CN111559266A

CN111559266A - Charging device for electric automobile

Info

Publication number: CN111559266A
Application number: CN202010520766.8A
Authority: CN
Inventors: 徐坤山; 臧凤启; 黄家才; 曾元静; 李本元; 盛云龙; 赵贤林; 史建军; 黄亚洲
Original assignee: Nanjing Institute of Technology
Current assignee: Nanjing Institute of Technology
Priority date: 2020-06-10
Filing date: 2020-06-10
Publication date: 2020-08-21
Anticipated expiration: 2040-06-10
Also published as: CN111559266B

Abstract

The invention discloses an electric automobile charging device which comprises a hybrid modular multilevel converter, a matrix switch and a plurality of charging piles, wherein the hybrid modular multilevel converter, the matrix switch and the charging piles are sequentially connected, and the input end of the hybrid modular multilevel converter is connected with a power supply. According to the invention, the mixed modular multilevel converter at the front end is adopted, so that the transformer is saved, the voltage adjustment range of the direct current bus is wider, the capacity expansion is facilitated, and the flexibility of a power supply system is improved by adding the matrix switch.

Description

Charging device for electric automobile

Technical Field

The invention belongs to the technical field of terminals, and particularly relates to an electric automobile charging device.

Background

Along with the rapid increase of the number of electric automobiles, the demand of charging piles is increasingly vigorous. The existing high-power charging pile power supply structure mainly has two structures: one is 380V three-phase rectification at the front end, an isolation DCDC converter at the rear end, and then the isolation DCDC converter is used as a module for parallel capacity expansion; one is 10kV input, the voltage is reduced by a transformer, then the voltage is rectified into high-voltage direct current, usually 800V to 1000V, the high-voltage direct current is taken as a bus, and a plurality of DC/DC converters are connected in series at the rear end to charge the electric automobile. The former structure has the problem that when the power supply is high, the input current is too high, the requirement on a cable is too high, and therefore the power supply of the structure is limited. The latter structure can be applied to high-power occasions, but the structure has a large-capacity transformer, so that the efficiency is low, the expansion is not easy, the redundancy is low, and the flexibility is poor.

Disclosure of Invention

Aiming at the defects in the prior art, the invention provides the electric automobile charging device, which enhances the applicability of an electric automobile power supply system, saves a transformer and has strong expansibility.

In order to achieve the purpose, the invention adopts the following technical scheme:

the utility model provides an electric automobile charging device, fills electric pile including the many level converter of hybrid module ization, matrix switch and a plurality of that connect gradually, the input of the many level converter of hybrid module ization is connected with the power.

In order to optimize the technical scheme, the specific measures adopted further comprise:

further, the hybrid modular multilevel converter comprises a plurality of bridge arms, each of which comprises M half-bridge sub-modules and N full-bridge sub-modules, wherein M and N are natural numbers.

Furthermore, the circuit of the charging pile comprises a plurality of isolation DC/DC converters, the input ends of the isolation DC/DC converters are connected in series, and the output ends of the isolation DC/DC converters are connected in parallel.

Furthermore, the matrix switch comprises a plurality of switch units, the switch units are arranged in a matrix form, each switch unit comprises four bidirectional switches which are connected in series to form a loop, and the adjacent switch units share one bidirectional switch.

Furthermore, each corner point in the matrix switch is provided with a connection port, the output end of the connection port is connected with the input end of the charging pile circuit through a switch bus, the input end of the connection port on one side of the matrix switch is connected with the positive pole of the direct-current bus, and the input end of the connection port on the other side of the matrix switch is connected with the negative pole of the direct-current bus through a bidirectional switch.

The invention has the beneficial effects that:

the electric vehicle charging device provided by the invention saves transformers through the front-end hybrid modular multilevel converter, has a wider direct-current bus voltage adjustment range, is beneficial to capacity expansion, and improves the flexibility of a power supply system by adding the matrix switch.

Drawings

Fig. 1 is a schematic structural diagram of an electric vehicle charging device according to the present invention.

Fig. 2 is a schematic diagram of a matrix switch structure according to the present invention.

Detailed Description

The invention will now be described in further detail with reference to the accompanying figures 1-2.

It should be noted that the terms "upper", "lower", "left", "right", "front", "back", etc. used in the present invention are for clarity of description only, and are not intended to limit the scope of the present invention, and the relative relationship between the terms and the terms is not limited by the technical contents of the essential changes.

As shown in fig. 1, in one embodiment of the present invention, an electric vehicle charging apparatus includes a hybrid modular multilevel converter, a matrix switch, and a plurality of charging piles, which are connected in sequence, wherein an input terminal of the hybrid modular multilevel converter is connected to a power supply.

The hybrid modular multilevel converter comprises a plurality of bridge arms, wherein each bridge arm comprises M half-bridge sub-modules and N full-bridge sub-modules, and M and N are natural numbers.

In this embodiment, both M and N are greater than 10, which ensures the adjustment range of the dc bus voltage and is beneficial to capacity expansion.

As shown in fig. 1 and fig. 2, in one embodiment of the present invention, the matrix switch includes a plurality of switch units, a plurality of the switch units are arranged in a matrix, each of the switch units includes four bidirectional switches connected in series to form a loop, and one bidirectional switch is shared between adjacent switch units.

Taking the switch unit 1 as an example, the four bidirectional switches are respectively SY₁₁、SY₂₁、SZ₁₁And SZ₁₂Wherein, SY₁₁、SY₂₁、SZ₁₁And SZ₁₂Are connected in series in sequence, and SZ₁₂And one end of (A) and SY₁₁The system has higher structural redundancy and strong expansibility, and adopts a two-stage transformation structure, thereby having high efficiency.

Each corner in the matrix switch is provided with a connection port, the output end of the connection port is connected with the input end of the isolation DC/DC converter through a switch bus, wherein the isolation DC/DC converter is connected with the mixed MMC through the matrix switch in a switch bus form, for example, a switch bus i is used, and the line number is S_i1To S_ij. The input end of the connection port on one side of the matrix switch is connected with the positive pole of the direct current bus, and the input end of the connection port on the other side of the matrix switch is connected with the negative pole of the direct current bus through a bidirectional switch, as shown in fig. 2, namely S₁₁To S_i1SY connected to the positive pole of the DC bus_1jTo SY_ijAnd is connected with the negative electrode of the direct current bus.

The circuit of the charging pile comprises a plurality of isolation DC/DC converters, the input ends of the isolation DC/DC converters are connected in series, and the output ends of the isolation DC/DC converters are connected in parallel.

In this embodiment, a switch T is connected in series between each isolated DC/DC converter and the connection port_ijSwitch T_ijThe control circuit is used for controlling the on-off of an isolation DC/DC converter connected with the control circuit in series.

In this embodiment, the bidirectional switch in the matrix switch is normally open, and when it is necessary to stop using a certain isolated DC/DC converter, the isolated DC/DC converter can be short-circuited only by closing the bidirectional switch beside the connection port corresponding to the isolated DC/DC converter, for example, when the connection port S needs to be stopped₁₁T can be directly disconnected when corresponding to the isolated DC/DC converter_i1The two-way switch SY can also be used₁₁Closing, or switching, the bidirectional switch SZ₁₁And SZ₁₂And meanwhile, the effect of stopping the isolated DC/DC converter can be realized by closing the system, the flexibility of the power supply system is improved, similarly, when a certain isolated DC/DC converter needs to be used, the corresponding bidirectional switch is disconnected, or the addition of a matrix switch improves the flexibility and the redundancy of the power supply system, and the addition of a hybrid MMC improves the expansibility of the charging system, so that the application range of the system is wide, and the applicability is greatly improved.

The above is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above-mentioned embodiments, and all technical solutions belonging to the idea of the present invention belong to the protection scope of the present invention. It should be noted that modifications and embellishments within the scope of the invention may be made by those skilled in the art without departing from the principle of the invention.

Claims

1. The utility model provides an electric automobile charging device, its characterized in that fills electric pile including the many level converter of hybrid module ization, matrix switch and a plurality of that connect gradually, the input and the power of the many level converter of hybrid module ization are connected.

2. The electric vehicle charging apparatus of claim 1, wherein the hybrid modular multilevel converter comprises a plurality of bridge arms, each of the bridge arms comprising M half-bridge sub-modules and N full-bridge sub-modules, wherein M and N are natural numbers.

3. The electric vehicle charging device of claim 1, wherein the circuit of the charging post comprises a plurality of isolated DC/DC converters, wherein the input terminals of the plurality of isolated DC/DC converters are connected in series, and the output terminals of the plurality of isolated DC/DC converters are connected in parallel.

4. The electric vehicle charging device of claim 3, wherein the matrix switch comprises a plurality of switch units, the plurality of switch units are arranged in a matrix, each switch unit comprises four bidirectional switches connected in series to form a loop, and one bidirectional switch is shared between adjacent switch units.

5. The electric vehicle charging device according to claim 4, wherein a connection port is provided at each corner in the matrix switch, an output end of the connection port is connected to an input end of the charging pile circuit through a switch bus, an input end of the connection port on one side of the matrix switch is connected to a positive electrode of the dc bus, and an input end of the connection port on the other side of the matrix switch is connected to a negative electrode of the dc bus through a bidirectional switch.