A current-controlled magnetic valve type flexible inductor, transformer and LLC resonant converter

Abstract

A current control type magnetic valve flexible inductor is composed of an "EE" shaped core, two direct current control coils and an alternating current coil; two magnetic valves are formed on two side columns of the "EE" shaped core, and an air gap is formed on the middle column of the "EE" shaped core; the two direct current control coils are wound on the two side columns of the "EE" shaped core respectively, and the alternating current coil is wound on the middle column of the "EE" shaped core; the two direct current control coils are connected in series and pass through a direct current control current; the size of the direct current control current is adjusted to change the magnetic saturation degree of the two magnetic valves, so that the inductance of the alternating current coil is adjusted in a super wide range. The flexible inductor has the advantages of less direct current control coil turns, small current, large alternating current coil inductance adjustment range and the like, and is used in an LLC resonant converter to realize super wide input and output voltage range adjustment and super wide load range adjustment of the converter, and current sharing control of a multi-path parallel converter.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of power electronic converters, in particular to a current-controlled magnetic valve flexible resonant inductor and a flexible resonant transformer used in a power electronic LLC resonant converter. BACKGROUND

[0002] In recent years, switching power supplies for various electrical equipment are developing towards low voltage, large current, small volume, light weight, high efficiency, thinness and integration, including voltage regulation modules for providing precise power supply for high-precision, high-speed microprocessors such as central processing units (CPUs) and digital signal processors (DSPs), and switching power supplies widely used in the fields of large data centers, electric vehicles, hybrid vehicles, uninterruptible power supplies, power quality regulating power supplies, aviation power supplies, new energy power generation and superconducting energy storage in recent years. These switching power supplies adopt the topology structure of resonant converters, especially LLC resonant converters and LCC resonant converters, so that the resonant converters can realize zero-voltage turn-on (ZVS) of the primary side switch tube of the transformer and zero-current turn-off (ZCS) of the secondary side switch tube, and have the advantages of low loss, low switching stress, high efficiency and high power density. Therefore, LLC resonant converters and LCC resonant converters and other resonant converters have been widely used in the above-mentioned fields.

[0003] The traditional LLC resonant converter faces two main problems: first, the LLC resonant converter adopts variable frequency control for output voltage and load regulation. However, when the input voltage range, output voltage range and load variation range are wide, the switching frequency variation range of the LLC resonant converter also becomes wide, which makes it difficult to optimize the design of the resonant inductor and the resonant transformer; second, in order to expand the capacity, the LLC resonant converter often needs to operate in multiple parallel modes. However, due to the tolerances of the resonant elements of each parallel phase (inductance tolerance ±5%, capacitance tolerance ±5%), the resonant currents and rectified output currents of each parallel phase are not balanced, and in severe cases, the circuit can be damaged.

[0004] In order to solve these two problems, people have researched variable inductors and variable transformers. However, the cross-sectional area of the core side column of the traditional variable inductor and the variable transformer remains unchanged, and a large number of direct current ampere turns are required to enter the transition zone of the magnetic material to adjust the resonant inductance value, resulting in a large number of turns of the direct current control winding and a large current. The variable inductor and the variable transformer have the problems of large volume, high cost, large loss and narrow inductance adjustment range. SUMMARY

[0005] The purpose of the present application is to overcome the above technical deficiencies, provide a current control type magnetic valve flexible inductor and flexible transformer, for LLC resonant converter and LCC resonant converter and other resonant converters, by changing the size of the direct current control current of the current control type magnetic valve flexible inductor and flexible transformer, the inductance value of the flexible inductor and the excitation inductance value of the flexible resonant transformer are adjusted in a super wide range, so as to realize the super wide input and output voltage range and the super wide load change range of the LLC resonant converter, and the current sharing control of the multi-path parallel LLC resonant converter.

[0006] The technical scheme adopted by the present application to solve its technical problems is:

[0007] A current control type magnetic valve flexible inductor is composed of two "E" shaped cores, two direct current control coils and an alternating current coil; the end section area of the two side columns of the "E" shaped core is smaller than that of the other part of the side column, the length of the end of the two side columns is equal, and the middle column of the two "E" shaped cores is shorter than the side column; all the magnetic columns of the two "E" shaped cores are placed opposite to each other, forming an "EE" shaped core, and the two magnetic valves of the "EE" core are formed by the end sections of the four side columns of the "EE" shaped core which are placed opposite to each other; since the middle column of the "EE" core is shorter than the side column, an air gap is formed between the two middle columns of the "EE" shaped core; the two direct current control coils are wound around the four side columns of the "EE" shaped core which are placed opposite to each other, and the alternating current coil is wound around the middle column of the "EE" shaped core; the two direct current control coils are connected in series and a direct current control voltage is applied to generate a direct current control current, which generates a direct current magnetic flux in the four side columns and the two magnetic yokes of the "EE" shaped core; an alternating current is passed through the alternating current coil to generate an alternating current magnetic flux in the middle column of the "EE" shaped core, which is divided into two parts and passes through the four side columns of the "EE" shaped core which are placed opposite to each other; the size of the direct current control voltage is adjusted to change the size of the direct current control current, control the magnetic saturation degree of the two magnetic valves, and thus realize the super wide range adjustment of the inductance of the alternating current coil.

[0008] The current control type magnetic valve flexible inductor provided by the present application has the advantages of fewer turns of the direct current control coil, smaller direct current control current, larger inductance adjustment range of the alternating current coil, etc., and can be used in various types of resonant converters such as LLC resonant converter and LCC resonant converter, to realize the super wide input and output voltage range and the super wide load change range adjustment of the resonant converter, and the current sharing control of the multi-path parallel resonant converter.

[0009] The embodiments will be described in detail below with reference to the accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS

[0010] Figure 1 is a structure front view of a rectangular magnetic valve type "EE" core.

[0011] Figure 2 is Figure 1 is a structure front view of a current control type rectangular magnetic valve type flexible inductor of

[0012] Figure 3 is Figure 2 is a structure front view of a current control type rectangular magnetic valve type flexible transformer of

[0013] Figure 4 is Figure 1 is a structure front view of a two-stage rectangular magnetic valve type "EE" core of

[0014] Figure 5 is Figure 1 is a structure front view of a trapezoidal magnetic valve type "EE" core of

[0015] Figure 6 is Figure 1 is a structure front view of a trapezoidal+rectangular magnetic valve type "EE" core of

[0016] Figure 7 is Figure 1 is a structure front view of a quarter circular arc+rectangular magnetic valve type "EE" core of

[0017] Figure 8 is Figure 1 is a structure front view of a rectangular magnetic valve type "EE" core of

[0018] Figure 9 is Figure 8 and Figure 2 is a structure front view of a current control type rectangular magnetic valve type flexible inductor of

[0019] Figure 10 is Figure 9 is a structure front view of a current control type rectangular magnetic valve type flexible transformer of

[0020] Figure 11 is Figure 2 is a circuit topology diagram of an LLC resonant converter based on a current control type magnetic valve type flexible inductor of

[0021] Figure 12 is Figure 3 is a circuit topology diagram of an LLC resonant converter based on a current control type magnetic valve type flexible transformer of

[0022] Fig. 1-1 "E" shaped core; 2-outer side magnetic column of "E" shaped core; 3-middle column of "E" shaped core; 4-magnetic yoke of "E" shaped core 1; 5-air gap between middle columns 3 of two "E" shaped cores 1, 2-1-rectangular small cross-sectional area end of outer side magnetic column 2 of "E" shaped core 1; A-cross-sectional area of outer side magnetic column 2 of "E" shaped core 1; A1-cross-sectional area of rectangular end 2-1 of outer side magnetic column 2 of "E" shaped core 1, A1 is smaller than A; d-length of end 2-1; 6-"EE" shaped core composed of two "E" shaped cores 1, side column ends 2-1 of two "E" shaped cores 1 are placed face to face oppositely, forming a rectangular magnetic valve with length of 2d and cross-sectional area of A1; N dc1 , N dc2 -two DC control coils wound on four outer side magnetic columns 2 of "EE" shaped core respectively, two by two oppositely placed; N ac1 , N ac2 -two AC coils wound on two oppositely placed middle columns 3 of "EE" shaped core; I dc -DC control current passing through two series connected DC control coils N dc1 , N dc2 ; Φ dc -DC magnetic flux generated by DC control current I dc in four outer side magnetic columns 2 of "EE" shaped core, two by two oppositely placed; i ac1 -AC current passing through AC coil N ac1 ; Φ ac -AC magnetic flux generated by AC current i ac1 in middle column 3 of "EE" shaped core; Φ ac1 , Φ ac2 -AC magnetic flux Φ ac is divided into two parts in four outer side magnetic columns 2 of "EE" shaped core, two by two oppositely placed; L ac1 , L ac1 -inductance of AC coil N ac1 , N ac2 ; i ac2 -AC current induced in AC coil N ac by AC magnetic flux Φ ac2 ; V in , V o -DC input and output voltage of LLC resonant converter; Q1, Q2, Q3, Q4-power electronic switching devices on primary side of LLC resonant converter; L r -resonant inductance of LLC resonant converter; N r -winding of resonant inductance L r ; C r -resonant capacitance of LLC resonant converter; T r- resonant transformer of LLC resonant converter; N p 、 s - primary and secondary winding of resonant transformer T r ; L m - magnetizing inductance of primary winding N p ; D - secondary side rectifier circuit of LLC resonant converter; C o - DC output filter capacitor of LLC resonant converter; R L - load resistance of LLC resonant converter; V ref - given DC voltage of LLC resonant converter control system; ΔV - deviation of given DC voltage V ref of LLC resonant converter control system from output DC voltage V o ; PI - proportional-integral regulator. DETAILED DESCRIPTION

[0023] The specific embodiments of the present application will be further described in conjunction with the drawings and examples. The following examples are used to illustrate the present application, but are not used to limit the scope of the present application. In order to fully understand the present application, many specific details are mentioned in the following detailed description. However, it should be understood by those skilled in the art that the present application can be implemented without these specific details.

[0024] Example 1

[0025] Referring to the drawings and examples Figure 1 、 2 , a current control type magnetic valve flexible inductor is composed of two "E" shaped cores 1, two direct current control coils N dc1 , N dc2 and an alternating current coil N ac1 ; the cross-sectional area A1 of the end portion 2-1 of the two side columns 2 of the "E" shaped core 1 is smaller than the cross-sectional area A of other parts of the side column 2, the length of the end portion 2-1 of the side column 2 is d, and the middle column 3 of the two "E" shaped cores 1 is shorter than the side column 2; the two "E" shaped cores 2 are placed face to face respectively to form an "EE" shaped core, and two rectangular magnetic valves 6 with a length of 2d and a cross-sectional area of A1 are formed by the end portions 2-1 of the four side columns 2 of the "EE" shaped core which are placed face to face respectively; since the middle column 3 of the "EE" shaped core is shorter than the side column 2, an air gap 5 is formed between the two middle columns 3 of the "EE" shaped core; the two direct current control coils N dc1 , N dc2 are wound around the four side columns 2 of the "EE" shaped core which are placed face to face respectively, and the alternating current coil N ac1 is wound around the middle column 3 of the "EE" shaped core; the two direct current control coils N dc1 , Ndc2 series, and a DC control voltage V is applied dc to generate a DC control current I dc , in the four side columns 2 and two yokes 4 of the "EE" shaped core, a DC magnetic flux Φ is generated dc ; in the AC coil N ac1 , an AC current i ac1 is passed, in the center column of the "EE" shaped core, an AC magnetic flux Φ is generated ac , the AC magnetic flux Φ ac is divided into two: Φ ac1 and Φ ac2 , respectively passing through the four side columns 2 of the "EE" shaped core, which are placed opposite to each other in pairs; adjusting the size of the DC control voltage V dc to change the size of the DC control current I dc , the magnetic saturation degree of the two rectangular magnetic valves 6 can be controlled, so as to realize the super-wide range adjustment of the inductance L ac1 of the AC coil N ac1 .

[0026] Example two:

[0027] Referring to the accompanying Figure 3 , a current control type magnetic valve type flexible transformer, the AC coil N ac1 in example 1 is taken as the primary winding of the flexible transformer; an AC coil N ac2 is added to the center column 3 of the "EE" shaped core in example 1, which is taken as the secondary winding of the flexible transformer; an AC voltage is applied to the input end of the primary winding N ac1 , to generate a primary AC current i ac1 , in the center column 3 of the "EE" core, an AC magnetic flux Φ is generated ac1 , the AC magnetic flux Φ ac1 generates an induced electromotive force on the secondary winding N ac2 , to output a secondary AC current i ac2 ; the AC magnetic flux Φ ac1 is divided into two: Φ ac1 , Φ ac2 , respectively passing through the four side columns 2 of the "EE" shaped core, which are placed opposite to each other in pairs; adjusting the size of the DC control voltage V dc to change the size of the DC control current I dc , the magnetic saturation degree of the two rectangular magnetic valves 6 can be controlled, so as to realize the super-wide range adjustment of the excitation inductance L ac1 of the primary winding N ac1 of the flexible transformer.

[0028] Example three:

[0029] Referring to the drawings Figure 4 A current-controlled magnetic valve flexible inductor, the rectangular magnetic valve 6 described in Embodiment 1 is changed to a two-stage rectangular magnetic valve, wherein the sectional area A2 of the second-stage magnetic valve 6-2 is smaller than the sectional area Al of the first-stage magnetic valve 6-1; the direct-current control coil, the alternating-current coil of the current-controlled magnetic valve flexible inductor described in this embodiment are the same as those of the current-controlled magnetic valve flexible inductor described in Embodiment 1. Figure 2 The direct-current control coil, the alternating-current coil are the same. In addition, the current-controlled magnetic valve flexible inductor described in this embodiment can also be changed to a current-controlled magnetic valve flexible transformer according to Embodiment 2.

[0030] Embodiment Four

[0031] Referring to the drawings Figure 5 A current-controlled magnetic valve flexible inductor, the rectangular magnetic valve 6 described in Embodiment 1 is changed to a double trapezoidal magnetic valve 6-3; the alternating-current coil, the direct-current coil of the current-controlled magnetic valve flexible inductor described in this embodiment are the same as those of the current-controlled magnetic valve flexible inductor described in Embodiment 1. Figure 2 The alternating-current coil, the direct-current coil are the same. In addition, the current-controlled magnetic valve flexible inductor described in this embodiment can also be changed to a current-controlled magnetic valve flexible transformer according to Embodiment 2.

[0032] Embodiment Five

[0033] Referring to the drawings Figure 6 A current-controlled magnetic valve flexible inductor, the double trapezoidal magnetic valve 6-3 described in Embodiment 4 is changed to a double trapezoidal+rectangular magnetic valve 6-4; the alternating-current coil, the direct-current coil of the current-controlled magnetic valve flexible inductor described in this embodiment are the same as those of the current-controlled magnetic valve flexible inductor described in Embodiment 1. Figure 2 The alternating-current coil, the direct-current coil are the same. In addition, the current-controlled magnetic valve flexible inductor described in this embodiment can also be changed to a current-controlled magnetic valve flexible transformer according to Embodiment 2.

[0034] Embodiment Six

[0035] Referring to the drawings Figure 7 A current-controlled magnetic valve flexible inductor, the rectangular magnetic valve 6 described in Embodiment 1 is changed to a double quarter-circle+rectangular magnetic valve 6-5, the radius of the quarter circle is R, the width of the rectangle is W, and the height of the rectangle is 2d; the alternating-current coil, the direct-current coil of the current-controlled magnetic valve flexible inductor described in this embodiment are the same as those of the current-controlled magnetic valve flexible inductor described in Embodiment 1. Figure 2 The alternating-current coil, the direct-current coil are the same. In addition, the current-controlled magnetic valve flexible inductor described in this embodiment can also be changed to a current-controlled magnetic valve flexible transformer according to Embodiment 2.

[0036] Embodiment Seven

[0037] Referring to the drawings Figure 8 , 9A current-controlled magnetic valve type flexible inductor, in which the positions of the two side columns 2 with magnetic valves 6 and the two middle columns 3 with magnetic valves 6 of the "EE" shaped core described in Embodiment 1 are interchanged. In addition, the positions of the two side columns 2 with magnetic valves 6 and the two middle columns 3 with magnetic valves 6 of the "EE" shaped core described in Embodiments 3 to 6 can also be interchanged.

[0038] Embodiment Eight:

[0039] Reference is made to the accompanying drawings that form a part of this disclosure Figure 10 A current-controlled magnetic valve type flexible transformer, in which the positions of the two side columns 2 with magnetic valves 6 and the two middle columns 3 with magnetic valves 6 of the "EE" shaped core described in Embodiment 2 are interchanged. In addition, the positions of the two side columns 2 with magnetic valves 6 and the two middle columns 3 with magnetic valves 6 of the "EE" shaped core described in Embodiments 3 to 6 can also be interchanged.

[0040] Embodiment Nine:

[0041] Reference is made to the accompanying drawings that form a part of this disclosure Figure 11 An LLC resonant converter based on a current-controlled magnetic valve type flexible inductor, in which the current-controlled magnetic valve type flexible inductor described in Embodiment 1 is used as the resonant inductor L r of the LLC resonant converter. The deviation ΔV between the given DC voltage V ref and the output DC voltage V o is adjusted by a PI (proportional integral) controller to obtain a DC control voltage V con , which is input to a voltage control current source to obtain a DC control current I dc , which is input to the DC control coil N dc1 and N dc2 of the current-controlled magnetic valve type flexible inductor to achieve the super-wide range adjustment of the resonant inductor L r of the LLC resonant converter, thereby achieving the super-wide range adjustment of the input voltage V in , the output voltage V o and the load resistance R L of the LLC resonant converter, as well as the current sharing control of the primary side resonant current and the secondary side diode rectification current of the transformer of the multi-path parallel LLC resonant converter.

[0042] Embodiment Ten:

[0043] Reference is made to the accompanying drawings that form a part of this disclosure Figure 12 An LLC resonant converter based on a current-controlled magnetic valve type flexible transformer, in which the current-controlled magnetic valve type flexible transformer described in Embodiment 2 is used as the resonant transformer T rThe given DC voltage V in the control system of the LLC resonant converter ref With output DC voltage V o The deviation ΔV is adjusted by a PI (proportional-integral) regulator to obtain the DC control voltage V. con After passing through a voltage-controlled current source, a DC control current I is obtained. dc The DC control coil N of the current-controlled magnetic valve type flexible transformer is fed into the transformer. dc1 and N dc2 To realize the resonant transformer T of the LLC resonant converter r excitation inductance L m The ultra-wide range of adjustment enables the input voltage V of the LLC resonant converter to be adjusted. in Output voltage V o and load resistance R L The adjustment range is extremely wide.

[0044] Finally, it should be noted that the above-described embodiments are merely preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. This specification uses the above embodiments to describe the principles and implementation methods of the present invention, only to help understand the method and core ideas of the present invention; at the same time, those skilled in the art will understand that, based on the ideas of the present invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of the present invention, and any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention are included within the scope of protection of the present invention.

Claims

1. A current-controlled magnetic valve soft inductor, which is composed of two "E" shaped cores, two direct current control coils and one alternating current coil, characterized in that: The two side column end sections of the "E" shaped core have smaller cross-sectional areas than the other sections of the side columns, the lengths of the two side column end sections are equal, and the middle column of the two "E" shaped cores is shorter than the side columns; the four side column end sections of the two "E" shaped cores are placed face to face to form an "EE" shaped core, and the two rectangular magnetic valves of the "EE" shaped core are formed by the four side column end sections of the "EE" shaped core; the middle column of the "EE" shaped core is shorter than the side columns, and an air gap is formed between the two middle columns of the "EE" shaped core; the two DC control coils are wound around the four side columns of the "EE" shaped core, and the AC coil is wound around the two middle columns of the "EE" shaped core; the two DC control coils are connected in series, and a DC control voltage is applied to generate a DC control current, which generates a DC magnetic flux in the four side columns and the two magnetic yokes of the "EE" shaped core; an AC current is applied to the AC coil to generate an AC magnetic flux in the middle columns of the "EE" shaped core, and the AC magnetic flux is divided into two parts and passes through the four side columns of the "EE" shaped core; the size of the DC control current is changed by adjusting the size of the DC control voltage, the magnetic saturation of the two rectangular magnetic valves is controlled, and the inductance of the AC coil is adjusted in a super wide range.

2. A current controlled magnetic valve soft inductor according to claim 1, characterized in that: An AC coil is added to the middle column of the "EE" shaped core to form a current-controlled magnetic valve type flexible transformer, the AC coil of the flexible inductor in claim 1 is used as the primary winding of the flexible transformer, and the added AC coil is used as the secondary winding of the flexible transformer; a primary AC voltage is applied to the input end of the primary winding to generate a primary AC current, which generates a primary AC magnetic flux in the middle column of the "EE" shaped core and generates an induced potential on the secondary winding to output a secondary AC current; the primary AC magnetic flux is divided into two parts and passes through the four side columns of the "EE" shaped core; the size of the DC control current is changed by adjusting the size of the DC control voltage, the magnetic saturation of the two magnetic valves is controlled, and the excitation inductance of the primary winding of the flexible transformer is adjusted in a super wide range.

3. A current controlled magnetic valve soft inductor according to claim 1, characterized in that: The rectangular magnetic valve is a two-stage magnetic valve, and the cross-sectional area of the middle part of the rectangular magnetic valve is reduced; the part where the cross-sectional area is not reduced is referred to as a first-stage rectangular magnetic valve, and the part where the cross-sectional area is reduced is referred to as a second-stage rectangular magnetic valve; the DC control coil and the AC coil of the current-controlled magnetic valve type flexible inductor are the same as the DC control coil and the AC coil in claim 1.

4. A current-fed magnetic valve soft inductor according to claim 2, characterized in that: The cross-sectional areas of the side column end sections of the two "E" shaped cores are gradually reduced towards the end tips to form trapezoidal magnetic valves with two trapezoidal shapes and two short sides facing each other; the DC control coil and the AC coil of the flexible inductor are the same as the DC control coil and the AC coil in claim 1.

5. A current-fed magnetic valve soft inductor according to claim 4, characterized in that: The side column end section of the "E" shaped iron core is gradually reduced in cross-sectional area towards the end tip, then remains unchanged, forming a magnetic valve with a trapezoid+rectangle in the front view; the DC control coil and AC coil of the flexible inductor are the same as those in claim 1.

6. A current controlled magnetic valve soft inductor according to claim 2, characterized in that: The side column end section of the "E" shaped iron core is gradually reduced in cross-sectional area towards the end tip, then remains unchanged, forming a magnetic valve with a trapezoid+rectangle in the front view; the DC control coil and AC coil of the flexible inductor are the same as those in claim 1.

7. The current-controlled magnetic valve soft inductor of claim 1, wherein: The positions of the two side columns with magnetic valves and the two middle columns of the "EE" shaped iron core are interchanged.

8. A current controlled magnetic valve soft inductor according to claim 2, characterized in that: The positions of the two side columns with magnetic valves and the two middle columns of the "EE" shaped iron core are interchanged.

9. The current-controlled magnetic valve soft inductor of claim 1, wherein: The current-controlled magnetic valve type flexible inductor is used in an LLC resonant converter as the resonant inductor of the LLC resonant converter; the deviation between the given DC voltage and the detected output DC voltage in the control system of the LLC resonant converter is adjusted by proportional integral to obtain a DC control voltage, which is passed through a voltage-controlled current source to obtain a DC control current, which is input into the two DC control coils of the current-controlled magnetic valve type flexible inductor, realizing the super-wide range adjustment of the resonant inductance of the LLC resonant converter, thereby realizing the super-wide range adjustment of the input voltage, output voltage and load of the LLC resonant converter, and the current sharing control of the primary side resonant current and the secondary side rectified current of the transformer of the multi-path parallel LLC resonant converter.

10. The current-controlled magnetic valve soft inductor according to claim 2, characterized in that: The current-controlled magnetic valve type flexible transformer in claim 2 is used in an LLC resonant converter as the resonant transformer of the LLC resonant converter; the deviation between the given DC voltage and the detected output DC voltage in the control system of the LLC resonant converter is adjusted by proportional integral to obtain a DC control voltage, which is passed through a voltage-controlled current source to obtain a DC control current, which is input into the DC control coil of the resonant transformer, realizing the super-wide range adjustment of the primary side excitation inductance value of the resonant transformer, thereby realizing the super-wide range adjustment of the input voltage, output voltage and load of the LLC resonant converter.

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