Discharge spectrum reproducing system

Abstract

The invention discloses a discharge map reproduction system, which comprises a control computer, a D / A conversion unit and a coupling tool, and is characterized in that the control computer converts a map in a typical partial discharge map library into an editable digital signal, the D / A conversion unit converts the signal into an analog signal, and the analog signal is output to the coupling tool to construct a typical test environment; and a corresponding programmable control typical partial discharge signal simulation environment is generated. The invention belongs to the technical field of discharge simulation reproduction, and aims to solve the problems that partial discharge defect simulation in the prior art is less, the technology has a blank, and partial discharge pulse and time sequence are difficult to reproduce accurately. The technical effects are that simulation reproduction of partial discharge signals is realized, workers can know the discharge condition, huge economic loss is avoided, and the vacancy of partial discharge reproduction technology is filled.

Description

Technical Field

[0001] The invention relates to the technical field of discharge simulation reproduction, and in particular to a discharge spectrum reproduction system. Background Art

[0002] Partial discharge is like a "tumor" in power equipment. If it is not discovered in advance, it will lead to insulation aging and eventually cause equipment collapse and power grid paralysis, causing huge economic losses and having a huge impact on people's living standards.

[0003] In the existing physical transformer partial discharge simulation technology, the simulation focus is mainly on the transformer winding. There are many methods for discharge simulation on the winding, but there are few simulations on partial discharge defects, and it is difficult to simulate and reproduce the partial discharge signal, which makes it difficult for the staff to understand the discharge situation. At the same time, there is a gap in this part of the technology. In addition, it is difficult to accurately reproduce the partial discharge pulse and timing. Summary of the invention

[0004] To this end, the present invention provides a discharge spectrum reproduction system to solve the above-mentioned problems in the prior art.

[0005] In order to achieve the above object, the present invention provides the following technical solutions:

[0006] According to a first aspect of the present invention, a discharge spectrum reproduction system comprises a control computer, a D / A conversion unit and a coupling tool, wherein the control computer converts the spectrum in the typical partial discharge spectrum library into an editable digital signal, and the D / A conversion unit converts the signal into an analog signal, which is output to the coupling tool to construct a typical test environment, and generate a corresponding programmable control typical partial discharge signal simulation environment;

[0007] The D / A conversion unit includes a storage module, a sequence generator module, a clock generator module, a digital-to-analog converter module, a low-pass filter module and an output amplifier module; specifically:

[0008] The memory module is used to load the digital representation of the waveform into the memory of the arbitrary waveform generator through the LabView application software. The clock frequency of the memory is 5 GHz. The depth of the memory indicates the length of the signal playback time. The memory size is 1.5GSa. Under the extreme output condition of 2.4k~500M sampling points per pulse, pulses can be continuously output.

[0009] The sequencer module is used to arrange the waveform into multiple segments to create the required waveform, solving the limitation of memory depth. The memory sorting only stores the key waveform parts, and the sequencer only records the waveform jumps but not the idle time, and keeps synchronization with the trigger signal generator that supports the waveform.

[0010] a clock generator module that controls the DAC module and the sequencer, thereby controlling the timing of the waveform; a memory controller that tracks waveform events in the memory and outputs them to the DAC module in the correct order; and a memory controller that stores repeated units in a loop so that they are listed only once in the waveform memory, thereby saving storage space;

[0011] The digital-to-analog converter module is used to convert the digital voltage value into an analog voltage. The number of bits of the digital-to-analog converter module will affect the vertical resolution of the memory. The higher the number of bits, the higher the vertical resolution and the more detailed the output waveform. The digital-to-analog converter module uses interpolation to achieve a higher update rate than the waveform memory. The number of bits of the memory and the digital-to-analog converter module is more than 12 bits, and the amplitude output range is 0.35 to 0.7V. Under the condition of the output in the extreme amplitude range, the output amplitude resolution is 2mV, which meets the requirements of partial discharge amplitude sequence simulation;

[0012] The low-pass filter module is used to filter the voltage steps output by the digital-to-analog converter module, which contain a large number of harmonic components, to obtain a smooth sinusoidal analog waveform;

[0013] The amplifier module is used to receive the signal after passing through the filter, and the amplifier module controls the gain and bias. According to the requirements of the partial discharge amplitude sequence simulation, the output gain and bias can be flexibly adjusted, and the distortion-free output with a high dynamic range can be ensured to ensure the linearity of the signal amplitude restoration.

[0014] Furthermore, the technical parameters of the storage device meet the signal simulation requirements of partial discharge.

[0015] Furthermore, the D / A conversion unit also includes a trigger, the trigger input is used to communicate information between the memory and the external device, and the trigger information changes the operation of the sequence generator, thereby allowing the selected waveform to enter the digital-to-analog converter module.

[0016] Furthermore, it also includes the simulation of the partial discharge single pulse waveform, selecting a double exponential pulse waveform, and constraining conditions in terms of pulse rising edge, pulse decay time, and pulse width.

[0017] Furthermore, the output parameters of the D / A conversion unit should satisfy the pulse rising edge 20% to 80% ≤ 300ps, pulse width 4 to 100ns, and simulate a single pulse waveform.

[0018] The present invention has the following advantages: through the setting of the system, the simulation reproduction of the partial discharge signal is realized, so that the staff can understand the discharge situation and avoid huge economic losses, and at the same time fill the gap in the partial discharge reproduction technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 A schematic diagram of three elements of partial discharge signal simulation is provided for the present invention.

[0020] Figure 2 The relationship diagram of f(t) and x=b / a provided by the present invention.

[0021] Figure 3 This is a relationship diagram between f(t) and a provided by the present invention.

[0022] Figure 4 This is a principle block diagram of the D / A conversion unit provided by the present invention. DETAILED DESCRIPTION

[0023] The following is a description of the implementation of the present invention by specific embodiments. People familiar with the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0024] Example 1

[0025] like Figures 1 to 4 As shown, the discharge spectrum reproduction system in the embodiment of the first aspect of the present invention comprises a control computer, a D / A conversion unit and a coupling tool, the control computer converts the spectrum in the typical partial discharge spectrum library into an editable digital signal, the D / A conversion unit converts the signal into an analog signal, and outputs it to the coupling tool to construct a typical test environment, thereby generating a corresponding programmable control typical partial discharge signal simulation environment;

[0026] The D / A conversion unit includes a storage module, a sequence generator module, a clock generator module, a digital-to-analog converter module, a low-pass filter module and an output amplifier module; specifically:

[0027] The memory module is used to load the digital representation of the waveform into the memory of the arbitrary waveform generator through the LabView application software. The clock frequency of the memory is 5 GHz. The depth of the memory indicates the length of the signal playback time. The memory size is 1.5GSa. Under the extreme output condition of 2.4k~500M sampling points per pulse, pulses can be continuously output.

[0028] The sequencer module is used to arrange the waveform into multiple segments to create the required waveform, solving the limitation of memory depth. The memory sorting only stores the key waveform parts, and the sequencer only records the waveform jumps but not the idle time, and keeps synchronization with the trigger signal generator that supports the waveform.

[0029] a clock generator module that controls the DAC module and the sequencer, thereby controlling the timing of the waveform; a memory controller that tracks waveform events in the memory and outputs them to the DAC module in the correct order; and a memory controller that stores repeated units in a loop so that they are listed only once in the waveform memory, thereby saving storage space;

[0030] The digital-to-analog converter module is used to convert the digital voltage value into an analog voltage. The number of bits of the digital-to-analog converter module will affect the vertical resolution of the memory. The higher the number of bits, the higher the vertical resolution and the more detailed the output waveform. The digital-to-analog converter module uses interpolation to achieve a higher update rate than the waveform memory. The number of bits of the memory and the digital-to-analog converter module is more than 12 bits, and the amplitude output range is 0.35 to 0.7V. Under the condition of the output in the extreme amplitude range, the output amplitude resolution is 2mV, which meets the requirements of partial discharge amplitude sequence simulation;

[0031] The low-pass filter module is used to filter the voltage steps output by the digital-to-analog converter module, which contain a large number of harmonic components, to obtain a smooth sinusoidal analog waveform;

[0032] The amplifier module is used to receive the signal after passing through the filter, and the amplifier module controls the gain and bias. According to the requirements of the partial discharge amplitude sequence simulation, the output gain and bias can be flexibly adjusted, and the distortion-free output with a high dynamic range can be achieved to ensure the linearity of signal amplitude restoration;

[0033] In the above embodiment, it should be noted that in order to achieve accurate reproduction of partial discharge pulses and timing, in terms of the selection of D / A conversion units, the DG70000 series arbitrary waveform generator (AWG) is used, and on this basis, through program control adjustment, the accurate output of partial discharge pulse waveform and timing is achieved. The arbitrary waveform generator (AWG) has an analog bandwidth of 2G, a sampling rate of up to 5GSa / s, and a minimum rise time of 200ps (20%-80%) for simulating the transmission of steep pulse signals. The accuracy of the simulated transmission of steep pulse signals is four channels, and the sampling rate of each channel is 5GSa / s; 16-bit vertical resolution; the output amplitude of each channel is 350mVpp-0.7Vpp. It can directly generate signals with a carrier of up to 5GHz, with a storage depth of 1.5G sample points for each channel, a total jitter of 10psp-p, a random jitter of 350fsrms, and a synchronization accuracy skew offset repeatability of ±10ps between any two channels. All four channels have complex sequence output plug-in functions, control interfaces LAN and USB3.0; resolution of more than 16 bits, which fully meets the technical parameter requirements for discharge waveform simulation of UHF detection methods.

[0034] Example 2

[0035] like Figures 1 to 3 As shown, the discharge spectrum reproduction system includes all the contents of embodiment 1, and in addition, the technical parameters of the storage device meet the signal simulation requirements of partial discharge;

[0036] In the above embodiment, it should be noted that, in order to achieve the simulation reproduction of the partial discharge signal, three key simulation factors are extracted through repeated analysis of the partial discharge mode: single pulse waveform, pulse timing (interval between adjacent pulses), and pulse phase. In order to fully reproduce the signal characteristics of the partial discharge, it is necessary to reproduce the partial discharge single pulse waveform, timing and phase information without distortion, such as Figure 1 shown.

[0037] Example 3

[0038] like Figures 1 to 3 As shown, the discharge spectrum reproduction system includes all the contents of embodiment 2, and in addition, the D / A conversion unit also includes a trigger, the trigger input is used to communicate information between the memory and the external device, and the trigger information changes the operation of the sequence generator, so that the selected waveform enters the digital-to-analog converter module;

[0039] In the above embodiments, it should be noted that, when precise timing functions are required, hardware or software triggering can be used, and even multiple arbitrary waveform generators can be synchronized and triggered simultaneously, in which case hardware or software triggering can also be used.

[0040] Example 4

[0041] like Figures 1 to 3 As shown, the discharge spectrum reproduction system includes all the contents of Example 3, and in addition, includes the simulation of the single pulse waveform of partial discharge, selects the double exponential pulse waveform, and constrains the pulse rising edge, pulse decay time, and pulse width;

[0042] In the above embodiment, it should be noted that the double exponential pulse function is shown in the following formula 1-1. According to the systematic study of the double exponential pulse, the double exponential pulse has four key waveform parameters, namely: pulse peak value fmax, time to reach the peak value Tmax, half peak time of the pulse trailing edge Tm, and ratios x=b / a and ym=Tm / Tmax;

[0043] From the functional relationship of the double exponential pulse

[0044] f(t)=K(e -at -e -bt )(1-1)

[0045] It can be seen that the condition for reaching the maximum value is:

[0046]

[0047] By appropriately transforming it, we get:

[0048] aT max =(lnx) / (x-1) (1-3)

[0049] From equations (1-1) and (1-3), we get:

[0050]

[0051] Based on the actual situation, b>>a, that is, x>>1, there is formula 1-5

[0052]

[0053] From the previous parameter definitions, we can get formula 1-6, and formula 1-7

[0054]

[0055]

[0056] Thus, we can solve formula 1-8

[0057]

[0058] Substituting (1-3) into (7) and using the approximation x>>1, we get formula 1-9

[0059] y m =1+0.693x / (lnx)(1-9)

[0060] The technical effect achieved by the above embodiment is: So far, a very simple relationship between x and ym has been established. Combining equations 1-1 and 1-9, it can be concluded that by controlling different values ​​of x, the double exponential pulse shape and the rising and falling edges can be accurately controlled. Based on this idea, by programming and drawing f(t), the relationship between x=b / a and a is as follows: Figure 2-Figure 3 shown.

[0061] Example 5

[0062] like Figures 1 to 3 As shown, the discharge spectrum reproduction system includes all the contents of Example 4. In addition, the output parameters of the D / A conversion unit should meet the pulse rising edge 20% to 80% ≤ 300ps, the pulse width 4 to 100ns, and the single pulse waveform simulation;

[0063] In the above embodiment, it should be noted that by Figure 2-Figure 3It can be seen that among the influencing factors of the double exponential function, when a is fixed, the x=b / a value plays a decisive role in the rising edge time of the double exponential function; when x=b / a is fixed, the a value plays a decisive role in the pulse falling time. When the K value is x=b / a and the a value is fixed, the pulse amplitude can be reasonably adjusted by modifying the K value to ensure the normalization of the amplitudes of different pulses.

[0064] By properly setting x=b / a, a, and K value, a pulse waveform with normalized amplitude, different rising edges, and different falling edges can be obtained, thereby realizing a specific constrained waveform that meets the requirements of the D / A conversion unit detection method.

Claims

1. A discharge spectrum reproduction system, the system comprising a control computer, a D / A conversion unit and a coupling tool, the control computer converts the spectrum in the typical partial discharge spectrum library into an editable digital signal, the D / A conversion unit converts the signal into an analog signal, and outputs it to the coupling tool to construct a typical test environment, thereby generating a corresponding programmable controllable typical partial discharge signal simulation environment; It is characterized in that The D / A conversion unit includes a storage module, a sequence generator module, a clock generator module, a digital-to-analog converter module, a low-pass filter module and an output amplifier module; specifically: The memory module is used to load the digital representation of the waveform into the memory of the arbitrary waveform generator through the LabView application software. The clock frequency of the memory is 5 GHz. The depth of the memory indicates the length of the signal playback time. The memory size is 1.5GSa. Under the extreme output condition of 2.4k~500M sampling points per pulse, pulses can be continuously output. The sequencer module is used to arrange the waveform into multiple segments to create the required waveform, solving the limitation of memory depth. The memory sorting only stores the key waveform parts, and the sequencer only records the waveform jumps but not the idle time, and keeps synchronization with the trigger signal generator that supports the waveform. a clock generator module that controls the DAC module and the sequencer, thereby controlling the timing of the waveform; a memory controller that tracks waveform events in the memory and outputs them to the DAC module in the correct order; and a memory controller that stores repeated units in a loop so that they are listed only once in the waveform memory, thereby saving storage space; The digital-to-analog converter module is used to convert the digital voltage value into an analog voltage. The number of bits of the digital-to-analog converter module will affect the vertical resolution of the memory. The higher the number of bits, the higher the vertical resolution and the more detailed the output waveform. The digital-to-analog converter module uses interpolation to achieve a higher update rate than the waveform memory. The number of bits of the memory and the digital-to-analog converter module is more than 12 bits, and the amplitude output range is 0.35 to 0.7V. Under the condition of the output in the extreme amplitude range, the output amplitude resolution is 2mV, which meets the requirements of partial discharge amplitude sequence simulation; The low-pass filter module is used to filter the voltage steps output by the digital-to-analog converter module, which contain a large number of harmonic components, to obtain a smooth sinusoidal analog waveform; The amplifier module is used to receive the signal after passing through the filter, and the amplifier module controls the gain and bias. According to the requirements of the partial discharge amplitude sequence simulation, the output gain and bias can be flexibly adjusted, and the distortion-free output with a high dynamic range can be ensured to ensure the linearity of the signal amplitude restoration.

2. The discharge spectrum reproduction system according to claim 1, characterized in that: The technical parameters of the storage device meet the signal simulation requirements of partial discharge.

3. The discharge spectrum reproduction system according to claim 1, characterized in that: The D / A conversion unit also includes a trigger, the trigger input is used to communicate information between the memory and the external device, and the trigger information changes the operation of the sequence generator, thereby allowing the selected waveform to enter the digital-to-analog converter module.

4. The discharge spectrum reproduction system according to claim 1, characterized in that: It also includes the simulation of single pulse waveform of partial discharge, using double exponential pulse waveform and setting constraints on pulse rising edge, pulse decay time and pulse width.

5. The discharge spectrum reproduction system according to claim 4, characterized in that: The output parameters of the D / A conversion unit should meet the pulse rising edge 20% to 80% ≤ 300ps, pulse width 4 to 100ns, and simulate a single pulse waveform.

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