CN210297566U

CN210297566U - High-reliability high-power case-based medium-high voltage direct current power supply

Info

Publication number: CN210297566U
Application number: CN201921528361.8U
Authority: CN
Inventors: 罗安; 何志兴; 肖牧轩; 徐千鸣; 张浚坤; 周芊帆; 肖子衡; 唐昱煊; 管仁锋; 刘阳; 廖明园
Original assignee: Hunan University
Current assignee: Hunan University
Priority date: 2019-09-16
Filing date: 2019-09-16
Publication date: 2020-04-10
Anticipated expiration: 2029-09-16

Abstract

The utility model discloses a high-reliability high-power case-based medium-high voltage direct current power supply, which comprises a multi-winding phase-shifting transformer and a power module connected in series with output; the multi-winding phase-shifting transformer comprises n secondary windings, and each secondary winding is connected with one power module; all the output ends of the power modules are connected in series; the n secondary windings of the multi-winding phase-shifting transformer are mutually isolated. The utility model discloses the reliability is high, output voltage control range is wide, and output is big, and the power module is insulating to require lowly.

Description

High-reliability high-power case-based medium-high voltage direct current power supply

Technical Field

The utility model relates to a submarine communication power supply, the submarine observation network power supply, high voltage direct current power supply field in the high-power case base of industrial high reliability, especially a high voltage direct current power supply in the high-power case base of high reliability.

Background

With the development of industrial production, the technical progress of various industries and the development of national defense industry, the high-voltage direct-current power supply in the high-reliability high-power case base is widely concerned and applied, and has wide market demand. The high-reliability high-power case-based medium-high voltage direct current power supply is widely applied to the fields of industrial production special power supply, medium-high voltage direct current electrolysis, cross-sea communication, remote electric energy transmission, submarine observation network power supply and the like.

The high-reliability high-power scheme based on diode rectification has uncontrollable output voltage and large voltage fluctuation, is influenced by grid voltage fluctuation, and is difficult to meet the requirements of industrial and domestic application. The thyristor rectification-based high-reliability high-power case-based medium-high voltage direct current power supply is simple in structure, can adjust output voltage, but is low in adjusting speed, long in dynamic adjusting time and large in output voltage fluctuation. The switching direct-current power supply adopting the high-speed controllable power switching tube can obtain accurate direct-current voltage, has good dynamic performance and is widely concerned. However, in order to achieve isolation, a high frequency transformer is generally used for isolation.

When the high-reliability high-power medium-voltage direct current switching device is used for high-reliability high-power medium-voltage direct current flow field, the voltage resistance and the overcurrent capacity of a single switching tube are limited, and a plurality of power modules need to be connected in series and in parallel. A plurality of scholars at home and abroad develop researches on high-power high-reliability high-power case-based medium-high voltage direct current power supplies, including a high-reliability high-power case-based medium-high voltage direct current power supply structure based on a modular multilevel converter, a structure for realizing medium-high voltage by adopting output series connection of isolated DC/DC modules and the like. When medium and high voltage direct current is output, the requirement on the primary and secondary side insulation levels of the high-frequency transformer used by the isolated DC/DC module is high, the size and the manufacturing difficulty of the high-frequency transformer are increased, and the high-power high-frequency transformer is difficult to manufacture. In order to realize accurate control of the output voltage, feedback control needs to be performed on the output voltage and the current signal, but the design difficulty of the control system is increased due to the high potentials of the anode and the cathode of the power module, and the complexity of the control system is increased.

When the existing medium-voltage direct-current power supply is applied to a high-power occasion, because the input end adopts diode rectification, a large amount of harmonic waves can be generated on the alternating-current side, the transformer loss is increased, and the operation of a power grid can be influenced by injecting a large amount of harmonic waves into the power grid.

Disclosure of Invention

The utility model aims to solve the technical problem that, it is not enough to prior art, provide a high voltage direct current power supply in the high reliable high-power case base that reliability and power density are high.

In order to solve the technical problem, the utility model discloses the technical scheme who adopts is: a high-reliability high-power case-based medium-high voltage direct current power supply comprises a multi-winding phase-shifting transformer and a power module with output connected in series; the multi-winding phase-shifting transformer comprises n secondary windings, and each secondary winding is connected with one power module; all the output ends of the power modules are connected in series; the n secondary windings of the multi-winding phase-shifting transformer are mutually isolated.

The power module comprises an AC/DC rectifying circuit and a DC/DC direct-current voltage regulating circuit; the input end of the AC/DC rectifying circuit is connected with the corresponding secondary winding; the output end of the AC/DC rectifying circuit is connected with the input end of the DC/DC direct-current voltage regulating circuit; and the output end of the DC/DC direct-current voltage regulating circuit is connected with the input end of the bypass circuit.

The AC/DC rectification circuit is one of a diode uncontrollable rectification circuit, a thyristor rectification circuit, a Vienna rectification circuit and a PWM rectification circuit.

The DC/DC direct current voltage regulating circuit is one of a Buck circuit, a Boost circuit, a Buck-Boost circuit, a phase-shifted full-bridge direct current conversion circuit and a resonant direct current conversion circuit.

The bypass circuit is a diode which is connected in inverse parallel with the output end of the DC/DC direct-current voltage regulating circuit.

The bypass circuit comprises a bypass switch connected with the DC/DC direct-current voltage regulating circuit in series, and the output end of the bypass switch is connected with a diode in anti-parallel.

Compared with the prior art, the utility model discloses the beneficial effect who has does: the utility model discloses the reliability is high, output voltage control range is wide, and output is big, and the power module is insulating to require lowly. The utility model discloses well multiconductor transformer provides the independent AC input of mutual isolation for power module, and a plurality of power module output are established ties and are obtained well high voltage direct current. The n windings on the secondary side of the phase-shifting transformer are mutually isolated, so that the voltage insulation grade in the power module and the insulation grade of a control system are reduced, and the main circuit and the control circuit structure are simplified; because the power module does not need to deal with the problem of high isolation, the conversion topology of the power module can be greatly simplified and redundant operation can be realized, the reliability and the power density are high, and the power module does not need to carry out feedback control across high voltage so as to simplify a control system; the output of the power modules is connected in series, the output voltage of the power modules can be adjusted, and the number of input operation is increased to expand the output voltage adjusting range of the shore-based high-reliability high-power case-based medium-high voltage direct current power supply.

Drawings

FIG. 1 is a schematic diagram of a high-voltage DC power supply main circuit in a high-reliability high-power shore-based high-reliability high-power case-based of the present invention;

FIG. 2 is a circuit block diagram of a single power module;

FIG. 3 is a diagram of a typical AC/DC rectification circuit in a single power module; among them, FIG. 3 (a) an AC/DC rectifying circuit; FIG. 3(b) a diode unreliable rectifying circuit; FIG. 3(c) a thyristor rectifier circuit; FIG. 3(d) or Vienna rectifier circuit; FIG. 3(e) a PWM rectification circuit based on a fully controlled device;

FIG. 4 is a diagram of a typical DC/DC voltage regulator circuit in a single power module; FIG. 4 (a) a DC/DC regulator circuit; FIG. 4(b) Buck circuit; fig. 4(c) Boost circuit; FIG. 4(d) Buck-Boost circuit; FIG. 4(e) is an isolated DC converter circuit such as a phase-shifted full-bridge DC converter circuit; fig. 4(f) is an isolated resonant dc converter circuit;

FIG. 5 is a diagram of an exemplary bypass circuit in a single power module; FIG. 5(a) a bypass circuit; FIG. 5(b) a diode connected in anti-parallel at the output; the output end of the figure 5(c) is connected with the bypass switch in series and then connected with the diode in anti-parallel at the output end.

Detailed Description

Fig. 1 shows a high voltage dc power supply in a highly reliable high power shore-based highly reliable high power case-based for connection to a medium-high voltage dc bus, in accordance with an embodiment of the present invention. The power supply comprises an alternating current input end, a phase-shifting transformer and n power modules. The multi-winding transformer provides mutually isolated independent alternating current input for the power modules, and the outputs of the power modules are connected in series to obtain medium and high voltage direct current. The secondary side of the phase-shifting transformer comprises n windings, and the n windings are mutually isolated to realize the electrical isolation among the power modules, so that the voltage insulation grade inside the power modules and the insulation grade of a control system are reduced, and the main circuit and the control circuit structure are simplified; the phase-shifting transformer is a power frequency transformer, the requirement of high-power application can be met, and the turn ratio of primary and secondary windings of the transformer is designed according to the grade of direct-current voltage required to be output.

As shown in fig. 2, the circuit structure diagram of a single power module is composed of an AC/DC rectifying circuit, a DC/DC voltage regulating circuit and a bypass circuit. The secondary side winding of the phase-shifting transformer is connected with the input end of the AC/DC rectifying circuit, the output end of the AC/DC rectifying circuit is connected with the input end of the DC/DC direct-current voltage regulating circuit, and the output end of the DC/DC direct-current voltage regulating circuit is connected with the input end of the bypass circuit.

The rectification circuit AC/DC of each power module may be a diode-unreliable rectification circuit fig. 3(b), a thyristor rectification circuit fig. 3(c), a vienna rectification circuit fig. 3(d) or a fully-controlled device based PWM rectification circuit fig. 3 (e).

The DC/DC voltage regulating circuit of each power module may be a non-isolated DC conversion circuit, such as a Buck circuit diagram 4(b), a Boost circuit diagram 4(c), a Buck-Boost circuit diagram 4(d), etc., or an isolated DC conversion circuit, such as a phase-shifted full-bridge DC conversion circuit diagram 4(e), an isolated resonant DC conversion circuit diagram 4(f), etc.

The bypass circuit of each power module can be a diode graph 5(b) which is connected with the output end in an anti-parallel mode, or can be a diode graph 5(c) which is connected with the output end in series with a bypass switch and then connected with the output end in an anti-parallel mode, when the direct current voltage regulating circuit DC/DC of the power module comprises an output diode, the bypass circuit can be omitted, and the output diode is conducted to be a natural bypass when the power module is in fault.

Claims

1. A high-reliability high-power case-based medium-high voltage direct current power supply is characterized by comprising a multi-winding phase-shifting transformer and a power module with output connected in series; the multi-winding phase-shifting transformer comprises n secondary windings, and each secondary winding is connected with one power module; all the output ends of the power modules are connected in series; the n secondary windings of the multi-winding phase-shifting transformer are mutually isolated.

2. The high-reliability high-power case-based medium-high voltage direct current power supply according to claim 1, wherein the power module comprises an AC/DC rectifying circuit and a DC/DC direct current voltage regulating circuit; the input end of the AC/DC rectifying circuit is connected with the corresponding secondary winding; the output end of the AC/DC rectifying circuit is connected with the input end of the DC/DC direct-current voltage regulating circuit; and the output end of the DC/DC direct-current voltage regulating circuit is connected with the input end of the bypass circuit.

3. The high-reliability high-power case-based medium-voltage direct-current power supply according to claim 1, wherein the AC/DC rectification circuit is one of a diode-uncontrollable rectification circuit, a thyristor rectification circuit, a Vienna rectification circuit and a PWM rectification circuit.

4. The high-reliability high-power case-based medium-voltage direct-current power supply according to claim 1, wherein the DC/DC direct-current voltage regulating circuit is one of a Buck circuit, a Boost circuit, a Buck-Boost circuit, a phase-shifted full-bridge direct-current conversion circuit and a resonant direct-current conversion circuit.

5. The high-reliability high-power case-based medium-voltage direct-current power supply according to claim 2, wherein the bypass circuit is a diode connected in anti-parallel with the output end of the DC/DC voltage regulating circuit.

6. The high reliability high power case based hvdc power supply of claim 2, wherein said bypass circuit comprises a bypass switch in series with said DC/DC voltage regulator circuit, said bypass switch output being anti-parallel connected to a diode.