Self-adaptive input converter circuit topological structure and control method

Abstract

The invention discloses a self-adaptive input converter circuit topological structure and a control method, and relates to the technical field of power electronics. The circuit comprises a pre-stage reconstruction bridge arm circuit which is used for switching to an AC-DC rectification mode or a DC-DC boost mode according to an AC or DC input type; the rear-stage inverter circuit is cascaded behind the front-stage reconstruction bridge arm circuit and is used for inverting the direct current output by the front-stage reconstruction bridge arm circuit into stable alternating current; and the control module is used for dynamically modulating the switching signal according to the alternating current or direct current input type, and realizing mode switching by controlling the closing and the conduction of the switching tube. According to the invention, seamless switching of AC / DC input can be realized according to the AC / DC rapid switching working mode of the input power supply, the continuity and stability of system power supply are ensured, the problem that an existing single input type converter cannot realize normal operation in an AC / DC hybrid input scene is solved, and the switching loss is also reduced.

Description

Technical Field

[0001] This invention relates to the field of power electronics technology, specifically to an adaptive input converter circuit topology and control method. Background Technology

[0002] With the diversification of energy systems and the large-scale application of power electronic devices, converters need to be able to adapt to both AC and DC inputs while ensuring stable output. This requirement is particularly prominent in scenarios such as integrated photovoltaic-storage-charging power stations, mobile emergency power supplies, and industrial general power supplies, as these systems often need to flexibly connect to multiple power sources, such as grid AC, photovoltaic DC, or battery DC. However, traditional converters can usually only handle a single type of input, which limits the conversion between DC and AC within the same system, and the output type is also relatively fixed and singular. When the power source switches between AC and DC, existing technologies either rely on mechanical relays for physical switching, but this method is prone to arcing and power interruption, or cascade two converters, but this combination also has obvious drawbacks: the rectifier bridge generates additional losses with DC input, and it causes current waveform distortion with AC input.

[0003] These issues directly impact the reliability and efficiency of hybrid power supply systems. For example, in photovoltaic-storage-charging systems, when seamless switching between photovoltaic DC power and grid AC power is required, the response delay of existing converters may lead to equipment restarts or energy waste. To address this, this invention proposes an adaptive input converter circuit topology and control method. Summary of the Invention

[0004] The purpose of this invention is to provide an adaptive input converter circuit topology and control method. By detecting the input type, the operating mode is intelligently switched, achieving automatic identification and seamless switching of the input type. This enables single-circuit compatibility with AC / DC input, automatic identification of input type, and switching of operating mode. It also eliminates redundant rectifier devices and optimizes switching losses through dynamic modulation strategies, thereby improving overall efficiency. This solves the problem that existing single-input-type converters cannot operate normally in AC / DC mixed input scenarios.

[0005] According to a first aspect of the present invention, in order to achieve the above-mentioned objective, the present invention provides the following technical solution: an adaptive input converter circuit topology, comprising: The pre-amplifier reconfiguration arm circuit is used to switch between AC-DC rectification mode and DC-DC boost mode according to the AC or DC input type. When the input is AC, it switches to AC-DC rectification mode, and when the input is DC, it switches to DC-DC boost mode. The subsequent inverter circuit, cascaded after the preceding reconfiguration bridge arm circuit, is used to invert the DC power output from the preceding reconfiguration bridge arm circuit into stable AC power. The control module is used to dynamically modulate the switching signal according to the AC or DC input type, and to switch between AC-DC rectification mode and DC-DC boost mode by controlling the switching transistor to turn it on and off.

[0006] Furthermore, it also includes an input detection module, located at the input port, used to identify the AC or DC input type based on the amplitude change rate and frequency characteristics of the input voltage. The specific judgment principle is as follows: If the rate of change of the input voltage amplitude exceeds the threshold and exhibits periodic frequency characteristics, it is determined to be an AC input; If the rate of change of the input voltage amplitude remains below the threshold, it is determined to be a DC input.

[0007] Regarding the technical solution of this embodiment, the front-end reconfiguration bridge arm circuit includes four IGBT switches Q1, Q2, Q3, Q4, a signal switch, and an inductor L1; in: The emitter of Q1 is connected to the collector of Q2 and the inductor; The collector of Q1 is connected to the collector of Q3; The emitter of Q3 is connected to the collector of Q4; When the input is DC, the emitter of Q2 is connected to the emitter of Q4; when the input is AC, it is connected to the collector of Q4.

[0008] Regarding the technical solution of this embodiment, the input terminal of the back-stage inverter circuit is connected to the output terminal of the reconfigurable bridge arm circuit. The back-stage inverter circuit includes four fully controlled IGBT switches, namely Q5, Q6, Q7, Q8, inductor L2, capacitor C2, and load R2. in: Collectors Q5 and Q6 are connected to the positive terminal of the DC bus; emitters Q7 and Q8 are connected to the negative terminal of the DC bus. The emitter and collector of Q5 are connected together and then connected to the positive terminal of the output. The emitter of Q6 and the collector of Q8 are connected together and then connected to the negative terminal of the output. Inductor L2 and capacitor C2 form an LC filter. Load R1 is connected to the AC output terminal through the LC filter to stabilize the output voltage at the load R1 terminal.

[0009] Regarding the technical solution of this embodiment, the signal switch has two operating positions: When position 1 is closed, the collector of Q2 is directly connected to the positive input terminal, forming an AC-DC full-bridge rectification mode; When position 2 is closed, the collector of Q2 is grounded, and Q1 and Q2 form a BOOST boost circuit using the freewheeling diode.

[0010] In the technical solution of this embodiment, a load R1 is also provided between the front-stage reconfiguration bridge arm circuit and the rear-stage inverter circuit. A capacitor C1 is connected in parallel in front of the load R1 for filtering, and a diode D1 is connected after the load R1 to control the mutual impact between the front-stage reconfiguration bridge arm circuit and the rear-stage inverter circuit.

[0011] In the technical solution of this embodiment, the anode of diode D1 is connected to the intersection of the positive terminals of inductor L1 and capacitor C1, and the cathode of diode D1 is connected to the positive terminal of DC bus to block reverse current surges.

[0012] Regarding the technical solution of this embodiment, the control strategy of the control module in DC-DC boost mode is as follows: When the signal switch is switched to position 2, the collector of Q2 is grounded, turning off the switching transistors Q1, Q3 and Q4. The freewheeling diode of the switching transistor Q1 is turned on, forming a BOOST circuit. The DC voltage is boosted to the target value by dynamically adjusting the PWM duty cycle of Q2 using a PI controller.

[0013] Regarding the technical solution of this embodiment, the control strategy of the control module in AC-DC rectification mode is as follows: When the signal switch is switched to position 1, the switching transistors Q1-Q4 form a PWM rectifier bridge. A dual closed-loop control strategy is adopted: the outer loop PI controller adjusts the output voltage, and the inner loop PI controller tracks the input current waveform to generate PWM drive signals for the switching transistors Q1-Q4.

[0014] According to a second aspect of the present invention, the present invention provides a control method for an adaptive input converter circuit topology, comprising the following steps: S1. The input detection module identifies the AC or DC input type. If the input voltage amplitude change rate exceeds the threshold and has periodic frequency characteristics, it is determined to be AC ​​input; if the input voltage amplitude change rate is consistently below the threshold, it is determined to be DC input. S2. Determine the control mode and execute the corresponding control operation based on whether the input type is DC or AC. The control modes specifically include DC-DC boost mode and AC-DC rectification mode: S21. When in DC-DC boost mode, the control steps are as follows: (S21.1) Calculate the difference between the output voltage reference value V and the actual output voltage value V0; (S21.2) The calculated difference is processed by the proportional-integral controller to obtain the duty cycle signal for dynamically adjusting the switching transistor Q2; (S21.3) The duty cycle signal is directly fed into the PWM module in Simulink for comparison with the PWM signal used to control the Q2 switch; S22. When in AC-DC rectification mode, the control steps are as follows: (S22.1) Calculate the difference between the output voltage reference value V and the actual output voltage value V0; (S22.2) The difference calculated in (S22.1) is processed by the first proportional-integral controller to obtain the reference deviation of the duty cycle; (S22.3) Multiply the input voltage by the gain and then multiply it by the reference deviation, and then compare it with the input current to calculate the difference; (S22.4) The difference calculated in (S22.3) is processed by the second proportional-integral controller and compared with the fundamental wave to generate PWM control signals for control switches Q1-Q4; S3. Input the DC power output from the pre-stage reconfiguration bridge arm circuit into the subsequent inverter circuit to convert the DC power into stable AC power, as follows: (S31) Measure the voltage of the output load and calculate its root mean square (RMS). Compare the calculated RMS value with the ideal value to obtain the difference: (S32) Input the difference obtained in (S31) into the proportional-integral controller and multiply it with the sine wave to generate a modulation signal; (S33) The modulation signal obtained in (S32) is compared with the triangular carrier wave to generate an SPWM wave to achieve stable AC output.

[0015] This invention has at least the following beneficial effects: 1. This invention can quickly switch the operating mode according to whether the input power is AC or DC, achieving seamless switching between AC and DC inputs, ensuring the continuity and stability of the system power supply, and is particularly suitable for application scenarios that require frequent switching of power supply types.

[0016] 2. In the DC input mode, the signal switch is switched to position 2 to form a BOOST loop. The PWM duty cycle is dynamically adjusted by the PI controller to achieve efficient DC voltage boosting. This control strategy ensures that the output voltage is stable at the target value, while reducing switching losses and improving power conversion efficiency. In AC input mode, the signal switch is switched to position 1 to form a PWM rectifier bridge and adopts a dual closed-loop control strategy. The outer loop PI controller adjusts the output voltage, while the inner loop PI controller tracks the input current waveform to generate a precise PWM drive signal. This control method not only improves rectification efficiency but also can quickly adapt to load changes and input voltage fluctuations, ensuring the stability of the output voltage.

[0017] 3. This invention organically combines the front-end reconfigurable bridge arm circuit and the back-end inverter circuit, reducing redundant components, optimizing the circuit layout, making the entire system more compact, facilitating installation and integration in limited space, and contributing to the miniaturization and portability of the equipment.

[0018] Of course, any product implementing this invention does not necessarily need to achieve all of the advantages described above at the same time. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the converter circuit topology described in this invention; Figure 2 This is a flowchart of the control method for the converter circuit topology described in this invention; Figure 3 This is a schematic diagram of the SPWM control of the IGBT in AC-DC mode according to the present invention; Figure 4 This is a schematic diagram of the DC voltage simulation waveform under the AC-DC mode of the present invention; Figure 5 This is a schematic diagram of the SPWM control of the IGBT in DC-DC mode according to the present invention; Figure 6 This is a schematic diagram of the DC voltage simulation waveform in the DC-DC mode of this invention; Figure 7 This is a schematic diagram of SPWM modulation of the subsequent inverter circuit of the present invention; Figure 8 This is a schematic diagram of the AC voltage simulation waveform of the subsequent inverter circuit of this invention. Detailed Implementation

[0020] The technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this disclosure, and not all embodiments. Based on the embodiments of this disclosure, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this disclosure.

[0021] Example 1: Please see Figures 1-8 This invention provides a technical solution: an adaptive input converter circuit topology, comprising: An input detection module, located at the input port, is used to identify the AC or DC input type based on the amplitude change rate and frequency characteristics of the input voltage. The pre-amplifier reconfiguration arm circuit is used to switch between AC-DC rectification mode and DC-DC boost mode according to the AC or DC input type. When the input is AC, it switches to AC-DC rectification mode, and when the input is DC, it switches to DC-DC boost mode. The subsequent inverter circuit, cascaded after the preceding reconfiguration bridge arm circuit, is used to invert the DC power output from the preceding reconfiguration bridge arm circuit into stable AC power. The control module is used to dynamically modulate the switching signal according to the AC or DC input type, and to switch between AC-DC rectification mode and DC-DC boost mode by controlling the switching transistor to turn it on and off.

[0022] Regarding the technical solution of this embodiment, the input detection module uses Maxim Integrated's MAX9028 low-power comparator element, and the specific judgment principle is as follows: If the rate of change of the input voltage amplitude exceeds the threshold and exhibits periodic frequency characteristics, it is determined to be an AC input; If the rate of change of the input voltage amplitude remains below the threshold, it is determined to be a DC input.

[0023] Regarding the technical solution of this embodiment, the front-end reconfiguration bridge arm circuit includes four IGBT switching transistors Q1, Q2, Q3, Q4, a signal switch, and an inductor L1; The emitter of Q1 is connected to the collector of Q2 and the inductor; The collector of Q1 is connected to the collector of Q3; The emitter of Q3 is connected to the collector of Q4; When the input is DC, the emitter of Q2 is connected to the emitter of Q4; when the input is AC, it is connected to the collector of Q4.

[0024] Regarding the technical solution of this embodiment, the input terminal of the back-stage inverter circuit is connected to the output terminal of the reconfigurable bridge arm circuit. The back-stage inverter circuit includes four fully controlled IGBT switches, namely Q5, Q6, Q7, Q8, inductor L2, capacitor C2, and load R2. in: Collectors Q5 and Q6 are connected to the positive terminal of the DC bus; emitters Q7 and Q8 are connected to the negative terminal of the DC bus. The emitter and collector of Q5 are connected together and then connected to the positive terminal of the output. The emitter of Q6 and the collector of Q8 are connected together and then connected to the negative terminal of the output. Inductor L2 and capacitor C2 form an LC filter. Load R1 is connected to the AC output terminal through the LC filter to stabilize the output voltage at the load R1 terminal. It should be noted that the LC filter circuit composed of inductor L2 and capacitor C2 can effectively filter out high-frequency harmonic components in the output voltage of the inverter circuit. The inductor presents high impedance to high-frequency harmonics, hindering their passage, while the capacitor presents low impedance to high-frequency harmonics, providing a bypass path for the harmonics. After LC filtering, the voltage output to the load R2 is smoother and the waveform quality is higher. For example, in the power supply system of audio equipment, high-quality filtering can avoid harmonic interference to the audio signal and improve the fidelity of the audio output.

[0025] In summary, tightly integrating the downstream inverter circuit with the reconfigurable bridge arm circuit allows for a more compact circuit layout. This integrated design reduces the number of interconnecting lines, lowers wiring complexity and line losses, and improves the overall system efficiency. In space-constrained applications, such as portable emergency power supplies or vehicle-mounted charging devices, the compact circuit layout saves space and facilitates miniaturization and portability.

[0026] Regarding the technical solution of this embodiment, the signal switch has two operating positions: When position 1 is closed, the collector of Q2 is directly connected to the positive input terminal, forming an AC-DC full-bridge rectification mode; When position 2 is closed, the collector of Q2 is grounded, and Q1 and Q2 form a BOOST boost circuit using the freewheeling diode; Specifically, by switching the signal switch and controlling the on / off state of the four IGBTs, the circuit can intelligently identify and adapt to AC or DC input. When a DC input is detected, the signal switch switches to the corresponding position, Q3 and Q4 are turned off, and Q1, Q2, etc. are turned on according to a certain logic, forming a DC-DC boost circuit. When an AC input is detected, the signal switch switches to another position, and the four IGBTs form a PWM rectifier bridge to achieve AC-DC rectification. This adaptive capability allows a single circuit to be compatible with both AC and DC inputs, meeting the different power supply access requirements of multi-energy systems such as photovoltaic-storage-charging integrated power stations and mobile emergency power supplies, greatly improving its practicality.

[0027] In the technical solution of this embodiment, a load R1 is also provided between the front-stage reconfiguration bridge arm circuit and the rear-stage inverter circuit. A capacitor C1 is connected in parallel in front of the load R1 for filtering, and a diode D1 is connected after the load R1 to control the mutual impact between the front-stage reconfiguration bridge arm circuit and the rear-stage inverter circuit. Specifically, when the front-end reconfiguration bridge arm circuit outputs DC voltage, capacitor C1 can store electrical energy. When the load current changes or the front-end output experiences a brief fluctuation, capacitor C1 can release the stored electrical energy, playing a buffering role, maintaining the stability of the DC bus voltage, and ensuring that the subsequent inverter circuit can work normally.

[0028] In this embodiment, the anode of diode D1 is connected to the intersection of the positive terminals of inductor L1 and capacitor C1, and the cathode of diode D1 is connected to the positive terminal of the DC bus to block reverse current surges. Specifically, diode D1 is reverse-connected at the rear end of load R1. Diode D1 provides a unidirectional conductive path between the front and rear stage circuits, achieving electrical isolation. Under normal operation, it only allows current to flow from the front stage to the rear stage, preventing the reverse current generated by the rear stage inverter circuit from impacting the front stage reconfiguration bridge arm circuit. During the inverter process, if an abnormal situation occurs in the rear stage circuit causing the current to flow in reverse, diode D1 will be cut off, protecting the switching transistors and other devices in the front stage circuit from damage.

[0029] Regarding the technical solution of this embodiment, the control strategy of the control module in DC-DC boost mode is as follows: When the signal switch is switched to position 2, the collector of Q2 is grounded, turning off the switching transistors Q1, Q3 and Q4. The freewheeling diode of the switching transistor Q1 is turned on, forming a BOOST circuit. The DC voltage is boosted to the target value by dynamically adjusting the PWM duty cycle of Q2 using a PI controller. By dynamically adjusting the PWM duty cycle of Q2 using a PI controller, the duty cycle can be quickly adjusted based on the real-time difference between the output voltage and the target voltage, ensuring that the output voltage is precisely stabilized at the set value. The introduction of the PI controller effectively solves the problem of output voltage instability caused by factors such as load changes and input voltage fluctuations. For example, when the load suddenly increases, causing the output voltage to show a downward trend, the PI controller will detect this change and immediately increase the PWM duty cycle of Q2, thereby allowing inductor L1 to store more energy and release it later to maintain the stability of the output voltage. This dynamic adjustment mechanism greatly improves the steady-state performance and dynamic response speed of the system, ensuring that the system can operate stably under various operating conditions. In DC input mode, the freewheeling diode of Q1 acts as a general diode, forming a BOOST circuit with inductor L1, which reduces the voltage stress on Q1 during the turn-off period and reduces the switching losses of the switching transistors. At the same time, this control strategy enables each switching transistor to turn on and off at the appropriate time, avoiding unnecessary switching actions, further reducing switching losses and improving the efficiency of the entire DC-DC conversion process.

[0030] Regarding the technical solution of this embodiment, the control strategy of the control module in AC-DC rectification mode is as follows: When the signal switch is switched to position 1, the switching transistors Q1-Q4 form a PWM rectifier bridge. A dual closed-loop control strategy is adopted: the outer loop PI controller regulates the output voltage, and the inner loop PI controller tracks the input current waveform to generate PWM drive signals for the switching transistors Q1-Q4; The dual closed-loop control structure enables the system to have a fast dynamic response capability. When the load changes suddenly or the input voltage fluctuates, the outer loop PI controller adjusts quickly, and the inner loop PI controller tracks the input current in real time, so that the system can quickly recover to stability. In scenarios such as industrial automation equipment and data center UPS systems, it ensures a continuous and stable power supply. In AC input mode, the PWM rectifier bridge composed of four IGBTs can achieve more efficient rectification compared to a regular diode rectifier bridge.

[0031] The technical solution of the present invention will be further described below with reference to specific embodiments: Figure 1 In the given values, L1 = 5 × 10⁻³ H, L2 = 4.06 × 10⁻³ H, C1 = 4 × 10⁻³ F, C2 = 6.23 × 10⁻⁶ F, R1 = 50 Ω, and R2 = 100 Ω; When a DC input is detected, and a 100V DC voltage is input, the signal switch switches to... Figure 1 The simulated waveform of a 400V DC-DC output at position 2 is shown below. Figure 6 As shown; when an AC input is detected, an AC voltage with an amplitude of 220V and a frequency of 50Hz is input, and the signal switch switches to the position shown. Figure 1 The simulation waveform of position 1 achieving 400V DC output AC-DC voltage is shown below. Figure 4 As shown, since both AC-DC and DC-DC modes are set to output 400V DC, an AC voltage of 311V can be directly obtained through the subsequent inverter section, such as... Figure 8 As shown, different voltage outputs can also be achieved by changing the PID control of the entire topology.

[0032] Example 2: like Figure 2 As shown, the present invention provides a control method for an adaptive input converter circuit topology, comprising the following steps: S1. The input detection module identifies the AC or DC input type. If the input voltage amplitude change rate exceeds the threshold and has periodic frequency characteristics, it is determined to be AC ​​input; if the input voltage amplitude change rate is consistently below the threshold, it is determined to be DC input. S2. Determine the control mode and execute the corresponding control operation based on whether the input type is DC or AC. The control modes specifically include DC-DC boost mode and AC-DC rectification mode: S21. When in DC-DC boost mode, the control steps are as follows: (S21.1) Calculate the difference between the output voltage reference value V and the actual output voltage value V0; (S21.2) The calculated difference is processed by the proportional-integral controller to obtain the duty cycle signal for dynamically adjusting the switching transistor Q2; (S21.3) The duty cycle signal is directly fed into the PWM module in Simulink for comparison with the PWM signal used to control the Q2 switch, such as... Figure 5 As shown; S22. When in AC-DC rectification mode, the control steps are as follows: (S22.1) Calculate the difference between the output voltage reference value V and the actual output voltage value V0; (S22.2) The difference calculated in (S22.1) is processed by the first proportional-integral controller to obtain the reference deviation of the duty cycle; (S22.3) Multiply the input voltage by the gain and then multiply it by the reference deviation, and then compare it with the input current to calculate the difference; (S22.4) The difference calculated in (S22.3) is processed by the second proportional-integral controller and compared with the fundamental frequency to generate PWM control signals for the control switches Q1-Q4, such as... Figure 3 As shown; S3. Input the DC power output from the pre-stage reconfiguration bridge arm circuit into the subsequent inverter circuit to convert the DC power into stable AC power, as follows: (S31) Measure the voltage of the output load and calculate its root mean square (RMS). Compare the calculated RMS value with the ideal value to obtain the difference: (S32) Input the difference obtained in (S31) into the proportional-integral controller and multiply it with the sine wave to generate a modulation signal; (S33) The modulation signal obtained in (S32) is compared with the triangular carrier wave to generate an SPWM wave to achieve stable AC output, such as... Figure 7 As shown.

[0033] In summary, the converter circuit topology of this invention can identify the input power type in real time, and then change the topology by changing the closing or opening of several switches. This achieves the function of adapting a single topology to AC and DC inputs. Furthermore, the topology is obtained by cascading two parts, which allows for a stable AC output voltage while adapting to the input. The overall structure includes 8 IGBTs, along with voltage-regulating capacitors and inductors, and diodes that limit the current direction. When the input is detected as DC, a stable AC output is achieved through boost and inversion. When the input is detected as AC, the AC input is boosted through rectification and inversion to obtain the target AC voltage. The entire system change is achieved solely through the control strategy of the switches, significantly reducing the system complexity and cost.

[0034] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0035] For those skilled in the art, the specific meaning of the above terms in this invention can be understood according to the specific circumstances. When an element is referred to as being "assembled on," "mounted on," "fixed to," or "set on" another element, it may be directly on the other element or there may be an intermediate element present. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be an intermediate element present. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible embodiments.

[0036] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

[0037] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this disclosure. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

Claims

1. An adaptive input converter circuit topology, characterized in that, include: The pre-amplifier reconfiguration arm circuit is used to switch between AC-DC rectification mode and DC-DC boost mode according to the AC or DC input type. When the input is AC, it switches to AC-DC rectification mode, and when the input is DC, it switches to DC-DC boost mode. The subsequent inverter circuit, cascaded after the preceding reconfiguration bridge arm circuit, is used to invert the DC power output from the preceding reconfiguration bridge arm circuit into stable AC power. The control module is used to dynamically modulate the switching signal according to the AC or DC input type, and to switch between AC-DC rectification mode and DC-DC boost mode by controlling the switching transistor to turn it on and off.

2. The adaptive input converter circuit topology according to claim 1, characterized in that: It also includes an input detection module, located at the input port, used to identify the AC or DC input type based on the amplitude change rate and frequency characteristics of the input voltage. The specific judgment principle is as follows: If the rate of change of the input voltage amplitude exceeds the threshold and exhibits periodic frequency characteristics, it is determined to be an AC input; If the rate of change of the input voltage amplitude remains below the threshold, it is determined to be a DC input.

3. The adaptive input converter circuit topology according to claim 2, characterized in that: The pre-reconfiguration bridge arm circuit includes four IGBT switches Q1, Q2, Q3, Q4, a signal switch, and an inductor L1. in: The emitter of Q1 is connected to the collector of Q2 and the inductor; The collector of Q1 is connected to the collector of Q3; The emitter of Q3 is connected to the collector of Q4; When the input is DC, the emitter of Q2 is connected to the emitter of Q4; when the input is AC, it is connected to the collector of Q4.

4. The adaptive input converter circuit topology according to claim 3, characterized in that: The input terminal of the subsequent inverter circuit is connected to the output terminal of the reconfigurable bridge arm circuit. The subsequent inverter circuit includes four fully controlled IGBT switches, namely Q5, Q6, Q7, Q8, inductor L2, capacitor C2, and load R2. in: Collectors Q5 and Q6 are connected to the positive terminal of the DC bus; emitters Q7 and Q8 are connected to the negative terminal of the DC bus. The emitter and collector of Q5 are connected together and then connected to the positive terminal of the output. The emitter of Q6 and the collector of Q8 are connected together and then connected to the negative terminal of the output. Inductor L2 and capacitor C2 form an LC filter. Load R1 is connected to the AC output terminal through the LC filter to stabilize the output voltage at the load R1 terminal.

5. The adaptive input converter circuit topology according to claim 4, characterized in that: The signal switch has two operating positions: When position 1 is closed, the collector of Q2 is directly connected to the positive input terminal, forming an AC-DC full-bridge rectification mode; When position 2 is closed, the collector of Q2 is grounded, and Q1 and Q2 form a BOOST boost circuit using the freewheeling diode.

6. The adaptive input converter circuit topology according to claim 5, characterized in that: A load R1 is also provided between the front-stage reconfiguration bridge arm circuit and the rear-stage inverter circuit. A capacitor C1 is connected in parallel in front of the load R1 for filtering, and a diode D1 is connected after the load R1 to control the mutual impact between the front-stage reconfiguration bridge arm circuit and the rear-stage inverter circuit.

7. The adaptive input converter circuit topology according to claim 6, characterized in that: The anode of diode D1 is connected to the intersection of the positive terminals of inductor L1 and capacitor C1, and the cathode of diode D1 is connected to the positive terminal of the DC bus to block reverse current surges.

8. The adaptive input converter circuit topology according to claim 1, characterized in that: The control strategy of the control module in DC-DC boost mode is as follows: When the signal switch is switched to position 2, the collector of Q2 is grounded, turning off the switching transistors Q1, Q3 and Q4. The freewheeling diode of the switching transistor Q1 is turned on, forming a BOOST circuit. The DC voltage is boosted to the target value by dynamically adjusting the PWM duty cycle of Q2 using a PI controller.

9. The adaptive input converter circuit topology according to claim 8, characterized in that: The control strategy of the control module in AC-DC rectification mode is as follows: When the signal switch is switched to position 1, the switching transistors Q1-Q4 form a PWM rectifier bridge. A dual closed-loop control strategy is adopted: the outer loop PI controller adjusts the output voltage, and the inner loop PI controller tracks the input current waveform to generate PWM drive signals for the switching transistors Q1-Q4.

10. A control method for an adaptive input converter circuit topology, characterized in that, Includes the following steps: S1. The input detection module identifies the AC or DC input type. If the input voltage amplitude change rate exceeds the threshold and has periodic frequency characteristics, it is determined to be AC ​​input; if the input voltage amplitude change rate is consistently below the threshold, it is determined to be DC input. S2. Determine the control mode and execute the corresponding control operation based on whether the input type is DC or AC. The control modes specifically include DC-DC boost mode and AC-DC rectification mode: S21. When in DC-DC boost mode, the control steps are as follows: (S21.1) Calculate the difference between the output voltage reference value V and the actual output voltage value V0; (S21.2) The calculated difference is processed by the proportional-integral controller to obtain the duty cycle signal for dynamically adjusting the switching transistor Q2; (S21.3) The duty cycle signal is directly fed into the PWM module in Simulink for comparison with the PWM signal used to control the Q2 switch; S22. When in AC-DC rectification mode, the control steps are as follows: (S22.1) Calculate the difference between the output voltage reference value V and the actual output voltage value V0; (S22.2) The difference calculated in (S22.1) is processed by the first proportional-integral controller to obtain the reference deviation of the duty cycle; (S22.3) Multiply the input voltage by the gain and then multiply it by the reference deviation, and then compare it with the input current to calculate the difference; (S22.4) The difference calculated in (S22.3) is processed by the second proportional-integral controller and compared with the fundamental wave to generate PWM control signals for the control switches Q1-Q4; S3. Input the DC power output from the pre-stage reconfiguration bridge arm circuit into the subsequent inverter circuit to convert the DC power into stable AC power, as follows: (S31) Measure the voltage of the output load and calculate its root mean square (RMS). Compare the calculated RMS value with the ideal value to obtain the difference: (S32) Input the difference obtained in (S31) into the proportional-integral controller and multiply it with the sine wave to generate a modulation signal; (S33) The modulation signal obtained in (S32) is compared with the triangular carrier wave to generate an SPWM wave to achieve stable AC output.

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