KR102634001B1 - Multiport based dab converter for modularization and fault conditions and operating method of multiport dab converter - Google Patents

Abstract

A multiport DAB converter capable of responding to modularization and fault situations and a method of operating the multiport DAB converter are disclosed. According to an embodiment of the present invention, a multiport DAB converter capable of modularization and responding to fault situations is a QAB comprising a primary inductor (L ₁ ) and three secondary inductors (L ₂ , L ₃ , L ₄ ). (Quadruple-Active-Bridge) Converter; and a first relay coupled in parallel with the primary inductor (L ₁ ), wherein the first relay connects the primary inductor (L ₁ ) in the case of an islanding mode in which a fault occurs at the input port. can be turned on.

Description

A multiport DAB converter capable of responding to modularization and fault situations and a method of operating the multiport DAB converter {MULTIPORT BASED DAB CONVERTER FOR MODULARIZATION AND FAULT CONDITIONS AND OPERATING METHOD OF MULTIPORT DAB CONVERTER}

The present invention is based on power electronics technology, and is a multiport DAB converter and multiport that can respond to fault situations among bidirectional DC/DC converters and solve power synchronization phenomenon. This is about how to operate a DAB converter.

Recently, the need to develop a high-voltage DC (Direct Current) distribution network has been highlighted.

The high-voltage DC distribution network is more efficient than the AC power grid because it does not have skin effect or reactance components, and has the advantage of being able to be used with renewable energy with direct current output, such as solar power and wind power.

High-voltage DC distribution network technology has recently been actively researched as a high-performance power technology for renewable energy and smart grids for efficient use of energy.

QAB (Quadruple-Active-Bridge) converter, among several DC power technology topologies, uses multiple converters that have electrical isolation and enable bidirectional power transfer using the phase difference between both ends of the converter.

A QAB converter can be structurally configured with multiple ports connected to one converter.

The inductor of a QAB converter can be located at both ends of the converter to transfer energy between ports.

In the inductor circuit diagram of the QAB converter, a plurality of output ports are connected to one converter, and the windings between all output ports are connected, which may cause coupling between windings.

The coupling phenomenon between windings can cause a power synchronization phenomenon in which load changes at any output port affect other load ports.

Power synchronization is an unintended power transfer phenomenon that has the disadvantage of reducing the dynamic responsiveness of the system and making output voltage control difficult.

In addition, since a single transformer is used, a converter winding cannot be added each time a load is added, so modularization is not possible.

Therefore, there is an urgent need for the development of an improved converter model that can be modularized and responds to fault situations.

The purpose of the embodiment of the present invention is to provide a multiport DAB converter that can respond to fault situations among bidirectional DC/DC converters, solves the power synchronization phenomenon, and provides a multiport DAB converter capable of responding to modularization and fault situations, and a method of operating the multiport DAB converter. Do it as

According to an embodiment of the present invention, a multiport DAB converter capable of modularization and responding to fault situations is a QAB (Quadruple-Active) converter equipped with a primary inductor (L1) and three secondary inductors (L2, L3, and L4). -Bridge) converter; and a first relay coupled in parallel with the primary inductor (L1), wherein the first relay turns on the primary inductor (L1) in the case of an islanding mode in which a fault occurs at the input port. You can do it.

In addition, according to an embodiment of the present invention, a method of operating a multiport DAB converter capable of responding to modularization and fault situations involves the first inductor (L ₁ ) provided in the QAB (Quadruple-Active-Bridge) converter. 1 Combining relays in parallel; And in the case of islanding mode in which a fault occurs in the input port, the configuration may include turning on the primary inductor (L ₁ ) in the first relay.

According to an embodiment of the present invention, it is possible to provide a multiport DAB converter capable of responding to a fault situation and a multiport DAB converter capable of responding to a modularity and fault situation, which is capable of responding to a fault situation among bidirectional DC/DC converters and solving the power synchronization phenomenon, and a method of operating the multiport DAB converter. You can.

Figure 1 is a block diagram showing the configuration of a multiport DAB converter capable of modularization and responding to fault situations, according to an embodiment of the present invention.
Figure 2 is a circuit diagram of the QAB converter.
Figure 3 is an equivalent inductance circuit diagram of the QAB converter.
Figure 4 is a diagram illustrating a simulation waveform for a power synchronization phenomenon.
Figure 5 is a diagram to explain Grid Connected/Islanding Mode in the QAB converter.
Figure 6 is a diagram to explain the configuration when mounting a relay on a multiport DAB converter.
Figure 7 is an enlarged view of Port 1 in Figure 2.
Figure 8 is a diagram to explain a full bridge in which two switches are ON and two switches are OFF in Port 1.
Figure 9 is a circuit diagram in a fault situation.
Figure 10 is a circuit diagram of the QAB converter.
Figure 11 is a diagram to explain the Grid Connected Mode of the Modular type Multiport DAB converter using a relay.
Figure 12 is a diagram to explain the islanding mode of the Modular type Multiport DAB converter using a relay.
Figure 13 is a diagram for explaining the simulation waveform of the QAB converter using PSIM.
Figure 14 is a diagram explaining the operation algorithm in transition mode.
Figure 15 is a flowchart showing a method of operating a multiport DAB converter capable of responding to modularization and fault situations, according to an embodiment of the present invention.

Hereinafter, embodiments will be described in detail with reference to the attached drawings. However, various changes can be made to the embodiments, so the scope of the patent application is not limited or limited by these embodiments. It should be understood that all changes, equivalents, or substitutes for the embodiments are included in the scope of rights.

The terms used in the examples are for descriptive purposes only and should not be construed as limiting. Singular expressions include plural expressions unless the context clearly dictates otherwise. In this specification, terms such as “comprise” or “have” are intended to designate the presence of features, numbers, steps, operations, components, parts, or combinations thereof described in the specification, but are not intended to indicate the presence of one or more other features. It should be understood that this does not exclude in advance the possibility of the existence or addition of elements, numbers, steps, operations, components, parts, or combinations thereof.

Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as generally understood by a person of ordinary skill in the technical field to which the embodiments belong. Terms defined in commonly used dictionaries should be interpreted as having a meaning consistent with the meaning in the context of the related technology, and unless explicitly defined in the present application, should not be interpreted in an ideal or excessively formal sense. No.

In addition, when describing with reference to the accompanying drawings, identical components will be assigned the same reference numerals regardless of the reference numerals, and overlapping descriptions thereof will be omitted. In describing the embodiments, if it is determined that detailed descriptions of related known technologies may unnecessarily obscure the gist of the embodiments, the detailed descriptions are omitted.

Figure 1 is a block diagram showing the configuration of a multiport DAB converter capable of modularization and responding to fault situations, according to an embodiment of the present invention.

Referring to Figure 1, according to an embodiment of the present invention, a multiport DAB converter (hereinafter abbreviated as 'multiport DAB converter 100') capable of modularization and responding to fault situations includes a QAB converter 110, It can be configured to include a first relay 120 and a second relay 130.

The QAB converter 110 includes a primary inductor (L ₁ ) and three secondary inductors (L ₂ , L ₃ , L ₄ ). Here, the primary side may mean an input port, and the secondary side may mean an output port.

Among the secondary inductors (L ₂ , L ₃ , L ₄ ), the ESS port inductor (L ₄ ) disposed at the bottom of the QAB converter 110 may receive power from the ESS (Energy Storage System) when a fault occurs at the input port. It may be an inductor responsible for transmitting power in islanding mode that is supplied.

The first relay 120 is coupled in parallel with the primary inductor (L ₁ ). That is, the first relay 120 may serve to selectively switch the primary inductor (L ₁ ) on/off.

The first relay 120 can turn on the primary inductor (L ₁ ) in the case of islanding mode in which a fault occurs at the input port.

The second relay 130 is coupled in parallel with the ESS port inductor (L ₄ ) among the secondary inductors (L ₂ , L ₃ , L ₄ ). That is, the second relay 130 may serve to selectively switch the ESS port inductor (L ₄ ) on/off.

In the case of the islanding mode, the second relay 130 turns off the ESS port inductor (L ₄ ), allowing ESS power to be transmitted through the remaining secondary inductors (L ₂ and L ₃ ). .

Additionally, the first relay 120 may turn off the primary inductor (L ₁ ) in the case of Grid Connected Mode in which the fault does not occur in the input port.

In the case of the Grid Connected Mode, the second relay 130 turns on the ESS port inductor (L ₄ ), thereby transmitting power from the input port to the secondary inductor (L ₂ , L ₃ , L ₄ ). Synchronization phenomenon can be prevented.

Additionally, the first relay 120 may be composed of two upper switches (S1, S3) and two lower switches (S2, S4).

In the case of the islanding mode, the first relay 120 can turn on the primary inductor (L ₁ ) by activating only one of the upper switch and the lower switch.

That is, under the islanding mode, the first relay 120 turns on the two upper switches (S1, S3) and turns on the two lower switches (S2, S4) to turn on the primary inductor (L ₁ ). You can. Alternatively, the first relay 120 turns on the primary inductor (L 1 ) by turning off the two upper switches (S1, S3) and turning on the two lower switches (S2, _S4 ) in the islanding mode. You can.

In addition, the QAB converter 110 configures the ports associated with each of the primary inductor (L ₁ ) and the three secondary inductors (L ₂ , L ₃ , and L ₄ ) as a module, so that the inductor according to the load Individual replacement may be possible. That is, the QAB converter 110 configures the port including the secondary inductor (L ₂ , L ₃ , L ₄ ) and the second relay 130 in a module form, and can be replaced on a module basis when necessary. You can.

The purpose of the embodiment of the present invention is to provide a multiport DAB converter that can respond to fault situations among bidirectional DC/DC converters, solves the power synchronization phenomenon, and provides a multiport DAB converter capable of responding to modularization and fault situations, and a method of operating the multiport DAB converter. Do it as

Figure 2 is a circuit diagram of the QAB converter.

Figure 2(a) is a circuit diagram of an existing 4-inductor QAB converter.

Figure 2(b) is a circuit diagram of the multiport DAB converter (3-inductor QAB converter) of the present invention.

As shown in Figure 2(a), the existing 4-inductor QAB converter includes a primary inductor (L ₁ ) of input port port 1 and secondary inductors (L ₂ , L 3 , L) of output port ports 2, ₃ , and 4. ₄ ) is provided. In the existing 4-inductor QAB converter, regardless of Grid Connected Mode (power is supplied smoothly from the input port) and Islanding Mode (power is not supplied from the input port due to a fault), the primary inductor (L ₁ ) is always on. , power synchronization phenomenon may occur in Grid Connected Mode.

Figure 2(b) shows a three-inductor QAB converter without a relay. The three-inductor QAB converter in Figure 2(b) does not synchronize power in Grid Connected Mode, but may be a converter that does not transmit power in Islanding Mode.

The 3-inductor QAB converter, through a relay, turns off the primary inductor (L ₁ ) in Grid Connected Mode and turns on the primary inductor (L ₁ ) in Islanding Mode, suppressing the power synchronization phenomenon and reducing the ESS in islanding mode. Power supply can be made possible.

Figure 3 is an equivalent inductance circuit diagram of the QAB converter.

Figure 3(a) is an equivalent inductance circuit diagram of a conventional 4-inductor QAB converter.

Figure 3(b) is an equivalent inductance circuit diagram of the multiport DAB converter (3-inductor QAB converter) of the present invention.

As shown in FIG. 3(a), the existing 4-inductor QAB converter can position each inductor between DAB converters to ensure equal power exchange between ports.

On the other hand, in the three-inductor QAB converter in Figure 3(b), as the primary inductor (L ₁ ) is turned off in Grid Connected Mode through a relay, P ₂₃ , P ₃₄ , and P ₂₄ are separated, resulting in a power synchronization phenomenon. It can be suppressed.

Figure 4 is a diagram illustrating a simulation waveform for a power synchronization phenomenon.

Figure 4 shows the effect on other ports when reducing the power of port 3 from 1kW to 500W.

As shown in Figure 4, in Grid Connected Mode, as V (430) and I (440) of port 3 change, V (410) of port 1 and V (420) of port 4 change accordingly. Fluctuations may cause power synchronization phenomenon.

DAB (Dual Active Bridge Converter) converter consists of a full bridge with the same input/output and has the advantage of enabling two-way power transmission.

The DAB converter transmits power using the phase difference (Φ) between both ends of the converter, and can determine the magnitude and direction of the transmitted power depending on the magnitude and sign of the phase.

The inductor provided at both ends of the DAB converter may be an energy storage device for transferring energy from the primary side to the secondary side, or from the secondary side to the primary side. The size of the inductance of the inductor is a factor that affects the amount of transmitted power and is a necessary component for transmitting power.

Figure 2(a) is a circuit diagram when there are four inductors (L ₁ , L ₂ , L ₃ , L ₄ ) at both ends of the QAB (Quadruple-Active-Bridge) converter.

L _ij represents the equivalent inductance between ports of the QAB converter, and can be expressed as equations (1) to (3).

[Formula 1]

[Formula 2]

[Formula 3]

As shown in Figure 3(a), in the existing 4-inductor QAB converter, power can be transferred to each other because there is an equivalent inductance between all ports.

Since multiple windings are connected to the port, coupling between windings may occur in the existing 4-inductor QAB converter. For example, in the existing 4-inductor QAB converter, as shown in Figure 4, when the load (power) of port 3 changes from 1kW to 500W, the voltage of not only port 3 (430) but also the remaining ports 2 and 4 (410, 420) It may also cause shaking.

Figure 2(b) is a circuit diagram of a 3-inductor QAB converter (multiport DAB converter) in which L ₁ is removed from the existing 4 inductors.

As shown in FIG. 2(b), L ₁ does not exist in the 3-inductor QAB converter (multiport DAB converter).

3 inductor QAB converter (multiport DAB converter) is L ₁₂ , L ₁₃ , Except for L ₁₄ , the size of the remaining equivalent inductances can be made infinite as shown in Equation (4).

[Formula 4]

L ₁₂ , L ₁₃ , Since the remaining equivalent inductances except L ₁₄ are infinite, the related nodes (L ₂₃ , L ₂₄ , L ₃₄ ) can be open in circuit.

In Figure 3(b), the existing L ₂₃ , L ₂₄ , L ₃₄ shows the equivalent inductance circuit diagram in an open form.

[Formula 5]

Equation 5 is the DAB power formula and can be expressed by applying the equivalent inductance calculated in Equation 4.

According to Equation 5, P ₂₃ , P ₂₄ , P ₃₄ becomes 0, P ₁₂ , P ₁₃ , Each of P ₁₄ has a calculated predetermined value.

In other words, in light of Equation 5, the 3-inductor QAB converter (multiport DAB converter) can prevent the power synchronization phenomenon by removing the primary inductance (L ₁ ) from the existing 4-inductor QAB converter.

Figure 5 is a diagram to explain Grid Connected/Islanding Mode in the QAB converter.

Figure 5(a) illustrates the Grid-connected mode of the Multiport DAB converter, and Figure 5(b) illustrates the Islanding mode of the Multiport DAB converter.

In Figure 5, the arrow direction indicates the power flow direction.

The Grid-Connected Mode in Figure 5(a) may be a mode in which power is supplied from an input port and supplied to multiple output ports.

In Grid-Connected Mode, the Multiport DAB converter can transmit power to the output port if there is a primary inductor (L ₁ ), but power synchronization phenomenon may occur.

If there is no primary inductor (L ₁ ), the Multiport DAB converter in Grid-Connected Mode can supply power to the output port while preventing power synchronization.

Islanding mode in FIG. 5(b) may be a mode in which output is supplied from the port (L ₄ ) connected to the ESS to another port because a fault occurs in the input port and normal power supply is not possible.

In islanding mode, a primary inductor (L ₁ ) may be required. This is because, without the primary side inductor (L ₁ ), the transformer of the Multiport DAB converter is saturated due to the primary side conductor, making normal power transmission from the ESS Port to the output port impossible.

In summary, the multiport DAB converter does not need a primary inductor (L ₁ ) when operating in grid-connected mode, and requires a primary inductor (L ₁ ) when operating in islanding mode.

Figure 6 is a diagram to explain the configuration when mounting a relay on a multiport DAB converter.

Figure 6(a) illustrates a configuration in which a relay is mounted on the ESS port side inductor (L ₄ ), and Figure 6(b) illustrates a configuration in which a relay is mounted on the primary side inductor (L ₁ ).

As shown in FIG. 6(b), the multiport DAB converter 100 uses a relay, a mechanical switch, to turn off the primary inductor (L ₁ ) in Grid Connected Mode and to turn off the primary inductor (L 1 ) in Islanding mode. L ₁ ) can be turned on.

In addition, since the ESS Port side becomes an input port in Islanding Mode, the multiport DAB converter 100 can adopt a configuration in which a relay is mounted on the ESS port side inductor (L ₄ ).

That is, as shown in FIG. 6(a), the multiport DAB converter 100 uses a relay to turn on the ESS port side inductor (L ₄ ) in grid connected mode, and turns on the ESS port side inductor (L 4 ) in islanding mode. L ₄ ) can be turned off.

In summary, the primary inductor (L ₁ ) is turned off in Grid-Connected Mode and turned on in Islanding Mode. On the contrary, the ESS port side inductor (L ₄ ) is turned on in Grid-Connected Mode and turned off in Islanding Mode.

The multiport DAB converter 100 is characterized by configuring an inductor and a relay in parallel at the input/output port, and turning the inductor on/off depending on the mode through the operation of the relay.

The multiport DAB converter 100 of the present invention can be modularized by using individual converters, and the inductor can be selectively turned on/off by adding a relay.

In addition, the multiport DAB converter 100 includes a QAB converter that can have multiple ports in a Dual-Active-Bridge (DAB) converter capable of bi-directional power transfer, thereby supporting various connected distributed power sources and energy storage devices (ESS). It can be operated independently from the power grid by connecting with solar power (PV).

Figure 7 is an enlarged view of Port 1 in Figure 2.

As shown in Figure 7, the relay in Port 1 consists of four switches, the upper switches are S1 and S3, and the lower switches are S2 and S4.

Figure 8 is a diagram to explain a full bridge in which two switches are ON and two switches are OFF in Port 1.

Figure 8(a) shows the full bridge state when the top switches S1 and S3 are OFF and the bottom switches S2 and S4 are ON.

FIG. 8(b) is the reverse of FIG. 8(a) and shows the full bridge state when the upper switches S1 and S3 are ON and the lower switches S2 and S4 are OFF.

If a fault situation occurs in the input port due to various causes such as power outage, overvoltage, or low voltage, the multiport DAB converter 100 turns on only the two lower switches as shown in Figure 8(a), or turns on the upper switches as shown in Figure 8(b). Only two switches can be turned on.

Figure 9 is a circuit diagram in a fault situation.

As shown in Figure 9, the multiport DAB converter 100 creates one path by turning on only two switches and turning the remaining two switches off (OPEN), so that an independent circuit with the fault side can be designed. . Here, the independent circuit is an open circuit that prevents current from being transmitted from the fault side, and through this, the multiport DAB converter 100 can be protected from accidents.

Figure 10 is a circuit diagram of the QAB converter.

As shown in FIG. 10, the multiport DAB converter 100 can be configured by mounting relays in parallel for each of the primary side inductor (L ₁ ) and the ESS port side inductor (L ₄ ).

Figure 11 is a diagram to explain the Grid Connected Mode of the Modular type Multiport DAB converter using a relay.

Figure 11(a) is a circuit diagram of the Modular type Multiport DAB converter in Grid Connected Mode.

Figure 11(b) is an equivalent inductance circuit diagram for the Modular type Multiport DAB converter in Grid Connected Mode.

In FIG. 11, the arrow direction may indicate power flow.

As shown in FIG. 11, Modular type Multiport DAB in Grid Connected Mode, with the primary inductor (L ₁ ) in an inactive (Off) state by the relay, the secondary inductors (L _2, , L ₃ , L ₄ ), power can be supplied without power synchronization phenomenon. In Grid Connected Mode, the ESS port inductor (L ₄ ) can be maintained in the activated (On) state by a relay.

Figure 12 is a diagram to explain the islanding mode of the Modular type Multiport DAB converter using a relay.

Figure 12(a) is a circuit diagram of the Modular type Multiport DAB converter in Islanding Mode.

Figure 12(b) is an equivalent inductance circuit diagram for the Modular type Multiport DAB converter in Islanding Mode.

In FIG. 12, the arrow direction may indicate power flow.

As shown in FIG. 12, in the Modular type Multiport DAB in Islanding Mode due to a fault occurring at the input port, the ESS port inductor (L ₄ ) is deactivated (Off) by the relay, and the remaining secondary inductor (L ESS power can be supplied through ₂ , L ₃ ). In Islanding Mode, the primary inductor (L ₁ ) can be maintained in an activated (On) state by a relay.

Figure 13 is a diagram for explaining the simulation waveform of the QAB converter using PSIM.

Figure 13(a) is a simulation waveform for the QAB converter in Grid Connected Mode.

Figure 13(b) is a simulation waveform for the QAB converter in islanding mode.

In Figure 13, a positive ESS current may mean ESS charging, and a negative ESS current may mean ESS discharging.

The Modular type Multiport DAB converter has the advantage of preventing power synchronization at both input ports when in Grid Connected Mode (Figure 11) and Islanding Mode (Figure 12).

In Grid Connected Mode, Port 1 becomes the input voltage to supply power to the remaining secondary ports, and in Islanding Mode, Port 4 (ESS) becomes the input voltage to supply power to the remaining load ports.

The arrow direction (power flow) in FIGS. 11 and 12 may be determined differently depending on the reference phase. Power has the characteristic of being transferred from a phase-first waveform to a slower waveform (DAB power transfer).

As shown in Figure 13(a), in Grid Connected Mode, the red square wave (Port 1) becomes the reference phase, and power can be supplied to the remaining phases (blue, green, and purple square waves). Additionally, in Grid Connected Mode, the ESS current can be charged to +2.7A.

However, as shown in Figure 13(b), in Islanding Mode, where the red input voltage becomes 0V due to a fault and cannot be supplied from the input port, the ESS port (purple) becomes the reference phase, and other load ports ( Power can be supplied through green, blue, and square waves. At this time, the ESS current can be discharged to -7A. In addition, it can be seen that regardless of the input port, the output power of the load port maintains power desynchronization and is maintained at 1 kW.

In addition, the multiport DAB converter 100 may be modularized according to load by using individual transformers (three) for each port rather than using one multiwinding transformer.

Multiwinding Transformer has the advantage in terms of power density by using only one transformer, but has the disadvantage of having to replace the entire transformer to change the load voltage (change the transformer turns ratio).

The multiport DAB converter 100 is configured in a modular format, so only the ports (Transformers) that require modification can be replaced.

Figure 14 is a diagram explaining the operation algorithm in transition mode.

Figure 14 shows an algorithm that operates in Islanding Mode and Recovery Mode in Grid Connected Mode of the multiport DAB converter 100.

In step 1410, the multiport DAB converter 100 can operate in Grid Connected Mode of Input Relay On and ESS Relay Off.

In step 1420, the multiport DAB converter 100 can determine whether Vin is a fault of less than 360V.

If it is not a fault (No direction in step 1420), the multiport DAB converter 100 may return to step 1410.

In the case of Fault (Yes direction in step 1420), the multiport DAB converter 100 can operate in the islanding mode of Input Relay On and ESS Relay Off in step 1430.

In step 1440, the multiport DAB converter 100 may determine again whether Vin is a fault of less than 360V.

In the case of Fault (Yes direction in step 1440), the multiport DAB converter 100 may return to step 1430.

If it is not a fault (No direction in step 1440), the multiport DAB converter 100 returns to step 1410 and can operate in recovery mode.

The multiport DAB converter 100 can provide a delay time (30ms) with a C code for each section, considering the operation time (2~30ms) of a relay, which is a mechanical switch.

The multiport DAB converter (100) operates in Grid Connected Mode (1410, Fault Flag = 0) 1 second after the relay of the input port is turned on and supplies power to the load port. When a fault situation occurs, the Input/ESS Relay is turned on. It can operate in Islanding Mode (1430, Fault Flag = 1) 30ms after it is turned on.

The multiport DAB converter 100 operates in recovery mode when the input voltage is blocked due to a fault situation and the fault situation is cleared again in the islanding mode in which power is supplied from the ESS, and returns to the grid-connected mode in which power is supplied to the input side. It can work.

The multiport DAB converter 100 of the present invention can be modularized and implement a topology capable of responding to faults.

The multiport DAB converter 100 can be modularized by connecting one converter for each load.

In addition, the multiport DAB converter 100 can enable power delivery even to a fault by selectively using an inductor by adding a relay.

When in Grid-Connected Mode, which supplies power from the input port, the multiport DAB converter 100 can turn on the relay of port 1 and turn off the relay of port 4.

When in islanding mode, where the input port is blocked due to a fault situation and power is supplied to the ESS load port, the multiport DAB converter 100 can supply power by turning off the relay of port 1 and turning on the relay of port 4.

In addition, the multiport DAB converter 100 turns off the switches S1 and S3 of the input port and turns on S2 and S4 to block adverse effects from any fault situation and allows the ESS to supply power to the load.

The multiport DAB converter 100 can be modularized into a QAB multiport converter, protects the power conversion device from various fault accidents, and can supply power using an additional ESS.

The multiport DAB converter 100 can achieve power desynchronization in Grid Connected Mode and Islanding Mode through On/Off of the relay.

Hereinafter, in Figure 15, the operation flow of the multiport DAB converter 100 according to embodiments of the present invention will be described in detail.

Figure 15 is a flowchart showing a method of operating a multiport DAB converter capable of responding to modularization and fault situations, according to an embodiment of the present invention.

The first relay is coupled in parallel to the primary inductor (L ₁ ) provided in the QAB converter in the multiport DAB converter (100) (1510)

The QAB converter includes a primary inductor (L ₁ ) and three secondary inductors (L ₂ , L ₃ , L ₄ ). Here, the primary side may mean an input port, and the secondary side may mean an output port.

Among the secondary inductors (L ₂ , L ₃ , L ₄ ), the ESS port inductor (L ₄ ) placed at the bottom of the QAB converter receives power from the ESS (Energy Storage System) when a fault occurs at the input port. It may be an inductor responsible for power transfer in islanding mode.

The first relay is coupled in parallel with the primary inductor (L ₁ ). That is, the first relay may serve to selectively switch the primary inductor (L ₁ ) on/off.

In the case of islanding mode in which a fault occurs at the input port in the first relay in the multiport DAB converter 100, the primary inductor (L ₁ ) is turned on (1520).

The second relay is coupled in parallel with the ESS port inductor (L ₄ ) among the secondary inductors (L ₂ , L ₃ , L ₄ ). That is, the second relay may serve to selectively switch the ESS port inductor (L ₄ ) On/Off.

In the case of the islanding mode, the second relay turns off the ESS port inductor (L ₄ ), allowing ESS power to be transmitted through the remaining secondary inductors (L ₂ and L ₃ ).

Additionally, the first relay can turn off the primary inductor (L ₁ ) in the case of Grid Connected Mode in which the fault does not occur in the input port.

In the case of the Grid Connected Mode, the second relay turns on the ESS port inductor (L ₄ ), thereby performing a power synchronization phenomenon when transferring power from the input port to the secondary inductor (L ₂ , L ₃ , L ₄ ). It can be prevented.

Additionally, the first relay may be composed of two upper switches (S1, S3) and two lower switches (S2, S4).

In the case of the islanding mode, the first relay can turn on the primary inductor (L ₁ ) by activating only one of the upper switch and the lower switch.

That is, under the islanding mode, the first relay can turn on the two upper switches (S1, S3) and turn on the two lower switches (S2, S4) to turn on the primary inductor (L ₁ ). Alternatively, the first relay can turn on the primary inductor (L ₁ ) by turning off the two upper switches (S1, S3) and turning on the two lower switches (S2, S4) under islanding mode.

In addition, the QAB converter configures the ports associated with each of the primary inductor (L ₁ ) and the three secondary inductors (L ₂ , L ₃ , and L ₄ ) into modules, allowing individual replacement of inductors depending on the load. It can be made possible. That is, the QAB converter can configure the port including the secondary inductor (L ₂ , L ₃ , L ₄ ) and the second relay 130 in a module form, and can be replaced on a module basis when necessary.

The purpose of the embodiment of the present invention is to provide a multiport DAB converter that can respond to fault situations among bidirectional DC/DC converters, solves the power synchronization phenomenon, and provides a multiport DAB converter capable of responding to modularization and fault situations, and a method of operating the multiport DAB converter. Do it as

The operation method of a multiport DAB converter capable of responding to modularization and fault situations according to embodiments may be implemented in the form of program instructions that can be executed through various computer means and recorded on a computer-readable medium. The computer-readable medium may include program instructions, data files, data structures, etc., singly or in combination. Program instructions recorded on the medium may be specially designed and configured for the embodiment or may be known and available to those skilled in the art of computer software. Examples of computer-readable recording media include magnetic media such as hard disks, floppy disks, and magnetic tapes, optical media such as CD-ROMs and DVDs, and magnetic media such as floptical disks. -Includes optical media (magneto-optical media) and hardware devices specifically configured to store and execute program instructions, such as ROM, RAM, flash memory, etc. Examples of program instructions include machine language code, such as that produced by a compiler, as well as high-level language code that can be executed by a computer using an interpreter, etc. The hardware devices described above may be configured to operate as one or more software modules to perform the operations of the embodiments, and vice versa.

Software may include a computer program, code, instructions, or a combination of one or more of these, which may configure a processing unit to operate as desired, or may be processed independently or collectively. You can command the device. Software and/or data may be used on any type of machine, component, physical device, virtual equipment, computer storage medium or device to be interpreted by or to provide instructions or data to a processing device. , or may be permanently or temporarily embodied in a transmitted signal wave. The software may be distributed on a networked computer system and stored or executed in a manner that enables distributed modularity and operation of a multiport DAB converter capable of responding to fault situations. Software and data may be stored on one or more computer-readable recording media.

Although the embodiments have been described with limited drawings as described above, those skilled in the art can apply various technical modifications and variations based on the above. For example, the described techniques may be performed in a different order from the described modularization and operation method of a multiport DAB converter capable of responding to a fault situation, and/or the components of the described system, structure, device, circuit, etc. Appropriate results can be achieved even if the operation method of the multiport DAB converter capable of modularization and responding to fault situations is combined or combined in a different form, or replaced or replaced by other components or equivalents.

Therefore, other implementations, other embodiments, and equivalents of the claims also fall within the scope of the following claims.

100: Multiport DAB converter
110: QAB converter
120: 1st relay
130: 2nd relay

Claims (13)

QAB (Quadruple-Active-Bridge) converter including a primary inductor (L ₁ ) and three secondary inductors (L ₂ , L ₃ , L ₄ ); and
A first relay coupled in parallel with the primary inductor (L ₁ ) and consisting of two upper switches (S1, S3) and two lower switches (S2, S4)
Including,
The first relay is,
In the case of islanding mode where a fault occurs at the input port,
i) turn off the top switches (S1, S3) and turn on the bottom switches (S2, S4), or ii) turn on the top switches (S1, S3) and turn on the bottom switches (S2, S4) By turning OFF, the primary inductor (L ₁ ) is turned on.
Multiport DAB converter capable of modularization and responding to fault situations. According to paragraph 1,
Among the secondary inductors (L ₂ , L ₃ , L ₄ ), a second relay, which is a mechanical switch, is coupled in parallel with the ESS port inductor (L ₄ )
It further includes,
The second relay is,
In the case of the Islanding Mode, by turning off the ESS port inductor (L ₄ ), the ESS power is transmitted through the remaining secondary inductors (L ₂ and L ₃ ).
Multiport DAB converter capable of modularization and responding to fault situations. delete According to paragraph 2,
The second relay is,
In the case of Grid Connected Mode in which the fault does not occur in the input port, by turning on the ESS port inductor (L ₄ ), the input port to the secondary inductor (L ₂ , L ₃ , L ₄ ) Prevents power synchronization phenomenon during power transfer
Multiport DAB converter capable of modularization and responding to fault situations. delete According to paragraph 1,
The QAB converter is,
The ports associated with each of the primary inductor (L ₁ ) and the three secondary inductors (L ₂ , L ₃ , L ₄ ) are configured as modules to enable individual replacement of inductors depending on the load.
Multiport DAB converter capable of modularization and responding to fault situations. Combining the first relay in parallel with the primary inductor (L ₁ ) provided in the QAB (Quadruple-Active-Bridge) converter; and
In the case of islanding mode in which a fault occurs at the input port, turning on the primary inductor (L ₁ ) in the first relay.
Including,
The first relay is,
It consists of two upper switches (S1, S3) and two lower switches (S2, S4),
The step of turning on the primary inductor (L ₁ ) is,
i) turn off the top switches (S1, S3) and turn on the bottom switches (S2, S4), or ii) turn on the top switches (S1, S3) and turn on the bottom switches (S2, S4) Turning on the primary inductor (L ₁ ) by turning OFF
A method of operating a multiport DAB converter capable of responding to modularization and fault situations, including. In clause 7,
The operation method of the multiport DAB converter is:
Among the secondary inductors (L ₂ , L ₃ , L ₄ ) provided in the QAB converter, coupling a second relay, which is a mechanical switch, in parallel with the ESS port inductor (L ₄ ); and
In the case of the above Islanding Mode,
In the second relay, turning off the ESS port inductor (L ₄ ) so that ESS power is transmitted through the remaining secondary inductors (L ₂ and L ₃ ).
A method of operating a multiport DAB converter capable of responding to modularization and fault situations, further comprising: delete According to clause 8,
The operation method of the multiport DAB converter is:
In the case of Grid Connected Mode in which the fault does not occur in the input port,
In the second relay, turning on the ESS port inductor (L ₄ ) to prevent power synchronization phenomenon when transferring power from the input port to the secondary inductor (L ₂ , L ₃ , L ₄ )
A method of operating a multiport DAB converter capable of responding to modularization and fault situations, further comprising: delete In clause 7,
The QAB converter is,
The ports associated with each of the primary inductor (L ₁ ) and the three secondary inductors (L ₂ , L ₃ , L ₄ ) are configured as modules to enable individual replacement of inductors depending on the load.
Operation method of multiport DAB converter capable of modularization and responding to fault situations. A computer-readable recording medium recording a program for executing the method of any one of claims 7, 8, 10, and 12.

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