Voltage compensation method and device for high frequency insulating core transformer

Abstract

The invention discloses a voltage compensation method and device for a high-frequency insulating core transformer, which belongs to the field of high-frequency insulating core transformers. The method includes: S1, establishing an equivalent circuit model of a transformer and a voltage compensation unit; S2, optimizing the capacitance value of each secondary parallel capacitor in the secondary parallel capacitor compensation unit with the goal of minimizing the mean value of voltage unevenness; S3, optimizing the pseudo primary compensation unit with the goal of minimizing the mean value of voltage unevenness and maximizing the total output voltage; S4, adjusting the parameters after the optimized design of S2 and S3, judging whether the output distribution of the adjusted transformer meets the constraint conditions, if so, executing S5, otherwise, returning to S3; S5, optimizing the coil turns of the secondary winding turns compensation unit with the goal of minimizing the mean value of voltage unevenness, and preparing the voltage compensation unit according to the final optimized design result for voltage compensation. Ensure that the voltages of each secondary of the transformer are uniform and stable.

Description

Technical Field

[0001] The present invention belongs to the field of high-frequency insulating core transformers, and more specifically, relates to a voltage compensation method and device for high-frequency insulating core transformers. Background Art

[0002] As the core equipment of electron irradiation accelerator system, the performance of high-power DC high-voltage power supply directly determines the output quality of irradiation beam. Among them, high-frequency insulation core transformer type high-voltage power supply has significant advantages in power density, device volume, working efficiency and reliability, and is an important development direction of insulation core transformer type power supply system.

[0003] In recent years, the development of power electronics technology, electromagnetic material technology, and planar transformer technology has provided room for the energy density, compactness, safety and stability of high-frequency insulating core transformers. Based on this, a high-frequency insulating core transformer with a four-core structure was produced, whose magnetic circuit consists of upper and lower magnetic yokes, primary magnetic cores, segmented secondary magnetic cores and insulating layers; in addition, the secondary winding introduces planar transformer technology, and the secondary coil and its rectifier circuit are printed on the PCB circuit board. The rectifier outputs of each PCB winding are connected in series in sequence to obtain a DC high-voltage output. However, due to the existence of the insulating layer, the problem of uneven output voltage of each layer of the secondary winding caused by the leakage magnetic phenomenon is more serious, which wastes the insulation strength of the insulating layer and the withstand voltage strength of the rectifier circuit. Once a layer of coil reaches the rated voltage value, the input voltage cannot continue to increase, resulting in the total output voltage failing to reach the rated value at this time.

[0004] The parallel capacitors of each unit of the secondary coil are the mainstream solution to the problem of uneven voltage in high-frequency insulating core transformers. However, due to the multi-layer segmented structure of the high-frequency insulating core transformer, the output impedance and load adjustment rate of each layer are different. Therefore, the effect of parallel capacitor compensation under load conditions of each layer of winding is different. Under heavier load conditions, windings with different numbers of layers need to be compensated with larger parallel capacitors of different specifications. On the one hand, it is not conducive to the safety and stability of the device and the modular design of the windings; on the other hand, a single compensation scheme cannot guarantee voltage uniformity under other conditions at the same time; furthermore, it is difficult to determine the compensation parameters through experiments. Summary of the invention

[0005] In view of the defects of the prior art and the need for improvement, the present invention provides a voltage compensation method and device for a high-frequency insulating core transformer, which aims to solve the problem of uneven secondary voltages of the high-frequency insulating core transformer and ensure the safety and stability of the device.

[0006] To achieve the above-mentioned object, according to one aspect of the present invention, a voltage compensation method for a high-frequency insulating core transformer is provided, comprising: S1, establishing an equivalent circuit model of a high-frequency insulating core transformer and its voltage compensation unit, wherein the voltage compensation unit comprises a pseudo-primary compensation unit, a secondary shunt capacitor compensation unit and a secondary winding turns compensation unit; S2, optimizing the capacitance value of each secondary shunt capacitor in the secondary shunt capacitor compensation unit with the goal of minimizing the mean value of voltage unevenness, wherein the mean value of voltage unevenness is the weighted sum of the voltage unevenness of the transformer under no-load, half-load and full-load conditions; S3 , with the goal of minimizing the mean value of the voltage unevenness and maximizing the total output voltage, the pseudo-primary compensation unit is optimized; S4, adjusting the parameters after the optimization design of S2 and S3, and judging whether the output distribution of the adjusted transformer meets the constraint conditions, if so, executing S5, otherwise, returning to S3; S5, with the goal of minimizing the mean value of the voltage unevenness, the number of coil turns of the secondary winding turns compensation unit is optimized, and the voltage compensation unit is prepared according to the final optimization design result, so as to use the prepared voltage compensation unit to perform voltage compensation on the high-frequency insulating core transformer.

[0007] Furthermore, in S2, the capacitance values ​​of the secondary parallel capacitors are uniformly optimized and designed based on the principle that the capacitance values ​​of the secondary parallel capacitors are the same.

[0008] Furthermore, in S4, the capacitance value of each secondary parallel capacitor is independently designed as a principle, and the capacitance value of each secondary parallel capacitor is adjusted respectively.

[0009] Furthermore, the secondary coils of the high-frequency insulating core transformer are divided into multiple groups, each group of secondary coils is externally connected to a rectifier circuit, and the outputs of each rectifier circuit are connected in series to output a DC voltage; the number of coil turns obtained by the optimized design in S5 is an integer multiple of the number of secondary coil turns corresponding to each rectifier circuit.

[0010] Furthermore, the voltage unevenness average is:

[0011] ΔU s % = w 1 ×ΔU sI %+w 2 ×ΔU sII %+w 3 ×ΔU sIII %

[0012]

[0013]

[0014]

[0015] Among them, ΔU s % is the mean value of the voltage unevenness, ΔU sI %, ΔU sII %, ΔU sIII % are the voltage unevenness of the transformer under no-load, half-load and full-load conditions, w 1 is the no-load weighting factor, w 2 is the half-load weighting factor, w 3 is the full load weighting factor, U sImax , U sImin are the maximum output voltage and minimum output voltage of each secondary of the transformer under no-load conditions, U sIImax , U sIImin are the maximum output voltage and minimum output voltage of each secondary of the transformer under half-load condition, U sIIImax , U sIIImin They are respectively the maximum output voltage and minimum output voltage of each secondary of the transformer under full load conditions.

[0016] Furthermore, the total output voltage is:

[0017]

[0018] Among them, U o is the total output voltage, n c is the number of magnetic core columns of the high-frequency insulating core transformer, N is the number of segmented layers of the high-frequency insulating core transformer, and U i is the DC voltage output by the i-th level winding.

[0019] Furthermore, preparing the voltage compensation unit in S5 includes: according to the parameters of the pseudo primary compensation unit finally adjusted in S4, setting a layer of pseudo primary magnetic core at the top of the high-frequency insulating core transformer; according to the capacitance value of each secondary parallel capacitor finally adjusted in S4, connecting compensation capacitors in parallel at the front end of each secondary winding basic output unit of the high-frequency insulating core transformer; according to the number of coil turns optimized in S5, setting a compensation coil, and connecting the compensation coil in series with the secondary coil of the high-frequency insulating core transformer.

[0020] According to another aspect of the present invention, a voltage compensation device for a high-frequency insulating core transformer is provided. The voltage compensation device is designed by the voltage compensation method for a high-frequency insulating core transformer as described above.

[0021] In general, the above technical scheme conceived by the present invention can achieve the following beneficial effects: designing pseudo-primary compensation for high-frequency insulating core transformers, reducing the difficulty of voltage compensation at higher levels, and reducing the capacitance of parallel compensation capacitors at higher levels, thereby reducing the capacitive current flowing through the secondary coil. At the same time, the overall difficulty of secondary parallel capacitor compensation is reduced, and better compensation effects can be achieved with fewer parallel capacitor specifications, which is beneficial to the modular design and production of PCB windings; optimizing the design based on the equivalent circuit model improves the efficiency of voltage compensation design, and circuit simulation saves a lot of manpower, computing resources and design costs compared to finite element simulation or experimental measurement; the local optimal compensation scheme can be quickly and effectively obtained, and the voltage uniformity under various working conditions is optimized to a greater extent, thereby improving the total output voltage. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 A flow chart of a voltage compensation method for a high-frequency insulating core transformer provided by an embodiment of the present invention;

[0023] Figure 2 A schematic structural diagram of a high-frequency insulating core transformer with a four-core structure provided by an embodiment of the present invention;

[0024] Figure 3 A schematic diagram of the structure of a secondary PCB winding provided in an embodiment of the present invention;

[0025] Figure 4 An equivalent circuit model diagram based on magnetic circuit analysis provided by an embodiment of the present invention;

[0026] Figure 5 A schematic diagram of a secondary circuit provided by an embodiment of the present invention.

[0027] In all drawings, the same reference numerals are used to denote the same elements or structures, wherein:

[0028] 1 is an upper magnetic yoke, 2 is a false primary magnetic core, 3 is a false primary winding, 4 is a secondary PCB, 41 is a secondary winding, 42 is a positive output port, 43 is a negative output port, 44 is a positioning hole, 45 is a rectifier circuit, 46 is a basic output unit, 47 is a secondary parallel capacitor compensation unit, 5 is a secondary magnetic core, 6 is an insulating layer, 7 is a primary winding, 8 is a primary magnetic core, and 9 is a lower magnetic yoke. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0030] In the present invention, the terms "first", "second", etc. (if any) in the present invention and the accompanying drawings are used to distinguish similar objects but not necessarily to describe a specific order or sequence.

[0031] Figure 1 A flow chart of a voltage compensation method for a high-frequency insulating core transformer provided by an embodiment of the present invention. Figure 1 , combined with Figure 2-Figure 5 , the voltage compensation method for the high-frequency insulating core transformer in this embodiment is described in detail, and the method includes operations S1 to S5.

[0032] In this embodiment, the structure of the designed high-frequency insulating core transformer and its voltage compensation unit is as follows: Figure 2 As shown, the voltage compensation unit includes a pseudo primary compensation unit, a secondary parallel capacitance compensation unit and a secondary winding turns compensation unit, which are used to compensate the high-frequency insulating core transformer. The method in this embodiment is used to design the parameters of the voltage compensation unit.

[0033] Operation S1 : establishing an equivalent circuit model of a high-frequency insulating core transformer and a voltage compensation unit thereof, wherein the voltage compensation unit includes a pseudo primary compensation unit, a secondary shunt capacitor compensation unit and a secondary winding turns compensation unit.

[0034] The pseudo primary compensation unit is a pseudo primary magnetic core set on the top of the magnetic core, and a compensation capacitor is connected in parallel to the pseudo primary coil. The pseudo primary magnetic core size and pseudo primary coil parameters are usually consistent with the corresponding primary parameters. The capacitive current on the pseudo primary coil is consistent with the excitation current on the primary coil, which is equivalent to setting an excitation source on the top layer of the magnetic core, increasing the induced voltage of the upper layer of the secondary winding and reducing the difficulty of voltage compensation of each secondary winding.

[0035] The secondary parallel capacitor compensation unit 47 is a compensation capacitor connected in parallel at the front end of each secondary winding basic output unit. It uses the characteristic that the capacitive current of the parallel capacitor is in phase with the magnetic flux in the magnetic core to compensate for the leakage magnetic field caused by each layer of insulation layer, and further evens out the output voltage of each secondary under different working conditions.

[0036] The secondary winding turns compensation unit adjusts the size of the magnetic flux by changing the number of turns of the secondary winding, thereby changing the size of the output voltage of each layer. In view of the modular design requirements and structural characteristics of the PCB secondary winding, in order not to change the inherent design size of the insulation core transformer, the secondary winding turns compensation unit adds a compensation coil and connects the compensation coil in series with the original secondary coil to achieve the goal of adjusting the number of turns of each secondary winding.

[0037] See also Figure 2The magnetic circuit structure of the high-frequency insulating core transformer and its voltage compensation unit includes: an upper magnetic yoke 1, a lower magnetic yoke 9, a primary magnetic core 8, a pseudo primary magnetic core 2, a secondary magnetic core 5 and an insulating layer 6. The primary magnetic core, the secondary magnetic core and the pseudo primary magnetic core are stacked to form a four-core structure, wherein the number of segments of the secondary magnetic core is preferably 20, and adjacent magnetic cores are separated by an insulating layer.

[0038] The winding structure of the high-frequency insulated core transformer and its voltage compensation unit includes: the primary winding 7 and the pseudo primary winding 3 use multiple strands of Litz wire, and the number of turns is preferably 4 turns; the secondary winding 41 uses a PCB coil, and the number of turns is preferably 60 turns, wherein every 5 turns of the coil are externally connected to a rectifier circuit 45 as a basic output unit 46, such as Figure 3 That is, a single PCB winding output circuit is obtained by connecting 12 basic output units 46 and their compensation units 47 in series, as shown in FIG. Figure 5 The secondary PCB 4 includes a secondary winding 41, a positive output port 42, a negative output port 43, a positioning hole 44, a rectifier circuit 45 and a basic output unit 46. The positioning hole 44 is used for positioning and installing multiple PCB boards.

[0039] In this embodiment, for example, ANSYS Simplorer software is used to build an equivalent circuit model of a high-frequency insulating core transformer and its voltage compensation unit and perform simulation analysis. The equivalent circuit model based on magnetic circuit analysis includes the excitation inductance parameters corresponding to each core segment and insulating layer, the leakage inductance parameters between each coil, and an ideal transformer unit representing the voltage transformation ratio. The equivalent circuit model is combined with the secondary-side rectifier circuit to quickly obtain the secondary output voltage under various working conditions and compensation parameters.

[0040] See also Figure 4 , shows the method for obtaining the output voltage (U s1 ~U s20 ) and current (I s1 ~I s20 ) is the equivalent circuit model of the high-frequency insulating core transformer. Among them, N p is the number of turns of the primary winding, N s1 ~N s20 is the number of turns of each secondary winding; L mp , L ms1 ~L ms21 L is the equivalent excitation inductance of each part of the magnetic core column converted to the original side; σs1 ~L σs21 is the equivalent leakage inductance between adjacent coils converted to the primary side. The circuit parameters can be obtained through finite element simulation or experimental measurement.

[0041] The design indicators in this embodiment are, for example: the design indicators of the maximum output voltage / current are 400kV / 100mA, and the operating frequency is 35kHz. The compensation indicators in the embodiment of the present invention include the voltage unevenness average value ΔU s % and total output voltage. The average voltage unevenness is:

[0042] ΔU s % = w 1 ×ΔU sI %+w 2 ×ΔU sII %+w 3 ×ΔU sIII %

[0043]

[0044]

[0045]

[0046] Among them, ΔU s % is the mean value of voltage unevenness, ΔU sI %, ΔU sII %, ΔU sIII % are the voltage unevenness of the transformer under no-load, half-load and full-load conditions, w 1 is the no-load weighting factor, w 2 is the half-load weighting factor, w 3 is the full load weighting factor, U sImax , U sImin are the maximum output voltage and minimum output voltage of each secondary of the transformer under no-load conditions, U sIImax , U sIImin are the maximum output voltage and minimum output voltage of each secondary of the transformer under half-load condition, U sIIImax , U sIIImin They are respectively the maximum output voltage and minimum output voltage of each secondary of the transformer under full load conditions.

[0047] The total output voltage is:

[0048]

[0049] Among them, U o is the total output voltage, n c is the number of core columns of the high-frequency insulation core transformer, N is the number of segmented layers of the high-frequency insulation core transformer, U i is the DC voltage output by the i-th level winding. Figure 2 The structure shown, n c =4, N=20.

[0050] by Figure 4 Taking the high-frequency insulating core transformer shown in FIG. 1 as an example, the number of segmented layers N=20, the compensation parameters in the embodiment of the present invention include: the pseudo primary capacitor C dp , secondary shunt capacitor C s1 ~C s20 And the number of turns of the secondary winding N s1 ~N s20 .

[0051] Operation S2 optimizes the capacitance of each secondary shunt capacitor in the secondary shunt capacitor compensation unit with the goal of minimizing the voltage unevenness mean value, and the voltage unevenness mean value is the weighted sum of the voltage unevenness of the transformer under no-load, half-load, and full-load conditions.

[0052] by Figure 4 Taking the high-frequency insulation core transformer shown in FIG. 1 as an example, the number of segment layers N=20, in operation S2, the voltage unevenness average value ΔU s % minimum is the optimization target, and the capacitance value C of each secondary parallel capacitor in the secondary parallel capacitor compensation unit is s1 ~C s20 Carry out optimized design.

[0053] Preferably, in operation S2, the capacitance values ​​of the secondary parallel capacitors are uniformly optimized and designed based on the principle that the capacitance values ​​of the secondary parallel capacitors are the same. s1 =C s2 =……=C s20 As a design criterion, the capacitance value C of each secondary parallel capacitor is s1 ~C s20 Perform optimization design to quickly obtain a better compensation solution.

[0054] Operation S3, with the voltage unevenness average minimum and the total output voltage U o Taking the highest value as the goal, the pseudo primary compensation unit is optimized.

[0055] by Figure 4 Taking the high-frequency insulation core transformer shown in FIG. 1 as an example, the number of segment layers N=20, in operation S3, the voltage unevenness average value ΔU s % minimum and maximum total output voltage as the goal, for the false primary capacitor C dp Carry out optimized design.

[0056] Operation S4, adjusting the parameters optimized by operation S2 and operation S3, and determining whether the output distribution of the transformer after adjustment meets the constraint conditions, if so, executing operation S5, otherwise, returning to operation S3.

[0057] Preferably, in operation S4, the capacitance value of each secondary parallel capacitor is independently designed as a principle, and the capacitance value of each secondary parallel capacitor is adjusted respectively. That is, in operation S4, the capacitance value C of each secondary parallel capacitor is s1 , C s2 ,……,C s20 They are not necessarily identical. Based on this, the capacitance value C of each secondary parallel capacitor is s1 ~C s20 Perform optimization design to quickly obtain a better compensation solution.

[0058] Operation S5, with the goal of minimizing the mean value of voltage unevenness, optimizing the coil turns of the secondary winding turns compensation unit, preparing a voltage compensation unit according to the final optimization design result, and using the prepared voltage compensation unit to perform voltage compensation on the high-frequency insulating core transformer.

[0059] According to an embodiment of the present invention, the secondary coils of the high-frequency insulating core transformer are divided into multiple groups, each group of secondary coils is externally connected to a rectifier circuit, and the outputs of the rectifier circuits are connected in series to output a DC voltage, such as Figure 5 The number of turns of the coil obtained by the optimized design in operation S5 is an integer multiple of the number of turns of the secondary coil connected to each rectifier circuit.

[0060] The preparation of the voltage compensation unit in operation S5 includes: according to the parameters of the pseudo primary compensation unit finally adjusted in operation S4, a layer of pseudo primary magnetic core is set at the top of the high-frequency insulating core transformer; according to the capacitance value of each secondary parallel capacitor finally adjusted in operation S4, a compensation capacitor is connected in parallel to the front end of each secondary winding basic output unit of the high-frequency insulating core transformer; according to the number of coil turns optimized in operation S5, a compensation coil is set, and the compensation coil is connected in series with the secondary coil of the high-frequency insulating core transformer.

[0061] The embodiment of the present invention also provides a voltage compensation device for a high-frequency insulating core transformer. The voltage compensation device includes a pseudo primary compensation unit, a secondary shunt capacitor compensation unit and a secondary winding turns compensation unit, and its parameters are as described above. Figure 1-Figure 5 The voltage compensation method for the high-frequency insulating core transformer shown is designed and will not be described in detail here.

[0062] It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A voltage compensation method for a high-frequency insulating core transformer, characterized in that: include: S1, establishing an equivalent circuit model of a high-frequency insulating core transformer and a voltage compensation unit thereof, wherein the voltage compensation unit includes a pseudo primary compensation unit, a secondary shunt capacitor compensation unit and a secondary winding turns compensation unit; S2, optimizing the capacitance value of each secondary shunt capacitor in the secondary shunt capacitor compensation unit with the goal of minimizing the voltage unevenness mean value, wherein the voltage unevenness mean value is the weighted sum of the voltage unevenness of the transformer under no-load, half-load and full-load conditions; S3, optimizing the design of the pseudo primary compensation unit with the goal of minimizing the voltage unevenness mean and maximizing the total output voltage; the voltage unevenness mean is: ΔU s %=w1×ΔU sI %+w2×ΔU sII %+w3×ΔU sIII % Among them, ΔU s % is the mean value of the voltage unevenness, ΔU sI %, ΔU sII %, ΔU sIII % are the voltage unevenness of the transformer under no-load, half-load and full-load conditions, w1 is the no-load weighting coefficient, w2 is the half-load weighting coefficient, w3 is the full-load weighting coefficient, U sImax , U sImin are the maximum output voltage and minimum output voltage of each secondary of the transformer under no-load conditions, U sIImax , U sIImin are the maximum output voltage and minimum output voltage of each secondary of the transformer under half-load condition, U sIIImax , U sIIImin They are the maximum output voltage and minimum output voltage of each secondary of the transformer under full load conditions respectively; S4, adjusting the parameters after the optimization design of S2 and S3, and judging whether the output distribution of the transformer after adjustment meets the constraint conditions, if so, executing S5, otherwise, returning to S3; S5, with the goal of minimizing the mean value of the voltage unevenness, optimizing the design of the coil turns of the secondary winding turns compensation unit, preparing the voltage compensation unit according to the final optimization design result, and using the prepared voltage compensation unit to perform voltage compensation on the high-frequency insulating core transformer; the preparation of the voltage compensation unit includes: According to the pseudo primary compensation unit parameters finally adjusted in S4, a pseudo primary magnetic core is arranged on the top of the high-frequency insulating core transformer; According to the capacitance value of each secondary parallel capacitor finally adjusted in S4, a compensation capacitor is connected in parallel to the front end of each secondary winding basic output unit of the high-frequency insulating core transformer; According to the number of coil turns obtained by the optimized design in S5, a compensation coil is provided, and the compensation coil is connected in series with the secondary coil of the high-frequency insulating core transformer.

2. The voltage compensation method for a high-frequency insulating core transformer according to claim 1, characterized in that: In S2, the capacitance values ​​of the secondary parallel capacitors are uniformly optimized based on the principle that the capacitance values ​​of the secondary parallel capacitors are the same.

3. The voltage compensation method for a high-frequency insulating core transformer according to claim 1, characterized in that: In S4, the capacitance value of each secondary parallel capacitor is independently designed as a principle, and the capacitance value of each secondary parallel capacitor is adjusted respectively.

4. The voltage compensation method for a high-frequency insulating core transformer according to claim 1, characterized in that: The secondary coils of the high-frequency insulating core transformer are divided into multiple groups, each group of secondary coils is externally connected to a rectifier circuit, and the outputs of each rectifier circuit are connected in series to output a DC voltage; the number of coil turns obtained by the optimized design in S5 is an integer multiple of the number of secondary coil turns corresponding to each rectifier circuit.

5. The voltage compensation method for a high-frequency insulating core transformer according to claim 1, characterized in that: The total output voltage is: Among them, U o is the total output voltage, n c is the number of magnetic core columns of the high-frequency insulating core transformer, N is the number of segmented layers of the high-frequency insulating core transformer, and U i is the DC voltage output by the i-th level winding.

6. A voltage compensation device for a high-frequency insulating core transformer, characterized in that: The voltage compensation device is designed by the voltage compensation method for a high-frequency insulating core transformer as described in any one of claims 1 to 5.

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