Model construction method and testing method for two closely-spaced dry-type air-core reactors

Abstract

The present invention discloses a method for constructing a model and a testing method for two closely-spaced dry-type air-core reactors. After converting the actual application scenario into a mathematical model, actual parameters are collected and substituted into the model for parameter testing. This avoids errors caused by simply calculating based on the equipment parameter nameplate without considering the influence of the actual environment, and can help debuggers conveniently and quickly measure the mutual inductance value of the dry-type air-core reactor on-site in the power industry such as substations and converter stations. Without the need to rely on high-voltage equipment and variable-frequency voltage sources, the corresponding resistance, current, and voltage of the dry-type air-core reactor to be measured are measured in four steps, and then the mutual inductance value of the dry-type air-core reactor can be measured. Through the method provided by the present invention, the measured mutual inductance value takes into account the errors of the surrounding environment and installation errors on the calculation, and is closer to the true value.

Description

Technical Field

[0001] The present invention relates to the field of electrical equipment parameter detection, and specifically to a method for constructing a model and a testing method for two closely spaced dry-type air-core reactors. Background Art

[0002] In the same environment, the phase spacing between dry-type air-core reactors is usually 1.7 times the outer diameter of the reactor (1.7D). When the installation distance is reduced, the magnetic field intensity around the reactor will change, thereby affecting its electrical parameters. For example, in the 500 kV filter field of a converter station, when the phase spacing of the reactor installation does not meet the requirements, its mutual inductance value cannot be ignored, which will change the designed filtering effect. Therefore, it is necessary to carry out various parameter tests on dry-type air-core reactors at the power site to determine whether the design parameters meet the design requirements. Summary of the Invention

[0003] The purpose of the present invention is to provide a method for constructing a model and a testing method for two closely spaced dry-type air-core reactors. After converting the actual application scenario into a mathematical model, actual parameters are collected and substituted into the model for parameter testing. This avoids errors caused by simply calculating through the equipment parameter nameplate without considering the influence of the actual environment, and can help debuggers conveniently and quickly measure the mutual inductance value of dry-type air-core reactors at power industry sites such as substations and converter stations.

[0004] The present invention is achieved through the following technical solutions:

[0005] In a first aspect, the present invention provides a method for constructing a parameter model of two closely spaced dry-type air-core reactors, including:

[0006] Arrange a first dry-type air-core reactor and a second dry-type air-core reactor at a preset distance on the same horizontal plane;

[0007] Arrange a basic acquisition device. The basic acquisition device is respectively connected to each dry-type air-core reactor for collecting the resistance of the first dry-type air-core reactor and the second dry-type air-core reactor; the other end of the basic acquisition device is connected to a processing unit;

[0008] Arrange a power acquisition device. The power acquisition device is respectively connected to each dry-type air-core reactor for collecting the power parameters of the first dry-type air-core reactor and the second dry-type air-core reactor; the other end of the power acquisition device is connected to a processing unit;

[0009] Construct an equivalent circuit parameter model of the first dry-type air-core reactor and the second dry-type air-core reactor in the same time and space through the operating parameters of the two dry-type air-core reactors to be tested obtained by the processing unit.

[0010] As an alternative embodiment of the present invention, it further includes arranging a power frequency voltage source, and before the power acquisition device performs acquisition, connecting the two ends of the winding of each dry-type air-core reactor to the power frequency voltage source respectively.

[0011] As an alternative embodiment of the present invention, the equivalent circuit parameter model includes parameter current, resistance, voltage, inductance, and mutual inductance.

[0012] As an alternative embodiment of the present invention, after the processing unit collects the operating parameters of two dry-type air-core reactors, it outputs an equivalent circuit parameter model:

[0013]

[0014] Wherein, is the voltage value of the first dry-type air-core reactor, L1 is the inductance value of the first dry-type air-core reactor, ωL1 is the impedance value of the first dry-type air-core reactor at a specific frequency, R1 is the resistance value of the first dry-type air-core reactor, is the current value of the first dry-type voltage transformer; is the voltage value of the second dry-type air-core reactor, L2 is the inductance value of the second dry-type air-core reactor, ωL2 is the impedance value of the second dry-type air-core reactor at a specific frequency, R2 is the resistance value of the second dry-type air-core reactor, is the current value of the second dry-type voltage transformer; M is the mutual inductance value between the first dry-type air-core reactor and the second dry-type air-core reactor.

[0015] In a second aspect, the present invention provides a method for testing the parameters of two closely spaced dry-type air-core reactors, including:

[0016] Obtaining the operating parameters of a first dry-type air-core reactor and a second dry-type air-core reactor that are closely spaced in the same space-time;

[0017] Inputting the operating parameters into the equivalent circuit parameter model to obtain the parameter results of the first dry-type air-core reactor and the second dry-type air-core reactor; the equivalent circuit parameter model is obtained by using the parameter model construction method of two closely spaced dry-type air-core reactors as described above.

[0018] As an alternative embodiment of the present invention, obtaining the operating parameters of a first dry-type air-core reactor and a second dry-type air-core reactor that are closely spaced in the same space-time includes the following steps:

[0019] Collecting the resistance values R1 and R2 of the first dry-type air-core reactor and the second dry-type air-core reactor through a basic acquisition device;

[0020] Connect one end of the winding of the first dry-type air-core reactor to the first end of the power frequency voltage source, connect one end of the winding of the second dry-type air-core reactor to the second end of the power frequency voltage source and form an open circuit, and obtain the voltage U1 and current I1 of the first dry-type air-core reactor through the power acquisition device;

[0021] Connect one end of the winding of the second dry-type air-core reactor to the first end of the power frequency voltage source, connect one end of the winding of the first dry-type air-core reactor to the second end of the power frequency voltage source and form an open circuit, and obtain the voltage U2 and current I2 of the second dry-type air-core reactor through the power acquisition device,

[0022] Connect one end of the winding of the first dry-type air-core reactor to the first end of the power frequency power supply, connect one end of the winding of the second dry-type air-core reactor to the second end of the power frequency voltage source and form a short circuit, and obtain the voltage U11 and current I11 of the first dry-type air-core reactor through the power acquisition device. As an alternative embodiment of the present invention, inputting the operating parameters into the equivalent circuit parameter model to obtain the parameter results of the first dry-type air-core reactor and the second dry-type air-core reactor includes the following steps:

[0023] Input the voltage U1 and current I1 of the first dry-type air-core reactor into the equivalent circuit parameter model to obtain the inductance L1 of the first dry-type air-core reactor;

[0024] Input the voltage U2 and current I2 of the second dry-type air-core reactor into the equivalent circuit parameter model to obtain the inductance L2 of the second dry-type air-core reactor;

[0025] Input the voltage U11 and current I11 of the first dry-type air-core reactor into the equivalent circuit parameter model to obtain the mutual inductance value M of the first dry-type air-core reactor and the second dry-type air-core reactor.

[0026] As an alternative embodiment of the present invention, the basic acquisition device uses a high-precision multimeter.

[0027] As an alternative embodiment of the present invention, the power acquisition device uses a power analyzer.

[0028] As an alternative embodiment of the present invention, the distance between the geometric center connections of the first dry-type air-core reactor and the second dry-type air-core reactor is less than 1.7 times the outer diameter of any one dry-type air-core reactor.

[0029] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0030] The present invention can measure the mutual inductance value of a dry-type air-core reactor to be measured by measuring the corresponding resistance, current and voltage of the dry-type air-core reactor in four steps without relying on high-voltage equipment and a variable-frequency voltage source. This method can be used in laboratories and also in on-site power commissioning. Compared with calculating the mutual inductance value using the nameplate parameters of the dry-type air-core reactor and the distance between two current transformers with a general formula, this method cannot take into account the influence of surrounding equipment on the dry-type air-core reactor and the influence of installation errors on the mutual inductance value, and the calculated mutual inductance value is the value in an ideal environment. Through the method provided by the present invention, the measured mutual inductance value takes into account the influence of the surrounding environment and installation errors on the calculation error and is closer to the true value. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The drawings described herein are used to provide a further understanding of the embodiments of the present invention, form a part of this application, and do not limit the embodiments of the present invention. In the drawings:

[0032] Figure 1 is a schematic flow chart of a method for constructing a parameter model of two closely-spaced dry-type air-core reactors provided by an embodiment of the present invention;

[0033] Figure 2 is a schematic flow chart of a method for testing the parameters of two closely-spaced dry-type air-core reactors provided by an embodiment of the present invention;

[0034] Figure 3 is an equivalent circuit diagram of the parameter model of two closely-spaced dry-type air-core reactors provided by an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0035] To make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below in conjunction with the embodiments and the drawings. The illustrative embodiments and descriptions thereof of the present invention are only used to explain the present invention and do not limit the present invention.

[0036] Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed present invention, but merely represents selected embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the scope of protection of the present invention.

[0037] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the inventive product is customarily placed during use. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the present invention. In addition, the terms "first", "second", "third", etc. are only used for distinguishing descriptions and should not be construed as indicating or implying relative importance.

[0038] In the description of the present invention, it should also be noted that unless otherwise clearly specified and defined, the terms "set", "install", "connect", and "couple" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0039] Embodiment 1

[0040] The dry-type air-core reactor adopts a multi-layer parallel cylindrical structure. That is, a single-layer coil is wound on a winding mold with thinner insulated aluminum wire, and multiple single-layer coils are wrapped with long glass fiber bundles impregnated with epoxy resin to form a package. Then, multiple packages are coaxially stacked on this package in sequence, and the packages are separated and supported by resin glass fiber pultruded bars to form an axial heat dissipation air duct. After winding, it is cured to form a solid whole. The phase spacing of its installation is usually 1.7 times the outer diameter of the reactor (1.7D). When the installation distance is reduced, the magnetic field intensity around the reactor will change, thereby affecting its electrical parameters. For example, in the 500 kV filter field of a converter station, when the phase spacing of the reactor installation does not meet the requirements, its mutual inductance value cannot be ignored, and it will change the designed filtering effect.

[0041] Please refer to Figure 1, this embodiment provides a method for constructing a parameter model of two closely - spaced dry - type air - core reactors, including: arranging a first dry - type air - core reactor and a second dry - type air - core reactor at a preset distance on the same horizontal plane; arranging a basic acquisition device, where the basic acquisition device is respectively connected to each of the dry - type air - core reactors for collecting the resistance of the first dry - type air - core reactor and the second dry - type air - core reactor; the other end of the basic acquisition device is connected to a processing unit; arranging a power acquisition device, where the power acquisition device is respectively connected to each of the dry - type air - core reactors for collecting the power parameters of the first dry - type air - core reactor and the second dry - type air - core reactor; the other end of the power acquisition device is connected to the processing unit; obtaining the operating parameters of the two dry - type air - core reactors to be measured through the processing unit, and constructing an equivalent - circuit parameter model of the first dry - type air - core reactor and the second dry - type air - core reactor under the same time - space. The equivalent - circuit parameter model includes parameter current, resistance, voltage, inductance, and mutual inductance. Before the power acquisition device collects data, the two ends of the winding of each dry - type air - core reactor are respectively connected to the power - frequency voltage source.

[0042] In this embodiment, the processing unit can be a on - site computer terminal or a single - chip microcomputer computing device, which is used to organize and output the equivalent - circuit parameter model for the collected parameters:

[0043]

[0044] Among them, is the voltage value of the first dry - type air - core reactor, L1 is the inductance value of the first dry - type air - core reactor, ωL1 is the impedance value of the first dry - type air - core reactor at a specific frequency, R1 is the resistance value of the first dry - type air - core reactor, is the current value of the first dry - type voltage transformer; is the voltage value of the second dry - type air - core reactor, L2 is the inductance value of the second dry - type air - core reactor, ωL2 is the impedance value of the second dry - type air - core reactor at a specific frequency, R2 is the resistance value of the second dry - type air - core reactor, is the current value of the second dry - type voltage transformer; M is the mutual inductance value between the first dry - type air - core reactor and the second dry - type air - core reactor.

[0045] In the second aspect, this embodiment also provides a method for testing the parameters of two closely - spaced dry - type air - core reactors, obtaining the operating parameters of the first dry - type air - core reactor and the second dry - type air - core reactor that are closely spaced in the same time - space; inputting the operating parameters into the equivalent - circuit parameter model to obtain the parameter results of the first dry - type air - core reactor and the second dry - type air - core reactor; the equivalent - circuit parameter model is obtained by using the parameter - model construction method of the two closely - spaced dry - type air - core reactors as described above. This embodiment is implemented as follows:

[0046] Select a high-precision multimeter such as the FLUKE 289C industrial multimeter as the basic acquisition device. After selecting a common multi-channel power analyzer on the market as the power acquisition device, then collect the resistance values R1 and R2 of the first dry-type air-core reactor and the second dry-type air-core reactor through the high-precision multimeter.

[0047] Then connect the two ends a and b of the winding of the first dry-type air-core reactor to the first end of the industrial frequency voltage source, the AC mains. Connect the two ends c and d of the winding of the second dry-type air-core reactor to the second end of the industrial frequency voltage source and form an open circuit. Obtain the voltage U1 and current I1 of the first dry-type air-core reactor through the power analyzer.

[0048] Connect the two ends c and d of the winding of the second dry-type air-core reactor to the first end of the industrial frequency voltage source, the AC mains. Connect the two ends a and b of the winding of the first dry-type air-core reactor to the second end of the industrial frequency voltage source and form an open circuit. Obtain the voltage U2 and current I2 of the second dry-type air-core reactor through the power analyzer.

[0049] Connect the two ends a and b of the winding of the first dry-type air-core reactor to the first end of the industrial frequency power supply, and connect the two ends c and d of the winding of the second dry-type air-core reactor to the second end of the industrial frequency voltage source and form a short circuit. Obtain the voltage and current

[0050] Then, input the voltage U1 and current I1 of the first dry-type air-core reactor into the equivalent circuit parameter model to obtain the inductance L1 of the first dry-type air-core reactor:

[0051]

[0052] Input the voltage U2 and current I2 of the second dry-type air-core reactor into the equivalent circuit parameter model to obtain the inductance L2 of the second dry-type air-core reactor:

[0053]

[0054] The voltage and current of the first dry-type air-core reactor are input into the equivalent circuit parameter model to obtain the mutual inductance value M of the first dry-type air-core reactor and the second dry-type air-core reactor:

[0055]

[0056] Example 2

[0057] This embodiment provides an instantiated scenario to verify the model construction method and testing method of the two closely-spaced dry-type air-core reactors described in the above embodiment.

[0058] Two dry-type air-core reactors are separated by a distance of d meters, and the designed values of their respective resistances, inductances, and mutual inductances are as shown in the following table.

[0059]

[0060] First, select a power frequency alternating current with a voltage source of 50 Hz, so ω = 2πf = 314. Use a high-precision multimeter to measure the DC resistance value of the first dry-type air-core reactor, and convert it to the DC resistance value R1 at 26°C, which is 0.0378 Ω; similarly, measure the DC resistance value R2 of the second dry-type air-core reactor, which is 0.0378 Ω.

[0061] Secondly, according to the steps described in the above Embodiment 1, use a power analyzer to measure the current and voltage phasors as shown in the following table.

[0062]

[0063] Then, calculate the inductance value L1 of the first dry-type air-core reactor.

[0064]

[0065] Then calculate the inductance value L2 of the second dry-type air-core reactor.

[0066]

[0067] Finally, calculate the mutual inductance value M between the first dry-type air-core reactor and the second dry-type air-core reactor.

[0068]

[0069] The calculated values of L1, L2, and M are within the expected error range compared with the designed values.

[0070] The above-described specific implementation manners further elaborate on the purpose, technical solutions, and beneficial effects of the present invention. It should be understood that the above is only the specific implementation manners of the present invention and is not used to limit the protection scope of the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A method for constructing a parameter model of two closely spaced dry-type air-core reactors, characterized in that Including: Arranging two first dry-type air-core reactors and second dry-type air-core reactors which are arranged at a preset distance on the same horizontal plane; Arranging a basic acquisition device which is respectively connected to each of the dry-type air-core reactors for acquiring the resistance of the first dry-type air-core reactor and the second dry-type air-core reactor; the other end of the basic acquisition device is connected to a processing unit; Arranging a power acquisition device which is respectively connected to each of the dry-type air-core reactors for acquiring the power parameters of the first dry-type air-core reactor and the second dry-type air-core reactor; the other end of the power acquisition device is connected to a processing unit; The distance between the geometric center connection lines of the first dry-type air-core reactor and the second dry-type air-core reactor is less than 1.7 times the outer diameter of any one dry-type air-core reactor; Based on the operation parameters of the two dry-type air-core reactors to be measured obtained by the processing unit, constructing an equivalent circuit parameter model of the first dry-type air-core reactor and the second dry-type air-core reactor in the same time and space; The equivalent circuit parameter model includes parameter current, resistance, voltage, inductance and mutual inductance; After the processing unit collects the operation parameters of the two dry-type air-core reactors, outputting the equivalent circuit parameter model: Among them, is the voltage value of the first dry-type air-core reactor, is the inductance value of the first dry-type air-core reactor, is the impedance value of the first dry-type air-core reactor at a specific frequency, is the resistance value of the first dry-type air-core reactor, is the current value of the first dry-type voltage transformer; is the voltage value of the second dry-type air-core reactor, is the inductance value of the second dry-type air-core reactor, is the impedance value of the second dry-type air-core reactor at a specific frequency, is the resistance value of the second dry-type air-core reactor, is the current value of the second dry-type voltage transformer; is the mutual inductance value between the first dry-type air-core reactor and the second dry-type air-core reactor.

2. The parameter model construction method for two closely - spaced dry - type air - core reactors according to claim 1, characterized in that, It further includes arranging a power frequency voltage source, and before the power acquisition device acquires data, connecting the two ends of the winding of each dry-type air-core reactor to the power frequency voltage source respectively.

3. A parameter testing method for two closely - spaced dry - type air - core reactors, characterized in that, Including: Obtaining the operation parameters of the first dry-type air-core reactor and the second dry-type air-core reactor which are closely located in the same time and space; Inputting the operation parameters into the equivalent circuit parameter model to obtain the parameter results of the first dry-type air-core reactor and the second dry-type air-core reactor; the equivalent circuit parameter model is obtained by using the parameter model construction method of the two closely located dry-type air-core reactors as described in any one of the above claims 1-2; Obtaining the operation parameters of the first dry-type air-core reactor and the second dry-type air-core reactor which are closely located in the same time and space includes the following steps: Collecting the resistance values R1 and R2 of the first dry-type air-core reactor and the second dry-type air-core reactor through the basic acquisition device; Connecting one end of the winding of the first dry-type air-core reactor to the first end of the power frequency voltage source, connecting one end of the winding of the second dry-type air-core reactor to the second end of the power frequency voltage source and forming an open circuit, and obtaining the voltage U1 and current I1 of the first dry-type air-core reactor through the power acquisition device; Connecting one end of the winding of the second dry-type air-core reactor to the first end of the power frequency voltage source, connecting one end of the winding of the first dry-type air-core reactor to the second end of the power frequency voltage source and forming an open circuit, and obtaining the voltage U2 and current I2 of the second dry-type air-core reactor through the power acquisition device; Connecting one end of the winding of the first dry-type air-core reactor to the first end of the power frequency power supply, connecting one end of the winding of the second dry-type air-core reactor to the second end of the power frequency voltage source and forming a short circuit, and obtaining the voltage U11 and current I11 of the first dry-type air-core reactor through the power acquisition device; Inputting the operation parameters into the equivalent circuit parameter model to obtain the parameter results of the first dry-type air-core reactor and the second dry-type air-core reactor includes the following steps: Input the voltage U1 and current I1 of the first dry-type air-core reactor into the equivalent circuit parameter model to obtain the inductance L1 of the first dry-type air-core reactor; Input the voltage U2 and current I2 of the second dry-type air-core reactor into the equivalent circuit parameter model to obtain the inductance L2 of the second dry-type air-core reactor; Input the voltage U11 and current I11 of the first dry-type air-core reactor into the equivalent circuit parameter model to obtain the mutual inductance value M between the first dry-type air-core reactor and the second dry-type air-core reactor.

4. A parameter testing method for two closely - spaced dry - type air - core reactors according to claim 3, characterized in that, The basic acquisition device uses a high-precision multimeter.

5. A parameter testing method for two closely-spaced dry-type air-core reactors according to claim 3, characterized in that The power acquisition device uses a power analyzer.

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