Power transmission and transformation complex magnetic field interference equivalent test method

Abstract

The invention discloses a power transmission and transformation complex magnetic field interference equivalent test method. The method comprises the following steps: establishing a typical magnetic field interference source characteristic data set; obtaining a plurality of groups of interference sources based on the typical magnetic field interference source feature data set; respectively programming the output waveforms of the channels of the programmable signal generator through an upper computer according to the characteristic data of all groups of interference sources to obtain a first output waveform of each group of interference sources; inputting the first output waveforms of all groups of interference sources into a power amplification circuit to obtain a second output waveform after the output power is increased; respectively inputting all groups of second output waveforms into a plurality of coils, and equivalently simulating various magnetic field interferences with different characteristics in the plurality of coils; all coils are telescoped in space, and a complex magnetic field interference environment in a power transmission and transformation scene is simulated; the tested object is exposed in a complex magnetic field interference environment, a performance test is carried out, the operation performance of the tested object under complex magnetic field interference is evaluated, and simulation of various magnetic field interference conditions is realized.

Description

Technical Field

[0001] The invention belongs to the technical field of electromagnetic interference immunity test, and specifically relates to an equivalent test method for complex magnetic field interference of power transmission and transformation. Background Art

[0002] A magnetic sensor is a device that can convert the size and change of a magnetic field into an electrical signal. Due to its advantages of low power consumption, high sensitivity, and miniaturization, it is often used in power systems in broadband current measurement, weak current measurement, AC / DC composite current measurement, and other fields in power transmission and transformation scenarios. However, the complex magnetic field interference that is widely present in power transmission and transformation scenarios will have a significant impact on the reliable operation of magnetic sensors. The magnetic field interference sources in the transmission and transformation scenarios are often divided into two categories: one is the long-term steady-state magnetic field interference, and the other is the transient magnetic field interference with high amplitude and wide bandwidth. In the actual operating environment of the power transmission and transformation scenario, there are usually multiple magnetic field interference sources superimposed, and through capacitive and inductive coupling, electromagnetic radiation, conduction, etc., they interfere with the measurement equipment designed based on magnetic sensors, seriously affecting the reliable operation of the measurement equipment. The existing electromagnetic compatibility test methods are all based on a single interference source for testing, without considering the superposition of multiple interference sources, and the parameters such as the amplitude and frequency of the interference waveform cannot fully cover the actual situation on site, so it is impossible to truly reflect the operating performance of the magnetic sensor under the actual working conditions of the power transmission and transformation scenario. Summary of the invention

[0003] In view of the above-mentioned deficiencies in the prior art, the present invention provides a power transmission and transformation complex magnetic field interference equivalent test method which solves the problem in the prior art that the interference source type is single and equivalent simulation of multiple interference sources superposition is not performed.

[0004] In order to achieve the above-mentioned invention object, the technical solution adopted by the present invention is: a complex magnetic field interference equivalent test method for power transmission and transformation, comprising the following steps:

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

[0006] S2. Based on a typical magnetic field interference source feature data set, the interference sources are grouped to obtain several groups of interference sources;

[0007] S3, programming the output waveforms of the programmable signal generator channels of all groups of interference sources according to their characteristic data through the host computer, to obtain the first output waveform of each group of interference sources;

[0008] S4, inputting the first output waveforms of all groups of interference sources into a power amplification circuit to obtain a second output waveform of each group of first output waveforms with increased output power;

[0009] S5, inputting all groups of second output waveforms into a plurality of coils respectively, and equivalently simulating magnetic field interferences with various characteristics inside the plurality of coils;

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

[0011] S7. Expose the test product to a complex magnetic field interference environment, conduct performance test, and evaluate the operating performance of the test product under complex magnetic field interference.

[0012] Further: 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 magnetic field interference, lightning magnetic field interference, short-circuit magnetic field interference and geomagnetic interference.

[0013] Further: in said S1, the basic characteristic parameters of the 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] The frequency domain characteristic parameters include the upper limit frequency, bandwidth and dominant frequency of the magnetic field interference.

[0016] Further: In S2, the basis for grouping the interference sources is specifically:

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

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

[0019] Further: in S5, the coil types include but are not limited to solenoids, single-turn rectangular coils, single-turn circular coils and Helmholtz coils.

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

[0021] The beneficial effect of the above further solution is that, through impedance matching, it can be ensured that all high-frequency signals can be transmitted to the load point, avoiding the signal from being reflected back to the signal source, thereby improving energy efficiency.

[0022] Furthermore: in S6, all coils are overlapped in space, and by changing the orientation of any coil, interfering magnetic fields from different sources are simulated to achieve vector superposition from different directions.

[0023] The beneficial effect of the above further scheme is: by simulating the vector superposition of the magnetic field in the power transmission and transformation scenario through the loop superposition of the coils, the complex magnetic field interference environment in the power transmission and transformation scenario can be equivalently simulated.

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

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

[0026] (2) The present invention can simulate a variety of magnetic field interference conditions, 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 magnetic field interference digital waveform 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) The present invention can also simulate the environment where complex magnetic field interference coexists in power transmission and transformation scenarios by stacking coil loops.

[0028] (4) High-precision equivalent simulation restores the magnetic field interference at the location of the magnetic sensitive sensor to ensure the accuracy of the assessment. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 The present invention is a flow chart of a method for equivalent testing of complex magnetic field interference in power transmission and transformation.

[0030] Figure 2 It is a curve diagram of magnetic induction intensity in the coil of the present invention.

[0031] Figure 3 It is a schematic diagram of the spatial overlapping of several coils of the present invention.

[0032] Figure 4 This is a circuit example of the present invention. DETAILED DESCRIPTION

[0033] The specific implementation modes of the present invention are described below so that those skilled in the art can understand the present invention. However, it should be clear that the present invention is not limited to the scope of the specific implementation modes. For those of ordinary skill in the art, as long as various changes are within the spirit and scope of the present invention as defined and determined by the attached claims, these changes are obvious, and all inventions and creations 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 test of complex magnetic field interference of power transmission and transformation includes the following steps:

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

[0036] S2. Based on a typical magnetic field interference source feature data set, the interference sources are grouped to obtain several groups of interference sources;

[0037] S3, programming the output waveforms of the programmable signal generator channels of all groups of interference sources according to their characteristic data through the host computer, to obtain the first output waveform of each group of interference sources;

[0038] S4, inputting the first output waveforms of all groups of interference sources into a power amplification circuit to obtain a second output waveform of each group of first output waveforms with increased output power;

[0039] S5, inputting all groups of second output waveforms into a plurality of coils respectively, and equivalently simulating magnetic field interferences with various characteristics inside the plurality of coils;

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

[0041] S7. Expose the test product to a complex magnetic field interference environment, conduct performance test, and evaluate the operating performance of the test product under complex magnetic field interference.

[0042] 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 magnetic field interference, lightning magnetic field interference, short-circuit magnetic field interference and geomagnetic interference.

[0043] In this embodiment, in order to better simulate the magnetic field interference environment in which the magnetic sensitive sensor is located, it is necessary to extract the characteristic parameters of the magnetic field environment in the actual installation environment, mainly through the Gauss meter for measurement, and perform data analysis on its basic characteristic parameters after measurement, which are mainly divided into time domain characteristic parameters and frequency domain characteristic parameters. The magnetic field environment of the power transmission and transformation scenario is relatively complex, and there are differences in the characteristic parameters of various magnetic field interference sources. Therefore, it is also necessary to perform data analysis on the measured characteristic parameters during equivalent simulation, and decompose the complex magnetic field interference into different types of magnetic field interference waveforms, such as steady-state power frequency interference, high-frequency transient interference, etc.

[0044] In S1, the basic characteristic parameters of the 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] The frequency domain characteristic parameters include the upper limit frequency, bandwidth and dominant frequency of the magnetic field interference.

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

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

[0049] In this embodiment, by extracting the characteristic parameters of magnetic field interference, the programmable signal generator is programmed to output waveforms through the host computer, the interference waveform is mainly analyzed and sampled by digital data through MATLAB, and the host computer controls the signal generator to output analog data to equivalently simulate the specific waveform of magnetic field interference. However, since the generation of magnetic field requires current drive, the power output of the signal generator is not enough to drive, so it is necessary to input the analog signal into the 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 the output signal can drive the load with sufficient current and voltage based on the input signal of the amplifier while maintaining the characteristic parameters of the input signal, so that a current of sufficient power flows into the coil and a magnetic field is generated inside the coil.

[0052] In S5, the coil types include but are not limited to solenoids, single-turn rectangular coils, single-turn circular coils and Helmholtz coils.

[0053] In S5, adjustable capacitors are connected in series and in parallel to 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 adapted to each other to achieve maximum power output. In a pure resistance circuit, when the load resistance is equal to the internal resistance of the excitation source, the output power is maximum, and this working state is called matching; otherwise it is called mismatching. When the internal impedance of the excitation source and the load impedance contain reactance components, in order to obtain the maximum power of the load, the load impedance and the internal resistance must satisfy a conjugate relationship, that is, the resistance components are equal, and the reactance components have the same absolute value but opposite signs. In particular, for the equivalent simulation of high-frequency magnetic field interference signals, impedance matching is required to ensure that all high-frequency signals can be transmitted to the load point, avoid signal reflection back to the signal source, and thus improve energy efficiency.

[0055] This method changes the impedance value of the load by connecting adjustable capacitors in series and in parallel to the load to match the characteristic impedance of the transmission line. Figure 4 As shown, it is a circuit example of the present method, including a host computer, a programmable signal generator and a power amplifier connected in sequence, the first output end of the power amplifier is also connected to one end of the coil and one end of the adjustable capacitor C1 respectively through a load resistor R1, the other end of the coil is connected to one end of the fixed capacitor C2 and one end of the adjustable capacitor C3 respectively, the second output end 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 respectively, and is connected to the equipotential EP1;

[0056] In order to better simulate high-frequency magnetic field interference, capacitors are connected in parallel and in series on both sides of the coil, where R1 is the load resistor, which plays a protective role, C1 and C3 are adjustable capacitors, which achieve impedance matching by adjusting the capacitance, C2 is a fixed capacitor, which also plays an impedance matching role, and L1 is the inductance value of the coil. Since the resistance of the coil is small, it can be omitted, so it is considered that the coil behaves as a pure inductor in the circuit. EP1 is the equipotential position.

[0057] In S6, all coils are overlapped in space, and by changing the orientation of any coil, interfering magnetic fields from different sources are simulated to achieve vector superposition from different directions.

[0058] In this embodiment, when current is passed through the coil, a magnetic field is generated inside the coil according to Ampere's circuit theorem and Faraday's law of electromagnetic induction. The magnitude of the magnetic field is proportional to the current passing through the coil. Figure 2 The figure shows the size 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 the magnetic field strength is a vector, that is, it has magnitude and direction, the vector superposition of the magnetic field in the power transmission and transformation scenario can be simulated by superimposing the coil loops, and the complex magnetic field interference environment in the power transmission and transformation scenario can be equivalently simulated. In addition, the space inside the coil provides a platform space for the test of the magnetic sensor, and the magnetic field is also generated inside it. Figure 3 The figure shows an example of several coils overlapping in space, where three coils overlap in space. When currents of different waveforms are passed through the three coils, magnetic field interferences of different waveforms can be generated inside the three coils. The magnetic field vectors generated by the three coils are superimposed on the placement platform inside the coils, providing test conditions for the magnetic sensor. Therefore, a more complex magnetic field interference environment can be simulated by increasing the number of coils.

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

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

[0062] (2) The present invention can simulate a variety of magnetic field interference conditions, 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 magnetic field interference digital waveform 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) The present invention can also simulate the environment where complex magnetic field interference coexists in power transmission and transformation scenarios by stacking coil loops.

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

[0065] In the description of the present invention, it is necessary to understand that the orientation or positional relationship indicated by the terms "center", "thickness", "upper", "lower", "horizontal", "top", "bottom", "inner", "outer", "radial", etc. is based on the orientation or positional relationship shown in the drawings, and 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 cannot be understood as a limitation on the present invention. In addition, the terms "first", "second", and "third" are used only for descriptive purposes, and cannot be understood as indicating or implying the relative importance or the number of implicitly specified technical features. Therefore, the features defined by "first", "second", and "third" may explicitly or implicitly include one or more of the features.

Claims

1. A method for equivalent test of complex magnetic field interference in power transmission and transformation, characterized in that: The following steps are involved: S1. Extract the basic characteristic parameters of typical magnetic field interference sources in power transmission and substation scenarios, and establish a characteristic data set of typical magnetic field interference sources; S2. Based on a typical magnetic field interference source feature data set, the interference sources are grouped to obtain several groups of interference sources; S3, programming the output waveforms of the programmable signal generator channels of all groups of interference sources according to their characteristic data through the host computer, to obtain the first output waveform of each group of interference sources; S4, inputting the first output waveforms of all groups of interference sources into a power amplification circuit to obtain a second output waveform of each group of first output waveforms with increased output power; S5, inputting all groups of second output waveforms into a plurality of coils respectively, and equivalently simulating magnetic field interferences with various characteristics inside the plurality of coils; S6. All coils are stacked in space to simulate the complex magnetic field interference environment in the power transmission and transformation scenario; S7. Expose the test product to a complex magnetic field interference environment, conduct performance test, and evaluate the operating performance of the test product under complex magnetic field interference.

2. The power transmission and transformation complex magnetic field interference equivalent test method according to claim 1 is characterized in that: 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 magnetic field interference, lightning magnetic field interference, short-circuit magnetic field interference and geomagnetic interference.

3. The power transmission and transformation complex magnetic field interference equivalent test method according to claim 2 is characterized in that: In S1, the basic characteristic parameters of the 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; The frequency domain characteristic parameters include the upper limit frequency, bandwidth and dominant frequency of the magnetic field interference.

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

5. The power transmission and transformation complex magnetic field interference equivalent test method according to claim 1 is characterized in that: In the above-mentioned S4, the second output waveform is a current waveform.

6. The power transmission and transformation complex magnetic field interference equivalent test method according to claim 1 is characterized in that: In S5, the coil types include but are not limited to solenoids, single-turn rectangular coils, single-turn circular coils and Helmholtz coils.

7. The power transmission and transformation complex magnetic field interference equivalent test method according to claim 1 is characterized in that: In S5, adjustable capacitors are connected in series and in parallel to the coil to change the impedance value and match it with the characteristic impedance of the transmission line.

8. The power transmission and transformation complex magnetic field interference equivalent test method according to claim 1 is characterized in that: In S6, all coils are overlapped in space, and the interfering magnetic fields from different sources are simulated to achieve vector superposition from different directions by changing the orientation of any coil.

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