Dynamic Power Flow Control (DPFC) is a system that regulates power flow in power transmission lines.

Abstract

To provide a dynamic power flow control device that can appropriately respond to dynamic changes in the power system. [Solution] In environment 100, the response-enhanced TAST (RE-TAST) device 104 comprises a response-enhanced high-capacity Sen transformer (REST) ​​and a low-capacity transistorized Sen transformer (TST) having a common transformer. The transformer comprises a multiphase primary winding and multiple secondary windings. The multiple secondary windings are divided into multiple groups, each group comprising a first section associated with the REST and a second section. The first section is connected to multiple power electronics (PE)-based switches and their respective bypass switches, and the second section is connected to multiple PE-based switches and power transistors and their respective bypass switches. The operation of the multiple PE-based switches and their respective bypass switches provides a compensating voltage to adjust the power flow of the transmission line.

Description

[Technical Field]

[0001] This disclosure relates to the field of power control devices, and more particularly to providing a dynamic power flow control device (DPFC) based on a response-enhanced power transistor-assisted Sen transformer (RE-TAST). [Background technology]

[0002] The information described in the background art of this disclosure is intended solely to enhance the general background of the present invention and should not be construed as constituting prior art known to those skilled in the art or as giving any form of suggestion.

[0003] Transmission lines are a vital medium for transmitting electricity between the transmitting and receiving ends. Power systems are becoming increasingly vulnerable to dynamic changes that threaten their safety and stability. Power generation and electricity demand are becoming more flexible and dynamic. To adequately respond to these dynamic changes, power transmission and distribution need to be more flexible. In the age of renewable energy and electric vehicles, the transition to smart grids is essential, and this transition requires the use of technologically advanced and economically practical power flow control devices.

[0004] Various efforts have been made to develop practical power flow control devices. One known conventional solution is the voltage source converter (VSC) based integrated power flow control device (UPFC). This device comprises two VSC converters coupled via a common DC terminal. One VSC converter is connected in parallel to the transmission line via a coupling transformer, and the other VSC converter is inserted in series to the transmission line via an interface transformer. The series converters are controlled to inject a voltage phasor in series with the transmission line, and their magnitude can be varied from zero to a maximum value, and their phase angle can be independently varied from 0° to 360°, all with fast response. The UPFC is equivalent to an inverter-based static synchronous compensator (STATCOM) and static synchronous series compensator (SSSC). The STATCOM is connected in parallel to the busbar and injects current into the power system at the connection point. The SSSC is connected in series with the transmission line and injects voltage in series with the transmission line.

[0005] This UPFC combines the functions of both parallel and series FACTS devices and has three control parameters: voltage regulation of connected busbars, adjustment of series injection voltage magnitude, and adjustment of series injection voltage phase angle. Therefore, it is the most versatile flexible AC transmission (FACTS) device, capable of independently controlling active and reactive power flows in transmission lines. However, the cost of installing and operating a UPFC is extremely high, resulting in only three installations worldwide.

[0006] Another such solution is the Power Transistor Auxiliary Sen Transformer (TAST), which is also a FACTS device capable of operating in power transmission and distribution networks. The TAST consists of a high-capacity Sen transformer (ST) and a low-capacity transistorized Sen transformer (TST). The ST operates in stepwise mode, providing an injection voltage with a limited operating point. Furthermore, the TST operates continuously and, using pulse width modulation (PWM) technology, provides a voltage that can be smoothly changed with a fast response. When the parallel section of the TAST is connected to the busbar and the series section is connected in series to the transmission line, it injects a voltage in series with the transmission line. The series injection voltage of the TAST is the algebraic sum of the voltages of the ST and TST. In this way, by increasing or decreasing the voltage value in the preceding busbar and / or advancing or delaying the voltage phase angle, the voltage magnitude and voltage phase angle of the transmission / distribution line can be controlled dynamically and independently, thereby enabling dynamic and independent control of active and reactive power flows.

[0007] While conventional TASTs offer improved response speed compared to conventional STs, this characteristic does not apply to the entire operating range of TAST. In fact, this characteristic is limited to the operating range of low-capacitance TSTs, which are a part of TAST, and this operating range is only a narrow part of the overall TAST operating range. Within TAST, conventional STs rely on mechanical on-load tap-changing (OLTC) switches, and it takes 2 seconds for the ST to transition from one operating point to another adjacent operating point, which is a long time from the standpoint of power system stability. Naturally, the time required for multiple transitions between the ST's operating points becomes even longer. Therefore, when the desired operating conditions require the ST to transition from one operating point to another, TAST may not be able to provide the required fast response. Thus, the limitation of the fast response characteristic to only the operating range of TSTs, which are a part of TAST, is a drawback of TAST.

[0008] Therefore, there is a need for power flow control devices that overcome the aforementioned limitations and offer further advantages. [Overview of the Initiative] [Problems that the invention aims to solve]

[0009] The above overview is illustrative and not intended to be limiting in any sense. Further embodiments, configurations, and configurations beyond those described above will become apparent from the drawings and the following detailed description.

[0010] In one non-limiting embodiment of the present disclosure, a dynamic power flow control device (DPFC) for regulating power flow in a transmission line is disclosed. The DPFC comprises a response-enhanced high-capacity Sen transformer (REST) ​​and a low-capacity transistorized Sen transformer (TST) configured to have a common transformer. In one exemplary embodiment, the transformer comprises a polyphase primary winding and a plurality of secondary windings. Furthermore, the plurality of secondary windings are divided into a plurality of groups, each group comprising a configurable first section of the secondary winding associated with the REST and a second section of the secondary winding associated with the TST. Furthermore, the configurable first section of the secondary winding is connected to a plurality of power electronics (PE)-based switches and their respective PE-based bypass switches. The second section of the secondary winding is connected to a plurality of other power electronics (PE)-based switches and their respective PE-based bypass switches. PE-based switches connected to a configurable first section of the secondary winding operate discretely in integer periodic on or off modes, while PE-based switches connected to a second section of the secondary winding operate continuously in a PWM-based periodic high-speed on-off mode. Furthermore, by switching multiple configurable first sections and second sections of the secondary winding with different PE-based switches, a compensation voltage is provided to adjust the power flow in the transmission line.

[0011] In another non-limiting embodiment of the present disclosure, a method for adjusting the power flow in a transmission line is disclosed. The method includes the step of configuring a dynamic power flow control device (DPFC) in the transmission line. In one exemplary aspect, the DPFC includes a response-enhanced high-capacity Sen transformer (REST) and a low-capacity transistorized Sen transformer (TST) configured to have a common transformer. Further, the transformer includes a polyphase primary winding and a plurality of secondary windings. Also, the plurality of secondary windings are divided into a plurality of groups, and each group includes a configurable first section of the secondary winding associated with the REST and a second section of the secondary winding associated with the TST. Still further, the configurable first section is connected to a plurality of power electronics (PE)-based switches and respective PE-based bypass switches. The second section of the secondary winding is connected to a plurality of other power electronics (PE)-based switches and respective PE-based bypass switches. The method further includes the step of generating a first compensation voltage by closing one of the plurality of PE-based switches corresponding to the REST. The method further includes the step of generating a second compensation voltage by switching the plurality of PE-based switches corresponding to the TST. Further, the method includes the step of generating a compensation voltage based on the first compensation voltage and the second compensation voltage and injecting it into the transmission line to adjust the power flow.

Brief Description of the Drawings

[0012] [Figure 1] An exemplary environment 100 for implementing a proposed RE-TAST device on a transmission line according to an embodiment of the present disclosure is shown. [Figure 2] FIG. 200 is a structural diagram of a proposed RE-TAST device 104 according to an embodiment of the present disclosure. [Figure 3A] An exemplary circuit configuration 300A of a part of the primary winding and secondary winding of a RE-TAST device according to an embodiment of the present disclosure is shown. [Figure 3B]Shows an exemplary sequence of switching signals corresponding to a REST PE switch and a PE bypass switch according to an embodiment of the present disclosure. [Figure 4A] Shows the circuit configuration 400A of a transistorized AC chopper associated with TST according to an embodiment of the present disclosure. [Figure 4B] Shows an exemplary sequence of switching signals corresponding to a transistorized AC chopper and its PE bypass switch according to an embodiment of the present disclosure. [Figure 5] Figures 5A to 5D show an increase in voltage magnitude performed by a RE-TAST device according to an embodiment of the present disclosure. [Figure 6] Figures 6A to 6F show a decrease in voltage magnitude performed by a RE-TAST device according to an embodiment of the present disclosure. [Figure 7] Figures 7A to 7D show an advance of the phase angle performed by a RE-TAST device according to an embodiment of the present disclosure. [Figure 8] Figures 8A to 8D show a lag of the phase angle performed by a RE-TAST device according to an embodiment of the present disclosure. [Figure 9] Figures 9A to 8D show the simultaneous occurrence of an increase in voltage magnitude and an advance of the phase angle performed by a RE-TAST device according to an embodiment of the present disclosure. [Figure 10] Shows the control region of the increase and decrease of the voltage magnitude and / or the advance / lag of the phase angle performed by a RE-TAST device according to an embodiment of the present disclosure. [Figure 11] Is a flowchart showing an exemplary method 1100 for adjusting the power flow in a transmission line according to an embodiment of the present disclosure.

Mode for Carrying Out the Invention

[0013] The accompanying drawings, incorporated into and constituting part thereof, illustrate exemplary embodiments and, together with the specification, serve to illustrate the disclosed principles. In the drawings, the same numbering is used consistently to refer to similar features and components. Several embodiments of at least one apparatus and method according to the subject matter of the present invention are described below, for illustrative purposes only, with reference to the accompanying drawings.

[0014] The figures illustrate embodiments of the Disclosure for illustrative purposes only. Those skilled in the art will readily recognize from the following description that alternative embodiments of the structures and methods described herein can be applied without departing from the principles of the Disclosure as described herein.

[0015] In this specification, the term “exemplary” means “shown as an example, case, or illustration.” No embodiment or implementation of the subject matter described herein as “exemplary” should necessarily be construed as being superior or better than any other embodiment.

[0016] While various modifications and alternative forms are possible with respect to this disclosure, specific embodiments are shown in the drawings as examples and are described in detail below. However, it should be understood that this disclosure is not intended to limit itself to any particular form disclosed, but rather encompasses all modifications, equivalents, and alternative forms that fall within the spirit and scope of this disclosure.

[0017] The terms “comprise,” “comprising,” or any other variation thereof are intended to mean non-exclusive inclusion. That is, a configuration, apparatus, or method containing a list of components or steps does not include only those components or steps, but may also include other components or steps not explicitly listed, or other components or steps specific to that configuration, apparatus, or method. In other words, one or more elements described as “comprising…” in an apparatus, system, or device do not, unless otherwise specified, exclude the presence of other elements or additional elements in the apparatus, system, or device.

[0018] In the following detailed description of embodiments of the Disclosure, reference will be made to accompanying drawings illustrating specific embodiments that form part of this Specification and enable the implementation of the Disclosure. These embodiments are described in sufficient detail to enable those skilled in the art to implement the Disclosure, and it should be understood that other embodiments may be used and that modifications may be made without departing from the scope of the Disclosure. Therefore, the following description should not be constrained.

[0019] As mentioned in the background technology section, conventional power transistor auxiliary Sen transformers (TASTs) offer improved response speed compared to conventional Sen transformers (STs), but this characteristic does not apply to the entire operating range of TASTs. In fact, this characteristic applies only within the operating range of low-capacitance TSTs, which are a part of TASTs. The operating range of TSTs is only a small part of the operating range of TASTs. In particular, within TASTs, conventional STs rely on mechanical on-load tap-changing (OLTC) switches, so transitions from one operating point to another adjacent operating point of the ST take considerable time, resulting in increased response time and affecting overall performance.

[0020] To overcome this challenge and provide further advantages, this disclosure proposes an improved model of the conventional TAST apparatus. The improved model has the capability to have a wider high-speed response operating range compared to the conventional TAST apparatus. In particular, this disclosure discloses a response-enhanced TAST (RE-TAST) by replacing mechanical OLTC switches with electronic solid-state switches, also known as power electronics (PE) based switches, at a reasonable cost. This disclosure also describes a response-enhanced limited-angle TAST (RE-LA-TAST) apparatus, which extends the high-speed response operating range within a limited operating angle while optimizing the overall cost. In fact, there are no examples of any particular application of UPFC that fully utilize the capability of the full 360° operating range. A detailed description of the proposed RE-TAST apparatus as a DPFC is provided below in conjunction with Figures 1 to 8.

[0021] Figure 1 shows an exemplary environment 100 in which the proposed RE-TAST device is implemented on a power transmission line according to one embodiment of the present disclosure. The exemplary environment 100 has a multiphase voltage V S A power transmission end having a multiphase voltage V m A modified transmission end having a multiphase voltage V r The diagram shows a receiving end having a and a transmission line 102 having. A proposed RE-TAST device 104 is incorporated into the transmission line 102 to regulate the power flow within the transmission line 102. In one embodiment, the RE-TAST device 104 receives a multiphase voltage V from the transmission end. S Receives the compensation voltage V RE-TAST This is generated and injected into transmission line 102. This results in the transmission end voltage V of the transmission end bus on the left side toward RE-TAST. S However, the corrected transmission end voltage V is located on the bus to the right of RE-TAST. m This is modified. In another embodiment, the RE-TAST device 104 can also change the phase angle difference (δ) between the transmitting end and the modified transmitting end. A detailed description of the structure of the RE-TAST device 104 and its voltage and / or phase angle adjustment functions is provided below in conjunction with Figures 2 to 9.

[0022] Figure 2 shows a structural diagram 200 of the proposed RE-TAST device 104 according to one embodiment of the present disclosure. The proposed RE-TAST device 104 comprises a response-enhanced high-capacity Sen transformer (REST) ​​and a low-capacity transistorized Sen transformer (TST) configured to have a common transformer. The transformer has a multiphase primary winding, which forms an excitation unit 202. In one embodiment, the primary winding is a three-phase primary winding and can be configured to receive a three-phase voltage Vs from the transmission end of the transmission line 102. In Figure 2, the transmission voltage is supplied to the excitation unit, and the compensation unit receives power from the excitation unit by induction through transformer action.

[0023] Furthermore, the transformer includes multiple secondary windings, which form a compensation unit 204. In one embodiment, the multiple secondary windings are divided into multiple groups, and each group is a three-phase voltage V S It is associated with the corresponding phase. Furthermore, each group comprises one or more secondary windings, and each of the one or more secondary windings within each group comprises a configurable first section of the secondary winding associated with REST and a second section of the secondary winding associated with TST. Referring to Figure 2, in one embodiment, the multiple secondary windings can be divided into three groups, namely groups 206, 208, and 210. Each group comprises three secondary windings. For example, group 206 may comprise secondary windings a1, b1, and c1. Similarly, group 208 may comprise secondary windings a2, b2, and c2, and group 210 may comprise secondary windings a3, b3, and c3. Furthermore, the windings in each group may comprise 0 to 4 sections associated with REST and 4 to 5 sections associated with TST. However, as will be understood by those skilled in the art, the configuration of the first section of the secondary winding associated with REST is modifiable. Specifically, the RE-TAST device 104 may be configured using only two-thirds of the secondary windings of REST in combination with a complete TST.

[0024] Next, as shown in FIG. 3A, the secondary windings of each group are connected to a plurality of power electronics (PE)-based switches. In particular, FIG. 3A shows an exemplary circuit configuration 300A of the primary winding a and the secondary winding a1 of the RE-TAST device 104 according to an embodiment of the present disclosure. As shown in FIG. 3A and the foregoing description, the secondary winding a1 includes sections of the secondary windings numbered 0 to 4 corresponding to REST and the secondary winding numbered 4 to 5 corresponding to TST. The plurality of PE-based switches PE-SW1 to PE-SW4 are connected to the secondary winding terminal numbers 0 to 4. Further, a plurality of PE-based switches, namely power transistors TR1 to TR4 (shown in FIG. 4A), form the core of TST as indicated by reference numeral 308 in FIG. 3A. Also, REST and TST are connected to corresponding PE-based bypass switches 306 and 310, respectively. Further, as shown in FIG. 3A, the sub-diagrams of reference numerals 304, 306, and 310 show the configuration of the PE switches PE-SW1 to PE-SW4 of REST and the PE-based bypass switch. In one embodiment, by the operation of the plurality of PE-based switches PE-SW1 to PE-SW4 and the plurality of PE-based switches, namely power transistors TR1 to TR4, a compensation voltage V RE-TAST is provided and injected into the power transmission line 102, and the power flow in the power transmission line 102 is adjusted. When there is no need to inject a compensation voltage from REST into the power transmission line 102, the PE-based bypass switch 306 operates. Similarly, when there is no need to inject a compensation voltage from TST into the power transmission line 102, the bypass switch 310 operates. Further, in one embodiment, the power transistors TR1 to TR4, which are a plurality of PE-based switches, may be metal oxide semiconductor field effect transistors (MOSFETs) or insulated gate bipolar transistors (IGBTs). Further, in one embodiment, the plurality of PE-based switches PE-SW1 to PE-SW4 and the PE-based bypass switches 306, 310 may be silicon controlled rectifier (SCR) thyristor-based switches or alternating current triode (TRIAC)-based switches.

[0025] In one embodiment, the number of turns of the secondary second section winding associated with TST is a fraction of the number of turns of the secondary first section associated with REST.

[0026] Figure 3B shows an exemplary sequence of switching signals sent to switch the REST PE switches PE-SW1 through PE-SW4 and their corresponding bypass switches on and off in Figure 3A. In particular, as shown in Figure 3B, it is possible that one of the multiple PE switches PE-SW1 through PE-SW4 is always in the ON state, while all the other PE switches and their corresponding bypass switches are in the OFF state. Alternatively, if the REST compensation voltage is not required, the bypass switches may switch to the ON state when all PE switches PE-SW1 through PE-SW4 are OFF. The OFF SCR / TRAIC switch can withstand the peak reverse voltage of the REST input and, when ON, can pass the maximum current flowing through the REST circuit.

[0027] Figure 4A shows a circuit configuration 400A of a transistorized AC chopper associated with a TST according to one embodiment of the present disclosure. The transistorized AC chopper shown in Figure 4A is a MOSFET or IGBT-based AC chopper comprising four MOSFETs or four insulated-gate bipolar transistors (IGBTs) connected in series. Figure 4A further shows a switching signal source that generates switching signals transmitted to gates G1-G4 of the MOSFETs / IGBTs. In one embodiment, the TST is configured to operate in a continuous and high-speed mode by varying the duty cycle of the switching signals. An exemplary sequence of switching signals transmitted to gates G1-G4 is shown in Figure 4B. In particular, as shown in Figure 4B, there may always be one MOSFET / IGBT switch in the off state and the other three MOSFET / IGBT switches in the on state. The TST ensures fast and continuous transitions from one operating point to another by fine changes in pulse width, while also enabling fast cancellation of the TST voltage by the operation of corresponding PE-based bypass switches. When the MOSFET / IGBT switch is in the off state, it can withstand the peak reverse voltage of the AC chopper input, and when it is in the on state, it allows the maximum current flowing through the AC chopper circuit to pass through.

[0028] Considering the function of the AC chopper in relation to the switching signal, in one embodiment, the AC chopper has three operating modes: active mode, free-wheeling mode, and dead-time mode. In these modes, the chopper supplies energy, performs free-wheeling, and bypasses, respectively. In active mode, a supply voltage appears between the terminals of the corresponding injection transformer of the TST. In the positive half-cycle, the current passes through the body diodes of TR-1 and TR-4, and in the negative half-cycle, it passes through the body diodes of TR-4 and TR-1. The dead time is necessary to prevent current spikes that occur when actual transistors are used. During the dead time, for safe commutation, the switches (TR-1 and TR-2) are turned off simultaneously in the positive half-cycle, and the switches (TR-3 and TR-4) are turned off simultaneously in the negative half-cycle. However, at the same time, a current path must be maintained to avoid voltage spikes. Therefore, regardless of the control strategy determined by the duty cycle, both switches (TR-3 and TR-4) are continuously turned on during the positive half-cycle, and both switches (TR-1 and TR-2) are continuously turned on during the negative half-cycle. During the off period of switches TR-1 and TR-4, the terminals of the injection transformer are isolated from the supply. They are short-circuited through a freewheeling path, and the voltage at the injection transformer terminals becomes zero. Thus, the current in the injection transformer naturally decays through the body diodes of TR-3 and TR-2 during the positive half-cycle, and naturally decays through the body diodes of TR-2 and TR-3 during the negative half-cycle.

[0029] Figures 2 to 4 and their related descriptions detail the structural arrangement and components of the RE-TAST device 104 configured to provide a compensation voltage to adjust the power flow of the transmission line 102. The operation of power flow adjustment by the RE-TAST device 104 is described in detail below. In one embodiment, REST is operated by closing one of the PE-based switches PE-SW1 to PE-SW4, thereby providing a first compensation voltage V REST Provides a first compensation voltage V REST The compensation voltage is V RE-TASTIt is a major component of [the system]. Furthermore, the first compensation voltage V REST It is discretely controlled with fast response from zero to maximum within a 360° angular range. However, the REST compensation voltage V REST If injection is not required, each of the multiple PE-based switches PE-SW1 through PE-SW4 is opened, and the corresponding PE-based bypass switch 306 is closed.

[0030] Conversely, as mentioned above, the TST operates in continuous and high-speed mode by changing the duty cycle of the switching signals sent to gates G1-G4 that drive the AC chopper of the TST308. The TST308 uses a second compensation voltage V TST Provides a second compensating voltage V TST It is continuously controlled from zero to the maximum value within a 360° angle range. In one embodiment, the second compensation voltage V TST The compensation voltage is V RE-TAST It is an auxiliary component of the second compensation voltage V TST The main function of this is to fill the gaps in REST voltage and power flow control, and to ensure that REST, and by extension RE-TAST, is controlled continuously rather than stepwise. For this purpose, the TST308 provides smooth, continuous, and rapidly controllable addition / subtraction and advance / retard voltages. Furthermore, as mentioned above, this auxiliary compensation voltage V TST If there is no need to inject a switch signal, no switching signal is sent to any of the gates G1-G4 of the multiple power transistors TR1-TR4, and the corresponding PE-based bypass switch 310 is closed.

[0031] First compensating voltage V REST and the second compensating voltage V TST Once obtained, these voltages are added together algebraically, resulting in a compensation voltage V that can be injected into transmission line 102. RE-TASTThis represents the following. Furthermore, it will be apparent to those skilled in the art that by changing the magnitude and predetermined angular range of the REST and TST compensation voltages, the RE-TAST device 104 can provide a compensation voltage that covers the entire voltage control region and whose magnitude can be controlled over the entire predetermined angular range. In one embodiment, the predetermined angular range may be 0° to 360°. Over the entire angular range of 0° to 360°, the voltage control region becomes a hexagonal region centered on the tip of the transmitting end voltage, as shown in Figure 10. By independently controlling the voltage magnitude and angle within this hexagonal voltage control region, the active and reactive powers of the transmission line 102 can also be independently controlled within a similar hexagonal region centered on the original power flow value representing the original operating point of the transmission line 102.

[0032] In particular, by applying an appropriate control strategy to the proposed RE-TAST device 104, the RE-TAST device 104 can adjust the series voltage, phase angle, or both of the series voltage and phase angle of the transmission and distribution lines with a high-speed response rate in milliseconds. In one embodiment, the control strategy can control only the resistance, only the reactance, or both the resistance and reactance (impedance) of the transmission and distribution lines. In another embodiment, the control strategy can independently and bidirectionally control active and reactive power flow. These control strategies will be discussed in the following paragraphs. [Voltage magnitude adjustment]

[0033] For the purpose of adjusting the voltage magnitude, the RE-TAST device 104 provides a compensation voltage V RE-TAST The transmitting end voltage V s It can be in phase with or out of phase with the respective transmitting end voltage V sIt is possible to increase or decrease these voltages. For example, to increase the voltage of phase "A" of transmission line 102, as shown in Figure 5, REST needs to provide an additive voltage and TST needs to provide an additive or subtractive voltage. Secondary winding a1 (shown in Figures 2 and 3A) is activated to provide the in-phase, i.e., additive compensation voltage of REST, as shown in Figure 5. Furthermore, an AC chopper attached to section 4-5 of winding a1 is activated to provide the additive voltage of TST, and AC choppers attached to sections 4-5 of windings b1 and c1 (shown in Figure 2) are activated to provide the out-of-phase, i.e., subtractive compensation voltage of TST, as shown in Figure 5. To obtain the subtractive voltage of TST, the duty cycles of the AC choppers attached to sections 4-5 of windings b1 and c1 are set to be equal, and the angle of the output voltages is kept equal at 180°. By appropriately combining the compensation voltages of REST and TST, the magnitude of the desired effective modified transmission end voltage can be achieved flexibly, continuously, and with a fast response. In one embodiment, Figure 5A shows the operating region corresponding to an increase in voltage magnitude. Similarly, Figure 5B shows the summing voltage of REST and the summing / subtracting voltage of TST. It also shows the sending end of phase "A" of transmission line 102 and the resulting effective corrected sending end voltage. Figure 5C shows the corresponding voltages of phases b1 and c1. Figure 5D shows exemplary possible movement of REST from any operating point to any other operating point with a response time in milliseconds. Conversely, to reduce the voltage at the sending end of transmission line 102, windings b1 and c1 are activated to provide an inverse-phase, i.e., subtractive compensation voltage via REST and TST, and winding a1 is activated to provide an in-phase voltage via its TST. By appropriately combining the compensation voltages of REST and TST, the magnitude of the desired effective corrected sending end voltage can be achieved flexibly, continuously, and with a fast response. In particular, Figure 6A shows that the control region of the RE-TAST device 104 is covered for the purpose of reducing the sending end voltage. Furthermore, Figures 6B and 6C show the subtracted voltages of REST and TST, respectively. Figure 6D shows the added voltage of TST. Figure 6E shows the subtracted voltage of TST and the resulting effective corrected transmission end voltage. Figure 6E also shows the subtracted voltage of REST, the added voltage of TST, the transmission end of transmission line 102, the resulting voltage of RE-TAST, and the resulting effective corrected transmission end voltage of transmission line 102.Figure 6F shows an exemplary possible movement of REST from one operating point to another with a response time in milliseconds. Furthermore, it should be noted that in the subtractive operation of REST and TST, phases b1 and c1 are equally tapped, and their respective corresponding AC choppers are equally modulated.

[0034] Furthermore, the same procedure described above can be used to adjust the voltage magnitude of other phases of the transmission line 102. [Phase angle control]

[0035] For the purpose of phase angle control, this specification considers the voltage of phase "A" of the transmission line 102. Furthermore, the proposed RE-TAST device 104 considers the transmission end voltage V s The phase angle can be advanced or delayed. Referring to Figure 2, the sending end voltage V s To advance the phase angle, the REST windings a1 and c1 and the TST windings a1, b1, and c1 are activated to achieve the effective corrected sending end voltage within an angular range of (0° to 120°). By appropriately combining the compensation voltages of REST and TST, the desired phase angle of the effective corrected sending end voltage can be achieved flexibly, continuously, and with high-speed response. Figure 7A shows three examples of advancing the phase angle while keeping the voltage magnitude constant. Figure 7B shows the activated operating point of REST and the corresponding REST voltage. Furthermore, Figure 7C shows the AC chopper voltage of TST and the corresponding TST output voltage. Figure 7D shows exemplary possible shifts of REST from any operating point to any other operating point with response times in milliseconds.

[0036] Conversely, the transmitting end voltage V sTo delay the phase angle, the REST windings a1 and b1 and the TST windings a1, b1, and c1 are activated to achieve an effective corrected sending-end voltage within an angular range of (240° to 360°). By appropriately combining the compensation voltages of REST and TST, the desired phase angle of the effective corrected sending-end voltage can be achieved flexibly, continuously, and with high-speed response. Figure 8A shows three examples of delaying the phase angle while keeping the voltage magnitude constant. Figure 8B shows the REST operating point and the corresponding REST voltage for each of the three examples. Furthermore, Figure 8C shows the AC chopper voltage of the TST and the corresponding TST output voltage. Figure 8D shows exemplary possible shifts of the REST from any operating point to any other operating point with response times in milliseconds.

[0037] It will be obvious to those skilled in the art that the same procedure described above can be used to adjust the voltage phase angle of the other phases of the transmission line 102. [Voltage magnitude and phase angle adjustment]

[0038] By combining the operations of the RE-TAST device 104 regarding the voltage magnitude adjustment and phase angle adjustment described above, the RE-TAST device 104 can simultaneously and selectively increase or decrease the magnitude of the sending end voltage and / or advance or delay the phase angle. Sending end voltage V sTo simultaneously increase the voltage magnitude and advance the phase angle, the REST windings a1 and c1 and the TST windings a1, b1, and c1 are activated to achieve the effective corrected sending end voltage within an angular range of (0° to 120°). By appropriately combining the compensation voltages of REST and TST, the desired effective corrected sending end voltage magnitude and phase angle can be achieved flexibly, continuously, and with high-speed response. Three examples of simultaneously differentiating the voltage magnitude and phase angle are shown, as detailed in the previous paragraph and shown in Figure 9. Figure 9A shows three examples of voltage magnitude increase and phase angle advance. Figure 9B shows the activated operating point of REST and the corresponding REST voltage. Furthermore, Figure 9C shows the AC chopper voltage of TST and the corresponding TST output voltage. Figure 9D shows exemplary possible movement in milliseconds from any operating point of REST to any other operating point.

[0039] It will be obvious to those skilled in the art that the same procedure as described above can be used to simultaneously adjust the voltage magnitude and phase angle of the other phases of the transmission line 102.

[0040] Therefore, with a high-speed response in milliseconds and more flexibility than conventional TAST, the RE-TAST device 104 can simultaneously and independently control active and reactive power flows in both directions. The RE-TAST device 104 can selectively or simultaneously adjust the magnitude and phase angle of the series voltage, and can also control the voltage of the preceding bus. Thus, the RE-TAST device 104 can independently control active and reactive power flows in both directions. This independent and high-speed power flow control is useful for transmitting active power most economically while providing the necessary high-speed response to disturbances. Furthermore, the RE-TAST device 104 can provide a larger series voltage at a lower cost compared to state-of-the-art power flow control devices, particularly UPFCs, making it a more cost-effective candidate for power flow control applications.

[0041] Figure 11 is a flowchart illustrating an exemplary method 1100 for regulating power flow in a power transmission line 102 according to one embodiment of the present disclosure. Method 1100 can also be described in the general context of computer executable instructions. Generally, computer executable instructions include routines, programs, objects, components, data structures, procedures, modules, and functions that perform specific functions or implement specific abstract data types. Among the electronic components of a switching signal generation circuit, there may be electronic chips programmed to generate appropriate switching signals.

[0042] The order of description in Method 1100 should not be interpreted as a restriction, and the method blocks described can be combined in any number and any order to implement the method. In addition, individual blocks can be removed from the method without deviating from the spirit and scope described.

[0043] In step 1102, method 1100 includes the step of configuring a dynamic power flow control (DPFC) on the transmission line 102. In one embodiment, the DPFC is a RE-TAST device 104, which comprises a response-enhanced high-capacity Sen transformer (REST) ​​and a low-capacity transistorized Sen transformer (TST) configured to have a common transformer. Furthermore, the transformer comprises a multiphase primary winding and a plurality of secondary windings. In one embodiment, the plurality of secondary windings are divided into a plurality of groups, each group comprising a configurable first section of the secondary winding associated with the REST and a second section of the secondary winding associated with the TST. Furthermore, the configurable first section of the secondary winding is connected to a plurality of power electronics (PE)-based switches PE-SW1 to PE-SW4 and their respective PE-based bypass switches. Furthermore, the second section of the secondary winding is connected to a plurality of power electronics (PE)-based switches TR1 to TR4 and their respective PE-based bypass switches.

[0044] In step 1104, method 1100 closes one of the multiple PE-based switches PE-SW1 to PE-SW4 to obtain the first compensation voltage V REST The process includes the step of generating a first compensation voltage V. REST It is generated by REST.

[0045] In step 1106, method 1100 provides a second compensating voltage V TST The process includes the step of generating a second compensation voltage V. In one embodiment, the second compensation voltage V TST It is generated by TST.

[0046] In step 1108, method 1100 provides a compensation voltage V RE-TAST The process includes generating a compensation voltage V and injecting it into the transmission line 102 to adjust the power flow in the transmission line 102. In one embodiment, the compensation voltage V RE-TAST The first compensation voltage V REST and the second compensating voltage V TST It is the algebraic sum of .

[0047] The illustrated steps are shown to illustrate exemplary embodiments, and it should be noted that technological advancements may change how specific functions are performed. These examples are presented for illustrative purposes only and are not intended to be limiting. Furthermore, for illustrative purposes, the boundaries of the function blocks are arbitrarily defined. Alternative boundaries can also be defined, as long as the specified functions and their relationships are performed appropriately.

[0048] As shown in Figures 2 to 8, many parts of TAST remain essential in RE-TAST as well.

[0049] The description of embodiments in which multiple components communicate with each other does not mean that all such components are essential. Rather, the description of various optional components demonstrates the possibility of diverse embodiments of the present invention.

[0050] Even when a single device or article is described herein, it is readily apparent that multiple devices / articles (whether or not they operate in coordination) may be used instead of a single device / article. Similarly, even when multiple devices or articles are described herein (whether or not they operate in coordination), it is readily apparent that a single device / article may be used instead of multiple devices / articles, or that a different number of devices / articles than those indicated may be used. The functions and / or features of a device may be embodied by one or more other devices that are not expressly described as having those functions / features. Therefore, other embodiments of the present invention do not necessarily have to include the device itself.

[0051] Finally, the language used herein has been selected primarily for readability and explanatory purposes, and not to define or limit the subject matter of the invention. Accordingly, the scope of the invention is intended to be limited not by the detailed description herein, but by the claims made in an application based on this specification. Therefore, the embodiments of this disclosure are illustrative of, and not limiting, the scope of the invention as described in the appended claims.

[0052] While various aspects and embodiments are disclosed herein, other aspects and embodiments will be apparent to those skilled in the art. The various aspects and embodiments disclosed herein are for illustrative purposes only and are not intended to limit, and the true scope is indicated by the following claims.

[0053] In one embodiment, the proposed RE-TAST device offers a wider high-speed response range compared to conventional TAST, at a lower cost than equivalent rated UPFCs, and within the device's broad design limits, it has high-speed response, error-free operation, an unrestricted full control range, continuous and smooth operation, and independent active and reactive power flow control capabilities.

[0054] In another embodiment, the proposed RE-TAST device has a reconfigurable secondary winding function associated with REST, thereby enabling a RE-TAST device with a full 360° operating range at an optimized cost while reducing the number of components, and having similar high-speed response, error-free operation, an unrestricted full control range, continuous and smooth operation, and independent active and reactive power flow control capabilities within the wide design limits of the device.

[0055] In yet another embodiment, the disclosure provides a customized, but fully functional, angle-limited RE-TAST device (LA-RE-TAST) at an even more optimized cost. This provides similar high-speed response, error-free operation, an unrestricted full control range, continuous and smooth operation, and independent active and reactive power flow control capabilities within the broad design limits of the LA-RE-TAST device.

Claims

1. A dynamic power flow control device (DPFC) (104) that adjusts the power flow in a power transmission line (102), wherein the DPFC (104) It comprises a response-enhanced high-capacity Sen transformer (REST) ​​and a low-capacity transistorized Sen transformer (TST) configured to have a common transformer. The transformer comprises a multiphase primary winding and a plurality of secondary windings. The plurality of secondary windings are divided into a plurality of groups, each group comprising a configurable first section of the secondary winding associated with the REST and a second section of the secondary winding associated with the TST, The configurable first section of the secondary winding is connected to a plurality of power electronics (PE)-based switches (PE-SW1 to PE-SW4) and their respective PE-based bypass switches (306), and the second section of the secondary winding is connected to a plurality of power electronics (PE)-based switches (TR1 to TR4) and their respective PE-based bypass switches (310), The operation of the plurality of PE-based switches (PE-SW1 to PE-SW4), the plurality of power electronics (PE)-based switches (TR1 to TR4), and the respective PE-based bypass switches (306, 310) adjusts the power flow in the transmission line (102) by compensating the voltage (V ＲＥ－ＴＡＳＴ A dynamic power flow control system (DPFC) is provided.

2. The DPFC according to claim 1, wherein the multiphase primary winding of the transformer forms an excitation unit (202).

3. The DPFC according to claim 2, wherein the excitation unit (202) is configured to receive a multiphase voltage (Vs) from the transmission end of the power transmission line (102).

4. The DPFC according to claim 1, wherein the plurality of secondary windings of the transformer form a compensation unit (204).

5. The DPFC according to claim 1, wherein the REST comprises a plurality of PE switches, and the REST operates in discrete mode by switching the PE switches on and off when a switching signal is received.

6. The DPFC according to claim 1, wherein the TST comprises one or more AC choppers, and the TST operates in continuous mode by changing the duty cycle of the switching signals that drive the one or more AC choppers.

7. The aforementioned compensation voltage (V ＲＥ－ＴＡＳＴ ) is the first compensation voltage (V ＲＥＳＴ ) and the second compensation voltage (V ＴＳＴ The DPFC according to claim 1, which is the algebraic sum of ).

8. The first compensation voltage (V ＲＥＳＴ The first compensation voltage (V) is supplied from REST by closing one of the multiple PE-based switches (PE-SW1 to PE-SW4), and the first compensation voltage (V) is supplied by closing one of the PE-based switches (PE-SW1 to PE-SW4). ＲＥＳＴ The DPFC according to claim 7, wherein the angle is discretely controlled from zero to a maximum value within a predetermined angular range and responds on the order of milliseconds.

9. The DPFC according to claim 7, wherein the second compensation voltage (VTST) is supplied from the TST and is continuously controlled from zero to a maximum value within a predetermined angular range and responds on the order of milliseconds.

10. The aforementioned compensation voltage (V ＲＥ－ＴＡＳＴ The magnitude of the compensation voltage (V) ＲＥ－ＴＡＳＴ The DPFC according to claim 1, configured to adjust at least one of the phase angles of ).

11. A method for adjusting the power flow in a power transmission line (102), wherein this method is Step (1102) of configuring a dynamic power flow control device (DPFC) on a power transmission line, The DPFC comprises a response-enhanced high-capacity Sen transformer (REST) ​​and a low-capacity transistorized Sen transformer (TST) configured to have a common transformer. The transformer comprises a multiphase primary winding and a plurality of secondary windings. The plurality of secondary windings are divided into a plurality of groups, each group comprising a configurable first section of the secondary winding associated with the REST and a second section of the secondary winding associated with the TST, The configurable first section of the secondary winding is connected to a plurality of power electronics (PE)-based switches (PE-SW1 to PE-SW4) and their respective PE-based bypass switches (306), and the second section of the secondary winding is connected to a plurality of power electronics (PE)-based switches (TR1 to TR4) and their respective PE-based bypass switches (310), step, By the REST, by closing one of the plurality of PE-based switches (PE-SW1 to PE-SW4), a first compensation voltage (V ＲＥＳＴ ) is generated in step (1104); The TST sets the pulse width value for switching the plurality of PE-based switches (TR1 to TR4), thereby setting the second compensation voltage (V ＴＳＴ The steps of generating (1106) and The first compensation voltage (V ＲＥＳＴ ) and the second compensation voltage (V ＴＳＴ ) based on the compensation voltage (V ＲＥ－ＴＡＳＴ The steps include generating (1108) a power source and injecting it into the power transmission line (102) to adjust the power flow, and Methods that include...

12. The method according to claim 11, wherein the TST comprises one or more alternating current (AC) choppers, and the TST operates in continuous mode by changing the duty cycle of the switching signals that drive the one or more AC choppers.

13. The first compensation voltage (V ＲＥＳＴ ) is discretely controlled, and the second compensation voltage (V ＴＳＴ The method according to claim 11, further comprising the step of continuously controlling ) from zero to a maximum value within a predetermined angular range.

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