Digital control mode switching method and system

Abstract

The invention discloses a digital control mode switching method and a digital control mode switching system, and belongs to the technical field of power electronics. Triggering to enter a single-voltage loop operation channel; obtaining a single-loop modulation basic quantity based on the output voltage signal, a preset voltage reference value and a pre-obtained voltage integral initial value; obtaining a switching value control signal based on the single-loop modulation basic quantity, the output voltage signal and the input voltage signal, so as to control the conduction state of the main circuit module based on the switching value control signal; and assigning an inner ring integral initial value based on the single-ring modulation basic quantity, assigning an inner ring current reference value based on the output current signal, and assigning an outer ring integral initial value based on the output current signal. According to the digital control mode switching method and system disclosed by the invention, the stability of output voltage under light load or no load is ensured by realizing stable switching of operation channels.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of power electronics, in particular to a digital control mode switching method and system. BACKGROUND

[0002] Three-phase step-down power factor correction (PFC) technology has many advantages such as controllable power factor, output voltage lower than input voltage, small current harmonic, full-load start without additional anti-starting current circuit, and output short-circuit support. It is a three-phase power factor correction scheme with excellent performance. At present, in order to achieve simple and reliable control, an indirect current control strategy is generally used. This control strategy does not need to collect input current components, but only needs to collect three-phase input voltage, output voltage and output current to realize three-phase power factor correction function. The control loop usually adopts a double-loop control scheme of output voltage outer loop and current inner loop. The control quantity generated by the loop is combined with the modulation requirement of three-phase input voltage, and is controlled through space vector modulation (SVM), so as to finally realize power factor correction of input current.

[0003] Among them, the indirect current control strategy completes control adjustment by sampling three-phase input voltage and combining the sampling data of output voltage and output current. In the continuous inductance current condition, since the current sampling signal is stable at this time, the control is easy to realize, and the output voltage ripple is small, so the control adjustment performs well. However, when the device is in an output no-load or light-load condition, the inductance current will be discontinuous or even sometimes non-existent. At this time, the current feedback quantity is too small, which is easily disturbed by circuit parasitic parameters, and thus the control of the control loop (such as current inner loop) is difficult to stabilize, which often causes the problem of low-frequency ripple or even oscillation of output voltage. Especially in the condition of high input voltage and low output voltage, this instability phenomenon will be further intensified, and it is often necessary to continuously weaken the control effect of the control loop and repeatedly adjust the control parameters to restore the relatively stable state of the output voltage. SUMMARY

[0004] The present application provides a digital control mode switching method and system, which can solve the technical problem of unstable output voltage, easy to produce low-frequency ripple or oscillation when output no-load or light-load condition occurs in the prior art, and ensures the stability of output voltage under light load or no load by realizing smooth switching of operation channel.

[0005] The present application provides a digital control mode switching method applied to a digital control mode switching system, which is electrically connected to a main circuit module and comprises: The input voltage signal, the output voltage signal and the output current signal of the main circuit module are acquired in real time; When it is determined that the preset light load determination condition is met based on the output current signal, a single voltage loop operation channel is triggered to enter, and in each operation period: The single voltage loop proportional integral operation is performed based on the output voltage signal, a preset voltage reference value and a pre-acquired voltage integral initial value to acquire a single loop modulation basis quantity; The switching quantity control signal is acquired based on the single loop modulation basis quantity, the output voltage signal and the input voltage signal, so that the output voltage of the main circuit module is regulated based on the switching quantity control signal; The double loop synchronous assignment action is performed on the double loop operation channel in parallel: the assignment of the inner loop integral initial value is performed based on the single loop modulation basis quantity, the assignment of the inner loop current reference value is performed based on the output current signal, and the assignment of the outer loop integral initial value is performed based on the output current signal, so that the switching quantity control signal is output based on the inner loop integral initial value, the inner loop current reference value and the outer loop integral initial value when the switching to the double loop operation channel is triggered.

[0006] The digital control mode switching method provided by the application acquires the input voltage, the output voltage and the output current signal of the main circuit in real time, determines the control condition based on the output current signal to control the switching operation channel, and cuts into the single voltage loop control when the load is light or empty, so that the output voltage low-frequency ripple and oscillation problem caused by the fact that the current inner loop is easily disturbed due to the discontinuous inductance current and small feedback quantity is avoided; in the single voltage loop operation channel, the single loop modulation basis quantity is acquired through proportional integral operation to generate the switching quantity control signal, and the assignment of the inner loop integral initial value, the inner loop current reference value and the outer loop integral initial value of the double loop operation channel is performed in parallel, so that the integral initial value remains unchanged when the switching to the double loop operation channel is performed subsequently, which lays a foundation for the power factor correction when the load is heavy, thereby ensuring that the control parameters are seamlessly connected when the switching to the double loop operation channel is performed subsequently, smooth switching is realized, and the output voltage of the main circuit module is not affected.

[0007] Further, the single voltage loop proportional integral operation based on the output voltage signal, the preset voltage reference value and the pre-acquired voltage integral initial value to acquire the single loop modulation basis quantity comprises: The voltage error signal is acquired based on the output voltage signal and the preset voltage reference value; The single loop modulation basis quantity is acquired through the single voltage loop proportional integral operation based on the voltage error signal and the pre-acquired voltage integral initial value.

[0008] In the scheme, the single-loop modulation basis quantity can accurately reflect the deviation of the output voltage from the reference value by accurately calculating the voltage error and combining the integral initial value for operation, and then generate accurate switching quantity control signals, effectively suppress the voltage fluctuation at light load or no load, and further improve the stability of the output voltage.

[0009] Further, the switching quantity control signal is obtained based on the single-loop modulation basis quantity, the output voltage signal and the input voltage signal, and the output voltage of the main circuit module is regulated based on the switching quantity control signal, including: The current phase sector is obtained based on the input voltage signal and the preset space vector sector vector diagram of the main circuit module; The corresponding basic current vector is obtained based on the current phase sector; The corresponding control switch tube is obtained based on the corresponding basic current vector, and the corresponding switch tube preset period is obtained based on the corresponding control switch tube; The input phase voltage peak value is obtained based on the input voltage signal; The switching tube action time is obtained by conducting switching time operation based on the input voltage signal, the output voltage signal, the single-loop modulation basis quantity, the input phase voltage peak value and the corresponding switch tube preset period; The switching quantity control signal is obtained based on the switching tube action time and the corresponding control switch tube, and the output voltage of the main circuit module is regulated based on the switching quantity control signal.

[0010] In the scheme, the sector division and vector selection are combined with the phase characteristics of the three-phase input voltage, so that the switching tube conduction time calculation can adapt to the phase change of the grid voltage, and the generated switching quantity control signal is synchronized with the grid voltage. While ensuring the stability of the output voltage at light load or no load, the current distortion rate of the main circuit module is reduced, and the compatibility and reliability of the main circuit module operation are improved.

[0011] Further, it further includes: The real-time input voltage signal, the real-time output voltage signal and the real-time output current signal of the main circuit module are obtained; When it is determined that the preset heavy load determination condition is met based on the real-time output current signal, the switching to the double-loop operation channel is triggered; At the moment of triggering the switching of the double-loop operation channel, the instantaneous double-loop operation action is performed: The instantaneous error signal is obtained based on the inner loop current reference value and the real-time output current signal; The current inner loop proportional integral operation is performed based on the instantaneous error signal and the inner loop integral initial value, and the instantaneous double-loop modulation basis quantity is obtained; The switching quantity control signal is acquired based on the instantaneous double-loop modulation basis quantity, the real-time input voltage signal and the real-time output voltage signal, so that the output voltage of the main circuit module is regulated based on the switching quantity control signal.

[0012] In the above scheme, the parallel assignment step in the operation process realizes instantaneous operation at the switching moment, the parameters pre-assigned during single-loop operation are used to avoid sudden changes of the reference current and the modulation basis quantity during the switching process, to prevent the system from generating oscillation, to realize smooth transition from single-loop to double-loop, and to quickly respond to power control requirements during heavy load.

[0013] Further, at the moment of triggering the double-loop operation channel, after the instantaneous double-loop operation action step is performed, the method further comprises, in each operation period: real-time acquisition of a current input voltage signal, a current output voltage signal and a current output current signal; double-loop integral operation based on the current output voltage signal, the current output current signal, a preset voltage reference value, an instantaneous double-loop modulation basis quantity and an outer-loop integral initial value, to acquire a double-loop modulation basis quantity; acquisition of a switching quantity control signal based on the double-loop modulation basis quantity, the current output voltage signal and the current input voltage signal, to regulate the output voltage of the main circuit module based on the switching quantity control signal; parallel execution of a single-loop synchronous assignment action: assignment of a voltage integral initial value of a single voltage loop based on the double-loop modulation basis quantity; assignment of a current inner-loop integral initial value of a voltage outer loop based on the double-loop modulation basis quantity.

[0014] In the above scheme, the double-loop integral operation ensures that the input current is in phase with the voltage during heavy load, improves the power factor and reduces the current distortion rate; at the same time, the synchronous assignment of the single-loop integral initial value during double-loop operation provides a parameter connection basis for subsequent switching back to the single voltage loop, ensures the smoothness of switching in the full load range, and takes into account the power quality during heavy load and the stability of load switching.

[0015] Further, the double-loop integral operation based on the current output voltage signal, the current output current signal, the preset voltage reference value, the instantaneous double-loop modulation basis quantity and the outer-loop integral initial value to acquire the double-loop modulation basis quantity comprises: acquisition of a current voltage error signal based on the current output voltage signal and the preset voltage reference value; voltage outer-loop modulation operation based on the current voltage error signal and the outer-loop integral initial value to acquire a current inner-loop reference value; acquisition of a current error signal based on the current inner-loop reference value and the current output current signal; Based on the current error signal and the initial value of the current inner loop integral, the proportional-integral operation of the current inner loop is performed to obtain the basic quantity of the dual-loop modulation.

[0016] In the above scheme, the current voltage error signal is first obtained by comparing the current output voltage signal with the preset voltage reference value. Then, the voltage outer loop is modulated by combining the initial value of the outer loop integral to obtain the current inner loop reference value. Next, the current error signal is obtained by combining the current inner loop reference value with the current output current signal. The current inner loop proportional integral is then performed by combining the instantaneous dual-loop modulation base quantity. This enables the voltage outer loop to accurately stabilize the output voltage and the current inner loop to quickly track the reference current, further improving the stability of the output voltage and the sinusoidal nature of the input current under heavy load, optimizing the power factor correction effect, and reducing grid harmonic pollution.

[0017] Furthermore, the real-time acquisition of the input voltage signal, output voltage signal, and output current signal of the main circuit module includes: The main circuit input voltage signal is acquired in real time, and the main circuit input voltage signal is processed by differential operational amplifier to obtain the input voltage signal. The main circuit output voltage signal is acquired in real time, and the main circuit output voltage signal is processed by differential operational amplifier to obtain the output voltage signal. The main circuit output current signal is acquired in real time, and the main circuit output current signal is processed by differential operational amplifier to obtain the output current signal.

[0018] In the above scheme, the high voltage and high current signals of the main circuit module are scaled proportionally to signals that can be processed by the digital controller through differential operational amplifier processing. At the same time, the influence of parasitic parameters and external interference on the sampling signal is suppressed, thereby improving the accuracy and stability of the sampling signal.

[0019] This invention provides a digital control mode switching system for implementing the aforementioned digital control mode switching method, comprising: The signal acquisition module is used to acquire the input voltage signal, output voltage signal, and output current signal of the main circuit module in real time. The digital control module is used to trigger entry into the single-voltage loop operation channel when the output current signal determines that a preset light no-load judgment condition is met. Within each operation cycle, it performs single-voltage loop proportional-integral operation based on the output voltage signal, a preset voltage reference value, and a pre-acquired initial voltage integral value to obtain a single-loop modulation base quantity; it obtains a switching control signal based on the single-loop modulation base quantity, the output voltage signal, and the input voltage signal to regulate the output voltage of the main circuit module based on the switching control signal; and it performs a dual-loop synchronous assignment operation on the dual-loop operation channel in parallel: assigning an initial value for the inner loop integral based on the single-loop modulation base quantity, assigning an initial value for the inner loop current reference based on the output current signal, and assigning an initial value for the outer loop integral based on the output current signal, so that when switching to the dual-loop operation channel is triggered, the switching control signal is output based on the initial value for the inner loop integral, the initial value for the inner loop current reference, and the initial value for the outer loop integral.

[0020] Furthermore, the signal acquisition module includes an input voltage acquisition submodule, an output voltage acquisition submodule, and an output current acquisition submodule, wherein: The input voltage acquisition submodule is used to acquire the main circuit input voltage signal in real time, and to perform differential operational amplifier processing on the main circuit input voltage signal to acquire the input voltage signal. The output voltage acquisition submodule is used to acquire the main circuit output voltage signal in real time, and to perform differential operational amplifier processing on the main circuit output voltage signal to acquire the output voltage signal. The output current acquisition submodule is used to acquire the main circuit output current signal in real time, and to perform differential operational amplifier processing on the main circuit output current signal to obtain the output current signal.

[0021] Furthermore, the digital control module is also used to: acquire real-time input voltage signal, real-time output voltage signal, and real-time output current signal from the signal acquisition module; when the real-time output current signal determines that a preset overload judgment condition is met, trigger a switch to the dual-loop operation channel; at the instant the dual-loop operation channel is triggered, perform an instantaneous dual-loop operation: acquire an instantaneous error signal based on the inner loop current reference value and the real-time output current signal; perform a current inner loop proportional-integral operation based on the instantaneous error signal and the inner loop integral initial value to acquire the instantaneous dual-loop modulation base quantity; acquire a switching control signal based on the instantaneous dual-loop modulation base quantity, the real-time input voltage signal, and the real-time output voltage signal, so as to regulate the output voltage of the main circuit module based on the switching control signal.

[0022] This invention provides a digital control mode switching method, or system, which achieves adaptive mode switching by judging the output current, switching to a single voltage loop operation channel under light no-load conditions and switching to a dual-loop operation channel under heavy load conditions. Combined with differential operational amplifier processing of signal acquisition, hierarchical execution of proportional-integral operations, cross-mode parameter synchronization assignment, and preset space vector sector vector diagram, it realizes the generation of precise switching control signals. It can comprehensively solve the technical problems of low-frequency ripple and oscillation of output voltage caused by discontinuous inductor current and easy interference of current feedback in three-phase buck power factor correction (PFC) under light load or no-load conditions. At the same time, it ensures that the input current and voltage are in phase under heavy load conditions, improves the power factor, and reduces the current distortion rate. By synchronously assigning bidirectional parameters during single-loop and dual-loop operation, smooth switching of control modes across the entire load range is achieved, avoiding system oscillations and parameter mutations during the switching process. Through precise signal processing and computational logic, the stability of output voltage and power quality are improved, simplifying the loop control difficulty under light loads. Stable operation across the entire load range can be achieved without repeated parameter adjustments, meeting the stability, power quality, and load adaptability requirements of three-phase step-down PFC in industrial power supplies, new energy converters, and other scenarios. Attached Figure Description

[0023] To more clearly illustrate the technical solution of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0024] Figure 1 This embodiment provides a schematic diagram of a digital control mode switching method; Figure 2 This embodiment provides a schematic diagram of the main circuit of a three-phase step-down PFC. Figure 3 This embodiment provides a schematic diagram of a preset spatial vector sector vector map; Figure 4 This embodiment provides a schematic diagram of a dual-channel computing architecture; Figure 5 This embodiment provides a schematic diagram of a three-phase step-down PFC digital control device. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0026] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0027] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0028] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0029] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0030] In the description of the embodiments of this application, the term "multiple" refers to two or more (including two), similarly, "multiple sets" refers to two or more (including two sets), and "multiple pieces" refers to two or more (including two pieces).

[0031] In the description of the embodiments of this application, unless otherwise expressly specified and limited, technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0032] Example 1: This embodiment provides a digital control mode switching method, applied to a digital control mode switching system, wherein the digital control mode switching system is electrically connected to the main circuit module, such as... Figure 1 As shown, it includes: S1. Real-time acquisition of the input voltage signal, output voltage signal, and output current signal of the main circuit module; S2. When the output current signal is determined to meet the preset light no-load determination condition, the single voltage loop operation channel is triggered. In each operation cycle: S3. Perform single-loop proportional-integral calculation based on the output voltage signal, the preset voltage reference value, and the pre-acquired initial voltage integral value to obtain the single-loop modulation base quantity; S4. Obtain a switching control signal based on the single-loop modulation base quantity, the output voltage signal, and the input voltage signal, and regulate the output voltage of the main circuit module based on the switching control signal; S5. Perform parallel dual-loop synchronous assignment on the dual-loop operation channel: assign the initial value of the inner loop integral based on the single-loop modulation base quantity, assign the reference value of the inner loop current based on the output current signal, and assign the initial value of the outer loop integral based on the output current signal, so that when the switch to the dual-loop operation channel is triggered, the switching control signal is output based on the initial value of the inner loop integral, the reference value of the inner loop current, and the initial value of the outer loop integral.

[0033] This embodiment provides a digital control mode switching method to address the issue of unstable output under light load or no-load conditions in the control of a three-phase step-down PFC, which frequently leads to low-frequency ripple or oscillation in the output voltage. Specifically, this embodiment uses... Figure 2 The main circuit of the three-phase step-down PFC shown is used as an example to illustrate the main circuit module. Figure 2As shown, the main circuit input side of the three-phase step-down PFC is the three-phase input terminals corresponding to the three-phase AC input voltages Va, Vb, and Vc, providing AC power to the main circuit. The three-phase input terminals are electrically connected to the switching transistor module through an input filter unit composed of input-side inductors La, Lb, and Lc, and input-side filter capacitors Ca, Cb, and Cc. The switching transistor module consists of a three-phase full-bridge topology composed of six power switches S1, S2, S3, S4, S5, and S6, with each power switch connected in reverse parallel to a freewheeling diode, corresponding to a total of six freewheeling diodes D1, D2, D3, D4, D5, and D6. The freewheeling diodes are used for... The circuit provides a freewheeling path for the inductor current when the power switch is turned off, preventing damage to the power switch due to voltage spikes. A midpoint clamping diode Do is connected in parallel across the switching module. The output of the switching module is connected to a filter energy storage module, which includes output inductors Lp and Ln and an output filter capacitor Co. This module is used to suppress current ripple, temporarily store and transfer energy, and filter out high-frequency ripple in the output voltage to ensure stable output voltage. The output capacitor Co is connected in parallel across the filter energy storage module. The load Load is connected in parallel across the output capacitor Co. The load is the power terminal of the main circuit and receives a stable DC voltage Vo after PFC correction. The main circuit also includes a sampling element, with a sampling resistor Ro connected in series with the output inductor Ln, used to acquire the output inductor current signal in real time. The overall circuit converts the three-phase AC input into a stable DC output through the orderly switching of the switching transistors, combined with the filtering and energy storage functions of the inductors and capacitors. At the same time, it works with the digital control module to achieve power factor correction and stable control across the entire load range.

[0034] In practical implementation, the control logic of the three-phase step-down PFC is mainly completed by the digital control section. To address the issue of unstable output voltage and low-frequency ripple under no-load or light-load conditions, this embodiment establishes a digital control mode switching system. Under light-load or no-load conditions, the load current (represented by the output current signal in this embodiment) is relatively small. When the output current signal is less than a preset value, it is determined that a preset light no-load condition is met, triggering entry into the second operation channel (single voltage loop operation channel). The second operation channel uses single voltage loop control logic. When the load current gradually increases to a fixed value, it is determined that a preset heavy-load condition is met, triggering a rapid switch to the first operation channel. The first operation channel uses voltage outer loop and current inner loop control logic, i.e., the dual-loop operation channel. During operation in the second operation channel, parallel assignment processing is performed on the integrator and related variables of the first channel. This ensures a smooth switching of the control system when switching to the first operation channel, preventing system oscillations and thus ensuring stable output voltage under no-load or light-load conditions, while also maintaining the input power factor and input current distortion content under certain load conditions.

[0035] In the specific implementation process, this embodiment uses a digital control mode switching system to acquire the input voltages Va, Vb, and Vc of the main circuit module through the three-phase input terminals to obtain the input voltage signal; and acquires the output inductor current signal passing through the sampling resistor Ro. The output current signal is obtained; the output voltage signal is obtained by acquiring the voltage across the output capacitor Co.

[0036] Optionally, step S3 includes: The voltage error signal is obtained based on the output voltage signal and the preset voltage reference value; Based on the voltage error signal and the pre-acquired initial voltage integral value, a single-voltage loop proportional-integral operation is performed to obtain the single-loop modulation base quantity.

[0037] In the specific implementation process, after receiving the input current signal, the single voltage loop operation channel calculates the difference between it and the preset voltage reference value to obtain the voltage error signal. This voltage error signal is then sent to the PI regulator stage, where it is combined with the pre-acquired initial voltage integral value to perform single voltage loop proportional-integral calculation to obtain the single-loop modulation base quantity.

[0038] Specifically, the digital implementation process of the PI controller used in this embodiment is as described in the following formula: ; In the formula: The current error input is e(k-1), and the previous error input is e(k-1). In this embodiment, the calculated voltage error signal is used as the error input. T is the operation cycle. The time constant of the integral term, The time constant of the differential term, , To control the parameters that need to be tuned; The sum of the previous k operations is the initial value of the voltage integral to be acquired; u(k) is the output value of the current PI regulator operation (in the single voltage loop operation channel, this output value corresponds to the single loop modulation base quantity). This is the proportionality coefficient. The integral coefficient is... The differential coefficients are... , and These are the control parameters that ultimately need to be tuned. In actual control, to simplify calculations, the derivative term is usually set to 0. The digital implementation can be simplified to a PI controller, as shown in the simplified equation below: ; , These are the parameters that need to be tuned for PI control. During loop switching, to avoid repeated switching, some hysteresis processing is needed for judging the output current signal. When the output current signal is greater than a preset value... When the output current signal is less than the preset value, the dual-loop operation channel is entered. When entering the single-voltage loop operation channel, the current switching hysteresis is... .

[0039] Optionally, step S4 includes: The current phase sector is obtained based on the input voltage signal and the preset space vector sector vector diagram of the main circuit module; Obtain the corresponding basic current vector based on the current phase sector; The corresponding control switch is obtained based on the corresponding basic current vector, and the preset period of the corresponding switch is obtained based on the corresponding control switch. The peak value of the input phase voltage is obtained based on the input voltage signal; Based on the input voltage signal, output voltage signal, single-loop modulation base quantity, input phase voltage peak value and corresponding preset period of the switch tube, the conduction switching time is calculated to obtain the switching tube's operating time. Based on the operating time of the switching transistor and the corresponding control switching transistor, a switching control signal is obtained to regulate the output voltage of the main circuit module.

[0040] In the specific implementation process, the SVPWM modulation module multiplies the loop operation result with the input voltage signal to obtain the modulation amount of the output duty cycle signal. Since the three-phase BUCK (step-down converter topology) PFC requires different sectors to control the switches, Space Vector Pulse Width Modulation (SVPWM) vector calculations are performed on different sectors based on the vector synthesis diagram to obtain the control signal corresponding to each sector. The generated duty cycle control signal controls the on / off state of the corresponding switch. In different sectors, the command current I at any given time within the current sector is obtained by combining two adjacent non-zero current vectors and one zero current vector. The vector synthesis diagram on which this is based, i.e., the preset space vector sector vector diagram, is shown below. Figure 3 As shown, this includes sectors 1 to 12, corresponding to command currents. , , , , and Command current Corresponding to switching transistors S1 and S2, Corresponding to switching transistors S2 and S3, Corresponding to switching transistors S3 and S4, Corresponding to switching transistors S4 and S5, Corresponding to switching transistors S5 and S6, The corresponding switching transistors are S1 and S6.

[0041] In the specific calculation process, taking sector 1 as an example, when the phase of the input voltage signal is located in sector 1, that is, when the current phase sector is sector 1, the corresponding basic current vector is obtained as follows: and Vector The corresponding switches are S1 and S2, vector The corresponding switches are S1 and S6, meaning the corresponding control switches are S1, S2, and S6. Therefore, the main switch control corresponds to S1, S2, and S6. Based on the final vector calculation and the loop adjustment, the action times of S1, S2, and S6 are: in the formula The on-time of switch S1 The on-time of switch S6. The on-time of switch S2 , and Together they constitute the operating time of the aforementioned switching transistor; This represents the instantaneous value of the phase voltage of the three-phase input voltage signal. This represents the peak value of the input phase voltage. The output voltage signal is m, which is the loop output (in the single voltage loop operation channel, this loop output is the single loop modulation basic quantity). A preset period is set for the corresponding switching transistor. Vector synthesis for other sectors is similar to that for sector 1.

[0042] Optional, also includes: Acquire the real-time input voltage signal, real-time output voltage signal, and real-time output current signal of the main circuit module; When the preset overload determination condition is met based on the real-time output current signal, the switch to the dual-ring operation channel is triggered. At the instant the dual-ring operation channel is switched, a momentary dual-ring operation is performed: The instantaneous error signal is obtained based on the inner loop current reference value and the real-time output current signal; Based on the instantaneous error signal and the initial value of the inner loop integral, the current inner loop proportional-integral operation is performed to obtain the instantaneous dual-loop modulation basic quantity; Based on the instantaneous dual-loop modulation base quantity, real-time input voltage signal, and real-time output voltage signal, a switching control signal is obtained to regulate the output voltage of the main circuit module.

[0043] In practical implementation, this embodiment lacks an inner current loop, resulting in weak current control. When the load is unloaded or very light, the power factor and total harmonic distortion (THD) are primarily determined by the input filter unit of the main circuit and some parasitic parameters. At this time, ensuring output voltage stability is sufficient. When the load increases, to ensure a smooth transition to dual-loop operation, the variables of the dual-loop operation channel need to be processed in each operating cycle during single-voltage loop operation, as described in step S5. Specifically, the variables processed are as follows: the integral result of the single-voltage loop, i.e., the single-loop modulation base value, is assigned to the initial value of the inner loop integral value of the current inner loop controlled by the dual-loop operation channel; the output current signal at this time... The instantaneous value corresponding to the digital quantity is assigned to the initial value of the outer loop integral of the voltage outer loop, and the output current signal is assigned to the inner loop current reference value of the input reference of the current inner loop. When the sampled output current signal reaches a certain specific value, the control will quickly switch to the first operation channel for dual-loop control. Since the integral quantity of the PI regulator in the current inner loop has been initialized in advance, the modulation of the input voltage at this time is mainly determined by the integral quantity of the PI regulator and will not change significantly, ensuring a smooth switching. At the same time, the integral quantity of the PI regulator in the voltage outer loop has also been initialized in advance, so the initial calculation result is basically the same as the load current, and there will be no fluctuations. The overall switching will be very smooth. After the switching is completed, the control of the dual-loop operation channel will begin.

[0044] Optionally, after executing the instantaneous dual-ring operation step at the instant of triggering the switching of the dual-ring operation channel, the method further includes, within each operation cycle: Real-time acquisition of current input voltage signal, current output voltage signal, and current output current signal; Based on the current output voltage signal, current output current signal, preset voltage reference value, instantaneous dual-loop modulation basic quantity and outer loop integration initial value, perform dual-loop integration calculation to obtain the dual-loop modulation basic quantity; Based on the dual-loop modulation base quantity, the current output voltage signal, and the current input voltage signal, a switching control signal is obtained to regulate the output voltage of the main circuit module based on the switching control signal. Parallel execution of single-loop synchronous assignment action: Assigning initial values ​​of voltage integral to a single voltage loop based on the dual-loop modulation base quantity; The initial value of the current inner loop integral is assigned to the voltage outer loop based on the aforementioned dual-loop modulation fundamental quantity.

[0045] Optionally, the step of performing dual-loop integration calculation based on the current output voltage signal, the current output current signal, the preset voltage reference value, the instantaneous dual-loop modulation base quantity, and the initial value of the outer loop integral to obtain the dual-loop modulation base quantity includes: The current voltage error signal is obtained based on the current output voltage signal and the preset voltage reference value; Based on the current voltage error signal and the initial value of the outer loop integral, voltage outer loop modulation calculation is performed to obtain the current inner loop reference value; The current error signal is obtained based on the current inner loop reference value and the current output current signal; Based on the current error signal and the initial value of the current inner loop integral, the proportional-integral operation of the current inner loop is performed to obtain the basic quantity of the dual-loop modulation.

[0046] In the specific implementation process, after entering the dual-loop control, in each operation cycle, the voltage outer loop of the dual-loop operation channel controls the current output voltage signal Vo and then subtracts it from the preset voltage reference value Vo_ref. The resulting current voltage error signal V_error is sent to the PI regulator stage of the voltage outer loop for calculation. The result of the voltage outer loop PI regulator calculation is used as the reference value Iref of the current inner loop. Then, Iref is compared with the current output current signal ( The feedback value is subtracted from the input current, and the difference is sent to the PI regulator of the inner current loop. Based on the initial integral value of the PI regulator of the inner current loop (such as the initial integral value of the inner current loop after instantaneous switching, and the integral value of the previous multiple operation cycles after multiple operation cycles), the proportional-integral operation of the inner current loop is performed to obtain the dual-loop modulation base quantity. Finally, the dual-loop modulation base quantity output by the inner current loop PI regulator is multiplied by the AC grid voltage, i.e., the current input current signal, and normalized to become the modulation wave signal, which is input to the SVPWM modulation module. The output PWM switching signal (i.e., the switching control signal) controls the rectifier bridge arm of the main circuit to conduct, realizing the input current power factor correction function. During the operation of the dual-loop operation channel, in order to ensure that the single voltage loop variables are initialized in each calculation cycle when switching to light load, the initialized variables are as follows: the integral calculation result of the inner current loop PI regulator in the dual-loop control (i.e., the dual-loop modulation base quantity) is assigned to the initial integral value of the single voltage loop PI regulator. Since the initial value of this integral quantity mainly determines the magnitude of the input voltage modulation, when switching instantaneously to a single voltage loop, the modulation quantity will not change abruptly, the output voltage will not change abruptly, and the switching of the entire system will be very smooth.

[0047] Optionally, step S1 includes: The main circuit input voltage signal is acquired in real time, and the main circuit input voltage signal is processed by differential operational amplifier to obtain the input voltage signal. The main circuit output voltage signal is acquired in real time, and the main circuit output voltage signal is processed by differential operational amplifier to obtain the output voltage signal. The main circuit output current signal is acquired in real time, and the main circuit output current signal is processed by differential operational amplifier to obtain the output current signal.

[0048] In this implementation, a signal processing module is set between the main circuit module and the digital control mode switching system. This module includes an input voltage sampling circuit, an inductor current sampling circuit, an output voltage sampling circuit, and a drive circuit. The input voltage sampling circuit is connected to the three-phase input terminals; the inductor current sampling circuit is electrically connected to one end of the series-connected output inductor Ln and sampling resistor Ro; and the output voltage sampling circuit is connected to both ends of the output capacitor Co. These three types of sampling signals are sent to the digital control mode switching system to provide feedback for the subsequent generation of PWM switching control signals in the main circuit. The drive circuit receives the switching control signals from the SVPWM modulation module and feeds them back to the switching transistor module of the main circuit module. This allows the PWM switching control signals generated by the control module to be sent through the drive circuit to the main circuit to control the switching devices (such as the six power switching transistors in the switching transistor module) for on / off operation.

[0049] Specifically, the output voltage across the output capacitor of the output voltage sampling circuit is scaled proportionally to a voltage that the DSP can process by a differential operational amplifier circuit to obtain the output voltage signal; the output inductor current signal can be obtained by a sampling resistor connected in series with the inductor, or by sampling the current through a current transformer. The current signal is then processed by a differential operational amplifier circuit to generate a signal that the DSP can process, thus obtaining the output current signal; the input voltage Va, Vb, and Vc information of the input voltage sampling circuit are processed by the DSP to generate the input voltage signal.

[0050] Example 2: This embodiment provides a dual-channel computing architecture for a digital control mode switching system, such as... Figure 4 As shown, it includes a first processing channel and a second processing channel, wherein: The first processing channel is a dual-ring processing channel; The second operation channel is a single-voltage loop operation channel; The first operation channel has a voltage outer loop, and the second operation channel is a single voltage loop. The input of the voltage loop in both operation channels is the output voltage signal Vo (including the output voltage signal, the current output voltage signal, and the real-time output voltage signal, etc.). A preset voltage reference value Vo_ref is stored in the loop. The difference between the two is used to obtain the voltage error signal V_error (including the voltage error signal, the current voltage error signal, and the real-time voltage error signal, etc.). The first operational channel also includes a current inner loop. The voltage outer loop PI regulator obtains the current inner loop reference value Iref based on V_error. The current inner loop PI regulator then uses this current inner loop reference value Iref and the currently fed-back output current signal as its basis. (Including the output current signal, real-time output current signal, and current output current signal, etc.) are modulated to obtain the dual-loop modulation quantity m2 (including the dual-loop modulation basic quantity and the instantaneous dual-loop modulation basic quantity). When the load is unloaded or lightly loaded, the sampled value of the output inductor current will be relatively small. The current sampled value is averaged and filtered. When the sampled inductor current value (which includes the output current signal, the real-time output current signal, and the current output current signal) is less than a certain specific value, it enters the second operation channel single voltage loop operation: after subtraction, the obtained V_error is sent to the single voltage loop PI regulator stage for calculation. The result of the calculation directly obtains the single loop modulation base quantity m1. When the sampled inductor current value is greater than a certain specific value, it enters the first operation channel dual loop operation. After obtaining the modulation amount m1 or m2, both operation channels multiply and normalize it with the instantaneous value V_abc of the AC grid voltage (including the input voltage signal, real-time input voltage signal, and current input voltage signal, etc.) to obtain the modulation wave signal, which is then input to the SVPWM modulation module to obtain the switching control signal. The single voltage loop is inactive, but the integral m1 needs to be assigned to the inner current loop in each operation cycle; similarly, the integral m2 of the inner current loop also needs to be assigned to the single voltage loop in each operation cycle.

[0051] Example 3: This embodiment provides a digital control mode switching system for implementing the aforementioned digital control mode switching method, including: The signal acquisition module is used to acquire the input voltage signal, output voltage signal, and output current signal of the main circuit module in real time. The digital control module is used to trigger entry into the single-voltage loop operation channel when the output current signal determines that a preset light no-load judgment condition is met. Within each operation cycle, it performs single-voltage loop proportional-integral operation based on the output voltage signal, a preset voltage reference value, and a pre-acquired initial voltage integral value to obtain a single-loop modulation base quantity; it obtains a switching control signal based on the single-loop modulation base quantity, the output voltage signal, and the input voltage signal to regulate the output voltage of the main circuit module based on the switching control signal; and it performs a dual-loop synchronous assignment operation on the dual-loop operation channel in parallel: assigning an initial value for the inner loop integral based on the single-loop modulation base quantity, assigning an initial value for the inner loop current reference based on the output current signal, and assigning an initial value for the outer loop integral based on the output current signal, so that when switching to the dual-loop operation channel is triggered, the switching control signal is output based on the initial value for the inner loop integral, the initial value for the inner loop current reference, and the initial value for the outer loop integral.

[0052] Optionally, the signal acquisition module includes an input voltage acquisition submodule, an output voltage acquisition submodule, and an output current acquisition submodule, wherein: The input voltage acquisition submodule is used to acquire the main circuit input voltage signal in real time, and to perform differential operational amplifier processing on the main circuit input voltage signal to acquire the input voltage signal. The output voltage acquisition submodule is used to acquire the main circuit output voltage signal in real time, and to perform differential operational amplifier processing on the main circuit output voltage signal to acquire the output voltage signal. The output current acquisition submodule is used to acquire the main circuit output current signal in real time, and to perform differential operational amplifier processing on the main circuit output current signal to obtain the output current signal.

[0053] Optionally, the digital control module is further configured to: acquire real-time input voltage signal, real-time output voltage signal, and real-time output current signal from the signal acquisition module; trigger switching to the dual-loop operation channel when a preset overload judgment condition is met based on the real-time output current signal; and execute instantaneous dual-loop operation actions at the instant the dual-loop operation channel is triggered: acquire an instantaneous error signal based on the inner loop current reference value and the real-time output current signal; perform proportional-integral operation of the current inner loop based on the instantaneous error signal and the initial value of the inner loop integral to acquire the instantaneous dual-loop modulation base quantity; and acquire a switching control signal based on the instantaneous dual-loop modulation base quantity, the real-time input voltage signal, and the real-time output voltage signal, so as to regulate the output voltage of the main circuit module based on the switching control signal.

[0054] Based on the above embodiments, this embodiment also provides a three-phase step-down PFC digital control device, such as... Figure 5As shown, it includes a main circuit module, a signal processing module, and a digital control section. The digital control section includes a sector determination unit and a dual-channel operation architecture.

[0055] It is understood that the above-described device embodiments correspond to the method embodiments of the present invention, and can implement the digital control mode switching method provided by any of the above-described method embodiments of the present invention.

[0056] It should be noted that the device embodiments described above are merely illustrative, and some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Furthermore, in the accompanying drawings of the device embodiments provided by this invention, the connection relationships between modules indicate that they have communication connections, which can specifically be implemented as one or more communication buses or signal lines. Those skilled in the art can understand and implement this without any creative effort.

[0057] Based on the above embodiments of the digital control mode switching method, another embodiment of the present invention provides a terminal device, which includes a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor. When the processor executes the computer program, it implements the digital control mode switching method of any embodiment of the present invention.

[0058] For example, in this embodiment, the computer program can be divided into one or more modules, which are stored in the memory and executed by the processor to complete the present invention. The one or more modules may be a series of computer program instruction segments capable of performing a specific function, which describe the execution process of the computer program in the terminal device.

[0059] The terminal device may be a desktop computer, laptop, handheld computer, or cloud server, etc. The terminal device may include, but is not limited to, a processor and a memory.

[0060] The processor can be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor can be a microprocessor or any conventional processor. The processor is the control center of the terminal device, connecting all parts of the terminal device via various interfaces and lines.

[0061] Based on the above-described method embodiments, another embodiment of the present invention provides a computer-readable storage medium including a stored computer program, wherein, when the computer program is executed, it controls the device where the computer-readable storage medium is located to execute the digital control mode switching method described in any of the above-described method embodiments of the present invention.

[0062] The modules / units integrated in the device / terminal equipment, if implemented as software functional units and sold or used as independent products, can be stored in a computer-readable storage medium. Based on this understanding, all or part of the processes in the above embodiments of the present invention can also be implemented by a computer program instructing related hardware. The computer program can be stored in a computer-readable storage medium, and when executed by a processor, it can implement the steps of the various method embodiments described above. The computer program includes computer program code, which can be in the form of source code, object code, executable files, or certain intermediate forms. The computer-readable medium can include: any entity or device capable of carrying the computer program code, a recording medium, a USB flash drive, a portable hard drive, a magnetic disk, an optical disk, a computer memory, a read-only memory (ROM), a random access memory (RAM), an electrical carrier signal, a telecommunication signal, and a software distribution medium, etc.

[0063] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A digital control mode switching method, characterized in that, An application in a digital control mode switching system, wherein the digital control mode switching system is electrically connected to the main circuit module, comprising: Real-time acquisition of the input voltage signal, output voltage signal, and output current signal of the main circuit module; When the output current signal is determined to meet the preset light no-load determination condition, it triggers entry into the single voltage loop operation channel. Within each operation cycle: Based on the output voltage signal, the preset voltage reference value, and the pre-acquired initial voltage integral value, a single voltage loop proportional-integral operation is performed to obtain the single-loop modulation base quantity; Based on the single-loop modulation base quantity, output voltage signal and input voltage signal, a switching control signal is obtained, and the output voltage of the main circuit module is regulated based on the switching control signal; Parallel synchronous assignment of values ​​is performed on the dual-loop operation channel: the initial value of the inner loop integral is assigned based on the single-loop modulation base quantity, the reference value of the inner loop current is assigned based on the output current signal, and the initial value of the outer loop integral is assigned based on the output current signal, so that when the switch to the dual-loop operation channel is triggered, the switching control signal is output based on the initial value of the inner loop integral, the reference value of the inner loop current, and the initial value of the outer loop integral.

2. The digital control mode switching method as described in claim 1, characterized in that, The step of performing single-loop proportional-integral calculations based on the output voltage signal, a preset voltage reference value, and a pre-acquired initial voltage integral value to obtain the single-loop modulation base quantity includes: A voltage error signal is obtained based on the output voltage signal and the preset voltage reference value; Based on the voltage error signal and the pre-acquired initial voltage integral value, a single-loop proportional-integral operation is performed to obtain the single-loop modulation base quantity.

3. The digital control mode switching method as described in claim 1, characterized in that, The step of obtaining a switching control signal based on the single-loop modulation base quantity, the output voltage signal, and the input voltage signal, and then regulating the output voltage of the main circuit module based on the switching control signal, includes: The current phase sector is obtained based on the input voltage signal and the preset space vector sector vector diagram of the main circuit module; Obtain the corresponding basic current vector based on the current phase sector; The corresponding control switch is obtained based on the corresponding basic current vector, and the preset period of the corresponding switch is obtained based on the corresponding control switch. The peak value of the input phase voltage is obtained based on the input voltage signal; Based on the input voltage signal, output voltage signal, single-loop modulation base quantity, input phase voltage peak value and corresponding preset period of the switch tube, the conduction switching time is calculated to obtain the switching tube's operating time. Based on the operating time of the switching transistor and the corresponding control switching transistor, a switching control signal is obtained to regulate the output voltage of the main circuit module.

4. The digital control mode switching method as described in claim 1, characterized in that, Also includes: Acquire the real-time input voltage signal, real-time output voltage signal, and real-time output current signal of the main circuit module; When the preset overload determination condition is met based on the real-time output current signal, the switch to the dual-ring operation channel is triggered. At the instant the dual-ring operation channel is switched, a momentary dual-ring operation is performed: The instantaneous error signal is obtained based on the inner loop current reference value and the real-time output current signal; Based on the instantaneous error signal and the initial value of the inner loop integral, the current inner loop proportional-integral operation is performed to obtain the instantaneous dual-loop modulation basic quantity; Based on the instantaneous dual-loop modulation base quantity, real-time input voltage signal, and real-time output voltage signal, a switching control signal is obtained to regulate the output voltage of the main circuit module.

5. The digital control mode switching method as described in claim 4, characterized in that, At the instant of triggering the switching of the dual-ring operation channel, after executing the instantaneous dual-ring operation action step, the method further includes, within each operation cycle: Real-time acquisition of current input voltage signal, current output voltage signal, and current output current signal; Based on the current output voltage signal, current output current signal, preset voltage reference value, instantaneous dual-loop modulation basic quantity and outer loop integration initial value, perform dual-loop integration calculation to obtain the dual-loop modulation basic quantity; Based on the dual-loop modulation base quantity, the current output voltage signal, and the current input voltage signal, a switching control signal is obtained to regulate the output voltage of the main circuit module based on the switching control signal. Parallel execution of single-loop synchronous assignment action: Assigning initial values ​​of voltage integral to a single voltage loop based on the dual-loop modulation base quantity; The initial value of the current inner loop integral is assigned to the voltage outer loop based on the aforementioned dual-loop modulation fundamental quantity.

6. The digital control mode switching method as described in claim 5, characterized in that, The step of performing dual-loop integration calculations based on the current output voltage signal, current output current signal, preset voltage reference value, instantaneous dual-loop modulation base quantity, and outer loop integration initial value to obtain the dual-loop modulation base quantity includes: The current voltage error signal is obtained based on the current output voltage signal and the preset voltage reference value; Based on the current voltage error signal and the initial value of the outer loop integral, voltage outer loop modulation calculation is performed to obtain the current inner loop reference value; The current error signal is obtained based on the current inner loop reference value and the current output current signal; Based on the current error signal and the initial value of the current inner loop integral, the proportional-integral operation of the current inner loop is performed to obtain the basic quantity of the dual-loop modulation.

7. The digital control mode switching method as described in claim 1, characterized in that, The real-time acquisition of the input voltage signal, output voltage signal, and output current signal of the main circuit module includes: The main circuit input voltage signal is acquired in real time, and the main circuit input voltage signal is processed by differential operational amplifier to obtain the input voltage signal. The main circuit output voltage signal is acquired in real time, and the main circuit output voltage signal is processed by differential operational amplifier to obtain the output voltage signal. The main circuit output current signal is acquired in real time, and the main circuit output current signal is processed by differential operational amplifier to obtain the output current signal.

8. A digital control mode switching system, characterized in that, A method for switching digital control modes as described in any one of claims 1 to 7, comprising: The signal acquisition module is used to acquire the input voltage signal, output voltage signal, and output current signal of the main circuit module in real time. The digital control module is used to trigger entry into the single-voltage loop operation channel when the output current signal determines that a preset light no-load judgment condition is met. Within each operation cycle, it performs single-voltage loop proportional-integral operation based on the output voltage signal, a preset voltage reference value, and a pre-acquired initial voltage integral value to obtain a single-loop modulation base quantity; it obtains a switching control signal based on the single-loop modulation base quantity, the output voltage signal, and the input voltage signal to regulate the output voltage of the main circuit module based on the switching control signal; and it performs a dual-loop synchronous assignment operation on the dual-loop operation channel in parallel: assigning an initial value for the inner loop integral based on the single-loop modulation base quantity, assigning an initial value for the inner loop current reference based on the output current signal, and assigning an initial value for the outer loop integral based on the output current signal, so that when switching to the dual-loop operation channel is triggered, the switching control signal is output based on the initial value for the inner loop integral, the initial value for the inner loop current reference, and the initial value for the outer loop integral.

9. A digital control mode switching system as described in claim 8, characterized in that, The signal acquisition module includes an input voltage acquisition submodule, an output voltage acquisition submodule, and an output current acquisition submodule, wherein: The input voltage acquisition submodule is used to acquire the main circuit input voltage signal in real time, and to perform differential operational amplifier processing on the main circuit input voltage signal to acquire the input voltage signal. The output voltage acquisition submodule is used to acquire the main circuit output voltage signal in real time, and to perform differential operational amplifier processing on the main circuit output voltage signal to acquire the output voltage signal. The output current acquisition submodule is used to acquire the main circuit output current signal in real time, and to perform differential operational amplifier processing on the main circuit output current signal to obtain the output current signal.

10. A digital control mode switching system as described in claim 8, characterized in that, The digital control module is further configured to: acquire real-time input voltage signal, real-time output voltage signal, and real-time output current signal from the signal acquisition module; trigger a switch to the dual-loop operation channel when a preset overload judgment condition is met based on the real-time output current signal; and execute instantaneous dual-loop operation actions at the instant the switch to the dual-loop operation channel is triggered: acquire an instantaneous error signal based on the inner loop current reference value and the real-time output current signal; perform proportional-integral operation of the current inner loop based on the instantaneous error signal and the initial value of the inner loop integral to acquire the instantaneous dual-loop modulation base quantity; and acquire a switching control signal based on the instantaneous dual-loop modulation base quantity, the real-time input voltage signal, and the real-time output voltage signal, so as to regulate the output voltage of the main circuit module based on the switching control signal.

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