A power transmission and transformation complex magnetic field interference equivalent test method

Abstract

This invention discloses an equivalent test method for complex magnetic field interference in power transmission and transformation, comprising: establishing a characteristic dataset of typical magnetic field interference sources; obtaining several groups of interference sources based on the characteristic dataset; programming the output waveforms of programmable signal generator channels of all groups of interference sources according to their characteristic data through a host computer to obtain the first output waveform of each group of interference sources; inputting the first output waveforms of all groups of interference sources into a power amplifier circuit to obtain a second output waveform with increased output power; inputting all groups of second output waveforms into several coils to equivalently simulate various magnetic field interferences with different characteristics within the coils; cascading all coils in space to simulate a complex magnetic field interference environment in a power transmission and transformation scenario; exposing the test object to the complex magnetic field interference environment, conducting performance tests, evaluating the test object's operating performance under complex magnetic field interference, and simulating various magnetic field interference conditions.

Description

Technical Field

[0001] This invention belongs to the field of electromagnetic interference immunity testing technology, specifically relating to an equivalent test method for complex magnetic field interference in power transmission and transformation. Background Technology

[0002] Magnetic sensors are devices that convert the magnitude and changes of magnetic fields into electrical signals. Due to their advantages such as low power consumption, high sensitivity, and miniaturization, they are commonly used in power systems for broadband current measurement, weak current measurement, and AC / DC composite current measurement in transmission and substation scenarios. However, the complex magnetic field interference widely present in transmission and substation scenarios can significantly impact the reliable operation of magnetic sensors. Magnetic field interference sources in transmission and substation scenarios are generally divided into two categories: long-term steady-state magnetic field interference and transient magnetic field interference characterized by high amplitude and wide bandwidth. In actual operating environments of transmission and substation scenarios, multiple magnetic field interference sources are often superimposed, interfering with measurement equipment based on magnetic sensors through capacitive coupling, electromagnetic radiation, and conduction, severely affecting the reliable operation of the measurement equipment. Existing electromagnetic compatibility (EMC) testing methods are all based on single interference sources, failing to consider the superposition of multiple interference sources, and the amplitude and frequency parameters of the interference waveform cannot fully cover the actual field conditions. Therefore, they cannot truly reflect the operating performance of magnetic sensors under actual operating conditions in transmission and substation scenarios. Summary of the Invention

[0003] To address the aforementioned shortcomings in the prior art, the present invention provides an equivalent test method for complex magnetic field interference in power transmission and transformation, which solves the problem that the prior art has a single type of interference source and does not perform equivalent simulation of multiple interference sources superimposed.

[0004] To achieve the above-mentioned objectives, the technical solution adopted by this invention is as follows: an equivalent test method for complex magnetic field interference in power transmission and transformation, comprising the following steps:

[0005] S1. Extract the basic feature parameters of typical magnetic field interference sources in power transmission and substation scenarios, and establish a feature dataset of typical magnetic field interference sources.

[0006] S2. Based on the characteristic dataset of typical magnetic field interference sources, the interference sources are grouped to obtain several groups of interference sources;

[0007] S3. Based on the characteristic data of all groups of interference sources, program the output waveform of the programmable signal generator channel through the host computer to obtain the first output waveform of each group of interference sources.

[0008] S4. Input the first output waveforms of all groups of interference sources into the power amplifier circuit to obtain the second output waveform of each group of first output waveforms after increasing the output power.

[0009] S5. Input all the second output waveforms of the group into several coils respectively, and simulate various magnetic field interferences with different characteristics in the coils.

[0010] S6. Stack all coils in space to simulate the complex magnetic field interference environment in the power transmission and transformation scenario;

[0011] S7. Expose the test sample to a complex magnetic field interference environment and conduct performance tests to evaluate the test sample's operating performance under complex magnetic field interference.

[0012] Furthermore, in S1, the categories of typical magnetic field interference sources include, but are not limited to, power frequency magnetic field interference, DC magnetic field interference, corona discharge magnetic field interference, high-voltage switch opening and closing magnetic field interference, lightning magnetic field interference, short-circuit magnetic field interference, and geomagnetic interference.

[0013] Furthermore: In S1, the basic characteristic parameters of a typical magnetic field interference source include time-domain characteristic parameters and frequency-domain characteristic parameters;

[0014] Among them, the time-domain characteristic parameters include rise time, rise rate, duration, maximum value, peak-to-peak value, peak value, DC component and AC component mean square value;

[0015] Frequency domain characteristic parameters include the upper limit frequency of magnetic field interference, bandwidth, and dominant frequency.

[0016] Furthermore, in S2, the basis for grouping the interference sources is specifically as follows:

[0017] Based on the basic characteristic parameters of typical magnetic field interference sources, they are arranged and combined according to time-domain characteristic parameters and frequency-domain characteristic parameters.

[0018] Furthermore, in S4, the second output waveform is a current waveform.

[0019] Furthermore, in S5, the coil type includes, but is not limited to, a solenoid, a single-turn rectangular coil, a single-turn circular coil, and a Helmholtz coil.

[0020] Furthermore, in S5, adjustable capacitors are connected in series and parallel with the coil to change the impedance value and match it with the characteristic impedance of the transmission line.

[0021] The beneficial effects of the above-mentioned further solutions are: through impedance matching, it can be ensured that all high-frequency signals can be transmitted to the load point, avoiding signal reflection back to the signal source, thereby improving energy efficiency.

[0022] Furthermore, in S6, all coils are spatially nested, and by changing the orientation of any number of coils, the interference magnetic fields from different sources are simulated to achieve vector superposition from different directions.

[0023] The beneficial effect of the above-mentioned further scheme is that by superimposing the coil loops to simulate the vector superposition of magnetic fields in the power transmission and transformation scenario, the complex magnetic field interference environment in the power transmission and transformation scenario can be simulated equivalently.

[0024] The beneficial effects of this invention are as follows: In order to better evaluate the operating status and data impact of magnetic sensors in power transmission and transformation scenarios under magnetic field interference, the equivalent simulation method for complex magnetic field interference of magnetic sensors in power transmission and transformation scenarios proposed in this invention has the following advantages:

[0025] (1) In a small laboratory space, this method can be used to simulate the magnetic field interference environment on site, saving time and cost for magnetic field sensors when conducting magnetic field interference tests.

[0026] (2) This invention can simulate various magnetic field interference situations, such as high-frequency transient magnetic field interference, power frequency magnetic field interference, DC magnetic field interference, irregular waveform magnetic field interference, etc. As long as the digital waveform of magnetic field interference obtained by field measurement is input through a programmable signal generator, high-frequency transient magnetic field interference can be generated in the coil.

[0027] (3) By superimposing coils, this invention can also simulate the environmental situation where complex magnetic field interference exists simultaneously in power transmission and transformation scenarios.

[0028] (4) High-precision equivalent simulation restores the magnetic field interference at the location of the magnetic sensor, ensuring the accuracy of the assessment. Attached Figure Description

[0029] Figure 1 This is a flowchart of an equivalent test method for complex magnetic field interference in power transmission and transformation according to the present invention.

[0030] Figure 2 This is a graph showing the magnetic induction intensity within the coil of the present invention.

[0031] Figure 3 This is a schematic diagram of several coils spatially nested according to the present invention.

[0032] Figure 4 This is a circuit example of the present invention. Detailed Implementation

[0033] The specific embodiments of the present invention are described below to enable those skilled in the art to understand the present invention. However, it should be understood that the present invention is not limited to the scope of the specific embodiments. For those skilled in the art, various changes are obvious as long as they are within the spirit and scope of the present invention as defined and determined by the appended claims. All inventions utilizing the concept of the present invention are protected.

[0034] like Figure 1As shown, in one embodiment of the present invention, a method for equivalent testing of complex magnetic field interference in power transmission and transformation includes the following steps:

[0035] S1. Extract the basic feature parameters of typical magnetic field interference sources in power transmission and substation scenarios, and establish a feature dataset of typical magnetic field interference sources.

[0036] S2. Based on the characteristic dataset of typical magnetic field interference sources, the interference sources are grouped to obtain several groups of interference sources;

[0037] S3. Based on the characteristic data of all groups of interference sources, program the output waveform of the programmable signal generator channel through the host computer to obtain the first output waveform of each group of interference sources.

[0038] S4. Input the first output waveforms of all groups of interference sources into the power amplifier circuit to obtain the second output waveform of each group of first output waveforms after increasing the output power.

[0039] S5. Input all the second output waveforms of the group into several coils respectively, and simulate various magnetic field interferences with different characteristics in the coils.

[0040] S6. Stack all coils in space to simulate the complex magnetic field interference environment in the power transmission and transformation scenario;

[0041] S7. Expose the test sample to a complex magnetic field interference environment and conduct performance tests to evaluate the test sample's operating performance under complex magnetic field interference.

[0042] In S1, the types of typical magnetic field interference sources include, but are not limited to, power frequency magnetic field interference, DC magnetic field interference, corona discharge magnetic field interference, high-voltage switch opening and closing magnetic field interference, lightning magnetic field interference, short-circuit magnetic field interference, and geomagnetic interference.

[0043] In this embodiment, to better simulate the magnetic field interference environment of the magnetic sensor, it is necessary to extract the characteristic parameters of the magnetic field environment at the actual installation location. This is mainly done by measuring with a gaussmeter, and then analyzing the basic characteristic parameters, which are mainly divided into time-domain and frequency-domain characteristic parameters. The magnetic field environment in power transmission and transformation scenarios is quite complex, and the characteristic parameters of various magnetic field interference sources differ. Therefore, the equivalent simulation also requires data analysis of the measured characteristic parameters to decompose the complex magnetic field interference into different types of magnetic field interference waveforms, such as steady-state power frequency interference and high-frequency transient interference.

[0044] In S1, the basic characteristic parameters of a typical magnetic field interference source include time-domain characteristic parameters and frequency-domain characteristic parameters;

[0045] Among them, the time-domain characteristic parameters include rise time, rise rate, duration, maximum value, peak-to-peak value, peak value, DC component and AC component mean square value;

[0046] Frequency domain characteristic parameters include the upper limit frequency of magnetic field interference, bandwidth, and dominant frequency.

[0047] In S2, the basis for grouping the interference sources is as follows:

[0048] Based on the basic characteristic parameters of typical magnetic field interference sources, they are arranged and combined according to time-domain characteristic parameters and frequency-domain characteristic parameters.

[0049] In this embodiment, by extracting the characteristic parameters of the magnetic field interference, the programmable signal generator is programmed with a host computer to output the waveform. MATLAB is primarily used to analyze and sample the digital data of the interference waveform, and the host computer controls the signal generator to output analog data to equivalently simulate the specific waveform of the magnetic field interference. However, since the generation of the magnetic field requires current drive, and the power output of the signal generator is insufficient to drive it, the analog signal needs to be input to a power amplifier circuit for power amplification.

[0050] In S4, the second output waveform is a current waveform.

[0051] In this embodiment, an amplifier circuit is used to increase the amplitude and power of the input signal. Its main task is to ensure that, based on the input signal of the amplifier and while maintaining the characteristic parameters of the input signal, the output signal can drive the load with sufficient current and voltage, so that a sufficient current is passed through the coil to generate a magnetic field inside the coil.

[0052] In S5, the coil type includes, but is not limited to, solenoid, single-turn rectangular coil, single-turn circular coil and Helmholtz coil.

[0053] In step S5, adjustable capacitors are connected in series and parallel with the coil to change the impedance value and match it with the characteristic impedance of the transmission line.

[0054] Impedance matching refers to a working state in which the load impedance and the internal impedance of the excitation source are matched to achieve maximum power output. In a purely resistive circuit, the output power is maximized when the load resistance equals the internal resistance of the excitation source; this working state is called matching. Otherwise, it is called mismatch. When the internal impedance of the excitation source and the load impedance contain reactive components, in order for the load to receive maximum power, the load impedance and internal resistance must satisfy a conjugate relationship, that is, the resistive components are equal, and the absolute values ​​of the reactive components are equal but their signs are opposite. Especially for the equivalent simulation of high-frequency magnetic field interference signals, impedance matching is necessary to ensure that all high-frequency signals can be transmitted to the load point, avoiding signal reflection back to the signal source, thereby improving energy efficiency.

[0055] This method changes the load's impedance by connecting adjustable capacitors in series and parallel with the load, thus matching it to the characteristic impedance of the transmission line. For example... Figure 4 The diagram shows a circuit example of this method, including a host computer, a programmable signal generator, and a power amplifier connected in sequence. The first output terminal of the power amplifier is also connected to one end of a coil and one end of an adjustable capacitor C1 through a load resistor R1. The other end of the coil is connected to one end of a fixed capacitor C2 and one end of an adjustable capacitor C3. The second output terminal of the power amplifier is connected to the other end of the adjustable capacitor C1, the other end of the fixed capacitor C2, and the other end of the adjustable capacitor C3, and is connected to an equipotential potential EP1.

[0056] To better simulate high-frequency magnetic field interference, capacitors are connected in parallel and series on both sides of the coil. R1 is the load resistor, providing protection. C1 and C3 are adjustable capacitors, achieving impedance matching by adjusting their values. C2 is a fixed capacitor, also serving an impedance matching function. L1 is the inductance of the coil, which can be omitted due to its small resistance; therefore, the coil is considered to behave as a pure inductor in the circuit. EP1 represents the equipotential potential.

[0057] In S6, all coils are nested in space. By changing the orientation of any number of coils, the vector superposition of interference magnetic fields from different sources from different directions is simulated.

[0058] In this embodiment, when a current is passed through the coil, a magnetic field is generated inside the coil according to Ampere's circuital law and Faraday's law of electromagnetic induction. The magnitude of the magnetic field is proportional to the current flowing through the coil. Figure 2 The image shows the magnitude and direction of the magnetic field inside and outside the energized coil. It can be seen that the magnetic field inside the coil is relatively uniform.

[0059] Since magnetic field strength is a vector quantity, meaning it has both magnitude and direction, the vector superposition of magnetic fields in power transmission and transformation scenarios can be simulated by superimposing coil loops. This also allows for the equivalent simulation of complex magnetic field interference environments in power transmission and transformation scenarios. Furthermore, the space inside the coil provides a platform for testing magnetic sensors, and the magnetic field is generated within it. Figure 3 The diagram illustrates an example of spatially nested coils, specifically three coils. Each coil is supplied with a current of a different waveform, generating magnetic field interference of varying waveforms within the coils. The magnetic field vectors generated by the three coils are superimposed on a platform inside the coils, providing testing conditions for the magnetic sensor. Therefore, more complex magnetic field interference environments can be simulated by increasing the number of coils.

[0060] The beneficial effects of this invention are as follows: In order to better evaluate the operating status and data impact of magnetic sensors in power transmission and transformation scenarios under magnetic field interference, the equivalent simulation method for complex magnetic field interference of magnetic sensors in power transmission and transformation scenarios proposed in this invention has the following advantages:

[0061] (1) In a small laboratory space, this method can be used to simulate the magnetic field interference environment on site, saving time and cost for magnetic field sensors when conducting magnetic field interference tests.

[0062] (2) This invention can simulate various magnetic field interference situations, such as high-frequency transient magnetic field interference, power frequency magnetic field interference, DC magnetic field interference, irregular waveform magnetic field interference, etc. As long as the digital waveform of magnetic field interference obtained by field measurement is input through a programmable signal generator, high-frequency transient magnetic field interference can be generated in the coil.

[0063] (3) By superimposing coils, this invention can also simulate the environmental situation where complex magnetic field interference exists simultaneously in power transmission and transformation scenarios.

[0064] (4) High-precision equivalent simulation restores the magnetic field interference at the location of the magnetic sensor, ensuring the accuracy of the assessment.

[0065] In the description of this invention, it should be understood that the terms "center," "thickness," "upper," "lower," "horizontal," "top," "bottom," "inner," "outer," and "radial," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying the relative importance or the number of technical features implicitly specified. Therefore, a feature defined by "first," "second," and "third" may explicitly or implicitly include one or more of that feature.

Claims

1. A method for equivalent testing of complex magnetic field interference in power transmission and transformation, characterized in that, Includes the following steps: S1. Extract the basic feature parameters of typical magnetic field interference sources in power transmission and substation scenarios, and establish a feature dataset of typical magnetic field interference sources. S2. Based on the characteristic dataset of typical magnetic field interference sources, the interference sources are grouped to obtain several groups of interference sources; S3. Based on the characteristic data of all groups of interference sources, program the output waveform of the programmable signal generator channel through the host computer to obtain the first output waveform of each group of interference sources. S4. Input the first output waveforms of all groups of interference sources into the power amplifier circuit to obtain the second output waveform of each group of first output waveforms after increasing the output power; the second output waveform is a current waveform. S5. Input all the second output waveforms of the group into several coils respectively, and simulate various magnetic field interferences with different characteristics in the coils. The coil types include, but are not limited to, solenoids, single-turn rectangular coils, single-turn circular coils and Helmholtz coils. Connect adjustable capacitors in series and parallel to the coils to change the impedance value and match it with the characteristic impedance of the transmission line. S6. All coils are spatially nested to simulate the complex magnetic field interference environment in power transmission and transformation scenarios; All coils are spatially nested, and by changing the orientation of any coil, the vector superposition of interference magnetic fields from different sources from different directions is simulated. S7. Expose the test sample to a complex magnetic field interference environment and conduct performance tests to evaluate the test sample's operating performance under complex magnetic field interference.

2. The equivalent test method for complex magnetic field interference in power transmission and transformation according to claim 1, characterized in that, In S1, the types of typical magnetic field interference sources include, but are not limited to, power frequency magnetic field interference, DC magnetic field interference, corona discharge magnetic field interference, high-voltage switch opening and closing magnetic field interference, lightning magnetic field interference, short-circuit magnetic field interference, and geomagnetic interference.

3. The equivalent test method for complex magnetic field interference in power transmission and transformation according to claim 2, characterized in that, In S1, the basic characteristic parameters of a typical magnetic field interference source include time-domain characteristic parameters and frequency-domain characteristic parameters; Among them, the time-domain characteristic parameters include rise time, rise rate, duration, maximum value, peak-to-peak value, peak value, DC component and AC component mean square value; Frequency domain characteristic parameters include the upper limit frequency of magnetic field interference, bandwidth, and dominant frequency.

4. The equivalent test method for complex magnetic field interference in power transmission and transformation according to claim 3, characterized in that, In S2, the basis for grouping the interference sources is as follows: Based on the basic characteristic parameters of typical magnetic field interference sources, they are arranged and combined according to time-domain characteristic parameters and frequency-domain characteristic parameters.

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