1. A magnetic ring power frequency saturation characteristic simulation method is characterized by comprising the following steps:

s1, converting the U-I curve of the magnetic ring into a psi-I curve reflecting the magnetic flux psi of the magnetic ring and the instantaneous current I;

s2, fitting a curve of the magnetic flux psi and the instantaneous current i according to the psi-i obtained in the step S1;

s3, replacing the magnetic flux ψ fitted in step S2 with ψ ═ udt, to obtain the relationship between the instantaneous value of voltage and the instantaneous value of current;

s4, using the first term in the relation between the instantaneous voltage value and the instantaneous current value obtained in the step S3 to represent the linear impedance, and taking the high-order power term as the nonlinear impedance characteristic;

and S5, simulating the saturation characteristic of the magnetic ring by adopting the voltage-controlled current source, and using the high-order power term coefficient of the step S4 as the control coefficient of the voltage-controlled current source to realize the simulation of the power frequency saturation characteristic of the single experimental magnetic ring.

2. The method of claim 1, wherein in step S2, the fitted instantaneous current i is:

wherein, a_2k-1K is 1, 2, …, n.

3. The method of claim 1, wherein in step S3, the voltage transient and the current transient are related as follows:

wherein, a_2k-1And k is 1, 2, … and n, and u is the voltage on the test magnetic ring.

4. The method according to claim 1, wherein in step S4, the linear part and the saturation characteristic part are specifically:

wherein i_LFor linear impedance characteristics, i_nLFor nonlinear impedance characteristics, a₁Coefficient of the first term obtained for fitting, u is measureVoltage on the test magnet ring, a_2k-1To fit the resulting high power term coefficients, k is 2.

5. The method as claimed in claim 1, wherein in step S5, the voltage-controlled current source simulates the saturation characteristic of the magnetic loop, and the linear impedance and the voltage-controlled current source are connected in parallel to form an equivalent circuit of the magnetic loop.

6. The method as claimed in claim 1, wherein after the size and number of the magnetic rings to be simulated are changed, the control coefficient of the voltage-controlled current source is corrected to realize the simulation of the magnetic rings with different sizes and numbers.

7. The method of claim 6, wherein modifying the coefficients of the voltage controlled current source is specifically:

wherein k is_LThe linear impedance ratio of the magnetic ring to be simulated to the experimental magnetic ring is disclosed.

8. The method as claimed in claim 6 wherein the ratio k of the linear impedance of the magnetic loop to be simulated to the linear impedance of the experimental magnetic loop_LComprises the following steps:

wherein A 'is the sectional area of the needed simulation magnetic ring, l' is the average circumference, A is the sectional area of the magnetic ring, and l is the average circumference.

Background

Simulation is one of important research means of an electric power system, the magnetic ring is widely applied to suppression of Very Fast Transient Overvoltage (VFTO) in a GIS at present, but a simulation model for the magnetic ring mainly simulates impedance frequency variation characteristics of the magnetic ring by parallel connection of a resistor and an inductor, and the saturation characteristic of the magnetic ring under power frequency is not ignored.

Disclosure of Invention

The technical problem to be solved by the invention is to provide a method for simulating the power frequency saturation characteristic of a magnetic ring, aiming at the defects in the prior art, so that the accurate simulation of the magnetic ring is realized, and theoretical support is provided for the accurate simulation of the magnetic ring.

The invention adopts the following technical scheme:

a magnetic ring power frequency saturation characteristic simulation method comprises the following steps:

s1, converting the U-I curve of the magnetic ring into a psi-I curve reflecting the magnetic flux psi of the magnetic ring and the instantaneous current I;

s2, fitting a curve of the magnetic flux psi and the instantaneous current i according to the psi-i obtained in the step S1;

s3, replacing the magnetic flux ψ fitted in step S2 with ψ ═ udt, to obtain the relationship between the instantaneous value of voltage and the instantaneous value of current;

s4, using the first term in the relation between the instantaneous voltage value and the instantaneous current value obtained in the step S3 to represent the linear impedance, and taking the high-order power term as the nonlinear impedance characteristic;

and S5, simulating the saturation characteristic of the magnetic ring by adopting the voltage-controlled current source, and using the high-order power term coefficient of the step S4 as the control coefficient of the voltage-controlled current source to realize the simulation of the power frequency saturation characteristic of the single experimental magnetic ring.

Specifically, in step S2, the fitted instantaneous current i is:

wherein, a_2k-1K is 1, 2, …, n.

Specifically, in step S3, the relationship between the instantaneous voltage value and the instantaneous current value is as follows:

wherein, a_2k-1And k is 1, 2, … and n, and u is the voltage on the test magnetic ring.

Specifically, in step S4, the linear part and the saturation characteristic part are specifically:

wherein i_LFor linear impedance characteristics, i_nLFor nonlinear impedance characteristics, a₁Coefficient of the first term obtained by fitting, u is voltage on the test magnet ring, a_2k-1To fit the resulting high power term coefficients, k is 2.

Specifically, in step S5, in the voltage-controlled current source simulating the saturation characteristic of the magnetic loop, the linear impedance and the voltage-controlled current source are connected in parallel to form the equivalent circuit of the magnetic loop.

Specifically, after the size and the number of the magnetic rings to be simulated are changed, the control coefficient of the voltage-controlled current source is corrected, and simulation of the magnetic rings with different sizes and numbers is realized.

Further, the modifying the coefficient of the voltage-controlled current source specifically includes:

wherein k is_LThe linear impedance ratio of the magnetic ring to be simulated to the experimental magnetic ring is disclosed.

Furthermore, the linear impedance ratio k of the magnetic ring to be simulated to the experimental magnetic ring_LComprises the following steps:

wherein A 'is the sectional area of the needed simulation magnetic ring, l' is the average circumference, A is the sectional area of the magnetic ring, and l is the average circumference.

Compared with the prior art, the invention has at least the following beneficial effects:

the invention relates to a magnetic ring power frequency saturation characteristic simulation method, which comprises the steps of converting a U-I curve of a magnetic ring into a psi-I curve reflecting magnetic flux psi and instantaneous current I of the magnetic ring; fitting the magnetic flux psi and the instantaneous current i according to psi-i curves; replacing the fitted magnetic flux psi with psi ═ udt to obtain the relation between instantaneous voltage value and instantaneous current value; then, expressing linear impedance by using a first term in the relation between the instantaneous voltage value and the instantaneous current value, and taking a high-order power term as a nonlinear impedance characteristic; the simulation method has the advantages that the voltage-controlled current source is adopted to simulate the saturation characteristic of the magnetic ring, the high-order power term coefficient is used as the control coefficient of the voltage-controlled current source, and the simulation of the power frequency saturation characteristic of a single experimental magnetic ring is realized.

Further, the U-I curve is an effective value curve, which cannot reflect the electromagnetic exchange process of the magnetic ring, and therefore needs to be converted into a ψ -I curve using an instantaneous value.

Further, since the magnetic linkage ψ is not easily measured but has a relationship ψ ═ udt with voltage and the instantaneous value of voltage is easily measured, it is necessary to replace with ψ ═ udt.

Furthermore, after the linear part and the saturation characteristic part are separated, a coefficient of the saturation characteristic, namely a high-order power coefficient, can be directly used as a control coefficient of the voltage-controlled current source.

Furthermore, equivalent simulation reflecting the power frequency saturation characteristics of the magnetic ring can be realized by simulating parallel connection of the linear and saturation characteristic equivalent circuits.

Furthermore, simulation of the magnetic rings with different sizes and numbers can be realized by simulating the equivalent circuit coefficients of the magnetic rings with different sizes and numbers, re-experiment and re-modeling after the sizes and numbers of the magnetic rings are changed are avoided, and therefore the applicability of the method is enhanced.

Further, obtain the magnetic ring linearity of the magnetic ringLinear impedance ratio k of impedance to experimental magnetic ring_LAnd then the magnetic ring model coefficients under different sizes and numbers can be corrected.

In conclusion, the invention can realize the model simulation of the power frequency saturation characteristic of the magnetic ring through the voltage-controlled current source, thereby more accurately reflecting the characteristics of the magnetic ring under the power frequency.

The technical solution of the present invention is further described in detail by the accompanying drawings and embodiments.

Drawings

FIG. 1 is a U-I curve test circuit diagram;

FIG. 2 is an equivalent circuit diagram of the magnetic ring;

FIG. 3 is a U-I diagram of a magnetic ring;

FIG. 4 is a psi-i graph of a magnetic ring;

FIG. 5 is a test circuit diagram;

FIG. 6 is a comparison of U-I curves, wherein (a) is the U-I curve and (b) is the relative error;

FIG. 7 is a comparison graph of U-I curves of magnetic ring strings, wherein (a) is the U-I curve and (b) is the relative error.

Detailed Description

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 some, not all, embodiments of the present invention. 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.

It will be understood that the terms "comprises" and/or "comprising," when used in this specification and the appended claims, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

It is also to be understood that the terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used in the specification of the present invention and the appended claims, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.

It should be further understood that the term "and/or" as used in this specification and the appended claims refers to and includes any and all possible combinations of one or more of the associated listed items.

Various structural schematics according to the disclosed embodiments of the invention are shown in the drawings. The figures are not drawn to scale, wherein certain details are exaggerated and possibly omitted for clarity of presentation. The shapes of various regions, layers and their relative sizes and positional relationships shown in the drawings are merely exemplary, and deviations may occur in practice due to manufacturing tolerances or technical limitations, and a person skilled in the art may additionally design regions/layers having different shapes, sizes, relative positions, according to actual needs.

The invention discloses a magnetic ring power frequency saturation characteristic simulation method, which comprises the following steps of:

s1, measuring to obtain a U-I curve of the magnetic ring, and converting the U-I curve into a psi-I curve reflecting magnetic flux psi of the magnetic ring and instantaneous current I by adopting a piecewise linearization method;

referring to FIG. 1, the U-I curve U of the magnetic ring is measured_sThe magnetic ring is an adjustable voltage source, R is a current limiting resistor, I is current flowing through the magnetic ring, and U is voltage drop at two ends of the magnetic ring.

S2, fitting a curve of the magnetic flux psi and the instantaneous current i according to the psi-i obtained in the step S1;

the fitted magnetic flux ψ and instantaneous current i are as follows:

wherein, a_2k-1K is 1, 2, …, n.

S3, replacing the fitted magnetic flux ψ in step S2 with ψ ═ udt, to obtain the relationship between the instantaneous voltage value and the instantaneous current value;

the voltage transient and the current transient are related as follows:

wherein u is the voltage on the test magnet ring.

S4, using the first term in the relation between the instantaneous voltage value and the instantaneous current value obtained in the step S3 to represent the linear part, and representing the high-order power term as the saturation characteristic, namely the nonlinear impedance characteristic;

wherein i_LFor linear impedance characteristics, i_nLFor nonlinear impedance characteristics, a₁Coefficient of the first term obtained by fitting, u is voltage on the test magnet ring, a_2k-1To fit the resulting high power term coefficients, k is 2.

S5, simulating the saturation characteristic of the magnetic ring by adopting a voltage-controlled current source, and taking the high-order power term coefficient of the step S4 as the control coefficient of the voltage-controlled current source to realize the simulation of the power frequency saturation characteristic of the single experimental magnetic ring;

referring to fig. 2, the equivalent circuit of the magnetic ring is a parallel connection of a linear impedance and a voltage-controlled current source.

And S6, when the size and the number of the magnetic rings needing simulation are changed, the coefficients of the voltage-controlled current source are corrected.

The coefficient correction method of the voltage-controlled current source comprises the following steps:

wherein k is_LIn order to compare the linear impedance of the magnetic ring to be simulated with the linear impedance of the experimental magnetic ring, the method specifically comprises the following steps:

wherein A 'is the sectional area of the needed simulation magnetic ring, l' is the average circumference, A is the sectional area of the magnetic ring, and l is the average circumference.

In another embodiment of the present invention, a magnetic ring power frequency saturation characteristic simulation system is provided, which can be used to implement the magnetic ring power frequency saturation characteristic simulation method described above, and specifically, the magnetic ring power frequency saturation characteristic simulation system includes a conversion module, a fitting module, a replacement module, an impedance module, and a module simulation module.

The conversion module converts the U-I curve of the magnetic ring into a psi-I curve reflecting the magnetic flux psi of the magnetic ring and the instantaneous current I;

the fitting module is used for fitting the magnetic flux psi and the instantaneous current i according to the psi-i curve obtained by the conversion module;

replacing the fitted magnetic flux psi in the fitting module by psi ═ udt to obtain the relation between the instantaneous voltage value and the instantaneous current value;

the impedance module is used for representing linear impedance by using a first term in the relation between the voltage instantaneous value and the current instantaneous value obtained by the replacing module, and taking a high-order power term as a nonlinear impedance characteristic;

and the simulation module simulates the saturation characteristic of the magnetic ring by adopting a voltage-controlled current source, and takes the high-order power term coefficient of the impedance module as the control coefficient of the voltage-controlled current source to realize the simulation of the power frequency saturation characteristic of the single experimental magnetic ring.

In yet another embodiment of the present invention, a terminal device is provided that includes a processor and a memory for storing a computer program comprising program instructions, the processor being configured to execute the program instructions stored by the computer storage medium. The Processor may be a Central Processing Unit (CPU), or may be other general purpose Processor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), an off-the-shelf Programmable gate array (FPGA) or other Programmable logic device, a discrete gate or transistor logic device, a discrete hardware component, etc., which is a computing core and a control core of the terminal, and is adapted to implement one or more instructions, and is specifically adapted to load and execute one or more instructions to implement a corresponding method flow or a corresponding function; the processor provided by the embodiment of the invention can be used for the operation of the magnetic ring power frequency saturation characteristic simulation method, and comprises the following steps:

converting the U-I curve of the magnetic ring into a psi-I curve reflecting the magnetic flux psi of the magnetic ring and the instantaneous current I; fitting the magnetic flux psi and the instantaneous current i according to psi-i curves; replacing the fitted magnetic flux psi with psi ═ udt to obtain the relation between instantaneous voltage value and instantaneous current value; expressing linear impedance by using a first term in a relation between a voltage instantaneous value and a current instantaneous value, and taking a high-order power term as a nonlinear impedance characteristic; the voltage-controlled current source is adopted to simulate the saturation characteristic of the magnetic ring, and the high-order power term coefficient is used as the control coefficient of the voltage-controlled current source, so that the power frequency saturation characteristic simulation of a single experimental magnetic ring is realized.

In still another embodiment of the present invention, the present invention further provides a storage medium, specifically a computer-readable storage medium (Memory), which is a Memory device in a terminal device and is used for storing programs and data. It is understood that the computer readable storage medium herein may include a built-in storage medium in the terminal device, and may also include an extended storage medium supported by the terminal device. The computer-readable storage medium provides a storage space storing an operating system of the terminal. Also, one or more instructions, which may be one or more computer programs (including program code), are stored in the memory space and are adapted to be loaded and executed by the processor. It should be noted that the computer-readable storage medium may be a high-speed RAM memory, or may be a non-volatile memory (non-volatile memory), such as at least one disk memory.

The processor can load and execute one or more instructions stored in the computer readable storage medium to realize the corresponding steps of the simulation method related to the magnetic ring power frequency saturation characteristic in the embodiment; one or more instructions in the computer-readable storage medium are loaded by the processor and perform the steps of:

converting the U-I curve of the magnetic ring into a psi-I curve reflecting the magnetic flux psi of the magnetic ring and the instantaneous current I; fitting the magnetic flux psi and the instantaneous current i according to psi-i curves; replacing the fitted magnetic flux psi with psi ═ udt to obtain the relation between instantaneous voltage value and instantaneous current value; expressing linear impedance by using a first term in a relation between a voltage instantaneous value and a current instantaneous value, and taking a high-order power term as a nonlinear impedance characteristic; the voltage-controlled current source is adopted to simulate the saturation characteristic of the magnetic ring, and the high-order power term coefficient is used as the control coefficient of the voltage-controlled current source, so that the power frequency saturation characteristic simulation of a single experimental magnetic ring is realized.

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, 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 some, but not all, embodiments of the present invention. The components of the embodiments of the present invention generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations. Thus, the following detailed description of the embodiments of the present invention, presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. 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.

Examples

Referring to fig. 3 and 4, a magnetic ring with a length of 20mm, an outer diameter of 50mm and an inner diameter of 30mm is used for testing, the obtained U-I curve is shown in fig. 3, and psi-I curve is obtained by using the U-I curve obtained by testing and adopting a piecewise linearization method, as shown in fig. 4, and can be fitted after the psi-I curve is obtained.

For the saturation characteristic, fitting is carried out on a psi-i curve of the experimental magnetic ring to obtain

i＝150.9895ψ+1.1476×10¹⁵ψ³

Establishing a magnetic ring according to step 5The equivalent circuit of FIG. 5 is obtained by fitting the first coefficient, and the coefficient of the voltage-controlled current source is the coefficient of the higher power coefficient, specifically 1.1476 × 10¹⁵And tested based on the test circuit of fig. 5.

When the saturation characteristic is tested, K1 and K2 in the graph of FIG. 5 are closed, the current source is 50Hz, the amplitude of the current I is changed, a U-I curve can be obtained according to the measured amplitudes of the voltage U and the current I, and compared with the U-I curve obtained by the experiment, as shown in FIG. 6, the simulation is basically coincident with the experiment parameters, which shows that the simulation of the saturation characteristic is basically in accordance with the reality.

And (4) modifying the parameters of the magnetic ring string simulation model formed by the three magnetic rings according to the parameter correction method in the step (6), wherein the U-I curve pair ratio of the experiment and the simulation model is shown in figure 7. Fig. 7 shows that the equivalent model of the saturation characteristic has small relative errors, which indicates that the model is basically in accordance with the reality and can be used for simulation.

In summary, the method and the system for simulating the power frequency saturation characteristic of the magnetic ring provided by the invention realize an equivalent model reflecting the power frequency saturation characteristic of the magnetic ring and perform simulation, so that the saturation characteristic of the magnetic ring under the power frequency is effectively simulated. Meanwhile, model parameters under different sizes and numbers of the magnetic rings are corrected, so that model simulation of the magnetic rings under different sizes and numbers can be realized.

As will be appreciated by one skilled in the art, embodiments of the present application may be provided as a method, system, or computer program product. Accordingly, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present application may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein.

The present application is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the application. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

The above-mentioned contents are only for illustrating the technical idea of the present invention, and the protection scope of the present invention is not limited thereby, and any modification made on the basis of the technical idea of the present invention falls within the protection scope of the claims of the present invention.