator unit, a result comparison unit, and a monostable trigger; wherein, The primary resonant signal is the total input current; the input terminal of the integrator unit is connected to the current input terminal of the three-arm resonant topology circuit, and is used to collect the total input current to obtain the current detection result, integrate the current detection result, and obtain and output the integration calculation result to the result comparison unit. The result comparison unit is connected to the circuit output feedback module and the monostable multivibrator respectively, and is used to compare the feedback result and the integral calculation result, and output a comparison characterization signal to the monostable multivibrator according to the comparison result; The monostable trigger is connected to the drive generation module and is used to output a pulse trigger signal to the drive generation module according to the comparison characterization signal.

[0009] In a further embodiment of the present invention, the result comparison unit is connected to the reset control terminal of the integrator unit, and is used to output the comparison characterization signal to the monostable multivibrator and output the comparison characterization signal to the reset control terminal of the integrator unit, wherein the integrator unit is reset according to the comparison characterization signal.

[0010] In a further embodiment of the present invention, the circuit output feedback module includes a difference calculation unit and a feedback loop unit. The difference calculation unit is connected to the feedback loop unit and is used to calculate the difference between the output electrical signal and a predetermined given value, and output the difference to the feedback loop unit. The feedback loop unit uses a feedback control algorithm to perform feedback calculation based on the difference to obtain a feedback result.

[0011] In a further embodiment of the present invention, the integral comparison module further includes a slope compensation module. The first end of the slope compensation module is connected to the current detection result, the second end of the slope compensation module is connected to the slope compensation constant, and the output end of the slope compensation module is connected to the integrator unit. The integrator unit is used to add the current detection result and the slope compensation constant, and output the slope compensation result to the integrator unit. The integrator unit is used to integrate the slope compensation result, obtain and output the integral calculation result to the result comparison unit.

[0012] In a further embodiment of the present invention, the drive generation module includes a signal distribution unit and a dead-time control unit; wherein, The signal distribution unit is connected to the integral comparison module and is used to output six power switch drive signals according to the pulse trigger signal; The dead-time control unit is connected to the signal distribution unit and the three-arm resonant topology circuit respectively, and is used to receive the six power switch drive signals, add dead time to the six power switch drive signals, and output the frequency adjustment signal to the three-arm resonant topology circuit.

[0013] In a further embodiment of the present invention, the driver generation module includes: a sequence allocation unit, a driver generation unit, and a dead-time control unit; wherein, The sequential allocation unit is connected to the integral comparison module and is used to allocate the pulse trigger signal to six output terminals and output six parallel pulse signals; The drive generation unit is connected to the sequence allocation unit and is used to receive the six parallel pulse signals and generate six power switch drive signals according to the six parallel pulse signals. The six parallel pulse signals control the state flipping of the six power switch drive signals. The dead-time control unit is connected to the drive generation unit and the three-arm resonant topology circuit respectively, and is used to receive the six power switch drive signals, add dead time to the six power switch drive signals, and output the frequency adjustment signal to the three-arm resonant topology circuit.

[0014] Based on the same inventive concept, the present invention also provides a control system, which includes the three-arm resonant topology charge-type control circuit and the three-arm resonant topology circuit described above. The three-arm resonant topology charge-type control circuit is connected to the three-arm resonant topology circuit and is used to acquire the output electrical signal and the primary resonant signal of the three-arm resonant topology circuit, and output a frequency adjustment signal to the three-arm resonant topology circuit according to the output electrical signal and the primary resonant signal; the three-arm resonant topology circuit realizes commutation according to the frequency adjustment signal.

[0015] Based on the same inventive concept, the present invention also provides a control method, wherein the above-described three-arm resonant topology charge-type control circuit is used to implement the control method, the steps of which include: The initial operating state of the six power switching devices is determined based on the initial vector of the three-arm resonant topology circuit. When the three-arm resonant topology circuit is working, charge-type control is enabled; the circuit output feedback module collects the output electrical signal at the output terminal of the three-arm resonant topology circuit and calculates the feedback result based on the output electrical signal; The integration comparison module acquires the primary resonance signal on the primary side of the three-arm resonant topology circuit, calculates the integration result based on the primary resonance signal, compares the integration result with the feedback result, and outputs a pulse trigger signal based on the comparison result. The control drive generation module outputs a frequency adjustment signal to the three-arm resonant topology circuit according to the pulse trigger signal, so that the three-arm resonant topology circuit can realize commutation according to the frequency adjustment signal; The repetitive charge-type control process continues until the three-arm resonant topology circuit completes a six-step commutation process within one control cycle according to the frequency adjustment signal.

[0016] This invention provides a charge-type control circuit, control system, and control method for a three-arm resonant topology. The charge-type control circuit for the three-arm resonant topology is used to control the three-arm resonant topology circuit to perform six-step commutation. It includes: a circuit output feedback module connected to the output terminal of the three-arm resonant topology circuit, used to acquire the output electrical signal of the three-arm resonant topology circuit and perform signal processing on the output electrical signal to obtain a feedback result; an integral comparison module connected to the primary side of the three-arm resonant topology circuit and the circuit output feedback module respectively, used to acquire the primary resonant signal of the primary side of the three-arm resonant topology circuit and perform integration, compare the integral calculation result with the feedback result, and output a pulse trigger signal according to the comparison result; and a drive generation module connected to the integral comparison module and the input terminal of the three-arm resonant topology circuit, used to receive the pulse trigger signal and output a frequency adjustment signal to the three-arm resonant topology circuit according to the pulse trigger signal. The frequency adjustment signal is used to control the three-arm resonant topology circuit to perform six-step commutation. This invention compares the integral calculation result of the acquired primary resonant signal with the reference signal from the voltage loop compensator. When the integral calculation result reaches a preset threshold, it triggers the state flip of the switching transistor, thereby achieving precise control of the energy transmitted in each switching cycle. This avoids uneven current caused by inconsistent parameters of the resonant elements between bridge arms, and improves the lifespan and reliability of the device. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the three-bridge arm resonant topology charge-type control circuit in this invention.

[0019] Figure 2 This is the circuit diagram of a three-arm resonant topology circuit.

[0020] Figure 3 The circuit diagram of the three-bridge-arm resonant topology charge-type control circuit in a preferred embodiment of the present invention.

[0021] Figure 4 This is a circuit diagram of a three-bridge-arm resonant topology charge-type control circuit in another preferred embodiment of the present invention.

[0022] Figure 5 This is a circuit diagram of a three-bridge-arm resonant topology charge-type control circuit in a preferred embodiment of the present invention, which includes a slope compensation module.

[0023] Figure 6 This is a circuit diagram of a preferred embodiment of the three-bridge-arm resonant topology charge-type control circuit with a slope compensation module, which is another part of the present invention.

[0024] Figure 7 This is a circuit diagram of the drive generation module of the three-bridge-arm resonant topology charge-type control circuit in a preferred embodiment of the present invention.

[0025] Figure 8 This is a circuit diagram of the drive generation module of the three-bridge-arm resonant topology charge-type control circuit in another preferred embodiment of the present invention.

[0026] Figure 9 This is a waveform diagram of the six parallel pulse signals in this invention.

[0027] Figure 10 This is a waveform diagram of the frequency adjustment signal in this invention.

[0028] Figure 11 This is a flowchart of the control method in this invention.

[0029] The labels in the attached diagram are as follows: 1. Three-arm resonant topology circuit; 100. Circuit output feedback module; 200. Integrator comparison module; 210. Absolute value unit; 220. Adder unit; 230. Integrator unit; 240. Result comparison unit; 250. Monostable multivibrator; 260. Slope compensation module; 261. Second adder; 300. Drive generation module; 310. Signal distribution unit; 320. Dead zone control unit; 330. Sequence distribution unit; 340. Drive generation unit. Detailed Implementation

[0030] This invention provides a three-arm resonant topology charge-type control circuit, control system, and control method. To make the objectives, technical solutions, and effects of this invention clearer and more explicit, the invention is further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0031] In the implementation methods and claims, unless otherwise specified in the text, the terms "a," "an," "the," and "the" may also include plural forms. If the embodiments of the present invention involve descriptions of "first," "second," etc., such descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features.

[0032] It should be further understood that the term "comprising" as used in this specification means the presence of the stated features, integers, steps, operations, elements, and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. It should be understood that when we say an element is "connected" or "coupled" to another element, it can be directly connected or coupled to the other element, or there may be intermediate elements. Furthermore, "connected" or "coupled" as used herein can include wireless connections or wireless coupling. The term "and / or" as used herein includes all or any unit and all combinations of one or more associated listed items.

[0033] It will be understood by those skilled in the art that, unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. It should also be understood that terms such as those defined in general dictionaries should be understood to have the same meaning as in the context of the prior art, and should not be interpreted in an idealized or overly formal sense unless specifically defined as herein.

[0034] Furthermore, the technical solutions of the various embodiments can be combined with each other, but only if they are feasible for those skilled in the art. If the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0035] The inventors discovered that with the increasing demands for power density and efficiency in applications such as data centers and electric vehicle charging stations, existing half-bridge and full-bridge LLC converters, limited by the size of magnetic components and output ripple, struggle to meet the requirements of high-power applications. The three-arm resonant topology is widely used due to its ability to significantly reduce input and output voltage and current ripple, thereby improving power ratings. However, during operation, the traditional PFM voltage control mode is a second-order system due to limitations in traditional frequency control, resulting in complex compensation network design and slow response to load transients. Furthermore, manufacturing tolerances (typically 5%–10%) in resonant inductors, capacitors, and transformers lead to significant current differences between arms, even with identical drive signal frequencies. To address these issues, charge-mode control was developed to achieve frequency modulation control in high-power applications. The charge-mode control method and related circuits can eliminate the double-pole characteristics in the LLC topology power stage model, reducing the system order to approximately first-order, thus simplifying compensation network design and improving the system's transient response to sudden load changes. However, charge-type control is not widely used in three-arm resonant topology converters. Taking an LLC topology circuit as an example, although a three-arm LLC topology circuit is essentially composed of three half-bridge LLC topologies connected in parallel, the inconsistencies in the resonant inductors, capacitors, and transformers mean that directly applying the charge-type control method of half-bridge LLC converters to three-arm LLC converters will result in inconsistent switching frequencies among the three half-bridges. The drive signals will also be unable to maintain a 120° phase difference, ultimately leading to severe current imbalances in the three half-bridges. This inevitably causes overheating of electronic components, reduces their lifespan and reliability, and may even damage the internal electronic components of the three-arm resonant topology.

[0036] To address the technical problems existing in the prior art, the present invention provides a three-arm resonant topology charge-type control circuit for controlling the three-arm resonant topology circuit to perform six-step commutation.

[0037] First, the present invention describes the type of three-arm resonant topology circuit it controls. For example, Figure 2The diagram shows a three-arm LLC topology where both the primary and secondary sides of the transformer are Y-connected. This structure includes six power switching devices on the primary side: a first switch S1, a second switch S2, a third switch S3, a fourth switch S4, a fifth switch S5, and a sixth switch S6. Each of these six switches forms one arm: S1 is the upper switch on the first arm, S2 is the lower switch on the first arm, S3 is the upper switch on the second arm, S4 is the lower switch on the second arm, S5 is the upper switch on the third arm, and S6 is the lower switch above the third arm. Thus, during operation of the three-arm resonant topology, six-step commutation is achieved by controlling the on / off state of these six power switching devices. Correspondingly, on the primary side, it also includes three sets of resonant elements corresponding to the three bridge arms. Specifically, each set has a first resonant inductor L. r1 Second resonant inductor L r2 and the third resonant inductor L r3 The first resonant inductor L r1 One end of the second resonant inductor is connected to the first bridge arm, that is, to the common terminal of the first switch S1 and the second switch S2; r2 One end is connected to the second bridge arm, namely the third switch S3 and the fourth switch S4; the third resonant inductor L r3 One end is connected to the third bridge arm, that is, the common terminal of the fifth switch S5 and the sixth switch S6. It also includes a first resonant capacitor C connected to the other end of each resonant inductor respectively. r1 Second resonant capacitor C r2 and the third resonant capacitor C r3 and respectively with the first resonant capacitor C r1 Second resonant capacitor C r2 and the third resonant capacitor C r3The other end is connected to the first transformer T1, the second transformer T2, and the third transformer T3, where Lm1 represents the magnetizing inductance of the primary winding of the first transformer T1, Lm2 represents the magnetizing inductance of the primary winding of the second transformer T2, and Lm3 represents the magnetizing inductance of the primary winding of the third transformer T3. The secondary winding of the transformer is connected to a rectifier circuit, which includes six rectifier diodes: 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, as well as an output filter capacitor Co. In some preferred embodiments, it can also be replaced by six power MOSFETs to form a synchronous rectifier circuit. The load resistor Ro is located at the output terminal of the three-arm resonant topology circuit, and the load resistor Ro is used to represent any form of existing load. For the three-arm LLC topology, in terms of driving mode, the upper and lower transistors of each arm are 50% square wave waveforms, and the driving signals of the three arms have a 120° phase difference. In addition to the above structure, the three-arm LLC circuit topology can also change the circuit connection method of the primary and secondary sides of the transformer to a delta connection method respectively; furthermore, the structure of the secondary rectifier circuit can also be changed to three independent full-bridge rectifier circuits, etc. Since the technical solution of this patent application is universal, it can be used for different three-arm LLC topologies. That is, the three-arm resonant topology circuit described in this invention can adopt any of the various three-arm resonant topologies, such as LLC, LCC, LCL, and CLLC. The three-arm resonant topology charge-type control circuit described in this invention can be used in any device using an existing three-arm resonant topology circuit; the circuit topology will not be elaborated in detail here. The following uses a three-arm LLC topology structure in which both the primary and secondary sides of the transformer are Y-connected as an example to specifically illustrate the control scheme adopted in this application.

[0038] like Figure 1As shown, the charge-type control circuit of the three-arm resonant topology includes: a circuit output feedback module 100, connected to the output terminal of the three-arm resonant topology circuit 1, for acquiring the output electrical signal of the three-arm resonant topology circuit 1 and processing the output electrical signal to obtain a feedback result; an integration comparison module 200, connected to the primary side of the three-arm resonant topology circuit 1 and the circuit output feedback module 100 respectively, for acquiring the primary resonant signal of the primary side of the three-arm resonant topology circuit 1 and integrating it, comparing the integral calculation result generated by integration with the feedback result, and outputting a pulse trigger signal according to the comparison result, wherein the pulse trigger signal undergoes a level jump when the comparison result meets the trigger condition; and a drive generation module 300, connected to the input terminal of the integration comparison module 200 and the three-arm resonant topology circuit 1, for receiving the pulse trigger signal and outputting a frequency adjustment signal to the three-arm resonant topology circuit 1 according to the pulse trigger signal, wherein the frequency adjustment signal is used to control the three-arm resonant topology circuit 1 to complete six-step commutation.

[0039] Specifically, the charge-type control circuit of the three-arm resonant topology is connected to the three-arm resonant topology circuit 1. When the three-arm resonant topology circuit 1 is working, it outputs an output electrical signal for driving the load. For example, the output electrical signal can be a working voltage or a working current. The circuit output feedback module 100 detects the output electrical signal and processes it to obtain a feedback result. The feedback result is used as an integration threshold. Correspondingly, the integration comparison module 200 acquires the primary resonant signal on the primary side of the three-arm resonant topology circuit 1. The primary resonant signal can be a signal from any position on the primary side of the three-arm resonant topology circuit 1. For example, it can be any signal that can be used to characterize and calculate the charge change state under its working state, such as the voltage or current signal at the input terminal. It can also be a voltage or current signal at the position of the three arms, or a voltage or current signal at the position of the resonant inductor or resonant capacitor. There are no restrictions here. The integration comparison module 200 integrates the primary resonant signal to obtain an integration calculation result, and compares the integration calculation result with the feedback result used as the integration threshold. When the comparison result meets the trigger condition, it outputs a rising edge to the drive generation module 300. Then, the integration comparison module 200 automatically resets and outputs a low level again, which is macroscopically manifested as a pulse trigger signal whose level changes continuously with the number of cycles. Similarly, the integration comparison module 200 can also default to outputting a high level and use the low level output when the comparison result meets the trigger condition for drive control. The drive generation module 300 generates a frequency adjustment signal based on the pulse trigger signal to control the operating frequency and duty cycle of the high-frequency switch in the three-arm resonant topology circuit 1, limiting the charge change of the resonant capacitor in each switching cycle. Correspondingly, the frequency adjustment signal is also a pulse signal. The rising / falling edge of this pulse signal serves as the drive trigger signal for each power switching device. That is, when a rising or falling edge of a pulse signal is received, the corresponding power switching device undergoes a state flip. This allows for automatic commutation by determining the commutation timing based on the accumulated charge during the operation of the three-arm resonant topology circuit 1. This control scheme does not rely on frequency or time references; instead, it directly locks the charge change through the charge integration threshold. It is unaffected by differences in the consistency of operating parameters of the resonant inductor, resonant capacitor, and transformer. This innovative control scheme introduces charge-based control into the three-arm LLC topology. Even with inconsistencies in the parameters of the resonant components between the arms, it can still maintain the consistency of the switching frequencies of the three half-bridges and preserve the phase relationship of the three half-bridge drive signals during the six-step commutation process, ensuring stable operation of the three-arm LLC topology under charge-based control.

[0040] Please refer to the following: Figure 1 , Figure 2 and Figure 3The three-arm resonant topology charge-type control circuit includes three sets of resonant networks and corresponding power switching devices. The control circuit sums the absolute values ​​of the three resonant currents and then performs an integral operation. The integral calculation result is compared with the calculation result of the output voltage control loop. When the comparison result meets the trigger condition, the integral comparison module 200 generates a trigger pulse signal. The trigger pulse signal is sent to the drive generation module 300 and generates a frequency adjustment signal through the dead-time control module. The frequency adjustment signal is the final drive signal. Figure 3 In the three-arm LLC topology shown, the three arms of the transformer primary are denoted as the first arm A, the second arm B, and the third arm C, respectively. The two switching states on each phase arm are complementary.

[0041] Define a switch function Such as S a =1, meaning the upper switch of the first bridge arm A is turned on and the lower switch is turned off; S a =0 represents the opposite state, where the upper switch of the first bridge arm A is off and the lower switch is on. Assume... Figure 3 In the middle, the first switching transistor If the fourth switch S4 and the sixth switch S6 are turned on, and the second switch S2, the third switch S3, and the fifth switch S5 are turned off, then the switching function for the corresponding state can be expressed as: S a =1,S b =0, S c =0. The three switch function values ​​are characterized in... Figure 3 On the spatial vector diagram, the switching state of power switching devices can be represented by a switching state vector, where each bit of the switching state vector corresponds to one phase arm. For example, in this case, if the upper arm of the first arm A is on, and the lower arms of the second arm B and the third arm C are on, then the switching state vector is 100.

[0042] Similarly, when the switch state vector state is 110, it means that the first switch S1, the third switch S3, and the sixth switch S6 are turned on, and the second switch S2, the fourth switch S4, and the fifth switch S5 are turned off. When the switch state vector state is 010, it means that the second switch S2, the third switch S3, and the sixth switch S6 are turned on, and the first switch S1, the fourth switch S4, and the fifth switch S5 are turned off. When the switch state vector state is 011, it means that the second switch S2, the third switch S3, and the fifth switch S5 are turned on, and the first switch S1, the fourth switch S4, and the sixth switch S6 are turned off. When the switch state vector state is 001, it means that the second switch S2, the fourth switch S4, and the fifth switch S5 are turned on, and the first switch S1, the third switch S3, and the sixth switch S6 are turned off. When the switch state vector state is 101, it means that the first switch S1, the fourth switch S4, and the fifth switch S5 are turned on, and the second switch S2, the third switch S3, and the sixth switch S6 are turned off. At any given moment, the state of the power switching devices in the three-arm LLC topology can be represented by one of the six switching state vectors mentioned above. These six switching state vectors are arranged in a fixed order; for visual clarity, they are placed with a 60° offset from each other, forming... Figure 3 The spatial vector diagram of the position of the drive generation module 300 shows that the ends of the switch state vectors correspond to the six vertices of a hexagon. In some preferred embodiments, the initial state of the three-arm resonant topology circuit 1 can be any one of the six switch state vectors. After the pulse trigger circuit generates continuous pulse signals and sends them to the drive generation module 300, the power switching devices of the three-arm resonant topology circuit 1 rotate clockwise or counterclockwise according to the arrangement of the six switch state vectors. Taking the initial state of switch state vector 100 as an example, after the drive generation module 300 receives the continuous pulse trigger signals in sequence, it flips the power switch state in sequence according to the switch state vectors 100, 110, 010, 011, 001, 101, 100 (counterclockwise) or 100, 101, 001, 011, 010, 110, 100 (clockwise). Each time a rising edge of a trigger pulse is received, the power switch state moves forward one step, realizing commutation, and the above working process is continuously repeated. As can be seen, if the spatial vector diagram contains six switching state vectors, then the primary side includes six different switching states during the commutation process, thus achieving six-step commutation. Furthermore, it directly locks the charge change through the charge integration threshold, ensuring the consistency of the three half-bridge switching frequencies during the six-step commutation process.

[0043] In a preferred embodiment of the present invention, the integration and comparison module 200 includes an absolute value unit 210, an adder unit 220, an integrator unit 230, a result comparison unit 240, and a monostable multivibrator 250; wherein, the primary resonant signal is the three bridge arm currents; the input terminal of the absolute value unit 210 is connected to the bridge arm of the three-bridge arm resonant topology circuit 1, and is used to collect the three bridge arm currents and perform absolute value calculations on the three bridge arm currents respectively, and output the three absolute value currents to the adder unit 220; the adder unit 220 is connected to the integrator unit 230, and is used to perform addition operations on the three absolute value currents and output current detection. The result is sent to the integrator unit 230; the integrator unit 230 is connected to the result comparison unit 240, and is used to integrate the current detection result, obtain and output the integral calculation result to the result comparison unit 240; the result comparison unit 240 is connected to the circuit output feedback module 100 and the monostable multivibrator 250 respectively, and is used to compare the feedback result and the integral calculation result, and output a comparison characterization signal to the monostable multivibrator 250 according to the comparison characterization signal; the monostable multivibrator 250 is connected to the drive generation module 300, and is used to output a pulse trigger signal to the drive generation module 300 according to the comparison characterization signal.

[0044] The absolute value unit 210 includes a first absolute value arithmetic unit, a second absolute value arithmetic unit, and a third absolute value arithmetic unit. The input terminal of the first absolute value arithmetic unit is connected to the common terminal CT1 of the first resonant capacitor and the first transformer on the first bridge arm, and the output terminal of the first absolute value arithmetic unit is connected to the adder unit 220. Correspondingly, the input terminal of the second absolute value arithmetic unit is connected to the common terminal CT2 of the second resonant capacitor and the second transformer on the second bridge arm, and the output terminal of the second absolute value arithmetic unit is connected to the adder unit 220. The input terminal of the third absolute value arithmetic unit is connected to the common terminal CT3 of the third resonant capacitor and the third transformer on the third bridge arm, and the output terminal of the third absolute value arithmetic unit is connected to the adder unit 220. In this invention, the three resonant cavity current waveforms are AC signals with a 120° phase offset, and the waveforms are close to sine waves. Therefore, the absolute values ​​of the currents on the three bridge arms, i.e., the three corresponding resonant cavities, are calculated by the first, second, and third absolute value arithmetic units to obtain the three absolute value currents, thereby measuring the three-channel charge throughput. Further, the three absolute currents are added together by an adder to obtain the total throughput of the current on the three resonant cavities. The integrator unit 230 performs integration to obtain an integral calculation result, which is proportional to the signal amplitude and is used to characterize the total charge over a period of time, so as to facilitate condition judgment and control by the subsequent control circuit. The result comparison unit 240 is used to compare the integral calculation result with the feedback result. For example, the comparison result satisfying the trigger condition can refer to the moment when the integral calculation result is greater than the feedback result. When the integral calculation result is greater than the feedback result, which is the integral threshold, the result comparison unit 240 outputs a high-level comparison characterization signal. In this preferred embodiment, the comparison characterization signal can be high-level active or rising edge active. The monostable multivibrator 250 is used to receive the comparison characterization signal and convert the rising edge active comparison characterization signal into a pulse trigger signal. The pulse trigger signal is a continuous pulse sequence with a fixed width and standard amplitude. The monostable multivibrator 250 is used to shape variable-length or non-ideal signals into a fixed time window, thus playing a pulse shaping role. In this invention, the charge of the three resonant cavities in the three-arm resonant topology circuit 1 is no longer integrated from the resonant current of a single cavity. Instead, the absolute values ​​of the currents in the three resonant cavities are added together and then integrated to obtain an integral calculation result that reflects the overall resonant energy change of the system. This integral calculation result is compared with the calculation result of the output voltage control loop, and a pulse trigger signal is output based on the comparison characterization signal obtained from the comparison result, thereby achieving stable output of the pulse trigger signal under charge-type control.

[0045] In another preferred embodiment of the invention, such as Figure 4As shown, the integration comparison module 200 includes an integrator unit 230, a result comparison unit 240, and a monostable multivibrator 250; wherein, the primary resonant signal is the total input current; the input terminal CT of the integrator unit 230 is connected to the current input terminal of the three-arm resonant topology circuit 1, and is used to collect the total input current to obtain the current detection result, integrate the current detection result, and obtain and output the integration calculation result to the result comparison unit 240; the result comparison unit 240 is connected to the circuit output feedback module 100 and the monostable multivibrator 250 respectively, and is used to compare the feedback result and the integration calculation result, and output a comparison characterization signal to the monostable multivibrator 250 according to the comparison characterization signal; the monostable multivibrator 250 is connected to the drive generation module 300, and is used to output a pulse trigger signal to the drive generation module 300 according to the comparison characterization signal.

[0046] In this preferred embodiment, the integration of the three resonant currents can be directly obtained by collecting and integrating the total input current of the six power switching devices on the primary side of the transformer. The structure and operating state of other units in this embodiment can be consistent with those in the embodiment of three-bridge arm current acquisition, and will not be described again here. The input terminal of the integrator unit 230 can be connected to the common terminal of the second switch S2, the fourth switch S4, and the sixth switch S6 of the lower switching devices, that is, it is set in the three-bridge arm resonant topology circuit 1. Its effect is the same as that of the embodiment of collecting the absolute value current of the three bridge arms for calculation, while simplifying the implementation of the current acquisition integration circuit, eliminating the current transformer connected in series in each half-bridge resonant cavity circuit, and further reducing costs.

[0047] The circuit output feedback module 100 includes a difference calculation unit (not shown in the figure) and a feedback loop unit (not shown in the figure). The difference calculation unit is connected to the feedback loop unit and is used to calculate the difference between the output electrical signal and a predetermined given value, and output the difference to the feedback loop unit. The feedback loop unit uses a feedback control algorithm to perform feedback calculation based on the difference to obtain a feedback result. After signal processing of the output electrical signal, a feedback control algorithm is also used to perform feedback calculation, and then outputs a feedback result used as an integral threshold. Specifically, after the output voltage or output current is acquired by the acquisition circuit, the acquired value is subtracted from the given value in the control system in the difference calculation unit. The difference is calculated by the compensation loop in the feedback loop unit to obtain the final calculation result, that is, the feedback result of the output voltage / current loop, and is used for feedback adjustment. The compensation loop in the feedback loop unit can be implemented by various feedback control algorithms. For example, in the circuit output feedback module 100, it adopts either a proportional-integral-derivative (PID) circuit or a proportional-integral (PI) circuit. Besides using common proportional-integral-derivative (PI-DI) and proportional-integral (PI) operations, other algorithms, such as PI-DI, feedforward control, neural network compensation, and linear quadratic regulator (LQR) algorithms, can also be used. The internal structure of the controller or feedback unit used in these algorithms is existing technology and will not be elaborated upon here. The core implementation of the charge-type control method lies in comparing the signal characterizing the system's resonant energy change with the calculation result of the feedback loop compensation stage to form a signal for controlling the switching on and off of the power switching devices. In a single-resonant-cavity circuit, the signal characterizing the system's resonant energy change can be obtained by acquiring and integrating the voltage of the resonant capacitor or the resonant current. It should be noted that in this application, the absolute values ​​of the three resonant cavity currents can be summed first, and then integrated to obtain the signal characterizing the system's resonant energy change; alternatively, the total input current of the three bridge arms can be acquired and integrated, both achieving the same technical effect.

[0048] In a further embodiment of some preferred embodiments, the result comparison unit 240 is connected to the reset control terminal of the integrator unit 230, and is used to output the comparison characterization signal to the monostable multivibrator 250 and the comparison characterization signal to the reset control terminal of the integrator unit 230, wherein the integrator unit 230 is reset according to the comparison characterization signal. That is, in the same cycle of outputting the integral operation value, the integrator unit 230 synchronously performs a reset and clearing operation at the rising edge of the pulse signal, and restarts integration from 0. Preferably, the comparison characterization signal output by the result comparison unit 240 can be reused as the reset signal of the integrator unit 230 while serving as a toggle signal, that is, the integrator unit 230 resets when the reset control terminal detects the rising edge of the comparison characterization signal and restarts the integration operation. At this time, since the integral calculation result is cleared to zero, the comparison characterization signal output by the result comparison signal returns to a low level, thereby enabling the integrator unit 230 to be automatically reset according to the output result of the result comparison unit 240, realizing the pulse output of the comparison characterization signal, and then enabling the output of a stable pulse trigger signal to the drive generation module 300.

[0049] Ramp compensation is a crucial element in charge-type control, effectively improving its stability. When the output power of a resonant topology is low, such as under no-load or light-load conditions, the amplitude of the signal characterizing the system's resonant energy change is low, making it susceptible to noise interference and causing the topology to enter an unstable operating state. This phenomenon exists in half-bridge, full-bridge, or three-arm resonant topologies and is an inherent problem of charge-type control. To address this issue, ramp compensation typically employs two common implementation methods: one is to subtract an upwardly accumulated ramp signal from the output of the feedback loop compensation stage, where the ramp signal's reset time coincides with the integrator's reset time in charge-type control. The other method is to superimpose an upwardly accumulated ramp signal onto the integrator's output. In practice, ramp compensation is achieved either through the digital controller's internal DAC (Digital-to-Analog Converter) or by adding an additional ramp generation circuit within the circuitry.

[0050] Please see Figure 5 and Figure 6In some preferred embodiments, the integration comparison module 200 further includes a slope compensation module 260. The first end of the slope compensation module 260 is connected to the current detection result, the second end of the slope compensation module 260 is connected to the slope compensation constant, and the output end of the slope compensation module 260 is connected to the integrator unit 230 for adding the current detection result and the slope compensation constant, and outputting the slope compensation result to the integrator unit 230. The integrator unit 230 is used to integrate the slope compensation result, obtain and output the integration calculation result to the result comparison unit 240.

[0051] The slope compensation module 260 includes a second adder 261 and a slope compensation constant generation unit (not shown in the figure). The first input terminal of the second adder 261 is connected to the current detection result, and the second input terminal of the second adder 261 is connected to the slope compensation constant generation unit, which is used to generate a slope compensation constant. In specific implementations, depending on the adopted embodiment, it can be connected to the adder unit 220 used to add the three absolute currents, or it can be directly connected to the current input terminal of the three-bridge arm resonant topology circuit 1, or to other charge acquisition circuits, and added to the slope compensation constant connected to the second input terminal of the second adder 261. This invention, based on the sum of the absolute currents of the three resonant cavities before the integrator or the acquisition of the total input current, superimposes a slope compensation constant, thus achieving the same effect as the aforementioned two slope compensation methods, effectively saving hardware circuit overhead while reducing the requirements for the digital controller. In this patent application, the slope compensation constant characterizes the slope of the slope compensation signal, which can be a fixed constant or different values ​​depending on different system operating conditions. In engineering applications, the slope compensation constant is selected based on the magnitude of the resonant energy characterization signal. This signal is an integral calculation result, specifically the result of integrating the absolute values ​​of the three resonant cavity currents, or the result of integrating the total input current of the three bridge arms. In engineering applications, the slope compensation constant is typically taken as 0.1 to 0.6 times the amplitude of the integral calculation result. Within this range, the topology circuit can operate stably under no-load or light-load conditions, while maintaining the dynamic characteristics of the overall charge-type control system tending towards a first-order system, simplifying the compensation network design and improving the system's transient response speed to sudden load changes.

[0052] In some preferred embodiments, such as Figure 7 and Figure 9As shown, the drive generation module 300 includes: a sequence allocation unit 330, a drive generation unit 340, and a dead-time control unit 320; wherein, the sequence allocation unit 330 is connected to the integral comparison module 200, and is used to allocate the pulse trigger signal to six output terminals and output six parallel pulse signals; the drive generation unit 340 is connected to the sequence allocation unit 330, and is used to receive the six parallel pulse signals and generate six power switch drive signals according to the six parallel pulse signals, the six parallel pulse signals controlling the state flipping of the six power switch drive signals; the dead-time control unit 320 is connected to the drive generation unit 340 and the three-arm resonant topology circuit 1 respectively, and is used to receive the six power switch drive signals, add a dead time to the six power switch drive signals, and output the frequency adjustment signal to the three-arm resonant topology circuit 1.

[0053] In this preferred embodiment, the pulse trigger signal is input to the sequence allocation unit 330 for sequential allocation processing. The sequence allocation unit 330 can be implemented using a frequency divider or a counter, etc., so that the continuously generated trigger pulses are sequentially allocated to six output terminals in a predetermined order, forming six parallel pulse signals. For example, its initial state is that the second switch S2, the third switch S3, and the sixth switch S6 are turned on, and the first switch S1, the fourth switch S4, and the fifth switch S5 are turned off, corresponding to a switch state vector of 010. When the control circuit starts working, the sequence allocation unit 330 divides the continuous pulse signal from the monostable multivibrator 250 by six to form six parallel pulse signals: the first parallel pulse signal P0, the second parallel pulse signal P1, the third parallel pulse signal P2, the fourth parallel pulse signal P3, the fifth parallel pulse signal P4, and the sixth parallel pulse signal P5. The drive generation unit 340 includes a first RS flip-flop 341, a second RS flip-flop 342, and a third RS flip-flop 342 arranged in parallel, wherein at least one of the first RS flip-flop 341, the second RS flip-flop 342, and the third RS flip-flop 342 is an RS flip-flop, wherein: The first parallel pulse signal P0 and the fourth parallel pulse signal P3 are connected to the setting terminal S and the reset terminal R of the third RS flip-flop 342. At the same time, the output terminal Q and the inverting output terminal of the third RS flip-flop 342 are connected to the setting terminal S and the reset terminal R. These are used to generate the third upper switch drive signal PWMCH and the third lower switch drive signal PWMCL, respectively.

[0054] The second parallel pulse signal P1 and the fifth parallel pulse signal P4 are connected to the setting terminal S and the reset terminal R of the second RS flip-flop 342, and the output terminal Q and the inverting output terminal of the second RS flip-flop 342 are also connected. These are used to generate the second lower switch drive signal PWMBL and the second upper switch drive signal PWMBH, respectively.

[0055] The third parallel pulse signal P2 and the sixth parallel pulse signal P5 are connected to the setting terminal S and the reset terminal R of the first RS flip-flop 341, while the output terminal Q and the inverting output terminal of the first RS flip-flop 341 are also connected. These are used to generate the first upper switch drive signal PWMAH and the first lower switch drive signal PWMAL, respectively.

[0056] The waveform of the parallel pulse signal is as follows: Figure 9 As shown, through the above-described sequential triggering and state-holding control, the switching state vectors corresponding to the power switches on the primary side of the transformer in the three-arm LLC topology will continuously flip their switching states in the order of 010, 011, 001, 101, 100, 110, 010. Since each drive signal remains in the on state after being triggered until the next trigger pulse arrives and triggers the state flip, the flipping time of the drive signal is determined by the rising edge of the output pulse of the monostable multivibrator 250. The dead-time control module adds a dead time to the upper and lower transistor drive flipping signals generated by the drive generation module 300 to prevent damage to the power switching devices caused by shoot-through of the upper and lower transistors in a single bridge arm. This achieves sequential commutation control of the six power switching devices, enabling the three-arm resonant topology circuit 1 to complete a six-step commutation process within one complete control cycle.

[0057] The drive generation module 300 may further include a state holding unit (not shown in the figure). The state holding power supply can be implemented using any existing state holding circuit, or the state can be saved or latched by software. When the six parallel pulse signals are generated, they are further input to the state holding circuit in the drive generation module 300. In some preferred embodiments, the state holding circuit can be implemented using a flip-flop, which can use any existing flip-flop latch circuit, and generates and holds the drive signals of the power switching devices through flip-flop latch logic. The initial output state of the flip-flop in the state holding circuit determines the output state of the six power switching devices on the primary side of the three-arm LLC topology transformer.

[0058] like Figure 8As shown, in another preferred embodiment, the drive generation module 300 includes a signal distribution unit 310 and a dead-time control unit 320; wherein, the signal distribution unit 310 is connected to the integral comparison module 200 and is used to output six power switch drive signals according to the pulse trigger signal; the dead-time control unit 320 is connected to the signal distribution unit 310 and the three-arm resonant topology circuit 1 respectively, and is used to receive the six power switch drive signals, add dead time to the six power switch drive signals, and output the frequency adjustment signal to the three-arm resonant topology circuit 1.

[0059] In this preferred embodiment, the sequential allocation and drive generation functions can also be directly implemented by a state machine composed of several flip-flops. The drive generation module 300 is composed of three D flip-flops, specifically including a first D flip-flop 311, a second D flip-flop 312, and a third D flip-flop 313. The correspondence between the output signal of the drive generation module 300 and the switching states of the six power switching devices in the three-arm LLC is as follows: The output terminal Q of the first D flip-flop 311 is used to output the first parallel pulse signal P0, which, after passing through the dead-time control unit 320, outputs the corresponding first upper switch drive signal PWMAH; its inverted output terminal Used to output the fourth parallel pulse signal P3, which is then output as PWMHL by the dead-time control unit 320.

[0060] The output terminal Q of the second D flip-flop 312 is used to output the second parallel pulse signal P1, which, after passing through the dead-time control unit 320, outputs the corresponding second down-switching drive signal PWMBL; its inverted output terminal The fifth parallel pulse signal P4 is used to output the second upper switch drive signal PWMBH through the dead-time control unit 320.

[0061] The output terminal Q of the third D flip-flop 313 is used to output the third parallel pulse signal P2, which, after passing through the dead-time control unit 320, outputs the corresponding third upper switch drive signal PWMCH; its inverted output terminal The sixth parallel pulse signal P5 is used to output the third lower switch drive signal PWMCL, which is output by the dead-time control unit 320.

[0062] The waveform of the frequency adjustment signal is as follows: Figure 10As shown, in this embodiment, a Johnson counter is constructed using several D flip-flops. Driven by a trigger pulse, the output signals of the flip-flops and their inverted signals cycle according to the aforementioned switching state toggle sequence. After passing through the dead-time control unit 320, six drive signals for the power switching devices are generated: a first upper switch drive signal PWMAH, a second upper switch drive signal PWMBH, a third upper switch drive signal PWMCH, a first lower switch drive signal PWMAL, a second lower switch drive signal PWMBL, and a third lower switch drive signal PWMCL. This achieves sequential conduction control of the three-arm power switching devices. For example, the initial state of the power switching devices is 010, meaning the second switch S2, the third switch S3, and the sixth switch S6 are turned on, and the first switch S1, the fourth switch S4, and the fifth switch S5 are turned off. When the control circuit starts working, after the monostable multivibrator 250 issues the first pulse, the state changes from the first parallel pulse signal P0 to the sixth parallel pulse signal P5 are as follows: P0=0,P1=0,P2=1,P3=1,P4=1,P5=0.

[0063] The corresponding power switch state changes to 011, and after the next pulse arrives, the corresponding power switch state changes to 001; and so on. As the pulse signal of the monostable multivibrator 250 continues to advance, the switching state vector of the transformer primary power device changes to 010, 011, 001, 101, 100, 110, 010, which is the same as the aforementioned counterclockwise switching state vector change method, and will not be repeated here. The dead-time control module is also used to add a dead time to the upper and lower transistor drive flip signals generated by the drive generation module 300 to prevent damage to the power switching devices caused by single-bridge arm upper and lower transistor shoot-through. It can also be equipped with a state holding unit for initial state latching. The specific implementation of the state holding unit is as described in the preferred embodiment above using the sequence allocation unit 330. Similarly, in this implementation scheme, when the initial state of the transformer primary power switching device is different, or the direction of the switching state vector rotation change is different, the corresponding order between the six output pulse signals in the drive generation module 300 and the power switching device must also be adjusted accordingly.

[0064] In addition to the two different implementation methods mentioned above, the drive generation module 300 can also use a digital control chip to achieve the same power device switching state vector rotation change function, which will not be elaborated here.

[0065] Based on the same inventive concept, the present invention also provides a control system, which includes the aforementioned three-arm resonant topology charge-type control circuit and three-arm resonant topology circuit. The three-arm resonant topology charge-type control circuit is connected to the three-arm resonant topology circuit and is used to acquire the output electrical signal and primary resonant signal of the three-arm resonant topology circuit, and output a frequency adjustment signal to the three-arm resonant topology circuit according to the output electrical signal and primary resonant signal; the three-arm resonant topology circuit realizes commutation according to the frequency adjustment signal. The specific implementation is as described in the specific embodiment of the three-arm resonant topology charge-type control circuit, and will not be repeated here.

[0066] Based on the same inventive concept, such as Figure 11 As shown, the present invention also provides a control method, wherein the above-described three-arm resonant topology charge-type control circuit is used to implement the control method, the steps of which include: S100. Determine the initial operating state of the six power switching devices based on the initial vector of the three-arm resonant topology circuit. First, the initial vector refers to the switching state vector in the initial state after power-on. To determine the initial switching state vector of the six power switching devices on the primary side of the transformer in the three-bridge resonant topology, any one of the aforementioned six switching vectors can be selected as the initial vector. Then, based on the selected initial switching state vector, the output connection mode and working mode of the trigger in the drive generation module are determined.

[0067] S200. When the three-arm resonant topology circuit is working, charge-type control is enabled; the circuit output feedback module collects the output electrical signal at the output terminal of the three-arm resonant topology circuit and calculates the feedback result based on the output electrical signal. S300: The integration and comparison module acquires the primary resonant signal on the primary side of the three-arm resonant topology circuit, calculates the integration result based on the primary resonant signal, compares the integration result with the feedback result, and outputs a pulse trigger signal based on the comparison result. Once the initial switch state vector is determined, the three-arm resonant topology begins operation. The position of the integral calculation result starts to rise from 0. When the integral calculation result equals the output result of the feedback loop, the output signal of the integral comparison module triggers a flip, and the monostable multivibrator emits a pulse signal. The first pulse is then distributed to one of the six channels by the sequential allocation module. To ensure that the power switch state vector in the three-arm topology rotates in the aforementioned order, the drive generation module needs to flip the power switch state vector clockwise or counterclockwise after receiving the pulse. Taking the channel that outputs the first parallel pulse signal P0 as an example, if the first parallel pulse signal P0 needs to be connected to the S pin of the second flip-flop (corresponding to counterclockwise rotation) or the S pin of the third flip-flop (corresponding to clockwise rotation), then its flip is 110 (counterclockwise rotation) or 101 (clockwise rotation).

[0068] At this point, the integrator's calculation result is reset.

[0069] S400, the control drive generation module outputs a frequency adjustment signal to the three-arm resonant topology circuit according to the pulse trigger signal, so that the three-arm resonant topology circuit realizes commutation according to the frequency adjustment signal; the specific implementation is as described in the specific embodiment of the three-arm resonant topology charge-type control circuit, and will not be repeated here.

[0070] S500, repetitive charge-type control process, until the three-arm resonant topology circuit completes the six-step commutation process within one control cycle according to the frequency adjustment signal.

[0071] After the integrator is reset, integration restarts from zero. When the integration result reaches a certain value, the signal output by the result comparison unit flips again, and the monostable multivibrator emits a second pulse signal. This pulse signal is then distributed to the next channel, namely the second parallel pulse signal P1, by the distribution module. At this time, after the drive generation module receives the pulse signal of the second parallel pulse signal P1, the second parallel pulse signal P1 is connected to the R pin (corresponding to counterclockwise rotation) or the S pin (corresponding to clockwise rotation) of the first flip-flop. This further flips the state vector of the power switch to 010 (counterclockwise rotation) or 001 (clockwise rotation). The above process is repeated until the three-arm resonant topology circuit completes the six-step commutation process within one control cycle according to the frequency adjustment signal.

[0072] This invention provides a charge-type control circuit, control system, and control method for a three-arm resonant topology. The charge-type control circuit for the three-arm resonant topology is used to control the three-arm resonant topology circuit to perform six-step commutation. It includes: a circuit output feedback module connected to the output terminal of the three-arm resonant topology circuit, used to acquire the output electrical signal of the three-arm resonant topology circuit and perform signal processing on the output electrical signal to obtain a feedback result; an integral comparison module connected to the primary side of the three-arm resonant topology circuit and the circuit output feedback module respectively, used to acquire the primary resonant signal of the primary side of the three-arm resonant topology circuit and perform integration, compare the integral calculation result with the feedback result, and output a pulse trigger signal according to the comparison result; and a drive generation module connected to the integral comparison module and the input terminal of the three-arm resonant topology circuit, used to receive the pulse trigger signal and output a frequency adjustment signal to the three-arm resonant topology circuit according to the pulse trigger signal. The frequency adjustment signal is used to control the three-arm resonant topology circuit to perform six-step commutation. This invention compares the integral calculation result of the acquired primary resonant signal with the reference signal from the voltage loop compensator. When the integral calculation result reaches a preset threshold, it triggers the state flip of the switching transistor, thereby achieving precise control of the energy transmitted in each switching cycle. This avoids uneven current caused by inconsistent parameters of the resonant elements between bridge arms, and improves the lifespan and reliability of the device.

[0073] It should be understood that the application of the present invention is not limited to the examples above. Those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.

Claims

1. A charge-type control circuit for a three-arm resonant topology, used to control a three-arm resonant topology circuit to perform six-step commutation, characterized in that, include: The circuit output feedback module is connected to the output terminal of the three-arm resonant topology circuit, and is used to acquire the output electrical signal of the three-arm resonant topology circuit and perform signal processing on the output electrical signal to obtain the feedback result. An integration comparison module is connected to the primary side of the three-arm resonant topology circuit and the circuit output feedback module, respectively. It is used to collect the primary resonant signal of the three-arm resonant topology circuit and integrate it, compare the integrated calculation result with the feedback result, and output a pulse trigger signal according to the comparison result. The drive generation module is connected to the input terminals of the integral comparison module and the three-arm resonant topology circuit. It is used to receive the pulse trigger signal and output a frequency adjustment signal to the three-arm resonant topology circuit according to the pulse trigger signal. The frequency adjustment signal is used to control the three-arm resonant topology circuit to perform six-step commutation. The integral comparison module includes an absolute value unit, an adder unit, an integrator unit, a result comparison unit, and a monostable multivibrator; wherein, The primary resonant signal is the three-arm bridge current; the input terminal of the absolute value unit is connected to the bridge arm of the three-arm bridge resonant topology circuit, used to collect the three-arm bridge current, calculate the absolute value of the three-arm bridge current respectively, and output the three absolute value currents to the adder unit. The adder unit is connected to the integrator unit and is used to perform addition operations on the three absolute currents and output the current detection result to the integrator unit. The integrator unit is connected to the result comparison unit and is used to integrate the current detection result, obtain and output the integration calculation result to the result comparison unit. The result comparison unit is connected to the circuit output feedback module and the monostable multivibrator respectively, and is used to compare the feedback result and the integral calculation result, and output a comparison characterization signal to the monostable multivibrator according to the comparison result; The monostable multivibrator is connected to the drive generation module and is used to output a pulse trigger signal to the drive generation module according to the comparison characterization signal. The integral comparison module further includes a slope compensation module. The first end of the slope compensation module is connected to the current detection result, the second end of the slope compensation module is connected to the slope compensation constant, and the output end of the slope compensation module is connected to the integrator unit. The integrator unit is used to add the current detection result and the slope compensation constant, and output the slope compensation result to the integrator unit. The integrator unit is used to integrate the slope compensation result, obtain and output the integral calculation result to the result comparison unit. The driver generation module includes: a sequence allocation unit, a driver generation unit, and a dead-time control unit; wherein... The sequential allocation unit is connected to the integral comparison module and is used to allocate the pulse trigger signal to six output terminals and output six parallel pulse signals; The drive generation unit is connected to the sequence allocation unit and is used to receive the six parallel pulse signals and generate six power switch drive signals according to the six parallel pulse signals. The six parallel pulse signals control the state flipping of the six power switch drive signals. The dead-time control unit is connected to the drive generation unit and the three-arm resonant topology circuit respectively, and is used to receive the six power switch drive signals, add dead time to the six power switch drive signals, and output the frequency adjustment signal to the three-arm resonant topology circuit.

2. The three-arm resonant topology charge-type control circuit according to claim 1, characterized in that, The result comparison unit is connected to the reset control terminal of the integrator unit, and is used to output the comparison characterization signal to the monostable multivibrator and output the comparison characterization signal to the reset control terminal of the integrator unit, and the integrator unit is reset according to the comparison characterization signal.

3. The three-arm resonant topology charge-type control circuit according to claim 1, characterized in that, The circuit output feedback module includes a difference calculation unit and a feedback loop unit. The difference calculation unit is connected to the feedback loop unit and is used to calculate the difference between the output electrical signal and a predetermined given value, and output the difference to the feedback loop unit. The feedback loop unit uses a feedback control algorithm to perform feedback calculation based on the difference to obtain a feedback result.

4. A control system, characterized in that, The system includes a three-arm resonant topology charge-type control circuit and a three-arm resonant topology circuit as described in any one of claims 1 to 3. The three-arm resonant topology charge-type control circuit is connected to the three-arm resonant topology circuit and is used to acquire the output electrical signal and primary resonant signal of the three-arm resonant topology circuit, and output a frequency adjustment signal to the three-arm resonant topology circuit according to the output electrical signal and primary resonant signal; the three-arm resonant topology circuit realizes commutation according to the frequency adjustment signal.

5. A control method, characterized in that, When the three-arm resonant topology charge-type control circuit as described in any one of claims 1 to 3 is operating, it is used to implement the control method, the steps of which include: The initial operating state of the six power switching devices is determined based on the initial vector of the three-arm resonant topology circuit. When the three-arm resonant topology circuit is working, charge-type control is enabled; the circuit output feedback module collects the output electrical signal at the output terminal of the three-arm resonant topology circuit and calculates the feedback result based on the output electrical signal; The integration comparison module acquires the primary resonance signal on the primary side of the three-arm resonant topology circuit, calculates the integration result based on the primary resonance signal, compares the integration result with the feedback result, and outputs a pulse trigger signal based on the comparison result. The control drive generation module outputs a frequency adjustment signal to the three-arm resonant topology circuit according to the pulse trigger signal, so that the three-arm resonant topology circuit can realize commutation according to the frequency adjustment signal; The charge-type control process is repeated until the three-arm resonant topology circuit completes the six-step commutation process within one control cycle according to the frequency adjustment signal.

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