Loop closing transformer control method and system of dual-core asymmetric phase-shifting transformer

Abstract

The invention discloses a closed-loop transformer control method and system for a double-core asymmetric phase-shifting transformer, and relates to the technical field of closed-loop power supply of a 10KV power distribution network. The closed-loop transformer comprises a double-core asymmetric phase-shifting transformer bank and a voltage-regulating transformer bank; wherein the dual-core asymmetric phase-shifting transformer bank consists of an exciting transformer bank and a series transformer bank; adjusting the connection sequence and the connection direction of the primary side wiring terminals of the series transformer bank or adjusting the connection sequence and the connection direction of the secondary side wiring terminals in the dual-core asymmetric phase-shifting transformer; adjusting the number of actual access turns of a secondary side coil of an exciting transformer in the dual-core asymmetric phase-shifting transformer; reversing of the closed-loop transformer based on the dual-core asymmetric phase-shifting transformer is realized through a table look-up method, flexible adjustment and phase control of output voltage of the closed-loop transformer are realized, the problem of circulating current possibly occurring in closed-loop operation is effectively solved, and stability and reliability of power grid operation are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of 10KV distribution network closed-loop power transfer, and specifically to a control method and system for a closed-loop transformer of a dual-core asymmetric phase-shifting transformer. Background Technique

[0002] With the continuous development of the power system and the wide application of renewable energy, the complexity of the power grid and the requirements for flexibility and stability are getting higher and higher. As an important power system operation mode, closed-loop operation is used to achieve flexible dispatching of the power grid and optimize resource allocation. However, during the traditional closed-loop operation process, due to the differences in voltage phase and amplitude between the two sides of the power grid, circulating current is often generated, which not only increases power grid losses, but may also cause problems such as equipment overload and voltage fluctuations, seriously affecting the stability and reliability of the power grid.

[0003] To solve these problems, the phase-shifting transformer technology emerged. By changing the connection method or winding turns ratio of the transformer, the phase-shifting transformer can adjust the voltage phase, thereby reducing the circulating current during closed-loop operation. In practical applications, the phase-shifting angle error of traditional phase-shifting transformers is relatively large under full-load operation conditions, making it difficult to meet the requirements of high-precision regulation.

[0004] In recent years, dual-core symmetric phase-shifting transformers have gradually been applied to ultra-high voltage power grids, which have improved the regulation ability to a certain extent, but there are still problems such as limited regulation range and insufficient flexibility. At the same time, the regulation range and flexibility of single-core phase-shifting transformers are limited and cannot adapt to complex and changeable power grid operation conditions. These problems limit the application effect of phase-shifting transformers in modern power systems and also highlight the necessity of developing a new type of closed-loop transformer and its control method.

[0005] Therefore, the present invention proposes a closed-loop transformer based on a dual-core asymmetric phase-shifting transformer and its control method, aiming to achieve flexible regulation of the output voltage of the closed-loop transformer and phase control by optimizing the structural design and control strategy of the transformer, effectively solving the possible circulating current problems during closed-loop operation, and thus improving the stability and reliability of power grid operation. Summary of the Invention

[0006] In view of the existing problems above, the present invention is proposed.

[0007] Therefore, the technical problems solved by the present invention are: the existing control methods for dual-core symmetric phase-shifting transformers have limited phase-shifting angle adjustment range, insufficient adaptability to asymmetric conditions, low dynamic circulating current suppression accuracy, and the problem of how to achieve flexible regulation of the output voltage of the closed-loop transformer and phase control.

[0008] To solve the above technical problems, the present invention provides the following technical solutions: A control method for a closed-loop transformer of a dual-core asymmetric phase-shifting transformer, including adjusting the connection sequence and connection direction of the primary-side connection terminals of the series transformer group or adjusting the connection sequence and connection direction of the secondary-side connection terminals in the dual-core asymmetric phase-shifting transformer; adjusting the actual number of turns of the secondary-side coil of the excitation transformer in the dual-core asymmetric phase-shifting transformer; realizing the commutation of the closed-loop transformer based on the dual-core asymmetric phase-shifting transformer through a look-up table method

[0009] As a preferred solution of the control method for the closed-loop transformer of the dual-core asymmetric phase-shifting transformer of the present invention, wherein: The closed-loop transformer includes a dual-core asymmetric phase-shifting transformer group and a voltage regulating transformer group; The dual-core asymmetric phase-shifting transformer group includes an excitation transformer group and a series transformer group; The voltage regulating transformer group includes a voltage regulating transformer a-phase, a voltage regulating transformer b-phase, and a voltage regulating transformer c-phase; The excitation transformer group includes an excitation transformer a-phase, an excitation transformer b-phase, and an excitation transformer c-phase; The series transformer group includes a series transformer a-phase, a series transformer b-phase, and a series transformer c-phase

[0010] As a preferred solution of the control method for the closed-loop transformer of the dual-core asymmetric phase-shifting transformer of the present invention, wherein: The voltage regulating transformer group further includes a first connection terminal of the primary-side winding of the voltage regulating transformer a-phase connected to the output terminal U of the a-phase of the dual-core asymmetric phase-shifting transformer 1a and the second connection terminal is grounded; The first connection terminal of the secondary-side winding of the voltage regulating transformer a-phase is left open, and the wire is directly led out as the output terminal U of the a-phase of the closed-loop transformer La and the second connection terminal is grounded

[0011] The first connection terminal of the primary-side winding of the voltage regulating transformer b-phase is connected to the output terminal U of the b-phase of the dual-core asymmetric phase-shifting transformer 1b and the second connection terminal is grounded; The first connection terminal of the secondary-side winding of the voltage regulating transformer b-phase is left open, and the wire is directly led out as the output terminal U of the b-phase of the closed-loop transformer Lb and the second connection terminal is grounded

[0012] The first connection terminal of the primary-side winding of the voltage regulating transformer c-phase is connected to the output terminal U of the a-phase of the dual-core asymmetric phase-shifting transformer 1c and the second connection terminal is grounded; The first connection terminal of the secondary-side winding of the voltage regulating transformer c-phase is left open, and the wire is directly led out as the output terminal U of the c-phase of the closed-loop transformer Lc and the second connection terminal is grounded

[0013] The excitation transformer group further includes a first connection terminal of the primary-side winding of the excitation transformer a-phase connected to the a-phase power supply U Saare directly connected, and the second terminal is grounded; the first terminal of the secondary winding of phase a of the excitation transformer is connected to the first terminal of the secondary winding of phase c of the series transformer, and the second terminal is grounded; the first terminal of the primary winding of phase b of the excitation transformer is connected to the phase b power supply U Sb are directly connected, and the second terminal is grounded; the first terminal of the secondary winding of phase b of the excitation transformer is connected to the first terminal of the secondary winding of phase a of the series transformer, and the second terminal is grounded; the first terminal of the primary winding of phase c of the excitation transformer is connected to the phase c power supply U Sc are directly connected, and the second terminal is grounded; the first terminal of the secondary winding of phase c of the excitation transformer is connected to the first terminal of the secondary winding of phase b of the series transformer, and the second terminal is grounded; the series transformer group further includes the first terminal of the primary winding of phase a of the series transformer being connected to the phase a power supply U Sa are directly connected, and the second terminal serves as the output terminal U of phase a of the double-core asymmetric phase-shifting transformer 1a is connected to the first terminal of the primary winding of phase a of the voltage regulating transformer; the first terminal of the secondary winding of phase a of the series transformer is connected to the first terminal of the secondary winding of phase b of the excitation transformer, and the second terminal is connected to the first terminal of the secondary winding of phase c of the excitation transformer; the first terminal of the primary winding of phase b of the series transformer is connected to the phase b power supply U Sb are directly connected, and the second terminal serves as the output terminal U of phase b of the double-core asymmetric phase-shifting transformer 1b is connected to the first terminal of the primary winding of phase b of the voltage regulating transformer; the first terminal of the secondary winding of phase b of the series transformer is connected to the first terminal of the secondary winding of phase c of the excitation transformer, and the second terminal is connected to the first terminal of the secondary winding of phase a of the excitation transformer; the first terminal of the primary winding of phase c of the series transformer is connected to the phase c power supply U Sc are directly connected, and the second terminal serves as the output terminal U of phase c of the double-core asymmetric phase-shifting transformer 1c is connected to the first terminal of the primary winding of phase c of the voltage regulating transformer; the first terminal of the secondary winding of phase c of the series transformer is connected to the first terminal of the secondary winding of phase a of the excitation transformer, and the second terminal is connected to the first terminal of the secondary winding of phase b of the excitation transformer.

[0014] As a preferred solution of the closed-loop transformer control method of the double-core asymmetric phase-shifting transformer of the present invention, wherein: adjusting the connection sequence and connection direction of the primary terminals of the series transformer group includes using the first terminal of the primary winding of phase a of the series transformer as the output terminal U of phase a of the double-core asymmetric phase-shifting transformer 1a is connected to the first terminal of the primary winding of phase a of the voltage regulating transformer, and the second terminal is connected to the phase a power supply U SaAre directly connected; the first terminal of the primary winding of phase b of the series transformer serves as the output terminal U of phase b of the double-core asymmetric phase-shifting transformer 1b Is connected to the first terminal of the primary winding of phase b of the voltage regulating transformer, and the second terminal is directly connected to the phase b power supply U Sb Are directly connected; the first terminal of the primary winding of phase c of the series transformer serves as the output terminal U of phase c of the double-core asymmetric phase-shifting transformer 1c Is connected to the first terminal of the primary winding of phase c of the voltage regulating transformer, and the second terminal is directly connected to the phase c power supply U Sc Are directly connected.

[0015] As a preferred scheme of the closed-loop transformer control method of the double-core asymmetric phase-shifting transformer of the present invention, wherein: adjusting the connection sequence and connection direction of the secondary terminals in the double-core asymmetric phase-shifting transformer includes connecting the first terminal of the secondary winding of phase a of the series transformer to the first terminal of the secondary winding of phase b of the series transformer, and the second terminal is connected to the first terminal of the secondary winding of the excitation transformer of phase b; connecting the first terminal of the secondary winding of phase b of the series transformer to the first terminal of the secondary winding of phase c of the series transformer, and the second terminal is connected to the first terminal of the secondary winding of the excitation transformer of phase c; connecting the first terminal of the secondary winding of phase c of the series transformer to the first terminal of the secondary winding of phase a of the series transformer, and the second terminal is connected to the first terminal of the secondary winding of the excitation transformer of phase a.

[0016] As a preferred scheme of the closed-loop transformer control method of the double-core asymmetric phase-shifting transformer of the present invention, wherein: adjusting the actual number of turns of the secondary coil of the excitation transformer in the double-core asymmetric phase-shifting transformer includes that the actual number of turns of the secondary coil of the excitation transformer in the double-core asymmetric phase-shifting transformer are respectively the actual number of turns of the secondary coil of the excitation transformer in the double-core asymmetric phase-shifting transformer during the forward amplitude-phase adjustment of the closed-loop transformer; during the forward amplitude-phase adjustment, by describing the constraint relationship between the compensated voltage phasor output by the closed-loop transformer and the actual number of turns of the secondary coil of the excitation transformer, a system of equations is established; when three-phase symmetry is achieved, the equation set of phase a is expressed as:

[0017]

[0018] Wherein, k ET Represents the turns ratio of the excitation transformer, k ETa 、k ETb 、k ETc Respectively represent the primary and secondary turns ratios of phases a, b, and c in the excitation transformer, k ST Represents the turns ratio of the series transformer, k STa 、k STb 、k STcrespectively represent the primary and secondary turns ratios of phases a, b, and c in the series transformer, k T represents the turns ratio of the voltage regulating transformer, k Ta 、k Tb 、k Tc respectively represent the primary and secondary turns ratios of phases a, b, and c in the voltage regulating transformer, respectively represent the primary side voltages of phases a, b, and c of the excitation transformer, respectively represent the secondary side voltages of phases a, b, and c of the excitation transformer, respectively represent the power supply voltages of phases a, b, and c, respectively represent the secondary side voltages of phases a, b, and c of the series transformer, represents the output voltage of phase a of the double-core asymmetric phase-shifting transformer, represents the voltage at the output terminal of phase a of the closed-loop transformer, represents the phase angle difference, j represents the imaginary part; perform iterative calculations on the ideal access turn ratio of the secondary side coil of the excitation transformer to obtain the initial value of the primary and secondary turn ratios, and dynamically adjust the actual access number of turns of the secondary side coil of the excitation transformer.

[0019] As a preferred scheme of the closed-loop transformer control method for the double-core asymmetric phase-shifting transformer of the present invention, wherein: the commutation of the closed-loop transformer includes calculating the iterative value of the turns ratio of each phase secondary side winding coil of the excitation transformer in the double-core asymmetric phase-shifting transformer by the look-up table method; building a simulation model of the closed-loop transformer based on the double-core asymmetric phase-shifting transformer, setting the voltage vector difference on both sides of different closed-loop points, and using the iterative value of the turns ratio as the simulation parameter value to observe the simulation waveform or simulation data; comparing whether the two-norm of the difference between the simulation output voltage phasor and the theoretically calculated output voltage phasor is within the allowable error range; if the two-norm is within the allowable error range, it indicates that the theoretically deduced value is correct; if the two-norm is not within the allowable error range, it indicates that the equations are incorrect or the iterative calculated value is incorrect, and re-derivation or calculation is performed; if the theoretically deduced value is correct, record the corresponding simulation data in a table, and when the closed-loop transformer based on the double-core asymmetric phase-shifting transformer is actually put into operation, according to the voltage phasor difference detected in real time on both sides of the closed-loop point, select the best turns ratio data of each phase secondary side coil of the excitation transformer in the double-core asymmetric phase-shifting transformer by looking up the table, and dynamically adjust the actual access number of turns of each phase secondary side coil of the double-core asymmetric phase-shifting transformer.

[0020] Another object of the present invention is to provide a closed-loop transformer control system for a double-core asymmetric phase-shifting transformer, which can solve the technical problems of rigid regulation and lagging dynamic response in the current double-core symmetric phase-shifting transformer technology by constructing an asymmetric magnetic circuit topology and a voltage regulating transformer collaborative control architecture and dynamically optimizing the turns ratio of the excitation winding in combination with the look-up table method.

[0021] As a preferred solution of the closed-loop transformer control system of the dual-core asymmetric phase-shifting transformer described in the present invention, it includes: a transformer connection module, a turn number adjustment module, and a transformer control module;

[0022] The transformer connection module is used to adjust the connection sequence and direction of the primary-side wiring terminals of the series transformer group or adjust the connection sequence and direction of the secondary-side wiring terminals in the dual-core asymmetric phase-shifting transformer; the turn number adjustment module is used to adjust the actual number of turns of the secondary-side coil of the excitation transformer in the dual-core asymmetric phase-shifting transformer; the transformer control module is used to realize the commutation of the closed-loop transformer based on the dual-core asymmetric phase-shifting transformer through the look-up table method.

[0023] A computer device includes a memory and a processor. The memory stores a computer program, and the processor executes the computer program to implement the steps of the closed-loop transformer control method for the dual-core asymmetric phase-shifting transformer.

[0024] A computer-readable storage medium stores a computer program thereon. When the computer program is executed by a processor, it implements the steps of the closed-loop transformer control method for the dual-core asymmetric phase-shifting transformer.

[0025] The beneficial effects of the present invention: The closed-loop transformer control method for the dual-core asymmetric phase-shifting transformer provided by the present invention breaks the phase compensation direction limitation of the traditional dual-core symmetric structure through the asymmetric magnetic circuit design of the dual-core asymmetric phase-shifting transformer group, realizes multi-degree-of-freedom phase conditions, and the cross-coupling topology of the excitation transformer and the series transformer can generate orthogonal compensation components. Combined with the amplitude regulation of the voltage regulating transformer group, the phase-shift angle adjustment range is significantly expanded, and the problem of phase-shift accuracy decline caused by core saturation is avoided; through the dual-core asymmetric structure, each phase is allowed to independently adjust the amplitude and phase of the compensation vector, which can dynamically adapt to asymmetric operating scenarios such as three-phase load imbalance and voltage fluctuation in the distribution network. The cross-winding connection method of the series transformer group reduces the inter-phase harmonic coupling effect through magnetic circuit decoupling; through the dynamic control strategy based on the look-up table method, through the preset transformation ratio parameter library and the real-time voltage vector feedback mechanism, the rapid tracking and compensation of the voltage difference on both sides of the closed-loop point are realized, effectively avoiding the equipment overload risk caused by the lag of circulating current suppression; through the series design of the voltage regulating transformer group and the dual-core phase-shifting transformer, while ensuring the functional completeness, the use of additional power electronic devices is reduced, and the system complexity and cost are lowered. Description of the Drawings

[0026] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other accompanying drawings can be obtained based on these drawings.

[0027] Figure 1 It is the overall flowchart of the closed-loop transformer control method for a dual-core asymmetric phase-shifting transformer provided by the first embodiment of the present invention.

[0028] Figure 2 It is the topological structure diagram of the closed-loop transformer for the closed-loop transformer control method of a dual-core asymmetric phase-shifting transformer provided by the first embodiment of the present invention.

[0029] Figure 3 It is the input-output voltage vector relationship diagram when the closed-loop transformer of the closed-loop transformer control method for a dual-core asymmetric phase-shifting transformer provided by the first embodiment of the present invention is adjusted in the forward amplitude-phase.

[0030] Figure 4 It is the PSCAD simulation diagram of the closed-loop transformer for the closed-loop transformer control method of a dual-core asymmetric phase-shifting transformer provided by the second embodiment of the present invention.

[0031] Figure 5 It is the simulation waveform diagram of the a-phase voltage amplitude of the closed-loop transformer for the closed-loop transformer control method of a dual-core asymmetric phase-shifting transformer provided by the second embodiment of the present invention.

[0032] Figure 6 It is the simulation waveform diagram of the a-phase voltage phase angle of the closed-loop transformer for the closed-loop transformer control method of a dual-core asymmetric phase-shifting transformer provided by the second embodiment of the present invention.

[0033] Figure 7 It is the simulation waveform diagram of the a-phase line current of the closed-loop transformer for the closed-loop transformer control method of a dual-core asymmetric phase-shifting transformer provided by the second embodiment of the present invention.

[0034] Figure 8 It is the overall flowchart of the closed-loop transformer control system for a dual-core asymmetric phase-shifting transformer provided by the fourth embodiment of the present invention. Specific embodiments

[0035] To make the above objects, features, and advantages of the present invention more apparent and understandable, the following provides a detailed description of the specific embodiments of the present invention with reference to the accompanying drawings of the specification. Apparently, the described embodiments are only a part of the embodiments of the present invention, rather than all embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the scope of protection of the present invention.

[0036] Embodiment 1, referring to Figure 1 , which is an embodiment of the present invention, provides a control method for a closed-loop transformer of a dual-core asymmetric phase-shifting transformer, including:

[0037] S1: Adjust the connection sequence and connection direction of the primary-side connection terminals of the series transformer group or adjust the connection sequence and connection direction of the secondary-side connection terminals in the dual-core asymmetric phase-shifting transformer.

[0038] Furthermore, as Figure 2 shown, the closed-loop transformer includes a dual-core asymmetric phase-shifting transformer group and a voltage-regulating transformer group; the dual-core asymmetric phase-shifting transformer group includes an exciting transformer group and a series transformer group; the voltage-regulating transformer group includes a voltage-regulating transformer a-phase, a voltage-regulating transformer b-phase, and a voltage-regulating transformer c-phase; the exciting transformer group includes an exciting transformer a-phase, an exciting transformer b-phase, and an exciting transformer c-phase; the series transformer group includes a series transformer a-phase, a series transformer b-phase, and a series transformer c-phase.

[0039] It should be noted that the voltage-regulating transformer group also includes that the first connection terminal of the primary-side winding of the voltage-regulating transformer a-phase is connected to the output terminal U 1a of the a-phase of the dual-core asymmetric phase-shifting transformer, and the second connection terminal is grounded; the first connection terminal of the secondary-side winding of the voltage-regulating transformer a-phase is left open, and a wire is directly led out as the output terminal U La of the a-phase of the closed-loop transformer, and the second connection terminal is grounded; the first connection terminal of the primary-side winding of the voltage-regulating transformer b-phase is connected to the output terminal U 1b of the b-phase of the dual-core asymmetric phase-shifting transformer, and the second connection terminal is grounded; the first connection terminal of the secondary-side winding of the voltage-regulating transformer b-phase is left open, and a wire is directly led out as the output terminal U Lb of the b-phase of the closed-loop transformer, and the second connection terminal is grounded; the first connection terminal of the primary-side winding of the voltage-regulating transformer c-phase is connected to the output terminal U 1c of the a-phase of the dual-core asymmetric phase-shifting transformer, and the second connection terminal is grounded; the first connection terminal of the secondary-side winding of the voltage-regulating transformer c-phase is left open, and a wire is directly led out as the output terminal U Lc of the c-phase of the closed-loop transformer, and the second connection terminal is grounded.

[0040] The exciting transformer group also includes that the first connection terminal of the primary-side winding of the exciting transformer a-phase is connected to the a-phase power supply U Saare directly connected, and the second terminal is grounded; the first terminal of the secondary winding of phase a of the excitation transformer is connected to the first terminal of the secondary winding of phase c of the series transformer, and the second terminal is grounded; the first terminal of the primary winding of phase b of the excitation transformer is connected to the phase b power supply U Sb are directly connected, and the second terminal is grounded; the first terminal of the secondary winding of phase b of the excitation transformer is connected to the first terminal of the secondary winding of phase a of the series transformer, and the second terminal is grounded; the first terminal of the primary winding of phase c of the excitation transformer is connected to the phase c power supply U Sc are directly connected, and the second terminal is grounded; the first terminal of the secondary winding of phase c of the excitation transformer is connected to the first terminal of the secondary winding of phase b of the series transformer, and the second terminal is grounded.

[0041] The series transformer group also includes that the first terminal of the primary winding of phase a of the series transformer is connected to the phase a power supply U Sa are directly connected, and the second terminal serves as the output terminal U of phase a of the dual-core asymmetric phase-shifting transformer 1a and is connected to the first terminal of the primary winding of phase a of the voltage regulating transformer; the first terminal of the secondary winding of phase a of the series transformer is connected to the first terminal of the secondary winding of phase b of the excitation transformer, and the second terminal is connected to the first terminal of the secondary winding of phase c of the excitation transformer; the first terminal of the primary winding of phase b of the series transformer is connected to the phase b power supply U Sb are directly connected, and the second terminal serves as the output terminal U of phase b of the dual-core asymmetric phase-shifting transformer 1b and is connected to the first terminal of the primary winding of phase b of the voltage regulating transformer; the first terminal of the secondary winding of phase b of the series transformer is connected to the first terminal of the secondary winding of phase c of the excitation transformer, and the second terminal is connected to the first terminal of the secondary winding of phase a of the excitation transformer; the first terminal of the primary winding of phase c of the series transformer is connected to the phase c power supply U Sc are directly connected, and the second terminal serves as the output terminal U of phase c of the dual-core asymmetric phase-shifting transformer 1c and is connected to the first terminal of the primary winding of phase c of the voltage regulating transformer; the first terminal of the secondary winding of phase c of the series transformer is connected to the first terminal of the secondary winding of phase a of the excitation transformer, and the second terminal is connected to the first terminal of the secondary winding of phase b of the excitation transformer.

[0042] It should also be noted that adjusting the connection sequence and connection direction of the primary terminals of the series transformer group includes using the first terminal of the primary winding of phase a of the series transformer as the output terminal U of phase a of the dual-core asymmetric phase-shifting transformer 1a and connecting it to the first terminal of the primary winding of phase a of the voltage regulating transformer, and the second terminal is connected to the phase a power supply U Sa are directly connected.

[0043] The first terminal of the primary winding of phase b of the series transformer is used as the output terminal U of phase b of the double-core asymmetric phase-shifting transformer 1b It is connected to the first terminal of the primary winding of phase b of the voltage regulating transformer, and the second terminal is directly connected to the phase b power supply U Sb Directly connected.

[0044] The first terminal of the primary winding of phase c of the series transformer is used as the output terminal U of phase c of the double-core asymmetric phase-shifting transformer 1c It is connected to the first terminal of the primary winding of phase c of the voltage regulating transformer, and the second terminal is directly connected to the phase c power supply U Sc Directly connected.

[0045] It should also be noted that adjusting the connection sequence and direction of the secondary terminals in the double-core asymmetric phase-shifting transformer includes connecting the first terminal of the secondary winding of phase a of the series transformer to the first terminal of the secondary winding of phase b of the series transformer, and the second terminal to the first terminal of the secondary winding of the excitation transformer of phase b.

[0046] The first terminal of the secondary winding of phase b of the series transformer is connected to the first terminal of the secondary winding of phase c of the series transformer, and the second terminal is connected to the first terminal of the secondary winding of the excitation transformer of phase c.

[0047] The first terminal of the secondary winding of phase c of the series transformer is connected to the first terminal of the secondary winding of phase a of the series transformer, and the second terminal is connected to the first terminal of the secondary winding of the excitation transformer of phase a.

[0048] It should also be noted that by adjusting the connection sequence and direction of the primary side of the series transformer group or the secondary terminals of the double-core asymmetric phase-shifting transformer, the magnetic circuit symmetry limitation of the traditional double-core symmetric structure is broken, and an asymmetric magnetic circuit coupling relationship is constructed. This design makes the phase adjustment direction of each phase compensation vector independently controllable. Through the cross-winding connection, the phase-shift angle adjustment range is significantly expanded, and the problem of single-phase compensation direction of the traditional symmetric structure is solved; by the phasors of the secondary sides of phase a and phase b of the series transformer, the inter-phase harmonic coupling effect is reduced through magnetic circuit decoupling, and the power quality of the power grid is improved.

[0049] S2: Adjust the actual number of turns of the secondary coil of the excitation transformer in the double-core asymmetric phase-shifting transformer.

[0050] Further, adjusting the actual number of turns of the secondary side coil of the exciting transformer in the dual-core asymmetric phase-shifting transformer includes that the actual number of turns of the secondary side coil of the exciting transformer in the dual-core asymmetric phase-shifting transformer are respectively the actual number of turns of the secondary side coil of the exciting transformer in the dual-core asymmetric phase-shifting transformer during the positive amplitude-phase regulation of the closed-loop transformer; during the positive amplitude-phase regulation, by describing the constraint relationship between the compensated voltage phasor output by the closed-loop transformer and the actual number of turns of the secondary side coil of the exciting transformer, a system of equations is established; since the three phases of the closed-loop transformer operate symmetrically, only one phase needs to be analyzed, and in this embodiment of the present application, phase a is taken as an example;

[0051] When the three phases are symmetrical, the system of equations for phase a is expressed as:

[0052]

[0053] Among them, k ET represents the turns ratio of the exciting transformer, k ETa , k ETb , k ETc respectively represent the primary-secondary turns ratios of phases a, b, and c in the exciting transformer, k ST represents the turns ratio of the series transformer, k STa , k STb , k STc respectively represent the primary-secondary turns ratios of phases a, b, and c in the series transformer, k T represents the turns ratio of the voltage regulating transformer, k Ta , k Tb , k Tc respectively represent the primary-secondary turns ratios of phases a, b, and c in the voltage regulating transformer, respectively represent the primary side voltages of phases a, b, and c of the exciting transformer, respectively represent the secondary side voltages of phases a, b, and c of the exciting transformer, respectively represent the power supply voltages of phases a, b, and c, respectively represent the secondary side voltages of phases a, b, and c of the series transformer, represents the output voltage of phase a of the dual-core asymmetric phase-shifting transformer, represents the voltage at the output terminal of phase a of the closed-loop transformer, represents the phase angle difference, and j represents the imaginary part; iterative calculation is performed on the ideal number of turns ratio of the secondary side coil of the exciting transformer to obtain the initial value of the primary-secondary turns ratio, and the actual number of turns of the secondary side coil of the exciting transformer is dynamically adjusted.

[0054] It should be noted that when the three phases are symmetrical, the vector relationship between the compensated voltage phasors of each phase and the input-output voltage phasors of each phase is as Figure 3As shown in the figure, the closed-loop transformer is in positive amplitude-phase regulation. Taking phase a as an example, the voltage compensation phasor perpendicular to the output of phase a of the double-core asymmetric phase-shifting transformer is output. Through the primary-secondary turns ratio of the double-core asymmetric phase-shifting transformer, the voltage compensation phasor is used as the output of the double-core asymmetric phase-shifting transformer and connected to the voltage regulating transformer. Then, the voltage regulating transformer transforms the amplitude of the voltage compensation phasor of the double-core asymmetric phase-shifting transformer, thereby realizing the adjustment of the amplitude-phase value of the output voltage U at the phase a output end of the closed-loop transformer based on the double-core asymmetric phase-shifting transformer. La Adjustment of the amplitude-phase value.

[0055] It should also be noted that by dynamically adjusting the actual number of turns of the secondary side coil of the excitation transformer and iteratively calculating the ideal turns ratio combined with the established equations, the precise matching of the amplitude and phase of the compensation voltage phasor is achieved. For example, in the case of three-phase symmetry, the turns ratio parameters are dynamically optimized through the phase a equations to ensure the minimization of the two-norm of the error between the output voltage vector and the actual expected value, significantly improving the adjustment accuracy.

[0056] S3: Realize the commutation of the closed-loop transformer based on the double-core asymmetric phase-shifting transformer through the look-up table method.

[0057] Furthermore, the commutation of the closed-loop transformer includes calculating the iterative value of the turns ratio of the secondary side winding coils of each phase of the excitation transformer in the double-core asymmetric phase-shifting transformer through the look-up table method; building a simulation model of the closed-loop transformer based on the double-core asymmetric phase-shifting transformer, setting the voltage vector difference on both sides of different closed-loop points, and using the iterative value of the turns ratio as the simulation parameter value to observe the simulation waveform or simulation data; comparing whether the two-norm of the difference between the simulation output voltage phasor and the theoretically calculated output voltage phasor is within the allowable error range; if the two-norm is within the allowable error range, it indicates that the theoretically deduced value is correct; if the two-norm is not within the allowable error range, it indicates that the equations are incorrect or the iterative calculated value is incorrect, and re-derivation or calculation is required; if the theoretically deduced value is correct, record the corresponding simulation data in the table. When the closed-loop transformer based on the double-core asymmetric phase-shifting transformer is actually put into operation, according to the voltage phasor difference on both sides of the closed-loop point detected in real time, select the optimal turns ratio data of the secondary side coils of each phase of the excitation transformer in the double-core asymmetric phase-shifting transformer through look-up table, and dynamically adjust the actual number of turns of the secondary side coils of each phase of the double-core asymmetric phase-shifting transformer.

[0058] It should be noted that through the preset turns ratio parameter library and combining with the voltage phasor difference on both sides of the closed-loop point detected in real time, the look-up table difference quickly matches the optimal turns ratio data, shortening the dynamic response time to the millisecond level. Compared with the traditional open-loop control or iterative calculation, it improves the efficiency of circulating current suppression and avoids the risk of equipment overload.

[0059] It should also be noted that by verifying the correctness of the theoretically derived values through the simulation model, ensuring the accuracy of the parameter library, directly calling the pre-stored data during actual operation to reduce the online calculation complexity, reducing the dependence on high-performance processors, and at the same time enhancing the anti-interference ability of the system.

[0060] Example 2, referring to Figures 4 - 7 , is an embodiment of the present invention, which provides a method for load balancing of a computing platform based on the particle swarm genetic algorithm. In order to verify the beneficial effects of the present invention, scientific demonstrations are carried out through economic benefit calculations and simulation experiments.

[0061] To verify the effectiveness of the method of the present invention, the following set of transformation ratio examples are provided: The set values of the closed-loop parameters and the theoretically calculated values of some parameters are shown in the first column and the second column of Table 1.

[0062] Table 1 Parameter settings and simulation data table of the flexible closed-loop device

[0063]

[0064]

[0065] Among them, represents the effective value of the voltage at the output terminal of phase a of the closed-loop transformer, represents the effective value of the phase a power supply, represents the effective value of the phase a line current.

[0066] Build a transformer model as shown in Figure 4 in PSCAD, and obtain the simulation waveform of the amplitude of the output voltage of phase a of the closed-loop transformer based on the dual-core asymmetric phase-shifting transformer as shown in Figure 5 . The verification formula is expressed as:

[0067]

[0068] Among them, u La,p represents the peak value of the phase a voltage.

[0069] Obtain the simulation waveform of the phase angle of the output voltage of phase a of the closed-loop transformer based on the dual-core asymmetric phase-shifting transformer as shown in Figure 6 ; The simulation waveform of the phase a line current of the closed-loop transformer based on the dual-core asymmetric phase-shifting transformer as shown in Figure 7 .

[0070] The errors between the simulation data and the theoretically derived values are all within the allowable range, and the theoretical values of a set of transformation ratios of the secondary side coils of each phase of the dual-core asymmetric phase-shifting transformer are calculated correctly. Record the corresponding data in Table 1.

[0071] From Figure 5From the simulation waveforms, it can be seen that the voltage adjustment is completed within 1-2 cycles. Compared with traditional open-loop control or iterative calculation, the efficiency of circulating current suppression is significantly improved. From the fact that the errors between the simulation data and the theoretically derived values are all within the allowable range, it can be seen that the method of the present invention improves the adjustment accuracy. And through the look-up table method, directly calling the pre-stored data during actual operation reduces the online calculation complexity, reduces the dependence on high-performance processors, and improves the anti-interference ability of the system.

[0072] Embodiment 3 is the third embodiment of the present invention. What is different from the previous two embodiments is that:

[0073] If the above functions are implemented in the form of software function units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that makes a contribution to the prior art, or a part of this technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in various embodiments of the present invention. The aforementioned storage medium includes: various media such as USB flash drives, mobile hard disks, read-only memories (ROM, Read-Only Memory), random access memories (RAM, Random Access Memory), magnetic disks, or optical discs that can store program codes.

[0074] The logic and / or steps represented in the flowchart or described in other ways herein, for example, can be considered as a definite sequence list of executable instructions for implementing logical functions, and can be specifically implemented in any computer-readable medium for use by an instruction execution system, apparatus, or device (such as a computer-based system, a system including a processor, or other systems that can fetch instructions from the instruction execution system, apparatus, or device and execute the instructions), or used in combination with these instruction execution systems, apparatuses, or devices. For the purposes of this specification, a "computer-readable medium" can be any device that can contain, store, communicate, propagate, or transmit a program for use by or in connection with an instruction execution system, apparatus, or device.

[0075] More specific examples (non-exhaustive list) of computer-readable media include the following: electrical connections (electronic devices) having one or more wirings, portable computer disk cartridges (magnetic devices), random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber devices, and portable compact disc read-only memory (CDROM). Additionally, the computer-readable media can even be paper or other suitable media on which the program can be printed, because the program can be obtained electronically, for example, by optically scanning the paper or other media, then editing, interpreting, or otherwise processing it as appropriate, and then storing it in a computer memory.

[0076] It should be understood that the various parts of the present invention can be implemented using hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented using software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented using hardware, as in another embodiment, any one or a combination of the following techniques well known in the art can be used: discrete logic circuits having logic gate circuits for implementing logical functions on data signals, application specific integrated circuits having appropriate combinational logic gate circuits, programmable gate arrays (PGA), field programmable gate arrays (FPGA), etc.

[0077] Example 4, referring to Figure 8 , is the fourth embodiment of the present invention. This embodiment provides a system for a closed-loop transformer control method of a two-core asymmetric phase-shifting transformer, including.

[0078] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not limiting. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the spirit and scope of the technical solutions of the present invention, and they should all be covered by the scope of the claims of the present invention.

Claims

1. A control method for a closed-loop transformer of a dual-core asymmetric phase-shifting transformer, characterized in that, Including: Adjusting the connection sequence and direction of the primary side connection terminals of the series transformer bank, or adjusting the connection sequence and direction of the secondary side connection terminals in the dual-core asymmetric phase-shifting transformer; Adjusting the actual number of turns of the secondary side coil of the exciting transformer in the dual-core asymmetric phase-shifting transformer; Realizing the commutation of the closed-loop transformer based on the dual-core asymmetric phase-shifting transformer by the look-up table method.

2. The closed-loop transformer control method for the dual-core asymmetric phase-shifting transformer according to claim 1, characterized in that: The closed-loop transformer includes a dual-core asymmetric phase-shifting transformer bank and a voltage regulating transformer bank; The dual-core asymmetric phase-shifting transformer bank includes an exciting transformer bank and a series transformer bank; The voltage regulating transformer bank includes a voltage regulating transformer phase a, a voltage regulating transformer phase b, and a voltage regulating transformer phase c; The exciting transformer bank includes an exciting transformer phase a, an exciting transformer phase b, and an exciting transformer phase c; The series transformer bank includes a series transformer phase a, a series transformer phase b, and a series transformer phase c.

3. The closed-loop transformer control method of the dual-core asymmetric phase-shifting transformer according to claim 2, characterized in that: The voltage regulating transformer bank further includes that the first connection terminal of the primary side winding of the a-phase of the voltage regulating transformer is connected to the output terminal U of the a-phase of the double-core asymmetric phase-shifting transformer, and the second connection terminal is grounded; the first connection terminal of the secondary side winding of the a-phase of the voltage regulating transformer is left open, and a wire is directly led out as the output terminal U of the a-phase of the closed-loop transformer 1a ; the second connection terminal is grounded; La the second connection terminal is grounded. The first wiring terminal of the primary side winding of the voltage regulating transformer in phase b is connected to the output terminal U of the phase b of the double-core asymmetric phase-shifting transformer 1b and the second wiring terminal is grounded; the first wiring terminal of the secondary side winding of the voltage regulating transformer in phase b is left open and the wire is directly led out as the output terminal U of the phase b of the closed-loop transformer Lb and the second wiring terminal is grounded; The first wiring terminal of the primary side winding of the voltage regulating transformer in phase c is connected to the output terminal U of phase a of the double-core asymmetric phase-shifting transformer 1c and the second wiring terminal is grounded; the first wiring terminal of the secondary side winding of the voltage regulating transformer in phase c is left open and the wire is directly led out as the output terminal U of phase c of the closed-loop transformer Lc and the second wiring terminal is grounded; The excitation transformer bank further includes that the first terminal of the primary winding of the a-phase of the excitation transformer is directly connected to the a-phase power supply U Sa and the second terminal is grounded; the first terminal of the secondary winding of the a-phase of the excitation transformer is connected to the first terminal of the secondary winding of the c-phase of the series transformer, and the second terminal is grounded; The first terminal of the primary side winding of the excitation transformer's phase b is directly connected to the phase b power supply U Sb and the second terminal is grounded; the first terminal of the secondary side winding of the excitation transformer's phase b is connected to the first terminal of the secondary side winding of the series transformer's phase a, and the second terminal is grounded; The first terminal of the primary side winding of the exciting transformer in phase c is directly connected to the phase c power supply U Sc and the second terminal is grounded; the first terminal of the secondary side winding of the exciting transformer in phase c is connected to the first terminal of the secondary side winding of the series transformer in phase b, and the second terminal is grounded; The series transformer bank further includes a first connection terminal of the primary side winding of phase a of the series transformer directly connected to the phase a power supply U Sa and a second connection terminal serves as the output terminal U of phase a of the dual-core asymmetric phase-shifting transformer 1a connected to the first connection terminal of the primary side winding of phase a of the voltage regulating transformer; the first connection terminal of the secondary side winding of phase a of the series transformer is connected to the first connection terminal of the secondary side winding of phase b of the excitation transformer, and the second connection terminal is connected to the first connection terminal of the secondary side winding of phase c of the excitation transformer; The first terminal of the primary winding of phase b of the series transformer is directly connected to the phase b power supply U Sb The second terminal serves as the output terminal U of phase b of the dual-core asymmetric phase-shifting transformer 1b and is connected to the first terminal of the primary winding of phase b of the voltage regulating transformer; the first terminal of the secondary winding of phase b of the series transformer is connected to the first terminal of the secondary winding of phase c of the exciting transformer, and the second terminal is connected to the first terminal of the secondary winding of phase a of the exciting transformer; The first terminal of the primary winding of the series transformer in phase c is directly connected to the phase c power supply U Sc The second terminal serves as the output terminal U of the phase c of the double-core asymmetric phase-shifting transformer 1c and is connected to the first terminal of the primary winding of the phase c of the voltage regulating transformer; the first terminal of the secondary winding of the series transformer in phase c is connected to the first terminal of the secondary winding of the exciting transformer in phase a, and the second terminal is connected to the first terminal of the secondary winding of the exciting transformer in phase b.

4. The closed-loop transformer control method for the dual-core asymmetric phase-shifting transformer according to claim 3, characterized in that: The connection sequence and connection direction of the primary side wiring terminals of the adjusted series transformer bank include that the first wiring terminal of the a-phase primary side winding of the series transformer is used as the output terminal U of the a-phase of the double-core asymmetric phase-shifting transformer 1a is connected to the first wiring terminal of the a-phase primary side winding of the voltage regulating transformer, and the second wiring terminal is directly connected to the a-phase power supply U Sa directly; The first terminal of the primary winding of the series transformer in phase b serves as the output terminal U of the double-core asymmetric phase-shifting transformer in phase b. 1b It is connected to the first terminal of the primary winding of the voltage regulating transformer in phase b, and the second terminal is directly connected to the phase b power supply U. Sb Connected directly; The first terminal of the primary winding of the series transformer in phase c serves as the output terminal U of the double-core asymmetric phase-shifting transformer in phase c 1c is connected to the first terminal of the primary winding of the voltage regulating transformer in phase c, and the second terminal is directly connected to the phase c power supply U Sc directly.

5. The closed-loop transformer control method of the dual-core asymmetric phase-shifting transformer according to claim 4, characterized in that: The adjustment of the connection sequence and direction of the secondary side connection terminals in the dual-core asymmetric phase-shifting transformer includes connecting the first connection terminal of the secondary side winding of the series transformer phase a to the first connection terminal of the secondary side winding of the series transformer phase b, and the second connection terminal to the first connection terminal of the secondary side winding of the exciting transformer phase b; Connecting the first connection terminal of the secondary side winding of the series transformer phase b to the first connection terminal of the secondary side winding of the series transformer phase c, and the second connection terminal to the first connection terminal of the secondary side winding of the exciting transformer phase c; Connecting the first connection terminal of the secondary side winding of the series transformer phase c to the first connection terminal of the secondary side winding of the series transformer phase a, and the second connection terminal to the first connection terminal of the secondary side winding of the exciting transformer phase a.

6. The closed-loop transformer control method for the dual-core asymmetric phase-shifting transformer according to claim 5, characterized in that: The adjustment of the actual number of turns of the secondary side coil of the exciting transformer in the dual-core asymmetric phase-shifting transformer includes that the actual number of turns of the secondary side coil of the exciting transformer in the dual-core asymmetric phase-shifting transformer are respectively the actual number of turns of the secondary side coil of the exciting transformer in the dual-core asymmetric phase-shifting transformer during the positive amplitude-phase adjustment of the closed-loop transformer; During the positive amplitude-phase adjustment, by describing the constraint relationship between the compensated voltage phasor output by the closed-loop transformer and the actual number of turns of the secondary side coil of the exciting transformer, establishing a system of equations; When three-phase symmetry, the equation set of phase a is expressed as: Among them, k ET represents the turns ratio of the excitation transformer, k ETa , k ETb , k ETc respectively represent the primary and secondary turns ratios of phases a, b, and c in the excitation transformer, k ST represents the turns ratio of the series transformer, k STa , k STb , k STc respectively represent the primary and secondary turns ratios of phases a, b, and c in the series transformer, k T represents the turns ratio of the voltage regulating transformer, k Ta , k Tb , k Tc respectively represent the primary and secondary turns ratios of phases a, b, and c in the voltage regulating transformer, respectively represent the primary side voltages of phases a, b, and c of the excitation transformer, respectively represent the secondary side voltages of phases a, b, and c of the excitation transformer, respectively represent the power supply voltages of phases a, b, and c, respectively represent the secondary side voltages of phases a, b, and c of the series transformer, represents the output voltage of phase a of the double-core asymmetric phase-shifting transformer, represents the voltage at the output terminal of phase a of the loop-closing transformer, represents the phase angle difference, and j represents the imaginary part; Performing iterative calculation on the ideal turn ratio of the secondary side coil of the exciting transformer to obtain the initial value of the primary-secondary turn ratio, and dynamically adjusting the actual number of turns of the secondary side coil of the exciting transformer.

7. The closed-loop transformer control method of the dual-core asymmetric phase-shifting transformer according to claim 6, characterized in that: The commutation of the closed-loop transformer includes calculating the iterative value of the turns ratio of the secondary side winding coils of each phase of the exciting transformer in the dual-core asymmetric phase-shifting transformer by the look-up table method; Building a simulation model of the closed-loop transformer based on the dual-core asymmetric phase-shifting transformer, setting the voltage vector difference on both sides of different closed-loop points, and using the iterative value of the turns ratio as the simulation parameter value to observe the simulation waveform or simulation data; Comparing whether the two-norm of the difference between the simulated output voltage phasor and the theoretically calculated output voltage phasor is within the allowable error range; If the two-norm is within the allowable error range, it indicates that the theoretically deduced value is correct; If the two-norm is not within the allowable error range, it indicates that the equation set is incorrect or the iterative calculated value is incorrect, and re-derivation or calculation is performed. If the theoretically derived value is correct, record the corresponding simulation data in a table. When the closed-loop transformer based on the dual-core asymmetric phase-shifting transformer is actually put into operation, according to the phase difference of the voltage phasors on both sides of the closed-loop point detected in real time, select the turn ratio data of the secondary side coils of each phase of the excitation transformer in the best dual-core asymmetric phase-shifting transformer by looking up the table, and dynamically adjust the actual number of turns connected to the secondary side coils of each phase of the dual-core asymmetric phase-shifting transformer.

8. A system for a closed-loop transformer control method using a dual-core asymmetric phase-shifting transformer as described in any one of claims 1 to 7, characterized in that: It includes a transformer connection module, a turn number adjustment module, and a transformer control module; The transformer connection module is used to adjust the connection sequence and connection direction of the primary side wiring terminals of the series transformer group or adjust the connection sequence and connection direction of the secondary side wiring terminals in the dual-core asymmetric phase-shifting transformer; The turn number adjustment module is used to adjust the actual number of turns connected to the secondary side coil of the excitation transformer in the dual-core asymmetric phase-shifting transformer; The transformer control module is used to realize the commutation of the closed-loop transformer based on the dual-core asymmetric phase-shifting transformer by the look-up table method.

9. A computer device, comprising a memory and a processor, the memory storing a computer program, characterized in that, When the processor executes the computer program, it implements the steps of the closed-loop transformer control method of the dual-core asymmetric phase-shifting transformer according to any one of claims 1 to 7.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the steps of the closed-loop transformer control method of the dual-core asymmetric phase-shifting transformer according to any one of claims 1 to 7.

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