A method and system for obtaining transformer ratio based on power flow coupling characteristics

Abstract

The present invention discloses a transformer ratio acquisition method and system based on power flow coupling characteristics, and relates to the technical field of power systems. The method includes: determining equivalent circuit parameters and transformer parameters according to equipment information and power grid data of a transformer to be adjusted, and then determining the high-voltage side voltage in combination with real-time measurement data of the line where the transformer to be adjusted is located, real-time measurement data of the low-voltage side, and the current iterative ratio value, and further determining the current updated ratio value, using it as the current iterative ratio value, and re-executing the steps for determining the high-voltage side voltage until the error between the current updated ratio value and the current iterative ratio value meets the preset accuracy requirement, and using the current updated ratio value as the target ratio value of the transformer to be adjusted, so as to adjust the ratio of the transformer to be adjusted according to the target ratio value and the target distribution network voltage. The present invention improves the efficiency of obtaining transformer ratio information, and can meet the real-time requirements of distribution network voltage regulation for transformer ratio information.

Description

Technical Field

[0001] The present invention relates to the technical field of power systems, and in particular to a method and system for obtaining a transformer ratio based on power flow coupling characteristics. Background Art

[0002] During the operation of the power system, the distribution transformer is an important device connecting the 10 kV power line. The accurate acquisition of its transformation ratio is of vital importance to ensure the safe and stable operation of the power grid. For example, when the voltage level exceeds the limit due to low load in winter, it is necessary to obtain the real-time distribution transformer transformation ratio to achieve effective regulation of the voltage level. Generally speaking, the transformation ratio of the distribution transformer will be dynamically adjusted based on different power supply guarantee requirements, and the adjustment results are generally not uploaded to the equipment ledger, resulting in the distribution transformer transformation ratio recorded in the equipment ledger cannot be updated in time, and the regulation accuracy of the distribution network voltage cannot be ensured.

[0003] In order to obtain the transformation ratio of the distribution transformer, the existing technology usually requires the installation of additional transformation ratio metering equipment, and requires manual on-site measurement and reporting, which results in a long time required to obtain the transformer transformation ratio and cannot meet the real-time requirements of the distribution network voltage regulation for the transformer transformation ratio information. Summary of the invention

[0004] The present invention provides a transformer ratio acquisition method and system based on power flow coupling characteristics to solve the technical problems that the prior art takes a long time to acquire the distribution transformer ratio and cannot meet the real-time requirements of the distribution network voltage regulation for the transformer ratio information.

[0005] In order to solve the above technical problems, a first aspect of an embodiment of the present invention provides a method for obtaining a transformer ratio based on power flow coupling characteristics, comprising:

[0006] Determine the equivalent circuit parameters and transformer parameters corresponding to the transformer to be adjusted according to the equipment information and power grid data of the transformer to be adjusted;

[0007] Determine the high-voltage side voltage of the transformer to be adjusted according to the real-time measurement data of the line where the transformer to be adjusted is located, the real-time measurement data of the low-voltage side of the transformer to be adjusted, the current iterative transformation ratio value, the equivalent circuit parameters and the transformer parameters; wherein the initial value of the current iterative transformation ratio value is a preset standard transformation ratio value;

[0008] Determine a current updated transformation ratio value according to the high voltage side voltage and the low voltage side real-time measurement data;

[0009] The currently updated transformation ratio value is used as the current iterative transformation ratio value, and the steps for determining the high-voltage side voltage are re-executed until the error between the currently updated transformation ratio value and the current iterative transformation ratio value meets the preset accuracy requirement, and the currently updated transformation ratio value is used as the target transformation ratio value of the transformer to be adjusted, so as to adjust the transformation ratio of the transformer to be adjusted according to the target transformation ratio value and the target distribution network voltage to be adjusted.

[0010] As a preferred solution, determining the equivalent circuit parameters and transformer parameters corresponding to the transformer to be adjusted according to the equipment information and power grid data of the transformer to be adjusted specifically includes:

[0011] According to the equipment information of the transformer to be adjusted, the rated capacity, rated high-voltage side voltage, no-load loss, no-load current percentage, short-circuit loss and short-circuit voltage percentage of the transformer to be adjusted are obtained;

[0012] According to the rated capacity, the rated high-voltage side voltage, the no-load loss, the no-load current percentage, the short-circuit loss and the short-circuit voltage percentage, respectively determine the transformer resistance, transformer reactance and transformer excitation power, and use the transformer resistance, transformer reactance and transformer excitation power as the transformer parameters;

[0013] Determining a circuit topology structure corresponding to the transformer to be adjusted according to the power grid data;

[0014] According to the preset unit distance resistance, unit distance reactance, unit distance susceptance of the line, the length of the main line in the circuit topology structure and the length of the branch line where the transformer to be adjusted is located, the equivalent resistance, equivalent reactance and equivalent susceptance of the main line and the branch line are determined respectively, and the equivalent resistance, the equivalent reactance and the equivalent susceptance are used as the equivalent circuit parameters.

[0015] As a preferred solution, the transformer resistance, transformer reactance and transformer excitation power are determined respectively according to the rated capacity, the rated high-voltage side voltage, the no-load loss, the no-load current percentage, the short-circuit loss and the short-circuit voltage percentage, specifically including:

[0016] According to the short-circuit loss, the rated high-voltage side voltage and the rated capacity, the transformer resistance is determined by the following expression:

[0017] ;

[0018] According to the no-load loss, the no-load current percentage and the rated capacity, the transformer excitation power is determined by the following expression:

[0019] ;

[0020] According to the short-circuit voltage percentage, the rated high-voltage side voltage and the rated capacity, the transformer reactance is determined by the following expression;

[0021] ;

[0022] in, represents the transformer resistance; represents the transformer excitation power; represents the transformer reactance; Indicates the rated capacity; Indicates the rated high voltage side voltage; represents the no-load loss; Indicates the no-load current percentage; represents the short-circuit loss; Indicates the short-circuit voltage percentage.

[0023] As a preferred solution, the high-voltage side voltage of the transformer to be adjusted is determined according to the real-time measurement data of the line where the transformer to be adjusted is located, the real-time measurement data of the low-voltage side of the transformer to be adjusted, the current iterative transformation ratio, the equivalent circuit parameters and the transformer parameters, specifically including:

[0024] According to the real-time measurement data of the line where the transformer to be adjusted is located, the real-time power supply voltage, the real-time power supply active power and the real-time power supply reactive power are obtained;

[0025] Determine the input voltage of the branch line where the transformer to be adjusted is located according to the real-time power supply voltage, the real-time power supply active power, the real-time power supply reactive power, the equivalent resistance and equivalent reactance of the main line;

[0026] According to the real-time measurement data of the low-voltage side of the transformer to be adjusted, the real-time voltage, real-time active power and real-time reactive power of the low-voltage side of the transformer to be adjusted are obtained;

[0027] According to the current iterative transformation ratio value, the real-time voltage on the low-voltage side, the real-time active power on the low-voltage side and the real-time reactive power on the low-voltage side, respectively determine the high-voltage side voltage, the high-voltage side active power and the high-voltage side reactive power of the transformer to be adjusted under the current iterative transformation ratio value;

[0028] Determine the high-voltage side outlet point voltage and the high-voltage side outlet point power of the transformer to be adjusted according to the transformer resistance, the transformer reactance, the transformer excitation power, the equivalent susceptance of the branch line, the high-voltage side voltage of the transformer to be adjusted at the current iterative transformation ratio, the high-voltage side active power and the high-voltage side reactive power;

[0029] Determine the input power of the branch line where the transformer to be adjusted is located according to the voltage of the high-voltage side outlet point, the power of the high-voltage side outlet point, the equivalent resistance of the branch line, the equivalent reactance of the branch line and the equivalent susceptance of the branch line;

[0030] The high-voltage side voltage of the transformer to be adjusted is determined according to the transformer resistance, the transformer reactance, the equivalent resistance of the branch line, the equivalent reactance of the branch line, the input voltage, the input power and the high-voltage side outlet point power.

[0031] As a preferred solution, the step of determining the input voltage of the branch line where the transformer to be adjusted is located according to the real-time power supply voltage, the real-time power supply active power, the real-time power supply reactive power, the equivalent resistance and equivalent reactance of the main line specifically includes:

[0032] According to the real-time power supply voltage, the real-time power supply active power, the real-time power supply reactive power, the equivalent resistance and equivalent reactance of the main line, the input voltage of the branch line where the transformer to be adjusted is located is determined by the following expression:

[0033] ;

[0034] in, Indicates the input voltage of the branch line where the transformer to be adjusted is located; Indicates the real-time supply voltage; Indicates the real-time power supply active power; Indicates the real-time power supply reactive power; represents the equivalent resistance of the main line; Represents the equivalent reactance of the main line.

[0035] As a preferred solution, the high-voltage side outlet point voltage and high-voltage side outlet point power of the transformer to be adjusted are determined according to the transformer resistance, the transformer reactance, the transformer excitation power, the equivalent susceptance of the branch line, the high-voltage side voltage of the transformer to be adjusted at the current iterative transformation ratio, the high-voltage side active power and the high-voltage side reactive power, specifically including:

[0036] According to the transformer resistance, the transformer reactance, the high-voltage side voltage of the transformer to be adjusted at the current iterative transformation ratio, the high-voltage side active power and the high-voltage side reactive power, the high-voltage side outlet point voltage is determined by the following expression:

[0037] ;

[0038] According to the voltage at the high-voltage side outlet point, the transformer resistance, the transformer reactance, the transformer excitation power, the equivalent susceptance of the branch line, the high-voltage side voltage of the transformer to be adjusted at the current iterative transformation ratio, the high-voltage side active power and the high-voltage side reactive power, the power at the high-voltage side outlet point is determined by the following expression:

[0039] ;

[0040] in, Indicates the voltage of the high-voltage side outlet point; represents the power of the high-voltage side outlet point, where: Indicates the active power of the high-voltage side outlet point. Indicates the reactive power of the high-voltage side outlet point; represents the transformer resistance; represents the transformer reactance; represents the transformer excitation power; represents the equivalent susceptance of the branch line; Indicates the high-voltage side voltage of the transformer to be adjusted under the current iterative transformation ratio value; Indicates the active power on the high-voltage side of the transformer to be adjusted under the current iterative transformation ratio value; It indicates the reactive power on the high-voltage side of the transformer to be adjusted under the current iterative transformation ratio value.

[0041] As a preferred solution, the input power of the branch line where the transformer to be adjusted is located is determined according to the voltage of the high-voltage side outlet point, the power of the high-voltage side outlet point, the equivalent resistance of the branch line, the equivalent reactance of the branch line and the equivalent susceptance of the branch line, specifically including:

[0042] According to the voltage at the high-voltage side outlet point, the power at the high-voltage side outlet point, the equivalent resistance of the branch line, the equivalent reactance of the branch line and the equivalent susceptance of the branch line, the input power of the branch line where the transformer to be adjusted is located is determined by the following expression:

[0043] ;

[0044] in, represents the input power of the branch line where the transformer to be adjusted is located, where: represents the input active power of the branch line where the transformer to be adjusted is located, Indicates the input reactive power of the branch line where the transformer to be adjusted is located; represents the power of the high-voltage side outlet point, where: Indicates the active power of the high-voltage side outlet point. Indicates the reactive power of the high-voltage side outlet point; represents the equivalent resistance of the branch line; represents the equivalent reactance of the branch line; represents the equivalent susceptance of the branch line; Indicates the voltage of the high-voltage side outlet point.

[0045] As a preferred solution, the high-voltage side voltage of the transformer to be adjusted is determined according to the transformer resistance, the transformer reactance, the equivalent resistance of the branch line, the equivalent reactance of the branch line, the input voltage, the input power and the high-voltage side outlet power, specifically including:

[0046] According to the equivalent resistance of the branch line, the equivalent reactance of the branch line, the input voltage and the input power, the voltage adjustment value of the high-voltage side outlet point of the transformer to be adjusted is determined by the following expression:

[0047] ;

[0048] According to the voltage adjustment value of the high-voltage side outlet point, the power of the high-voltage side outlet point, the transformer resistance and the transformer reactance, the high-voltage side voltage of the transformer to be adjusted is determined by the following expression:

[0049] ;

[0050] in, Indicates the voltage adjustment value of the high-voltage side outlet point; Indicates the high voltage side voltage of the transformer to be adjusted; represents the transformer resistance; represents the transformer reactance; represents the equivalent resistance of the branch line; represents the equivalent reactance of the branch line; represents the input voltage; represents the input power; Indicates the active power of the high-voltage side outlet point. Indicates the reactive power at the high-voltage side outgoing point.

[0051] As a preferred solution, the preset accuracy requirement is specifically: ,in, represents the update ratio of the i-th iteration process, represents the iterative transformation ratio of the i-th iteration process, Indicates the preset tolerance value.

[0052] A second aspect of an embodiment of the present invention provides a transformer ratio acquisition system based on power flow coupling characteristics, including:

[0053] Parameter acquisition module, used for:

[0054] Determine the equivalent circuit parameters and transformer parameters corresponding to the transformer to be adjusted according to the equipment information and power grid data of the transformer to be adjusted;

[0055] High-voltage side voltage acquisition module, used for:

[0056] Determine the high-voltage side voltage of the transformer to be adjusted according to the real-time measurement data of the line where the transformer to be adjusted is located, the real-time measurement data of the low-voltage side of the transformer to be adjusted, the current iterative transformation ratio value, the equivalent circuit parameters and the transformer parameters; wherein the initial value of the current iterative transformation ratio value is a preset standard transformation ratio value;

[0057] The ratio iterative update module is used to:

[0058] Determine a current updated transformation ratio value according to the high voltage side voltage and the low voltage side real-time measurement data;

[0059] The currently updated transformation ratio value is used as the current iterative transformation ratio value, and the steps for determining the high-voltage side voltage are re-executed through the high-voltage side voltage acquisition module until the error between the currently updated transformation ratio value and the current iterative transformation ratio value meets the preset accuracy requirement, and the currently updated transformation ratio value is used as the target transformation ratio value of the transformer to be adjusted, so as to adjust the transformation ratio of the transformer to be adjusted according to the target transformation ratio value and the target distribution network voltage to be adjusted.

[0060] Compared with the prior art, the beneficial effect of the embodiments of the present invention lies in that, through the real-time measurement data of the installed metering equipment, the equipment information of the transformer and the power grid data, the transformer ratio information can be obtained quickly and accurately based on the power flow coupling characteristics, without the need to install additional ratio metering equipment or manual on-site measurement, which significantly improves the efficiency of obtaining the transformer ratio information and effectively meets the real-time requirements of the distribution network voltage regulation for the transformer ratio information. BRIEF DESCRIPTION OF THE DRAWINGS

[0061] Figure 1 is a flow chart of a method for obtaining a transformer ratio based on power flow coupling characteristics in an embodiment of the present invention;

[0062] Figure 2 It is a circuit topology structure of an embodiment of the transformer provided by the present invention;

[0063] Figure 3 yes Figure 2 Equivalent circuit diagram corresponding to the circuit topology structure in the figure;

[0064] Figure 4 It is a structural schematic diagram of a transformer ratio acquisition method based on power flow coupling characteristics in an embodiment of the present invention. DETAILED DESCRIPTION

[0065] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0066] See also Figure 1 According to a first aspect of an embodiment of the present invention, a method for obtaining a transformer ratio based on power flow coupling characteristics is provided, comprising the following steps S1 to S4:

[0067] Step S1, determining equivalent circuit parameters and transformer parameters corresponding to the transformer to be adjusted according to equipment information and power grid data of the transformer to be adjusted;

[0068] Step S2, determining the high-voltage side voltage of the transformer to be adjusted according to the real-time measurement data of the line where the transformer to be adjusted is located, the real-time measurement data of the low-voltage side of the transformer to be adjusted, the current iterative transformation ratio value, the equivalent circuit parameters and the transformer parameters; wherein the initial value of the current iterative transformation ratio value is a preset standard transformation ratio value;

[0069] Step S3, determining a current updated transformation ratio value according to the high voltage side voltage and the low voltage side real-time measurement data;

[0070] Step S4, taking the currently updated transformation ratio value as the current iterative transformation ratio value, and re-executing the step for determining the high-voltage side voltage, until the error between the currently updated transformation ratio value and the current iterative transformation ratio value meets the preset accuracy requirement, taking the currently updated transformation ratio value as the target transformation ratio value of the transformer to be adjusted, so as to adjust the transformation ratio of the transformer to be adjusted according to the target transformation ratio value and the target distribution network voltage to be adjusted.

[0071] Specifically, the power flow coupling characteristic refers to the coupling characteristics of the voltage and power between different nodes under the same line of the power system, so that based on the real-time measurement data of the metering equipment installed in the line where the transformer to be adjusted is located, the remaining unknown electrical quantities, such as the high-voltage side voltage of the transformer to be adjusted, can be obtained based on the power flow coupling characteristics, and then the target transformation ratio value of the transformer to be adjusted can be determined. In order to ensure the accuracy of the transformer transformation ratio information obtained, this embodiment first needs to determine the equivalent circuit corresponding to the transformer to be adjusted according to the equipment information of the transformer to be adjusted and the corresponding power grid data, and obtain the corresponding equivalent circuit parameters and transformer parameters. It can be understood that in the equivalent circuit, each node of the line where the transformer to be adjusted is located can be clearly defined, such as the power supply point of the main line, the connection point between the branch line and the main line where the transformer to be adjusted is located, the high-voltage side node of the transformer to be adjusted, and the low-voltage side node, and the equivalent circuit parameters define the equivalent resistance, equivalent reactance, and equivalent susceptance of the line between each node.

[0072] Furthermore, based on the installed metering equipment, real-time measurement data of the line where the transformer to be adjusted is located and real-time measurement data of the low-voltage side of the transformer to be adjusted can be obtained. It can be understood that the actual transformation ratio value of the transformer to be adjusted is the target transformation ratio value to be obtained, so this embodiment continuously iterates and adjusts from the preset standard transformation ratio value, so that the transformation ratio value obtained in each iteration continuously approaches the actual transformation ratio value, wherein the preset standard transformation ratio value is the ratio of the ideal voltages of the lines at both ends of the transformer to be adjusted, that is, under ideal conditions, the transformation ratio value of the transformer to be adjusted is the turns ratio of the primary coil to the secondary coil.

[0073] When the error between the updated transformation ratio value obtained in a certain iteration and the current iterative transformation ratio value meets the preset accuracy requirement, it indicates that the updated transformation ratio value has converged to the actual transformation ratio value of the transformer to be adjusted, and thus it is used as the final target transformation ratio value. After clarifying the target transformation ratio value of the transformer to be adjusted, the transformation ratio of the transformer to be adjusted can be accurately adjusted based on the target distribution network voltage, thereby increasing the accuracy of distribution network voltage adjustment, achieving efficient voltage adjustment when the load changes drastically, and enhancing the safety and stability of distribution network operation.

[0074] The transformer ratio acquisition method based on power flow coupling characteristics provided in the embodiment of the present invention can quickly and accurately acquire transformer ratio information based on power flow coupling characteristics through real-time measurement data of installed metering equipment, equipment information of the transformer and power grid data. No additional ratio metering equipment is required, and no manual on-site measurement is required. This significantly improves the efficiency of acquiring transformer ratio information and effectively meets the real-time requirements of distribution network voltage regulation for transformer ratio information.

[0075] As a preferred solution, determining the equivalent circuit parameters and transformer parameters corresponding to the transformer to be adjusted according to the equipment information and power grid data of the transformer to be adjusted specifically includes:

[0076] According to the equipment information of the transformer to be adjusted, the rated capacity, rated high-voltage side voltage, no-load loss, no-load current percentage, short-circuit loss and short-circuit voltage percentage of the transformer to be adjusted are obtained;

[0077] According to the rated capacity, the rated high-voltage side voltage, the no-load loss, the no-load current percentage, the short-circuit loss and the short-circuit voltage percentage, respectively determine the transformer resistance, transformer reactance and transformer excitation power, and use the transformer resistance, transformer reactance and transformer excitation power as the transformer parameters;

[0078] Determining a circuit topology structure corresponding to the transformer to be adjusted according to the power grid data;

[0079] According to the preset unit distance resistance, unit distance reactance, unit distance susceptance of the line, the length of the main line in the circuit topology structure and the length of the branch line where the transformer to be adjusted is located, the equivalent resistance, equivalent reactance and equivalent susceptance of the main line and the branch line are determined respectively, and the equivalent resistance, the equivalent reactance and the equivalent susceptance are used as the equivalent circuit parameters.

[0080] It is worth noting that if Figure 2 As shown, it is the circuit topology of the transformer under one of the embodiments, point a is the power supply point of the entire line, and electric energy is supplied from this point to the tree-shaped distribution network. Generally speaking, there is a metering device at this point to measure voltage and power; point b is the connection point between the branch line where the transformer to be adjusted is located and the main line. The power at this point includes the power input to the branch line where the transformer to be adjusted is located and the power supplied to the branch line where other subsequent transformers are located; point c is the high-voltage side of the transformer to be adjusted. Generally speaking, there is no metering device at this point; point d is the output end of the transformer to be adjusted that supplies power to its substation, that is, the low-voltage side of the transformer to be adjusted. Generally speaking, there is a metering device at this point to measure voltage and power; in addition, there are line connections between each point. Based on this circuit topology, the length of the line between each point can be clearly determined, and the equivalent resistance, equivalent reactance and equivalent susceptance of the main line and branch line can be determined by the following expressions:

[0081] ;

[0082] in, , and are the equivalent resistance, equivalent reactance and equivalent susceptance of line L in the equivalent circuit respectively; , and They represent the resistance per unit distance, reactance per unit distance and susceptance per unit distance of line L respectively; represents the length of line L. Further, in combination with the determined transformer resistance, transformer reactance and transformer excitation power, an equivalent circuit diagram of the transformer to be processed can be constructed, such as Figure 3 As shown, Figure 3 Points A, B, C and D in the figure correspond to points a, b, c and d in the above circuit topology respectively. , and They represent the equivalent resistance, equivalent reactance and equivalent susceptance of the main line between point A and point B respectively. , and They represent the equivalent resistance, equivalent reactance and equivalent susceptance of the branch line between point B and point C respectively. , and They represent transformer resistance, transformer reactance and transformer excitation power respectively. It represents the power supplied by point B to the branch lines where other subsequent transformers are located, and k represents the transformation ratio of the transformer to be adjusted.

[0083] As a preferred solution, the transformer resistance, transformer reactance and transformer excitation power are determined respectively according to the rated capacity, the rated high-voltage side voltage, the no-load loss, the no-load current percentage, the short-circuit loss and the short-circuit voltage percentage, specifically including:

[0084] According to the short-circuit loss, the rated high-voltage side voltage and the rated capacity, the transformer resistance is determined by the following expression:

[0085] ;

[0086] According to the no-load loss, the no-load current percentage and the rated capacity, the transformer excitation power is determined by the following expression:

[0087] ;

[0088] According to the short-circuit voltage percentage, the rated high-voltage side voltage and the rated capacity, the transformer reactance is determined by the following expression;

[0089] ;

[0090] in, represents the transformer resistance; represents the transformer excitation power; represents the transformer reactance; Indicates the rated capacity; Indicates the rated high voltage side voltage; represents the no-load loss; Indicates the no-load current percentage; represents the short-circuit loss; Indicates the short-circuit voltage percentage.

[0091] As a preferred solution, the high-voltage side voltage of the transformer to be adjusted is determined according to the real-time measurement data of the line where the transformer to be adjusted is located, the real-time measurement data of the low-voltage side of the transformer to be adjusted, the current iterative transformation ratio, the equivalent circuit parameters and the transformer parameters, specifically including:

[0092] According to the real-time measurement data of the line where the transformer to be adjusted is located, the real-time power supply voltage, the real-time power supply active power and the real-time power supply reactive power are obtained;

[0093] Determine the input voltage of the branch line where the transformer to be adjusted is located according to the real-time power supply voltage, the real-time power supply active power, the real-time power supply reactive power, the equivalent resistance and equivalent reactance of the main line;

[0094] According to the real-time measurement data of the low-voltage side of the transformer to be adjusted, the real-time voltage, real-time active power and real-time reactive power of the low-voltage side of the transformer to be adjusted are obtained;

[0095] According to the current iterative transformation ratio value, the real-time voltage on the low-voltage side, the real-time active power on the low-voltage side and the real-time reactive power on the low-voltage side, respectively determine the high-voltage side voltage, the high-voltage side active power and the high-voltage side reactive power of the transformer to be adjusted under the current iterative transformation ratio value;

[0096] Determine the high-voltage side outlet point voltage and the high-voltage side outlet point power of the transformer to be adjusted according to the transformer resistance, the transformer reactance, the transformer excitation power, the equivalent susceptance of the branch line, the high-voltage side voltage of the transformer to be adjusted at the current iterative transformation ratio, the high-voltage side active power and the high-voltage side reactive power;

[0097] Determine the input power of the branch line where the transformer to be adjusted is located according to the voltage of the high-voltage side outlet point, the power of the high-voltage side outlet point, the equivalent resistance of the branch line, the equivalent reactance of the branch line and the equivalent susceptance of the branch line;

[0098] The high-voltage side voltage of the transformer to be adjusted is determined according to the transformer resistance, the transformer reactance, the equivalent resistance of the branch line, the equivalent reactance of the branch line, the input voltage, the input power and the high-voltage side outlet point power.

[0099] Specifically, this embodiment returns the transformer parameters to the high-voltage side, so that the low-voltage side of the transformer to be adjusted no longer considers the loss of power and voltage, and directly calculates the high-voltage side voltage, high-voltage side active power and high-voltage side reactive power of the transformer to be adjusted under the current iterative transformation ratio according to the current iterative transformation ratio, as shown in the following expression:

[0100] ;

[0101] in, Indicates the high-voltage side voltage of the transformer to be adjusted under the current iterative transformation ratio value; Indicates the active power on the high-voltage side of the transformer to be adjusted under the current iterative transformation ratio value; Indicates the reactive power on the high-voltage side of the transformer to be adjusted under the current iterative transformation ratio value; is the current iteration ratio value. In the first iteration, it is the preset initial value, that is, the preset standard ratio value. In the subsequent iterations, it is the updated iteration value generated by the previous iteration. , and They respectively represent the real-time voltage on the low-voltage side, the real-time active power on the low-voltage side and the real-time reactive power on the low-voltage side.

[0102] Furthermore, taking into account the losses caused by transformer resistance and transformer reactance, combined with the high-voltage side voltage, high-voltage side active power and high-voltage side reactive power obtained by the above calculation, the high-voltage side outlet point voltage and high-voltage side outlet point power under the current iterative transformation ratio can be calculated.

[0103] Furthermore, taking into account the power loss in the branch line, combined with its equivalent resistance, equivalent reactance, equivalent susceptance and the high-voltage side outlet point voltage and high-voltage side outlet point power obtained by the above calculations, the input power of the branch line where the transformer to be adjusted is located can be calculated.

[0104] Furthermore, since the calculated input power of the branch line where the transformer to be adjusted is located is calculated based on the current iterative transformation ratio value, and the current iterative transformation ratio value may not be the target transformation ratio value, the input power deviates from the input power under the actual target transformation ratio value. The input voltage of the branch line where the transformer to be adjusted is calculated based on the real-time measurement data of the main line power supply point, which is not affected by the current iterative transformation ratio value. Therefore, this embodiment uses the calculated input voltage, input power and transformer parameters of the branch line to reversely calculate the high-voltage side voltage of the transformer to be adjusted. After continuous iterative calculation, the calculated high-voltage side voltage will continue to approach the actual high-voltage side voltage, so that an accurate target transformation ratio value can be obtained.

[0105] It is worth noting that based on the acquired real-time measurement data of the low-voltage side, the real-time voltage of the low-voltage side can be determined. Therefore, according to the high-voltage side voltage and the real-time measurement data of the low-voltage side, the current updated transformation ratio value is determined by the following expression:

[0106] ;

[0107] in, Represents the updated variable ratio value of the i-th iteration process; Indicates the high voltage side voltage of the transformer to be adjusted; Represents the real-time measurement data of the low-pressure side.

[0108] As a preferred solution, the step of determining the input voltage of the branch line where the transformer to be adjusted is located according to the real-time power supply voltage, the real-time power supply active power, the real-time power supply reactive power, the equivalent resistance and equivalent reactance of the main line specifically includes:

[0109] According to the real-time power supply voltage, the real-time power supply active power, the real-time power supply reactive power, the equivalent resistance and equivalent reactance of the main line, the input voltage of the branch line where the transformer to be adjusted is located is determined by the following expression:

[0110] ;

[0111] in, Indicates the input voltage of the branch line where the transformer to be adjusted is located; Indicates the real-time supply voltage; Indicates the real-time power supply active power; Indicates the real-time power supply reactive power; represents the equivalent resistance of the main line; Represents the equivalent reactance of the main line.

[0112] It is worth noting that due to the transmission loss of the line during the power transmission process, there will be a voltage drop between the two nodes at the beginning and end of the line. In the above expression, the longitudinal component of the voltage drop of the main line is used to determine The expression is:

[0113] ;

[0114] Used to determine the voltage drop cross component of the main line The expression is:

[0115] ;

[0116] Based on the real-time power supply voltage, the longitudinal component of the voltage drop in the main line and the transverse component of the voltage drop, the input voltage at the input end of the branch line where the transformer to be adjusted is located can be determined.

[0117] As a preferred solution, the high-voltage side outlet point voltage and high-voltage side outlet point power of the transformer to be adjusted are determined according to the transformer resistance, the transformer reactance, the transformer excitation power, the equivalent susceptance of the branch line, the high-voltage side voltage of the transformer to be adjusted at the current iterative transformation ratio, the high-voltage side active power and the high-voltage side reactive power, specifically including:

[0118] According to the transformer resistance, the transformer reactance, the high-voltage side voltage of the transformer to be adjusted at the current iterative transformation ratio, the high-voltage side active power and the high-voltage side reactive power, the high-voltage side outlet point voltage is determined by the following expression:

[0119] ;

[0120] According to the voltage at the high-voltage side outlet point, the transformer resistance, the transformer reactance, the transformer excitation power, the equivalent susceptance of the branch line, the high-voltage side voltage of the transformer to be adjusted at the current iterative transformation ratio, the high-voltage side active power and the high-voltage side reactive power, the power at the high-voltage side outlet point is determined by the following expression:

[0121] ;

[0122] in, Indicates the voltage of the high-voltage side outlet point; represents the power of the high-voltage side outlet point, where: Indicates the active power of the high-voltage side outlet point. Indicates the reactive power of the high-voltage side outlet point; represents the transformer resistance; represents the transformer reactance; represents the transformer excitation power; represents the equivalent susceptance of the branch line; Indicates the high-voltage side voltage of the transformer to be adjusted under the current iterative transformation ratio value; Indicates the active power on the high-voltage side of the transformer to be adjusted under the current iterative transformation ratio value; It indicates the reactive power on the high-voltage side of the transformer to be adjusted under the current iterative transformation ratio value.

[0123] It is understandable that due to the short-circuit loss and no-load loss of the transformer to be adjusted, there will be a voltage drop between the high-voltage side voltage and the high-voltage side outlet voltage. In the above expression, the longitudinal component of the voltage drop of the transformer is used to determine The expression is:

[0124] ;

[0125] Used to determine the longitudinal component of the voltage drop of the transformer The expression is:

[0126] ;

[0127] Based on the high-voltage side voltage under the current iterative transformation ratio, the voltage drop longitudinal component and the voltage drop transverse component of the transformer, the high-voltage side outlet point voltage under the current iterative transformation ratio can be determined.

[0128] Furthermore, this embodiment determines the impedance loss of the transformer to be adjusted by the following expression: :

[0129] ;

[0130] Then the admittance loss of the transformer to be adjusted is determined by the following expression: :

[0131] ;

[0132] Based on the transformer excitation power, high-voltage side active power, high-voltage side reactive power, impedance loss and admittance loss of the transformer to be adjusted, the power at the high-voltage side outlet point can be determined.

[0133] As a preferred solution, the input power of the branch line where the transformer to be adjusted is located is determined according to the voltage of the high-voltage side outlet point, the power of the high-voltage side outlet point, the equivalent resistance of the branch line, the equivalent reactance of the branch line and the equivalent susceptance of the branch line, specifically including:

[0134] According to the voltage at the high-voltage side outlet point, the power at the high-voltage side outlet point, the equivalent resistance of the branch line, the equivalent reactance of the branch line and the equivalent susceptance of the branch line, the input power of the branch line where the transformer to be adjusted is located is determined by the following expression:

[0135] ;

[0136] in, represents the input power of the branch line where the transformer to be adjusted is located, where: represents the input active power of the branch line where the transformer to be adjusted is located, Indicates the input reactive power of the branch line where the transformer to be adjusted is located; represents the power of the high-voltage side outlet point, where: Indicates the active power of the high-voltage side outlet point. Indicates the reactive power of the high-voltage side outlet point; represents the equivalent resistance of the branch line; represents the equivalent reactance of the branch line; represents the equivalent susceptance of the branch line; Indicates the voltage of the high-voltage side outlet point.

[0137] It is understandable that there will be impedance loss and admittance loss during line transmission, which will lead to power loss between the two ends of the line. Specifically, this embodiment determines the impedance loss of the branch line through the following expression: :

[0138] ;

[0139] Then the admittance loss of the branch line is determined by the following expression: :

[0140] ;

[0141] Based on the power at the high-voltage side outlet point, the impedance loss and admittance loss of the branch line, the input power of the branch line can be determined.

[0142] As a preferred solution, the high-voltage side voltage of the transformer to be adjusted is determined according to the transformer resistance, the transformer reactance, the equivalent resistance of the branch line, the equivalent reactance of the branch line, the input voltage, the input power and the high-voltage side outlet power, specifically including:

[0143] According to the equivalent resistance of the branch line, the equivalent reactance of the branch line, the input voltage and the input power, the voltage adjustment value of the high-voltage side outlet point of the transformer to be adjusted is determined by the following expression:

[0144] ;

[0145] According to the voltage adjustment value of the high-voltage side outlet point, the power of the high-voltage side outlet point, the transformer resistance and the transformer reactance, the high-voltage side voltage of the transformer to be adjusted is determined by the following expression:

[0146] ;

[0147] in, Indicates the voltage adjustment value of the high-voltage side outlet point; Indicates the high voltage side voltage of the transformer to be adjusted; represents the transformer resistance; represents the transformer reactance; represents the equivalent resistance of the branch line; represents the equivalent reactance of the branch line; represents the input voltage; represents the input power; Indicates the active power of the high-voltage side outlet point. Indicates the reactive power at the high-voltage side outgoing point.

[0148] It can be understood that the voltage at the high-voltage side outlet point is the voltage at the connection point between the branch line where the transformer to be adjusted is located and the high-voltage side outlet of the transformer to be adjusted. There will be transmission loss in the branch line, so there will be a voltage drop between the two nodes at the beginning and end of the line. In the above expression, the longitudinal component of the voltage drop of the branch line is used to determine The expression is:

[0149] ;

[0150] Used to determine the voltage drop cross component of the branch line The expression is:

[0151] ;

[0152] Based on the input voltage, the longitudinal component of the voltage drop and the transverse component of the voltage drop of the branch line, the voltage adjustment value of the high-voltage side outlet point of the transformer to be adjusted can be recalculated. After continuous iterative adjustment, the voltage adjustment value of the high-voltage side outlet point will continue to approach the actual high-voltage side outlet point voltage.

[0153] Furthermore, based on the voltage adjustment value of the high-voltage side outlet point, the voltage drop longitudinal component and the voltage drop transverse component of the transformer can be re-determined, and finally the high-voltage side voltage of the transformer to be adjusted can be calculated. As the voltage adjustment value of the high-voltage side outlet point approaches the actual high-voltage side outlet point voltage through continuous iterative adjustment, the calculated high-voltage side voltage can also continuously approach the actual high-voltage side voltage, thereby finally obtaining an accurate target transformation ratio value.

[0154] As a preferred solution, the preset accuracy requirement is specifically: ,in, represents the update ratio of the i-th iteration process, represents the iterative transformation ratio of the i-th iteration process, Indicates the preset tolerance value.

[0155] It can be understood that the smaller the difference between the updated transformation ratio value and the iterative transformation ratio value in the i-th iteration process, the closer the updated transformation ratio value is to the actual transformation ratio value, that is, the target transformation ratio value. Therefore, the allowable error value is adjusted according to the accuracy requirement of the transformer transformation ratio value. This embodiment is not specifically limited here. When the allowable error value is large, the number of iterations is small, which can meet the use scenarios with low requirements for the transformer transformation ratio accuracy and improve the efficiency of obtaining the transformer transformation ratio; when the allowable error value is small, it can better meet the use scenarios with high requirements for the transformer transformation ratio accuracy.

[0156] See also Figure 4 A second aspect of an embodiment of the present invention provides a transformer ratio acquisition system based on power flow coupling characteristics, comprising:

[0157] The parameter acquisition module 101 is used to:

[0158] Determine the equivalent circuit parameters and transformer parameters corresponding to the transformer to be adjusted according to the equipment information and power grid data of the transformer to be adjusted;

[0159] The high-voltage side voltage acquisition module 102 is used to:

[0160] Determine the high-voltage side voltage of the transformer to be adjusted according to the real-time measurement data of the line where the transformer to be adjusted is located, the real-time measurement data of the low-voltage side of the transformer to be adjusted, the current iterative transformation ratio value, the equivalent circuit parameters and the transformer parameters; wherein the initial value of the current iterative transformation ratio value is a preset standard transformation ratio value;

[0161] The transformation ratio iterative updating module 103 is used for:

[0162] Determine a current updated transformation ratio value according to the high voltage side voltage and the low voltage side real-time measurement data;

[0163] The currently updated transformation ratio value is used as the current iterative transformation ratio value, and the steps for determining the high-voltage side voltage are re-executed through the high-voltage side voltage acquisition module 102 until the error between the currently updated transformation ratio value and the current iterative transformation ratio value meets the preset accuracy requirement, and the currently updated transformation ratio value is used as the target transformation ratio value of the transformer to be adjusted, so as to adjust the transformation ratio of the transformer to be adjusted according to the target transformation ratio value and the target distribution network voltage to be adjusted.

[0164] As a preferred solution, the parameter acquisition module 101 is used to determine the equivalent circuit parameters and transformer parameters corresponding to the transformer to be adjusted according to the equipment information and power grid data of the transformer to be adjusted, specifically including:

[0165] According to the equipment information of the transformer to be adjusted, the rated capacity, rated high-voltage side voltage, no-load loss, no-load current percentage, short-circuit loss and short-circuit voltage percentage of the transformer to be adjusted are obtained;

[0166] According to the rated capacity, the rated high-voltage side voltage, the no-load loss, the no-load current percentage, the short-circuit loss and the short-circuit voltage percentage, respectively determine the transformer resistance, transformer reactance and transformer excitation power, and use the transformer resistance, transformer reactance and transformer excitation power as the transformer parameters;

[0167] Determining a circuit topology structure corresponding to the transformer to be adjusted according to the power grid data;

[0168] According to the preset unit distance resistance, unit distance reactance, unit distance susceptance of the line, the length of the main line in the circuit topology structure and the length of the branch line where the transformer to be adjusted is located, the equivalent resistance, equivalent reactance and equivalent susceptance of the main line and the branch line are determined respectively, and the equivalent resistance, the equivalent reactance and the equivalent susceptance are used as the equivalent circuit parameters.

[0169] As a preferred solution, the parameter acquisition module 101 is used to determine the transformer resistance, transformer reactance and transformer excitation power according to the rated capacity, the rated high-voltage side voltage, the no-load loss, the no-load current percentage, the short-circuit loss and the short-circuit voltage percentage, respectively, specifically including:

[0170] According to the short-circuit loss, the rated high-voltage side voltage and the rated capacity, the transformer resistance is determined by the following expression:

[0171] ;

[0172] According to the no-load loss, the no-load current percentage and the rated capacity, the transformer excitation power is determined by the following expression:

[0173] ;

[0174] According to the short-circuit voltage percentage, the rated high-voltage side voltage and the rated capacity, the transformer reactance is determined by the following expression;

[0175] ;

[0176] in, represents the transformer resistance; represents the transformer excitation power; represents the transformer reactance; Indicates the rated capacity; Indicates the rated high voltage side voltage; represents the no-load loss; Indicates the no-load current percentage; represents the short-circuit loss; Indicates the short-circuit voltage percentage.

[0177] As a preferred solution, the high-voltage side voltage acquisition module 102 is used to determine the high-voltage side voltage of the transformer to be adjusted according to the real-time measurement data of the line where the transformer to be adjusted is located, the real-time measurement data of the low-voltage side of the transformer to be adjusted, the current iterative transformation ratio, the equivalent circuit parameters and the transformer parameters, specifically including:

[0178] According to the real-time measurement data of the line where the transformer to be adjusted is located, the real-time power supply voltage, the real-time power supply active power and the real-time power supply reactive power are obtained;

[0179] Determine the input voltage of the branch line where the transformer to be adjusted is located according to the real-time power supply voltage, the real-time power supply active power, the real-time power supply reactive power, the equivalent resistance and equivalent reactance of the main line;

[0180] According to the real-time measurement data of the low-voltage side of the transformer to be adjusted, the real-time voltage, real-time active power and real-time reactive power of the low-voltage side of the transformer to be adjusted are obtained;

[0181] According to the current iterative transformation ratio value, the real-time voltage on the low-voltage side, the real-time active power on the low-voltage side and the real-time reactive power on the low-voltage side, respectively determine the high-voltage side voltage, the high-voltage side active power and the high-voltage side reactive power of the transformer to be adjusted under the current iterative transformation ratio value;

[0182] Determine the high-voltage side outlet point voltage and the high-voltage side outlet point power of the transformer to be adjusted according to the transformer resistance, the transformer reactance, the transformer excitation power, the equivalent susceptance of the branch line, the high-voltage side voltage of the transformer to be adjusted at the current iterative transformation ratio, the high-voltage side active power and the high-voltage side reactive power;

[0183] Determine the input power of the branch line where the transformer to be adjusted is located according to the voltage of the high-voltage side outlet point, the power of the high-voltage side outlet point, the equivalent resistance of the branch line, the equivalent reactance of the branch line and the equivalent susceptance of the branch line;

[0184] The high-voltage side voltage of the transformer to be adjusted is determined according to the transformer resistance, the transformer reactance, the equivalent resistance of the branch line, the equivalent reactance of the branch line, the input voltage, the input power and the high-voltage side outlet point power.

[0185] As a preferred solution, the high-voltage side voltage acquisition module 102 is used to determine the input voltage of the branch line where the transformer to be adjusted is located according to the real-time power supply voltage, the real-time power supply active power, the real-time power supply reactive power, the equivalent resistance and equivalent reactance of the main line, specifically including:

[0186] According to the real-time power supply voltage, the real-time power supply active power, the real-time power supply reactive power, the equivalent resistance and equivalent reactance of the main line, the input voltage of the branch line where the transformer to be adjusted is located is determined by the following expression:

[0187] ;

[0188] in, Indicates the input voltage of the branch line where the transformer to be adjusted is located; Indicates the real-time supply voltage; Indicates the real-time power supply active power; Indicates the real-time power supply reactive power; represents the equivalent resistance of the main line; Represents the equivalent reactance of the main line.

[0189] As a preferred solution, the high-voltage side voltage acquisition module 102 is used to determine the high-voltage side outlet point voltage and high-voltage side outlet point power of the transformer to be adjusted according to the transformer resistance, the transformer reactance, the transformer excitation power, the equivalent susceptance of the branch line, the high-voltage side voltage of the transformer to be adjusted at the current iterative transformation ratio, the high-voltage side active power and the high-voltage side reactive power, specifically including:

[0190] According to the transformer resistance, the transformer reactance, the high-voltage side voltage of the transformer to be adjusted at the current iterative transformation ratio, the high-voltage side active power and the high-voltage side reactive power, the high-voltage side outlet point voltage is determined by the following expression:

[0191] ;

[0192] According to the voltage at the high-voltage side outlet point, the transformer resistance, the transformer reactance, the transformer excitation power, the equivalent susceptance of the branch line, the high-voltage side voltage of the transformer to be adjusted at the current iterative transformation ratio, the high-voltage side active power and the high-voltage side reactive power, the power at the high-voltage side outlet point is determined by the following expression:

[0193] ;

[0194] in, Indicates the voltage of the high-voltage side outlet point; represents the power of the high-voltage side outlet point, where: Indicates the active power of the high-voltage side outlet point. Indicates the reactive power of the high-voltage side outlet point; represents the transformer resistance; represents the transformer reactance; represents the transformer excitation power; represents the equivalent susceptance of the branch line; Indicates the high-voltage side voltage of the transformer to be adjusted under the current iterative transformation ratio value; Indicates the active power on the high-voltage side of the transformer to be adjusted under the current iterative transformation ratio value; It indicates the reactive power on the high-voltage side of the transformer to be adjusted under the current iterative transformation ratio value.

[0195] As a preferred solution, the high-voltage side voltage acquisition module 102 is used to determine the input power of the branch line where the transformer to be adjusted is located according to the high-voltage side outlet point voltage, the high-voltage side outlet point power, the equivalent resistance of the branch line, the equivalent reactance of the branch line and the equivalent susceptance of the branch line, specifically including:

[0196] According to the voltage at the high-voltage side outlet point, the power at the high-voltage side outlet point, the equivalent resistance of the branch line, the equivalent reactance of the branch line and the equivalent susceptance of the branch line, the input power of the branch line where the transformer to be adjusted is located is determined by the following expression:

[0197] ;

[0198] in, represents the input power of the branch line where the transformer to be adjusted is located, where: represents the input active power of the branch line where the transformer to be adjusted is located, Indicates the input reactive power of the branch line where the transformer to be adjusted is located; represents the power of the high-voltage side outlet point, where: Indicates the active power of the high-voltage side outlet point. Indicates the reactive power of the high-voltage side outlet point; represents the equivalent resistance of the branch line; represents the equivalent reactance of the branch line; represents the equivalent susceptance of the branch line; Indicates the voltage of the high-voltage side outlet point.

[0199] As a preferred solution, the high-voltage side voltage acquisition module 102 is used to determine the high-voltage side voltage of the transformer to be adjusted according to the transformer resistance, the transformer reactance, the equivalent resistance of the branch line, the equivalent reactance of the branch line, the input voltage, the input power and the high-voltage side outlet point power, specifically including:

[0200] According to the equivalent resistance of the branch line, the equivalent reactance of the branch line, the input voltage and the input power, the voltage adjustment value of the high-voltage side outlet point of the transformer to be adjusted is determined by the following expression:

[0201] ;

[0202] According to the voltage adjustment value of the high-voltage side outlet point, the power of the high-voltage side outlet point, the transformer resistance and the transformer reactance, the high-voltage side voltage of the transformer to be adjusted is determined by the following expression:

[0203] ;

[0204] in, Indicates the voltage adjustment value of the high-voltage side outlet point; Indicates the high voltage side voltage of the transformer to be adjusted; represents the transformer resistance; represents the transformer reactance; represents the equivalent resistance of the branch line; represents the equivalent reactance of the branch line; represents the input voltage; represents the input power; Indicates the active power of the high-voltage side outlet point. Indicates the reactive power at the high-voltage side outgoing point.

[0205] As a preferred solution, the preset accuracy requirement is specifically: ,in, represents the update ratio of the i-th iteration process, represents the iterative transformation ratio of the i-th iteration process, Indicates the preset tolerance value.

[0206] The transformer ratio acquisition system based on power flow coupling characteristics provided in the embodiment of the present invention can quickly and accurately acquire transformer ratio information based on power flow coupling characteristics through real-time measurement data of installed metering equipment, equipment information of the transformer and power grid data. No additional ratio metering equipment is required, and no manual on-site measurement is required. This significantly improves the efficiency of acquiring transformer ratio information and effectively meets the real-time requirements of distribution network voltage regulation for transformer ratio information.

[0207] The above is a preferred embodiment of the present invention. It should be pointed out that a person skilled in the art can make several improvements and modifications without departing from the principle of the present invention. These improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A method for obtaining transformer ratio based on power flow coupling characteristics, characterized in that: include: Determine the equivalent circuit parameters and transformer parameters corresponding to the transformer to be adjusted according to the equipment information and power grid data of the transformer to be adjusted; Determine the high-voltage side voltage of the transformer to be adjusted according to the real-time measurement data of the line where the transformer to be adjusted is located, the real-time measurement data of the low-voltage side of the transformer to be adjusted, the current iterative transformation ratio value, the equivalent circuit parameters and the transformer parameters; wherein the initial value of the current iterative transformation ratio value is a preset standard transformation ratio value; Determine a current updated transformation ratio value according to the high voltage side voltage and the low voltage side real-time measurement data; The current updated transformation ratio value is used as the current iterative transformation ratio value, and the step of determining the high-voltage side voltage is re-executed until the error between the current updated transformation ratio value and the current iterative transformation ratio value meets the preset accuracy requirement, and the current updated transformation ratio value is used as the target transformation ratio value of the transformer to be adjusted, so as to adjust the transformation ratio of the transformer to be adjusted according to the target transformation ratio value and the target distribution network voltage to be adjusted; The preset accuracy requirement is specifically: ,in, represents the update ratio of the i-th iteration process, represents the iterative transformation ratio of the i-th iteration process, Indicates the preset tolerance value.

2. The method for obtaining transformer ratio based on power flow coupling characteristics according to claim 1, characterized in that: Determining the equivalent circuit parameters and transformer parameters corresponding to the transformer to be adjusted according to the equipment information and power grid data of the transformer to be adjusted specifically includes: According to the equipment information of the transformer to be adjusted, the rated capacity, rated high-voltage side voltage, no-load loss, no-load current percentage, short-circuit loss and short-circuit voltage percentage of the transformer to be adjusted are obtained; According to the rated capacity, the rated high-voltage side voltage, the no-load loss, the no-load current percentage, the short-circuit loss and the short-circuit voltage percentage, respectively determine the transformer resistance, transformer reactance and transformer excitation power, and use the transformer resistance, transformer reactance and transformer excitation power as the transformer parameters; Determining a circuit topology structure corresponding to the transformer to be adjusted according to the power grid data; According to the preset unit distance resistance, unit distance reactance, unit distance susceptance of the line, the length of the main line in the circuit topology structure and the length of the branch line where the transformer to be adjusted is located, the equivalent resistance, equivalent reactance and equivalent susceptance of the main line and the branch line are determined respectively, and the equivalent resistance, the equivalent reactance and the equivalent susceptance are used as the equivalent circuit parameters.

3. The method for obtaining transformer ratio based on power flow coupling characteristics according to claim 2, characterized in that: The step of determining the transformer resistance, transformer reactance and transformer excitation power according to the rated capacity, the rated high-voltage side voltage, the no-load loss, the no-load current percentage, the short-circuit loss and the short-circuit voltage percentage respectively specifically includes: According to the short-circuit loss, the rated high-voltage side voltage and the rated capacity, the transformer resistance is determined by the following expression: ； According to the no-load loss, the no-load current percentage and the rated capacity, the transformer excitation power is determined by the following expression: ； According to the short-circuit voltage percentage, the rated high-voltage side voltage and the rated capacity, the transformer reactance is determined by the following expression; ； in, represents the transformer resistance; represents the transformer excitation power; represents the transformer reactance; Indicates the rated capacity; Indicates the rated high voltage side voltage; represents the no-load loss; Indicates the no-load current percentage; represents the short-circuit loss; Indicates the short-circuit voltage percentage.

4. The method for obtaining transformer ratio based on power flow coupling characteristics according to claim 2, characterized in that: Determining the high-voltage side voltage of the transformer to be adjusted according to the real-time measurement data of the line where the transformer to be adjusted is located, the real-time measurement data of the low-voltage side of the transformer to be adjusted, the current iterative transformation ratio, the equivalent circuit parameters and the transformer parameters specifically includes: According to the real-time measurement data of the line where the transformer to be adjusted is located, the real-time power supply voltage, the real-time power supply active power and the real-time power supply reactive power are obtained; Determine the input voltage of the branch line where the transformer to be adjusted is located according to the real-time power supply voltage, the real-time power supply active power, the real-time power supply reactive power, the equivalent resistance and equivalent reactance of the main line; According to the real-time measurement data of the low-voltage side of the transformer to be adjusted, the real-time voltage, real-time active power and real-time reactive power of the low-voltage side of the transformer to be adjusted are obtained; According to the current iterative transformation ratio value, the real-time voltage on the low-voltage side, the real-time active power on the low-voltage side and the real-time reactive power on the low-voltage side, respectively determine the high-voltage side voltage, the high-voltage side active power and the high-voltage side reactive power of the transformer to be adjusted under the current iterative transformation ratio value; Determine the high-voltage side outlet point voltage and the high-voltage side outlet point power of the transformer to be adjusted according to the transformer resistance, the transformer reactance, the transformer excitation power, the equivalent susceptance of the branch line, the high-voltage side voltage of the transformer to be adjusted at the current iterative transformation ratio, the high-voltage side active power and the high-voltage side reactive power; Determine the input power of the branch line where the transformer to be adjusted is located according to the voltage of the high-voltage side outlet point, the power of the high-voltage side outlet point, the equivalent resistance of the branch line, the equivalent reactance of the branch line and the equivalent susceptance of the branch line; The high-voltage side voltage of the transformer to be adjusted is determined according to the transformer resistance, the transformer reactance, the equivalent resistance of the branch line, the equivalent reactance of the branch line, the input voltage, the input power and the high-voltage side outlet point power.

5. The method for obtaining transformer ratio based on power flow coupling characteristics according to claim 4, characterized in that: Determining the input voltage of the branch line where the transformer to be adjusted is located according to the real-time power supply voltage, the real-time power supply active power, the real-time power supply reactive power, the equivalent resistance and equivalent reactance of the main line specifically includes: According to the real-time power supply voltage, the real-time power supply active power, the real-time power supply reactive power, the equivalent resistance and equivalent reactance of the main line, the input voltage of the branch line where the transformer to be adjusted is located is determined by the following expression: ； in, Indicates the input voltage of the branch line where the transformer to be adjusted is located; Indicates the real-time supply voltage; Indicates the real-time power supply active power; Indicates the real-time power supply reactive power; represents the equivalent resistance of the main line; Represents the equivalent reactance of the main line.

6. The method for obtaining transformer ratio based on power flow coupling characteristics according to claim 4, characterized in that: Determining the high-voltage side outlet point voltage and the high-voltage side outlet point power of the transformer to be adjusted according to the transformer resistance, the transformer reactance, the transformer excitation power, the equivalent susceptance of the branch line, the high-voltage side voltage of the transformer to be adjusted at the current iterative transformation ratio, the high-voltage side active power and the high-voltage side reactive power, specifically includes: According to the transformer resistance, the transformer reactance, the high-voltage side voltage of the transformer to be adjusted at the current iterative transformation ratio, the high-voltage side active power and the high-voltage side reactive power, the high-voltage side outlet point voltage is determined by the following expression: ； According to the voltage at the high-voltage side outlet point, the transformer resistance, the transformer reactance, the transformer excitation power, the equivalent susceptance of the branch line, the high-voltage side voltage of the transformer to be adjusted at the current iterative transformation ratio, the high-voltage side active power and the high-voltage side reactive power, the power at the high-voltage side outlet point is determined by the following expression: ； in, Indicates the voltage of the high-voltage side outlet point; represents the power of the high-voltage side outlet point, where: Indicates the active power of the high-voltage side outlet point. Indicates the reactive power of the high-voltage side outlet point; represents the transformer resistance; represents the transformer reactance; represents the transformer excitation power; represents the equivalent susceptance of the branch line; Indicates the high-voltage side voltage of the transformer to be adjusted under the current iterative transformation ratio value; Indicates the active power on the high-voltage side of the transformer to be adjusted under the current iterative transformation ratio value; It indicates the reactive power on the high-voltage side of the transformer to be adjusted under the current iterative transformation ratio value.

7. The method for obtaining transformer ratio based on power flow coupling characteristics according to claim 4, characterized in that: Determining the input power of the branch line where the transformer to be adjusted is located according to the voltage of the high-voltage side outlet point, the power of the high-voltage side outlet point, the equivalent resistance of the branch line, the equivalent reactance of the branch line and the equivalent susceptance of the branch line specifically includes: According to the voltage at the high-voltage side outlet point, the power at the high-voltage side outlet point, the equivalent resistance of the branch line, the equivalent reactance of the branch line and the equivalent susceptance of the branch line, the input power of the branch line where the transformer to be adjusted is located is determined by the following expression: ； in, represents the input power of the branch line where the transformer to be adjusted is located, where: represents the input active power of the branch line where the transformer to be adjusted is located, Indicates the input reactive power of the branch line where the transformer to be adjusted is located; represents the power of the high-voltage side outlet point, where: Indicates the active power of the high-voltage side outlet point. Indicates the reactive power of the high-voltage side outlet point; represents the equivalent resistance of the branch line; represents the equivalent reactance of the branch line; represents the equivalent susceptance of the branch line; Indicates the voltage of the high-voltage side outlet point.

8. The method for obtaining transformer ratio based on power flow coupling characteristics according to claim 4, characterized in that: Determining the high-voltage side voltage of the transformer to be adjusted according to the transformer resistance, the transformer reactance, the equivalent resistance of the branch line, the equivalent reactance of the branch line, the input voltage, the input power and the high-voltage side outlet power specifically includes: According to the equivalent resistance of the branch line, the equivalent reactance of the branch line, the input voltage and the input power, the voltage adjustment value of the high-voltage side outlet point of the transformer to be adjusted is determined by the following expression: ； According to the voltage adjustment value of the high-voltage side outlet point, the power of the high-voltage side outlet point, the transformer resistance and the transformer reactance, the high-voltage side voltage of the transformer to be adjusted is determined by the following expression: ； in, Indicates the voltage adjustment value of the high-voltage side outlet point; Indicates the high voltage side voltage of the transformer to be adjusted; represents the transformer resistance; represents the transformer reactance; represents the equivalent resistance of the branch line; represents the equivalent reactance of the branch line; represents the input voltage; represents the input power; Indicates the active power of the high-voltage side outlet point. Indicates the reactive power at the high-voltage side outgoing point.

9. A transformer ratio acquisition system based on power flow coupling characteristics, characterized in that: include: Parameter acquisition module, used for: Determine the equivalent circuit parameters and transformer parameters corresponding to the transformer to be adjusted according to the equipment information and power grid data of the transformer to be adjusted; High-voltage side voltage acquisition module, used for: Determine the high-voltage side voltage of the transformer to be adjusted according to the real-time measurement data of the line where the transformer to be adjusted is located, the real-time measurement data of the low-voltage side of the transformer to be adjusted, the current iterative transformation ratio value, the equivalent circuit parameters and the transformer parameters; wherein the initial value of the current iterative transformation ratio value is a preset standard transformation ratio value; The ratio iterative update module is used to: Determine a current updated transformation ratio value according to the high voltage side voltage and the low voltage side real-time measurement data; The currently updated transformation ratio value is used as the current iterative transformation ratio value, and the step of determining the high-voltage side voltage is re-executed by the high-voltage side voltage acquisition module until the error between the currently updated transformation ratio value and the current iterative transformation ratio value meets the preset accuracy requirement, and the currently updated transformation ratio value is used as the target transformation ratio value of the transformer to be adjusted, so as to adjust the transformation ratio of the transformer to be adjusted according to the target transformation ratio value and the target distribution network voltage to be adjusted; The preset accuracy requirement is specifically: ,in, represents the update ratio of the i-th iteration process, represents the iterative transformation ratio of the i-th iteration process, Indicates the preset tolerance value.

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