Generation device and method of broadband disturbance signal

Abstract

The invention discloses a broadband disturbance signal generation device and method, and belongs to the technical field of power equipment, and the device comprises a power frequency voltage generation module, a high frequency voltage generation module, a sample module and a signal acquisition module. The power frequency voltage generation module is used for outputting voltage; the high-frequency voltage generation module is used for boosting the output voltage; the sample module is used for providing a sample and performing test operation; the signal acquisition module is used for measuring voltage. According to the invention, a disturbance signal with wider coverage frequency can be generated, and the test and research requirements of broadband and high-frequency harmonic characteristics of a modern converter cluster are effectively met.

Description

Technical Field

[0001] This invention belongs to the field of power equipment technology, specifically relating to a broadband disturbance signal generation device and method. Background Technology

[0002] Current research on harmonic generation devices mainly focuses on high-frequency, high-voltage generators. However, the voltage stress experienced by equipment in actual power grids is a superposition of power frequency and high-frequency harmonics. Current high-order harmonic generation devices cannot accurately reflect the actual operation of the power grid. Furthermore, harmonic disturbances from various converter clusters exhibit broadband and high-frequency characteristics, while current experimental platforms have relatively low superimposed harmonic frequencies and insufficient coverage of the harmonic frequency range. Therefore, a method and device for generating broadband disturbance signals are proposed. Summary of the Invention

[0003] To address the above problems, this invention proposes a device and method for generating broadband disturbance signals.

[0004] The technical solution of the present invention is: a broadband disturbance signal generating device includes a power frequency voltage generating module, a high frequency voltage generating module, a sample module and a signal acquisition module;

[0005] The power frequency voltage generation module is used to output voltage;

[0006] The high-frequency voltage generation module is used to boost the output voltage;

[0007] The sample module is used to provide test specimens for testing.

[0008] The signal acquisition module is used to measure voltage.

[0009] Furthermore, the power frequency voltage generation module includes an interconnected control console and a power frequency transformer;

[0010] The control console is a 20kVA power frequency test control console, and the power frequency transformer is a 10kVA single-phase oil-immersed step-up test transformer with a turns ratio of 1:1600.

[0011] Furthermore, the high-frequency voltage generation module includes a connected high-frequency harmonic source and a high-frequency transformer;

[0012] The high-frequency transformer and the power frequency transformer are connected; the high-frequency transformer is a single-phase dry-type self-cooling transformer.

[0013] Furthermore, the signal acquisition module mainly includes a high-voltage probe, a differential voltage probe, a signal acquisition card, and a PC terminal;

[0014] High-voltage probes are used to measure output voltage;

[0015] Differential voltage probes are used to measure input voltage;

[0016] The signal acquisition card is used to acquire the output voltage signals of the high-voltage probe and the differential voltage probe;

[0017] The PC is used to display and analyze the acquired voltage signals.

[0018] The beneficial effects of this invention are: this device can generate disturbance signals that simultaneously contain power frequency fundamental waves and broadband harmonics, more accurately reproduce the real voltage stress of power grid equipment under harmonic environment, and can generate disturbance signals covering a wider frequency range, effectively meeting the testing and research needs of broadband and high frequency harmonic characteristics of modern converter clusters.

[0019] Based on the above apparatus, the present invention also proposes a method for generating a broadband disturbance signal, comprising the following steps:

[0020] S1. Place the power frequency transformer under no-load conditions and determine the primary and secondary voltage components of the power frequency transformer.

[0021] S2. When the power frequency transformer is carrying a capacitive load, determine the ratio of the secondary voltage to the primary voltage under different loads.

[0022] S3. Determine the power frequency voltage component when the harmonic source output voltage frequency is at its maximum.

[0023] S4. Based on the primary and secondary voltage components of the power frequency transformer, the ratio of secondary voltage to primary voltage under different loads, and the power frequency voltage components, the sample of the sample module is subjected to load operation under the superposition of power frequency voltage and harmonic voltage to generate a wideband disturbance signal.

[0024] Furthermore, S1 includes the following sub-steps:

[0025] S11. Place the power frequency transformer under no-load conditions and input voltage to the power frequency transformer through the control console;

[0026] S12. Measure the voltage input at the instrument port on the primary side of the power frequency transformer using a differential voltage probe, and measure the output voltage on the secondary side of the power frequency transformer using a high voltage probe.

[0027] S13. Based on the voltage input at the primary side instrument port and the secondary side output voltage of the power frequency transformer, adjust the turns ratio of the power frequency transformer to determine the primary and secondary voltage components of the power frequency transformer.

[0028] Furthermore, S2 includes the following sub-steps:

[0029] S21. When the power frequency transformer is connected to a capacitive load, measure the turns ratio and calculate the voltage amplification factor by connecting test samples with different capacitance values ​​to the power frequency transformer.

[0030] S22. Based on the voltage amplification factor, the voltage input at the instrument port on the primary side of the power frequency transformer is measured by a differential voltage probe, and the output voltage on the secondary side of the power frequency transformer is measured by a high voltage probe to determine the ratio of the secondary voltage to the primary voltage under different loads.

[0031] The beneficial effects of this invention are: it can generate a wider frequency perturbation signal, effectively meeting the testing and research needs of the wideband and high-frequency harmonic characteristics of modern converter clusters. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of a device for generating broadband disturbance signals;

[0033] Figure 2 A flowchart illustrating the method for generating broadband disturbance signals;

[0034] Figure 3 The voltage waveform superimposed on the capacitor of the test sample. Detailed Implementation

[0035] The embodiments of the present invention will be further described below with reference to the accompanying drawings.

[0036] like Figure 1 As shown, the present invention provides a broadband disturbance signal generating device, including a power frequency voltage generating module, a high frequency voltage generating module, a sample module, and a signal acquisition module;

[0037] The power frequency voltage generation module is used to output voltage;

[0038] The high-frequency voltage generation module is used to boost the output voltage;

[0039] The sample module is used to provide test specimens for testing.

[0040] The signal acquisition module is used to measure voltage.

[0041] The power frequency high voltage is generated by stepping up the output voltage of the voltage regulating control console through the power frequency transformer, and the high frequency voltage is obtained by stepping up the high frequency harmonic source through the high frequency transformer. By connecting the secondary output of the power frequency transformer and the secondary output of the high frequency transformer in series, the power frequency voltage and the high frequency harmonic are superimposed on the test object, so as to realize the actual situation that the voltage borne by the power equipment in the power grid operation is the superposition of the power frequency and the high frequency harmonic.

[0042] The specific implementation method is as follows: The power frequency voltage generation module consists of two parts: a voltage regulation control console and a power frequency step-up transformer. The voltage regulation control console is a 20kVA power frequency test control console. This console can achieve continuous voltage adjustment from 0-250V by adjusting the knob. The voltage adjustment step size can be adjusted according to the test requirements, making it easy to operate. The console is also equipped with an overcurrent protection device. When the current in the system exceeds the predetermined maximum value, the current protection device will trip, which helps protect the safety of the test equipment. The power frequency step-up transformer is a 10kVA single-phase oil-immersed step-up test transformer with a transformation ratio of 1:1600. The core is made of high-quality cold-rolled grain-oriented silicon steel sheets, and the fastening method uses steel clamps. The high-voltage coil is a cylindrical multi-layer tower type, wound with high-quality polyester enameled wire and high withstand voltage insulation material, with high insulation and light weight. The low-voltage coil is external, and the instrument coil is an independent 100V winding.

[0043] The high-frequency harmonic voltage generation module consists of two parts: a high-frequency harmonic voltage source and a high-frequency step-up transformer. The high-frequency harmonic voltage source is a ZGX-15 programmable high-frequency harmonic source with a capacity of 5kW, capable of adjustable output from 0-150V, and supporting harmonic editing from 0.01Hz to 3000Hz. This power supply can also compensate for cable voltage drop by adjusting the output voltage, ensuring the voltage across the device under test equals the set voltage, thus achieving testing accuracy. The power supply features multiple protection systems including overcurrent protection, overvoltage protection, overpower protection, and undervoltage protection, and has a voltage ramp-up rate setting to ensure stable transformer output during operation. It also supports self-measurement of output voltage, current, and power for each phase. The high-frequency transformer is a single-phase dry-type self-cooled transformer with a U-shaped ferrite core, a turns ratio of 100:10000, a capacity of 2kVA, and a rated operating frequency of 3kHz.

[0044] The signal acquisition module mainly consists of four parts: a high-voltage probe, a differential voltage probe, a signal acquisition card, and a PC terminal. During the experiment, to acquire the secondary port voltage of the high-frequency transformer, the voltage probes used were all HIOKI 9322 differential voltage probes. These probes consist of two equal but oppositely polarized transistors. Based on differential amplification technology, they can be used to measure the voltage difference between two points in a circuit, while effectively suppressing common-mode noise. They are particularly suitable for high-frequency, high-precision measurement scenarios. This differential probe can acquire AC signals up to 1000V with a bandwidth of 0-10MHz.

[0045] In this embodiment of the invention, the power frequency voltage generation module includes a control console and a power frequency transformer connected to each other;

[0046] The control console is a 20kVA power frequency test control console, and the power frequency transformer is a 10kVA single-phase oil-immersed step-up test transformer with a turns ratio of 1:1600.

[0047] In this embodiment of the invention, the high-frequency voltage generation module includes a connected high-frequency harmonic source and a high-frequency transformer;

[0048] The high-frequency transformer and the power frequency transformer are connected; the high-frequency transformer is a single-phase dry-type self-cooling transformer.

[0049] In this embodiment of the invention, the signal acquisition module mainly includes a high-voltage probe, a differential voltage probe, a signal acquisition card, and a PC terminal;

[0050] High-voltage probes are used to measure output voltage;

[0051] Differential voltage probes are used to measure input voltage;

[0052] The signal acquisition card is used to acquire the output voltage signals of the high-voltage probe and the differential voltage probe;

[0053] The PC is used to display and analyze the acquired voltage signals.

[0054] Based on the above apparatus, the present invention also proposes a method for generating a broadband disturbance signal, such as... Figure 2 As shown, it includes the following steps:

[0055] S1. Place the power frequency transformer under no-load conditions and determine the primary and secondary voltage components of the power frequency transformer.

[0056] S2. When the power frequency transformer is carrying a capacitive load, determine the ratio of the secondary voltage to the primary voltage under different loads.

[0057] S3. Determine the power frequency voltage component when the harmonic source output voltage frequency is at its maximum.

[0058] S4. Based on the primary and secondary voltage components of the power frequency transformer, the ratio of secondary voltage to primary voltage under different loads, and the power frequency voltage components, the sample of the sample module is subjected to load operation under the superposition of power frequency voltage and harmonic voltage to generate a wideband disturbance signal.

[0059] First, the power frequency transformer is placed under no-load conditions. The pressure control console is adjusted to supply a certain voltage input to the power frequency transformer. The voltage input at the instrument port on the primary side of the power frequency transformer is measured by a differential probe, and the output voltage on the secondary side of the power frequency transformer is measured by a high-voltage probe. The turns ratio of the power frequency transformer is corrected, and the voltage components of the primary and secondary sides of the power frequency transformer are analyzed to provide a reference for the subsequent superposition of power frequency voltage and harmonic voltage.

[0060] When a power frequency transformer is connected to a capacitive load, the capacitive current leads the voltage, which triggers a capacitive rise effect due to the interaction between the secondary leakage inductance and the capacitor, resulting in a significant increase in output voltage. To ensure equipment safety during testing and to quantify this phenomenon, the turns ratio of the power frequency transformer was measured by individually connecting test samples with different capacitance values, and the voltage amplification factor was calculated. The capacitance values ​​of the test samples were changed to 0.6nF, 1nF, 2nF, and 5nF. The voltage input at the instrument port on the primary side of the power frequency transformer was measured using a differential probe, and the secondary output voltage was measured using a high-voltage probe. The ratio of the secondary voltage to the primary voltage under different loads was recorded.

[0061] The core of a power frequency transformer is typically designed to operate at power frequency. Under power frequency voltage, the core's hysteresis characteristics and the material's permeability function effectively. However, when high-frequency harmonics are present in the system, the rapid magnetic field changes caused by these harmonics can lead to local saturation of leakage flux, reducing the transformer core's response to the magnetic field. The higher the frequency of the high-frequency voltage, the greater the impact. The presence of high-frequency current in the windings, due to the skin effect, increases the equivalent resistance of the windings, causing distortion of the excitation current waveform and potentially saturating the transformer core. Therefore, this study investigates whether the magnitude of the output harmonic voltage affects the performance of the power frequency transformer in this circuit, assuming the harmonic source output voltage frequency is at its maximum. A 1nF capacitor was used as the test capacitor. The output voltage frequency of the harmonic power supply was set to 3000Hz, with voltage values ​​of 10V, 20V, 30V, and 40V. The voltage was boosted by a high-frequency transformer, allowing the harmonic voltage and current to flow into the system. The input voltage of the power frequency transformer was adjusted by rotating the voltage regulating dial to 2.25V and 3V respectively. A high-voltage probe was used to measure the voltage on the test capacitor, and its power frequency voltage component was analyzed. The experiment revealed that as the harmonic source output increased, the power frequency voltage component on the test capacitor did not change with the increase of the harmonic voltage. Furthermore, the voltage value on the test capacitor at this point was equal to that under the condition of no output after the high-frequency source was connected to the system. Within this range, the high-frequency harmonic voltage did not affect the operating performance of the power frequency transformer.

[0062] After the above tests, a load test was conducted under the superposition of power frequency voltage and harmonic voltage to verify whether this test circuit could achieve the superposition of power frequency voltage and harmonic voltage on the test object. A 1nF capacitor was selected as the test object capacitor. The output of the power frequency transformer control console and the harmonic source output were adjusted. The primary input voltage of the two transformers was measured using a differential probe, and the voltage on the test object capacitor was measured using a high voltage probe. The following is the measured waveform of the superposition of 5720V power frequency voltage and 627V 3000Hz harmonic voltage on the 1nF test object capacitor during the actual experiment. Figure 3 As shown, this test circuit can superimpose power frequency voltage and harmonic voltage onto the test sample. This device can effectively generate broadband disturbance signals.

[0063] In this embodiment of the invention, S1 includes the following sub-steps:

[0064] S11. Place the power frequency transformer under no-load conditions and input voltage to the power frequency transformer through the control console;

[0065] S12. Measure the voltage input at the instrument port on the primary side of the power frequency transformer using a differential voltage probe, and measure the output voltage on the secondary side of the power frequency transformer using a high voltage probe.

[0066] S13. Based on the voltage input at the primary side instrument port and the secondary side output voltage of the power frequency transformer, adjust the turns ratio of the power frequency transformer to determine the primary and secondary voltage components of the power frequency transformer.

[0067] In this embodiment of the invention, S2 includes the following sub-steps:

[0068] S21. When the power frequency transformer is connected to a capacitive load, measure the turns ratio and calculate the voltage amplification factor by connecting test samples with different capacitance values ​​to the power frequency transformer.

[0069] S22. Based on the voltage amplification factor, the voltage input at the instrument port on the primary side of the power frequency transformer is measured by a differential voltage probe, and the output voltage on the secondary side of the power frequency transformer is measured by a high voltage probe to determine the ratio of the secondary voltage to the primary voltage under different loads.

[0070] Those skilled in the art will recognize that the embodiments described herein are intended to help the reader understand the principles of the invention, and should be understood that the scope of protection of the invention is not limited to such specific statements and embodiments. Those skilled in the art can make various other specific modifications and combinations based on the technical teachings disclosed in this invention without departing from the spirit of the invention, and these modifications and combinations are still within the scope of protection of this invention.

Claims

1. A device for generating a broadband disturbance signal, characterized in that, The power frequency voltage generating module, the high frequency voltage generating module, the sample module and the signal acquisition module are included. The power frequency voltage generating module is used for outputting voltage. The high frequency voltage generating module is used for boosting the output voltage. The sample module is used for providing samples and performing test operations. The signal acquisition module is used for measuring voltage.

2. The broadband perturbation signal generating device of claim 1, wherein The power frequency voltage generating module includes a control console and a power frequency transformer connected with each other. The control console is a power frequency test control console with a capacity of 20 kVA, and the power frequency transformer is a single-phase oil-immersed step-up test transformer with a capacity of 10 kVA and a transformation ratio of 1:1600.

3. The broadband perturbation signal generating device of claim 1, wherein The high frequency voltage generating module includes a high frequency harmonic source and a high frequency transformer connected with each other. The high frequency transformer is connected with the power frequency transformer, and is a single-phase dry-type self-cooling transformer.

4. The broadband perturbation signal generating device of claim 1, wherein The signal acquisition module mainly includes a high voltage probe, a differential voltage probe, a signal acquisition card and a PC end. The high voltage probe is used for measuring output voltage. The differential voltage probe is used for measuring input voltage. The signal acquisition card is used for acquiring output voltage signals of the high voltage probe and the differential voltage probe. The PC end is used for displaying and analyzing the acquired voltage signals.

5. A method for generating a broadband perturbation signal, the method comprising: The method includes the following steps: S1, placing the power frequency transformer in an unloaded state, and determining a primary voltage component and a secondary voltage component of the power frequency transformer; S2, when the power frequency transformer is loaded with a capacitive load, determining a ratio of the secondary voltage to the primary voltage under different loads; S3, when the harmonic source outputs voltage at a maximum frequency, determining a power frequency voltage component; S4, based on the primary voltage component and the secondary voltage component of the power frequency transformer, the ratio of the secondary voltage to the primary voltage under different loads and the power frequency voltage component, performing a load operation on the samples of the sample module under the superposition of the power frequency voltage and the harmonic voltage, and completing generation of a wideband disturbance signal.

6. The method of claim 5, wherein the broadband perturbation signal is generated by: The S1 includes the following sub-steps: S11, placing the power frequency transformer in an unloaded state, and inputting voltage to the power frequency transformer through the control console; S12, measuring the voltage input at the instrument port on the primary side of the power frequency transformer through the differential voltage probe, and measuring the output voltage of the power frequency transformer on the secondary side through the high voltage probe; S13, based on the voltage input at the instrument port on the primary side of the power frequency transformer and the output voltage on the secondary side, adjusting the transformation ratio of the power frequency transformer, and determining the primary voltage component and the secondary voltage component of the power frequency transformer.

7. The method of claim 5, wherein the broadband perturbation signal is generated by: The S2 includes the following sub-steps: S21, when the power frequency transformer is loaded with a capacitive load, connecting different capacity samples to the power frequency transformer, performing transformation ratio measurement, and calculating voltage amplification; S22, based on the voltage amplification, measuring the voltage input at the instrument port on the primary side of the power frequency transformer through the differential voltage probe, measuring the output voltage of the power frequency transformer on the secondary side through the high voltage probe, and determining the ratio of the secondary voltage to the primary voltage under different loads.

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