CN-117728675-B - Single-stage three-phase bidirectional converter and vehicle-mounted charging equipment

CN117728675BCN 117728675 BCN117728675 BCN 117728675BCN-117728675-B

Abstract

The application provides a single-stage three-phase bidirectional converter and vehicle-mounted charging equipment. The single-stage three-phase bidirectional converter comprises a single-stage alternating current-direct current conversion module, wherein the single-stage alternating current-direct current conversion module is provided with a first alternating current input port, a second alternating current input port, a third alternating current input port, a fourth alternating current input port, a first direct current port and a second direct current port. According to the technical scheme, the single-stage isolated three-phase bidirectional conversion can be realized on the basis of simplifying a circuit.

Inventors

CHEN LIHONG
HAO SHIQIANG
XU CHENTING

Assignees

浙江富特科技股份有限公司

Dates

Publication Date: 20260505
Application Date: 20231124

Claims (12)

1. A single-stage three-phase bidirectional current transformer, comprising: a single-stage ac-dc conversion module having a first ac input port, a second ac input port, a third ac input port, and first and second dc ports, the single-stage ac-dc conversion module comprising: A first DC-DC converter having a first polarity input port and a second polarity input port and a first polarity output port and a second polarity output port; a second DC-DC converter having a first polarity input port and a second polarity input port and a first polarity output port and a second polarity output port; A third DC-DC converter having a first polarity input port and a second polarity input port and a first polarity output port and a second polarity output port; the first polarity input port of the first DC-DC converter is electrically connected to the first alternating current input port, the first polarity input port of the second DC-DC converter is electrically connected to the second alternating current input port, and the first polarity input port of the third DC-DC converter is electrically connected to the third alternating current input port; The first polarity output port of the first DC-DC converter, the first polarity output port of the second DC-DC converter, and the first polarity output port of the third DC-DC converter are electrically connected to the first DC port, and the second polarity output port of the first DC-DC converter, the second polarity output port of the second DC-DC converter, and the second polarity output port of the third DC-DC converter are electrically connected to the second DC port.
2. The single-stage three-phase bidirectional converter according to claim 1, wherein, The single-stage ac-dc conversion module further has a fourth ac input port, The single-stage alternating current-direct current conversion module further comprises: a fourth DC-DC converter having a first polarity input port and a second polarity input port and a first polarity output port and a second polarity output port; A first polarity input port of the fourth DC-DC converter is electrically connected to the fourth ac input port, and a second polarity input port of the fourth DC-DC converter is electrically connected to the second polarity input port of the first DC-DC converter, the second polarity input port of the second DC-DC converter, and the second polarity input port of the third DC-DC converter; the first polarity output port of the fourth DC-DC converter is electrically connected to the first DC port and the second polarity output port of the fourth DC-DC converter is electrically connected to the second DC port.
3. The single-stage three-phase bidirectional current transformer of claim 1, further comprising: the alternating current side filtering module is electrically connected between an alternating current power supply and the single-stage alternating current-direct current conversion module, wherein the alternating current side filtering module shares a half-bridge capacitor of the single-stage alternating current-direct current conversion module.
4. The single-stage three-phase bidirectional current transformer of claim 1, further comprising: and the direct current side filter is electrically connected between the first direct current port and the second direct current port.
5. A single-stage three-phase bidirectional converter according to claim 2, wherein, The first DC-DC converter includes a first isolation transformer; the second DC-DC converter includes a second isolation transformer; the third DC-DC converter includes a third isolation transformer; the fourth DC-DC converter includes a fourth isolation transformer; the first isolation transformer, the second isolation transformer, the third isolation transformer and the fourth isolation transformer share a secondary side or the secondary side is independent.
6. The single-stage three-phase bidirectional converter according to claim 5, wherein the first, second, third and fourth isolation transformers are high frequency isolation transformers.
7. The single-stage three-phase bidirectional converter according to claim 2, wherein the first, second, third, and fourth DC-DC converters transfer energy back in an intermittent manner, each DC-DC converter being shorted to a primary side so as not to transfer energy to a secondary side when a voltage difference between the first and second polarity input ports thereof is 0.
8. A single-stage three-phase bidirectional converter according to claim 2, wherein, When θ=0, the first DC-DC converter operates in a DC-DC mode, the second DC-DC converter operates in a DC-DC mode, the third DC-DC converter is in a short-circuit mode, and the fourth DC-DC converter operates in a DC-DC mode; when θ=120°, the first DC-DC converter is in a short-circuit mode, the second DC-DC converter is operated in a DC-DC mode, the third DC-DC converter is operated in a DC-DC mode, and the fourth DC-DC converter is operated in a DC-DC mode; when θ=240°, the first DC-DC converter operates in a DC-DC mode, the second DC-DC converter is in a short-circuit mode, the third DC-DC converter operates in a DC-DC mode, and the fourth DC-DC converter operates in a DC-DC mode.
9. The single-stage three-phase bidirectional converter according to claim 8, wherein, Shorting the first polarity input port and the second polarity input port of the third DC-DC converter at 0 ° to 120 ° of the three-phase alternating voltage signal period; Shorting the first polarity input port and the second polarity input port of the first DC-DC converter at 120 ° to 240 ° of the three-phase alternating voltage signal period; The first polarity input port and the second polarity input port of the second DC-DC converter are shorted at 240 ° to 360 ° of the three-phase alternating voltage signal period.
10. The single-stage three-phase bidirectional converter according to claim 1, wherein the first polarity input port is a positive or negative input port and the second polarity input port is a negative or positive input port, respectively.
11. A single-stage three-phase bidirectional converter according to claim 2, wherein, The first DC-DC converter comprises a half-bridge circuit formed by a first switching element, a second switching element, a first capacitor and a second capacitor and a first isolation transformer, wherein: the first switch element is provided with a first end, a second end and a control end, and the control end controls the first switch element to be turned on or turned off; the second switch element is provided with a first end, a second end and a control end, and the control end controls the second switch element to be turned on or turned off; the second switching element is connected in series with the first switching element between the first polarity input port and the second polarity input port of the first DC-DC converter, and the first capacitor is connected in series with the second capacitor between the first polarity input port and the second polarity input port of the first DC-DC converter; The primary winding of the first isolation transformer is connected between a series node between the second switching element and the first switching element and a series node between the first capacitor and the second capacitor; The second DC-DC converter comprises a half-bridge circuit formed by a third switching element, a fourth switching element, a third capacitor and a fourth capacitor and a second isolation transformer, wherein: the third switching element is provided with a first end, a second end and a control end, and the control end controls the third switching element to be turned on or turned off; The fourth switching element is provided with a first end, a second end and a control end, and the control end controls the fourth switching element to be turned on or turned off; The third switching element and the fourth switching element are connected in series between the first polarity input port and the second polarity input port of the second DC-DC converter, and the third capacitor and the fourth capacitor are connected in series between the first polarity input port and the second polarity input port of the second DC-DC converter; The primary winding of the second isolation transformer is connected between a series node between the third switching element and the fourth switching element and a series node between the third capacitor and the fourth capacitor; The third DC-DC converter comprises a half-bridge circuit formed by a fifth switching element, a sixth switching element, a fifth capacitor and a sixth capacitor and a third isolation transformer, wherein: the fifth switching element is provided with a first end, a second end and a control end, and the control end controls the fifth switching element to be turned on or turned off; the sixth switching element is provided with a first end, a second end and a control end, and the control end controls the sixth switching element to be turned on or turned off; The fifth switching element and the sixth switching element are connected in series between the first polarity input port and the second polarity input port of the third DC-DC converter, and the fifth capacitor and the sixth capacitor are connected in series between the first polarity input port and the second polarity input port of the third DC-DC converter; A primary winding of the third isolation transformer is connected between a series node between the fifth switching element and the sixth switching element and a series node between the fifth capacitor and the sixth capacitor; The fourth DC-DC converter comprises a half-bridge circuit formed by a seventh switching element, an eighth switching element, a seventh capacitor and an eighth capacitor and a fourth isolation transformer, wherein: The seventh switching element is provided with a first end, a second end and a control end, and the control end controls the seventh switching element to be turned on or turned off; the eighth switching element is provided with a first end, a second end and a control end, and the control end controls the eighth switching element to be turned on or turned off; the seventh switching element and the eighth switching element are connected in series between the first polarity input port and the second polarity input port of the fourth DC-DC converter, and the seventh capacitor and the eighth capacitor are connected in series between the first polarity input port and the second polarity input port of the fourth DC-DC converter; A primary winding of the fourth isolation transformer is connected between a series node between the seventh switching element and the eighth switching element and a series node between the seventh capacitor and the eighth capacitor; The first isolation transformer, the second isolation transformer, the third isolation transformer, and the fourth isolation transformer share a secondary winding.
12. A vehicle-mounted charging apparatus comprising a single-stage three-phase bidirectional converter according to any one of claims 1 to 11.

Description

Single-stage three-phase bidirectional converter and vehicle-mounted charging equipment Technical Field The invention relates to the technical field of power electronics, in particular to a single-stage three-phase bidirectional converter. Background Currently, resource shortage and environmental pollution become two major problems impeding human development, and new energy must be researched and developed in order to solve the energy problem. The three-phase AC/DC bi-directional converter is a current transformer capable of converting three-phase AC power into DC power or from DC power into three-phase AC power, which is a current transformer of single-stage type, has become a hot research subject. It is typically composed of a plurality of three-phase bridge inverters, each coupled between them by a capacitor or inductor. The single-stage three-phase bidirectional converter has the advantages of simple structure and low cost, but has the disadvantages of low efficiency and low power factor, and needs to use a larger capacitor or inductor for coupling. Compared with the back-to-back bidirectional converter, the three-phase AC/DC bidirectional converter has the topological structure which is only half of that of the back-to-back bidirectional converter, but can realize the same function, namely, the bidirectional flow of energy. The three-phase AC/DC bidirectional converter can realize bidirectional energy transmission, and has wide application in the fields of motor control, automobile electronics, new energy power generation and the like. The traditional full-bridge circuit works in a rectification mode as a three-phase Boost type PWM rectifier, bus voltage can only rise and cannot fall, interaction with an energy storage system is usually achieved through a two-stage circuit, and the matrix type bidirectional converter works in the rectification mode as a three-phase Buck type PWM rectifier, and although the matrix type converter can achieve single-stage charging, compared with a traditional full-bridge type topological structure, the number of switching tubes on a main bridge arm is doubled, and control is relatively complex. Therefore, a technical scheme is needed, and the circuit can be simplified on the premise of ensuring the power density. Disclosure of Invention The application aims to provide a single-stage three-phase bidirectional converter, which can simplify a circuit and realize single-stage isolated three-phase bidirectional conversion on the premise of ensuring power density through the design of the circuit scheme. According to an aspect of the present application, there is provided a single-stage three-phase bidirectional converter including: Single-stage ac/dc conversion module having The individual entities correspond. That is, these functional entities may be implemented in software, or have a first ac input port, a second ac input port, a third ac input port, and a first dc port and a second dc port, and the single-stage ac-dc conversion module includes: A first DC-DC converter having a first polarity input port and a second polarity input port and a first polarity output port and a second polarity output port; a second DC-DC converter having a first polarity input port and a second polarity input port and a first polarity output port and a second polarity output port; A third DC-DC converter having a first polarity input port and a second polarity input port and a first polarity output port and a second polarity output port; The first polarity input port of the first DC-DC converter is electrically connected to the first alternating current input port, the first polarity input port of the second DC-DC converter is electrically connected to the second alternating current input port, and the first polarity input port of the third DC-DC converter is electrically connected to the third alternating current input port alternating current input; The first polarity output port of the first DC-DC converter, the first polarity output port of the second DC-DC converter, and the first polarity output port of the third DC-DC converter are electrically connected to the first DC port, and the second polarity output port of the first DC-DC converter, the second polarity output port of the second DC-DC converter, and the second polarity output port of the third DC-DC converter are electrically connected to the second DC port. According to some embodiments, the single stage ac-dc conversion module further has a fourth ac input port, the single stage ac-dc conversion module further comprising: a fourth DC-DC converter having a first polarity input port and a second polarity input port and a first polarity output port and a second polarity output port; A first polarity input port of the fourth DC-DC converter is electrically connected to the fourth ac input port, and a second polarity input port of the fourth DC-DC converter is electrically connected to the second polarity input port of the first DC-DC