CN113722657A - Transformer reactance optimization method and device and transformer - Google Patents

Transformer reactance optimization method and device and transformer Download PDF

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CN113722657A
CN113722657A CN202110925523.7A CN202110925523A CN113722657A CN 113722657 A CN113722657 A CN 113722657A CN 202110925523 A CN202110925523 A CN 202110925523A CN 113722657 A CN113722657 A CN 113722657A
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CN113722657B (en
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许恺
陈骥群
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State Grid Corp of China SGCC
Baoding Power Supply Co of State Grid Hebei Electric Power Co Ltd
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Baoding Power Supply Co of State Grid Hebei Electric Power Co Ltd
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Abstract

The invention relates to the field of power, in particular to a method and a device for optimizing reactance of a transformer and the transformer. The specific optimization method of the transformer reactance comprises the following steps: acquiring the current load of the transformer; acquiring a weight coefficient of a current load; acquiring an optimal reactance value of the transformer under the current load according to the current load and the weight coefficient; acquiring a reactance deviation value according to the optimal reactance value and the actual reactance value of the transformer; compensating the actual reactance value of the transformer according to the reactance deviation value to generate an optimized reactance value of the transformer, wherein the optimized reactance value of the transformer is equal to the optimal reactance value of the transformer; the device comprises a load coefficient acquisition module; a weight obtaining module; an optimal reactance value acquisition module; a reactance difference value acquisition module; and a compensation module. The method and the device solve the technical problems that the reactance of the transformer cannot be optimized in real time and the economical efficiency and the reliability of the transformer cannot be considered in the related technology.

Description

Transformer reactance optimization method and device and transformer
Technical Field
The invention relates to the field of power, in particular to a method and a device for optimizing reactance of a transformer and the transformer.
Background
The power system planning and designing technology mainly relates to the planning and designing of primary and secondary electric parts, communication parts and the like, and respectively corresponds to technical subjects such as parameter selection and equipment arrangement of electric equipment in power plants and transformer substation stations, design of relay protection devices and dispatching automation systems, planning and designing of communication networks and the like. In the primary electrical design process of a transformer substation, selection of reactance parameters of a main transformer is an important problem.
Reasonable transformer reactance parameters need to ensure the short-circuit current level of a medium-low voltage bus in a transformer substation, and higher short-circuit current limits the arrangement of a power grid operation mode and causes difficulty in type selection of related equipment. In order to limit the short-circuit current of the power grid, the reactance of a transformer is increased under a constant voltage system, namely, the transformer with larger short-circuit voltage is selected, and the higher short-circuit voltage value can increase the reactive loss of the transformer, cause the voltage fluctuation of the medium-low voltage bus to exceed the standard, is not beneficial to the economic operation of the power grid, and also does not accord with the development concept of low carbon and energy conservation in the current society.
Disclosure of Invention
In view of the above, the invention provides a method and a device for optimizing a transformer reactance, and a transformer, and solves the technical problems that the transformer reactance cannot be optimized in real time and the economic efficiency and the reliable operation of the transformer cannot be considered in the prior art.
For the purpose of making the objects, technical means and advantages of the present invention more apparent, the present invention will be described in further detail with reference to the accompanying drawings.
According to an aspect of the present invention, an embodiment of the present invention provides a method for optimizing a reactance of a transformer, including: acquiring the current load of the transformer; acquiring a weight coefficient of the current load; acquiring the optimal reactance value of the transformer under the current load according to the current load and the weight coefficient; acquiring a reactance deviation value according to the optimal reactance value and the actual reactance value of the transformer; and compensating the actual reactance value of the transformer according to the reactance deviation value to generate an optimized reactance value of the transformer, wherein the optimized reactance value of the transformer is equal to the optimal reactance value of the transformer.
In an embodiment of the present invention, obtaining the optimal reactance value of the transformer under the current load according to the current load coefficient and the weight coefficient includes: acquiring the percentage of the short-circuit voltage of the transformer according to the weight coefficient of the current load coefficient; and obtaining the optimal reactance value of the transformer under the current load according to the short-circuit voltage percentage.
In an embodiment of the present invention, the current load includes three-phase short-circuit current and reactive loss of the transformer, the weight coefficient includes a first weight coefficient of the three-phase short-circuit current and a second weight coefficient of the reactive loss of the transformer, and a sum of the first weight coefficient and the second weight coefficient is 1; obtaining the short-circuit voltage percentage of the transformer according to the weight coefficient of the current load, wherein the obtaining comprises the following steps: constructing an optimization function of the transformer short-circuit voltage percentage according to the three-phase short-circuit current, the first weight coefficient, the transformer reactive loss and the second weight coefficient; and acquiring the optimal short-circuit voltage percentage of the transformer under the current load according to the optimization function of the short-circuit voltage percentage of the transformer.
In an embodiment of the present invention, obtaining the optimal short-circuit voltage percentage of the transformer under the current load according to the optimization function of the short-circuit voltage percentage of the transformer includes: and deriving an optimization function of the transformer short-circuit voltage percentage to obtain the optimal short-circuit voltage percentage of the transformer under the current load.
In an embodiment of the present invention, constructing an optimization function of the percentage of the short-circuit voltage of the transformer according to the three-phase short-circuit current, the first weight coefficient, the reactive loss of the transformer, and the second weight coefficient includes: constructing an initial optimization function of the transformer short-circuit voltage percentage according to the three-phase short-circuit current, the first weight coefficient, the transformer reactive loss and the second weight coefficient; obtaining a formula for expressing the relation between the three-phase short-circuit current and the transformer short-circuit voltage percentage according to the rated capacity and the rated voltage of the transformer; obtaining a formula for expressing the relation between the reactive loss of the transformer and the short-circuit voltage percentage of the transformer according to the rated capacity of the transformer; and calculating the initial optimization function according to a formula for expressing the relation between the three-phase short-circuit current and the transformer short-circuit voltage percentage and a formula for expressing the relation between the transformer reactive loss and the transformer short-circuit voltage percentage to generate the optimization function of the transformer short-circuit voltage percentage.
In an embodiment of the present invention, calculating the initial optimization function according to a formula representing a relationship between the three-phase short-circuit current and the transformer short-circuit voltage percentage and a formula representing a relationship between the transformer reactive loss and the transformer short-circuit voltage percentage to generate the optimization function of the transformer short-circuit voltage percentage includes: acquiring rated capacity, rated voltage and short-circuit voltage percentage of a transformer; calculating the rated voltage, the rated capacity and the short-circuit voltage percentage of the transformer according to a formula (I) to generate a reactance value of the transformer;
Figure BDA0003209010160000021
wherein, in the formula (one), XTIs the reactance value of the transformer, UNFor rated voltage of transformer, SNRated capacity of transformer, UK% is short circuit voltage percentage;
calculating the reactance value of the transformer and the voltage of the voltage source according to a formula (II) to generate three-phase short-circuit current;
Figure BDA0003209010160000031
wherein, in the formula (II), E is the voltage of the voltage source, IKIs three-phase short-circuit current;
substituting the formula (one) into the formula (two), calculating the formula (two), and generating the formula (three) for expressing the relation between the three-phase short-circuit current and the short-circuit voltage percentage.
Figure BDA0003209010160000032
In an embodiment of the present invention, the corrected value of the rated voltage of the transformer is a preset multiple of the rated voltage of the transformer, and the preset multiple of the rated voltage of the transformer is 1.0 to 1.1.
In an embodiment of the present invention, obtaining a formula representing a relationship between the reactive loss of the transformer and the short-circuit voltage percentage of the transformer according to the rated capacity of the transformer includes: acquiring a transformer current value and a transformer reactance value; converting the secondary current of the transformer to a current value of a primary side of the transformer and a reactance value of the transformer according to a formula (IV) to calculate so as to generate reactive loss of the transformer;
ΔQ＝I2'2XTformula (IV)
Wherein, in the formula (IV), I2' converting the secondary current of the transformer to the current value of the primary side of the transformer, and delta Q is the reactive loss of the transformer;
calculating the actual load power of the transformer and the voltage value converted from the secondary voltage of the transformer to the primary side of the transformer according to a formula (V) to generate a current value converted from the secondary current of the transformer to the primary side of the transformer;
Figure BDA0003209010160000033
wherein, formula (V), UbIs the voltage value of the secondary voltage of the transformer converted to the primary side of the transformer, SLThe actual load power of the transformer;
substituting the formula (one) into the formula (four) to generate a formula (six) for expressing the relation between the reactive loss and the short-circuit voltage percentage of the transformer;
Figure BDA0003209010160000041
calculating the rated capacity of the transformer and the current load of the transformer according to a formula (VII) to obtain the actual load power of the transformer;
SL＝βSNformula (seven)
In the formula (VII), beta is the current load coefficient of the transformer;
according to Ub’≈UNAnd (seven), calculating the formula (six), and generating a formula (eight) for expressing the relation between the reactive loss and the short-circuit voltage percentage of the transformer.
Figure BDA0003209010160000042
According to a second aspect of the present invention, another embodiment of the present invention provides a reactance optimization apparatus for a transformer, the reactance optimization apparatus being configured to apply the above reactance optimization method for a transformer, the reactance optimization apparatus including: the load coefficient acquisition module is used for acquiring the current load coefficient of the transformer; the weight obtaining module is used for obtaining a weight coefficient of the current load coefficient; the optimal reactance value acquisition module is used for acquiring an optimal reactance value; the reactance difference value acquisition module is used for acquiring a reactance difference value; and the compensation module is used for adjusting the actual reactance value to the optimal reactance value according to the reactance deviation value.
According to a third aspect of the present invention, another embodiment of the present invention provides a transformer, which includes the reactance optimization device described in the above embodiment.
The method for optimizing the reactance of the transformer provided by the embodiment of the invention is based on the real-time load of the transformer, reduces the three-phase short-circuit current of the transformer, improves the efficiency of the transformer as a constraint condition, determines a weight coefficient according to the load property, optimizes the optimal value of the reactance of the transformer under the current load, compares the optimal value with the actual reactance value of the transformer, inputs the reactance deviation value into a control module, generates a control pulse to a compensation module by the control module, and adjusts inductance and capacitance parameters to ensure that the integral reactance value of a transformer unit is the optimal reactance value.
Drawings
Fig. 1 is a schematic flowchart illustrating a method for optimizing a reactance of a transformer according to an embodiment of the present invention;
fig. 2 is a schematic diagram illustrating an architecture of an apparatus for optimizing a transformer reactance according to another embodiment of the present invention;
fig. 3 is a schematic diagram of a simulation circuit of a method for optimizing a reactance of a transformer according to another embodiment of the present invention;
fig. 4 is a schematic diagram illustrating a simulation test result of a method for optimizing a transformer reactance according to an embodiment of the present invention.
Detailed Description
In the description of the present invention, "a plurality" means at least two, e.g., two, three, etc., unless specifically limited otherwise. All directional indicators in the embodiments of the present invention (such as upper, lower, left, right, front, rear, top, bottom … …) are only used to explain the relative position, motion, etc. of the components in a particular position (as shown in the drawings), and if the particular position is changed, the directional indicator is changed accordingly. Furthermore, the terms "include" and "have," as well as any variations thereof, are intended to cover non-exclusive inclusions. For example, a process, method, system, article, or apparatus that comprises a list of steps or elements is not limited to only those steps or elements listed, but may alternatively include other steps or elements not listed, or inherent to such process, method, article, or apparatus.
Furthermore, reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the invention. The appearances of the phrase in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. It is explicitly and implicitly understood by one skilled in the art that the embodiments described herein can be combined with other embodiments.
The applicant further analyzes the reasons of the technical problems that the reactance of the transformer cannot be optimized in real time and the economical efficiency and the reliable operation of the transformer cannot be considered in the related technology, and the following results are obtained:
reasonable transformer reactance parameters need to ensure the short-circuit current level of a medium-low voltage bus in a transformer substation, and higher short-circuit current limits the arrangement of a power grid operation mode and causes difficulty in type selection of related equipment. In order to limit the short-circuit current of the power grid, the reactance of a transformer is increased under a constant voltage system, namely, the transformer with larger short-circuit voltage is selected, and the higher short-circuit voltage value can increase the reactive loss of the transformer, cause the voltage fluctuation of the medium-low voltage bus to exceed the standard, is not beneficial to the economic operation of the power grid, and also does not accord with the development concept of low carbon and energy conservation in the current society. Therefore, in order to solve the problems, the invention provides an optimal control method of the reactance of the transformer on the basis of comprehensively considering the reliability and the economy of the operation of the power grid.
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Fig. 1 is a schematic flowchart illustrating a method for optimizing a transformer reactance according to an embodiment of the present application, where as shown in fig. 1, the method for optimizing a transformer reactance includes the following steps:
step S1: collecting the current load beta of the transformer;
step S2: determining a weight coefficient alpha according to the current load;
step S3: obtaining the optimal reactance value of the transformer under the current load according to the current load beta and the weight coefficient alpha;
step S4: acquiring a reactance deviation value according to the optimal reactance value and the actual reactance value of the transformer;
step S5: and compensating the actual reactance value of the transformer according to the reactance deviation value to generate an optimized reactance value of the transformer.
Wherein the optimized reactance value of the transformer is equal to the optimized reactance value of the transformer.
According to the method and device for optimizing the reactance of the transformer, the current load of the transformer is taken as a basis, the weight coefficient is determined according to the load property, the optimal value of the reactance under the current load of the transformer is preferably selected, the reactance deviation value is compared with the actual reactance value of the transformer, a control pulse is generated according to the reactance deviation value and sent to the compensation module, inductance and capacitance parameters are adjusted, the transformer unit is enabled to operate at the optimal reactance value, various loads of the transformer are effectively coordinated, the reliability and the economical efficiency of a system are enabled to be in a relatively balanced state, and further the comprehensive performance of the system is enabled to be optimal.
Specifically, in an embodiment of the present application, step S3 includes the following steps:
step S31: acquiring the short-circuit voltage percentage of the transformer according to the weight coefficient of the current load;
step S32: and obtaining the optimal reactance value of the transformer under the current load according to the short-circuit voltage percentage.
The short-circuit voltage percentage of the transformer plays a decisive role in the magnitude of short-circuit current generated when the transformer is suddenly short-circuited on the secondary side, so that the optimal reactance value of the transformer under the current load can be obtained more reliably and practically according to the short-circuit voltage percentage.
Specifically, in an embodiment of the present application, the current load in step S31 includes three-phase short-circuit current and reactive loss of the transformer, and therefore, the weight coefficient includes a first weight coefficient α of the three-phase short-circuit current1And a second weight coefficient alpha of the transformer reactive loss2Wherein α is1+α2＝1。
Step S31 includes the following steps:
step S311: according to the three-phase short-circuit current and the first weight coefficient alpha1Transformer reactive loss and second weight coefficient alpha2Constructing an optimization function of the short-circuit voltage percentage of the transformer;
step S312: and obtaining the optimal short-circuit voltage percentage of the transformer under the current load according to the optimization function of the short-circuit voltage percentage of the transformer.
The percentage of the short-circuit voltage of the transformer is increased, the three-phase short-circuit current of the transformer can be effectively inhibited, the power supply reliability is improved, meanwhile, the reactive loss of the transformer is also increased, and the economic operation of a power grid is not facilitated. Therefore, the method for optimizing the short-circuit voltage percentage of the transformer is provided on the basis of comprehensively considering the operation reliability and the economical efficiency of the transformer, the three-phase short-circuit current and the reactive loss of the transformer are taken as constraint conditions, and a first weight coefficient alpha is respectively set1And a second weight coefficient alpha2And constructing an optimization function of the system to obtain the optimal short-circuit voltage percentage of the transformer, and further obtaining the optimal reactance value of the transformer according to the optimal short-circuit voltage percentage.
Specifically, in an embodiment of the present application, in step S312, a derivative is obtained from an optimization function of the transformer short-circuit voltage percentage, so as to obtain an optimal short-circuit voltage percentage of the transformer under the current load. And obtaining the optimal reactance value of the transformer under the current load according to the optimal short-circuit voltage percentage of the transformer under the current load.
When the three-phase short-circuit current and the reactive loss of the transformer are the minimum values, the reliability and the economy of the system power supply can reach the best, and obviously, the optimization function takes the minimum value at the moment. Therefore, the corresponding short-circuit voltage percentage at the minimum point of the optimization function is the optimized optimal short-circuit voltage percentage, and the reactance value under the optimal short-circuit voltage percentage is the optimal reactance value of the transformer.
Specifically, in an embodiment of the present application, the process of constructing the optimization function in step S312 includes the following steps:
step S3121: according to the three-phase short-circuit current and the first weight coefficient alpha1Transformer reactive loss and second weight coefficient alpha2Constructing an initial optimization function of the short-circuit voltage percentage of the transformer；
Step S3122: obtaining a formula for expressing the relation between the three-phase short-circuit current and the percentage of the transformer short-circuit voltage according to the rated capacity and the rated voltage of the transformer;
step S3123: obtaining a formula for expressing the relation between the reactive loss of the transformer and the short-circuit voltage percentage of the transformer according to the rated capacity of the transformer;
step S3124: and calculating the initial optimization function according to a formula for expressing the relation between the three-phase short-circuit current and the transformer short-circuit voltage percentage and a formula for expressing the relation between the transformer reactive loss and the transformer short-circuit voltage percentage to generate the optimization function of the transformer short-circuit voltage percentage.
Specifically, in an embodiment of the present application, in step S3124, an initial optimization function is calculated according to a formula representing a relationship between three-phase short-circuit current and transformer short-circuit voltage percentage, and the specific steps of generating the optimization function of transformer short-circuit voltage percentage are as follows:
acquiring rated capacity, rated voltage and short-circuit voltage percentage of a transformer;
calculating the rated voltage, the rated capacity and the short-circuit voltage percentage of the transformer according to a formula (I) to generate a reactance value of the transformer, wherein the formula (I) is as follows:
Figure BDA0003209010160000071
wherein, in the formula (one), XTIs the reactance value of the transformer, UNFor rated voltage of transformer, SNRated capacity of transformer, UK% is short circuit voltage percentage;
calculating the reactance value of the transformer and the voltage of a voltage source according to a formula (II) to generate three-phase short-circuit current, wherein the formula (II) is shown in the specification;
Figure BDA0003209010160000081
wherein, in the formula (II), E is the voltage of the voltage source, IKIs three-phase short-circuit current;
substituting the formula (one) into the formula (two), calculating the formula (two), and generating the formula (three) for expressing the relation between the three-phase short-circuit current and the short-circuit voltage percentage.
Figure BDA0003209010160000082
According to the formula (III), when the power supply voltage is in a certain grade, in order to reduce the three-phase short-circuit current, the short-circuit voltage percentage of the transformer can be increased or the rated capacity of the transformer can be reduced, and the reduction of the rated capacity of the transformer is not beneficial to the use of the transformer in the urban high-load density area, so that the increase of the short-circuit voltage percentage is an effective way for inhibiting the three-phase short-circuit current.
Specifically, in an embodiment of the present application, the corrected value of the rated voltage of the transformer is a preset multiple of the rated voltage of the transformer, and the preset multiple of the rated voltage of the transformer is 1.05, that is, E is 1.05UNAnd calculating to obtain:
Figure BDA0003209010160000083
specifically, in an embodiment of the present application, in step S3124, an initial optimization function is calculated according to a formula representing a relationship between a reactive loss of the transformer and a short-circuit voltage percentage of the transformer, and specific steps of generating the optimization function of the short-circuit voltage percentage of the transformer include:
acquiring a transformer current value and a transformer reactance value;
and (3) calculating the current value of the secondary current of the transformer converted to the primary side of the transformer and the reactance value of the transformer according to a formula (IV) to generate the reactive loss of the transformer, wherein the formula (IV) is as follows:
ΔQ＝I2'2XTformula (IV)
Wherein, the formula (IV)) In (I)2The' is the current value converted from the secondary current of the transformer to the primary side of the transformer, and the delta Q is the reactive loss of the transformer;
calculating the actual load power of the transformer and the voltage value converted from the secondary voltage of the transformer to the primary side of the transformer according to a formula (V) to generate a current value converted from the secondary current of the transformer to the primary side of the transformer, wherein the formula (V) is as follows:
Figure BDA0003209010160000084
wherein, in the formula (V), UbIs the voltage value of the secondary voltage of the transformer converted to the primary side of the transformer, SLThe actual load power of the transformer;
substituting the formula (I) and the formula (V) into the formula (IV) to generate a formula (VI) for expressing the relation between the reactive loss of the transformer and the short-circuit voltage percentage;
Figure BDA0003209010160000091
calculating the rated capacity of the transformer and the current load of the transformer according to a formula (VII) to obtain the actual load power of the transformer;
SL＝βSNformula (seven)
In the formula (VII), beta is the current load coefficient of the transformer;
according to Ub’≈UNFormula (VI), calculating formula (VI), and generating formula (eight) for expressing the relation between the reactive loss and the short-circuit voltage percentage of the transformer;
Figure BDA0003209010160000092
substituting the formula (three) and the formula (eight) into the initial function to generate an optimization function of the short-circuit voltage percentage of the transformer, wherein the optimization function of the short-circuit voltage percentage of the transformer is as follows:
Figure BDA0003209010160000093
and (3) carrying out derivation on the optimization function, wherein the derivation formula is as follows:
Figure BDA0003209010160000094
the optimal value of the percentage of the short-circuit voltage corresponding to the minimum value of the function is as follows:
Figure BDA0003209010160000095
wherein, UK% is the optimum short circuit voltage percentage.
Substituting the optimal short-circuit voltage percentage into equation (one) to generate equation (nine) for calculating the optimal reactance value of the transformer, wherein equation (nine) is:
Figure BDA0003209010160000096
wherein, in the formula (nine), XTIs the optimal reactance value of the transformer. The optimal reactance value of the transformer under the current load can be obtained through the formula (nine), the load coefficient of the transformer, the first weight coefficient, the second weight coefficient, the rated capacity of the transformer and the rated voltage of the transformer, so that the transformer can adjust the current reactance value to the optimal reactance value, and meanwhile, the reliability and the economical efficiency of the transformer in the operation process are improved.
As a second aspect of the present application, the present application provides a reactance optimization apparatus for a transformer, for applying the optimization method of the reactance of the transformer as shown in fig. 1. As shown in fig. 2, the reactance optimization device of the transformer comprises the following modules:
the load coefficient acquisition module is used for acquiring the current load of the transformer;
the weight acquisition module is used for acquiring a weight coefficient of the current load;
the optimal reactance value acquisition module is used for acquiring an optimal reactance value;
the reactance difference value acquisition module is used for acquiring a reactance difference value;
and the compensation module is used for adjusting the actual reactance value to the optimal reactance value according to the reactance deviation value.
The embodiment of the application provides a reactance optimizing apparatus of transformer, current load through gathering the vary voltage obtains the weight coefficient to obtain optimum reactance value through current load and weight coefficient, compare optimum reactance value and actual reactance value, obtain the reactance deviation value, carry out the deviation compensation to actual reactance value through the compensation module at last, adjust actual reactance value to optimum reactance value, and then make the operating system of transformer be in the higher state of reliability and economic nature.
As a third aspect of the present application, the present application provides a transformer for applying an optimization device of transformer reactance as shown in fig. 2.
Specifically, in an embodiment of the present application, referring to fig. 3, a simulation circuit model diagram is shown in which the reactance optimization method of the transformer in the present application is applied, and simulation parameters thereof are shown in the following table.
TABLE 1 simulation parameters of simulation circuits
Parameter(s) Numerical value
Rated voltage S of transformerN/MVA 120
Rated voltage U of high-voltage side of transformerN/kV 220
Rated voltage U of low-voltage side of transformerb/kV 20
Load factor beta 0.5
Weight coefficient alpha1 0.4
Weight coefficient alpha2 0.6
Substituting the simulation parameters into the formula in the embodiment to calculate the optimal short-circuit voltage percentage U of the current transformerk％0The total performance of the transformer is optimal when the total performance is 8.57%.
Selecting transformer short circuit voltage percentage Uk％1When the reactance deviation value is 5%, the reactance deviation value Δ X at that time is calculatedT1When the measured value is 14.40 Ω, Δ X is measuredT1And inputting the compensation module, adjusting the capacitance and inductance parameters of the transformer by the compensation module, compensating the actual reactance of the transformer, and acquiring and comparing the comprehensive performance of the transformer before and after compensation, wherein the comparison result is shown in table 2.
Table 2 comparison table of comprehensive properties of transformer in example 1
Figure BDA0003209010160000111
As can be seen from table 2, after the reactance optimization method of the transformer in the present application is applied, the actual short-circuit voltage percentage is adjusted to the optimal short-circuit voltage percentage, and the actual reactance value is also adjusted to the optimal reactance value of the transformer, which indicates that the reactance value can be effectively adjusted by the reactance optimization method according to the current load of the transformer, so that the operating system of the transformer is in a state with high reliability and high economic efficiency.
Specifically, in an embodiment of the present application, the short-circuit voltage percentage U of the transformer is selectedk％2The reactance deviation value Δ X at this time was calculated as 10%T2-5.76 Ω, will Δ XT2And inputting the compensation module, adjusting the capacitance and inductance parameters of the transformer by the compensation module, compensating the actual reactance of the transformer, and acquiring and comparing the comprehensive performance of the transformer before and after compensation, wherein the comparison result is shown in table 3.
Table 3 comprehensive properties comparison table of transformer in example 2
Figure BDA0003209010160000112
FIG. 4 shows a transformer in Uk％0、Uk％1、Uk％2Three-phase short circuit test simulation results under three different short circuit voltage percentages, when t is 0.3s, the transformer generates three-phase short circuit, and U is known from the three-phase short circuit test simulation resultsk％1When the current is 5%, the three-phase short-circuit current of the transformer is the maximum, and the operation reliability of the power grid is the worst; at Uk％2When the current is 10%, the three-phase short-circuit current of the transformer is minimum, and the operation reliability of the power grid is optimal; at Uk％0When the ratio is 8.57%, compare UkWhen the percentage is 10%, the three-phase short-circuit current is slightly reduced.
As can be seen from the comparative analysis, the result is shown in Uk％0Optimize function value f (U) when 8.57%k%) is the minimum value, the selection of the short-circuit voltage percentage of the transformer can meet the requirements of users on the reliability and the economy of the power grid, the reactance of the transformer is optimal, and the comprehensive performance of the system is optimal.
The invention is not to be considered as limited to the specific embodiments shown and described, but is to be understood to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the appended claims.

Claims (10)

1. A method for optimizing a reactance of a transformer, comprising:
acquiring the current load of the transformer;
acquiring a weight coefficient of the current load;
acquiring the optimal reactance value of the transformer under the current load according to the current load and the weight coefficient;
acquiring a reactance deviation value according to the optimal reactance value and the actual reactance value of the transformer;
and compensating the actual reactance value of the transformer according to the reactance deviation value to generate an optimized reactance value of the transformer, wherein the optimized reactance value of the transformer is equal to the optimal reactance value of the transformer.
2. The method for optimizing the reactance of the transformer according to claim 1, wherein obtaining the optimal reactance value of the transformer currently loaded according to the current load coefficient and the weight coefficient comprises:
acquiring the percentage of the short-circuit voltage of the transformer according to the weight coefficient of the current load;
and obtaining the optimal reactance value of the transformer under the current load according to the short-circuit voltage percentage of the transformer.
3. The method of optimizing the reactance of a transformer according to claim 2, wherein the current load comprises a three-phase short-circuit current and a reactive loss of the transformer, the weight coefficients comprise a first weight coefficient of the three-phase short-circuit current and a second weight coefficient of the reactive loss of the transformer, and the sum of the first weight coefficient and the second weight coefficient is 1;
obtaining the short-circuit voltage percentage of the transformer according to the weight coefficient of the current load, wherein the obtaining comprises the following steps:
constructing an optimization function of the transformer short-circuit voltage percentage according to the three-phase short-circuit current, the first weight coefficient, the transformer reactive loss and the second weight coefficient;
and acquiring the optimal short-circuit voltage percentage of the transformer under the current load according to the optimization function of the short-circuit voltage percentage of the transformer.
4. The method for optimizing the reactance of a transformer according to claim 3, wherein obtaining the optimal short-circuit voltage percentage of the transformer at the current load according to the optimization function of the short-circuit voltage percentage of the transformer comprises:
and deriving an optimization function of the transformer short-circuit voltage percentage to obtain the optimal short-circuit voltage percentage of the transformer under the current load.
5. The method of optimizing transformer reactance of claim 3, wherein constructing an optimization function of the transformer short-circuit voltage percentage based on the three-phase short-circuit current, the first weighting factor, the transformer reactive loss, and the second weighting factor comprises:
constructing an initial optimization function of the transformer short-circuit voltage percentage according to the three-phase short-circuit current, the first weight coefficient, the transformer reactive loss and the second weight coefficient;
obtaining a formula for expressing the relation between the three-phase short-circuit current and the transformer short-circuit voltage percentage according to the rated capacity and the rated voltage of the transformer;
obtaining a formula for expressing the relation between the reactive loss of the transformer and the short-circuit voltage percentage of the transformer according to the rated capacity of the transformer;
and calculating the initial optimization function according to a formula for expressing the relation between the three-phase short-circuit current and the transformer short-circuit voltage percentage and a formula for expressing the relation between the transformer reactive loss and the transformer short-circuit voltage percentage to generate the optimization function of the transformer short-circuit voltage percentage.
6. The method of optimizing transformer reactance of claim 5, wherein calculating the initial optimization function according to a formula representing the relationship between the three-phase short-circuit current and the transformer short-circuit voltage percentage and a formula representing the relationship between the transformer reactive loss and the transformer short-circuit voltage percentage generates the optimization function of the transformer short-circuit voltage percentage, comprising:
acquiring rated capacity, rated voltage and short-circuit voltage percentage of a transformer;
calculating the rated voltage, the rated capacity and the short-circuit voltage percentage of the transformer according to a formula (I) to generate a reactance value of the transformer;
Figure FDA0003209010150000021
wherein, in the formula (one), XTIs the reactance value of the transformer, UNFor rated voltage of transformer, SNRated capacity of transformer, UK% is short circuit voltage percentage;
calculating the reactance value of the transformer and the voltage of the voltage source according to a formula (II) to generate three-phase short-circuit current;
Figure FDA0003209010150000022
wherein, in the formula (II), E is the voltage of the voltage source, IKIs three-phase short-circuit current;
substituting the formula (one) into the formula (two), calculating the formula (two), and generating the formula (three) for expressing the relation between the three-phase short-circuit current and the short-circuit voltage percentage.
Figure FDA0003209010150000023
7. The method of claim 6, wherein the modified value of the rated voltage of the transformer is a preset multiple of the rated voltage of the transformer, and the preset multiple of the rated voltage of the transformer is 1.0-1.1.
8. The method for optimizing the reactance of a transformer according to claim 5, wherein obtaining a formula representing the relationship between the reactive loss of the transformer and the percentage of the short-circuit voltage of the transformer according to the rated capacity of the transformer comprises:
acquiring a transformer current value and a transformer reactance value;
converting the secondary current of the transformer to a current value of a primary side of the transformer and a reactance value of the transformer according to a formula (IV) to calculate so as to generate reactive loss of the transformer;
ΔQ＝I2'2XTformula (IV)
Wherein, in the formula (IV), I2' converting the secondary current of the transformer to the current value of the primary side of the transformer, and delta Q is the reactive loss of the transformer;
calculating the actual load power of the transformer and the voltage value converted from the secondary voltage of the transformer to the primary side of the transformer according to a formula (V) to generate a current value converted from the secondary current of the transformer to the primary side of the transformer;
Figure FDA0003209010150000031
wherein, formula (V), UbIs the voltage value of the secondary voltage of the transformer converted to the primary side of the transformer, SLThe actual load power of the transformer;
substituting the formula (one) into the formula (four) to generate a formula (six) for expressing the relation between the reactive loss and the short-circuit voltage percentage of the transformer;
Figure FDA0003209010150000032
calculating the rated capacity of the transformer and the current load of the transformer according to a formula (VII) to obtain the actual load power of the transformer;
SL＝βSNformula (seven)
In the formula (VII), beta is the current load coefficient of the transformer;
according to Ub’≈UNAnd (seven), calculating the formula (six), and generating a formula (eight) for expressing the relation between the reactive loss and the short-circuit voltage percentage of the transformer.
Figure FDA0003209010150000033
9. A reactance optimization device for a transformer, characterized in that the reactance optimization device is used for applying the method for optimizing the reactance of the transformer according to any one of claims 1 to 8, and the reactance optimization device comprises:
the load coefficient acquisition module is used for acquiring the current load coefficient of the transformer;
the weight obtaining module is used for obtaining a weight coefficient of the current load coefficient;
the optimal reactance value acquisition module is used for acquiring an optimal reactance value;
the reactance difference value acquisition module is used for acquiring a reactance difference value;
and the compensation module is used for adjusting the actual reactance value to the optimal reactance value according to the reactance deviation value.
10. A transformer, characterized by comprising the reactance optimization device of claim 9.
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