Power factor correction boost circuit, control method thereof, control equipment and medium

Abstract

The invention discloses a power factor correction booster circuit, a control method thereof, control equipment and a medium. The power factor correction booster circuit comprises a charging inductor, the charging inductor comprises a magnetic core assembly and a coil wound on the magnetic core assembly, and the magnetic core assembly is provided with an equivalent air gap changing along with the input current of the charging inductor; the output diode, the charging inductor and the output diode are sequentially connected in series between the positive input end and the positive output end; the output capacitor is connected in parallel between the positive output end and the negative output end; the switching tube is connected between the inductor output end and the negative electrode input end of the charging inductor; and the control circuit is connected with the control end of the switching tube, and the control circuit is configured to configure the switching frequency matched with the actual equivalent air gap of the magnetic core assembly to the switching tube according to the input current. According to the power factor correction booster circuit provided by the embodiment of the invention, the efficiency of the power factor correction booster circuit in a non-full-load state can be improved.

Description

Technical Field

[0001] The present application relates to the field of power supply circuits, and in particular to a power factor correction boost circuit and a control method, control device, and medium thereof. Background Art

[0002] The power factor correction (PFC) boost circuit is a non-isolated power factor correction circuit, usually located between the rectifier bridge and the DC / DC (direct current / direct current) converter. It can shape the distorted current provided by the grid into a sinusoidal current that is approximately in phase with the grid voltage, thereby improving the power factor.

[0003] The PFC boost circuit includes a charging inductor and a controllable switch tube, wherein the control mode of the switch tube includes a continuous conduction mode (CCM). In this mode, the switching frequency of the switch tube is a fixed frequency, which is usually matched with the PFC boost circuit being in a full load state. However, when the PFC boost circuit is not in a full load state, the efficiency of the PFC boost circuit is low. Summary of the invention

[0004] The present application provides a power factor correction boost circuit and a control method, a control device, and a medium thereof, which improve the efficiency of the power factor correction boost circuit under a non-full load state.

[0005] In the first aspect, an embodiment of the present application provides a power factor correction boost circuit, which includes: a charging inductor, the charging inductor includes a magnetic core component and a coil wound on the magnetic core component, the magnetic core component is configured to have an equivalent air gap that changes with the input current of the input charging inductor; an output diode, the charging inductor and the output diode are connected in series between the positive input terminal and the positive output terminal in sequence; an output capacitor, connected in parallel between the positive output terminal and the negative output terminal; a switching tube, connected between the inductor output terminal and the negative input terminal of the charging inductor; and a control circuit, connected to the control end of the switching tube, the control circuit is configured to configure a switching frequency that matches the actual equivalent air gap of the magnetic core component to the switching tube according to the input current.

[0006] According to the aforementioned embodiment of the first aspect of the present application, the magnetic core assembly includes a first magnetic core and a second magnetic core, the first magnetic core is arranged in a semi-circular shape to have an opening, the first magnetic core has a first end and a second end opposite to each other at the opening, the second magnetic core is arranged in the opening and connected between the first end and the second end, the cross-sectional area of ​​the second magnetic core gradually increases in the direction from the first end to the second end, and the saturation magnetic flux density of the second magnetic core is less than the saturation magnetic flux density of the first magnetic core.

[0007] According to any of the aforementioned embodiments of the first aspect of the present application, the cross-sectional area of ​​the second magnetic core gradually increases in a step-like manner in the direction from the first end to the second end, so that the magnetic core component has an equivalent air gap that increases in a step-like manner as the input current of the input charging inductor increases.

[0008] According to any of the aforementioned embodiments of the first aspect of the present application, the actual load power of the power factor correction boost circuit has multiple load levels corresponding to the number of steps of the second magnetic core, the switching frequency of the switch tube has multiple frequency levels corresponding one-to-one to the multiple load levels, and the control circuit is configured to control the switch tube to operate at the corresponding frequency level according to the load level where the actual load power is located, wherein the ratio of the power value of each load level to the full load power value is equal to the ratio of the frequency value of the corresponding frequency level to the full load switching frequency value, the full load power value is the load power of the power factor correction boost circuit when it is in a full load state, and the full load switching frequency value is the preset switching frequency corresponding to the power factor correction boost circuit when it is in a full load state.

[0009] According to any of the aforementioned embodiments of the first aspect of the present application, the cross-sectional area of ​​the second magnetic core gradually increases linearly from the first end to the second end, so that the magnetic core component has a linearly increasing equivalent air gap as the input current of the input charging inductor increases.

[0010] According to any of the aforementioned embodiments of the first aspect of the present application, the control circuit is configured to configure a switching frequency that matches the actual equivalent air gap of the magnetic core component to the switching tube based on the ratio of the actual load power of the power factor correction boost circuit to the full load power value, and the actual load power is obtained based on the input current.

[0011] According to any of the aforementioned embodiments of the first aspect of the present application, the control circuit includes: an input current acquisition module, connected to the charging inductor, for acquiring the input current of the input charging inductor; a control execution module, connected to the input current acquisition module and the control end of the switching tube, for sending a drive signal to the switching tube, the drive signal is used to control the switching tube to operate in a continuous conduction mode, and the drive signal is configured with a switching frequency that matches the actual equivalent air gap of the magnetic core component according to the input current.

[0012] In the second aspect, an embodiment of the present application provides a control method for a power factor correction boost circuit, which is applied to the power factor correction boost circuit of any of the aforementioned embodiments. The control method of the power factor correction boost circuit includes: obtaining the input current of the input charging inductor; configuring a switching frequency that matches the actual equivalent air gap of the magnetic core component to the switch tube according to the input current, and controlling the switch tube to operate in a continuous conduction mode.

[0013] According to any of the aforementioned embodiments of the second aspect of the present application, the magnetic core assembly includes a first magnetic core and a second magnetic core, the first magnetic core is arranged in a semi-circular shape to have an opening, the first magnetic core has a first end and a second end opposite to each other at the opening, the second magnetic core is arranged in the opening and connected between the first end and the second end, the cross-sectional area of ​​the second magnetic core gradually increases in a direction from the first end to the second end, the saturation magnetic flux density of the second magnetic core is less than the saturation magnetic flux density of the first magnetic core, and the cross-sectional area of ​​the second magnetic core gradually increases in a step-like manner in a direction from the first end to the second end, and the switching frequency configured to the switch tube according to the input current to match the actual equivalent air gap of the magnetic core assembly includes: obtaining the load gear at which the actual load power of the power factor correction boost circuit is located, wherein the preset number of the load gears corresponds to the number of steps of the second magnetic core, and the actual load power is obtained according to the input current; controlling the switch tube to operate at a corresponding frequency gear according to the load gear at which the actual load power is located, wherein the frequency gear corresponds one-to-one to the load gear.

[0014] According to any of the aforementioned implementations of the second aspect of the present application, the ratio of the power value of each load gear to the full-load power value is equal to the ratio of the frequency value corresponding to the frequency gear to the full-load switching frequency value, the full-load power value is the load power when the power factor correction boost circuit is in a full-load state, and the full-load switching frequency value is the preset switching frequency corresponding to the power factor correction boost circuit in a full-load state.

[0015] According to any of the aforementioned embodiments of the second aspect of the present application, the magnetic core assembly includes a first magnetic core and a second magnetic core, the first magnetic core is arranged in a semi-circular shape to have an opening, the first magnetic core has a first end and a second end opposite to each other at the opening, the second magnetic core is arranged in the opening and connected between the first end and the second end, the cross-sectional area of ​​the second magnetic core gradually increases from the first end to the second end, the saturation magnetic flux density of the second magnetic core is less than the saturation magnetic flux density of the first magnetic core, and the cross-sectional area of ​​the second magnetic core gradually increases linearly from the first end to the second end, and the switching frequency configured to match the actual equivalent air gap of the magnetic core assembly according to the input current includes: configuring the switching frequency to match the actual equivalent air gap of the magnetic core assembly to the switching tube according to the ratio of the actual load power to the full load power value of the power factor correction boost circuit, and the actual load power is obtained according to the input current.

[0016] In a third aspect, an embodiment of the present application provides a switch tube control device, the switch tube control device comprising a memory and at least one processor, the memory being electrically connected to the at least one processor, the memory storing instructions, and the at least one processor calling the instructions in the memory so that the switch tube control device executes a control method for a power factor correction boost circuit according to any of the aforementioned embodiments of the second aspect of the present application.

[0017] In a fourth aspect, an embodiment of the present application provides a computer-readable storage medium having instructions stored thereon, which, when executed by a processor, implements a control method for a power factor correction boost circuit according to any of the aforementioned embodiments of the second aspect of the present application.

[0018] According to the power factor correction boost circuit of the embodiment of the present application, its charging inductor includes a magnetic core component and a coil wound on the magnetic core component, wherein the magnetic core component is configured to have an equivalent air gap that changes with the input current of the input charging inductor. When the power factor correction boost circuit is in a state of large load, that is, in a heavy load state, the input current is higher, at this time, the equivalent air gap increases, the inductance of the charging inductor decreases, and the saturation flux density of the magnetic core component decreases, so the loss of the magnetic core component is reduced in the heavy load state. In the power factor correction boost circuit of the embodiment of the present application, the control circuit is connected to the control end of the switch tube, and the control circuit is configured to configure the switch tube with a switching frequency that matches the actual equivalent air gap of the magnetic core component according to the input current. When the actual load power is large, that is, when it is heavy loaded, the input current is large, the equivalent air gap is large, and accordingly, a higher switching frequency is matched to the switch tube. When the actual load power is small, that is, when it is lightly loaded, the input current is small, the equivalent air gap is small, and accordingly, a lower switching frequency is matched to the switch tube. Since the loss of the power factor correction boost circuit is mainly caused by the loss of the switch tube when the load is light, the loss of the switch tube can be significantly reduced by configuring a lower switching frequency for the switch tube when the load is light. Therefore, even if the power factor correction boost circuit is not fully loaded, it has a high efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

[0020] Figure 1 A circuit diagram of an embodiment of a power factor correction boost circuit of the present application;

[0021] Figure 2This is a structural schematic diagram of a magnetic core assembly in an embodiment of a power factor correction boost circuit of the present application;

[0022] Figure 3 This is a structural schematic diagram of a magnetic core assembly in an alternative embodiment of a power factor correction boost circuit of the present application;

[0023] Figure 4 This is a circuit structure diagram of a control circuit in an embodiment of a power factor correction boost circuit of the present application;

[0024] Figure 5 This is a schematic diagram of the hardware structure of an embodiment of the switch tube control device of the present application. DETAILED DESCRIPTION

[0025] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0026] It should be noted that all directional indications in the embodiments of the present application (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0027] In addition, the descriptions of "first", "second", etc. in this application are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in this field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by this application.

[0028] An embodiment of the present application provides a power factor correction (PFC) boost circuit. Figure 1This is a circuit diagram of an embodiment of a power factor correction boost circuit of the present application. The power factor correction boost circuit includes a charging inductor L1, an output diode D1, an output capacitor C1, a switch tube Q1 and a control circuit 110: the charging inductor L1 and the output diode D1 are connected in series between the positive input terminal Vin+ and the positive output terminal Vout+. The output capacitor C1 is connected in parallel between the positive output terminal Vout+ and the negative output terminal Vout-. The switch tube Q1 is connected between the inductor output terminal of the charging inductor L1 and the negative input terminal Vin-. The switch tube Q1 is, for example, a metal oxide semiconductor field effect transistor (Metal-Oxide-SemiconductorField-Effect Transistor, MOSFET) or an insulated gate bipolar transistor (Insulate-Gate Bipolar Transistor, IGBT).

[0029] The charging inductor L1 includes a magnetic core component and a coil wound on the magnetic core component. The magnetic core component is configured to have an equivalent air gap that varies with the input current of the input charging inductor L1. In some embodiments, the magnetic core component is configured to have an equivalent air gap that is proportional to the input current of the input charging inductor L1.

[0030] The control circuit 110 is connected to the control end of the switch tube Q1. The control circuit 110 is configured to configure a switching frequency that matches the actual equivalent air gap of the magnetic core component to the switch tube Q1 according to the input current. The control circuit 110 can be a control chip in the art for switching control of the switch tube Q1 in a PFC boost circuit, and the chip has multiple pins, at least one signal input pin is connected to the inductor input end of the charging inductor L1, and at least one signal output pin is connected to the control end of the switch tube Q1.

[0031] In this embodiment, the inductor input terminal of the charging inductor L1 is connected to the positive input terminal Vin+, the inductor output terminal of the charging inductor L1 is connected to the positive electrode of the output diode D1, and the negative electrode of the output diode D1 is connected to the positive output terminal Vout+ and the output capacitor C1. The first electrode of the switch tube Q1 is connected to the inductor output terminal of the charging inductor L1, the second electrode of the switch tube Q1 is connected to the negative input terminal Vin-, and the control terminal of the switch tube Q1 is connected to the control circuit 110.

[0032] In this embodiment, the driving signal (switch control signal) received by the control end of the switch tube Q1 is a pulse width modulation (PWM) signal.

[0033] In this embodiment, the control mode of the switch tube Q1 is continuous conduction mode (CCM), that is, within a switching cycle, the current in the charging inductor L1 will not drop to zero. Specifically, when the switch tube Q1 is turned on, the AC current passes through the charging inductor L1, and the current in the charging inductor L1 increases. When the switch tube Q1 is turned off, the current stored in the charging inductor L1 supplies power to the output capacitor C1 and the positive output terminal Vout+ through the output diode D1.

[0034] According to the power factor correction boost circuit of the embodiment of the present application, its charging inductor L1 includes a magnetic core component and a coil wound on the magnetic core component, wherein the magnetic core component is configured to have an equivalent air gap that changes with the input current of the input charging inductor L1. When the power factor correction boost circuit is in a state of large load, that is, in a heavy load state, the input current is higher, at this time the equivalent air gap increases, the inductance of the charging inductor L1 decreases, and the saturation magnetic flux density of the magnetic core component decreases, so the loss of the magnetic core component is reduced in the heavy load state. In the power factor correction boost circuit of the embodiment of the present application, the control circuit 110 is connected to the control end of the switch tube Q1, and the control circuit 110 is configured to configure a switching frequency that matches the actual equivalent air gap of the magnetic core component to the switch tube Q1 according to the input current. When the actual load power is large, that is, when it is heavy loaded, the input current is large, the equivalent air gap is large, and accordingly, a higher switching frequency is matched to the switch tube Q1. When the actual load power is small, that is, when it is light loaded, the input current is small, the equivalent air gap is small, and accordingly, a lower switching frequency is matched to the switch tube Q1. Since the loss of the power factor correction boost circuit is mainly the loss of the switch tube Q1 when it is light loaded, by configuring a lower switching frequency for the switch tube Q1 when it is light loaded, the loss of the switch tube Q1 can be significantly reduced. Therefore, even if the power factor correction boost circuit is not fully loaded, it has a high efficiency.

[0035] In this article, full load means that the power factor correction boost circuit is in the maximum power output state, half load means that the correction boost circuit is in the half of the full load state, and light load means that the correction boost circuit is in the state of less than 10% of the full load.

[0036] Figure 2This is a schematic diagram of the structure of a magnetic core assembly in an embodiment of a power factor correction boost circuit of the present application. In some embodiments, the magnetic core assembly 210 includes a first magnetic core 211 and a second magnetic core 212. The first magnetic core 211 is configured to be in a semi-circular shape to have an opening. The first magnetic core 211 has a first end A1 and a second end A2 opposite to each other at the opening K1. The second magnetic core 212 is disposed at the opening K1 and connected between the first end A1 and the second end A2. The cross-sectional area of ​​the second magnetic core 212 gradually increases in the direction from the first end A1 to the second end A2. The material of the second magnetic core 212 is different from that of the first magnetic core 211, so that the saturation magnetic flux density of the second magnetic core 212 is less than the saturation magnetic flux density of the first magnetic core 211.

[0037] The first magnetic core 211 and the second magnetic core 212 can respectively adopt various conventional magnetic core materials, such as iron silicon alloy powder core, ferrite, etc. In one example, the material of the first magnetic core 211 is ferrite. The material of the second magnetic core 212 is different from that of the first magnetic core 211, so that the saturation magnetic flux density of the second magnetic core 212 is less than the saturation magnetic flux density of the first magnetic core 211. Therefore, when the charging inductor is working, as the input current gradually increases, the magnetic flux of the second magnetic core 212 will saturate before the first magnetic core 211, and the second magnetic core 212 of the saturated magnetic flux portion is equivalent to close to the air, so that the equivalent air gap of the magnetic core assembly 210 increases with the increase of the input current.

[0038] Refer to the following formula 1:

[0039] B=(L*I) / (N*AE) Formula 1

[0040] In formula 1, B is the magnetic flux density; L is the inductance; I is the current flowing through the charging inductor (ie, the input current); N is the number of turns of the coil of the charging inductor; and AE is the effective cross-sectional area of ​​the charging inductor.

[0041] According to the power factor correction boost circuit of the above embodiment, the higher the input current, the larger the equivalent air gap of the magnetic core component 210, the lower the inductance of the charging inductor, and the lower the saturation magnetic flux density of the magnetic core component 210, thereby reducing the loss of the magnetic core component 210 under heavy load conditions.

[0042] like Figure 2 In this embodiment, the first magnetic core 211 includes a first splicing portion 211a and a second splicing portion 211b. The first splicing portion 211a and the second splicing portion 211b are both in a semi-circular shape. The first splicing portion 211a and the second splicing portion 211b are spliced ​​together to obtain the first magnetic core 211.

[0043] like Figure 2In some embodiments, the cross-sectional area of ​​the second magnetic core 212 increases gradually in a step-like manner from the first end A1 to the second end A2, so that the magnetic core assembly 210 has an equivalent air gap that increases in a step-like manner as the input current of the input charging inductor L1 increases. The material of the second magnetic core 212 is different from that of the first magnetic core 211. For example, in this embodiment, the second magnetic core 212 includes a first step portion 212a, a second step portion 212b, and a third step portion 212c arranged in sequence from the first end A1 to the second end A2, and the cross-sectional areas of the first step portion 212a, the second step portion 212b, and the third step portion 212c increase in a step-like manner in sequence.

[0044] In the above exemplary embodiment, assuming that the input current is Imax under full load, when the input current is 1 / 4Imax, the magnetic flux of the first step portion 212a is saturated first, and the first step portion 212a is equivalent to air. When the input current is 1 / 2Imax, the magnetic flux of the first step portion 212a and the second step portion 212b is saturated, and the first step portion 212a and the second step portion 212b are equivalent to air. When the input current is 3 / 4Imax, the magnetic flux of the first step portion 212a, the second step portion 212b, and the third step portion 212c is saturated, and the first step portion 212a, the second step portion 212b, and the third step portion 212c are equivalent to air. As the input current increases, the equivalent air gap of the magnetic core component 210 increases proportionally, the inductance of the charging inductance decreases, and the saturation magnetic flux density of the magnetic core component 210 decreases, so that the loss of the magnetic core component 210 is also reduced under heavy load.

[0045] In some embodiments, the actual load power of the power factor correction boost circuit has a plurality of load gears corresponding to the number of steps of the second magnetic core 212, the switching frequency of the switch tube has a plurality of frequency gears corresponding to the plurality of load gears, and the control circuit is configured to control the switch tube to operate at the corresponding frequency gear according to the load gear of the actual load power. The actual load power of the power factor correction boost circuit is obtained according to the input current.

[0046] The ratio of the power value of each load gear to the full-load power value is equal to the ratio of the frequency value of the corresponding frequency gear to the full-load switching frequency value. The full-load power value is the load power when the power factor correction boost circuit is in a full-load state, and the full-load switching frequency value is the preset switching frequency corresponding to the power factor correction boost circuit in a full-load state.

[0047] In this embodiment, it is assumed that the full load power value is Pmax and the full load switching frequency value is Fmax. When the actual load power is a load level of 1 / 4Pmax, the frequency level of the switch tube is controlled to be 1 / 4Fmax with the corresponding inductance. When the actual load power is a load level of 1 / 2Pmax, the frequency level of the switch tube is controlled to be 1 / 2Fmax with the corresponding inductance. When the actual load power is a load level of 3 / 4Pmax, the frequency level of the switch tube is controlled to be 3 / 4Fmax with the corresponding inductance.

[0048] In the above embodiment, different switching frequencies are configured for the switch tube with corresponding inductance under different loads. Therefore, when the load is light, a lower switching frequency is configured for the switch tube, which can significantly reduce the loss of the switch tube. This makes the power factor correction boost circuit have a higher efficiency even under light load conditions.

[0049] Figure 3 This is a schematic diagram of the structure of a magnetic core assembly in an alternative embodiment of a power factor correction boost circuit of the present application. The magnetic core assembly 210 includes a first magnetic core 211 and a second magnetic core 212. The first magnetic core 211 is configured in a semi-circular shape to have an opening K1. The first magnetic core 211 has a first end A1 and a second end A2 opposite to each other at the opening K1. The second magnetic core 212 is disposed at the opening K1 and connected between the first end A1 and the second end A2. The cross-sectional area of ​​the second magnetic core 212 gradually increases in the direction from the first end A1 to the second end A2. The material of the second magnetic core 212 is different from that of the first magnetic core 211, so that the saturation magnetic flux density of the second magnetic core 212 is less than the saturation magnetic flux density of the first magnetic core 211.

[0050] In an alternative embodiment, the cross-sectional area of ​​the second magnetic core 212 increases linearly in the direction from the first end A1 to the second end A2, so that the magnetic core assembly 210 has a linearly increasing equivalent air gap as the input current of the input charging inductor L1 increases. For example, the second magnetic core 212 has a slope structure, wherein the sharp corner of the slope structure of the second magnetic core 212 faces the first end A1. When current passes through the charging inductor, the magnetic flux of the sharp corner of the second magnetic core 212 is first saturated and equivalent to air. As the input current gradually increases, the volume of the magnetic flux saturation of the sharp corner gradually increases, the equivalent air gap increases, and the total equivalent inductance decreases.

[0051] In an alternative embodiment, the control circuit is configured to configure a switching frequency matching the actual equivalent air gap of the magnetic core component to the switch tube according to the ratio of the actual load power of the power factor correction boost circuit to the full load power value, so as to control the switch tube to operate at the switching frequency corresponding to the actual equivalent air gap. The actual load power of the power factor correction boost circuit is obtained according to the input current.

[0052] In the above alternative embodiment, under different input currents, the change of the equivalent air gap causes the inductance to change linearly. Specifically, the inductance can be calibrated by the input current. At this time, the switching frequency of the CCM switch tube is changed in real time by controlling the ripple rate to remain unchanged, forming a closed-loop control.

[0053] Refer to the following formula 2:

[0054] V / L*D*(1 / F)=Kr*Ipeak Formula 2

[0055] In formula 2, V is the voltage across the charging inductor; L is the inductance; D is the duty cycle of the switch tube; F is the switching frequency; Kr is the ripple rate of the charging inductor current; Ipeak is the effective value of the charging inductor current.

[0056] In Formula 2, when the voltage V across the charging inductor and the duty cycle D of the switch tube remain unchanged, the inductance L decreases as the input current increases. At this time, if you want the value of Kr*Ipeak to be smaller (compared to the case where the inductance does not decrease), then according to Formula 2, the switching frequency F needs to be increased accordingly. Since in this embodiment, the inductance L changes linearly under different input currents, the inductance of the charging inductor can be calibrated by the input current, thereby adjusting the switching frequency F so that the ripple rate of the charging inductor current reaches a better value (the smaller the better), and when lightly loaded, the total harmonic distortion rate (Total Harmonic Current Distortion, THDi) of the current is also reduced.

[0057] The control circuit 110 can be a control chip in the art for controlling the switch tube Q1 in the PFC boost circuit. The chip has multiple pins, at least one signal input pin is connected to the inductor input end of the charging inductor L1, and at least one signal output pin is connected to the control end of the switch tube Q1.

[0058] Figure 4 The schematic diagram of the circuit structure of the control circuit in the embodiment of the power factor correction boost circuit of the present application is as follows: The control circuit 110 includes an input current acquisition module 111 and a control execution module 113 .

[0059] The input current acquisition module 111 is connected to the charging inductor, and the input current acquisition module 111 is used to acquire the input current of the input charging inductor. The control execution module 113 is connected to the input current acquisition module 111 and the control end of the switch tube, and the control execution module 113 is used to send a drive signal to the switch tube, and the drive signal is used to control the switch tube to work in a continuous conduction mode, and the drive signal is configured with a switching frequency that matches the actual equivalent air gap of the magnetic core component according to the input current.

[0060] In some embodiments, the control circuit 110 further includes a load calculation module, which is connected to the input current acquisition module 111 and is used to obtain the actual load power of the power factor correction boost circuit according to the input current.

[0061] The embodiment of the present application also provides a control method of a power factor correction boost circuit. The power factor correction boost circuit is applied to the power factor correction boost circuit of any of the above embodiments.

[0062] In this embodiment, the control method of the power factor correction boost circuit includes step S110 and step S120.

[0063] In step S110 , an input current of the input charging inductor is obtained.

[0064] In step S120, a switching frequency matching the actual equivalent air gap of the magnetic core component is configured for the switch tube according to the input current, and the switch tube is controlled to operate in a continuous conduction mode.

[0065] According to the control method of the power factor correction boost circuit of the embodiment of the present application, it is applied to the power factor correction boost circuit of any of the aforementioned embodiments, the charging inductor of the power factor correction boost circuit includes a magnetic core component and a coil wound on the magnetic core component, wherein the magnetic core component is configured to have an equivalent air gap that changes with the input current of the input charging inductor, and when the power factor correction boost circuit is in a state of large load, that is, in a heavy load state, the input current is higher, at this time the equivalent air gap increases, the inductance of the charging inductor decreases, and the saturation flux density of the magnetic core component decreases, so that the loss of the magnetic core component is reduced in the heavy load state. In the control method of the embodiment of the present application, the input current of the input charging inductor is obtained, thereby obtaining the actual load power, and then, according to the input current, the switching tube is configured with a switching frequency that matches the actual equivalent air gap of the magnetic core component, and the switching tube is controlled to operate in a continuous conduction mode. When the actual load power is large, that is, when it is heavy loaded, the input current is large, the equivalent air gap is large, and accordingly, a higher switching frequency is matched to the switch tube. When the actual load power is small, that is, when it is light loaded, the input current is small, the equivalent air gap is small, and accordingly, a lower switching frequency is matched to the switch tube. Since the loss of the power factor correction boost circuit is mainly the loss of the switch tube when it is light loaded, by configuring a lower switching frequency for the switch tube when it is light loaded, the loss of the switch tube can be significantly reduced. Therefore, even if the power factor correction boost circuit is not fully loaded, it has a high efficiency.

[0066] In some embodiments, reference Figure 2, the magnetic core assembly includes a first magnetic core 211 and a second magnetic core 212. The first magnetic core 211 is arranged in a semi-circular shape to have an opening K1. The first magnetic core 211 has a first end A1 and a second end A2 opposite to each other at the opening K1. The second magnetic core 212 is arranged at the opening K1 and connected between the first end A1 and the second end A2. The cross-sectional area of ​​the second magnetic core 212 gradually increases in a step-like manner in the direction from the first end A1 to the second end A2, so that the magnetic core assembly 210 has an equivalent air gap that increases in a step-like manner as the input current of the input charging inductor L1 increases. The material of the second magnetic core 212 is different from that of the first magnetic core 211.

[0067] In some embodiments, the step of configuring the switch tube with a switching frequency that matches the actual equivalent air gap of the magnetic core component according to the input current includes: obtaining the load level at which the actual load power of the power factor correction boost circuit is located, wherein the preset number of load levels corresponds to the number of steps of the second magnetic core; and controlling the switch tube to operate at the corresponding frequency level according to the load level at which the actual load power is located, wherein the frequency level corresponds to the load level one by one. The actual load power of the power factor correction boost circuit is obtained according to the input current.

[0068] In this embodiment, the ratio of the power value of each load gear to the full-load power value is equal to the ratio of the frequency value of the corresponding frequency gear to the full-load switching frequency value. The full-load power value is the load power when the power factor correction boost circuit is in a full-load state, and the full-load switching frequency value is the preset switching frequency corresponding to the power factor correction boost circuit in a full-load state.

[0069] In the above embodiment, the higher the input current, the larger the equivalent air gap of the magnetic core component, the lower the inductance of the charging inductance, and the lower the saturation magnetic flux density of the magnetic core component, so the loss of the magnetic core component is reduced in a heavy load state.

[0070] In the above embodiment, different switching frequencies are configured for the switch tube with corresponding inductance under different loads. Therefore, when the load is light, a lower switching frequency is configured for the switch tube, which can significantly reduce the loss of the switch tube. This makes the power factor correction boost circuit have a higher efficiency even under light load conditions.

[0071] In an alternative embodiment, reference Figure 3, the magnetic core assembly includes a first magnetic core 211 and a second magnetic core 212. The first magnetic core 211 is arranged in a semi-circular shape to have an opening K1. The first magnetic core 211 has a first end A1 and a second end A2 opposite to each other at the opening K1. The second magnetic core 212 is arranged at the opening K1 and connected between the first end A1 and the second end A2. The cross-sectional area of ​​the second magnetic core 212 gradually increases linearly in the direction from the first end A1 to the second end A2, so that the magnetic core assembly 210 has an equivalent air gap that increases linearly with the increase of the input current of the input charging inductor L1. The material of the second magnetic core 212 is different from that of the first magnetic core 211.

[0072] In an alternative embodiment, the step of configuring the switch tube with a switching frequency that matches the actual equivalent air gap of the magnetic core component according to the input current includes: configuring the switch tube with a switching frequency that matches the actual equivalent air gap of the magnetic core component according to the ratio of the actual load power of the power factor correction boost circuit to the full load power value. The actual load power of the power factor correction boost circuit is obtained according to the input current.

[0073] In the above alternative embodiment, under different input currents, the change of the equivalent air gap causes the inductance to change linearly. Specifically, the inductance can be calibrated by the input current. At this time, the switching frequency of the CCM switch tube is changed in real time by controlling the ripple rate to remain unchanged, forming a closed-loop control. By adjusting the switching frequency, the ripple rate of the charging inductor current reaches a more optimal value (the smaller the better), and the THDi is also reduced when the load is light.

[0074] The embodiment of the present application also provides a switch tube control device. In some embodiments, the switch tube control device may be a control device connected to a switch tube of a PFC boost circuit, and the device is used to control the switching of the switch tube.

[0075] Figure 5 This is a hardware structure diagram of an embodiment of a switch tube control device of the present application. The switch tube control device includes a memory 510 and at least one processor 520, and the memory 510 is electrically connected to the at least one processor 520. Instructions are stored in the memory 510, and at least one processor 520 calls the instructions in the memory 510, so that the switch tube control device executes the control method of the power factor correction boost circuit according to any of the aforementioned embodiments of the present application.

[0076] The control method of the power factor correction boost circuit includes: obtaining the input current of the input charging inductor; configuring the switching tube with a switching frequency matching the actual equivalent air gap of the magnetic core component according to the input current, and controlling the switching tube to operate in a continuous conduction mode.

[0077] Specifically, the processor 520 may include a central processing unit (CPU), or an application specific integrated circuit (ASIC), or may be configured to implement one or more integrated circuits of the embodiments of the present application.

[0078] The memory 510 may include a large capacity memory 510 for data or instructions. By way of example and not limitation, the memory 510 may include a hard disk drive (HDD), a floppy disk drive, a flash memory, an optical disk, a magneto-optical disk, a tape, or a universal serial bus (USB) drive, or a combination of two or more of these. Where appropriate, the memory 510 may include a removable or non-removable (or fixed) medium. Where appropriate, the memory 510 may be inside or outside the integrated gateway disaster recovery device. In a specific embodiment, the memory 510 is a non-volatile solid-state memory. In a specific embodiment, the memory 510 includes a read-only memory (ROM). Where appropriate, the ROM may be a mask-programmed ROM, a programmable ROM (PROM), an erasable PROM (EPROM), an electrically erasable PROM (EEPROM), an electrically rewritable ROM (EAROM), or a flash memory, or a combination of two or more of these.

[0079] In one example, the control device may further include a communication interface 530 and a bus 540. The processor 520, the memory 510, and the communication interface 530 are connected via the bus 540 and communicate with each other.

[0080] The communication interface 530 is mainly used to implement communication between various modules, devices, units and / or equipment in the embodiments of the present application.

[0081] Bus 540 includes hardware, software or both, and the parts of online data flow billing equipment are coupled to each other. For example, but not limitation, bus may include accelerated graphics port (AGP) or other graphics bus, enhanced industrial standard architecture (EISA) bus, front-end bus (FSB), hypertransport (HT) interconnection, industrial standard architecture (ISA) bus, infinite bandwidth interconnection, low pin count (LPC) bus, memory 510 bus, micro channel architecture (MCA) bus, peripheral component interconnection (PCI) bus, PCI-Express (PCI-X) bus, serial advanced technology attachment (SATA) bus, video electronics standard association local (VLB) bus or other suitable bus or two or more of these combinations. In appropriate cases, bus 540 may include one or more buses. Although the present application embodiment describes and shows a specific bus, the application considers any suitable bus or interconnection.

[0082] In addition, in combination with the power factor correction boost circuit in the above embodiment, the embodiment of the present application can provide a computer-readable storage medium for implementation. The computer-readable storage medium stores instructions, and when the instructions are executed by the processor, any control method for the power factor correction boost circuit in the above embodiment is implemented.

[0083] The control method of the power factor correction boost circuit includes: obtaining the input current of the input charging inductor; configuring the switching tube with a switching frequency matching the actual equivalent air gap of the magnetic core component according to the input current, and controlling the switching tube to operate in a continuous conduction mode.

[0084] The present application is not limited to the specific configuration and processing described above and shown in the figures. For the sake of simplicity, a detailed description of the known methods is omitted here. In the above embodiments, several specific steps are described and shown as examples. However, the method process of the present application is not limited to the specific steps described and shown, and those skilled in the art can make various changes, modifications and additions, or change the order between the steps after understanding the spirit of the present application.

[0085] The functional blocks shown in the above block diagram can be implemented as hardware, software, firmware or a combination thereof. When implemented in hardware, it can be, for example, an electronic circuit, an application specific integrated circuit (ASIC), appropriate firmware, a plug-in, a function card, etc. When implemented in software, the elements of the present application are programs or code segments that are used to perform the required tasks. The program or code segment can be stored in a machine-readable medium, or transmitted on a transmission medium or a communication link by a data signal carried in a carrier wave. "Machine-readable medium" can include any medium capable of storing or transmitting information. Examples of machine-readable media include electronic circuits, semiconductor memory devices, ROM, flash memory, erasable ROM (EROM), floppy disks, CD-ROMs, optical disks, hard disks, optical fiber media, radio frequency (RF) links, etc. The code segment can be downloaded via a computer network such as the Internet, an intranet, etc.

[0086] It should also be noted that the exemplary embodiments mentioned in this application describe some methods or systems based on a series of steps or devices. However, this application is not limited to the order of the above steps, that is, the steps can be performed in the order mentioned in the embodiment, or in a different order from the embodiment, or several steps can be performed simultaneously.

[0087] The above is only a specific implementation of the present application. Those skilled in the art can clearly understand that for the convenience and simplicity of description, the specific working processes of the systems, modules and units described above can refer to the corresponding processes in the aforementioned method embodiments, and will not be repeated here. It should be understood that the protection scope of the present application is not limited to this. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed in the present application, and these modifications or replacements should be included in the protection scope of the present application.

Claims

1. A power factor correction boost circuit, characterized in that: include: A charging inductor, the charging inductor comprising a magnetic core component and a coil wound on the magnetic core component, the magnetic core component being configured to have an equivalent air gap that varies with an input current input into the charging inductor; An output diode, wherein the charging inductor and the output diode are sequentially connected in series between the positive input terminal and the positive output terminal; An output capacitor connected in parallel between the positive output terminal and the negative output terminal; A switch tube connected between the inductor output terminal and the negative electrode input terminal of the charging inductor; as well as A control circuit is connected to the control end of the switch tube, and the control circuit is configured to configure a switching frequency matching the actual equivalent air gap of the magnetic core component to the switch tube according to the input current.

2. The power factor correction boost circuit according to claim 1, characterized in that: The magnetic core assembly includes a first magnetic core and a second magnetic core, the first magnetic core is arranged in a semi-circular shape to have an opening, the first magnetic core has a first end and a second end opposite to each other at the opening, the second magnetic core is arranged in the opening and connected between the first end and the second end, the cross-sectional area of ​​the second magnetic core gradually increases in the direction from the first end to the second end, and the saturation magnetic flux density of the second magnetic core is less than the saturation magnetic flux density of the first magnetic core.

3. The power factor correction boost circuit according to claim 2, characterized in that: The cross-sectional area of ​​the second magnetic core increases gradually in a step-like manner from the first end to the second end, so that the magnetic core component has an equivalent air gap that increases in a step-like manner as the input current input into the charging inductor increases.

4. The power factor correction boost circuit according to claim 3, characterized in that: The actual load power of the power factor correction boost circuit has a plurality of load levels corresponding to the number of steps of the second magnetic core, the switching frequency of the switch tube has a plurality of frequency levels corresponding to the plurality of load levels one by one, and the control circuit is configured to control the switch tube to operate at the corresponding frequency level according to the load level at which the actual load power is located. Among them, the ratio of the power value of each load gear to the full-load power value is equal to the ratio of the frequency value corresponding to the frequency gear to the full-load switching frequency value, the full-load power value is the load power when the power factor correction boost circuit is in a full-load state, and the full-load switching frequency value is the preset switching frequency corresponding to the power factor correction boost circuit in a full-load state.

5. The power factor correction boost circuit according to claim 2, characterized in that: The cross-sectional area of ​​the second magnetic core increases linearly and gradually in a direction from the first end to the second end, so that the magnetic core component has an equivalent air gap that increases linearly as the input current input into the charging inductor increases.

6. The power factor correction boost circuit according to claim 5, characterized in that: The control circuit is configured to configure the switching frequency that matches the actual equivalent air gap of the magnetic core component to the switching tube according to the ratio of the actual load power of the power factor correction boost circuit to the full load power value, and the actual load power is obtained according to the input current.

7. The power factor correction boost circuit according to claim 1, characterized in that: The control circuit comprises: An input current acquisition module, connected to the charging inductor, and used to acquire the input current input into the charging inductor; A control execution module is connected to the input current acquisition module and the control end of the switch tube, and is used to send a drive signal to the switch tube, wherein the drive signal is used to control the switch tube to operate in a continuous conduction mode, and the drive signal is configured with a switching frequency that matches the actual equivalent air gap of the magnetic core component according to the input current.

8. A control method for a power factor correction boost circuit, characterized in that: Applied to the power factor correction boost circuit according to any one of claims 1 to 7, the control method of the power factor correction boost circuit comprises: Acquiring an input current input into the charging inductor; A switching frequency matching the actual equivalent air gap of the magnetic core component is configured for the switch tube according to the input current, and the switch tube is controlled to operate in a continuous conduction mode.

9. The control method of the power factor correction boost circuit according to claim 8, characterized in that: Applicable to the power factor correction boost circuit as claimed in claim 3, The configuring the switching frequency matching the actual equivalent air gap of the magnetic core component to the switching tube according to the input current comprises: Obtaining a load level at which an actual load power of a power factor correction boost circuit is located, wherein a preset number of load levels corresponds to a number of steps of the second magnetic core, and the actual load power is obtained according to the input current; The switch tube is controlled to operate at a corresponding frequency level according to the load level at which the actual load power is located, wherein the frequency level corresponds to the load level one by one.

10. The control method of the power factor correction boost circuit according to claim 9, characterized in that: The ratio of the power value of each load gear to the full load power value is equal to the ratio of the frequency value of the corresponding frequency gear to the full load switching frequency value. The full-load power value is the load power when the power factor correction boost circuit is in a full-load state, and the full-load switching frequency value is the preset switching frequency corresponding to the power factor correction boost circuit in a full-load state.

11. The control method of the power factor correction boost circuit according to claim 8, characterized in that: Applicable to the power factor correction boost circuit as claimed in claim 5, The configuring the switching frequency matching the actual equivalent air gap of the magnetic core component to the switching tube according to the input current comprises: According to the ratio of the actual load power to the full load power value of the power factor correction boost circuit, the switching frequency matching the actual equivalent air gap of the magnetic core component is configured for the switch tube, and the actual load power is obtained according to the input current.

12. A switch tube control device, characterized in that: The switch tube control device includes a memory and at least one processor, wherein the memory is electrically connected to the at least one processor, and the memory stores instructions. The at least one processor calls the instruction in the memory so that the switch tube control device executes the control method of the power factor correction boost circuit as described in any one of claims 8 to 11.

13. A computer-readable storage medium having instructions stored thereon, characterized in that: When the instructions are executed by the processor, the control method of the power factor correction boost circuit as described in any one of claims 8 to 11 is implemented.

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