High-performance multi-path output driving power supply and low-coupling capacitance multi-path transformer

Abstract

The invention belongs to the technical field of power electronics, and discloses a high-performance multi-output driving power supply and a low-coupling capacitance multi-channel transformer, the low-coupling capacitance multi-channel transformer comprises a pair of magnetic cores, a group of primary windings and N groups of secondary windings, and N is greater than 2; wherein one magnetic core comprises a primary side magnetic column and N secondary side magnetic columns, and the N secondary side magnetic columns evenly surround the circumference with the primary side magnetic column as the circle center; the primary winding is wound on the primary magnetic column, and the N groups of secondary windings are respectively wound on the corresponding secondary magnetic columns; therefore, the coupling capacitance of the primary side and the secondary side is effectively reduced so as to limit the common-mode current excited by the high-speed action of the switching device; based on the multi-output transformer, the invention also provides a high-performance multi-output driving power supply, and a post-stage voltage regulating circuit is configured in the driving power supply, so that the cross regulation rate of multi-output is effectively reduced, and the working consistency and stability of a switching device in a power module are ensured.

Description

Technical Field

[0001] The present invention belongs to the field of power electronics technology, and more specifically, relates to a high-performance multi-output drive power supply and a multi-channel transformer with low coupling capacitance. Background Art

[0002] Silicon carbide (SiC) is a typical representative of the third-generation semiconductor materials. Compared with Si materials, it has a wider bandgap width, higher saturated electron velocity, higher electron mobility, smaller dielectric constant, and better conductivity, making SiC devices have obvious advantages in high-frequency, high-voltage, and high-temperature application scenarios. In recent years, high-voltage SiC-MOSFETs (10 kV / 15 kV) have developed rapidly. Compared with Si-IGBTs of the same voltage level, they have a higher switching frequency, faster switching speed, and smaller switching losses, and are hailed as the "game-changer" for the next generation of medium-voltage and high-voltage power conversion. Replacing high-voltage Si-IGBTs with high-voltage SiC-MOSFETs can greatly increase the switching frequency and achieve the compactification, miniaturization, and light-weighting of medium-voltage converters.

[0003] A high-performance SiC drive module, including a driver and a drive power supply, is an important guarantee for giving full play to the advantages of high-voltage SiC-MOSFETs. Among them, the drive power supply is the power source of the SiC drive module, which not only directly affects the power supply reliability of the SiC-MOSFET driver, but also indirectly affects the working reliability of the entire converter. For a multi-tube integrated high-voltage SiC-MOSFET module, if multiple single-output drive power supplies are used for one-to-one power supply, it will inevitably increase the system cost and complexity, and will also increase the probability of failure, resulting in a decrease in the operating reliability of the device. If a multi-channel isolated output drive power supply is used instead of a single-output drive power supply, only one or a small number of drive power supplies need to be configured one-to-many to meet the drive power supply requirements of the SiC power module, greatly simplifying the power architecture of the SiC drive power supply system.

[0004] Considering the high-voltage and high-speed operating characteristics of high-voltage SiC-MOSFETs, their drive power supplies need to have a relatively high isolation voltage and a low coupling capacitance (<5 pF). The flagship commercial high-isolation drive power supply MGJ2 series represented by Murata in Japan has a primary-secondary coupling capacitance as low as 3 pF, meeting the drive power supply requirements for high-voltage SiC, but it only has a single-channel output; the multi-channel isolation output drive power supply MGJ6 series can directly supply drive power for full-bridge modules and three-phase modules, but the primary-secondary coupling capacitance is as high as 15 pF, and it is unable to suppress the common-mode interference hazards caused by the high-speed operation (>50 V / ns) of high-voltage SiC devices. Currently, the research on high-voltage SiC multi-channel isolation output drive power supplies is still in its infancy. In the prior art, a multi-channel isolation drive power supply with regulated output is disclosed. Its transformer adopts a concentrated winding method, and the primary-secondary coupling capacitance exceeds 7 pF; moreover, there is still coupling between the magnetic paths on the secondary side of the transformer, which is not conducive to the optimization of the transformer structure. A multi-channel output high-isolation drive power supply based on a current transformer is also proposed. Although the primary-secondary coupling capacitance is reduced to 1.67 pF to a certain extent, the multi-channel output depends on a single high-voltage AC current bus, posing a single-point failure risk and insufficient reliability of the drive power supply.

[0005] In addition, the switching performance of high-voltage SiC-MOSFETs is very sensitive to drive voltage fluctuations, and it is necessary to reduce the cross-regulation rate between the outputs of the multi-channel isolation output drive power supply to ensure the stability and consistency of the drive voltage. In the prior art, a multi-channel isolation output drive power supply based on a voltage-clamped forward topology is disclosed, which can expand the output channels by adding secondary windings, but the cross-regulation rate of the multi-channel output is relatively high. There is also a multi-channel output drive power supply based on a "domino"-type wireless power transfer system. However, due to the existence of parasitic parameters, the output voltage at the ports will inevitably decrease step by step, affecting the consistency of the drive voltage. Summary of the Invention

[0006] Aiming at the above defects or improvement requirements of the prior art, the present invention provides a high-performance multi-channel output drive power supply and a multi-channel transformer with low coupling capacitance, aiming to reduce the primary-secondary coupling capacitance of the multi-channel transformer.

[0007] To achieve the above object, the present invention provides a multi-output transformer with low coupling capacitance, including: a pair of magnetic cores, a set of primary windings, and N sets of secondary windings, N>2; wherein, one magnetic core includes one primary magnetic column and N secondary magnetic columns, and the N secondary magnetic columns are evenly arranged around the circumference with the primary magnetic column as the center; the primary winding is wound around the primary magnetic column, and the N sets of secondary windings are respectively wound around the corresponding secondary magnetic columns.

[0008] Further, an air gap is opened in each of the secondary magnetic columns.

[0009] Further, the primary winding and the N secondary windings are wound windings or planar windings based on a printed circuit board.

[0010] The present invention also provides a high-performance multi-channel regulated output drive power supply, comprising: a primary circuit, N secondary circuits, N voltage regulating circuits, and the low-coupling-capacitance multi-output transformer described in any one of the above;

[0011] The input end of the primary circuit is the input end of the multi-channel regulated output drive power supply. The output end of the primary circuit is connected to the input end of the low-coupling-capacitance multi-output transformer. The nth output end of the low-coupling-capacitance multi-output transformer, the nth secondary circuit, and the input end of the nth voltage regulating circuit are connected in sequence. The output ends of the N voltage regulating circuits are respectively the output ends of the multi-channel regulated output drive power supply, where n = 1, 2, …, N;

[0012] The primary circuit is used to convert the input direct current into high-frequency alternating current;

[0013] The low-coupling-capacitance multi-output transformer is used to perform voltage conversion on the high-frequency alternating current and output N paths of high-frequency alternating current;

[0014] The nth secondary circuit is used to convert the high-frequency alternating current output from the nth output of the low-coupling-capacitance multi-output transformer into corresponding direct current;

[0015] The nth voltage regulating circuit includes a main circuit and a control circuit. The main circuit is used to transfer the received direct current to the load. The control circuit is used to perform closed-loop feedback control on the output voltage of the main circuit after sampling, so that when the load or the input of the multi-channel regulated output drive power supply changes within a certain range, the output voltage of the main circuit remains constant.

[0016] Further, the primary circuit includes an inverter circuit and a primary compensation circuit;

[0017] The inverter circuit is used to realize the inversion of the input direct current into high-frequency alternating current; the primary compensation circuit is used to compensate the parasitic parameters of the primary side of the low-coupling-capacitance multi-output transformer.

[0018] Further, the inverter circuit is a single-ended inverter circuit, a push-pull inverter circuit, a half-bridge inverter circuit, or a full-bridge inverter circuit; the primary compensation circuit is a series compensation, a parallel compensation, or a series-parallel compensation circuit.

[0019] Further, each secondary circuit includes a secondary compensation network, a rectifier circuit, and a filter circuit;

[0020] The secondary compensation network is used to compensate the parasitic parameters of the secondary side of the low-coupling-capacitance multi-output transformer;

[0021] The rectifier circuit is used to convert the high-frequency alternating current output from the nth output of the low-coupling-capacitance multi-output transformer into corresponding direct current;

[0022] The filter circuit is used to filter out the AC components in the output voltage of the rectifier circuit.

[0023] Further, the secondary compensation network is a series compensation, parallel compensation or series-parallel compensation network;

[0024] The rectifier circuit is a half-wave rectifier circuit, full-wave rectifier circuit or bridge rectifier circuit.

[0025] Further, the main circuit of each voltage regulating circuit is a buck converter, boost converter or buck-boost converter.

[0026] The present invention also provides a driving power supply method for a multi-tube integrated switching device in a medium-voltage converter, including: using the high-performance multi-channel regulated output driving power supply described in any one of the above to drive and supply power to the multi-tube integrated switching device in the medium-voltage converter.

[0027] Generally speaking, through the above technical solutions conceived by the present invention, the following beneficial effects can be achieved:

[0028] (1) In the low-coupling-capacitance multi-output transformer designed by the present invention, the secondary magnetic posts are evenly surrounded on the circumference with the primary magnetic post as the center, and the primary winding and multiple secondary windings are respectively wound on different magnetic posts, reducing the facing area between the primary and secondary windings, effectively reducing the direct coupling capacitance C pw-sw between the primary and secondary windings, and further greatly reducing the equivalent coupling capacitance C ps between the primary and secondary windings of the multi-output transformer; moreover, compared with the multi-output transformer in which the primary winding and each secondary winding are wound on the same magnetic post, the electric field coupling between the primary winding and each secondary winding affects each other, making it difficult to optimize the primary-secondary coupling capacitance; in the multi-output transformer designed in the present invention, the mutual influence of the electric field coupling between the primary winding and each secondary winding can be reduced, and the law of the transformer coupling capacitance changing with the structural parameters is clear and intuitive (when the radii of the primary and secondary windings increase, the distance between the winding and the corresponding magnetic post will increase, so the coupling capacitance between the winding and the magnetic core will decrease, while the distance between the primary and secondary windings decreases, which will cause the direct coupling capacitance C pw-sw between the primary and secondary windings to increase), thereby reducing the optimization difficulty of the primary-secondary coupling capacitance and finally reducing the common-mode current. The test examples also verify that the equivalent coupling capacitance in the present invention can be as low as 0.53 pF, far lower than the prior art.

[0029] (2) The low-coupling capacitance multi-output transformer proposed by the present invention has multiple secondary magnetic columns in the magnetic core evenly arranged on a circumference with the primary magnetic column as the center, which can ensure the symmetry of the entire magnetic core, and further ensure the consistency of the outputs of each path of the transformer. When it is applied to a multi-path regulated output drive power supply, it can guarantee the consistency of the outputs of each path of the drive power supply.

[0030] (3) Further, based on the low-coupling capacitance multi-output transformer designed by the present invention, by winding N groups of secondary windings on different secondary magnetic columns respectively, the magnetic paths of the secondary windings are separated in space. An air gap is opened in each secondary magnetic column to increase the magnetic resistance of the secondary magnetic path, realizing the magnetic flux decoupling of N groups of secondary sides, that is, realizing the magnetic path decoupling of multiple secondary sides, and further realizing the decoupling between the outputs of multiple secondary sides. When it is applied to a multi-path regulated output drive power supply, it reduces the cross-regulation rate between the outputs of each path of the multi-path regulated output drive power supply.

[0031] (4) Further, based on the low-coupling capacitance multi-output transformer designed by the present invention, the present invention provides a new topology structure of a multi-path regulated output drive power supply. This multi-path regulated output drive power supply is a high-performance multi-path regulated output drive power supply with low cross-regulation rate and low coupling capacitance. Specifically, by setting a corresponding voltage regulating circuit for each path of the secondary circuit, taking the output voltage of each voltage regulating circuit as the control quantity, and performing closed-loop control on the output voltage, when the load or the input of the multi-path regulated output drive power supply changes within a certain range, the output voltages of each path of the main circuit remain constant, realizing the independent regulation of the outputs of each path of the multi-path regulated output drive power supply. In this way, the N output voltages of the drive power supply are not only immune to the influence of the input voltage fluctuation, but also do not change with the change of the load of this branch, and are not interfered by the load changes of the remaining output branches, reducing the line regulation rate, load regulation rate and cross-regulation rate of the multi-path drive power supply, and improving the stability of the high-voltage SiC drive power supply. Theoretically, the cross-regulation rate between the outputs of each path of the multi-path regulated output drive power supply in the present invention is 0. In addition, only one low-coupling multi-output transformer is used in the present invention to realize N outputs, reducing the risk of single-point failure and improving the reliability of the SiC drive power supply.

[0032] (5) The low-coupling capacitance multi-output transformer designed by the present invention has N groups of secondary windings symmetrically arranged on a circumference with the primary winding as the center. When it is applied to a multi-path regulated output drive power supply, it ensures the symmetry of the circuit parameters and magnetic path parameters of multiple secondary sides, and improves the consistency of the drive voltage.

[0033] (6) Compared with single-output drive power supplies and dual-output drive power supplies, the drive power supply proposed by the present invention has multiple mutually isolated output ports, and can simultaneously provide reliable drive power supply for the drivers of multi-tube integrated switch device modules in medium-high voltage converters one-to-many, simplifying the high-voltage SiC drive power supply system. Description of the Drawings

[0034] Figure 1 It is an example diagram of the multi-output transformer in the embodiment of the present invention;

[0035] Figure 2 It is the architecture diagram of the multi-channel regulated output drive power supply in the embodiment of the present invention;

[0036] Figure 3 It is a topology structure diagram of a four-channel regulated output drive power supply in the embodiment of the present invention;

[0037] Figure 4 It is an example diagram of a four-output transformer in the embodiment of the present invention;

[0038] Figure 5 It is the steady-state working waveform of the multi-channel regulated output drive power supply in the embodiment of the present invention. The solid line in the figure is the output voltage waveform, and the dotted line is the output current waveform;

[0039] Figure 6 It is the dynamic working waveform of the multi-channel regulated output drive power supply in the embodiment of the present invention when the input voltage changes suddenly. The solid line in the figure is the output voltage waveform, and the dotted line is the output current waveform;

[0040] Figure 7 It is the dynamic working waveform of the multi-channel regulated output drive power supply in the embodiment of the present invention when the load changes suddenly. The solid line in the figure is the output voltage waveform, and the dotted line is the output current waveform;

[0041] Figure 8 It is the electric field intensity distribution diagram of the multi-output transformer in the embodiment of the present invention;

[0042] Figure 9 It is an application example of the multi-channel regulated output drive power supply in the embodiment of the present invention; (a)-(c) in the figure are respectively the multi-channel regulated output drive power supply used for the full-bridge switch device module, the T-shaped three-level bridge arm module, and the three-phase switch device module. Detailed Embodiments

[0043] In order to make the objectives, technical solutions and advantages of the present invention more clear and understandable, the present invention will be 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 used 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.

[0044] In the present invention, terms such as "first" and "second" in the present invention and the accompanying drawings are used to distinguish similar objects and do not necessarily need to describe a specific order or sequence.

[0045] Embodiment 1

[0046] As shown in Figure 1 the drawings, an embodiment of the present invention provides a low-coupling-capacitance multi-output transformer, including: a pair of magnetic cores, a set of primary windings, and N sets of secondary windings, where N>2. One of the magnetic cores includes a primary magnetic column and N secondary magnetic columns, and the N secondary magnetic columns are evenly arranged around a circumference with the primary magnetic column as the center; the primary winding is wound around the primary magnetic column, and the N sets of secondary windings are respectively wound around the corresponding secondary magnetic columns; the primary winding is connected to the output end of the primary circuit, and the N sets of secondary windings are respectively connected to the input ends of N secondary circuits.

[0047] The multi-output transformer in the embodiment of the present invention is used to achieve voltage matching between the primary and secondary sides and meet the high isolation requirements (>3 kV) of the driving power supply.

[0048] Furthermore, in the low-coupling-capacitance multi-output transformer in the embodiment of the present invention, each secondary magnetic column is provided with an air gap. By winding the N sets of secondary windings around different secondary magnetic columns respectively, the magnetic paths of the secondary windings are separated in space. Opening an air gap in each secondary magnetic column increases the magnetic resistance of the secondary magnetic path, realizes the magnetic flux decoupling of the N sets of secondary sides, that is, realizes the magnetic path decoupling of multiple secondary sides, and further realizes the decoupling between multiple secondary side outputs. When it is applied to a multi-channel regulated output driving power supply, the cross-regulation rate between the outputs of the multi-channel regulated output driving power supply is reduced.

[0049] Preferably, to meet the high isolation requirements of the driving power supply, the primary winding and the N sets of secondary windings can both adopt wound windings or planar windings based on printed circuit boards.

[0050] Based on the above-designed multi-output transformer, the equivalent coupling capacitance C between the primary winding of the multi-output transformer and a set of secondary windings ps is:

[0051]

[0052] where C pw-swis the direct coupling capacitance between the primary winding and a set of secondary windings, C pw-c is the coupling capacitance between the primary winding and the entire magnetic core, C sw-c is the coupling capacitance between a set of secondary windings and the entire magnetic core, is used to characterize the equivalent coupling capacitance between the primary winding and a set of secondary windings and the magnetic core.

[0053] Based on the above formula, it can be found that when the radius of the primary winding or the secondary winding increases, the distance between the winding and the corresponding magnetic column will increase. Therefore, the coupling capacitance C pw-c and C sw-c will decrease, thereby reducing the equivalent coupling capacitance C ps . When the distance between the primary and secondary windings decreases, it will cause the direct coupling capacitance C pw-sw between the primary and secondary windings to increase; therefore, with the help of finite element simulation, the optimization of the transformer structure parameters can be realized in the multi-output transformer designed in the present invention to minimize the equivalent coupling capacitance C ps . Therefore, based on the designed multi-output transformer, it is possible to reduce the mutual influence of electric field coupling between the primary winding and each set of secondary windings. The law of variation of the transformer coupling capacitance with the structure parameters is clear and intuitive, thereby reducing the optimization difficulty of the primary and secondary coupling capacitances.

[0054] In particular, the multi-output transformer winds the primary winding and multiple secondary windings on different magnetic columns respectively, reducing the facing area between the primary and secondary windings, and effectively reducing the direct coupling capacitance C pw-sw between the primary and secondary windings, thereby greatly reducing the equivalent coupling capacitance C ps between the primary and secondary windings of the multi-output transformer.

[0055] Embodiment 2

[0056] As Figure 2 shown, the embodiment of the present invention provides a high-performance multi-channel regulated output drive power supply, including a primary circuit, a multi-output transformer, N secondary circuits and N voltage regulating circuits, N>2; wherein, the multi-output transformer is the low-coupling-capacitance multi-output transformer in the above Embodiment 1.

[0057] The input end of the primary circuit is used as the input end of the multi-channel regulated output drive power supply. The output end of the primary circuit is connected to the input end of the multi-output transformer. The nth output end of the multi-output transformer, the nth secondary circuit and the input end of the nth voltage regulating circuit are connected in sequence. The N output ends of the N voltage regulating circuits are respectively used as the output ends of the multi-channel regulated output drive power supply; wherein, n = 1, 2,..., N.

[0058] The primary circuit is used to convert the input direct current into high-frequency alternating current;

[0059] The multi-output transformer is used to transform the high-frequency alternating current output by the primary circuit, and output N paths of high-frequency alternating current;

[0060] The nth secondary circuit is used to convert the high-frequency alternating current output by the nth path of the multi-output transformer into the corresponding direct current;

[0061] The nth voltage regulating circuit includes a main circuit and a control circuit. The main circuit is used to transfer the received direct current to the load, and the control circuit is used to sample the voltage V at the output end of the main circuit on (n = 1, 2, …, N), and perform closed-loop feedback control on the sampled voltage, so that when the load or the input of the multi-channel regulated output driving power supply changes within a certain range, the output voltage V of the main circuit on (n = 1, 2, …, N) remains constant.

[0062] Preferably, the primary circuit includes an inverter circuit and a primary compensation circuit. Among them, the inverter circuit is used to realize the inversion of direct current to alternating current, and can adopt a single-ended inverter circuit, a push-pull inverter circuit, a half-bridge inverter circuit, a full-bridge inverter circuit, etc.; the primary compensation circuit is used to compensate the parasitic parameters of the primary side of the multi-output transformer, and can adopt series compensation, parallel compensation, and series-parallel compensation, etc.

[0063] Preferably, each secondary circuit includes a secondary compensation network, a rectifier circuit, and a filter circuit. The secondary compensation network is used to compensate the parasitic parameters of the secondary side of the multi-output transformer, and can adopt series compensation, parallel compensation, and series-parallel compensation, etc.; the rectifier circuit is used to realize the rectification of alternating current to direct current, and can adopt a half-wave rectifier circuit, a full-wave rectifier circuit, and a bridge rectifier circuit, etc.; the filter circuit is used to filter out the alternating components in the output voltage of the rectifier circuit to obtain a stable direct current voltage.

[0064] In the embodiments of the present invention, each voltage regulating circuit is used to stabilize the output voltage of the driving power supply so that it is not affected by the input voltage fluctuation and the load change.

[0065] Preferably, the main circuit of each voltage regulating circuit adopts a switching power supply such as a buck converter, a boost converter, or a buck-boost converter, and the specific circuit structure is determined according to the application requirements of the load.

[0066] Next, based on Figure 3 , and in combination with Figures 4 - 9 the relevant performances of the multi-output transformer and the multi-channel regulated output driving power supply in the present invention are tested. V in the figure in is the input voltage of the multi-channel regulated output driving power supply, C p is the primary series compensation capacitor, C sn are the nth secondary series compensation capacitors respectively, V on are the output voltages of the nth branch respectively, Ion They are the output currents of the nth branch respectively. In the embodiments of the present invention, n = 1, 2, 3, 4, that is, N = 4.

[0067] Figure 3 Fig. shows an example diagram of the four-way regulated output drive power supply proposed in the embodiments of the present invention.

[0068] In the figure, the inverter circuit adopts a half-bridge inverter circuit; both the primary compensation network and the secondary compensation network adopt series compensation, where C p compensates for the primary leakage inductance and self-inductance of the compensation transformer, and C sn (n = 1, 2, 3, 4) compensates for the secondary leakage inductance and self-inductance of the compensation transformer; the rectifier circuit adopts a bridge rectifier circuit; the filter circuit adopts an inductance-capacitance low-pass filter circuit; the voltage regulation circuit adopts a Boost boost conversion circuit.

[0069] Figure 4 Fig. shows an example diagram of the four-output transformer proposed in the embodiments of the present invention. In the figure, the winding adopts a planar winding based on a printed circuit board. For the readability of the example diagram, the wiring and terminals other than the winding are hidden.

[0070] Test Example 1:

[0071] Figure 5 Fig. shows the steady-state working waveforms of the multi-way regulated output drive power supply in the embodiments of the present invention under rated conditions. Specifically, taking the four-way regulated output drive power supply as an example. It can be seen that the proposed multi-way regulated output drive power supply realizes stable multi-way output and can be used to provide reliable drive power supply for the drivers of multi-tube integrated switch device modules from one to multiple locations.

[0072] The main parameters used in Test Example 1 are as follows:

[0073] ● Input voltage range: 40V - 60V

[0074] ● Rated input voltage: 48V

[0075] ● Single-channel rated output voltage: 24V

[0076] ● Single-channel rated output current: 0.1A

[0077] ● Number of output branches: 4

[0078] ● Primary circuit switching frequency: 100kHz

[0079] ● Voltage regulation circuit switching frequency: 200kHz

[0080] ● Filter circuit inductor: 15μH

[0081] ● Filter circuit capacitor: 10μF

[0082] ● Inductor of the Boost voltage regulating circuit: 68 μH

[0083] ● Output capacitor: 10 μF

[0084] Test Example Two:

[0085] Taking the four - way regulated output driving power supply in the embodiment of the present invention as an example, Figure 4 and Figure 5 its dynamic working waveforms are given.

[0086] Figure 6 The output voltage waveforms of the four - way regulated output driving power supply are given when the input voltage varies between 40V and 60V. It can be seen that when the input voltage changes, the multi - way output voltages of the multi - way regulated output driving power supply all remain stable, having good linear regulation characteristics.

[0087] Figure 7 The working waveforms of the four - way regulated output driving power supply are given when the load of branch 2 mutates between half - load and full - load. In the figure, the solid line is the output voltage waveform and the dashed line is the output current waveform. It can be seen that during the load mutation process of branch 2, not only the output voltage of branch 2 itself remains stable, but the output voltages of the other branches also remain stable. Therefore, the multi - way regulated output driving power supply has good load regulation characteristics and cross - regulation characteristics.

[0088] Test Example Three:

[0089] Figure 8 The key electric field intensity distribution map of the four - output transformer in the embodiment of the present invention is given. It can be seen that the maximum electric field intensity in the transformer is 2.85 kV / mm. Considering that the breakdown field strength of air is 3 kV / mm, this transformer meets the high - insulation requirements of the high - voltage SiC driving power supply. The coupling capacitances between the four secondary windings and the primary winding of the transformer are C ps1 = 0.53 pF, C ps2 = 0.53 pF, C ps3 = 0.55 pF, C ps4 = 0.55 pF. It can be seen that this transformer meets the low - coupling capacitance requirements of the high - voltage SiC driving power supply.

[0090] The main parameters used in Test Example Three are as follows:

[0091] ● Working voltage: 6 kV

[0092] ● Core material: Dongci DMR95

[0093] ● Effective cross - sectional area of the core: 66 mm 2

[0094] ● Effective magnetic path length of the magnetic core: 40 mm

[0095] ● Air gap length: 0.2 mm

[0096] ● Winding thickness: 2 oz

[0097] ● Winding width: 30 mil

[0098] ● Number of turns of the primary winding: 4 turns

[0099] ● Number of turns of the secondary winding: 2 turns

[0100] ● Side length of the primary winding: 6.6 mm

[0101] ● Side length of the secondary winding: 4.3 mm

[0102] Application examples:

[0103] Figure 9 Examples (a)-(c) in [reference] respectively show the application examples of the multi-channel regulated drive power supply proposed by the present invention in a full-bridge switching device module, a T-shaped three-level bridge arm module, and a three-phase switching device module. It can be seen that the multi-channel regulated drive power supply can stably and reliably supply power to the drivers of multi-tube integrated switching device modules in medium- and high-voltage converters one-to-many.

[0104] Those skilled in the art can easily understand 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 replacements, and improvements made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A low coupling capacitance multi-output transformer, characterized in that: include: A pair of magnetic cores, a group of primary windings and N groups of secondary windings, N>2; wherein a magnetic core includes a primary magnetic column and N secondary magnetic columns, and the N secondary magnetic columns are evenly surrounded on a circle with the primary magnetic column as the center; the primary winding is wound on the primary magnetic column, and the N groups of secondary windings are respectively wound on corresponding secondary magnetic columns.

2. The low coupling capacitance multi-output transformer according to claim 1, characterized in that: Each of the secondary magnetic columns has an air gap.

3. The low coupling capacitance multi-output transformer according to claim 2, characterized in that: The primary winding and the N groups of secondary windings are wound wire windings or planar windings based on a printed circuit board.

4. A high-performance multi-channel voltage-stabilized output driving power supply, characterized in that: include: A primary circuit, N secondary circuits, N voltage regulating circuits, and a low-coupling capacitor multi-output transformer as claimed in any one of claims 1 to 3; The input end of the primary circuit is the input end of the multi-channel voltage-stabilized output driving power supply, the output end of the primary circuit is connected to the input end of the low-coupling capacitor multi-output transformer, the nth output end of the low-coupling capacitor multi-output transformer, the nth secondary circuit and the input end of the nth voltage regulating circuit are connected in sequence, and the output ends of the N-channel voltage regulating circuits are the output ends of the multi-channel voltage-stabilized output driving power supply, n=1, 2, ..., N; The primary circuit is used to convert the input direct current into high-frequency alternating current; The low-coupling capacitance multi-output transformer is used to perform voltage conversion on the high-frequency alternating current and output N high-frequency alternating currents; The nth secondary circuit is used to convert the high-frequency alternating current outputted by the nth output transformer of the low-coupling capacitor into a corresponding direct current; The nth voltage regulating circuit includes a main circuit and a control circuit, wherein the main circuit is used to transfer the received direct current to the load, and the control circuit is used to perform closed-loop feedback control on the sampled output voltage of the main circuit, so that when the load or the input of the multi-channel voltage-regulated output driving power supply changes within a certain range, the output voltage of the main circuit remains constant.

5. The high-performance multi-channel voltage-stabilized output driving power supply according to claim 4, characterized in that: The primary circuit includes an inverter circuit and a primary compensation circuit; The inverter circuit is used to realize the inversion of input direct current into high-frequency alternating current; the primary side compensation circuit is used to compensate for the parasitic parameters of the primary side of the low-coupling capacitor multi-output transformer.

6. The high-performance multi-channel voltage-stabilized output driving power supply according to claim 5, characterized in that: The inverter circuit is a single-ended inverter circuit, a push-pull inverter circuit, a half-bridge inverter circuit or a full-bridge inverter circuit; the primary side compensation circuit is a series compensation circuit, a parallel compensation circuit or a series-parallel compensation circuit.

7. The high-performance multi-channel voltage-stabilized output driving power supply according to claim 4, characterized in that: Each secondary circuit includes a secondary compensation network, a rectifier circuit and a filter circuit; The secondary side compensation network is used to compensate for the parasitic parameters of the secondary side of the low coupling capacitor multi-output transformer; The rectifier circuit is used to convert the high-frequency alternating current outputted by the nth path of the low-coupling capacitor multi-output transformer into a corresponding direct current; The filter circuit is used to filter out the AC component in the output voltage of the rectifier circuit.

8. The high-performance multi-channel voltage-stabilized output driving power supply according to claim 7, characterized in that: The secondary side compensation network is a series compensation, parallel compensation or series-parallel compensation network; The rectifier circuit is a half-wave rectifier circuit, a full-wave rectifier circuit or a bridge rectifier circuit.

9. The high-performance multi-channel voltage-stabilized output driving power supply according to claim 4, characterized in that: The main circuit of each voltage regulation circuit is a buck converter, a boost converter or a buck-boost converter.

10. A driving and power supply method for a multi-tube integrated switch device in a medium- and high-voltage converter, characterized in that: include: The high-performance multi-channel voltage-stabilized output driving power supply described in any one of claims 4 to 9 is used to drive and supply power to the multi-tube integrated switching device in the medium and high voltage converter.

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