CN109245501A

CN109245501A - A kind of isolated power supply applied to plural serial stage IGBT

Info

Publication number: CN109245501A
Application number: CN201811273168.4A
Authority: CN
Inventors: 陈庆国; 卢华鑫; 程嵩
Original assignee: Harbin University of Science and Technology
Current assignee: Harbin University of Science and Technology
Priority date: 2018-10-30
Filing date: 2018-10-30
Publication date: 2019-01-18
Anticipated expiration: 2038-10-30
Also published as: CN109245501B

Abstract

The invention relates to an isolated power supply, in particular to an isolated power supply applied to multi-stage series-connected IGBTs. The problems brought by the multi-level IGBT series structure to the power supply are: the IGBTs at all levels are connected in series, and the emitter of each level has a different potential to the ground, so the power supply of each level of IGBT needs to be isolated; The ground voltage of the power supply of the IGBT is different, so the requirements for the insulation strength of the power supply of the IGBT at all levels are also different. In order to solve the above problems, the generally adopted method is to use a current bus-type isolated drive power supply. The disadvantage of this method is that each transformer is unidirectional excitation, and the utilization rate of the magnetic core is low. Due to the deficiencies of the existing methods, it is necessary to invent a new type of isolated driving power supply structure, which can improve the utilization rate of the magnetic core under the premise of satisfying the isolation power supply of multi-level series IGBTs.

Description

A kind of isolated power supply applied to plural serial stage IGBT

Technical field

The present invention relates to a kind of isolated power supplies, more particularly, to a kind of applied to the isolated of plural serial stage IGBT Power supply.

Technical background

IGBT is a kind of typical switching device, it has the characteristics that, and input impedance is high, conduction voltage drop is small, is very suitable to answer It is passed for converter system such as alternating current generator, frequency converter, Switching Power Supply, lighting circuit, traction that DC voltage is 600V or more It is dynamic to wait fields；Voltage class is improved frequently with the concatenated structure of multistage IGBT in practice.

The problem of using the concatenated structure of multistage IGBT to bring to power supply has: 1. IGBT at different levels are and each for series connection All there is different current potentials in the emitter of grade, so the power supply of every grade of IGBT is isolated over the ground；2. IGBT at different levels Power supply voltage-to-ground it is all different, so the requirement of the dielectric strength of the electric power supply of power supply of IGBT at different levels is also different.

In order to solve problem above, the method generally used is the isolation drive power supply using current bus bar type；This side Method feature is: 1. every level-one IGBT are equipped with a transformer, and transformer is using magnetic ring transformer；2. the one of magnetic ring transformer Secondary winding only has a circle；And an ac bus is shared, this root bus passes through the center of all transformer magnet rings.

This method is disadvantageous in that each transformer is unidirectional excitation, and magnetic core utilization rate is low.Due to existing The deficiency of method needs to invent a kind of novel isolation drive power supply structure, in the isolation power supply for being both able to satisfy plural serial stage IGBT Under the premise of, and the utilization rate of magnetic core can be improved.

Summary of the invention

The object of the invention is to combine the requirement of plural serial stage IGBT power supply, design a kind of applied to plural serial stage The isolated power supply of IGBT.

The purpose of the present invention can be achieved through the following technical solutions: a kind of applied to the isolated of plural serial stage IGBT Power supply includes: DC source, two MOSFET, two ac bus, PWM controller, N number of magnetic ring transformer, N number of rectification mould Block, insulation tube.

The DC source is the main power source of the isolated power supply of plural serial stage IGBT；The output end of DC source and two The end A of ac bus is connected.

The MOSFET, effect are the flow directions for changing electric current in two ac bus；The source of two MOSFET Pole is connected to the ground；The grid of two MOSFET is connect with two output signal ends of PWM controller respectively；The leakage of two MOSFET Pole is connected with the end B of two ac bus respectively.

Two ac bus, function as the primary side of N number of magnetic ring transformer；Two ac bus have the end A With the end B；The end A of two ac bus and the output end of DC source connect；The end B of two ac bus respectively with two MOSFET Drain electrode connection；Two ac bus are passed through from the center of N number of magnetic ring transformer；It is put to improve insulation for two ac bus It sets in insulation tube.

The magnetic ring transformer, effect first is that carry out electrical isolation to ac bus and secondary coil, effect second is that into Row energy transmission；The magnetic core of magnetic ring transformer is used using ferrite；Magnetic ring transformer primary side is two ac bus；Two Ac bus is passed through from the center of N number of magnetic ring transformer；The secondary side of magnetic ring transformer is multiturn coil；Each magnet ring transformation The secondary coil of device is connected with the input terminal of rectification module corresponding thereto.

The PWM controller controls the conducting and shutdown of two MOSFET；Two output signal ends of PWM controller with It is connected respectively with the grid of two MOSFET.

The AC signal that the secondary side of magnetic ring transformer exports is rectified into direct current by the rectification module；Each rectification mould The input terminal of block is connected with the secondary coil of magnetic ring transformer corresponding thereto；The output end of each rectification module and phase The load answered is connected.

The effect of the insulation tube is to reinforce the dielectric strength of magnetic ring transformer primary and secondary side.

Detailed description of the invention

Fig. 1 is a kind of isolated power supply schematic diagram applied to plural serial stage IGBT.

Fig. 2 is insulation system schematic diagram.

Specific embodiment

The present invention is described in detail with specific embodiment below in conjunction with the accompanying drawings；The present embodiment is with technical solution of the present invention Premised on implemented, the detailed implementation method and specific operation process are given, but protection scope of the present invention is not limited to Following embodiments.

A kind of isolated power supply applied to plural serial stage IGBT, effect is in the concatenated application of multistage IGBT In the case of, a kind of efficient, reliable power supply is provided；It is a kind of isolation applied to plural serial stage IGBT as shown in Fig. 1 Formula power supply schematic diagram；A kind of isolated power supply applied to plural serial stage IGBT includes: DC source 1, MOSFET2-1 With 2-2, ac bus 3-1 and 3-2, magnetic ring transformer 4-1 ~ 4-N, rectification module 5-1 ~ 5-N, PWM controller 6, insulation tube 7.

All there are two terminals by ac bus 3-1 and ac bus 3-2, labeled as the end A and the end B；Ac bus 3-1 and friendship The end A of stream bus 3-2 is connected with the output end of DC source 1；The end B of ac bus 3-1 and the drain electrode of MOSFET2-1 connect；It hands over The drain electrode at the end B and MOSFET2-2 of flowing bus 3-2 connects.

There are two output ends for PWM controller 6, connect respectively with the grid of MOSFET2-1 and MOSFET2-2；PWM controller 6 output is the square-wave signal of two-way complementation, for driving MOSFET2-1 and MOSFET2-2；MOSFET2-1 with MOSFET2-2 alternate conduction under the control of PWM controller 6 makes to be alternately present electricity in ac bus 3-1 and ac bus 3-2 Stream.

Ac bus 3-1 and ac bus 3-2 passes through the center of magnetic ring transformer 4-1 ~ 4-N；Ac bus 3-1 with exchange The electric current being alternately present in bus 3-2 can generate bidirectional excitation in magnetic ring transformer 4-1 ~ 4-N；Magnetic ring transformer 4-1 ~ 4- N is by the energy of primary side from being transferred to secondary side；The input of the secondary coil and rectification module 5-1 ~ 5-N of magnetic ring transformer 4-1 ~ 4-N End connects one to one；It is mutually isolated between the output end of rectification module 5-1 ~ 5-N.

Fig. 2 is insulation system schematic diagram；In order to reinforce the dielectric strength of magnetic ring transformer 4-1 ~ 4-N primary and secondary side；? Insulation tube 7 is put on outside stream bus 3-1 and ac bus 3-2.

Claims

1. an isolated power supply applied to multi-stage series IGBT; it is characterized in that, comprising: DC source, two MOSFETs, two AC bus bars, PWM controller, N magnetic ring transformers, N rectifier modules, insulation Tube.

2 . The DC source according to claim 1 , wherein it is a main power source of an isolated power supply of multi-stage series IGBTs. 3 .

3. The two AC busbars according to claim 1, wherein each of the two AC busbars has two terminals, which are marked as A terminal and B terminal; the A terminal of the two AC busbars and the output of the DC source 1 The terminals are connected; the B terminals of the two AC bus bars are connected to the drain of the MOSFET.

4. The two MOSFETs according to claim 1, wherein the functions of the two MOSFETs are to change the flow direction of the current in the two AC bus bars; the sources of the two MOSFETs are connected to the ground; the gates of the two MOSFETs are The poles are respectively connected with the two output signal terminals of the PWM controller; the drains of the two MOSFETs are respectively connected with the B terminals of the two AC bus bars.

5. PWM controller according to claim 1, is characterized in that, PWM controller has two output terminals, is connected with the gate of two MOSFETs respectively; The output of PWM controller is two-way complementary square wave signal , for driving two MOSFETs.

6 . The two AC bus bars according to claim 1 , wherein, under the control of the PWM controller, currents appear alternately in the two AC bus bars. 7 .

7. The two AC busbars according to claim 1, characterized in that, passing through the center of the toroidal transformer; bidirectional excitation is generated in the toroidal transformer.

8 . The N magnetic toroidal transformers according to claim 1 , wherein the magnetic core of the magnetic toroidal transformer adopts ferrite. 9 .

9. The N magnetic toroidal transformers according to claim 1, wherein the primary side of the magnetic toroidal transformer is two AC bus bars; the two AC bus bars pass through the centers of the N magnetic toroidal transformers; The side is a multi-turn coil; the secondary side coil of each magnetic toroidal transformer is connected to the input end of the corresponding rectifier module.

10. The N rectifier modules according to claim 1, wherein the AC signal output by the secondary side of the toroidal transformer is rectified into DC; the input end of each rectifier module and the secondary The side coils are connected; the output end of each rectifier module is connected with the corresponding load.

11. The insulating tube according to claim 1, wherein the insulation between the two AC bus bars and the N secondary coils of the magnetic toroidal transformer is improved; the insulating tube is sleeved outside the two AC bus bars; the insulating tube passes through the N center of a toroidal transformer.