Single-core symmetrical phase-shifting transformer and fault ride-through control method and device thereof

Abstract

The invention relates to a single-core symmetrical phase-shifting transformer and a fault ride-through control method and device thereof, the transformer comprises a three-phase voltage-regulating winding, the input connection end of each phase of voltage-regulating winding is connected in series with a first conduction turn-off module, and the output connection end of each phase of voltage-regulating winding is connected in series with a second conduction turn-off module; and a group of rapid zero setting modules are connected in parallel between the input connecting end and the output connecting end of each phase of voltage regulating winding. The on-off module is connected to a connecting lead of a voltage regulating winding of the transformer in series, the quick zero-setting module is connected to the two ends of the voltage regulating winding in parallel, and on or off of the on-off module and the quick zero-setting module is controlled respectively, so that the voltage regulating winding of the transformer is connected to or disconnected from a power transmission line. The single-core symmetric phase-shifting transformer is switched on and switched off, the influence of the phase-shifting angle of the symmetric single-core phase-shifting transformer and the equivalent impedance of the symmetric single-core phase-shifting transformer on line protection is eliminated, and the reliability of line protection is guaranteed.

Description

Technical Field

[0001] The present application relates to the technical field of transformer differential protection, and in particular to a single-core symmetrical phase-shifting transformer and a fault ride-through control method and device thereof. Background Art

[0002] With the development of the power system, the grid structure has become increasingly complex. It has become a huge system that includes multiple types of power sources, multiple types of loads, equipment of different voltage levels, and AC / DC hybrid. This has put forward higher requirements for the reliable and economical operation of the power grid. In the power system, if no control method is adopted, the power flow of the power system will be distributed inversely proportional to the impedance, that is, the natural distribution of power. The natural distribution of power may lead to unreasonable distribution of line flow, affecting the safety of power supply in the power system. 、 Therefore, most power systems have flow control methods to adjust the power transmitted by the lines.

[0003] As a power flow regulating device, the single-core symmetrical phase-shifting transformer can adjust the phase of the current and voltage of the transmission line, thereby regulating the power flow of the line. The single-core symmetrical phase-shifting transformer is generally composed of a voltage regulating winding and an excitation winding connected by a circuit. Affected by the working mode, the single-core symmetrical phase-shifting transformer has different phase shift angles and equivalent impedances at different gears. After being connected to the line, the protection performance of the original single-ended protection such as distance protection is reduced, and the protection has the risk of refusal or misoperation. In summary, in view of the shortcomings of the current fault ride-through after the phase-shifting transformer is connected to the line, it is urgent to propose a new fault ride-through control scheme applied to the single-core symmetrical phase-shifting transformer to ensure the reliability of line protection. Summary of the invention

[0004] In order to overcome the above-mentioned deficiencies of the prior art, the present application provides a single-core symmetrical phase-shifting transformer and a fault ride-through control method and device thereof, which specifically adopts the following technical solutions:

[0005] A single-core symmetrical phase-shifting transformer, comprising a three-phase voltage regulating winding and a three-phase excitation winding, wherein the voltage regulating winding of each phase comprises an input connection terminal located at two ends, an output connection terminal and a lead-out connection terminal located in the middle, the three-phase excitation windings are connected in sequence in an angular shape, and the two ends of the excitation winding of each phase are respectively connected to the lead-out connection terminals of the voltage regulating windings of the other two phases;

[0006] The input connection end of each phase of the voltage regulating winding is connected in series with a first on-off module, and the output connection end of each phase of the voltage regulating winding is connected in series with a second on-off module; a group of fast zeroing modules is provided between the input connection end and the output connection end of each phase of the voltage regulating winding, wherein one end of the fast zeroing module is connected in parallel with one end of the first on-off module biased towards the input connection end, and the other end of the fast zeroing module is connected in parallel with one end of the second on-off module biased towards the output connection end.

[0007] Optionally: the first on / off module and the second on / off module both use a pair of anti-parallel connected thyristors.

[0008] Optionally: the fast zero adjustment module includes a pair of anti-parallel connected thyristors and at least one damping resistor, wherein the damping resistor is connected in series with the anti-parallel connected thyristors.

[0009] Optionally: a current transformer is provided at the input connection end of each phase of the voltage regulating winding, and when a single-core symmetrical phase-shifting transformer is connected to the line, the current at the input connection end of each phase of the voltage regulating winding is collected through the current transformer.

[0010] Optionally: the voltage regulating winding of the single-core symmetrical phase-shifting transformer is provided with a polarity converter, and the leading operation or lagging operation of the single-core symmetrical phase-shifting transformer is switched by adjusting the polarity converter.

[0011] Optionally: the voltage regulating winding of the single-core symmetrical phase-shifting transformer is provided with a plurality of gears, and the size of the phase shift angle is changed by adjusting the gear position of the voltage regulating winding.

[0012] In addition, the present application discloses a fault ride-through control method for the above-mentioned single-core symmetrical phase-shifting transformer, which comprises the following steps:

[0013] Step S1: obtaining the current flowing through the input connection end of each phase voltage regulating winding in the single-core symmetrical phase-shifting transformer;

[0014] Step S2: setting an action criterion for controlling the on / off of the on / off module and the fast zeroing module based on the current at the input connection end of the voltage regulating winding;

[0015] Step S3: Control the actions of the on / off module and the fast zeroing module respectively according to the action criteria to perform fault ride-through or line recovery actions.

[0016] Optional: The action criterion includes a fault occurrence criterion and a line recovery criterion.

[0017] The fault occurrence determination conditions are:

[0018]

[0019] The line recovery determination condition is:

[0020]

[0021] in k is the sampling value of the current transformer at the input connection end of a phase voltage regulating winding in a single-core symmetrical phase-shifting transformer; set is the starting setting; It is the rated current of single-core symmetrical phase-shifting transformer.

[0022] Optionally, the step of controlling the actions of the on / off module and the fast zeroing module respectively according to the action criterion includes:

[0023] when When the line is judged to have a fault, the thyristor of the on / off module is turned off, and the thyristor of the fast zeroing module is turned on. At this time, the voltage regulating winding of the single-core symmetrical phase-shifting transformer is disconnected from the line, the single-core symmetrical phase-shifting transformer is out of operation, and the line distance protection is operated according to the preset protection logic and setting value;

[0024] when When the circuit is judged to be restored to normal, the thyristor of the on / off module is controlled to be turned on, and the thyristor of the fast zero adjustment module is controlled to be turned off. At this time, the voltage regulating winding of the single-core symmetrical phase-shifting transformer is connected to the circuit, and the single-core symmetrical phase-shifting transformer resumes normal operation.

[0025] Furthermore, the present application also discloses a fault ride-through control device for the above-mentioned single-core symmetrical phase-shifting transformer, the device comprising:

[0026] A current measurement module is used to obtain the current flowing through the input connection end of each phase voltage regulating winding in a single-core symmetrical phase-shifting transformer;

[0027] A judgment module is used to set a judgment criterion for controlling the on / off of the on / off module and the fast zeroing module based on the current at the input connection end of the voltage regulating winding;

[0028] The action execution module is used to control the actions of the on / off module and the fast zeroing module respectively according to the action criteria to execute the fault ride-through or line recovery action.

[0029] Beneficial Effects

[0030] The technical solution of this application has the following beneficial effects:

[0031] The single-core symmetrical phase-shifting transformer of the present application connects a conduction and shutdown module in series to the connecting lead of its own voltage-regulating winding, and connects a fast zeroing module in parallel to both ends of the voltage-regulating winding, and controls the shutdown or conduction of the conduction and shutdown module and the fast zeroing module respectively, so that the voltage-regulating winding of the transformer is connected to or disconnected from the transmission line, thereby realizing the input and output of the single-core symmetrical phase-shifting transformer, thereby eliminating the influence of the phase shift angle and its equivalent impedance of the symmetrical single-core phase-shifting transformer on the line protection, and ensuring the reliability of the line protection. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a schematic diagram of the overall structure of a single-core symmetrical phase-shifting transformer in an embodiment of the present application.

[0033] Figure 2 This is a schematic diagram of fault ride-through control of the A-phase voltage regulating winding in a single-core symmetrical phase-shifting transformer in an embodiment of the present application.

[0034] Figure 3 Schematic diagram of the flow of a fault ride-through control method for a single-core symmetrical phase-shifting transformer in an embodiment of the present application.

[0035] Figure 4 Schematic diagram of the structure of a fault ride-through control device for a single-core symmetrical phase-shifting transformer in an embodiment of the present application.

[0036] Figure 5 This is a structural diagram of an electronic device in an embodiment of the present application. DETAILED DESCRIPTION

[0037] The present application is further described below in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application, and cannot be used to limit the scope of protection of the present application. It should be noted that the following detailed descriptions are all exemplary and are intended to provide further explanation of the present application.

[0038] Combination Figure 1 and Figure 2 As shown, the embodiment of the present application specifically discloses a single-core symmetrical phase-shifting transformer, which includes a three-phase voltage regulating winding (A S、 B S、 C S ) and three-phase excitation winding (A E、 B E、 C E ), wherein each phase of the voltage regulating winding includes an input connection terminal, an output connection terminal and a lead-out connection terminal located at two end positions, and the three-phase excitation windings are connected in sequence in an angular shape, and the two ends of the excitation winding of each phase are respectively connected to the lead-out connection terminals of the other two phase voltage regulating windings.

[0039] Combination Figure 1 As shown, Figure 1 The input connection end and output connection end of the voltage regulating winding in the single-core symmetrical phase-shifting transformer are defined as port S and port L, respectively, wherein the current at the input connection end and output connection end of the voltage regulating winding of phase A in the single-core symmetrical phase-shifting transformer are defined as and The currents at the input and output terminals of the B-phase voltage regulating winding in a single-core symmetrical phase-shifting transformer are defined as and The currents at the input and output terminals of the C-phase voltage regulating winding in a single-core symmetrical phase-shifting transformer are defined as and The current flowing out of the same-name end of the A-phase excitation winding is defined as The current flowing out of the same-name end of the B-phase excitation winding is defined as The current flowing out of the same-name end of the C-phase excitation winding is defined as Figure 1 Where a, b, and c represent the lead-out connection terminals of the A-phase, B-phase, and C-phase voltage regulating windings, respectively.

[0040] Furthermore, in the embodiment of the present application, in order to achieve control of the single-core symmetrical phase-shifting transformer to be put into or removed during a transmission line fault so as to eliminate the influence of the phase shift angle and equivalent impedance of the symmetrical single-core phase-shifting transformer on line protection, a first on-off module is connected in series at the input connection end of each phase of the voltage regulating winding, and a second on-off module is connected in series at the output connection end of each phase of the voltage regulating winding; a group of fast zeroing modules is provided between the input connection end and the output connection end of each phase of the voltage regulating winding, wherein one end of the fast zeroing module is connected in parallel with one end of the first on-off module biased toward the input connection end, and the other end of the fast zeroing module is connected in parallel with one end of the second on-off module biased toward the output connection end.

[0041] Specifically, Figure 2As shown, in the embodiment of the present application, the first on-off module and the second on-off module both use a pair of thyristors connected in anti-parallel. The fast zeroing module includes a pair of thyristors connected in anti-parallel and at least one damping resistor, wherein the damping resistor is connected in series with the anti-parallel thyristor. It should be noted that the anti-parallel thyristor in the embodiment of the present application refers to the anode and cathode of the two thyristors being connected in reverse. That is, the anode of one thyristor is connected to the cathode of another thyristor, and the two share a load connection point. This connection method allows current to pass through the load in both directions. Since the gate loses its control function once the thyristor is turned on, the turn-off of the thyristor mainly depends on the anode current being reduced to below the holding current. In an AC circuit, when the AC voltage passes through zero, the anode current naturally decreases, causing the thyristor to automatically turn off. For example, in the present embodiment, when the AC voltage transitions from the positive half cycle to the negative half cycle or from the negative half cycle to the positive half cycle, the voltage passes through zero, and the current flowing through the thyristor also passes through zero at this time, and the thyristor will automatically turn off. In this embodiment, the on-off module includes a pair of anti-parallel thyristors denoted as APT1, which are connected in series with the voltage regulating winding of the single-core symmetrical phase-shifting transformer; and the fast zeroing module includes a pair of anti-parallel thyristors connected in series with a damping resistor, wherein the anti-parallel thyristor is defined as ATP2 and the damping resistor is defined as R s .

[0042] Furthermore, in order to realize the current collection of the input connection end of the voltage regulating winding, the embodiment of the present application is provided with a current transformer at the input connection end of each phase of the voltage regulating winding. When the single-core symmetrical phase-shifting transformer is connected to the line, the current of the input connection end of each phase of the voltage regulating winding is collected through the current transformer, that is, the current of the input connection end of the voltage regulating winding of each phase can be collected and obtained respectively through the current transformer at the input connection end of the voltage regulating winding of each phase: and

[0043] It should be noted that the voltage regulating winding of the single-core symmetrical phase-shifting transformer in the embodiment of the present application is provided with a polarity converter SW, and the single-core symmetrical phase-shifting transformer can be switched to perform leading operation or lagging operation by adjusting the polarity converter SW. In addition, the voltage regulating winding of the single-core symmetrical phase-shifting transformer is provided with a plurality of gears, and the size of the phase shift angle can be changed by adjusting the gear position of the voltage regulating winding (i.e., changing the number of turns of the voltage regulating winding connected to the system).

[0044] In addition, Figure 3 As shown, the present application discloses a fault ride-through control method for the above-mentioned single-core symmetrical phase-shifting transformer, which comprises the following steps:

[0045] Step S1: Obtain the current flowing through the input connection end of each phase voltage regulating winding in the single-core symmetrical phase-shifting transformer; that is, use a current transformer to collect the current of the corresponding phase voltage regulating winding input connection end. In this application, the sampling value of the current transformer at the input side connection end of the voltage regulating winding of the single-core symmetrical phase-shifting transformer is generally defined as

[0046] Step S2: Based on the current setting of the input connection end of the voltage regulating winding, the action criterion for controlling the conduction or shutdown of the conduction and shutdown module and the fast zeroing module is set; when constructing the action criterion in step S2, the judgment threshold is first calculated by the rated current of the single-core symmetrical phase-shifting transformer and the starting constant value, and then the judgment threshold is compared with the sampling value of the current transformer, and the actions of the conduction and shutdown module and the fast zeroing module are controlled respectively according to the comparison result, wherein the conduction and shutdown module and the fast zeroing module adopt the same action criterion, that is, the same comparison result will simultaneously control the conduction and shutdown module and the fast zeroing module to perform different actions. Generally, when the transmission line is in normal operation, the thyristor of the conduction and shutdown module is turned on, and the thyristor of the fast zeroing module is turned off.

[0047] It should be noted that the action criteria described in the embodiment of the present application at least include a fault occurrence determination condition and a line recovery determination condition.

[0048] The fault occurrence determination conditions are:

[0049]

[0050] The line recovery determination condition is:

[0051]

[0052] in k is the sampling value of the current transformer at the input connection end of a phase voltage regulating winding in a single-core symmetrical phase-shifting transformer; set is the starting setting; It is the rated current of single-core symmetrical phase-shifting transformer.

[0053] Step S3: Control the actions of the on / off module and the fast zeroing module respectively according to the action criteria to perform fault ride-through or line recovery actions.

[0054] Specifically, the steps of controlling the actions of the on / off module and the fast zeroing module according to the action criterion in step S3 include:

[0055] when When the fault occurs, it is determined that the line has a fault. At this time, the thyristor of the on-off module is turned off, and the thyristor of the fast zeroing module is turned on, so that the voltage regulating winding of the single-core symmetrical phase-shifting transformer is disconnected from the transmission line, and the single-core symmetrical phase-shifting transformer is shut down. In this state, the line distance protection operates according to the preset protection logic and setting value, and is not affected by the connection of the single-core symmetrical phase-shifting transformer.

[0056] when When the line is restored to normal, the thyristor of the on-off module is turned on and the thyristor of the fast zeroing module is turned off, so that the voltage regulating winding of the single-core symmetrical phase-shifting transformer is connected to the transmission line. At this time, the single-core symmetrical phase-shifting transformer resumes normal operation.

[0057] Based on the above control process, the influence of the phase shift angle and its equivalent impedance of the symmetrical single-core phase-shifting transformer on the line protection can be eliminated, thereby ensuring the reliability of the line protection.

[0058] Further, such as Figure 4 As shown, the present application also discloses a fault ride-through control device for the above-mentioned single-core symmetrical phase-shifting transformer, the device comprising:

[0059] The current measurement module 101 is used to obtain the current flowing through the input connection end of each phase voltage regulating winding in the single-core symmetrical phase-shifting transformer;

[0060] A judgment criterion forming module 102, for setting an action judgment criterion for controlling the on / off of the on / off module and the fast zeroing module based on the current at the input connection end of the voltage regulating winding;

[0061] The action execution module 103 is used to control the actions of the on / off module and the fast zeroing module respectively according to the action criterion, and execute the fault ride-through or line recovery action.

[0062] The device provided in the embodiment of the present application can achieve Figure 1 To avoid repetition, the various processes implemented by the method embodiment will not be described again here.

[0063] like Figure 5 As shown, the embodiment of the present application also provides an electronic device, including a processor and a memory, a program or instruction stored in the memory and executable on the processor, and when the program or instruction is executed by the processor, the following is achieved: Figure 1 The various processes of the method embodiment shown in the figure can achieve the same technical effect. To avoid repetition, they will not be described again here.

[0064] The embodiment of the present application also provides a readable storage medium on which a program or instruction is stored. When the program or instruction is executed by a processor, the above Figure 1 The various processes of the method embodiments described above can achieve the same technical effect, and will not be described again here to avoid repetition.

[0065] The present application also provides a computer program product, including computer instructions, which, when executed by a processor, implement the above Figure 1 The various processes of the method embodiments described above can achieve the same technical effect, and will not be described again here to avoid repetition.

[0066] It should be understood that "one embodiment" or "an embodiment" mentioned throughout the specification means that specific features, structures or characteristics related to the embodiment are included in at least one embodiment of the present application. Therefore, "in one embodiment" or "in an embodiment" appearing throughout the specification does not necessarily refer to the same embodiment. In addition, these specific features, structures or characteristics can be combined in one or more embodiments in any suitable manner. It should be understood that in various embodiments of the present application, the size of the sequence number of the above-mentioned processes does not mean the order of execution, and the execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application. The above-mentioned sequence numbers of the embodiments of the present application are only for description and do not represent the advantages and disadvantages of the embodiments.

[0067] It should be noted that, in this article, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the existence of other identical elements in the process, method, article or device including the element.

[0068] In the several embodiments provided in the present application, it should be understood that the disclosed devices and methods can be implemented in other ways. The device embodiments described above are only schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation, such as: multiple units or components can be combined, or can be integrated into another device, or some features can be ignored or not executed. In addition, the coupling, direct coupling, or communication connection between the components shown or discussed can be through some interfaces, and the indirect coupling or communication connection of the devices or units can be electrical, mechanical or other forms.

[0069] The units described above as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units; they may be located in one place or distributed on multiple network units; some or all of the units may be selected according to actual needs to achieve the purpose of the present embodiment.

[0070] In addition, all functional units in the embodiments of the present application may be integrated into one processing unit, or each unit may be a separate unit, or two or more units may be integrated into one unit; the above-mentioned integrated units may be implemented in the form of hardware or in the form of hardware plus software functional units.

[0071] A person skilled in the art can understand that all or part of the steps of implementing the above method embodiment can be completed by hardware related to program instructions, and the aforementioned program can be stored in a computer-readable storage medium. When the program is executed, it executes the steps of the above method embodiment; and the aforementioned storage medium includes: mobile storage devices, read-only memories (ROM), magnetic disks or optical disks, etc., various media that can store program codes.

[0072] Alternatively, if the above-mentioned integrated unit of the present application is implemented in the form of a software function module and sold or used as an independent product, it can also be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the embodiment of the present application can essentially or in other words, the part that contributes to the prior art can be embodied in the form of a software product, which is stored in a storage medium and includes several instructions for a device (which can be a terminal or a platform, etc.) to execute all or part of the methods described in each embodiment of the present application. The aforementioned storage medium includes: various media that can store program codes, such as mobile storage devices, ROMs, magnetic disks, or optical disks.

[0073] The above is only a preferred implementation of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present application. These improvements and modifications should also be regarded as the scope of protection of the present application.

Claims

1. A single-core symmetrical phase-shifting transformer, characterized in that: It includes a three-phase voltage regulating winding and a three-phase excitation winding, wherein each phase of the voltage regulating winding includes an input connection terminal located at two ends, an output connection terminal and a lead-out connection terminal located in the middle, and the three-phase excitation windings are connected in sequence in an angular shape, and the two ends of each phase of the excitation winding are respectively connected to the lead-out connection terminals of the other two phases of the voltage regulating windings; The input connection end of each phase of the voltage regulating winding is connected in series with a first on-off module, and the output connection end of each phase of the voltage regulating winding is connected in series with a second on-off module; a group of fast zeroing modules is provided between the input connection end and the output connection end of each phase of the voltage regulating winding, wherein one end of the fast zeroing module is connected in parallel with one end of the first on-off module biased towards the input connection end, and the other end of the fast zeroing module is connected in parallel with one end of the second on-off module biased towards the output connection end.

2. The single-core symmetrical phase-shifting transformer according to claim 1, characterized in that: The first on / off module and the second on / off module both use a pair of anti-parallel connected thyristors.

3. The single-core symmetrical phase-shifting transformer according to claim 1, characterized in that: The fast zero adjustment module includes a pair of anti-parallel connected thyristors and at least one damping resistor, wherein the damping resistor is connected in series with the anti-parallel connected thyristors.

4. The single-core symmetrical phase-shifting transformer according to claim 1, characterized in that: A current transformer is provided at the input connection end of each phase of the voltage regulating winding. When the single-core symmetrical phase-shifting transformer is connected to the line, the current at the input connection end of each phase of the voltage regulating winding is collected through the current transformer.

5. The single-core symmetrical phase-shifting transformer according to claim 1, characterized in that: The voltage regulating winding of the single-core symmetrical phase-shifting transformer is provided with a polarity converter, and the leading operation or lagging operation of the single-core symmetrical phase-shifting transformer is switched by adjusting the polarity converter.

6. The single-core symmetrical phase-shifting transformer according to claim 1, characterized in that: The voltage regulating winding of the single-core symmetrical phase-shifting transformer is provided with a plurality of gears, and the size of the phase shift angle can be changed by adjusting the gear position of the voltage regulating winding.

7. A fault ride-through control method for a single-core symmetrical phase-shifting transformer according to any one of claims 1 to 6, characterized in that: The steps include: Step S1: obtaining the current flowing through the input connection end of each phase voltage regulating winding in the single-core symmetrical phase-shifting transformer; Step S2: setting an action criterion for controlling the on / off of the on / off module and the fast zeroing module based on the current at the input connection end of the voltage regulating winding; Step S3: Control the actions of the on / off module and the fast zeroing module respectively according to the action criteria to perform fault ride-through or line recovery actions.

8. The fault ride-through control method according to claim 7, characterized in that: The action criteria include fault occurrence judgment conditions and line recovery judgment conditions. The fault occurrence determination conditions are: The line recovery determination condition is: in k is the sampling value of the current transformer at the input connection end of a phase voltage regulating winding in a single-core symmetrical phase-shifting transformer; set is the starting setting; It is the rated current of single-core symmetrical phase-shifting transformer.

9. The fault ride-through control method according to claim 8, characterized in that: The steps of controlling the actions of the on / off module and the fast zeroing module respectively according to the action criterion include: when When the line is judged to have a fault, the thyristor of the on / off module is turned off, and the thyristor of the fast zeroing module is turned on. At this time, the voltage regulating winding of the single-core symmetrical phase-shifting transformer is disconnected from the line, the single-core symmetrical phase-shifting transformer is out of operation, and the line distance protection is operated according to the preset protection logic and setting value; when When the circuit is judged to be restored to normal, the thyristor of the on / off module is controlled to be turned on, and the thyristor of the fast zero adjustment module is controlled to be turned off. At this time, the voltage regulating winding of the single-core symmetrical phase-shifting transformer is connected to the circuit, and the single-core symmetrical phase-shifting transformer resumes normal operation.

10. A fault ride-through control device for a single-core symmetrical phase-shifting transformer according to any one of claims 1 to 6, characterized in that: The device comprises: A current measurement module is used to obtain the current flowing through the input connection end of each phase voltage regulating winding in a single-core symmetrical phase-shifting transformer; A judgment module is used to set a judgment criterion for controlling the on / off of the on / off module and the fast zeroing module based on the current at the input connection end of the voltage regulating winding; The action execution module is used to control the actions of the on / off module and the fast zeroing module respectively according to the action criteria to execute the fault ride-through or line recovery action.

Images