Inverted phase-shift transformer, inverted phase-shift transformer control method, controller, and medium

Abstract

This application provides a flip-type phase-shifting transformer, a control method for the flip-type phase-shifting transformer, a controller, and a medium, relating to the field of power flow control in power systems. It includes: an excitation winding unit, a series winding unit, and a bridge switching unit; the series winding unit is connected in series between the power supply side and the load side of the transmission line; the bridge switching unit includes a first switching branch and a second switching branch; one end of the first switching branch is connected to the power supply side, and the other end is connected to the power take-off terminal of the excitation winding unit; one end of the second switching branch is connected to the load side, and the other end is connected to the power take-off terminal of the excitation winding unit; in a first state, the bridge switching unit conducts the first switching branch to form a first excitation circuit between the excitation winding unit and the power supply side; in a second state, it conducts the second switching branch to form a second excitation circuit between the excitation winding unit and the load side. This application embodiment can increase the regulation performance and regulation accuracy of the equipment.

Description

Technical Field

[0001] This application relates to the field of power flow control in power systems, and more particularly to a flip-type phase-shifting transformer, a flip-type phase-shifting transformer control method, a controller, and a medium. Background Technology

[0002] A phase-shifting transformer is a power flow regulation device that optimizes energy distribution and enhances system stability. Currently, the regulation range and accuracy of phase-shifting transformers mainly depend on the voltage rating and tap settings of the windings. Limited by manufacturing costs and process complexity, it is difficult to increase the regulation area and number of regulation points of a phase-shifting transformer by significantly increasing the number of winding taps or improving the insulation level. This makes it difficult for existing equipment to meet the increasingly complex demands for refined power flow regulation in the power grid without significantly increasing costs.

[0003] Therefore, how to expand the adjustment range and increase the number of adjustment points of the phase-shifting transformer without increasing the number of winding taps and the voltage rating has become an urgent technical problem to be solved. Summary of the Invention

[0004] The main purpose of the application embodiments is to propose a flip-type phase-shifting transformer, a flip-type phase-shifting transformer control method, a controller, and a medium. The aim is to achieve the flipping of the source side and load side positions by switching the conduction arms of the bridge circuit. By changing the excitation mode, the adjustment area is expanded and the number of adjustment points is doubled without increasing the winding taps and voltage rating, thereby improving the adjustment performance and adjustment accuracy.

[0005] To achieve the above objectives, a first aspect of the present application provides a flip-type phase-shifting transformer, characterized in that it includes: an excitation winding unit, a series winding unit, and a bridge switching unit; The series winding unit is connected in series between the power supply side and the load side of the transmission line; The bridge-type switching unit includes a first switching branch and a second switching branch; One end of the first switching branch is connected to the power supply side, and the other end is connected to the power supply terminal of the excitation winding unit; one end of the second switching branch is connected to the load side, and the other end is connected to the power supply terminal of the excitation winding unit; the bridge switching unit is configured to switch between a first state and a second state: in the first state, the first switching branch is turned on so that the excitation winding unit and the power supply side form a first excitation circuit; in the second state, the second switching branch is turned on so that the excitation winding unit and the load side form a second excitation circuit.

[0006] In some embodiments, the transmission line is a three-phase line, and the excitation winding unit includes three excitation windings connected in parallel using a star connection, each corresponding to one of the three phases of the three-phase line; The series winding unit includes nine series windings; three series windings are connected in series on each phase of the three-phase line; for any phase line, the three series windings connected in series on that phase line are respectively coupled to the three excitation windings to generate compensation voltage components corresponding to different phases on that phase line.

[0007] In some embodiments, both the first switching branch and the second switching branch are composed of anti-parallel thyristor groups; The first switching branch includes at least one set of first anti-parallel thyristors, which are connected between the power supply side and the power take-off terminal of the excitation winding unit. The second switching branch includes at least one set of second anti-parallel thyristors, which are connected between the load side and the power take-off terminal of the excitation winding unit. The flip-type phase-shifting transformer also includes a controller connected to the bridge switching unit, which controls the bridge switching unit to switch between the first state and the second state by triggering the conduction and cutoff of the anti-parallel thyristor group.

[0008] In some embodiments, an on-load tap changer is provided on the series winding unit, which is used to adjust the ratio of the number of turns of the series winding connected to the transmission line.

[0009] To achieve the above objectives, a second aspect of this application provides a control method for a flip-type phase-shifting transformer, the method being applied to a controller, the controller being used to control the flip-type phase-shifting transformer as described in any one of claims 1 to 4, the method comprising: Obtain the power flow regulation target of the power system; Based on the power flow regulation target, the target operating state is determined from the first state and the second state; Send a switching control signal to the bridge switching unit to activate the first switching branch or the second switching branch, so that the flip-type phase-shifting transformer enters the target working state; The target tap of the series winding unit is determined according to the power flow regulation target, and the series winding unit is controlled to switch to the target tap to generate a target compensation voltage in the transmission line that satisfies the power flow regulation target.

[0010] In some embodiments, determining the target operating state from the first state and the second state according to the power flow regulation target includes: Determine the initial adjustment range corresponding to the first state and the flip adjustment range corresponding to the second state; Determine whether the power flow regulation target is within the initial regulation range; if the power flow regulation target is within the initial regulation range, determine that the target's working state is the first state. If the current regulation target is outside the initial regulation range but within the flip regulation range, the target working state is determined to be the second state.

[0011] In some embodiments, determining the target gear of the series winding unit based on the power flow regulation target includes: Based on the power flow regulation target, calculate the required active power regulation and reactive power regulation. Based on the active power adjustment and the reactive power adjustment, the voltage amplitude required for each phase component in the series winding unit is calculated. Under the target operating state, the gear combination of the series winding unit is matched according to the voltage amplitude required for each phase component, and the gear combination is determined as the target gear.

[0012] In some embodiments, sending a switching control signal to the bridge switching unit includes: If the target operating state is the first state, a first trigger signal is sent to turn on the first switching branch connected between the power supply side and the excitation winding unit, and to turn off the second switching branch. If the target operating state is the second state, a second trigger signal is sent to turn on the second switching branch connected between the load side and the excitation winding unit, and the first switching branch is turned off, so as to use the load side voltage after superimposing the target compensation voltage as the excitation voltage.

[0013] To achieve the above objectives, a third aspect of the present application provides a controller, which includes a memory and a processor. The memory stores a computer program, and the processor executes the computer program to implement the flip-type phase-shifting transformer control method described in the second aspect above.

[0014] To achieve the above objectives, a fourth aspect of the present application provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the flip-type phase-shifting transformer control method described in the second aspect above.

[0015] The flip-type phase-shifting transformer, its control method, controller, and dielectric proposed in this application introduce a bridge switching unit connected between the excitation winding unit and the power supply and load sides, and configures a first switching branch and a second switching branch. This allows the power take-off terminal of the excitation winding to no longer be fixed but can flexibly switch between a first state (connected to the power supply side) and a second state (connected to the load side). This topology enables the device to actively select the voltage source of the excitation circuit while maintaining the physical connection position of the series winding. This constructs a new excitation mode based on the load-side voltage (i.e., the voltage after superimposed compensation voltage), in addition to the traditional source-side excitation mode. The introduction of this mode essentially establishes two distinct voltage regulation logics. Based on this dual-mode switching mechanism, this application utilizes the switching of the bridge arm of the bridge circuit to achieve the flipping of the source-side and load-side positions. By changing the excitation method, it expands the regulation area and doubles the number of regulation points without increasing the winding taps or voltage ratings, thereby improving regulation performance and accuracy. Attached Figure Description

[0016] Figure 1 This is a circuit diagram of the flip-type phase-shifting transformer provided in an embodiment of this application; Figure 2 This is a circuit diagram of a flip-type phase-shifting transformer provided in another embodiment of this application; Figure 3 This is a flowchart of the control method for the flip-type phase-shifting transformer provided in the embodiments of this application; Figure 4 This is a flowchart of a control method for a flip-type phase-shifting transformer provided in another embodiment of this application; Figure 5 This is a schematic diagram of the initial adjustment range of the flip-type phase-shifting transformer provided in an embodiment of this application; Figure 6 This is a schematic diagram of the flip-type phase-shifting transformer's flip-type adjustment range provided in the embodiments of this application; Figure 7 This is a schematic diagram of the final adjustment range of the flip-type phase-shifting transformer provided in the embodiments of this application; Figure 8 This is a flowchart of a control method for a flip-type phase-shifting transformer provided in another embodiment of this application; Figure 9 This is a schematic diagram of the hardware structure of the controller provided in the embodiments of this application. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0018] It should be noted that although functional modules are divided in the device schematic diagram and a logical order is shown in the flowchart, in some cases, the steps shown or described may be performed in a different order than the module division in the device or the order in the flowchart. The terms "first," "second," etc., in the specification, claims, and the aforementioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.

[0019] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing embodiments of this application only and is not intended to limit this application.

[0020] First, let's analyze some of the terms used in this application: Phase Shifting Transformer (PST): A type of transformer used in power systems. Its main function is to change the phase angle and amplitude difference of the voltage across the transmission line by introducing a controllable compensation voltage (usually changing the phase, but some types, such as Sen transformers, can also adjust the amplitude) into the transmission line, thereby controlling the active and reactive power transmitted in the line.

[0021] Power flow refers to the distribution and flow of voltage, current, active power, and reactive power in a power system. Power flow control refers to the artificial guidance of electrical energy transmission along predetermined paths and values ​​by adjusting parameters in the power network (such as voltage amplitude, phase, and impedance) to solve transmission congestion, optimize load distribution, or improve system stability.

[0022] The flip-type phase-shifting transformer, flip-type phase-shifting transformer control method, controller and medium provided in the embodiments of this application are specifically described through the following embodiments. First, the flip-type phase-shifting transformer in the embodiments of this application is described.

[0023] Figure 1 This is an optional circuit diagram of the flip-type phase-shifting transformer provided in this application embodiment. The flip-type phase-shifting transformer includes: an excitation winding unit, a series winding unit, and a bridge switching unit; The series winding unit is connected in series between the power supply side and the load side of the transmission line; The bridge switching unit includes a first switching branch and a second switching branch; One end of the first switching branch is connected to the power supply side, and the other end is connected to the power supply terminal of the excitation winding unit; one end of the second switching branch is connected to the load side, and the other end is connected to the power supply terminal of the excitation winding unit; the bridge switching unit is configured to switch between a first state and a second state: in the first state, the first switching branch is turned on so that the excitation winding unit and the power supply side form a first excitation circuit; in the second state, the second switching branch is turned on so that the excitation winding unit and the load side form a second excitation circuit.

[0024] The beneficial effects of this application's embodiments include, but are not limited to: by introducing a bridge switching unit connected between the excitation winding unit and the power supply side and load side, and configuring a first switching branch and a second switching branch, the power take-off terminal of the excitation winding is no longer fixed to a single state, but can be flexibly switched between a first state (connected to the power supply side) and a second state (connected to the load side). This topology allows the device to actively select the voltage source of the excitation circuit while maintaining the physical connection position of the series winding unchanged, thereby constructing a new excitation mode based on the load side voltage (i.e., the voltage after superimposed compensation voltage) in addition to the traditional source-side excitation mode. The introduction of this mode essentially establishes two completely different voltage regulation logics. Based on this dual-mode switching mechanism, this application uses the switching of the bridge arm of the bridge circuit to realize the flipping of the source-side and load-side positions. By changing the excitation method, without increasing the winding taps and voltage levels, it achieves the expansion of the regulation area and the doubling of the number of regulation points, thereby improving regulation performance and regulation accuracy.

[0025] Among them, the excitation winding unit is as follows Figure 1 As shown in the dashed box at the bottom left, the excitation winding unit mainly consists of the primary winding of the transformer. In this embodiment, the transmission line is a three-phase AC line, therefore the excitation winding unit includes three excitation windings (labeled A, B, and C in the figure). One end of each of the three excitation windings is connected to the neutral point and grounded (i.e., a star connection is used), while the other end serves as the power take-off terminal (i.e., the lead-out terminal connected to the bottom of the bridge switching unit in the figure) to receive the externally input excitation voltage. The main function of the excitation winding is to transmit the acquired excitation voltage to the series winding unit on the secondary side through the principle of electromagnetic induction.

[0026] Series winding unit such as Figure 1 As shown in the dashed box on the right, the series winding unit is located on the secondary side of the transformer, and its physical location is connected in series to the power supply side of the transmission line (as shown in the figure). , , (end) and load side (in the figure) , , Between the terminals. Specifically, each phase of the three-phase line has three independent series windings connected in series. Taking phase A as an example, on the power supply side... With load side Three windings are connected in series (marked in the diagram). , , These three windings are magnetically coupled to the A-phase, B-phase, and C-phase excitation windings on the primary side, respectively. For example, the windings... Coupled to the A-phase excitation winding, it is used to generate a voltage component in phase with the A-phase voltage; winding Coupled to the B-phase excitation winding, it is used to generate a voltage component that lags / leads the A-phase by a certain angle (typically 120°); the winding Coupled to the C-phase excitation winding, it is used to generate a voltage component that lags the A-phase by a certain angle (usually -120°). Through the vector superposition of these three series windings, a compensation voltage of arbitrary amplitude and phase can be injected into the line.

[0027] In some embodiments, but in practical applications, each series winding is typically equipped with an on-load tap changer to change the number of turns connected in the winding, thereby adjusting the magnitude of the aforementioned voltage components.

[0028] Please see Figure 2 The figure illustrates the circuit topology details and power device connection method of the bridge switching unit provided in the embodiment of this application.

[0029] In this embodiment, considering the high voltage and high current operating environment of the power system, both the first switching branch and the second switching branch in the bridge switching unit are composed of anti-parallel thyristor groups.

[0030] like Figure 2 As shown, the basic units constituting the first and second switching branches are both anti-parallel thyristor pairs. Each basic switching unit contains two unidirectional thyristors, where the anode of the first thyristor is electrically connected to the cathode of the second thyristor, and the cathode of the first thyristor is electrically connected to the anode of the second thyristor. Since the transmission line transmits alternating current, the current direction changes periodically. The anti-parallel structure ensures that the branch has bidirectional current-carrying capacity in the conducting state, enabling complete conduction of the alternating current waveform. Furthermore, to withstand the voltage levels of high-voltage transmission lines (e.g., 110kV, 220kV, or higher), the first switching branch (green marked in the figure) and the second switching branch (blue marked in the figure) are typically composed of multiple anti-parallel thyristor units connected in series to form a valve group. Series cascading: such as... Figure 2As shown by the dashed line, each switching branch is actually composed of N pairs of the aforementioned anti-parallel thyristors connected in series (the value of N depends on the system voltage level and the withstand voltage of a single thyristor, with a redundancy margin). Through series stacking, the system high voltage is evenly distributed to each basic switching unit. The input terminal of the first switching branch (green branch) is electrically connected to the power supply side of the transmission line (e.g., Figure 1 In The first branch (node) has its output terminal connected to the power supply terminal of the excitation winding unit, serving as the conventional mode channel. The second switching branch (blue branch) has its input terminal electrically connected to the load side of the transmission line (e.g., ...). Figure 1 In The output terminal is also connected to the power supply terminal of the excitation winding unit, and this branch serves as the switching mode channel.

[0031] In some embodiments, the flip-type phase-shifting transformer is further equipped with a controller connected to the gate of the thyristor via optical fiber or cable. The controller has pre-set interlocking logic and a state machine for controlling the bridge switching unit to seamlessly switch between a first state and a second state. Entering the first state (traditional phase-shifting transformer state): When the system needs to perform adjustments within the initial range, the controller sends a trigger pulse to the thyristor of the first switching branch (green branch) to turn it on; simultaneously, the controller blocks the trigger pulse of the second switching branch (blue branch) to turn it off. At this time, the current path is power supply side - first switching branch - excitation winding, realizing pre-adjustment excitation.

[0032] Entering the second state (flip state): When the system determines that the adjustment target exceeds the initial range or is in the flip adjustment region, the controller performs a switching operation. First, the controller cancels the trigger signal of the first switching branch. After the current crosses zero and naturally turns off, it sends a trigger pulse to the second switching branch to turn it on. At this time, the current path becomes load side - second switching branch - excitation winding. Since the load side voltage includes the compensation voltage generated by the series winding, the excitation source undergoes a physical position flip, thus realizing the adjusted excitation.

[0033] Through this switching method, this embodiment can complete the change of excitation source within milliseconds, without mechanical contact wear, thus ensuring the long-term reliability and response speed of the flip-type phase-shifting transformer.

[0034] Figure 3 This is an optional flowchart of the flip-type phase-shifting transformer control method provided in the embodiments of this application.

[0035] The control method for the flip-type phase-shifting transformer is applied to the controller of the flip-type phase-shifting transformer described above. The control method for the flip-type phase-shifting transformer may include, but is not limited to, steps 301 to 304.

[0036] Step 301: Obtain the power flow regulation target of the power system.

[0037] Step 302: Determine the target working state from the first state and the second state according to the power flow adjustment target.

[0038] Step 303: Send a switching control signal to the bridge switching unit to activate the first switching branch or the second switching branch, so that the flip-type phase-shifting transformer enters the target working state.

[0039] Step 304: Determine the target tap of the series winding unit according to the power flow regulation target, and control the series winding unit to switch to the target tap so as to generate the target compensation voltage that meets the power flow regulation target in the transmission line.

[0040] In step 301 of some embodiments, the controller receives instructions from the upper-level dispatch center through a communication interface, or reads sensor data installed on key nodes of the transmission line, thereby resolving the power flow regulation target of the power system. This power flow regulation target is typically embodied in specific electrical quantity values, such as setpoints for active power transmission, setpoints for reactive power transmission, or adjustment requirements for voltage amplitude and phase at specific nodes. These values ​​reflect the current grid's specific expectations for energy allocation optimization or system stability maintenance, constituting the input benchmark for subsequent control strategy calculations.

[0041] In step 302 of some embodiments, the controller performs a matching analysis based on the acquired power flow regulation target and the device's regulation capability under different excitation modes to determine whether to adopt the traditional regulation mode (first state) or the flipped regulation mode (second state). This process involves projecting the target electrical quantity value onto a preset regulation range model. If the target is within the initial regulation area covered by the power supply side excitation, the first state is locked; if the target is outside the initial regulation area but within the extended area covered by the load side closed-loop excitation, the flipped second state is determined to be the target operating state, thereby ensuring that the device always operates under the optimal topology that meets the regulation requirements.

[0042] Please see Figure 4 In some embodiments, step 302 may include, but is not limited to, steps 401 to 403.

[0043] Step 401: Determine the initial adjustment range corresponding to the first state and the flip adjustment range corresponding to the second state.

[0044] Step 402: Determine whether the power flow regulation target is within the initial regulation range. If the power flow regulation target is within the initial regulation range, determine the target's working state as the first state.

[0045] Step 403: If the power flow regulation target exceeds the initial regulation range but is within the flip regulation range, determine the target working state as the second state.

[0046] In step 401 of some embodiments, a two-dimensional coordinate system is established based on the current circuit parameters, and two different operating boundaries are defined in this coordinate system. Specifically, the controller first determines, based on the mathematical model of the transformer in the first state (source-side excitation), the following... Figure 5 The initial adjustment range is shown. Figure 5 As shown, this range is typically hexagonal, containing several discrete initial adjustment points (red dots in the figure). These points correspond to the end positions of the compensation voltage vector that the series winding can output under different tap combinations. Simultaneously, based on the mapping relationship when the transformer is in its second state, the following is calculated: Figure 6 The flip adjustment range is shown. (As shown) Figure 6 As shown, due to the feedback introduced by the excitation voltage on the load side, the range is no longer a regular hexagon, but a fan-shaped or curved polygonal area after conformal transformation. The flip adjustment points (blue dots in the figure) contained therein are significantly different from the initial points in terms of distribution density and coverage position, especially extending a larger adjustment distance to the right x-axis direction.

[0047] In step 402 of some embodiments, the obtained power flow regulation target (represented by specific voltage and power coordinate points) is subjected to geometric inclusion analysis with the calculated initial regulation range to determine whether the coordinate points representing the power flow regulation target fall inside or above the hexagonal boundary of the initial regulation range. If the determination result is yes, it indicates that the current regulation demand has not exceeded the capability limit of the traditional transformer mode, and the controller then locks the first state as the target operating state, thereby prioritizing the maintenance of the power supply side excitation operation logic without requiring bridge arm switching operation.

[0048] In step 403 of some embodiments, when it is determined that the power flow regulation target falls within... Figure 5 When the target point is outside the hexagonal boundary shown, the controller further determines whether the target point is located within... Figure 6 Within the indicated flip adjustment range. For example... Figure 7 As shown, the final adjustment range is essentially the union of the initial adjustment range and the flip adjustment range. If the target point exceeds the initial hexagon but falls within... Figure 6 The curved area shown (i.e. Figure 7 (The area covered only by the blue dots), or it falls into Figure 7In areas where both types of points overlap and higher adjustment precision is required, the controller determines the target operating state as the second state. At this time, the equipment will switch to load-side excitation, utilizing... Figure 6 The unique adjustment capability shown is used to capture the target point.

[0049] Through steps 401 to 403 described above, the embodiments of this application construct as follows: Figure 7 The composite adjustment plane is shown. Figure 7 As can be visually demonstrated, compared to the traditional range with only red dots, the final adjustment range not only expands in area (particularly filling the high-amplitude adjustment blind zone on the right), but also fills the gaps between red dots in the overlapping area with blue dots, greatly increasing the density of adjustment points. This control logic enables the flip-type phase-shifting transformer to automatically activate its hidden secondary adjustment capability through software-level state selection without changing the physical winding design, thereby achieving more precise coverage and control of power grid flow.

[0050] In step 303 of some embodiments, the controller generates a corresponding pulse trigger command or level control signal based on the determined target operating state, and sends it to the thyristor gate of the bridge switching unit through the drive circuit. When the first state is confirmed, the control signal drives the first switching branch connected to the power supply side to conduct; when the second state is confirmed, the control signal drives the second switching branch connected to the load side to conduct and turns off the first switching branch, thus establishing an excitation path that introduces compensation voltage feedback. The flipping of the excitation source position is completed through this on / off operation of the physical circuit.

[0051] Please see Figure 8 In some embodiments, step 303 may include, but is not limited to, steps 801 to 803.

[0052] Step 801: Based on the power flow regulation target, calculate the required active power regulation and reactive power regulation.

[0053] Step 802: Based on the active power regulation and reactive power regulation, calculate the voltage amplitude required for each phase component in the series winding unit.

[0054] Step 803: Under the target operating state, match the gear combination of the series winding unit according to the voltage amplitude required for each phase component, and determine the gear combination as the target gear.

[0055] In step 801 of some embodiments, the controller first analyzes the acquired power flow regulation target. Typically, the power flow target is given in the form of desired active and reactive power. The controller collects real-time operating data of the transmission line (such as voltage, current, power factor, etc.), calculates the difference between the current actual power and the desired power, and obtains the active power regulation amount and reactive power regulation amount. Subsequently, based on the impedance parameters of the transmission line and the power flow equation, the controller inversely solves the above power regulation amounts to obtain the required compensation voltage vector. This vector contains two key parameters: the required voltage amplitude change and the required phase shift angle, which directly reflect the geometric characteristics of the voltage vector that the flip-type phase-shifting transformer needs to inject into the system to achieve the power flow target.

[0056] In step 802 of some embodiments, the controller performs a vector decomposition operation. Since the series winding unit in this embodiment has three independent coils coupled to the three-phase excitation windings A, B, and C respectively in series on each phase line, these three coils actually constitute three basis vectors on the complex plane at 120° angles to each other. The controller applies a vector projection or coordinate transformation algorithm to decompose and project the total compensation voltage vector calculated in step 801 onto the directions of these three basis vectors, thereby accurately calculating the voltage amplitude component that each independent series winding needs to contribute to synthesize the total vector.

[0057] In step 803 of some embodiments, the controller maps the calculated theoretical voltage amplitude of each phase component to discrete ranges of the physical device. Since the regulation of the on-load tap changer is not continuous but is achieved through a finite number of ranges (e.g., each range adjusts the rated voltage by 1%), the controller needs to search and match in a preset range parameter library to find an optimal range combination that minimizes the error between the actual voltage vector generated by this range and the theoretically calculated value.

[0058] Through steps 801 to 803 above, the embodiments of this application make full use of the multi-degree-of-freedom structure of the series winding unit. Through vector synthesis at the algorithm level, the device can use discrete gear combinations to approximate compensation voltages of arbitrary direction and magnitude, thereby achieving independent and flexible control of active and reactive power while ensuring adjustment accuracy.

[0059] In step 304 of some embodiments, the controller, having established the correct excitation circuit, further calculates the compensation voltage vector required to achieve the power flow regulation target and maps it to a specific turns ratio configuration of the series winding units. The controller then sends a stepping command to the drive mechanism of the on-load tap changer, driving the mechanical contacts to switch to the corresponding target position, changing the number of turns of the coil connected in series to the line, thereby inducing precise amplitude and phase components in the transmission line, and finally synthesizing the target compensation voltage that meets the expectations, achieving fine-grained control of the line power flow.

[0060] Through steps 301 to 304 above, after obtaining the adjustment requirements, the embodiments of this application can intelligently switch between two complementary excitation topologies. By utilizing the rapid switching on and off of the bridge circuit, the static hardware resources are dynamically reconstructed into two systems with differentiated adjustment characteristics due to different excitation source positions. In conjunction with the fine adjustment of the tap, without changing the transformer's insulation design and winding scale, the original single adjustment plane is successfully expanded into a composite adjustment plane including the flip mapping region, which greatly improves the phase-shifting transformer's coverage and control accuracy for complex power flow conditions.

[0061] It should be noted that the bridge circuit has two arms. When the green arm is conducting, the flip-type phase-shifting transformer operates in the traditional phase-shifting transformer state. At this time, the excitation winding of the flip-type phase-shifting transformer is connected in parallel to the power supply side. The excitation winding obtains the three-phase excitation voltage from the source side of the line and transmits it to the series winding on the secondary side through the electromagnetic induction of the transformer. An on-load tap changer is installed on the series winding to adjust the amplitude of the transmitted excitation voltage before it is fed into the line, thereby forming a compensation voltage. Because each phase of the line has three series windings of phases A, B, and C, the compensation voltage... It consists of three parts: a voltage with the same phase as the current phase, a voltage leading the current phase by 120°, and a voltage lagging the current phase by 120°. The voltage with the same phase as the current phase increases the system voltage amplitude; the voltage leading the current phase by 120° decreases the system voltage amplitude and leads the phase; and the voltage lagging the current phase by 120° decreases the system voltage amplitude and lags the phase. By coordinating the amplitudes and effects of these three components through the series winding positions, decoupled regulation of the system voltage phase and amplitude can be achieved. If the number of series winding positions is k, then the number of initial adjustment points is 3. k 2 +3 k +1.

[0062] If the conducting arm of the bridge circuit is switched to the blue arm, the operating state of the flip-type phase-shifting transformer changes to the flip state. At this time, the power supply and load sides of the flip-type phase-shifting transformer are reversed. The excitation winding is connected in parallel to the load side, while the power supply side is at the end of the series winding. The excitation voltage obtained by the excitation winding is no longer the constant source-side three-phase voltage, but rather the load-side three-phase voltage after the source-side voltage is superimposed with the compensation voltage. Therefore, the excitation voltage itself will be affected by the compensation voltage and the regulation effect. That is, the circuit is in a closed-loop operating state. Even if the same gear selection is used, the resulting regulation effect will be completely different from that of the traditional phase-shifting transformer. Specifically, under a certain gear configuration, the turns ratio produced in the traditional phase-shifting transformer state is K, and the phase shift angle is φ. Then, the turns ratio produced in the corresponding flip state is 1 / K, and the phase shift angle is -φ. Therefore, the initial 3 k 2 +3 k +1 initial adjustment point will map out 3 k 2 +3 k After adding one flip and adjusting the position, excluding the common zero adjustment point, we can ultimately obtain 6. k 2 +6 k With an additional adjustment point, the final adjustment range will be the sum of the initial adjustment range and the adjustment range after flipping.

[0063] Furthermore, by combining the topology and the equivalent circuit diagram of the transformer, the input-output characteristics of the flip-type phase-shifting transformer can be analyzed, assuming... U SA , U SB and U SC These are the three-phase source-side voltages. U LA , U LB and U LC These are the three-phase load-side voltages. U A 、U B and U C It is the three-phase voltage of the excitation winding. U a1 , U b1 and U c1 It is the voltage of the series winding of phase A, 3. U a2 , U b2 and U c2It is the voltage of the B-phase 3-series winding. U a3 , U b3 and U c3 It is the voltage of the C-phase 3-series winding. I SA , I SB and I SC It is the three-phase source-side current. I LA , I LB and I LC These are the three-phase load-side currents. I A 、I B and I C It is the three-phase current of the excitation winding. Z C It is the leakage impedance of the excitation winding. Z c1 , Z c2 and Z c3 These are the leakage impedances of the series windings that are in phase with, lagging behind, and leading the main phase of this line, respectively. K 1. K 2 and K 3. The turns ratio of the series windings that are in phase with, lagging behind, and leading the main phase of this line, respectively.

[0064] When the flip-type phase-shifting transformer is in the first state, i.e., the traditional phase-shifting transformer state, the voltage and current phasors of phase A before and after compensation are: (1.1) (1.2) Based on the transformer turns ratio, the voltage and current relationships of each winding in phase A can be derived: (1.3) (1.4) (1.5) (1.6) Considering that only positive-sequence components exist during normal operation, therefore under positive-sequence conditions: (1.7) (1.8) (1.9) Therefore, 12 equations containing 14 variables have been established. The electrical quantities on the power supply side and the load side can be obtained by simplifying equations 1.1 to 1.9. U SA , I SA , U LA The relation is as follows: (1.10) Simplifying equation 1.10, we get: (1.11) (1.12) Where K is the overall amplitude factor, and its value is: (1.13) φ is the phase shift angle, and with respect to it we have: (1.14) It is the overall internal impedance of the FST, which is generated by the combined internal impedance of all windings: (1.15) From the input-output characteristic equation of Equation 1.15, it can be seen that the existence of K provides the ability to adjust the amplitude of the system node voltage, and the existence of φ provides the ability to adjust the phase of the system node voltage. Assuming that K1, K2, and K3 range from 0 to 0.5, and each has 4 levels, then according to Equation 1.15, the initial adjustment range under the conventional state can be plotted as follows: Figure 5 As shown, the initial adjustment range is hexagonal, containing a total of 61 initial adjustment points, which is the adjustment effect that the traditional mode can achieve.

[0065] Further switching the conducting arms of the bridge circuit, when it is in the flipped state, the voltage and current phasors of phase A before and after compensation are: (1.16) (1.17) Based on the transformer turns ratio, the voltage and current relationships of each winding in phase A can be derived: (1.18) (1.19) (1.20) (1.21) Considering that only the positive sequence component exists during normal operation in the flipped state, therefore, under the positive sequence condition: (1.22) (1.23) (1.24) Therefore, 12 equations containing 14 variables have been established. The electrical quantities on the power supply side and the load side can be obtained by simplifying equations 1.16 to 1.24. U SA , I SA , U LA The relation is as follows: (1.25) Simplifying equation 1.25, we get: (1.26) (1.27) in It is the overall amplitude multiplier in the flipped state, and its value is: (1.28) The phase shift angle in the flipped state is given by: (1.29) From Equation 1.26, the input-output characteristic equation under the FST flip state, it can be seen that the two-dimensional regulation capability is still maintained under the flip state. Based on Equation 1.26, the flip regulation range under the flip state can be plotted, as follows: Figure 6 As shown, the flip adjustment range presents as a curved hexagon. The straight boundary and trajectory in the initial adjustment range become circular boundary and trajectory after flip mapping, containing a total of 61 flip adjustment points. Their distribution differs significantly from the initial adjustment points, with the furthest flip adjustment point reaching the position (2,0), effectively filling the gaps in the traditional mode. The final adjustment range is the superposition of the initial adjustment range and the flip adjustment range, as shown... Figure 7 As shown, the final adjustment range area is significantly increased compared to the traditional mode, effectively expanding the amplitude adjustment range. The number of adjustment points in the final adjustment range reaches 121. These adjustment points not only broaden the amplitude modulation and phase shift range, but also fill the point vacuum area in the initial adjustment range, improving the density of adjustment points and adjustment accuracy.

[0066] This application also provides a controller, which includes a memory and a processor. The memory stores a computer program, and the processor executes the computer program to implement the aforementioned flip-type phase-shifting transformer. This controller can include any smart terminal such as a tablet computer or in-vehicle computer.

[0067] Please see Figure 9 , Figure 9 The hardware structure of a controller according to another embodiment is illustrated. The controller includes: The processor 901 can be implemented using a general-purpose CPU (Central Processing Unit), microprocessor, application-specific integrated circuit (ASIC), or one or more integrated circuits, and is used to execute relevant programs to implement the technical solutions provided in the embodiments of this application. The memory 902 can be implemented as a read-only memory (ROM), static storage device, dynamic storage device, or random access memory (RAM). The memory 902 can store the operating system and other application programs. When the technical solutions provided in the embodiments of this specification are implemented through software or firmware, the relevant program code is stored in the memory 902 and is called and executed by the processor 901 using the flip-flop phase-shifting transformer of the embodiments of this application. The input / output interface 903 is used to implement information input and output; The communication interface 904 is used to enable communication and interaction between this device and other devices. Communication can be achieved through wired means (such as USB, Ethernet cable, etc.) or wireless means (such as mobile network, WIFI, Bluetooth, etc.). Bus 905 transmits information between various components of the device (e.g., processor 901, memory 902, input / output interface 903, and communication interface 904); The processor 901, memory 902, input / output interface 903, and communication interface 904 are connected to each other within the device via bus 905.

[0068] This application also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the aforementioned flip-type phase-shifting transformer.

[0069] Memory, as a non-transitory computer-readable storage medium, can be used to store non-transitory software programs and non-transitory computer-executable programs. Furthermore, memory may include high-speed random access memory, and may also include non-transitory memory, such as at least one disk storage device, flash memory device, or other non-transitory solid-state storage device. In some embodiments, memory may optionally include memory remotely located relative to the processor, and these remote memories can be connected to the processor via a network. Examples of such networks include, but are not limited to, the Internet, intranets, local area networks, mobile communication networks, and combinations thereof.

[0070] It should be noted that the software tools or components not belonging to our company that appear in the embodiments of this application are merely examples and do not represent actual use.

[0071] The embodiments described in this application are for the purpose of more clearly illustrating the technical solutions of the embodiments of this application, and do not constitute a limitation on the technical solutions provided by the embodiments of this application. As those skilled in the art will know, with the evolution of technology and the emergence of new application scenarios, the technical solutions provided by the embodiments of this application are also applicable to similar technical problems.

[0072] Those skilled in the art will understand that the technical solutions shown in the figures do not constitute a limitation on the embodiments of this application, and may include more or fewer steps than shown, or combine certain steps, or different steps.

[0073] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs.

[0074] Those skilled in the art will understand that all or some of the steps in the methods disclosed above, as well as the functional modules / units in the systems and devices, can be implemented as software, firmware, hardware, or suitable combinations thereof.

[0075] The terms “first,” “second,” “third,” “fourth,” etc. (if present) in the specification and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms “comprising” and “having,” and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0076] It should be understood that in this application, "at least one (item)" means one or more, and "more than" means two or more. "And / or" is used to describe the relationship between related objects, indicating that three relationships can exist. For example, "A and / or B" can represent three cases: only A exists, only B exists, and both A and B exist simultaneously, where A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship. "At least one (item) of the following" or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one (item) of a, b, or c can represent: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, and c can be single or multiple.

[0077] In the several embodiments provided in this application, it should be understood that the disclosed apparatus and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of the units described above is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. The coupling or direct coupling or communication connection between the shown or discussed units may be through some interfaces, or indirect coupling or communication connection between the apparatus or units, and may be electrical, mechanical, or other forms.

[0078] The units described above as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0079] Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0080] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes multiple instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods of the various embodiments of this application. The aforementioned storage medium includes various media capable of storing programs, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0081] The preferred embodiments of the present application have been described above with reference to the accompanying drawings, but this does not limit the scope of the claims of the present application. Any modifications, equivalent substitutions, and improvements made by those skilled in the art without departing from the scope and substance of the embodiments of the present application shall be within the scope of the claims of the present application.

Claims

1. A flip-type phase-shifting transformer, characterized in that, include: Excitation winding unit, series winding unit, and bridge switching unit; The series winding unit is connected in series between the power supply side and the load side of the transmission line; The bridge-type switching unit includes a first switching branch and a second switching branch; One end of the first switching branch is connected to the power supply side, and the other end is connected to the power supply terminal of the excitation winding unit; one end of the second switching branch is connected to the load side, and the other end is connected to the power supply terminal of the excitation winding unit; the bridge switching unit is configured to switch between a first state and a second state: in the first state, the first switching branch is turned on so that the excitation winding unit and the power supply side form a first excitation circuit; in the second state, the second switching branch is turned on so that the excitation winding unit and the load side form a second excitation circuit.

2. The flip-type phase-shifting transformer according to claim 1, characterized in that, The transmission line is a three-phase line, and the excitation winding unit includes three excitation windings connected in parallel using a star connection, which correspond to the three phases of the three-phase line respectively. The series winding unit includes nine series windings; three series windings are connected in series on each phase of the three-phase line; for any phase line, the three series windings connected in series on that phase line are respectively coupled to the three excitation windings to generate compensation voltage components corresponding to different phases on that phase line.

3. The flip-type phase-shifting transformer according to claim 1, characterized in that, Both the first switching branch and the second switching branch are composed of anti-parallel thyristor groups; The first switching branch includes at least one set of first anti-parallel thyristors, which are connected between the power supply side and the power take-off terminal of the excitation winding unit. The second switching branch includes at least one set of second anti-parallel thyristors, which are connected between the load side and the power take-off terminal of the excitation winding unit. The flip-type phase-shifting transformer also includes a controller connected to the bridge switching unit, which controls the bridge switching unit to switch between the first state and the second state by triggering the conduction and cutoff of the anti-parallel thyristor group.

4. The flip-type phase-shifting transformer according to claim 3, characterized in that, The series winding unit is equipped with an on-load tap changer, which is used to adjust the ratio of the number of turns of the series winding connected to the transmission line.

5. A control method for a flip-type phase-shifting transformer, characterized in that, The method is applied to a controller for controlling a flip-type phase-shifting transformer as described in any one of claims 1 to 4, the method comprising: Obtain the power flow regulation target of the power system; Based on the power flow regulation target, the target operating state is determined from the first state and the second state; Send a switching control signal to the bridge switching unit to activate the first switching branch or the second switching branch, so that the flip-type phase-shifting transformer enters the target working state; The target tap of the series winding unit is determined according to the power flow regulation target, and the series winding unit is controlled to switch to the target tap to generate a target compensation voltage in the transmission line that satisfies the power flow regulation target.

6. The control method for the flip-type phase-shifting transformer according to claim 5, characterized in that, Determining the target operating state from the first state and the second state based on the power flow regulation target includes: Determine the initial adjustment range corresponding to the first state and the flip adjustment range corresponding to the second state; Determine whether the power flow regulation target is within the initial regulation range; if the power flow regulation target is within the initial regulation range, determine that the target's working state is the first state. If the current regulation target is outside the initial regulation range but within the flip regulation range, the target working state is determined to be the second state.

7. The control method for the flip-type phase-shifting transformer according to claim 5, characterized in that, Determining the target gear of the series winding unit based on the power flow regulation target includes: Based on the power flow regulation target, calculate the required active power regulation and reactive power regulation. Based on the active power adjustment and the reactive power adjustment, the voltage amplitude required for each phase component in the series winding unit is calculated. Under the target operating state, the gear combination of the series winding unit is matched according to the voltage amplitude required for each phase component, and the gear combination is determined as the target gear.

8. The control method for the flip-type phase-shifting transformer according to claim 5, characterized in that, Sending the switching control signal to the bridge switching unit includes: If the target operating state is the first state, a first trigger signal is sent to turn on the first switching branch connected between the power supply side and the excitation winding unit, and to turn off the second switching branch. If the target operating state is the second state, a second trigger signal is sent to turn on the second switching branch connected between the load side and the excitation winding unit, and the first switching branch is turned off, so as to use the load side voltage after superimposing the target compensation voltage as the excitation voltage.

9. A controller, characterized in that, The controller includes a memory and a processor. The memory stores a computer program, and the processor executes the computer program to implement the flip-type phase-shifting transformer control method according to any one of claims 5 to 8.

10. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by the processor, it implements the flip-type phase-shifting transformer control method according to any one of claims 5 to 8.

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