Totem pole PFC circuit control system and control method

Abstract

The embodiment of the invention relates to the field of circuits, and provides a totem-pole PFC circuit control system and method, and the system comprises a totem-pole PFC circuit which comprises a zero-crossing switching state and a non-zero-crossing switching state; during the zero-crossing switching state of the first control module, a first duty ratio of a first control signal for driving a main switch tube is controlled to be increased from a first initial duty ratio to a first target duty ratio, and then a second duty ratio of a second control signal for driving a synchronous tube is controlled to be increased from a second initial duty ratio to a second target duty ratio; when the second control module is in a non-zero-crossing switching state, the voltage value of the output voltage of the totem pole PFC circuit is controlled to be within a preset range; and after the first duty ratio is increased to a first target duty ratio, the main switch tube is controlled by the second control module, and after the second duty ratio is increased to a second target duty ratio, the synchronous tube is controlled by the second control module. The current peak oscillation problem of the totem-pole PFC circuit in the zero-crossing switching state can be improved.

Description

Technical Field

[0001] The disclosed embodiments relate to the field of circuits, and in particular to a totem pole PFC circuit control system and control method. Background Art

[0002] As the demand for energy efficiency continues to increase, the application of Power Factor Correction (PFC) technology has become a mandatory requirement. Especially in the fields of switching power supplies, consumer electronics, industrial equipment, etc., relevant energy efficiency standards must be followed. Efficient PFC circuits can help equipment meet these standard requirements and reduce harmonic pollution to the power grid.

[0003] Although traditional PFC topologies (such as Boost PFC) have been widely used, their efficiency is limited in high-frequency operation, especially when the input AC voltage first passes through a full-bridge rectifier circuit to convert the AC voltage into a DC voltage. These rectifier diodes will produce large conduction losses and reverse recovery losses in high-power applications, especially in high-current and high-frequency applications, where the diode loss accounts for a large part of the total loss and becomes the main bottleneck limiting efficiency.

[0004] With the rise of third-generation semiconductor materials (such as GaN and SiC), the field of power electronics has entered a new stage of high frequency and high efficiency. Compared with traditional silicon-based devices, these new power devices have lower on-resistance and higher operating frequency, making it possible to design smaller and more efficient PFC circuits.

[0005] The totem pole PFC architecture is a topology that can fully utilize the characteristics of GaN and SiC power devices. Figure 1 It is its circuit topology. By operating at high frequency and reducing conduction losses, it greatly improves the efficiency of the power factor correction circuit while reducing complexity and cost. Therefore, the totem pole PFC circuit is considered to be the next generation of high-efficiency PFC solution because it can significantly improve efficiency, reduce losses, and simplify design.

[0006] However, the current totem pole PFC circuit will generate a current spike during zero-crossing switching, which will affect the output of the totem pole PFC circuit. Summary of the invention

[0007] The disclosed embodiments provide a totem pole PFC circuit control system and control method, which can at least improve the current spike oscillation problem of the totem pole PFC circuit in the zero-crossing switching state.

[0008] According to some embodiments of the present disclosure, on the one hand, the embodiments of the present disclosure provide a totem pole PFC circuit control system, including: a totem pole PFC circuit, the totem pole PFC circuit including a zero-crossing switching state and a non-zero-crossing switching state divided according to the phase of the input alternating current; a first control module, the first control module is electrically connected to the totem pole PFC circuit, and is used to control the first duty cycle of the first control signal driving the main switch tube to gradually increase from the first initial duty cycle to the first target duty cycle during the period when the totem pole PFC circuit is in the zero-crossing switching state, and after the first duty cycle increases to the first target duty cycle, control the first duty cycle of the second control signal driving the synchronous tube to gradually increase from the first initial duty cycle to the first target duty cycle. The second duty cycle gradually increases from the second initial duty cycle to the second target duty cycle, and during the zero-crossing switching state, at most one of the main switch tube and the synchronous tube is turned on at the same time; a second control module, the second control module is electrically connected to the totem pole PFC circuit, and is used to control the voltage value of the output voltage of the totem pole PFC circuit to be within a preset range when the totem pole PFC circuit is in the non-zero-crossing switching state; wherein, after the first duty cycle increases to the first target duty cycle, the main switch tube is controlled by the second control module, and after the second duty cycle increases to the second target duty cycle, the synchronous tube is controlled by the second control module.

[0009] In some embodiments, the second control module includes: a detection unit, the detection unit acquires the first duty cycle, generates and outputs a first current signal and a first voltage signal, the first current signal is a current value flowing through the PFC inductor, and the first voltage signal is an output voltage of the totem pole PFC circuit; a voltage modulation unit, electrically connected to the detection unit, configured to receive the first voltage signal and acquire an alternating current signal at an input end of the totem pole PFC circuit, and generate and output a current reference signal according to an output reference voltage of the totem pole PFC circuit; a current modulation unit, electrically connected to the detection unit and the voltage modulation unit, configured to receive the first current signal and the current reference signal, and generate and output the first control signal and the second control signal for controlling the main switch tube and the synchronous tube.

[0010] In some embodiments, the voltage modulation unit includes: a voltage loop compensator, which is electrically connected to the detection unit and is used to receive the first voltage signal and generate and output current value information corresponding to the current reference signal according to the output reference voltage of the totem pole PFC circuit; a phase compensator, which obtains the AC signal at the input end of the totem pole PFC circuit and generates and outputs phase information corresponding to the current reference signal; and an integrator, which is electrically connected to the voltage loop compensator and the phase compensator, obtains the current value information generated by the voltage loop compensator and the phase information generated by the phase compensator, and generates and outputs the current reference signal.

[0011] In some embodiments, the phase compensator includes: a SOGI phase-locked loop, which receives an AC signal at an input end of the totem pole PFC circuit; an absolute value compensation circuit, which receives an AC signal at an input end of the totem pole PFC circuit; and a mode selector, which is electrically connected to an output end of the SOGI phase-locked loop and an output end of the absolute value compensation circuit, and selects one of the SOGI phase-locked loop and the absolute value compensation circuit to be turned on with the integrator.

[0012] In some embodiments, the voltage modulation unit also includes: a fast start unit, the fast start unit is electrically connected to the voltage loop compensator, the fast start unit has first preset current value information, the fast start unit also obtains the current value information output by the voltage loop compensator, and superimposes the first preset current value information on the current value information output by the voltage loop compensator, and outputs the superimposed information as the current value information of the current reference signal to the integrator.

[0013] In some embodiments, the current modulation unit includes: a direction determiner, which is electrically connected to the detection unit and is used to receive the first current signal and determine the direction of the first current signal; a current loop compensator, which is electrically connected to the direction determiner and the voltage modulation unit, receives the first current signal and the current reference signal, and generates a second current signal according to the direction of the first current signal; a PWM generator, which is electrically connected to the current loop compensator, receives the second current signal, generates and outputs the first control signal and the second control signal.

[0014] In some embodiments, the current modulation unit also includes: a saturation limiter, which is electrically connected to the current loop compensator, and the input end of the saturation limiter receives the second current signal, and when the current value of the second current signal is less than the current value of the second preset current value information in the saturation limiter, the second current signal is controlled to be transmitted to the PWM generator; when the current value of the second current signal is greater than the current value of the second preset current value information in the saturation limiter, the second preset current value information is controlled to be transmitted as the second current signal to the PWM generator.

[0015] In some embodiments, the second control module further includes: a notch filter, which is connected between the detection unit and the voltage modulation unit to filter the first voltage signal.

[0016] In some embodiments, the first duty cycle increases from the first initial duty cycle at a fixed step size pulse cycle by pulse cycle, or the step size of the first duty cycle increasing per pulse cycle forms a geometric progression, and / or the second duty cycle increases from the second initial duty cycle at a fixed step size pulse cycle by pulse cycle, or the step size of the second duty cycle increasing per pulse cycle forms a geometric progression.

[0017] According to some embodiments of the present disclosure, another aspect of the present disclosure is to provide a totem pole PFC circuit, wherein the totem pole PFC circuit includes a zero-crossing switching state and a non-zero-crossing switching state divided according to the phase of the input alternating current; during the period when the totem pole PFC circuit is in the zero-crossing switching state, the first control module is controlled to drive the first duty cycle of the first control signal of the main switch tube to gradually increase from the first initial duty cycle to the first target duty cycle, and after the first duty cycle increases to the first target duty cycle, the second duty cycle of the second control signal driving the synchronous tube is controlled to gradually increase from the second initial duty cycle to the second target duty cycle, and during the period when the second duty cycle increases, the first duty cycle gradually decreases; when the totem pole PFC circuit is in the non-zero-crossing switching state, the second control module is controlled to drive the voltage value of the output voltage of the totem pole PFC circuit to be within a preset range; wherein, after the first duty cycle increases to the first target duty cycle, the main switch tube is controlled by the second control module, and after the second duty cycle increases to the second target duty cycle, the synchronous tube is controlled by the second control module.

[0018] In some embodiments, during the period when the first duty cycle increases, the synchronous tube is controlled to remain turned off.

[0019] In some embodiments, the time required for the first duty cycle to increase to a first target duty cycle is a first time, and the interval time between controlling the start-up of the main switch tube and the synchronization tube is greater than the first time.

[0020] In some embodiments, during the period when the voltage of the alternating current at the input end of the totem pole PFC circuit switches from the negative half-cycle to the positive half-cycle, before the second duty cycle increases to the second target duty cycle, the first power frequency tube directly electrically connected to the synchronization tube is controlled to remain turned on, and the second power frequency tube directly electrically connected to the main switch tube is controlled to remain turned off; after the second duty cycle increases to the second target duty cycle, the first power frequency tube is controlled to be turned off, and the second power frequency tube is controlled to be turned on after a preset time interval.

[0021] In some embodiments, the totem pole PFC circuit includes: a first high frequency tube and a second high frequency tube, the first duty cycle is gradually increased from the first initial duty cycle to the first target duty cycle, and after the first duty cycle is increased to the first target duty cycle, the second duty cycle is controlled to gradually increase from the second initial duty cycle to the second target duty cycle, including: if the zero-crossing switching state is that the voltage of the alternating current at the input end of the totem pole PFC circuit switches from a negative half cycle to a positive half cycle, the second high frequency tube is used as the main switch tube, the first duty cycle of the second high frequency tube is gradually increased from the first initial duty cycle to the first target duty cycle, and in the zero-crossing switching state of the second high frequency tube After the first duty cycle increases to the first target duty cycle, the second duty cycle of the first high-frequency tube is controlled to gradually increase from the second initial duty cycle to the second target duty cycle; if the zero-crossing switching state is that the voltage of the alternating current at the input end of the totem pole PFC circuit switches from a positive half-cycle to a negative half-cycle, the first high-frequency tube serves as the main switch tube, the first duty cycle of the first high-frequency tube is gradually increased from the first initial duty cycle to the first target duty cycle, and after the first duty cycle of the first high-frequency tube is increased to the first target duty cycle, the second duty cycle of the second high-frequency tube is controlled to gradually increase from the second initial duty cycle to the second target duty cycle.

[0022] In some embodiments, while the first duty cycle gradually increases from the first initial duty cycle to the first target duty cycle, the first duty cycle is increased pulse cycle by pulse cycle with a first fixed step size, and / or, while the second duty cycle gradually increases from the second initial duty cycle to the second target duty cycle, the second duty cycle is increased pulse cycle by pulse cycle with a second fixed step size.

[0023] In some embodiments, the first fixed step size is equal to the second fixed step size.

[0024] The technical solution provided by the embodiment of the present disclosure has at least the following advantages: when the totem pole PFC circuit is in the zero-crossing switching state, the PFC inductor current rises and falls sharply, which will generate a large number of peak oscillations, resulting in a decrease in power factor and an increase in output harmonics. When the totem pole PFC circuit is in the zero-crossing switching state, the pulse width of the main switch tube is controlled to gradually increase from a very small value, so that the synchronous tube completes reverse recovery, thereby eliminating the current spike on the PFC inductor. After the main switch tube completes the soft start process, the synchronous tube is controlled to complete the soft start process to eliminate the current spike caused by the load voltage. Moreover, the embodiment of the present disclosure uses the first control module to control the soft start process of the main switch tube and the synchronous tube during the period when the totem pole PFC circuit is in the zero-crossing switching state, thereby further improving the stability of the output voltage of the totem pole PFC circuit and further improving the current spike problem of the totem pole PFC circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] One or more embodiments are exemplarily illustrated by pictures in the corresponding drawings, and these exemplified descriptions do not constitute a limitation on the embodiments. Unless otherwise specified, the pictures in the drawings do not constitute a scale limitation. In order to more clearly illustrate the embodiments of the present disclosure or the technical solutions in the traditional technology, the drawings required for use in the embodiments are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present disclosure. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0026] Figure 1 A module diagram of a totem pole PFC circuit control system provided by an embodiment of the present disclosure;

[0027] Figure 2 A circuit diagram of a totem pole PFC circuit provided in one embodiment of the present disclosure;

[0028] Figure 3 A circuit diagram of a totem pole PFC circuit connected to a second control module provided by an embodiment of the present disclosure;

[0029] Figure 4 A circuit diagram of a second control module provided in one embodiment of the present disclosure;

[0030] Figure 5 A waveform diagram of a PFC inductor current and input AC power provided by an embodiment of the present disclosure;

[0031] Figure 6 A timing diagram of each part corresponding to a zero-crossing switching state in which the voltage of the alternating current at the input end of a totem pole PFC circuit switches from a negative half-cycle to a positive half-cycle provided by an embodiment of the present disclosure;

[0032] Figure 7 A flowchart of a totem pole PFC circuit control method provided by an embodiment of the present disclosure. DETAILED DESCRIPTION

[0033] As known from the background art, the current totem pole PFC circuit will generate a current spike during the zero-crossing switching state, which will affect the output of the totem pole PFC circuit.

[0034] The disclosed embodiment of the present invention controls the pulse width of the main switch tube to gradually increase from a very small value when the totem pole PFC circuit is in a zero-crossing switching state, so that the synchronous tube completes reverse recovery, thereby eliminating the current spike on the PFC inductor. After the main switch tube completes the soft-start process, the synchronous tube is controlled to complete the soft-start process to eliminate the current spike caused by the load voltage. Moreover, the disclosed embodiment of the present invention uses the first control module to control the soft-start process of the main switch tube and the synchronous tube during the period when the totem pole PFC circuit is in the zero-crossing switching state, thereby further improving the stability of the output voltage of the totem pole PFC circuit and further improving the current spike problem of the totem pole PFC circuit.

[0035] Terms such as first or second can be used to describe various components, but these components are not limited by the above terms. The above terms are used to distinguish one component from another component, for example, without departing from the scope of the concept according to the present disclosure, a first component can be referred to as a second component, and similarly, a second component can be referred to as a first component.

[0036] In addition, "connected / coupled" means that one component is directly electrically coupled to another component or is indirectly electrically coupled through another component. The singular form may include the plural form unless explicitly stated in the sentence. In addition, "include / comprise" or "includes / comprises" used in this specification indicates that one or more components, steps, operations, and elements exist or have been added. The specific structural or functional descriptions of the examples of the implementation of the concepts disclosed in this specification are only illustrated to describe the examples of the implementation of the concepts, and the examples of the implementation of the concepts can be implemented in various forms, but these descriptions are not limited to the examples of the implementation described in this specification.

[0037] According to the concept, various modifications and changes can be applied to the examples of the embodiments, so that the examples of the embodiments will be illustrated in the drawings and described in the specification. However, the examples of the embodiments according to the concept are not limited to the specific embodiments, but include all changes, equivalents or replacements included in the spirit and technical scope of the present disclosure.

[0038] It should be understood that when an element is described as being "coupled" or "connected" to another element, the element may be directly coupled or directly connected to the other element, or may be coupled or connected to the other element through a third element. Conversely, it should be understood that when an element is referred to as being "directly coupled to" or "directly coupled to" another element, no other element is placed between them. Other expressions describing the relationship between components (i.e., "between" and "directly between" or "adjacent to" and "directly adjacent to") need to be interpreted in the same manner.

[0039] The terms used in this specification are only used to describe specific examples of the embodiments and are not intended to limit the present disclosure. If there is no clear opposite meaning in the context, the singular form may include the plural form. In this specification, it should be understood that the term "including" or "having" indicates the presence of the features, quantities, steps, operations, components, parts or combinations thereof described in the specification, but the possibility of the presence or addition of one or more other features, quantities, steps, operations, components, parts or combinations thereof cannot be precluded.

[0040] If there is no contrary definition, all terms (including technical terms or scientific terms) used herein have the same meaning as those generally understood by ordinary technicians in the field. If the terms defined in the commonly used dictionary are not clearly defined in this specification, they should be interpreted as having the same meaning as in the context of the relevant technology, and not interpreted as ideal or overly formal meanings.

[0041] Descriptions of well-known components and processing techniques may be omitted so as not to unnecessarily obscure the embodiments of the disclosure.

[0042] Throughout the specification, the same reference numerals refer to the same elements. Thus, even if a reference numeral is not mentioned or described with reference to one figure, it may be mentioned or described with reference to another figure. Furthermore, even if a reference numeral is not shown in one figure, it may be mentioned or described with reference to another figure.

[0043] In addition, the logic level of the signal may be different or opposite to the described logic level. For example, a signal described as having a logic "high" level may alternatively have a logic "low" level, and a signal described as having a logic "low" level may alternatively have a logic "high" level.

[0044] The following will describe the various embodiments of the present disclosure in detail with reference to the accompanying drawings. However, it will be appreciated by those skilled in the art that in the various embodiments of the present disclosure, many technical details are provided in order to enable the reader to better understand the present disclosure. However, even without these technical details and various changes and modifications based on the following embodiments, the technical solutions claimed in the present disclosure can be implemented.

[0045] refer to Figures 1 to 5 , Figure 1 A module diagram of a totem pole PFC circuit control system provided by an embodiment of the present disclosure; Figure 2 A circuit diagram of a totem pole PFC circuit provided in an embodiment of the present disclosure, Figure 3 A circuit diagram of a totem pole PFC circuit connected to a second control module provided by an embodiment of the present disclosure; Figure 4 A circuit diagram of a second control module provided in one embodiment of the present disclosure; Figure 5 A waveform diagram of a PFC inductor current and input alternating current provided by an embodiment of the present disclosure.

[0046] In some embodiments, a totem pole PFC circuit control system may include: a totem pole PFC circuit 100 , wherein the totem pole PFC circuit 100 includes a zero-crossing switching state and a non-zero-crossing switching state divided according to a phase of an input alternating current Vac.

[0047] The totem pole PFC circuit control system may further include: a first control module 101, the first control module 101 is electrically connected to the totem pole PFC circuit 100, and is used to control the first duty cycle of the first control signal driving the main switch tube to gradually increase from the first initial duty cycle to the first target duty cycle during the period when the totem pole PFC circuit 100 is in the zero-crossing switching state, and after the first duty cycle increases to the first target duty cycle, control the second duty cycle of the second control signal driving the synchronous tube to gradually increase from the second initial duty cycle to the second target duty cycle. During the zero-crossing switching state, at most one of the main switch tube and the synchronous tube is turned on at the same time.

[0048] The totem pole PFC circuit control system may further include: a second control module 102, the second control module 102 is electrically connected to the totem pole PFC circuit 100, and is used to control the voltage value of the output voltage of the totem pole PFC circuit 100 to be within a preset range when the totem pole PFC circuit 101 is in a non-zero-crossing switching state.

[0049] refer to Figure 2 For the totem pole PFC circuit 100, the totem pole PFC circuit 100 may include: input AC power Vac, a PFC inductor L1, a first high-frequency tube S1, a second high-frequency tube S2, a first power frequency tube S3, a second power frequency tube S4, a PFC capacitor C1 and a resistor R1.

[0050] The input AC power Vac is a sinusoidal waveform, and can be divided into a zero-crossing switching state and a non-zero-crossing switching state according to the phase of the input AC power Vac. The non-zero-crossing switching state may include a positive half-cycle and a negative half-cycle, and the zero-crossing switching state is a state where the positive half-cycle switches to the negative half-cycle, or a state where the negative half-cycle switches to the positive half-axis.

[0051] When the input AC power Vac is in the positive half cycle, the second high-frequency tube S2 serves as the main switch tube, the first high-frequency tube S1 serves as the synchronous tube, the second power-frequency tube S4 remains on, and the first power-frequency tube S3 remains off. When the second high-frequency tube S2 is turned on and the first high-frequency tube S1 is turned off, the current in the loop flows from the positive electrode of the input AC power Vac through the second high-frequency tube S2 and the second power-frequency tube S4 and then returns to the negative electrode of the input AC power Vac. During this period, the PFC capacitor C1 boosts the power supply to the resistor R1 and maintains the output voltage Vout. When the first high-frequency tube S1 is turned on and the second high-frequency tube S2 is turned off, the current in the loop flows from the positive electrode of the input AC power Vac through the resistor R1 and the second power-frequency tube S4 and then returns to the negative electrode of the input AC power Vac. During this period, the input AC power Vac and the PFC inductor L1 boost the power supply to the resistor R1 and maintain the output voltage Vout.

[0052] When the input AC power Vac is in the negative half cycle, the first high-frequency tube S1 serves as the main switch tube, the second high-frequency tube S2 serves as the synchronous tube, the first power-frequency tube S3 remains on, and the second power-frequency tube S4 remains off. When the first high-frequency tube S1 is turned on and the second high-frequency tube S2 is turned off, the current in the loop flows from the positive electrode of the input AC power Vac through the first power-frequency tube S3 and the first high-frequency tube S1 and then returns to the negative electrode of the input AC power Vac. During this period, the PFC capacitor C1 boosts the power supply to the resistor R1 and maintains the output voltage. When the first high-frequency tube S1 is turned off and the second high-frequency tube S2 is turned on, the current in the loop flows from the positive electrode of the input AC power Vac through the first power-frequency tube S3, the resistor R1 and the second high-frequency tube S2 and then returns to the negative electrode of the input AC power Vac. During this period, the input AC power Vac and the PFC inductor L1 boost the power supply to the resistor R1 and maintain the output voltage.

[0053] It can be understood that when the input AC power Vac switches from the negative half cycle to the positive half cycle or from the positive half cycle to the negative half cycle, a current spike will be generated. Taking the case where the input AC power Vac switches from the negative half cycle to the positive half cycle as an example, the duty cycle of the control signal of the first high-frequency tube S1 changes from almost 100% to zero, and the duty cycle of the control signal of the second high-frequency tube S2 suddenly changes from zero to 100%. Due to the reverse recovery of the first power-frequency tube S3 and the second power-frequency tube S4, the voltage of the second power-frequency tube S4 is still close to the output voltage, and when the second high-frequency tube S2 is turned on, the voltage is applied to P FC inductor, so a positive current spike will be generated. If the second power-frequency tube S4 is turned on between the second high-frequency tube S2 and the first power-frequency tube S3 has not recovered in time, there will be a risk of short circuit. If the second power-frequency tube S4 is turned on too late, a negative current spike will also be generated. When the first high-frequency tube S1 is turned on and the second high-frequency tube S2 is turned off, the high bus voltage will generate a reverse PFC inductor current. This reverse PFC inductor current first turns off the second power-frequency tube S4 and then charges the second power-frequency tube S4. Subsequently, if the second high-frequency tube S2 is turned on, this high voltage is applied to the PFC inductor, generating a high rising current.

[0054] On the other hand, since the voltage after zero-crossing switching is low and insufficient to increase the PFC inductor current, when the first high-frequency tube S1 is turned on, even if the duty cycle of the control signal of the first high-frequency tube S1 is not high, the voltage applied to the PFC inductor by the resistor R1 is also high, thereby generating a negative current spike of the PFC inductor.

[0055] From the above content, it can be seen that when the totem pole PFC circuit is in the zero-crossing switching state, the PFC inductor current rises and falls sharply, thereby generating a large number of peak oscillations, which in turn causes a decrease in the power factor and an increase in output harmonics.

[0056] Based on this, the embodiment of the present disclosure controls the pulse width of the main switch tube to gradually increase from a very small value when the totem pole PFC circuit 100 is in the zero-crossing switching state, so that the synchronous tube completes reverse recovery, thereby eliminating the current spike on the PFC inductor L1. After the main switch tube completes the soft start process, the synchronous tube is controlled to complete the soft start process to eliminate the current spike caused by the load voltage. Moreover, the embodiment of the present disclosure uses the first control module 101 to control the soft start process of the main switch tube and the synchronous tube during the period when the totem pole PFC circuit 100 is in the zero-crossing switching state, thereby further improving the stability of the output voltage Vout of the totem pole PFC circuit 100 and further improving the current spike problem of the totem pole PFC circuit 100.

[0057] For the first control module 101, the first control module 101 can be a control signal preset in the chip. When it is detected that the input AC power Vac is in a zero-crossing switching state, the first control signal for controlling the main switch tube is output, and after the first initial duty cycle of the first control signal of the main switch tube increases to the first target duty cycle, the second control signal for controlling the synchronous tube is output.

[0058] It is understandable that, according to the above content, it can be determined that one of the first high-frequency tube S1 or the second high-frequency tube S2 is used as the main switch tube, and the other is used as the synchronous tube.

[0059] As for the second control module 102, the second control module 102 is used to generate a control signal for controlling the main switch tube and the synchronous tube according to the output reference voltage Vref of the totem pole PFC circuit 100 when the totem pole PFC circuit 100 is in a non-zero-crossing switching state, so that the voltage value of the output voltage Vout of the totem pole PFC circuit 100 is within a preset range.

[0060] It should be noted that, making the voltage value of the output voltage Vout of the totem pole PFC circuit 100 within the preset range may mean that the voltage value of the output voltage Vout itself is within the expected range, or may mean that the difference between the voltage value of the output voltage Vout and the voltage value of the output reference voltage Vref is within the preset range, where the output reference voltage Vref refers to the theoretical output voltage Vout of the circuit.

[0061] refer to Figure 3 In some embodiments, the second control module 102 includes: a detection unit 112, the detection unit 112 obtains a first duty cycle, generates and outputs a first current signal and a first voltage signal, the first current signal is a current value flowing through the PFC inductor L1, and the first voltage signal is an output voltage Vout of the totem pole PFC circuit 100; a voltage modulation unit 122, electrically connected to the detection unit 112, for receiving the first voltage signal and obtaining an AC signal at an input end of the totem pole PFC circuit 100, and generating and outputting a current reference signal according to an output reference voltage Vref of the totem pole PFC circuit 100; a current modulation unit 132, electrically connected to the detection unit 112 and the voltage modulation unit 122, for receiving the first current signal and the current reference signal, and generating and outputting a first control signal and a second control signal for controlling the main switch tube and the synchronous tube.

[0062] The first duty cycle is acquired in real time by the detection unit 112, and a first current signal and a first voltage signal are generated. The first current signal and the first voltage signal are used as adjustment basis of the voltage modulation unit 122 and the current modulation unit 132. The voltage modulation unit 122 is used to compensate the output voltage Vout of the totem pole PFC circuit 100 according to the current output voltage Vout of the totem pole PFC circuit 100 and the current output reference voltage Vref of the totem pole PFC circuit 100, and generate a current reference signal. The current reference signal is used as a reference of the current modulation unit 132, so that the current modulation unit 132 compensates the first current signal, and generates a first control signal and a second control signal for controlling the main switch tube and the synchronous tube according to the compensated current signal. The first duty cycle is acquired by looping, and the first control signal and the second control signal are continuously adjusted according to the reference output reference voltage Vref and the current reference signal, so as to maintain the output voltage Vout close to the output reference voltage Vref, and the power factor of the totem pole PFC circuit 100 is corrected by the cooperation of the voltage modulation unit 122 and the current modulation unit 132.

[0063] refer to Figure 4 In some embodiments, the voltage modulation unit 122 may include: a voltage loop compensator 1220, the voltage loop compensator 1220 is electrically connected to the detection unit 112, and is used to receive the first voltage signal, and generate and output current value information corresponding to the current reference signal according to the output reference voltage Vref of the totem pole PFC circuit 100; a phase compensator 1221, the phase compensator 1221 obtains the AC power signal at the input end of the totem pole PFC circuit 100, generates and outputs phase information corresponding to the current reference signal; an integrator 1222, the integrator 1222 is electrically connected to the voltage loop compensator 1220 and the phase compensator 1221, obtains the current value information generated by the voltage loop compensator 1220 and the phase information generated by the phase compensator 1221, and generates and outputs the current reference signal.

[0064] The voltage loop compensator 1220 is a part used to compensate for the voltage value of the output voltage Vout, thereby generating current value information corresponding to the current reference signal, and the phase compensator 1221 is used to adjust the phase of the current reference signal output by the voltage modulation unit 122 to be consistent with the input voltage, and integrate the current value information corresponding to the current reference signal generated by the voltage loop compensator 1220 and the phase information corresponding to the current reference signal generated by the phase compensator 1221 through the integrator 1222, thereby generating a current reference signal with phase information, so as to facilitate the current modulation unit 132 to compensate the first current signal according to the current reference signal, and facilitate the current modulation unit 132 to correct the power factor of the totem pole PFC circuit 100.

[0065] In some embodiments, the voltage loop compensator 1220 can compensate the voltage value of the output voltage Vout by using a proportional integral link (PI), and the proportional parameter and the integral parameter can be designed according to the transfer function. By using a proportional integral link (PI) to compensate the voltage value of the output voltage Vout, the stability of the output of the voltage loop compensator 1220 can be improved. Moreover, for the voltage loop compensator 1220, the voltage loop compensator 1220 compensates the voltage value, and it is more suitable to use a proportional integral link (PI) for a DC signal.

[0066] The integrator 1222 may be a multiplier, which can perform the multiplication of two unrelated analog signals, thereby generating a current reference signal having both current value information and phase information.

[0067] In some embodiments, the phase compensator 1221 includes: a SOGI phase-locked loop 1223, which receives an AC signal at an input end of the totem pole PFC circuit 100; an absolute value compensation circuit 1224, which receives an AC signal at an input end of the totem pole PFC circuit 100; and a mode selector 1225, which is electrically connected to an output end of the SOGI phase-locked loop 1223 and an output end of the absolute value compensation circuit 1224, and selects one of the SOGI phase-locked loop 1223 and the absolute value compensation circuit 1224 to be connected to the integrator 1222.

[0068] By utilizing the mode selector 1225 to select either the SOGI phase-locked loop 1223 or the absolute value compensation circuit 1224 to be turned on with the integrator 1222, the phase information of the output current reference signal is realized, so that the current reference signal received in the current modulation unit 132 is kept consistent in phase with the input voltage, thereby achieving power factor correction.

[0069] In some embodiments, in application scenarios where the grid frequency fluctuation is not large, the use of the SOGI phase-locked loop 1223 can track the phase information more accurately, thereby achieving a better power factor correction effect. The mode selector 1225 selects either the SOGI phase-locked loop 1223 or the absolute value compensation circuit 1224 to be turned on with the integrator 1222 according to different application scenarios, thereby improving the universality of the totem pole PFC circuit 100 control system.

[0070] In some embodiments, the absolute value compensation circuit 1224 may first obtain the absolute value of the AC signal, and then obtain the phase of the AC signal by means of RMS (Root Mean Square) phase.

[0071] In some other embodiments, the phase compensator 1221 may also include only one of the SOGI phase-locked loop 1223 and the absolute value compensation circuit 1224 .

[0072] In some embodiments, the voltage modulation unit 122 also includes: a fast start unit 1226, the fast start unit 1226 is electrically connected to the voltage loop compensator 1220, the fast start unit 1226 has a first preset current value information, the fast start unit 1226 also obtains the current value information output by the voltage loop compensator 1220, and superimposes the first preset current value information on the current value information output by the voltage loop compensator 1220, and outputs the superimposed information as the current value information of the current reference signal to the integrator 1222.

[0073] For example, the first preset current value information of the fast start unit 1226 is 1A. After the voltage loop compensator 1220 outputs the current value information, the first preset current value information of the fast start unit 1226 will be superimposed on the current value information output by the voltage loop compensator 1220. For example, the current value information output by the voltage loop compensator 1220 is 1A, and the current value information transmitted to the integrator 1222 via the fast start unit 1226 is 2A. The fast start unit 1226 can reduce the calculation pressure of the voltage modulation unit 122, thereby avoiding continuous integration through the voltage loop compensator 1220 and occupying a large amount of computing power, thereby improving the response rate of the entire totem pole PFC circuit 100 control system and improving the performance of the totem pole PFC circuit 100 control system.

[0074] In some embodiments, the current modulation unit 132 includes: a direction determiner 1320, which is electrically connected to the detection unit 112, and is used to receive a first current signal and determine the direction of the first current signal; a current loop compensator 1321, which is electrically connected to the direction determiner 1320 and the voltage modulation unit 122, receives the first current signal and the current reference signal, and generates a second current signal according to the direction of the first current signal; a PWM generator 1322, which is electrically connected to the current loop compensator 1321, receives the second current signal to generate and output a first control signal and a second control signal.

[0075] The direction of the first current signal is determined by direction judgment, so that the current loop compensator 1321 can compensate the first current signal. The first current signal is compensated by the current reference signal, so that the first control signal and the second control signal output by the PWM generator 1322 can control the waveform output by the totem pole PFC circuit 100 to be closer to the waveform of the output reference voltage Vref, thereby improving the accuracy and reliability of the output of the totem pole PFC circuit 100.

[0076] In some embodiments, the current loop compensator 1321 can use proportional resonant control (PR) to complete the compensation of the first current signal. For the current loop compensator 1321, the signal of the object to be compensated is a power frequency sine wave, which cannot be accurately tracked by using a proportional integral link (PI). Therefore, using a proportional resonant control (PR) can also improve the reliability of the current loop compensator 1321.

[0077] In some embodiments, the current modulation unit 132 also includes: a saturation limiter 1323, the saturation limiter 1323 is electrically connected to the current loop compensator 1321, and the input end of the saturation limiter 1323 receives a second current signal. When the current value of the second current signal is less than the current value of the second preset current value information in the saturation limiter 1323, the second current signal is controlled to be transmitted to the PWM generator 1322; when the current value of the second current signal is greater than the current value of the second preset current value information in the saturation limiter 1323, the second preset current value information is controlled to be transmitted as the second current signal to the PWM generator 1322.

[0078] The saturation limiter 1323 is used to limit the maximum current output by the current loop compensator 1321, thereby avoiding safety hazards caused by excessive current output by the current loop compensator 1321. The saturation limiter 1323 can improve the reliability and safety of the totem pole PFC circuit 100 control system.

[0079] In some embodiments, the second control module 102 further includes: a notch filter 142, which is connected between the detection unit 112 and the voltage modulation unit 122 to filter the first voltage signal. For the first voltage signal, an AC component with twice the power frequency must be superimposed on the first voltage signal. After this component enters the voltage modulation unit 122, it will reduce the stability of the current reference signal output by the voltage modulation unit 122. Therefore, filtering the first voltage signal through the notch filter 142 can filter out this part of the AC component, thereby improving the stability of the control system of the totem pole PFC circuit 100 control system.

[0080] In some embodiments, the first duty cycle is increased from the first initial duty cycle with a fixed step length for each pulse cycle, or the step length of the first duty cycle for each pulse cycle is a geometric progression, and / or the second duty cycle is increased from the second initial duty cycle with a fixed step length for each pulse cycle, or the step length of the second duty cycle for each pulse cycle is a geometric progression. By setting the first duty cycle to increase from the first initial duty cycle with a fixed step length for each pulse cycle, and / or the second duty cycle to increase from the second initial duty cycle with a fixed step length for each pulse cycle, a fixed step length can be preset, thereby reducing the computing power required to control the first duty cycle and / or the second duty cycle; by setting the step length of the first duty cycle for each pulse cycle to increase in a geometric progression, and / or the step length of the second duty cycle for each pulse cycle to increase in a geometric progression, the time required for the first duty cycle and / or the second duty cycle to increase to the corresponding target duty cycle can be reduced, thereby improving the control speed of the totem pole PFC circuit 100 control system.

[0081] For example, when the first duty cycle increases from the first initial duty cycle in a fixed step size in each pulse cycle, the first initial duty cycle is 0.1, and the fixed step size is 0.1, the first target duty cycle is 0.5, and the first initial duty cycle will increase to the first target duty cycle after 4 pulse cycles. When the step size of the first duty cycle increasing in each pulse cycle is a geometric progression, the first initial duty cycle is 0.1, and after another pulse cycle, the first initial duty cycle becomes 0.2. After the second pulse cycle, the first initial duty cycle becomes 0.4. After the third pulse cycle hole, the first initial duty cycle becomes 0.8. In other words, the step size of each pulse cycle is a geometric progression with a common ratio of 2. Similarly, the second duty cycle can also increase as in the example of the first duty cycle above.

[0082] In some embodiments, the first duty cycle and the second duty cycle can also increase by taking the average of the target duty cycle. For example, the first initial duty cycle is 0.1 and the target duty cycle is 0.5. Then after one pulse cycle, the first initial duty cycle increases to (0.1+0.5) / 2. After the second pulse cycle, the first initial duty cycle increases to ((0.1+0.5) / 2+0.5) / 2, and so on. It should be noted that / represents division in mathematical symbols.

[0083] It should be noted that the above examples are only for ease of understanding and are not intended to limit the step size added to each pulse cycle. It should be noted that the above embodiments are all described with the high-frequency tube and the power-frequency tube corresponding to the position shown in Figure x. In fact, the positions corresponding to the two high-frequency tubes can be swapped, and the positions corresponding to the two power-frequency tubes can also be swapped. Only simple reasoning based on the corresponding positions is required to obtain the corresponding solution, which also falls within the protection scope of the present disclosure.

[0084] refer to Figure 5 , Figure 5 The green one in the middle is the waveform of the input AC power Vac, and the red one is the waveform of the current iL flowing through the PFC inductor. It can be seen that the embodiment of the present disclosure can control the phase of the current waveform flowing through the PFC inductor L1 to be the same as the phase of the input AC power Vac waveform, and when the input AC power Vac is in the zero-crossing switching state, the current flowing through the PFC inductor L1 has a small fluctuation, which can significantly reduce the current spike and significantly improve THD (Total Harmonic Distortion).

[0085] The embodiment of the present disclosure controls the pulse width of the main switch tube to gradually increase from a very small value when the totem pole PFC circuit 100 is in a zero-crossing switching state, so that the synchronous tube completes reverse recovery, thereby eliminating the current spike on the PFC inductor L1. After the main switch tube completes the soft-start process, the synchronous tube is controlled to complete the soft-start process to eliminate the current spike caused by the load voltage. Moreover, the embodiment of the present disclosure uses the first control module 101 to control the soft-start process of the main switch tube and the synchronous tube during the period when the totem pole PFC circuit is in the zero-crossing switching state, thereby further improving the stability of the output voltage of the totem pole PFC circuit 100 and further improving the current spike problem of the totem pole PFC circuit.

[0086] Another embodiment of the present disclosure further provides a totem pole PFC circuit control method, which can be controlled by the above-mentioned totem pole PFC circuit control system. The totem pole PFC circuit control method provided by another embodiment of the present disclosure will be described below in conjunction with the accompanying drawings. It should be noted that the parts that are the same as or corresponding to the above-mentioned embodiments can refer to the above-mentioned embodiments and will not be repeated below.

[0087] In some embodiments, a totem pole PFC circuit control method may include: providing a totem pole PFC circuit, the totem pole PFC circuit including a zero-crossing switching state and a non-zero-crossing switching state divided according to a phase of an input alternating current.

[0088] The totem pole PFC circuit control method may further include: while the totem pole PFC circuit is in a zero-crossing switching state, controlling the first control module to drive the first control signal of the main switch tube to gradually increase the first duty cycle from the first initial duty cycle to the first target duty cycle, and after the first duty cycle increases to the first target duty cycle, controlling the second duty cycle of the second control signal driving the synchronous tube to gradually increase from the second initial duty cycle to the second target duty cycle, and during the period when the second duty cycle increases, the first duty cycle gradually decreases.

[0089] The totem pole PFC circuit control method may further include: when the totem pole PFC circuit is in a non-zero-crossing switching state, controlling the second control module to drive the voltage value of the totem pole PFC circuit output voltage to be within a preset range, wherein after the first duty cycle increases to the first target duty cycle, the main switch tube is controlled by the second control module, and after the second duty cycle increases to the second target duty cycle, the synchronous tube is controlled by the second control module.

[0090] On the one hand, during the period when the totem pole PFC circuit is in the zero-crossing switching state, the first duty cycle of the first control signal controlling the main switch tube is gradually increased from the first initial duty cycle to the first target duty cycle, and the synchronous tube has been implemented to complete reverse recovery, so as to eliminate the current spike on the PFC inductor. Then, the second duty cycle of the second control signal controlling the synchronous tube is gradually increased from the second initial duty cycle to the second target duty cycle, so as to eliminate the current spike caused by the load voltage; on the other hand, during the period when the totem pole PFC circuit is in the zero-crossing switching state, the startup of the main switch tube and the synchronous tube are both controlled by the first control module, and after the startup is completed, they are both controlled by the second control module, which can further improve the peak current phenomenon of the totem pole PFC circuit.

[0091] In some embodiments, during the period when the first duty cycle increases, the synchronous tube is controlled to remain turned off. By controlling the synchronous tube to remain turned off during the period when the first duty cycle increases, on the one hand, the synchronous tube can be prevented from interfering with the start-up of the main switch tube and avoiding the occurrence of a short circuit, and on the other hand, the synchronous tube can be ensured to complete reverse recovery, thereby improving the reliability of the output voltage of the totem pole PFC circuit.

[0092] In some embodiments, the time required for the first duty cycle to increase to the first target duty cycle is the first time, and the interval time between controlling the start of the main switch tube and the synchronous tube is greater than the first time. In other words, the synchronous tube is controlled to start only after it is determined that the first duty cycle of the main switch tube increases to the first target duty cycle. The synchronous tube can be controlled to start immediately after it is determined that the first duty cycle of the main switch tube increases to the first target duty cycle, or the synchronous tube can be started after several pulse cycles after the first duty cycle of the main switch tube increases to the first target duty cycle, thereby ensuring that the main switch tube completes the soft start process.

[0093] In some embodiments, the totem pole PFC circuit includes: a first high frequency tube and a second high frequency tube, the first duty cycle gradually increases from a first initial duty cycle to a first target duty cycle, and after the first duty cycle increases to the first target duty cycle, the second duty cycle is controlled to gradually increase from the second initial duty cycle to the second target duty cycle, including: if the zero-crossing switching state is that the voltage of the alternating current at the input end of the totem pole PFC circuit switches from a negative half cycle to a positive half cycle, the second high frequency tube serves as a main switch tube, the first duty cycle of the second high frequency tube gradually increases from the first initial duty cycle to the first target duty cycle, and in the second high frequency tube After the first duty cycle of the high-frequency tube increases to the first target duty cycle, the second duty cycle of the first high-frequency tube is controlled to gradually increase from the second initial duty cycle to the second target duty cycle; if the zero-crossing switching state is that the voltage of the alternating current at the input end of the totem pole PFC circuit switches from the positive half cycle to the negative half cycle, the first high-frequency tube is used as the main switch tube, and the first duty cycle of the first high-frequency tube is gradually increased from the first initial duty cycle to the first target duty cycle, and after the first duty cycle of the first high-frequency tube increases to the first target duty cycle, the second duty cycle of the second high-frequency tube is controlled to gradually increase from the second initial duty cycle to the second target duty cycle. The first high-frequency tube and the second high-frequency tube are correspondingly controlled according to different zero-crossing switching states to eliminate the positive current spikes and negative current spikes generated in different periods respectively, so as to improve the reliability of the output of the totem pole PFC circuit.

[0094] In some embodiments, during the period when the voltage of the alternating current at the input end of the totem pole PFC circuit switches from the negative half-cycle to the positive half-cycle, before the second duty cycle increases to the second target duty cycle, the first power frequency tube directly electrically connected to the synchronization tube is controlled to remain turned on, and the second power frequency tube directly electrically connected to the main switch tube is controlled to remain turned off; after the second duty cycle increases to the second target duty cycle, the first power frequency tube is controlled to be turned off, and the second power frequency tube is controlled to be turned on after a preset time interval.

[0095] Before the second duty cycle increases to the second target duty cycle, the second high-frequency tube serves as the main switch tube, and the second power-frequency tube directly electrically connected to the second high-frequency tube remains disconnected; the first high-frequency tube serves as the synchronous tube, and the first power-frequency tube directly electrically connected to the first high-frequency tube remains turned on; the second power-frequency tube remains disconnected to eliminate the positive spike of the PFC inductor current; and, after the second duty cycle increases to the second target duty cycle, the first power-frequency tube is controlled to be disconnected, and the second power-frequency tube is controlled to be turned on after a preset time interval, to ensure that the first power-frequency tube and the second power-frequency tube are completely staggered in turn-on time, thereby avoiding safety hazards in the totem pole PFC circuit.

[0096] Similarly, during the period when the voltage of the alternating current at the input end of the totem pole PFC circuit switches from the positive half cycle to the negative half cycle, the first high-frequency tube serves as the main switch tube, the second high-frequency tube serves as the synchronous tube, the first duty cycle is the duty cycle of the first high-frequency tube, the second duty cycle is the duty cycle of the second high-frequency tube, and before the second duty cycle of the second high-frequency tube increases to the second target duty cycle, the first power-frequency tube directly electrically connected to the first high-frequency tube remains disconnected, and the second power-frequency tube directly electrically connected to the second high-frequency tube remains turned on. After the second duty cycle of the second high-frequency tube increases to the second target duty cycle, the second power-frequency tube is controlled to be disconnected, and the first power-frequency tube is controlled to be turned on at the sum of the preset intervals.

[0097] It should be noted that the direct electrical connection here means that two components are directly connected through a wire, and the two components are not indirectly connected via a third component.

[0098] In some embodiments, while the first duty cycle gradually increases from a first initial duty cycle to a first target duty cycle, the first duty cycle is increased pulse cycle by pulse cycle with a first fixed step size, and / or, while the second duty cycle gradually increases from a second initial duty cycle to a second target duty cycle, the second duty cycle is increased pulse cycle by pulse cycle with a second fixed step size.

[0099] By setting the first duty cycle and / or the second duty cycle to increase pulse cycle by pulse cycle with a fixed step size, the control difficulty of the totem pole PFC circuit control method can be reduced, and there is no need to repeatedly calculate the increment of the duty cycle of each pulse cycle, so as to save the computing power required to complete the totem pole PFC circuit control method.

[0100] In some embodiments, the first fixed step length is equal to the second fixed step length. By controlling the first fixed step length to be equal to the second fixed step length, the control difficulty of the totem pole PFC circuit control method can be reduced, thereby saving the computing power required to complete the totem pole PFC circuit control method.

[0101] refer to Figure 6 , Figure 6 A zero-crossing switching state provided by an embodiment of the present disclosure is a timing diagram of the parts corresponding to the voltage of the alternating current at the input end of the totem pole PFC circuit switching from the negative half-cycle to the positive half-cycle.

[0102] The second high-frequency tube S2 performs soft start in the time period from TO to T1, and the soft start process is completed at T1 time. Thereafter, the switch duty cycle of the second high-frequency tube S2 is controlled by the second control module. After T1 time, the first high-frequency tube S1 performs soft start, and the soft start process is completed at T2 time. Thereafter, the first high-frequency tube S1 is controlled by the second control module. After the first high-frequency tube completes the soft start, the first power frequency tube S3 is turned off, and thereafter, the second power frequency tube S4 is turned on after T3 time.

[0103] refer to Figure 7 , Figure 7 This is a flow chart of a totem pole PFC circuit control method provided by an embodiment of the present disclosure. Figure 7 A totem pole PFC circuit control method provided by an embodiment of the present disclosure is described in detail.

[0104] A first control signal and a second control signal are generated according to the first current signal and the first voltage signal, and it is determined whether it is in a zero-crossing state at this time. When it is in a zero-crossing state, it is determined whether it is a positive zero-crossing or a negative zero-crossing. When it is determined that it is a positive zero-crossing, the second high-frequency tube is used as the main switch tube to perform soft start. After the second high-frequency tube completes the soft start, the first high-frequency tube starts the soft start. After the first high-frequency tube completes the soft start, the first power-frequency tube is turned off and the second power-frequency tube is turned on. When it is determined that it is a negative zero-crossing, the first high-frequency tube is used as the main switch tube to perform soft start. When the first high-frequency tube completes the soft start, the first power-frequency tube is turned off and the second power-frequency tube is turned on. After the first high-frequency tube completes the soft start, the second high-frequency tube starts the soft start. After the second high-frequency tube completes the soft start, the second power-frequency tube is turned off and the first power-frequency tube is turned on. When in a non-zero-crossing state, it is determined whether it is in a positive half-cycle or a negative half-cycle. When in a positive half-cycle, the second high-frequency tube is used as the main switch tube and works at a duty cycle of D, and the first high-frequency tube is used as a synchronous tube and works at a duty cycle of 1-D. When in a negative half-cycle, the first high-frequency tube is used as the main switch tube and works at a duty cycle of D, and the second high-frequency tube is used as a synchronous tube and works at a duty cycle of 1-D.

[0105] Those skilled in the art can understand that the above-mentioned embodiments are specific examples for implementing the present disclosure, and in practical applications, various changes can be made to them in form and detail without departing from the spirit and scope of the embodiments of the present disclosure. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the embodiments of the present disclosure, so the protection scope of the embodiments of the present disclosure shall be based on the scope defined in the claims.

Claims

1. A totem pole PFC circuit control system, characterized in that: include: A totem pole PFC circuit, wherein the totem pole PFC circuit includes a zero-crossing switching state and a non-zero-crossing switching state divided according to the phase of the input alternating current; a first control module, the first control module being electrically connected to the totem pole PFC circuit, and being used for, when the totem pole PFC circuit is in the zero-crossing switching state, controlling a first duty cycle of a first control signal driving a main switch tube to gradually increase from a first initial duty cycle to a first target duty cycle, and after the first duty cycle increases to the first target duty cycle, controlling a second duty cycle of a second control signal driving a synchronous tube to gradually increase from a second initial duty cycle to a second target duty cycle, wherein during the zero-crossing switching state, at most one of the main switch tube and the synchronous tube is turned on at the same time; a second control module, the second control module being electrically connected to the totem pole PFC circuit and configured to control a voltage value of an output voltage of the totem pole PFC circuit to be within a preset range when the totem pole PFC circuit is in the non-zero-crossing switching state; After the first duty cycle increases to the first target duty cycle, the main switch tube is controlled by the second control module, and after the second duty cycle increases to the second target duty cycle, the synchronization tube is controlled by the second control module.

2. The totem pole PFC circuit control system according to claim 1, characterized in that: The second control module includes: a detection unit, the detection unit acquires the first duty cycle, generates and outputs a first current signal and a first voltage signal, the first current signal is a current value flowing through the PFC inductor, and the first voltage signal is an output voltage of the totem pole PFC circuit; a voltage modulation unit, electrically connected to the detection unit, configured to receive the first voltage signal and obtain an alternating current signal at an input end of the totem pole PFC circuit, and generate and output a current reference signal according to an output reference voltage of the totem pole PFC circuit; The current modulation unit is electrically connected to the detection unit and the voltage modulation unit, and is used to receive the first current signal and the current reference signal, and generate and output the first control signal and the second control signal for controlling the main switch tube and the synchronous tube.

3. The totem pole PFC circuit control system according to claim 2, characterized in that: The voltage modulation unit includes: a voltage loop compensator, the voltage loop compensator is electrically connected to the detection unit, and is used to receive the first voltage signal, and generate and output current value information corresponding to the current reference signal according to the output reference voltage of the totem pole PFC circuit; a phase compensator, wherein the phase compensator obtains an alternating current signal at an input end of the totem pole PFC circuit, generates and outputs phase information corresponding to the current reference signal; An integrator is electrically connected to the voltage loop compensator and the phase compensator, obtains the current value information generated by the voltage loop compensator and the phase information generated by the phase compensator, and generates and outputs the current reference signal.

4. The totem pole PFC circuit control system according to claim 3, characterized in that: The phase compensator comprises: A SOGI phase-locked loop, wherein the SOGI phase-locked loop receives an AC signal at an input end of the totem pole PFC circuit; an absolute value compensation circuit, the absolute value compensation circuit receiving an AC signal at an input end of the totem pole PFC circuit; and a mode selector, the mode selector being electrically connected to an output end of the SOGI phase-locked loop and an output end of the absolute value compensation circuit, and selecting one of the SOGI phase-locked loop and the absolute value compensation circuit to be turned on with the integrator.

5. The totem pole PFC circuit control system according to claim 3, characterized in that: The voltage modulation unit also includes: a fast start unit, which is electrically connected to the voltage loop compensator, and has first preset current value information. The fast start unit also obtains the current value information output by the voltage loop compensator, and superimposes the first preset current value information on the current value information output by the voltage loop compensator, and outputs the superimposed information as the current value information of the current reference signal to the integrator.

6. The totem pole PFC circuit control system according to claim 2, characterized in that: The current modulation unit includes: a direction determination instrument, which is electrically connected to the detection unit and is used to receive the first current signal and determine the direction of the first current signal; a current loop compensator, the current loop compensator being electrically connected to the direction determination instrument and the voltage modulation unit, receiving the first current signal and the current reference signal, and generating a second current signal according to the direction of the first current signal; A PWM generator is electrically connected to the current loop compensator, receives the second current signal, generates and outputs the first control signal and the second control signal.

7. The totem pole PFC circuit control system according to claim 6, characterized in that: The current modulation unit further includes: A saturation limiter, wherein the saturation limiter is electrically connected to the current loop compensator, and an input end of the saturation limiter receives the second current signal. When a current value of the second current signal is less than a current value of a second preset current value information in the saturation limiter, the second current signal is controlled to be transmitted to the PWM generator; when a current value of the second current signal is greater than a current value of the second preset current value information in the saturation limiter, the second preset current value information is controlled to be transmitted as a second current signal to the PWM generator.

8. The totem pole PFC circuit control system according to claim 2, characterized in that: The second control module also includes: A notch filter is connected between the detection unit and the voltage modulation unit to filter the first voltage signal.

9. The totem pole PFC circuit control system according to claim 1, characterized in that: The first duty cycle increases from the first initial duty cycle at a fixed step size for each pulse period, or the step size of the first duty cycle increasing per pulse period forms a geometric progression, and / or the second duty cycle increases from the second initial duty cycle at a fixed step size for each pulse period, or the step size of the second duty cycle increasing per pulse period forms a geometric progression.

10. A totem pole PFC circuit control method, characterized in that: include: Providing a totem pole PFC circuit, the totem pole PFC circuit comprising a zero-crossing switching state and a non-zero-crossing switching state divided according to the phase of the input alternating current; During the period when the totem pole PFC circuit is in the zero-crossing switching state, the first control module is controlled to drive the first control signal of the main switch tube to gradually increase the first duty cycle from the first initial duty cycle to the first target duty cycle, and after the first duty cycle increases to the first target duty cycle, the second duty cycle of the second control signal driving the synchronous tube is controlled to gradually increase from the second initial duty cycle to the second target duty cycle, and the first duty cycle gradually decreases during the period when the second duty cycle increases; When the totem pole PFC circuit is in the non-zero-crossing switching state, controlling the second control module to drive the voltage value of the totem pole PFC circuit output voltage to be within a preset range; After the first duty cycle increases to the first target duty cycle, the main switch tube is controlled by the second control module, and after the second duty cycle increases to the second target duty cycle, the synchronization tube is controlled by the second control module.

11. The totem pole PFC circuit control method according to claim 10, characterized in that: During the period when the first duty cycle increases, the synchronous tube is controlled to remain turned off.

12. The totem pole PFC circuit control method according to claim 10, characterized in that: The time required for the first duty cycle to increase to the first target duty cycle is the first time, and the interval time between the start-up of the main switch tube and the synchronization tube is controlled to be greater than the first time.

13. The totem pole PFC circuit control method according to claim 10, characterized in that: During the period when the voltage of the alternating current at the input end of the totem pole PFC circuit switches from the negative half-cycle to the positive half-cycle, before the second duty cycle increases to the second target duty cycle, the first power frequency tube directly electrically connected to the synchronous tube is controlled to remain turned on, and the second power frequency tube directly electrically connected to the main switch tube is controlled to remain turned off; after the second duty cycle increases to the second target duty cycle, the first power frequency tube is controlled to be turned off, and the second power frequency tube is controlled to be turned on after a preset time interval.

14. The totem pole PFC circuit control method according to claim 10, characterized in that: The totem pole PFC circuit includes: a first high-frequency tube and a second high-frequency tube, the first duty cycle is gradually increased from the first initial duty cycle to the first target duty cycle, and after the first duty cycle is increased to the first target duty cycle, the second duty cycle is controlled to gradually increase from the second initial duty cycle to the second target duty cycle, including: If the zero-crossing switching state is that the voltage of the alternating current at the input end of the totem pole PFC circuit switches from a negative half cycle to a positive half cycle, the second high-frequency tube serves as the main switch tube, the first duty cycle of the second high-frequency tube gradually increases from the first initial duty cycle to the first target duty cycle, and after the first duty cycle of the second high-frequency tube increases to the first target duty cycle, the second duty cycle of the first high-frequency tube is controlled to gradually increase from the second initial duty cycle to the second target duty cycle; If the zero-crossing switching state is that the voltage of the alternating current at the input end of the totem pole PFC circuit switches from a positive half-cycle to a negative half-cycle, the first high-frequency tube serves as the main switch tube, and the first duty cycle of the first high-frequency tube gradually increases from the first initial duty cycle to the first target duty cycle, and after the first duty cycle of the first high-frequency tube increases to the first target duty cycle, the second duty cycle of the second high-frequency tube is controlled to gradually increase from the second initial duty cycle to the second target duty cycle.

15. The totem pole PFC circuit control method according to claim 10 or 14, characterized in that: During the period when the first duty cycle gradually increases from the first initial duty cycle to the first target duty cycle, the first duty cycle is increased pulse by pulse cycle with a first fixed step size, and / or, during the period when the second duty cycle gradually increases from the second initial duty cycle to the second target duty cycle, the second duty cycle is increased pulse by pulse cycle with a second fixed step size.

16. The totem pole PFC circuit control method according to claim 15, characterized in that: The first fixed step length is equal to the second fixed step length.

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