Astronavigation secondary power supply LLC magnetic integration structure

Abstract

The invention provides an aerospace secondary power supply LLC magnetic integration structure, and aims to provide a lightweight integration scheme for an aerospace secondary power supply. The primary windings are respectively wound on magnetic columns in the middle and on two sides of the magnetic core so as to generate ideal leakage inductance to replace resonant inductance. A relation exists between leakage inductance and the number of turns Tp1 and Tp2 of the magnetic columns on the two sides, and under the condition that the total equivalent number of turns Tp of the primary side is kept unchanged, when Tp1 and Tp2 change, excitation inductance is almost kept unchanged. And the cost is reduced while the power density of the converter is improved. The transformer comprises a pair of oppositely-arranged three-magnetic-column magnetic cores and a primary winding complex variable winding, and part of the primary winding is wound on magnetic columns on the two sides respectively. The secondary sides are all wound on the middle column; the primary side is connected to the primary side circuit, and the secondary side is connected to the output rectification circuit.

Description

Technical Field

[0001] This invention belongs to the field of aerospace secondary power supply technology, and specifically relates to an LLC magnetic integrated structure for aerospace secondary power supplies. Background Technology

[0002] With the continuous development of power electronics technology, the requirements for high frequency, high power density, and integration of DC / DC converters are constantly increasing. LLC resonant converters have attracted much attention in the field of high-frequency power conversion due to their ability to achieve soft switching and adapt to higher frequencies. However, LLC resonant converters contain a large number of magnetic components. According to statistics, magnetic components such as transformers and inductors account for 30% to 40% of the weight of the converter and about 20% to 30% of its volume. Therefore, magnetic components have become the main factor limiting the improvement of the converter's power density. For aerospace secondary power supplies, the power supply design is very sensitive to weight, so the increased size and weight of the converter due to too many magnetic components is unacceptable. Since the resonant network of an LLC resonant converter requires a resonant inductor and a transformer, if magnetic integration technology is applied to integrate the two into a single magnetic core, using the leakage inductance of the transformer as the resonant inductor, the power density of the transformer can be further improved.

[0003] However, integrating multiple magnetic components onto a single magnetic core can lead to mutual coupling between these components, making it difficult to adjust the values ​​of individual devices and consequently complicating circuit parameter design. Alternatively, using two magnetic cores to achieve multiple magnetic circuits can provide a certain degree of precise adjustment of the magnetic component values, but the reduction in size and weight is minimal. Summary of the Invention

[0004] This invention solves the technical problem that in traditional planar transformers, the primary winding is wound on the middle magnetic post of the core, and the secondary winding is also wound on the middle magnetic post, resulting in low leakage inductance, which is not conducive to considering the leakage inductance as a resonant inductance.

[0005] The technical solution of the present invention is as follows:

[0006] This invention provides an LLC magnetic integrated structure for aerospace secondary power supplies, comprising: a magnetic core, a primary winding, and a secondary winding;

[0007] The magnetic core includes a first magnetic column, a second magnetic column, and a third magnetic column arranged sequentially in the transverse direction;

[0008] The cross-sectional area of ​​the first magnetic column is equal to the cross-sectional area of ​​the third magnetic column, and the sum of the cross-sectional areas of the first magnetic column and the third magnetic column is equal to the cross-sectional area of ​​the second magnetic column.

[0009] The primary winding is wound on the first magnetic post, the second magnetic post and the third magnetic post respectively, and the secondary winding is wound only on the second magnetic post;

[0010] The primary winding is connected to the primary circuit of the LLC resonant converter, and the secondary winding is connected to the secondary rectifier circuit of the LLC resonant converter. The primary winding and the secondary winding are arranged alternately on the second magnetic column.

[0011] Furthermore, the primary winding generates leakage flux at the first and third magnetic pillars to form a leakage inductance that replaces the resonant inductance of the LLC resonant converter. The primary winding and the secondary winding cooperate to form a transformer structure, and the magnetic core cooperates with the primary winding to form a magnetizing inductance.

[0012] Furthermore, the leakage inductance is adjusted by modifying the winding distribution on the first and third magnetic pillars; the excitation inductance is changed by altering the air gap width, thereby achieving decoupled adjustment of the leakage inductance and the excitation inductance.

[0013] Furthermore, the magnetic core used can be vertical or planar; the cross-sectional shape of the magnetic column is not limited.

[0014] Furthermore, the primary winding is a planar winding or a wire winding; the secondary winding is a planar winding or a wire winding.

[0015] Furthermore, the sum of the cross-sectional areas of the first and third magnetic pillars is equal to the cross-sectional area of ​​the second magnetic pillar.

[0016] Furthermore, air gaps are provided on the first magnetic column, the second magnetic column, and the third magnetic column, and the air gap magnetic reluctance of the first magnetic column is denoted as R. g1 The air gap magnetoresistance of the second magnetic column is denoted as R. g2 The air gap magnetoresistance of the third magnetic column is denoted as R. g3 And satisfy:

[0017]

[0018] Among them, R air Let S1 be the area of ​​the first magnetic cylinder, S2 be the area of ​​the second magnetic cylinder, S3 be the area of ​​the third magnetic cylinder, and R be the air reluctance. Fe This refers to the magnetic reluctance of the magnetic core itself.

[0019] Furthermore, the number of turns of the primary winding wound on the first magnetic post is T. p1 The number of turns of the primary winding wound on the second magnetic post is T. p2 The number of turns of the primary winding wound on the third magnetic post is T. p3 ;

[0020] The total equivalent number of turns T on the primary side p satisfy:

[0021]

[0022] The leakage inductance L k The calculation formula is:

[0023]

[0024] Furthermore, the sensing L m The calculation formula is:

[0025]

[0026] Among them, R g1 / / R g3 R represents g1 With R g3 in parallel.

[0027] Furthermore, the first magnetic post and the third magnetic post are symmetrically distributed about the central axis of the second magnetic post; the wire specifications of the primary winding wound on the first magnetic post are the same as those of the wire specifications wound on the third magnetic post; the winding density of the primary winding on the first magnetic post is the same as that on the third magnetic post.

[0028] The beneficial effect of this invention is that the leakage inductance can be adjusted by the number of turns of the windings of the two magnetic pillars, while the magnetizing inductance remains unchanged; and when the air gap is changed, the magnetizing inductance decreases, while the leakage inductance remains almost unchanged. This achieves a decoupled design between the leakage inductance and the magnetizing inductance. Attached Figure Description

[0029] Figure 1 (a) is a schematic diagram of a circular cross-sectional area integrated magnetic core according to the present invention;

[0030] Figure 1 (b) is a schematic diagram of a circular cross-sectional area integrated magnetic core winding according to the present invention;

[0031] Figure 2 This is a schematic diagram of the connection of the integrated magnetic component of the present invention in a half-bridge LLC circuit;

[0032] Figure 3 This is the primary magnetic circuit diagram of the integrated magnetic component of the present invention;

[0033] Figure 4 This is the secondary magnetic circuit diagram of the integrated magnetic component of the present invention;

[0034] Figure 5 This is the topology diagram of the discrete magnetic half-bridge LLC circuit of the present invention;

[0035] Figure 6 This is a schematic diagram of the integrated magnetic component structure of the EE-type magnetic core in an embodiment of the present invention. Detailed Implementation

[0036] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings. It should be noted that the drawings are all in a very simplified form and use non-precise ratios, and are only used to facilitate and clarify the explanation of the embodiments of the present invention.

[0037] This invention provides an LLC magnetic integrated structure for aerospace secondary power supplies, wherein, in the magnetic core, as shown... Figure 1 (a) The primary winding is wound on three magnetic pillars. The areas of the first, second, and third magnetic pillars are S1, S2, and S3, respectively, and the air gap reluctances of the first, second, and third magnetic pillars are R1, S2, and S3, respectively. g1 R g2 R g3 ;like Figure 1 (b) The primary windings of the first, second, and third magnetic pillars are T, respectively. p1 T p2 T p3 Leakage inductance is generated by increasing the leakage flux in the air, and the leakage inductance can be adjusted by changing the winding distribution on the three magnetic pillars. The secondary winding T s1 T s2 The core and the magnetic pillars are wound alternately and in parallel on the second magnetic pillar. The cross-sectional area of ​​the magnetic core and the magnetic pillar is circular.

[0038] Figure 2 This is a schematic diagram showing the connection of the integrated magnetic component 5 in the half-bridge LLC circuit of the present invention. The V in the DC power supply 1... in The positive terminal is connected to the drain of switching transistor Q1 and the source of switching transistor Q2, achieving inversion through half-bridge inverter 2. The resonant capacitor C in resonant cavity 3... r Connected between the source of the half-bridge switching transistor Q1 and the drain of Q2, the integrated magnetic component is connected after the resonant capacitor to achieve voltage transformation. The secondary winding output is connected to the anode of diodes D1 and D2 in the rectifier network 4 for rectification to achieve output.

[0039] For the primary magnetic circuit, such as Figure 3 In the diagram, magnetic circuit I and magnetic circuit II are the main magnetic fluxes, and the magnetic reluctance within them includes the magnetic reluctance R of the magnetic core itself. Fe It also includes the air gap magnetoresistance R passing through the air gap. g1 R g2 R g3 Magnetic circuits III and IV are the leakage fluxes on both sides, which also contain the magnetic core reluctance R. Fe and air magnetic resistance R air .

[0040] Magnetic column air gap reluctance R g Air magnetic reluctance R in the leakage magnetic circuit air and magnetic core reluctance R Fe Relationship

[0041] Secondary magnetic circuit such as Figure 4At this time, magnetic circuit I and magnetic circuit III, and magnetic circuit II and magnetic circuit IV are connected in parallel.

[0042] By arranging the primary and secondary windings above and below the primary winding respectively, an alternating arrangement can be achieved, which can reduce some leakage inductance caused by residual magnetic flux.

[0043] Since the sum of the cross-sectional areas of the two magnetic pillars is equal to that of the middle magnetic pillar, the equivalent primary winding T can be derived. p and three Ts p1 T p2 T p3 The relationship is because Ignore R Fe Then the expression for the magnetizing inductance can be obtained as follows: In the formula, if the magnetic reluctance of the air gap of the magnetic column and T P If L remains unchanged, then m Unchanged. If the air gap increases, L m It will decrease.

[0044] Regarding leakage inductance, since in the magnetic circuit Ignore R Fe The leakage inductance formula can be obtained as follows: Therefore, if T1 and T3 increase, L k It will increase. Meanwhile, L k With T1 2 Or T3 2 The relationship is linear. Because R... air >>R g1 ,R air >>R g3 The change in the air gap of the magnetic column alters R g The impact on leakage is very small.

[0045] Figure 5 This is the original circuit topology diagram of the half-bridge LLC resonant converter before integration. In this invention, leakage inductance is integrated to replace resonant inductance and transformer.

[0046] Figure 6 This is an integrated magnetic core with a rectangular cross-sectional area. The areas of the first, second, and third magnetic pillars are S1, S2, and S3, respectively, where S2 = S1 + S3 and S1 = S3. The winding on the three magnetic pillars is T. p1 =2,T p2 =4, T p3 =2, at this time T p =5 turns, the magnetizing inductance can be simplified to Leakage inductance can be simplified to At this point, change the winding T of the two magnetic pillars. p1 T p2 At the same time, T pThe leakage inductance can be adjusted without affecting the magnetizing inductance; and because R... air >>R g1 ≈2R g2 ≈R g3 >>R Fe This can be achieved by modifying R. g1 R g2 R g3 The value of the magnetizing inductance is adjusted by adjusting the value of the magnetizing inductance, while having minimal impact on the leakage inductance. This achieves decoupling between the magnetizing inductance and the leakage inductance.

[0047] The contents not described in detail in this specification are prior art known to those skilled in the art. It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within the present invention.

Claims

1. A magnetically integrated LLC structure for aerospace secondary power supplies, characterized in that, include: Magnetic core, primary winding, and secondary winding; The magnetic core includes a first magnetic column, a second magnetic column, and a third magnetic column arranged sequentially in the transverse direction; The cross-sectional area of ​​the first magnetic column is equal to the cross-sectional area of ​​the third magnetic column, and the sum of the cross-sectional areas of the first magnetic column and the third magnetic column is equal to the cross-sectional area of ​​the second magnetic column. The primary winding is wound on the first magnetic post, the second magnetic post and the third magnetic post respectively, and the secondary winding is wound only on the second magnetic post; The primary winding is connected to the primary circuit of the LLC resonant converter, and the secondary winding is connected to the secondary rectifier circuit of the LLC resonant converter. The primary winding and the secondary winding are arranged alternately on the second magnetic column.

2. The aerospace secondary power supply LLC magnetic integrated structure as described in claim 1, characterized in that, The primary winding generates leakage flux at the first and third magnetic pillars to form a leakage inductance that replaces the resonant inductance of the LLC resonant converter. The primary winding and the secondary winding cooperate to form a transformer structure. The magnetic core and the primary winding cooperate to form a magnetizing inductance.

3. The aerospace secondary power supply LLC magnetic integrated structure as described in claim 1, characterized in that, The leakage inductance is adjusted by modifying the winding distribution on the first and third magnetic pillars; the excitation inductance is changed by altering the air gap width, thus achieving decoupled adjustment of the leakage inductance and the excitation inductance.

4. The aerospace secondary power supply LLC magnetic integrated structure as described in claim 1, characterized in that, The magnetic core used can be vertical or planar; the cross-sectional shape of the magnetic column is not limited.

5. The aerospace secondary power supply LLC magnetic integrated structure as described in claim 1, characterized in that, The primary winding is a planar winding or a wire winding; the secondary winding is a planar winding or a wire winding.

6. The aerospace secondary power supply LLC magnetic integrated structure as described in claim 1, characterized in that, The sum of the cross-sectional areas of the first and third magnetic pillars is equal to the cross-sectional area of ​​the second magnetic pillar.

7. The aerospace secondary power supply LLC magnetic integrated structure as described in claim 1, characterized in that, Air gaps are provided on the first magnetic column, the second magnetic column, and the third magnetic column. The air gap reluctance of the first magnetic column is denoted as R. g1 The air gap reluctance of the second magnetic column is denoted as R. g2 The air gap reluctance of the third magnetic column is denoted as R. g3 And satisfy: Among them, R air Let S1 be the area of ​​the first magnetic cylinder, S2 be the area of ​​the second magnetic cylinder, S3 be the area of ​​the third magnetic cylinder, and R be the air reluctance. Fe This refers to the magnetic reluctance of the magnetic core itself.

8. The aerospace secondary power supply LLC magnetic integrated structure as described in claim 7, characterized in that, The number of turns of the primary winding wound on the first magnetic post is T. p1 The number of turns of the primary winding wound on the second magnetic post is T. p2 The primary winding is wound on the third magnetic post with a number of turns T. p3 ; The total equivalent number of turns T on the primary side p satisfy: The leakage inductance L k The calculation formula is:

9. The aerospace secondary power supply LLC magnetic integrated structure as described in claim 8, characterized in that, The sensing L m The calculation formula is: Among them, R g1 / / R g3 R represents g1 With R g3 in parallel.

10. The aerospace secondary power supply LLC magnetic integrated structure as described in claim 1, characterized in that, The first magnetic post and the third magnetic post are symmetrically distributed about the central axis of the second magnetic post; the wire specifications of the primary winding wound on the first magnetic post are the same as those of the wire specifications wound on the third magnetic post; the winding density of the primary winding on the first magnetic post is the same as that on the third magnetic post.

Images