Three-port bidirectional power converter
阅读说明：本技术 一种三端口双向功率变换器 (Three-port bidirectional power converter ) 是由 石伟 刘中伟 肖正虎 史耀华 于 2020-06-02 设计创作，主要内容包括：本发明公开了一种三端口双向功率变换器,能实现同一回路中能量的双向流动,该变换器包括：三相H桥电路单元、母线电容、第一全桥网络、谐振单元及第二全桥网络；三相H桥电路包括并联连接且跨接于母线电容两端的第一桥臂、第二桥臂、第三桥臂及分别与三个桥臂的中点连接的第一电感、第二电感、第三电感,第一电感和第二电感与第一交流端口连接,第三电感与第二电感与第二交流端口连接,第一全桥网络包括并联连接且跨接于母线电容两端的第四桥臂和第五桥臂；第二全桥网络包括并联连接的第六桥臂和第七桥臂,第六桥臂与第七桥臂并联的两端与直流电源端口连接；谐振单元两端分别与第一全桥网络两个桥臂中点及第二全桥网络两个桥臂中点连接。(The invention discloses a three-port bidirectional power converter, which can realize bidirectional flow of energy in the same loop, and comprises: the three-phase H-bridge circuit comprises a three-phase H-bridge circuit unit, a bus capacitor, a first full-bridge network, a resonance unit and a second full-bridge network; the three-phase H-bridge circuit comprises a first bridge arm, a second bridge arm and a third bridge arm which are connected in parallel and bridged at two ends of a bus capacitor, and a first inductor, a second inductor and a third inductor which are respectively connected with the middle points of the three bridge arms, wherein the first inductor and the second inductor are connected with a first alternating current port, the third inductor and the second inductor are connected with a second alternating current port, and a first full-bridge network comprises a fourth bridge arm and a fifth bridge arm which are connected in parallel and bridged at two ends of the bus capacitor; the second full-bridge network comprises a sixth bridge arm and a seventh bridge arm which are connected in parallel, and two ends of the sixth bridge arm and the seventh bridge arm which are connected in parallel are connected with a direct-current power port; two ends of the resonance unit are respectively connected with the middle points of the two bridge arms of the first full-bridge network and the middle points of the two bridge arms of the second full-bridge network.)
1. A three-port bidirectional power converter is characterized by comprising a three-phase H-bridge circuit unit, a bus capacitor, a first full-bridge network, a resonance unit and a second full-bridge network which are sequentially connected;
the three-phase H-bridge circuit unit comprises a first bridge arm, a second bridge arm, a third bridge arm, a first inductor, a second inductor and a third inductor, the first bridge arm comprises a first switch and a second switch which are connected in series, the second bridge arm comprises a third switch and a fourth switch which are connected in series, the third bridge arm comprises a fifth switch and a sixth switch which are connected in series, the first bridge arm, the second bridge arm and the third bridge arm are connected in parallel and are respectively bridged at two ends of the bus capacitor, the first end of the first inductor is connected with the midpoint of the first bridge arm, the first end of the second inductor is connected with the midpoint of the second bridge arm, the first end of the third inductor is connected with the midpoint of the third bridge arm, the second end of the first inductor and the second end of the second inductor are connected with a first alternating current power supply port, the second end of the third inductor and the second end of the second inductor are connected with a second alternating current power supply port;
the first full-bridge network comprises a fourth bridge arm and a fifth bridge arm, and the fourth bridge arm and the fifth bridge arm are connected in parallel and are respectively bridged at two ends of the bus capacitor;
the second full-bridge network comprises a sixth bridge arm and a seventh bridge arm which are connected in parallel, and two ends of the sixth bridge arm and the seventh bridge arm of the second full-bridge network, which are connected in parallel, are connected with a direct current power port;
the first full-bridge network and the second full-bridge network are synchronously modulated;
the input end of the resonance unit is respectively connected with the midpoint of the fourth bridge arm and the midpoint of the fifth bridge arm, and the output end of the resonance unit is respectively connected with the midpoint of the sixth bridge arm and the midpoint of the seventh bridge arm.
2. The three-port bidirectional power converter of claim 1, wherein said fourth leg comprises a first component and a second component connected in series, and said fifth leg comprises a third component and a fourth component connected in series;
the first assembly, the second assembly, the third assembly and the fourth assembly are all fully-controlled switch assemblies; alternatively, the first and second electrodes may be,
the first assembly and the second assembly are full-control switch assemblies, and the third assembly and the fourth assembly are capacitance elements; alternatively, the first and second electrodes may be,
the first assembly and the second assembly are capacitance elements, and the third assembly and the fourth assembly are full-control switch assemblies; alternatively, the first and second electrodes may be,
the first component and the third component are full-control type switch components, and the second component and the fourth component are two primary windings of the same coupling transformer; alternatively, the first and second electrodes may be,
the first component and the third component are two primary windings of the same coupling transformer, and the second component and the fourth component are full-control switch components;
the full-control type switch assembly comprises a full-control type switch device or comprises the full-control type switch device and a capacitance element which are connected in parallel.
3. The three-port bidirectional power converter of claim 2, wherein said sixth leg comprises a fifth component and a sixth component connected in series, and said seventh leg comprises a seventh component and an eighth component connected in series;
the fifth assembly, the sixth assembly, the seventh assembly and the eighth assembly are all fully-controlled switch assemblies; alternatively, the first and second electrodes may be,
the fifth assembly and the sixth assembly are full-control type switch assemblies, and the seventh assembly and the eighth assembly are capacitance elements; alternatively, the first and second electrodes may be,
the fifth assembly and the sixth assembly are capacitance elements, and the seventh assembly and the eighth assembly are full-control switch assemblies; alternatively, the first and second electrodes may be,
the fifth component and the seventh component are full-control switch components, and the sixth component and the eighth component are two secondary windings of the same coupling transformer; alternatively, the first and second electrodes may be,
the fifth component and the seventh component are two secondary windings of the same coupling transformer, and the sixth component and the eighth component are full-control switch components.
4. The three-port bidirectional power converter according to any of claims 1-3, wherein the resonant unit comprises a first resonant circuit comprising a first resonant inductance when a capacitive element is included in the first full-bridge network and/or the second full-bridge network.
5. The three-port bidirectional power converter according to any of claims 1-3, wherein the resonant unit comprises a first resonant circuit comprising a first resonant inductor and a first resonant capacitor connected in series.
6. The three-port bidirectional power converter according to claim 4 or 5, wherein said resonant unit further comprises an excitation inductor connected across two legs of said first resonant circuit.
7. The three-port bidirectional power converter according to claim 4 or 5, wherein the resonant unit further comprises a transformer, and the first resonant circuit is connected in series to a primary winding of the transformer.
8. The three-port bidirectional power converter of claim 7,
when the first full-bridge network comprises two primary windings of the same coupling transformer, the two primary windings of the same coupling transformer in the first full-bridge network are the primary windings of the transformer in the resonance unit;
when the second full-bridge network comprises two secondary windings of the same coupling transformer, the two secondary windings of the same coupling transformer in the second full-bridge network are the secondary windings of the transformer in the resonance unit.
9. The three-port bidirectional power converter according to claim 7 or 8, wherein the resonant unit further comprises a second resonant circuit connected in series on a secondary winding of a transformer in the resonant unit;
the second resonant circuit comprises a second resonant capacitor and/or a second resonant inductor.
10. The three-port bidirectional power converter of claim 1 further comprising current sampling devices respectively connected in series with said first, second and third inductors.
Technical Field
The invention relates to the technical field of power electronics, in particular to a three-port bidirectional power converter.
Background
In a system with hybrid power supply of alternating current and direct current electric energy sources, the power electronic conversion device is expected to enable energy to flow in two directions at each energy source port like an energy pipeline, and an alternating current and direct current hybrid energy pipeline system is formed. As shown in fig. 1, the schematic diagram of a typical AC/DC hybrid energy pipe system is composed of two AC power ports and a DC power port, where the first AC power port, the second AC power port and the DC power port are respectively coupled to a common DC bus through a first bidirectional AC/
Taking the construction of a bidirectional DC/DC converter in an ac/DC hybrid energy pipeline system as an example, the following methods can be used:
first, as shown in fig. 2a, two independent DC/DC converters are used, and the two DC/DC converters operate independently to respectively realize conversion from a first DC port to a second DC port and conversion from the second DC port to the first DC port;
secondly, as shown in fig. 2b, two independent DC/DC converters are merged to realize sharing of a part of devices, and when energy is converted from the first DC port to the second DC port and from the second DC port to the first DC port, respectively, energy passes through a part of common units or devices, so that the cost of the bidirectional DC-DC converter can be reduced by locally sharing the units or devices. In which, in a very extreme case, only one DC/DC converter is used, and two selection units are used, as shown in fig. 2c, and local sharing is implemented by the selection units, thereby reducing the system cost.
The alternating current-direct current hybrid energy pipeline system applying the two bidirectional DC/DC converters cannot realize bidirectional flow of energy in the same loop in the true sense.
Disclosure of Invention
The invention provides a three-port bidirectional power converter which can realize bidirectional flow of energy in the same loop in the true sense and provide different energy pipelines for an alternating current and direct current hybrid system applying the three-port bidirectional power converter.
The invention provides a three-port bidirectional power converter, comprising: the three-phase H-bridge circuit unit, the bus capacitor, the first full-bridge network, the resonance unit and the second full-bridge network are sequentially connected;
the three-phase H-bridge circuit unit comprises a first bridge arm, a second bridge arm, a third bridge arm, a first inductor, a second inductor and a third inductor, the first bridge arm comprises a first switch and a second switch which are connected in series, the second bridge arm comprises a third switch and a fourth switch which are connected in series, the third bridge arm comprises a fifth switch and a sixth switch which are connected in series, the first bridge arm, the second bridge arm and the third bridge arm are connected in parallel and are respectively bridged at two ends of the bus capacitor, the first end of the first inductor is connected with the midpoint of the first bridge arm, the first end of the second inductor is connected with the midpoint of the second bridge arm, the first end of the third inductor is connected with the midpoint of the third bridge arm, the second end of the first inductor and the second end of the second inductor are connected with a first alternating current power supply port, the second end of the third inductor and the second end of the second inductor are connected with a second alternating current power supply port;
the first full-bridge network comprises a fourth bridge arm and a fifth bridge arm, and the fourth bridge arm and the fifth bridge arm are connected in parallel and are respectively bridged at two ends of the bus capacitor;
the second full-bridge network comprises a sixth bridge arm and a seventh bridge arm which are connected in parallel, and two ends of the sixth bridge arm and the seventh bridge arm of the second full-bridge network, which are connected in parallel, are connected with a direct current power port;
the first full-bridge network and the second full-bridge network are synchronously modulated;
the input end of the resonance unit is respectively connected with the midpoint of the fourth bridge arm and the midpoint of the fifth bridge arm, and the output end of the resonance unit is respectively connected with the midpoint of the sixth bridge arm and the midpoint of the seventh bridge arm.
In a possible embodiment, the fourth leg comprises a first and a second assembly connected in series, and the fifth leg comprises a third and a fourth assembly connected in series;
the first assembly, the second assembly, the third assembly and the fourth assembly are all fully-controlled switch assemblies; alternatively, the first and second electrodes may be,
the first assembly and the second assembly are full-control switch assemblies, and the third assembly and the fourth assembly are capacitance elements; alternatively, the first and second electrodes may be,
the first assembly and the second assembly are capacitance elements, and the third assembly and the fourth assembly are full-control switch assemblies; alternatively, the first and second electrodes may be,
the first component and the third component are full-control type switch components, and the second component and the fourth component are two primary windings of the same coupling transformer; alternatively, the first and second electrodes may be,
the first component and the third component are two primary windings of the same coupling transformer, and the second component and the fourth component are full-control switch components;
the full-control type switch assembly comprises a full-control type switch device or comprises the full-control type switch device and a capacitance element which are connected in parallel.
In a possible embodiment, the sixth leg comprises a fifth assembly and a sixth assembly connected in series, the seventh leg comprises a seventh assembly and an eighth assembly connected in series;
the fifth assembly, the sixth assembly, the seventh assembly and the eighth assembly are all fully-controlled switch assemblies; alternatively, the first and second electrodes may be,
the fifth assembly and the sixth assembly are full-control type switch assemblies, and the seventh assembly and the eighth assembly are capacitance elements; alternatively, the first and second electrodes may be,
the fifth assembly and the sixth assembly are capacitance elements, and the seventh assembly and the eighth assembly are full-control switch assemblies; alternatively, the first and second electrodes may be,
the fifth component and the seventh component are full-control switch components, and the sixth component and the eighth component are two secondary windings of the same coupling transformer; alternatively, the first and second electrodes may be,
the fifth component and the seventh component are two secondary windings of the same coupling transformer, and the sixth component and the eighth component are full-control switch components.
In a possible embodiment, the resonant unit comprises a first resonant circuit comprising a first resonant inductance when a capacitive element is comprised in the first full-bridge network and/or the second full-bridge network.
In a possible embodiment, the resonant unit comprises a first resonant circuit comprising a first resonant inductance and a first resonant capacitance connected in series.
In a possible embodiment, the resonant unit further comprises an excitation inductance connected across the two branches of the first resonant circuit.
In a possible embodiment, the resonant unit further comprises a transformer, and the first resonant circuit is connected in series to a primary winding of the transformer.
In a possible embodiment, when the first full-bridge network includes two primary windings of the same coupling transformer, the two primary windings of the same coupling transformer in the first full-bridge network are the primary windings of the transformer in the resonant unit;
when the second full-bridge network comprises two secondary windings of the same coupling transformer, the two secondary windings of the same coupling transformer in the second full-bridge network are the secondary windings of the transformer in the resonance unit.
In a possible embodiment, the resonant unit further comprises a second resonant circuit connected in series to the secondary winding of the transformer in the resonant unit;
the second resonant circuit comprises a second resonant capacitor and/or a second resonant inductor.
In a possible implementation, the current sampling device is further included, and the current sampling device is respectively connected in series with the first inductor, the second inductor and the third inductor.
The invention has the beneficial effects that: in the three-port bidirectional power converter provided by the embodiment of the present invention, the first inductor and the second inductor are coupled to the first AC power port, the second inductor and the third inductor are coupled to the second AC power port, the second full-bridge network is coupled to the DC power port, the first bridge arm, the first inductor L1, the second bridge arm, and the second inductor L2 form a first bidirectional AC/DC converter, the second bridge arm is a common bridge arm, the second inductor L2, the third bridge arm, and the third inductor L3 form a second bidirectional AC/DC converter, the first full-
Drawings
FIG. 1 is a schematic structural diagram of a hybrid AC/DC energy piping system according to the prior art;
FIGS. 2a, 2b and 2c are schematic diagrams of the structure of a prior art bidirectional DC/DC converter;
fig. 3 is a schematic structural diagram of a three-port bidirectional power converter according to an embodiment of the present invention;
fig. 4a is a schematic structural diagram of a first full-bridge network according to an embodiment of the present invention;
fig. 4b is a schematic structural diagram of a second full-bridge network according to an embodiment of the present invention;
fig. 5a, fig. 5b, fig. 5c, fig. 5d, fig. 5e, fig. 5f, fig. 5g, fig. 5h, fig. 5i and fig. 5j are schematic structural diagrams of a first full-bridge network or a second full-bridge network according to an embodiment of the present invention;
fig. 6a and 6b are schematic structural diagrams of a resonant unit according to an embodiment of the present invention;
fig. 7a and 7b are schematic structural diagrams of a resonant unit according to an embodiment of the present invention;
fig. 8a, 8b and 8c are schematic structural diagrams of a resonant unit according to an embodiment of the present invention;
fig. 9a, 9b, 9c, 9d, 9c, 9e, 9f, 9g, and 9h are schematic structural diagrams of a resonant unit according to an embodiment of the present invention;
fig. 10 is a schematic diagram of a three-port bidirectional power converter according to an embodiment of the present invention;
fig. 11 is a schematic structural diagram of an ac-dc hybrid power supply system according to an embodiment of the present invention;
FIG. 12 is a schematic diagram of another three-port bidirectional power converter according to an embodiment of the present invention;
FIG. 13 is a schematic diagram of another three-port bidirectional power converter according to an embodiment of the present invention;
fig. 14 is a schematic structural diagram of another three-port bidirectional power converter according to an embodiment of the present invention.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
In order to solve the problems in the prior art, embodiments of the present invention provide a three-port bidirectional power converter, which can implement bidirectional flow of energy in the same loop in the true sense, and provide different energy conduits for an ac-dc hybrid power supply system applying the three-port bidirectional power converter.
The three-port bidirectional power converter provided by the embodiment of the invention is described in detail below with reference to the accompanying drawings and specific embodiments.
An embodiment of the present invention provides a three-port bidirectional power converter, as shown in fig. 3, the three-port bidirectional power converter includes: the three-phase H-bridge circuit comprises a three-phase H-
the three-phase H-bridge circuit unit 100 includes a first leg, a second leg, a third leg, a first inductance L1, a second inductor L2 and a third inductor L3, the first bridge arm comprises a first switch S1 and a second switch S2 which are connected in series, the second bridge arm comprises a third switch S3 and a fourth switch S4 which are connected in series, the third bridge arm comprises a fifth switch S5 and a sixth switch S6 which are connected in series, the first bridge arm, the second bridge arm and the third bridge arm are connected in parallel and respectively bridged at two ends of a bus capacitor C, a first end of the first inductor L1 is connected with a midpoint of the first bridge arm, a first end of the second inductor L2 is connected with a midpoint of the second bridge arm, a first end of the third inductor L3 is connected with a midpoint of the third bridge arm, a second end of the first inductor L1 and a second end of the second inductor L2 are connected with a first alternating current power supply port, and a second end of the third inductor L3 and a second end of the second inductor L2 are connected with a second alternating current power supply port; specifically, the midpoint of the first bridge arm is a series connection point of a first switch and a second switch, and the midpoint of the second bridge arm is a series connection point of a third switch and a fourth switch;
the first full-
the second full-
the first full-bridge network and the second full-bridge network are synchronously modulated;
the input end of the
In a specific embodiment, the ac-dc hybrid power supply system employs the three-port bidirectional power converter, specifically, the three-port bidirectional power converter has a second terminal of the first inductor L1 and a second terminal of the second inductor L2 coupled to the first ac power port, a second terminal of the second inductor L2 and a second terminal of the third inductor L3 coupled to the second ac power port, and two parallel-connected terminals of the sixth leg and the seventh leg of the second full-
In the three-port bidirectional power converter provided in the embodiment of the present invention, the three-phase H-bridge circuit unit 100 may form two bidirectional AC/DC converters, specifically, the first bridge arm, the first inductor L1, the second bridge arm, and the second inductor L2 form a first full-bridge rectifier/inverter, the second bridge arm is a common bridge arm, and the third bridge arm, the third inductor L3, the second bridge arm, and the second inductor L2 form a second full-bridge rectifier/inverter; when the three-port bidirectional power converter normally works, the first full-bridge rectifier/inverter and the second full-bridge rectifier/inverter can both adopt a unipolar modulation mode, and can both use the second bridge arm as a power frequency conduction bridge arm; the third switch S3 and the fourth switch S4 are in power frequency complementary conduction to clamp the first end voltage of the second inductor L2 to one end or the other end potential of the bus capacitor C, the first switch S1 and the second switch S2 are also in high-frequency complementary conduction after being modulated according to sine wave signals, and the first full-bridge rectifier/inverter forms a first bidirectional AC/DC converter; meanwhile, the third switch S3 and the fourth switch S4 are in power frequency complementary conduction, one end voltage of the second inductor L2 is clamped to one end or the other end potential of the bus capacitor C, the fifth switch S5 and the sixth switch S6 are modulated according to sine wave signals and then are in high frequency complementary conduction, and the second full-bridge rectifier/inverter forms the second bidirectional AC/DC converter.
In the three-port bidirectional power converter provided in the above-mentioned embodiment of the invention, the first full-bridge network 200, the resonant unit 300, and the second full-bridge network 400 may form a bidirectional DC/DC converter, and specifically, when the first full-bridge network 200 and the second full-bridge network 400 are modulated in a synchronous modulation mode, the first full-bridge network 200 and the second full-bridge network 400 maintain a synchronous on-time within one high-frequency switching period, during the on-time, a DC-side voltage of the first full-bridge network 200 is coupled to an input terminal of the resonant unit 300 to form a voltage V1, a DC-side voltage of the second full-bridge network 400 is coupled to an output terminal of the resonant unit 300 to form a voltage V2, the resonant unit 300 is an inductive element or a combination of an inductive element and a capacitive element, and its high-frequency characteristic shows a certain impedance characteristic, and the voltage V1 and the voltage V2 form a certain voltage difference across the resonant unit 300, the direction of the average current flowing through the resonance unit 300 is determined according to the positive and negative of the voltage difference, and the high-frequency impedance characteristic of the resonance unit 300 can limit the current to rapidly rise so as to avoid the current from being out of control. Therefore, the energy conversion direction of the bidirectional DC/DC converter formed by the first full-