Power grid transient peak monitoring device based on high-voltage differential filtering technology

Abstract

The invention belongs to the technical field of electronic testing, and particularly relates to a power grid transient peak monitoring device based on a high-voltage differential filtering technology. The device comprises an active high-voltage differential peak sensor which comprises a high-voltage differential conversion module and a filtering module; the high-voltage differential conversion module is used for extracting, converting and outputting a power grid radio frequency transient peak voltage signal; the filtering module is used for filtering a power grid low-frequency signal of the power grid radio frequency transient peak voltage signal and outputting the power grid low-frequency signal; the power grid transient peak monitoring module is used for acquiring the analog voltage signal converted and output by the peak sensor in real time, performing real-time compensation on a sensor coefficient to obtain an actual power grid transient peak waveform and peak original data, and performing real-time capture and acquisition on the power grid transient peak signal; wherein the real-time compensation of the sensor coefficient comprises linear spectrum coefficient calibration compensation and time domain coefficient compensation based on frequency domain distribution.

Description

Technical Field

[0001] The invention belongs to the technical field of electronic testing, and in particular relates to a power grid transient spike monitoring device based on high-voltage differential filtering technology. Background Art

[0002] With the development of science and technology, new technologies and products are widely used on ships, aircraft and other platforms, which greatly improves the technical level of equipment, but also brings some electromagnetic compatibility problems caused by transient interference of power grid. Nowadays, on ships, aircraft and other platforms, there are dense cables, a large number of high-power power generation and substation equipment, and a substantial increase in generator power. The overall electromagnetic environment of the power grid is complicated, which makes the sensitive equipment on site particularly susceptible to transient electromagnetic interference on the power grid, especially in the full-electric mode. The interference problem of high voltage and high current will be very prominent. According to previous engineering experience, most high-power equipment (including generators, pumps, fans, etc.) will conduct transient spike emission interference on the power grid during the start-stop process, thereby causing certain transient interference effects on the power supply of sensitive equipment on site.

[0003] Since the transient spike interference of power grid conduction is mostly non-periodic or random interference, and the rise time of this transient spike signal is short (us / ns), the start-up and shutdown process of high-power equipment is fast, and the peak voltage amplitude is large, the traditional external filter plus standard differential probe connected to the oscilloscope needs to be manually operated to collect the spike signal. It is difficult to achieve long-term capture and monitoring, and when there are many measuring points, it is difficult to achieve multi-point distributed monitoring under transient conditions. At the same time, the traditional external filter plus standard differential probe has high requirements for on-site testing. If an external passive high-pass filter is used, it needs to be floated and the oscilloscope must also be isolated for power supply. There are certain safety hazards in long-term access to the power grid for testing or real-time monitoring. Therefore, how to capture and measure the transient spike signal of the power grid in real time without damaging the power grid and ensuring safety is a difficult problem.

[0004] In addition, in the power line spike conduction sensitivity test items (CS106) of standards such as GJB151A / 151B, most of the current testing units monitor the applied standard interference signal at the output end of the spike signal generator, but fail to monitor the applied standard spike interference signal at the load end as required by the standard. This is because the signal monitored at the load end is a superimposed signal formed by the standard spike interference signal and the power grid power frequency voltage signal. The existing instrument configuration cannot conveniently extract and measure the spike signal. Therefore, how to more conveniently extract and measure the standard spike signal at the load end in the spike injection sensitivity test item is also a problem that needs to be solved urgently. Summary of the invention

[0005] In view of the defects of the existing technology and technical needs, in order to solve the above-mentioned technical problems, the present invention provides a power grid transient spike monitoring device based on high-voltage differential filtering technology, the purpose of which is to be able to capture and monitor the transient spike signal of the power grid in real time without damaging the power grid and ensuring safety, and at the same time, it can more conveniently extract and measure the standard spike signal at the load end in the spike injection sensitivity test project.

[0006] The technical solution for implementing the present invention is as follows:

[0007] A power grid transient peak monitoring device based on high-voltage differential filtering technology, mainly composed of an active high-voltage differential peak sensor, a power grid transient peak monitoring module and a power supply module;

[0008] The active high-voltage differential peak sensor includes a high-voltage differential conversion module and a filtering module; the high-voltage differential conversion module is used to extract and convert the output grid radio frequency transient peak voltage signal; the filtering module is used to filter out the grid low-frequency signal of the grid radio frequency transient peak voltage signal and output it;

[0009] The grid transient spike monitoring module is used to collect the analog voltage signal converted and output by the spike sensor in real time, and obtain the actual grid transient spike waveform and spike raw data by performing real-time compensation on the sensor coefficient, and to capture and collect the grid transient spike signal in real time; wherein the real-time compensation on the sensor coefficient includes linear spectrum coefficient calibration compensation and time domain coefficient compensation based on frequency domain distribution;

[0010] The linear spectrum coefficient calibration compensation is as follows: the time domain data of the grid radio frequency transient spike voltage signal is Fourier transformed to obtain the grid transient spike spectrum data, and then the frequency domain attenuation of the active high voltage differential spike sensor, i.e., the insertion loss, is automatically compensated online;

[0011] The compensation of the time domain coefficient based on the frequency domain distribution is as follows: the time domain data of the grid radio frequency transient spike voltage signal is subjected to Fourier transformation to obtain the grid transient spike spectrum data, and the spectrum data is sorted according to the amplitude, the peak frequency domain distribution is statistically analyzed, the frequency component proportion is weighted and scored, the sensor frequency coefficients corresponding to the top N frequency components are extracted, the time domain coefficients are calculated, and linear time domain compensation is performed based on the time domain coefficients;

[0012] The power supply module is used to provide power to the peak sensor and the peak monitoring module.

[0013] Furthermore, the monitoring parameters of the present invention include: voltage peak, trigger level, pulse width, frequency, and rise / fall time.

[0014] Furthermore, the present invention calculates the mean value of the N time domain coefficients, and uses the mean value to perform linear time domain compensation on the collected peak time domain data.

[0015] Furthermore, the high-voltage differential conversion module of the present invention includes a differential operational amplifier circuit, and utilizes a front-end optical coupling isolation circuit to safely isolate the high voltage, while attenuating the high-voltage signal in the power grid at a fixed ratio within a certain frequency range.

[0016] Furthermore, the insertion loss of the filter module of the present invention is close to 0 within the high-pass frequency range, and the cut-off frequency is adjustable.

[0017] Furthermore, the device of the present invention also includes a metal shielding box for packaging the high-voltage differential conversion module.

[0018] Furthermore, the present invention adaptively captures and collects grid transient spike signals in real time based on a multi-type triggering algorithm based on grid transient spike adaptation, including amplitude triggering, frequency triggering or rising edge / falling edge triggering, and prioritizes the triggering methods of the triggering success rate data of external grid transient spikes through various triggering methods, thereby realizing automatic selection of actual grid transient spike signals.

[0019] Furthermore, the peak adaptive multi-class triggering algorithm of the present invention also includes online adjustment of trigger conditions. When amplitude triggering is performed, when the grid transient peak monitoring module starts to collect, real-time capture and monitoring begins according to the initial trigger level value. If the peak waveform is not captured, the trigger level amplitude is automatically and adaptively lowered. By comparing the real-time peak amplitude with the focus amplitude, the system will automatically and adaptively increase the trigger level amplitude. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0021] Figure 1 It is a schematic diagram of the device composition of the present invention;

[0022] Figure 2 This is a schematic diagram of the peak conduction sensitivity test in the present invention;

[0023] Figure 3 This is a schematic diagram of the peak conduction sensitivity test system verification in the present invention;

[0024] Figure 4 This is a schematic diagram of the power grid transient peak monitoring function in the present invention. DETAILED DESCRIPTION

[0025] The embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0026] It should be noted that the following embodiments and features in the embodiments may be combined with each other in the absence of conflict; and, based on the embodiments in the present disclosure, all other embodiments obtained by ordinary technicians in the field without making any creative work are within the scope of protection of the present disclosure.

[0027] It should be noted that various aspects of the embodiments within the scope of the appended claims are described below. It should be apparent that the aspects described herein may be embodied in a wide variety of forms, and any specific structure and / or function described herein is merely illustrative. Based on the present disclosure, it should be understood by those skilled in the art that an aspect described herein may be implemented independently of any other aspect, and two or more of these aspects may be combined in various ways. For example, any number of aspects described herein may be used to implement the device and / or practice the method. In addition, other structures and / or functionalities other than one or more of the aspects described herein may be used to implement this device and / or practice this method.

[0028] The present invention provides a power grid transient spike monitoring device based on high-voltage differential filtering technology, which can capture and monitor power grid transient spike signals in real time without damaging the power grid and ensuring safety, and can also more conveniently extract and measure standard spike signals at the load end in a spike injection sensitivity test project.

[0029] By applying the present invention, the load-end standard peak voltage of the power line peak conduction sensitivity test item (CS106) in the GJB151A / 151B and other standards can be extracted and measured, and at the same time, the transient peak conduction emission on the power grid can be monitored in real time under the start-stop working conditions of the external high-voltage and high-power equipment, thereby realizing the real-time online monitoring and measurement of the transient peak voltage of the power grid in the electromagnetic environment of the external high-voltage and high-current power grid.

[0030] The present invention will be further described below in conjunction with the accompanying drawings and examples.

[0031] The present application embodiment is a power grid transient spike monitoring device based on high-voltage differential filtering technology, which is mainly composed of an active high-voltage differential spike sensor, a power grid transient spike monitoring module and a power supply module. Figure 1 shown.

[0032] (1) Active high voltage differential spike sensor

[0033] The active high-voltage differential spike sensor mainly includes a high-voltage differential conversion module and a filtering module, among which:

[0034] The high-voltage differential conversion module is based on a high-precision differential operational amplifier circuit. It uses a front-end optical coupler isolation circuit to safely isolate the high voltage and can attenuate the high-voltage signal in the power grid at a fixed ratio within a certain frequency range. The measurement bandwidth can reach 60MHz and the insertion loss flatness is ±6dB.

[0035] The filter module is mainly based on a high-pass filter circuit, which filters out low-frequency signals from the power grid (including industrial frequency high-voltage signals) and retains the power grid's RF transient spike signals. The insertion loss is close to 0 within the high-pass frequency range. At the same time, the filter module can adjust the cutoff frequency to achieve large dynamic range and wide-band transient spike testing of the power grid.

[0036] Since the high-voltage differential circuit module has a high gain and is easily affected by external electromagnetic fields, it can be packaged in a metal shielding box. At the same time, the high-voltage differential module and filter module need to be packaged using an integrated process to avoid safety hazards caused by installation process problems such as filter grounding.

[0037] (2) Grid transient peak monitoring module

[0038] The grid transient spike monitoring module is mainly used to collect the analog voltage signal converted by the spike sensor in real time. After processing and analysis by adaptive multi-type trigger modes and automatic online compensation algorithm of sensor coefficients, the actual grid transient spike waveform and spike raw data are obtained, and the spike real-time voltage peak value, trigger level, pulse width, frequency, rise / fall time and other spike monitoring parameters are extracted, and the parameters are saved and uploaded in real time.

[0039] a) Adaptive multi-class triggering algorithm for power grid transient spikes

[0040] The adaptive multi-class trigger algorithm for power grid transient spikes refers to the use of multiple triggering methods such as amplitude triggering, frequency triggering or rising edge / falling edge triggering to adaptively capture and collect power grid transient spike signals in real time. Among them, multiple triggering methods can be adaptively selected according to the characteristics of power grid transient spike signals, and the triggering methods are prioritized according to the triggering success rate data of external power grid transient spikes in various previous triggering methods, so as to realize automatic selection of actual power grid transient spike signals. At the same time, the adaptive multi-class trigger algorithm for spikes can also automatically adjust the trigger conditions online. Taking amplitude triggering as an example, when the power grid transient spike monitoring module starts to collect, it starts real-time capture and monitoring according to the initial trigger level value. If the spike waveform is not captured (or other automatic adjustment conditions are triggered, such as exceeding the waiting time, the initial trigger level is too large, etc.), the system will automatically and adaptively reduce the trigger level amplitude, and the range of reduction can be customized; if the system automatically compares the real-time spike amplitude with the attention amplitude, and finds that there are too many spike waveforms captured in real time that are far lower than the attention amplitude, the system will automatically and adaptively increase the trigger level amplitude, and the range of increase can also be customized. In this way, for amplitude triggering, the function of automatically scanning the trigger level and capturing the grid peak in real time is realized.

[0041] b) Automatic online compensation algorithm for peak sensor coefficients

[0042] i) Linear spectrum coefficient calibration compensation algorithm

[0043] The linear spectrum coefficient calibration and compensation algorithm obtains the grid transient peak spectrum data by Fourier transform (FFT) of the spike time domain data captured in real time, and then automatically compensates the frequency domain attenuation (insertion loss) of the active high-voltage differential spike sensor online, so that the actual maximum amplitude of the transient spike can be calculated in real time.

[0044] ii) Time domain coefficient compensation algorithm based on frequency domain distribution

[0045] The time domain coefficient compensation algorithm based on frequency domain distribution is to obtain the power grid transient peak spectrum data by Fourier transform (FFT) of the peak time domain data captured in real time, sort the spectrum data according to the amplitude, count the peak frequency domain distribution, weight the frequency component proportion, extract the top N frequency components, calculate the frequency coefficients of the top N corresponding frequency sensors, and calculate the time domain coefficient. The linear time domain compensation is performed on the collected peak time domain data by averaging the N time domain coefficients, so that the actual power grid transient peak data can be analyzed in real time.

[0046] (3) Power supply module

[0047] The power supply module is mainly used to provide power to the spike sensor and the spike monitoring module. Since the high-voltage differential circuit module has high precision, the power quality provided by the power supply module has a great influence on the precision of the operational amplifier. Therefore, it is necessary to design a power supply circuit with small ripple and high precision for power supply, or use high-quality batteries or cells for power supply.

[0048] The present application embodiment utilizes the power line spike conduction sensitivity test system composed of the spike monitoring device

[0049] Figure 2 This is a configuration diagram of the power line spike conduction sensitivity test system composed of a spike monitoring device. Figure 2 It can be seen that by connecting the spike monitoring device to both ends of the EUT / load, the actual unfiltered spike waveform and filtered spike waveform at both ends of the EUT can be monitored and extracted in real time during the test, and the filtered spike data can be saved and uploaded. The principle and method of the power line spike conduction sensitivity test based on the spike monitoring device are as follows:

[0050] a) Verification

[0051] like Figure 3 As shown, adjust the spike signal generator to the minimum output, use an oscilloscope to monitor the voltage waveform of the 5Ω non-inductive resistor, and increase the signal level until the oscilloscope voltage reaches the limit value V pkL (GJB151A / 151B and other standards specify voltage limits), confirm the output waveform and pulse width, record the peak signal generator setting value (calibration value), the peak voltage V read by the analog voltage output channel connected to the oscilloscope after the peak monitoring device is filtered pk1 The peak value V is obtained by processing and analyzing the peak value V pk2 , measured value V pk1 and V pk2 Should be at V pkL The error range is ±10%.

[0052] b) EUT test

[0053] like Figure 2As shown, adjust the output of the spike signal generator to the minimum, increase the signal level, until the voltage limit required by the standard or the calibration value of the spike signal generator in a) is reached on the power line. This level is the required signal level. The level can be measured by connecting the analog voltage output channel of the spike monitoring device after filtering to the oscilloscope for reading, or it can be directly obtained through the spike data saved or uploaded by the spike monitoring device. At the same time, while keeping the signal level not lower than the required signal level, set the spike signal repetition frequency (5Hz~10Hz) and add it to the EUT power input line terminal respectively. For AC power supply, the spike signal should be synchronized with the power supply frequency and adjusted at every 90° phase, each time for not less than 5 minutes. In addition, it is also required to adjust the phase of the spike signal so that it appears within the range of 0°~360° of the power supply fundamental wave. The phase adjustment can be completed by connecting the analog voltage output channel of the spike monitoring device before filtering to the oscilloscope for monitoring. Since the spike monitoring device can more conveniently monitor the spike signal level and phase at the EUT end, the EUT performance degradation status can be monitored more intuitively, thereby achieving the purpose of power line spike conduction sensitivity testing.

[0054] Monitoring function principle of the power grid transient spike monitoring device based on high voltage differential filtering technology in the embodiment of the present application

[0055] like Figure 4 As shown, the monitoring function of the power grid transient spike monitoring device based on high-voltage differential filtering technology refers to connecting the power grid transient spike monitoring device based on high-voltage differential filtering technology in parallel to the external power grid distribution box, and after the power line input signal is processed by the high-voltage differential filtering circuit, the power grid transient spike signal is automatically captured and collected in real time by using multiple triggering methods such as amplitude triggering, frequency triggering or rising edge / falling edge triggering, and after comprehensive analysis, the peak real-time voltage peak value, trigger level, pulse width, frequency, rise / fall time and other data can be obtained, and the data can be saved and uploaded in real time. At the same time, the power grid spike conduction emission signal can be monitored, analyzed and recorded online for a long time without manual intervention, especially under the start-stop condition of high-voltage and high-power equipment in the external field, the power grid transient spike conduction interference signal can be captured online in real time, so that the real-time online monitoring and measurement of the power grid transient spike voltage can be realized in the electromagnetic environment of the external high-voltage and high-current power grid. Therefore, a grid transient spike monitoring device based on high-voltage differential filtering technology is used to monitor grid spike signals. This can not only grasp the grid spike status at the project site in real time, but also obtain auxiliary troubleshooting suggestions when spike interference occurs. It can also trace back grid spike data after spike interference occurs to locate faults, thereby greatly improving the efficiency of electromagnetic interference troubleshooting and ensuring the progress of the project.

[0056] By applying the present invention, the load-end standard peak voltage of the power line peak conduction sensitivity test item (CS106) in the GJB151A / 151B and other standards can be extracted and measured, and at the same time, the transient peak conduction emission on the power grid can be monitored in real time under the start-stop working conditions of the external high-voltage and high-power equipment, thereby realizing the real-time online monitoring and measurement of the transient peak voltage of the power grid in the electromagnetic environment of the external high-voltage and high-current power grid.

[0057] According to the disclosure of the present invention, a person skilled in the art can use other similar methods to design and implement a power grid transient peak monitoring device based on high voltage differential filtering technology, and is not limited to Figure 1 to Figure 4 The method shown.

[0058] Specifically, the present invention has the following characteristics:

[0059] (1) High test accuracy

[0060] The peak value accuracy of the power grid transient spike monitoring device tested based on high-voltage differential filtering technology is better than ±10%.

[0061] (2) The voltage test has a large dynamic range and a high withstand voltage level

[0062] The grid transient spike monitoring device can monitor spike signals with a voltage peak of at least 600V, and the maximum withstand voltage can reach 1000V.

[0063] (3) Good safety and high isolation

[0064] The grid transient peak monitoring device has a filtering function, and the front end of the differential circuit is equipped with an optical coupler isolation, which can effectively isolate the power frequency high voltage signal in the complex external grid. At the same time, the device packages the high voltage differential and filtering integrated process to avoid safety hazards caused by installation process problems such as filter grounding.

[0065] (4) Large test bandwidth and good flatness

[0066] The test frequency range of the power grid transient spike monitoring device is 10kHz~30MHz, and the insertion loss flatness is ±6dB.

[0067] (5) Good practicality and high efficiency

[0068] The device can perform parallel access testing without affecting the on-site power grid installation and layout. At the same time, there is no need to connect instruments and equipment for manual operation testing. The device can automatically trigger and capture transient spikes in real time to achieve distributed monitoring of multiple measuring points. The test is efficient, easy to implement, and practical.

[0069] (6) Wide applicability and strong real-time performance

[0070] In addition to meeting the peak conduction emission test requirements of ships, aircraft and other platforms, it can also be used for peak tests on other platforms and has a wide range of applicability. This device integrates high-voltage differential, filtering and real-time monitoring, and can perform long-term multi-point distributed monitoring of power grid peak conduction emission signals without human intervention, and can capture, save and upload them in real time.

[0071] It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A power grid transient spike monitoring device based on high voltage differential filtering technology, characterized in that: It is mainly composed of active high-voltage differential spike sensor, grid transient spike monitoring module and power supply module; The active high-voltage differential peak sensor includes a high-voltage differential conversion module and a filtering module; the high-voltage differential conversion module is used to extract and convert the output grid radio frequency transient peak voltage signal; the filtering module is used to filter out the grid low-frequency signal of the grid radio frequency transient peak voltage signal and output it; The grid transient spike monitoring module is used to collect the analog voltage signal converted and output by the spike sensor in real time, and obtain the actual grid transient spike waveform and spike raw data by performing real-time compensation on the sensor coefficient, and to capture, collect and monitor the grid transient spike signal parameters in real time; wherein the real-time compensation on the sensor coefficient includes linear spectrum coefficient calibration compensation and time domain coefficient compensation based on frequency domain distribution; The linear spectrum coefficient calibration compensation is as follows: the time domain data of the grid radio frequency transient spike voltage signal is Fourier transformed to obtain the grid transient spike spectrum data, and then the frequency domain attenuation of the active high voltage differential spike sensor, i.e., the insertion loss, is automatically compensated online; The compensation of the time domain coefficient based on the frequency domain distribution is as follows: the time domain data of the grid radio frequency transient spike voltage signal is subjected to Fourier transformation to obtain the grid transient spike spectrum data, and the spectrum data is sorted according to the amplitude, the peak frequency domain distribution is statistically analyzed, the frequency component proportion is weighted and scored, the sensor frequency coefficients corresponding to the top N frequency components are extracted, the time domain coefficients are calculated, and linear time domain compensation is performed based on the time domain coefficients; The power supply module is used to provide power to the peak sensor and the peak monitoring module.

2. The power grid transient peak monitoring device based on high voltage differential filtering technology according to claim 1 is characterized in that: The monitoring parameters include: voltage peak, trigger level, pulse width, frequency, and rise / fall time.

3. The power grid transient peak monitoring device based on high voltage differential filtering technology according to claim 1 is characterized in that: The mean value of the N time domain coefficients is calculated, and the linear time domain compensation is performed on the collected peak time domain data using the mean value.

4. The power grid transient spike monitoring device based on high voltage differential filtering technology according to claim 1 is characterized in that: The high-voltage differential conversion module includes a differential operational amplifier circuit, and utilizes a front-end optical coupling isolation circuit to safely isolate the high voltage, while attenuating the high-voltage signal in the power grid at a fixed ratio within a certain frequency range.

5. The power grid transient spike monitoring device based on high voltage differential filtering technology according to claim 1 is characterized in that: The insertion loss of the filter module is close to 0 in the high-pass frequency range, and the cut-off frequency is adjustable.

6. The power grid transient spike monitoring device based on high voltage differential filtering technology according to claim 1 is characterized in that: The device also includes a metal shielding box for packaging the high-voltage differential conversion module.

7. The power grid transient spike monitoring device based on high voltage differential filtering technology according to claim 1 is characterized in that: Based on the adaptive multi-type trigger algorithm of power grid transient spikes, the transient spike signals of the power grid are adaptively captured and collected in real time, including amplitude triggering, frequency triggering or rising edge / falling edge triggering. The triggering success rate data of the external field power grid transient spikes are prioritized through various triggering methods to realize automatic selection of the actual power grid transient spike signals.

8. The power grid transient peak monitoring device based on high voltage differential filtering technology according to claim 7 is characterized in that: The spike adaptive multi-class trigger algorithm also includes online adjustment of trigger conditions. When amplitude triggering is performed, the grid transient spike monitoring module starts collecting data and begins real-time capture and monitoring based on the initial trigger level value. If the spike waveform is not captured, the trigger level amplitude is automatically and adaptively lowered. By comparing the real-time peak amplitude with the focus amplitude, the system will automatically and adaptively increase the trigger level amplitude.

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