阅读说明：本技术 电力电子变压器的控制架构及其控制方法 (Control architecture and control method of power electronic transformer ) 是由 杨晨 张中锋 谢晔源 魏星 葛健 祁琦 王宇 李海英 于 2020-05-26 设计创作，主要内容包括：本申请提供电力电子变压器的控制架构及其控制方法。所述控制架构包括上层控制器、M个子模块单元和通信线路,M为大于等于1的自然数,所述上层控制器包括至少一个控制器通信端口；每个所述子模块单元包括至少两个子模块功率电路和至少一个隔离元件,所述子模块功率电路包括子模块控制器和交直变换器,所述子模块控制器包括至少一个子模块通信端口；所述交直变换器包括至少一个交流端口和至少一个直流端口；所述隔离元件包括至少两个隔离端口,所述隔离端口连接所述交直变换器的交流端口；所述通信线路连接所述上层控制器与所述子模块控制器,或连接不同子模块单元的所述子模块控制器,或连接同一子模块单元的不同的所述子模块控制器。(The application provides a control architecture of a power electronic transformer and a control method thereof. The control architecture comprises an upper-layer controller, M sub-module units and a communication line, wherein M is a natural number greater than or equal to 1, and the upper-layer controller comprises at least one controller communication port; each submodule unit comprises at least two submodule power circuits and at least one isolation element, each submodule power circuit comprises a submodule controller and an alternating current-direct current converter, and each submodule controller comprises at least one submodule communication port; the AC-DC converter comprises at least one AC port and at least one DC port; the isolation element comprises at least two isolation ports, and the isolation ports are connected with alternating current ports of the alternating current-direct current converter; the communication line is connected with the upper layer controller and the sub-module controller, or connected with the sub-module controllers of different sub-module units, or connected with different sub-module controllers of the same sub-module unit.)

1. A control architecture for a power electronic transformer, comprising:

an upper level controller including at least one controller communication port;

m submodule units, M is a natural number more than or equal to 1, each submodule unit comprises:

at least two sub-module power circuits, the sub-module power circuits comprising:

a sub-module controller comprising at least one sub-module communication port;

an AC-DC converter comprising at least one AC port and at least one DC port;

at least one isolation element, wherein the isolation element comprises at least two isolation ports, and the isolation ports are connected with alternating current ports of the alternating current-direct current converter;

and the communication line is connected with the upper layer controller and the sub-module controller, or connected with the sub-module controllers of different sub-module units, or connected with different sub-module controllers of the same sub-module unit.

2. The control architecture of claim 1, wherein the communication line comprises at least one of an a-type connection, a B-type connection, a C-type connection, a D-type connection, an E-type connection, and an F-type connection.

3. The control architecture of claim 2, wherein the type a connection is:

the upper layer controller includes: at least 2M controller communication ports, wherein every two controller communication ports correspond to one sub-module unit;

each of the sub-module units comprises a first sub-module power circuit and a second sub-module power circuit, wherein,

the first sub-module power circuit comprises:

a first submodule controller comprising at least one first submodule communication port; the second sub-module power circuit comprises:

a second submodule controller comprising at least one second submodule communication port;

the two controller communication ports are respectively connected with the first sub-module communication port and the second sub-module communication port through the communication lines.

4. The control architecture of claim 2, wherein the type B connection is:

the upper layer controller includes: at least M controller communication ports, each controller communication port corresponding to one of the sub-module units;

each of the sub-module units comprises a first sub-module power circuit and a second sub-module power circuit, wherein,

the first sub-module power circuit comprises:

the first submodule controller comprises at least two first submodule communication ports; the second sub-module power circuit comprises:

a second submodule controller comprising at least one second submodule communication port;

each controller communication port is connected with one first submodule communication port corresponding to the submodule unit through the communication line, and the other first submodule communication port is connected with the second submodule communication port.

5. The control architecture of claim 2, wherein the type C connection is:

the upper layer controller includes: at least M controller communication ports, each controller communication port corresponding to one of the sub-module units;

each of the sub-module units comprises a first sub-module power circuit and a second sub-module power circuit, wherein,

the first sub-module power circuit comprises:

a first submodule controller comprising at least one first submodule communication port;

the second sub-module power circuit comprises:

the second submodule controller comprises at least two second submodule communication ports;

each controller communication port is connected with one second submodule communication port corresponding to the submodule unit through the communication line, and the other second submodule communication port is connected with the first submodule communication port.

6. The control architecture of claim 2, wherein the D-type connection is:

the upper layer controller includes: at least 2M controller communication ports, wherein every two controller communication ports correspond to one sub-module unit;

each of the sub-module units comprises a first sub-module power circuit and a second sub-module power circuit, wherein,

the first sub-module power circuit comprises:

the first submodule controller comprises at least two first submodule communication ports;

the second sub-module power circuit comprises:

the second submodule controller comprises at least two second submodule communication ports;

one controller communication port of the upper-layer controller is connected with a first sub-module communication port corresponding to the sub-module unit through the communication line, the other controller communication port of the upper-layer controller is connected with one second sub-module communication port through the communication line, and the other first sub-module communication port is connected with the other second sub-module communication port.

7. The control architecture of claim 2, wherein the E-type connection is:

the upper layer controller includes: at least one controller communication port, each controller communication port corresponding to one of the sub-module units;

each sub-module unit comprises a first sub-module power circuit, a second sub-module power circuit, a third communication port and a fourth communication port; wherein the content of the first and second substances,

the first sub-module power circuit comprises:

a first submodule controller comprising at least one first submodule communication port;

the second sub-module power circuit comprises:

a second submodule controller comprising at least one second submodule communication port;

the first sub-module communication port is connected with the second sub-module communication port through the communication line;

and each controller communication interface is connected with the third communication port of any one sub-module unit through the communication line, and the fourth communication port of the sub-module unit is connected with the third communication port of another sub-module unit until all the sub-module units have communication lines.

8. The control architecture of claim 2, wherein the F-type connection is:

the M sub-module units include: the system comprises an x group of submodule units and a y group of submodule units, wherein x and y are positive integers which are more than or equal to 1, and x + y is equal to M;

the upper layer controller includes: at least 1+ y controller communication ports; wherein the content of the first and second substances,

the x sub-module units and a controller communication port form the E-type connection mode;

and the y sub-module units and the rest controller communication ports form at least one of the A-type connection mode, the B-type connection mode, the C-type connection mode and the D-type connection mode.

9. The control architecture of claim 1 wherein all of the ac-to-dc converters comprise a full bridge circuit.

10. The control architecture of claim 9, wherein two full bridges of the two ac-dc converters of the sub-module unit include a pair of corresponding bridge arms on either side, there being an adjustable drive pulse phase shift angle.

11. The control architecture of claim 9, wherein a phase shift angle of the drive pulse exists between the two legs of each full bridge circuit of the two ac-dc converters of the sub-module unit.

12. A method of controlling a power electronic transformer control architecture according to any one of claims 1 to 11, comprising:

the upper-layer controller acquires direct-current voltage information of the sub-module power circuit alternating-current direct-current converter uploaded by each sub-module controller through a communication line, wherein the direct-current voltage information of the sub-module power circuit alternating-current direct-current converter comprises a first direct-current port voltage U1 of a full bridge circuit of a first sub-module controller and a second direct-current port voltage U2 of a full bridge circuit of a second sub-module controller;

determining drive pulses for all AC-DC converters based on the first DC port voltage U1 and the second DC port voltage U2.

13. The control method according to claim 12, wherein the determining the driving pulses of all the ac-dc converters when the communication line is an a-type connection, a B-type connection, a C-type connection, or a D-type connection includes:

determining a first voltage average U1av of the first DC port voltage U1 and a second voltage average U2av of the second DC port voltage U2 for M sub-module cells;

obtaining adjustable driving pulse phase shift angles fi of corresponding bridge arms at two sides of the first full-bridge circuit and the second full-bridge circuit through closed-loop control according to the first voltage average value U1av, the second voltage average value U2av and a set closed-loop reference voltage;

determining a first driving pulse phase shift angle fip and a second driving pulse phase shift angle fis according to the ratio of the first voltage average value U1av and the second voltage average value U2av and the adjustable driving pulse phase shift angle fi, the first driving pulse phase shift angle being a driving pulse phase shift angle fip existing between the two legs of the first full-bridge circuit, the second driving pulse phase shift angle being a driving pulse phase shift angle fis existing between the two legs of the second full-bridge circuit;

and the first voltage average value U1av, the first driving pulse phase shift angle fip and the adjustable driving pulse phase shift angle fi are issued to the first sub-module controller through a communication route, and the second voltage average value U2av, the second driving pulse phase shift angle fis and the adjustable driving pulse phase shift angle fi are issued to the second sub-module controller, so that the first sub-module controller or/and the second sub-module controller determine the driving pulse of the first full-bridge circuit or/and the driving pulse of the second full-bridge circuit.

14. The control method of claim 13, wherein the first or/and second sub-module controller determining drive pulses for a first full-bridge circuit or/and drive pulses for a second full-bridge circuit comprises:

the first sub-module controller or/and the second sub-module controller is/are provided with a reference PWM pulse width;

and obtaining the driving pulse of the first full-bridge circuit or/and the driving pulse of the second full-bridge circuit through the synchronization of an upper layer controller and the respective phase shift according to the adjustable driving pulse phase shift angle fi, the first driving pulse phase shift angle fip and the second driving pulse phase shift angle fis.

15. The control method according to claim 12, wherein the determining the driving pulses of all the ac-dc converters when the communication line is in the E-type connection includes:

determining a first voltage average U1av of the first DC port voltage U1 and a second voltage average U2av of the second DC port voltage U2 for M sub-module cells;

obtaining adjustable driving pulse phase shift angles fi of corresponding bridge arms at two sides of the first full-bridge circuit and the second full-bridge circuit through closed-loop control according to the first voltage average value U1av, the second voltage average value U2av and a set closed-loop reference voltage;

and transmitting the first voltage average value U1av, the second voltage average value U2av and the adjustable driving pulse phase shift angle fi to the sub-module controllers of all the sub-module units through a chain communication loop, so that the first sub-module controller or/and the second sub-module controller determine the driving pulse of the first full-bridge circuit or/and the driving pulse of the second full-bridge circuit.

16. The control method of claim 15, wherein the first or/and second sub-module controller determining drive pulses for a first full-bridge circuit or/and drive pulses for a second full-bridge circuit comprises:

the first sub-module controller and the second sub-module controller simultaneously determine a first driving pulse phase shift angle and a second driving pulse phase shift angle according to the ratio of the first voltage average value U1av or the second voltage average value U2av and the adjustable driving pulse phase shift angle fi, wherein the first driving pulse phase shift angle is a driving pulse phase shift angle fip existing between two bridge arms of the first full-bridge circuit, and the second driving pulse phase shift angle is a driving pulse phase shift angle fis existing between two bridge arms of the second full-bridge circuit;

the first sub-module controller or/and the second sub-module controller are provided with reference PWM pulse width, keep synchronization through a communication line, and respectively shift the phase according to the adjustable driving pulse phase shift angle fi, the first driving pulse phase shift angle fip and the second driving pulse phase shift angle fis to obtain the driving pulse of the first full-bridge circuit or/and the driving pulse of the second full-bridge circuit.

17. The control method according to claim 12, wherein the determining the driving pulses of all the ac-dc converters when the communication line is in an F-type connection includes:

the sub-module units of the x parts determine the driving pulses of all the AC-DC converters by adopting a control mode corresponding to the E-type connection mode of the communication line;

and the sub-module units of the part y determine the driving pulses of all the AC-DC converters by adopting a control mode corresponding to the communication line, namely an A-type connection mode, a B-type connection mode, a C-type connection mode or a D-type connection mode.

Technical Field

The application relates to the technical field of power electronic application, in particular to a control framework of a power electronic transformer and a control method thereof.

Background

The power electronic transformer is a device for realizing electric energy conversion by adopting a power electronic technology, and can realize conversion from medium/high voltage alternating current to low voltage direct current and conversion from medium/high voltage direct current to low voltage direct current according to different circuit topologies. Compare traditional power frequency transformer, through using power electronics technique, isolation transformer link in the circuit can reduce volume and weight through switching frequency's improvement to reduce the copper-iron rate of utilization.

On the other hand, under the influence of the stress and the cost of the switching tube device, the power electronic transformer applied in the type is mostly realized by adopting a structure that a plurality of sub-modules are connected in series and output in parallel, namely an ISOP structure. These sub-modules are typically implemented using a dual active bridge architecture (DAB) based circuit.

The DAB circuit has a basic electrical isolation function, can better realize voltage stability control due to the adoption of closed-loop control, and is a common type selection topology of the conventional ISOP structure power electronic transformer. However, when dealing with the phase-shifted pulse driving of the H-bridge circuit, a more complicated control strategy is required to implement the soft switching function of all the switching devices or to widen the soft switching range.

In order to popularize and apply the power electronic transformer with the ISOP structure formed by the DAB circuit, the requirements of electrical isolation of the DAB circuit and realization of a complex soft switching technology need to be considered when the circuit structure is realized. However, in the existing medium-high voltage application devices, such as flexible-direct MMC circuits or SVG devices, generally, only one optical fiber is connected to an upper controller in one module, and this control architecture cannot be directly applied to an ISOP structure power electronic transformer formed based on a DAB circuit, which may cause that the DAB circuit cannot realize an electrical isolation function or cannot realize a complex soft switching technology.

Disclosure of Invention

The embodiment of the application provides a control architecture of a power electronic transformer, which comprises an upper-layer controller, M sub-module units and a communication line, wherein M is a natural number greater than or equal to 1, and the upper-layer controller comprises at least one controller communication port; each submodule unit comprises at least two submodule power circuits and at least one isolation element, each submodule power circuit comprises a submodule controller and an alternating current-direct current converter, and each submodule controller comprises at least one submodule communication port; the AC-DC converter comprises at least one AC port and at least one DC port; the isolation element comprises at least two isolation ports, and the isolation ports are connected with alternating current ports of the alternating current-direct current converter; the communication line is connected with the upper layer controller and the sub-module controller, or connected with the sub-module controllers of different sub-module units, or connected with different sub-module controllers of the same sub-module unit.

According to some embodiments, the communication line includes at least one of an a-type connection, a B-type connection, a C-type connection, a D-type connection, an E-type connection, and an F-type connection.

According to some embodiments, the type a connection is: the upper-layer controller comprises at least 2M controller communication ports, and every two controller communication ports correspond to one sub-module unit; each submodule unit comprises a first submodule power circuit and a second submodule power circuit, wherein the first submodule power circuit comprises a first submodule controller, and the first submodule controller comprises at least one first submodule communication port; the second sub-module power circuit comprises a second sub-module controller comprising at least one second sub-module communication port; the two controller communication ports are respectively connected with the first sub-module communication port and the second sub-module communication port through the communication lines.

According to some embodiments, the type B connection is: the upper-layer controller comprises at least M controller communication ports, and each controller communication port corresponds to one sub-module unit; each submodule unit comprises a first submodule power circuit and a second submodule power circuit, wherein the first submodule power circuit comprises a first submodule controller, and the first submodule controller comprises at least two first submodule communication ports; the second sub-module power circuit comprises a second sub-module controller comprising at least one second sub-module communication port; each controller communication port is connected with one first submodule communication port corresponding to the submodule unit through the communication line, and the other first submodule communication port is connected with the second submodule communication port.

According to some embodiments, the C-type connection is: the upper-layer controller comprises at least M controller communication ports, and each controller communication port corresponds to one sub-module unit; each submodule unit comprises a first submodule power circuit and a second submodule power circuit, wherein the first submodule power circuit comprises a first submodule controller, and the first submodule controller comprises at least one first submodule communication port; the second sub-module power circuit comprises a second sub-module controller, the second sub-module controller comprising at least two second sub-module communication ports; each controller communication port is connected with one second submodule communication port corresponding to the submodule unit through the communication line, and the other second submodule communication port is connected with the first submodule communication port.

According to some embodiments, the D-type connection is: the upper-layer controller comprises at least 2M controller communication ports, and every two controller communication ports correspond to one sub-module unit; each submodule unit comprises a first submodule power circuit and a second submodule power circuit, wherein the first submodule power circuit comprises a first submodule controller, and the first submodule controller comprises at least two first submodule communication ports; the second sub-module power circuit comprises a second sub-module controller, the second sub-module controller comprising at least two second sub-module communication ports; one controller communication port of the upper-layer controller is connected with a first sub-module communication port corresponding to the sub-module unit through the communication line, the other controller communication port of the upper-layer controller is connected with one second sub-module communication port through the communication line, and the other first sub-module communication port is connected with the other second sub-module communication port.

According to some embodiments, the E-type connection is: the upper-layer controller comprises at least one controller communication port, and each controller communication port corresponds to one sub-module unit; each sub-module unit comprises a first sub-module power circuit, a second sub-module power circuit, a third communication port and a fourth communication port, wherein the first sub-module power circuit comprises a first sub-module controller, and the first sub-module controller comprises at least one first sub-module communication port; wherein the second sub-module power circuit comprises a second sub-module controller comprising at least one second sub-module communication port; the first sub-module communication port is connected with the second sub-module communication port through the communication line; and each controller communication interface is connected with the third communication port of any one sub-module unit through the communication line, and the fourth communication port of the sub-module unit is connected with the third communication port of another sub-module unit until all the sub-module units have communication lines.

According to some embodiments, the F-type connection is: the M sub-module units comprise x groups of sub-module units and y groups of sub-module units, x and y are positive integers which are more than or equal to 1, and x + y is M; the upper layer controller includes: at least 1+ y controller communication ports; wherein, x sub-module units and a controller communication port form the E-type connection mode; and the y sub-module units and the rest controller communication ports form at least one of the A-type connection mode, the B-type connection mode, the C-type connection mode and the D-type connection mode.

According to some embodiments, all the ac-dc converters comprise a full bridge circuit.

According to some embodiments, two full bridge circuits of two ac-dc converters of the submodule unit comprise a pair of corresponding bridge arms on both sides, and there is an adjustable driving pulse phase shift angle.

According to some embodiments, a phase shift angle of the drive pulse is present between the two legs of each full bridge circuit of the two ac-dc converters of the submodule unit.

The present application further provides a method for controlling the power electronic transformer control architecture, including: the upper-layer controller acquires direct-current voltage information of the sub-module power circuit alternating-current direct-current converter uploaded by each sub-module controller through a communication line, wherein the direct-current voltage information of the sub-module power circuit alternating-current direct-current converter comprises a first direct-current port voltage U1 of a full bridge circuit of a first sub-module controller and a second direct-current port voltage U2 of a full bridge circuit of a second sub-module controller; determining drive pulses for all AC-DC converters based on the first DC port voltage U1 and the second DC port voltage U2.

According to some embodiments, when the communication line is an a-type connection, a B-type connection, a C-type connection, or a D-type connection, the determining the driving pulses of all the ac-dc converters includes: determining a first voltage average U1av of the first DC port voltage U1 and a second voltage average U2av of the second DC port voltage U2 for M sub-module cells; obtaining adjustable driving pulse phase shift angles fi of corresponding bridge arms at two sides of the first full-bridge circuit and the second full-bridge circuit through closed-loop control according to the first voltage average value U1av, the second voltage average value U2av and a set closed-loop reference voltage; determining a first driving pulse phase shift angle fip and a second driving pulse phase shift angle fis according to the ratio of the first voltage average value U1av and the second voltage average value U2av and the adjustable driving pulse phase shift angle fi, the first driving pulse phase shift angle being a driving pulse phase shift angle fip existing between the two legs of the first full-bridge circuit, the second driving pulse phase shift angle being a driving pulse phase shift angle fis existing between the two legs of the second full-bridge circuit; and the first voltage average value U1av, the first driving pulse phase shift angle fip and the adjustable driving pulse phase shift angle fi are issued to the first sub-module controller through a communication route, and the second voltage average value U2av, the second driving pulse phase shift angle fis and the adjustable driving pulse phase shift angle fi are issued to the second sub-module controller, so that the first sub-module controller or/and the second sub-module controller determine the driving pulse of the first full-bridge circuit or/and the driving pulse of the second full-bridge circuit.

According to some embodiments, the first or/and second sub-module controller determines a drive pulse of a first full-bridge circuit or/and a drive pulse of a second full-bridge circuit, comprising: the first sub-module controller or/and the second sub-module controller is/are provided with a reference PWM pulse width; and obtaining the driving pulse of the first full-bridge circuit or/and the driving pulse of the second full-bridge circuit through the synchronization of an upper layer controller and the respective phase shift according to the adjustable driving pulse phase shift angle fi, the first driving pulse phase shift angle fip and the second driving pulse phase shift angle fis.

According to some embodiments, when the communication line is in an E-type connection mode, the determining the driving pulses of all the ac-dc converters includes: determining a first voltage average U1av of the first DC port voltage U1 and a second voltage average U2av of the second DC port voltage U2 for M sub-module cells; obtaining adjustable driving pulse phase shift angles fi of corresponding bridge arms at two sides of the first full-bridge circuit and the second full-bridge circuit through closed-loop control according to the first voltage average value U1av, the second voltage average value U2av and a set closed-loop reference voltage; and transmitting the first voltage average value U1av, the second voltage average value U2av and the adjustable driving pulse phase shift angle fi to the sub-module controllers of all the sub-module units through a chain communication loop, so that the first sub-module controller or/and the second sub-module controller determine the driving pulse of the first full-bridge circuit or/and the driving pulse of the second full-bridge circuit.

According to some embodiments, the first or/and second sub-module controller determines a drive pulse of a first full-bridge circuit or/and a drive pulse of a second full-bridge circuit, comprising: the first sub-module controller and the second sub-module controller simultaneously determine a first driving pulse phase shift angle and a second driving pulse phase shift angle according to the ratio of the first voltage average value U1av or the second voltage average value U2av and the adjustable driving pulse phase shift angle fi, wherein the first driving pulse phase shift angle is a driving pulse phase shift angle fip existing between two bridge arms of the first full-bridge circuit, and the second driving pulse phase shift angle is a driving pulse phase shift angle fis existing between two bridge arms of the second full-bridge circuit; the first sub-module controller or the second sub-module controller is provided with a reference PWM pulse width, keeps synchronization through a communication line, and obtains the driving pulse of the first full-bridge circuit or/and the driving pulse of the second full-bridge circuit according to the respective phase shift of the adjustable driving pulse phase shift angle fi, the first driving pulse phase shift angle fip and the second driving pulse phase shift angle fis.

According to some embodiments, when the communication line is in an F-type connection mode, the determining the driving pulses of all the ac-dc converters includes: the sub-module units of the x parts determine the driving pulses of all the AC-DC converters by adopting a control mode corresponding to the E-type connection mode of the communication line; and the sub-module units of the part y determine the driving pulses of all the AC-DC converters by adopting a control mode corresponding to the communication line, namely an A-type connection mode, a B-type connection mode, a C-type connection mode or a D-type connection mode.

The technical scheme provided by the embodiment of the application provides various specific feasible schemes of a possible driving pulse realization framework aiming at a DAB circuit; through setting up communication lines respectively to DAB circuit high-low pressure side H bridge circuit, compare the control scheme of traditional gentle straight MMC or SVG circuit, under communication lines normal condition, can consider in every module, DAB circuit's coordinated control demand guarantees both sides H bridge circuit pulse drive's synchronism requirement.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings without creative efforts.

Fig. 1 is a schematic diagram of a control architecture provided in an embodiment of the present application.

Fig. 2 is a schematic diagram of a first ac-dc link structure of a first power unit according to an embodiment of the present disclosure.

Fig. 3 is a schematic diagram of a second ac-dc link structure of a second power unit according to an embodiment of the present disclosure.

Fig. 4 is a schematic control structure diagram of an a-type connection method according to an embodiment of the present application.

Fig. 5 is a schematic control structure diagram of a B-type connection method according to an embodiment of the present application.

Fig. 6 is a schematic control structure diagram of a C-type connection method according to an embodiment of the present application.

Fig. 7 is a schematic control structure diagram of a D-type connection method according to an embodiment of the present application.

Fig. 8 is a schematic control structure diagram of an E-type connection method according to an embodiment of the present application.

Fig. 9 is a schematic control structure diagram of an F-type connection method according to an embodiment of the present application.

Fig. 10 is a first schematic circuit structure diagram of a submodule unit provided in an embodiment of the present application.

Fig. 11 is a schematic circuit structure diagram of a submodule unit provided in the embodiment of the present application.

Fig. 12 is a third schematic circuit diagram of a sub-module unit circuit provided in the embodiment of the present application.

Fig. 13 is a flowchart illustrating a control method of a power electronic transformer control architecture according to an embodiment of the present disclosure.

Fig. 14 is a second flowchart illustrating a control method of a power electronic transformer control architecture according to an embodiment of the present application.

Fig. 15 is a third schematic flow chart of a control method of a power electronic transformer control architecture according to an embodiment of the present application.

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are some, but not all, embodiments of the present application. 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 application.

It should be understood that the terms "first", "second", etc. in the claims, description, and drawings of the present application are used for distinguishing between different objects and not for describing a particular order. The terms "comprises" and "comprising," when used in the specification and claims of this application, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

FIG. 1 is a schematic diagram of a control architecture provided in an embodiment of the present application, including an upper controller 1, M sub-module units 11-1M and a communication line, where M is a natural number greater than or equal to 1.

The upper layer controller 1 includes at least one controller communication port. Each submodule unit comprises at least two submodule power circuits and at least one isolating element. The submodule power circuit comprises a submodule controller and an AC-DC converter. The sub-module controller includes at least one sub-module communication port. The ac-dc converter includes at least one ac port and at least one dc port. The isolation element comprises at least two isolation ports, and the isolation ports are connected with the alternating current ports of the alternating current-direct current converter.

The communication line is connected with the upper layer controller and the sub-module controller, or connected with the sub-module controllers of different sub-module units, or connected with different sub-module controllers of the same sub-module unit.

As shown in fig. 1, the upper controller 1 includes at least one controller communication port 11f to 11M. Each sub-module unit includes a first sub-module power circuit 11 a-1 Ma and a second sub-module power circuit 11 b-1 Mb.

The first sub-module power circuits 11a to 1Ma include first sub-module controllers 11a1 to 1Ma1 and first AC-DC converters 11a2 to 1Ma 2. The first sub-module controller 11a1 includes at least 1 communication port 11a5 through which information can be transmitted and received. The first ac-dc converter 11a2 includes at least 1 ac port 11a4 and one dc port 11a3, as shown in fig. 2.

The second sub-module power circuit 11b includes a second sub-module controller 11b1 and a second ac-dc converter 11b 2. The second sub-module controller 11b1 includes at least 1 communication port 11b5 through which information can be transmitted and received. The second ac-dc converter 11b2 includes at least 1 ac port 11b4 and one dc port 11b3, as shown in fig. 3.

As shown in fig. 1, the isolation elements 11 c-1 Mc include at least two isolated ports. Wherein the isolation element 11c includes a first port 11c1 and a second port 11c 2. The first port 11c1 is connected to the ac port 11a4 of the first ac-dc converter, and the second port 11c2 is connected to the ac port 11b4 of the second ac-dc converter.

The communication line connects the upper layer controller 1 with the sub-module controllers, such as 11 d-1 Md, or connects the sub-module controllers of different sub-module units, such as 12d, or connects the different sub-module controllers 11 e-1 Me of the same sub-module unit.

The communication line includes at least one of an a-type connection system, a B-type connection system, a C-type connection system, a D-type connection system, an E-type connection system, and an F-type connection system.

The technical scheme provided by the embodiment provides various specific feasible schemes of possible driving pulse implementation architectures for the DAB circuit; through setting up communication lines respectively to DAB circuit high-low pressure side H bridge circuit, compare the control scheme of traditional gentle straight MMC or SVG circuit, under communication lines normal condition, can consider in every module, DAB circuit's coordinated control demand guarantees both sides H bridge circuit pulse drive's synchronism requirement.

Fig. 4 is a schematic control structure diagram of an a-type connection method according to an embodiment of the present application.

In the type a connection, the upper controller includes at least 2M controller communication ports 11f to 1(2M) f. Every two controller communication ports correspond to one sub-module unit.

As shown in fig. 4, the controller communication ports 11f, 12f correspond to the sub-module unit 11, the controller communication ports 13f, 14f correspond to the sub-module unit 12, and the controller communication ports 1(2M-1) f, 1(2M) f correspond to the sub-module unit 1M.

Each sub-module unit comprises a first sub-module power circuit and a second sub-module power circuit, as shown in fig. 4, the sub-module unit 11 comprises a first sub-module power circuit 11a and a second sub-module power circuit 11 b. The first sub-module power circuit includes a first sub-module controller containing at least one first sub-module communication port. The second sub-module power circuit includes a second sub-module controller including at least one second sub-module communication port. The two controller communication ports are respectively connected with the first sub-module communication port and the second sub-module communication port through communication lines.

Fig. 5 is a schematic control structure diagram of a B-type connection method according to an embodiment of the present application.

In the B-type connection mode, the upper-layer controller comprises at least M controller communication ports 11 f-1 Mf, and each controller communication port corresponds to one sub-module unit.

As shown in fig. 5, the controller communication port 11f corresponds to the sub-module unit 11, the controller communication port 12f corresponds to the sub-module unit 12, and the controller communication port 1Mf corresponds to the sub-module unit 1M.

Each sub-module unit comprises a first sub-module power circuit and a second sub-module power circuit, as shown in fig. 5, the sub-module unit 11 comprises a first sub-module power circuit 11a and a second sub-module power circuit 11 b. The first sub-module power circuit includes a first sub-module controller including at least two first sub-module communication ports. The second sub-module power circuit includes a second sub-module controller including at least one second sub-module communication port. Each controller communication port is connected with one first submodule communication port of the corresponding submodule unit through a communication line, and the other first submodule communication port is connected with the second submodule communication port.

Fig. 6 is a schematic control structure diagram of a C-type connection method according to an embodiment of the present application.

In the C-type connection mode, the upper layer controller includes at least M controller communication ports 11f to 1Mf, each controller communication port corresponding to one sub-module unit.

As shown in fig. 6, the controller communication port 11f corresponds to the sub-module unit 11, the controller communication port 12f corresponds to the sub-module unit 12, and the controller communication port 1Mf corresponds to the sub-module unit 1M.

Each sub-module unit comprises a first sub-module power circuit and a second sub-module power circuit, as shown in fig. 6, the sub-module unit 11 comprises a first sub-module power circuit 11a and a second sub-module power circuit 11 b. The first sub-module power circuit includes a first sub-module controller containing at least one first sub-module communication port. The second sub-module power circuit includes a second sub-module controller including at least two second sub-module communication ports. Each controller communication port is connected with one second submodule communication port of the corresponding submodule unit through a communication line, and the other second submodule communication port is connected with the first submodule communication port.

Fig. 7 is a schematic control structure diagram of a D-type connection method according to an embodiment of the present application.

In the D-type connection mode, the upper layer controller includes at least 2M controller communication ports 11f to 1(2M) f, and every two controller communication ports correspond to one sub-module unit.

As shown in fig. 7, the controller communication ports 11f, 12f correspond to the sub-module unit 11, the controller communication ports 13f, 14f correspond to the sub-module unit 12, and the controller communication ports 1(2M-1) f, 1(2M) f correspond to the sub-module unit 1M.

Each sub-module unit comprises a first sub-module power circuit and a second sub-module power circuit, as shown in fig. 7, the sub-module unit 11 comprises a first sub-module power circuit 11a and a second sub-module power circuit 11 b. The first sub-module power circuit includes a first sub-module controller including at least two first sub-module communication ports. The second sub-module power circuit includes a second sub-module controller including at least two second sub-module communication ports.

One controller communication port of the upper-layer controller is connected with one first sub-module communication port of the corresponding sub-module unit through a communication line, the other controller communication port of the upper-layer controller is connected with one second sub-module communication port through a communication line, and the other first sub-module communication port is connected with the other second sub-module communication port.

Fig. 8 is a schematic control structure diagram of an E-type connection method according to an embodiment of the present application.

In the E-type connection mode, the upper layer controller comprises at least one controller communication port, and each controller communication port corresponds to one sub-module unit.

Each sub-module unit includes a first sub-module power circuit, a second sub-module power circuit, a third communication port, and a fourth communication port. The first sub-module power circuit includes a first sub-module controller containing at least one first sub-module communication port. The second sub-module power circuit includes a second sub-module controller including at least one second sub-module communication port.

The first sub-module communication port is connected with the second sub-module communication port through a communication line. Each controller communication interface is connected with the third communication port of any one sub-module unit through a communication line, and the fourth communication port of the sub-module unit is connected with the third communication port of another sub-module unit until all the sub-module units have communication lines.

Fig. 9 is a schematic control structure diagram of an F-type connection method according to an embodiment of the present application.

In the F-type connection scheme, the M sub-module units include: the device comprises an x group of submodule units and a y group of submodule units, wherein x and y are positive integers which are more than or equal to 1, and x + y is equal to M.

The upper layer controller comprises at least 1+ y controller communication ports. Wherein, x submodule units and a controller communication port form an E-type connection mode. The y sub-module units and the rest of the controller communication ports form at least one of an A-type connection mode, a B-type connection mode, a C-type connection mode and a D-type connection mode.

Fig. 10 is a schematic circuit diagram of a sub-module unit according to an embodiment of the present application, where the ac-dc converters of all the sub-module units include a full-bridge circuit.

Two sides of two full-bridge circuits of two AC-DC converters of the sub-module unit comprise a pair of corresponding bridge arms, and adjustable driving pulse phase shift angles exist. And a phase shift angle of the driving pulse exists between two bridge arms of each full bridge circuit of the two AC-DC converters of the sub-module unit.

As shown in fig. 10, the first full-bridge circuit and the second full-bridge circuit include a pair of corresponding arms on both sides, and there is an adjustable driving pulse phase shift angle denoted as fi, that is, the arm where the switching tubes S1 and S2 are located and the arm where the switching tubes S5 and S6 are located, or the arm where the switching tubes S3 and S4 are located and the arm where the switching tubes S7 and S8 are located. Between the two arms of the first full bridge circuit, there is a phase shift angle of the driving pulse, denoted as fi_pNamely the bridge arm where the switching tubes S1 and S2 are located and the bridge arm where the switching tubes S3 and S4 are located. Between the two arms of the second full bridge circuit, there is a phase shift angle of the driving pulse, denoted as fi_sNamely the bridge arm with the switch tubes S5 and S6 and the bridge arm with the switch tubes S7 and S8.

Fig. 11 is a schematic circuit diagram of a sub-module unit according to an embodiment of the present application, where the sub-module unit is a half-bridge cascade DAB circuit, and is used to construct a power electronic transformer for DC/DC conversion.

Fig. 12 is a schematic circuit structure diagram of a sub-module unit provided in the embodiment of the present application, where the sub-module unit is a full-bridge cascade DAB circuit, and is used to construct an AC/DC conversion power electronic transformer.

Fig. 13 is a flowchart illustrating a control method of a power electronic transformer control architecture according to an embodiment of the present disclosure.

In S110, the upper controller obtains, through the communication line, dc voltage information of the sub-module power circuit ac-dc converter uploaded by each sub-module controller, where the dc voltage information of the sub-module power circuit ac-dc converter includes a first dc port voltage U1 of the full bridge circuit of the first sub-module controller and a second dc port voltage U2 of the full bridge circuit of the second sub-module controller.

In S120, the drive pulses of all the ac-dc converters are determined based on the first dc port voltage U1 and the second dc port voltage U2.

The technical scheme provided by the embodiment and the feedback mode of the capacitor voltage at two sides of the circuit can be used as the calculation basis of DAB multiple phase-shift driving pulse control while completing the basic DAB circuit control, thereby reducing the use requirement of the sensor.

Fig. 14 is a second flowchart illustrating a control method of a power electronic transformer control architecture according to an embodiment of the present application.

When the communication line is an a-type connection method, a B-type connection method, a C-type connection method, or a D-type connection method, the driving pulses of all the ac-dc converters are determined, and the following control is included.

In S110, the upper controller obtains, through the communication line, dc voltage information of the sub-module power circuit ac-dc converter uploaded by each sub-module controller, where the dc voltage information of the sub-module power circuit ac-dc converter includes a first dc port voltage U1 of the full bridge circuit of the first sub-module controller and a second dc port voltage U2 of the full bridge circuit of the second sub-module controller.

In S121, a first voltage average U1av of the first DC port voltage U1 and a second voltage average U2av of the second DC port voltage U2 of the M sub-module cells are determined.

In S122, according to the first voltage average value U1av, the second voltage average value U2av, and the set closed-loop reference voltage, the adjustable driving pulse phase shift angle fi of the corresponding bridge arm at both sides of the first full-bridge circuit and the second full-bridge circuit is obtained through closed-loop control.

In S123, a first driving pulse phase shift angle and a second driving pulse phase shift angle are determined according to a ratio of the first voltage average value and the second voltage average value, and an adjustable driving pulse phase shift angle fi, where the first driving pulse phase shift angle is a driving pulse phase shift angle fip existing between two bridge arms of the first full bridge circuit, and the second driving pulse phase shift angle is a driving pulse phase shift angle fis existing between two bridge arms of the second full bridge circuit.

In S124, the first voltage average value U1av, the first driving pulse phase shift angle fip, and the adjustable driving pulse phase shift angle fi are sent to the first sub-module controller, and the second voltage average value U2av, the second driving pulse phase shift angle fis, and the adjustable driving pulse phase shift angle fi are sent to the second sub-module controller through the communication route, so that the first sub-module controller or/and the second sub-module controller determine the driving pulse of the first full-bridge circuit or/and the driving pulse of the second full-bridge circuit.

The first sub-module controller or/and the second sub-module controller determines a driving pulse of the first full-bridge circuit or/and a driving pulse of the second full-bridge circuit, including the following controls. The first sub-module controller or the second sub-module controller is provided with a reference PWM pulse width. And (3) synchronizing through an upper layer controller, and respectively shifting the phase according to the adjustable driving pulse phase shift angle fi, the first driving pulse phase shift angle fip and the second driving pulse phase shift angle fis to obtain the driving pulse of the first full-bridge circuit or/and the driving pulse of the second full-bridge circuit.

According to the technical scheme provided by the embodiment, the provided feedback mode of the capacitor voltages at two sides of the circuit can be used as the calculation basis of DAB multiple phase-shift driving pulse control while the basic DAB circuit control is completed, the use requirement of the sensor is reduced, and the provided mode of calculating the multiple phase-shift algorithm based on the ratio of the capacitor voltages at two sides is simple and convenient in implementation process and easy for engineering application.

Fig. 15 is a third schematic flow chart of a control method of a power electronic transformer control architecture according to an embodiment of the present application.

When the communication line is of the E-type connection type, the drive pulses of all the ac-dc converters are determined, and the following control is included.

In S110, the upper controller obtains, through the communication line, dc voltage information of the sub-module power circuit ac-dc converter uploaded by each sub-module controller, where the dc voltage information of the sub-module power circuit ac-dc converter includes a first dc port voltage U1 of the full bridge circuit of the first sub-module controller and a second dc port voltage U2 of the full bridge circuit of the second sub-module controller.

In S131, a first voltage average U1av of the first DC port voltage U1 and a second voltage average U2av of the second DC port voltage U2 of the M sub-module cells are determined.

In S132, the adjustable driving pulse phase shift angle fi of the corresponding bridge arm at both sides of the first full-bridge circuit and the second full-bridge circuit is obtained through closed-loop control according to the first voltage average value U1av, the second voltage average value U2av, and the set closed-loop reference voltage.

In S133, the first voltage average value U1av, the second voltage average value U2av, and the adjustable driving pulse phase shift angle fi are sent to the sub-module controllers of all the sub-module units via the chain communication loop, so that the first sub-module controller or/and the second sub-module controller determines the driving pulse of the first full-bridge circuit or/and the driving pulse of the second full-bridge circuit.

The first sub-module controller or/and the second sub-module controller determines a driving pulse of the first full-bridge circuit or/and a driving pulse of the second full-bridge circuit, including the following controls.

The first sub-module controller and the second sub-module controller simultaneously determine a first driving pulse phase shift angle and a second driving pulse phase shift angle according to the ratio of the first voltage average value U1av or the second voltage average value U2av and the adjustable driving pulse phase shift angle fi. The first drive pulse phase shift angle is the drive pulse phase shift angle fip existing between the two legs of the first full-bridge circuit, and the second drive pulse phase shift angle is the drive pulse phase shift angle fis existing between the two legs of the second full-bridge circuit.

The first sub-module controller or the second sub-module controller is provided with a reference PWM pulse width, keeps synchronization through a communication line, and respectively shifts the phase according to an adjustable driving pulse phase shift angle fi, a first driving pulse phase shift angle fip and a second driving pulse phase shift angle fis to obtain a driving pulse of the first full-bridge circuit or/and a driving pulse of the second full-bridge circuit.

Further, when the communication line is of the F-type connection, the driving pulses of all the ac-dc converters are determined, and the following control is included.

And the sub-module units of the x parts determine the driving pulses of all the AC-DC converters by adopting a control mode corresponding to the E-type connection mode of the communication line.

And the sub-module units of the part y determine the driving pulses of all the AC-DC converters by adopting a control mode corresponding to the communication line, namely an A-type connection mode, a B-type connection mode, a C-type connection mode or a D-type connection mode.

The technical scheme provided by the embodiment and the feedback mode of the capacitor voltage at two sides of the circuit can be used as the calculation basis of DAB multiple phase-shift driving pulse control while completing the basic DAB circuit control, thereby reducing the use requirement of the sensor.

The foregoing detailed description of the embodiments of the present application has been presented to illustrate the principles and implementations of the present application, and the description of the embodiments is only intended to facilitate the understanding of the methods and their core concepts of the present application. Meanwhile, a person skilled in the art should, according to the idea of the present application, change or modify the embodiments and applications of the present application based on the scope of the present application. In view of the above, the description should not be taken as limiting the application.