阅读说明：本技术 一种用于特高压换流站套管监测的高精度同步采集装置 (High-precision synchronous acquisition device for monitoring extra-high voltage converter station sleeve ) 是由 王豪舟 黎炜 史磊 徐辉 柴斌 刘舒杨 雷战斐 张立明 谢伟锋 李洋 杨雨琪 于 2020-12-22 设计创作，主要内容包括：本申请实施例提供了一种用于特高压换流站套管监测的高精度同步采集装置,包括信号调理电路、并行模数转换单元和中央处理模块。信号调理单元用于采集多个套管末端适配器输出的多路接地电流信号；并行模数转换单元的输入端与信号调理单元的输出端连接,用于基于周期采样脉冲对多路接地电流信号进行精确周期采样,得到多个接地电流数据；中央处理模块用于向并行模数转换单元输出周期采样脉冲,并接收并行模数转换单元输出的接地电流数据,并启动DMA搬移接地电流数据。由于其在执行模数转换的时候是基于中央处理模块输出的周期采样脉冲实现的,因此通过该脉冲的约束实现了对套管的接地电流信号的高精度采样。(The embodiment of the application provides a high-precision synchronous acquisition device for monitoring an extra-high voltage converter station sleeve, which comprises a signal conditioning circuit, a parallel analog-to-digital conversion unit and a central processing module. The signal conditioning unit is used for acquiring multi-path grounding current signals output by the plurality of sleeve tail end adapters; the input end of the parallel analog-to-digital conversion unit is connected with the output end of the signal conditioning unit and is used for carrying out accurate periodic sampling on the multi-path grounding current signals based on periodic sampling pulses to obtain a plurality of grounding current data; the central processing module is used for outputting periodic sampling pulses to the parallel analog-to-digital conversion unit, receiving grounding current data output by the parallel analog-to-digital conversion unit and starting the DMA to move the grounding current data. Because the sampling is realized based on the periodic sampling pulse output by the central processing module when the analog-to-digital conversion is carried out, the high-precision sampling of the grounding current signal of the casing is realized through the constraint of the pulse.)

1. The utility model provides a high accuracy synchronization acquisition device for extra-high voltage converter station sleeve pipe monitoring which characterized in that, includes signal conditioning circuit, parallel analog-to-digital conversion unit and central processing module, wherein:

the input end of the signal conditioning unit is respectively connected with a plurality of sleeve terminal adapters of the extra-high voltage converter station and is used for acquiring a plurality of paths of grounding current signals output by the sleeve terminal adapters;

the input end of the parallel analog-to-digital conversion unit is connected with the output end of the signal conditioning unit and is used for carrying out accurate periodic sampling on the multi-path grounding current signals based on periodic sampling pulses to obtain a plurality of grounding current data and outputting the grounding current data to the central processing module;

the central processing module is connected with the output end of the parallel analog-to-digital conversion unit and used for outputting the periodic sampling pulse to the parallel analog-to-digital conversion unit, receiving the grounding current data output by the parallel analog-to-digital conversion unit and starting a DMA (direct memory access) to move the grounding current data.

2. The high precision synchronous sampling device of claim 1, wherein the central processing module comprises a processor, a configuration unit, an external precision clock unit, an analog conversion unit, and a voltage controlled crystal oscillator, wherein:

the processor is respectively connected with the configuration unit, the analog conversion unit and the voltage-controlled crystal oscillator;

the voltage-controlled crystal oscillator is also connected with the analog conversion unit and the configuration unit respectively;

the configuration unit is also connected with the accurate time unit and the parallel analog-to-digital conversion unit.

3. The high precision synchronous sampling device of claim 2, wherein the external precision clock unit is configured to output standard time pulses to the configuration unit.

4. A high precision synchronous sampling device according to claim 3, wherein the configuration unit is provided with a clock synchronization module, wherein:

the clock synchronization module is used for receiving the standard time pulse, locking the standard time pulse and outputting the periodic sampling pulse to the parallel analog-to-digital conversion unit.

5. The high-precision sampling device of claim 2, wherein the analog conversion unit is configured to output a control voltage to the voltage controlled crystal oscillator based on a control voltage adjustment command output by the processor;

the voltage-controlled crystal oscillator is used for outputting control frequency pulse signals to the processor and the configuration unit respectively based on the control voltage.

6. The high-precision synchronous acquisition device according to claim 2, wherein the central processing module is configured to perform a time synchronization process according to a standard time pulse, and specifically includes the following steps:

firstly, calculating the time difference of an internal precise clock of a processor corresponding to two standard time pulses, and recording the corresponding voltage-controlled crystal oscillator control voltage;

then, sequentially changing the control voltage of the voltage-controlled crystal oscillator and recalculating the time difference;

fitting the plurality of control voltages and the plurality of time difference values to obtain an approximate linear relation between the control voltage change of the voltage-controlled crystal oscillator and the time difference values;

obtaining a slope curve of the voltage-controlled crystal oscillator according to the approximate linear relation, and generating a mapping table of a digital value and the control voltage based on the slope curve;

restoring the control voltage to an initial value, and then calculating the time difference value and the time difference value of the latest sampling pulse of the corresponding standard time pulse and the internal accurate clock;

calculating a clock frequency setting target time difference value according to the pulse length of the standard time pulse and the internal precision clock, and setting a target sampling pulse time difference value according to the frequency of the periodic sampling pulse and the clock frequency of the internal precision clock module;

adjusting the control voltage to make the time difference value converge to the target time difference value;

and adjusting the control voltage to make the sampling pulse time difference value converge to the target sampling pulse time difference value.

7. The apparatus according to claim 6, wherein the central processing module is configured to determine the time stamp of the DMA corresponding data.

Technical Field

The application relates to the technical field of electric power, in particular to a high-precision synchronous acquisition device for monitoring a casing of an extra-high voltage converter station.

Background

The sleeve on the network side of the converter station is easily affected by high dielectric and thermal stress to cause sleeve failure, and the sleeve failure is very easy to cause accidents such as fire and the like, so that the online monitoring of the sleeve is an indispensable part of an online monitoring system of core power equipment. When the sleeve is monitored, the insulation condition of the sleeve can be judged according to parameters such as the tangent value, the capacitance, the insulation resistance, the dielectric loss value and the like of the dielectric loss of the sleeve. The dielectric loss value is the ratio of the active component and the reactive component of the current in the dielectric medium under the action of the alternating voltage, and under a certain voltage and frequency, the dielectric loss value reflects the energy loss in unit volume in the dielectric medium, and is related to the volume size and the size of the dielectric medium, so that the insulation condition of the sleeve can be effectively evaluated based on the accurately measured dielectric loss value.

However, factors affecting the measurement accuracy of the dielectric loss value are many, such as the ambient temperature and humidity, the fluctuation of the grid frequency and the PT angle difference, so that it is difficult to accurately measure the absolute dielectric loss value of the casing. Therefore, the dielectric loss value is generally measured by a relative measurement method, specifically, the ground currents of a plurality of bushings under the same-phase operation condition are measured, the relative loss dielectric tangent value between devices is measured by using the ground currents as reference, and the insulation condition of the bushings is judged according to the change of the relative dielectric loss tangent angle.

In summary, the basis of the relative measurement method is to perform high-precision synchronous acquisition on the ground current of the bushing, so that a user can indirectly calculate the dielectric loss value according to the ground current, and further realize the evaluation of the insulation condition of the bushing according to the dielectric loss value.

Disclosure of Invention

In order to solve the problems, the application provides a high-precision synchronous acquisition device for monitoring a casing of an extra-high voltage converter station, which is used for carrying out high-precision acquisition on a grounding current signal of the casing.

In view of this, the application discloses a high accuracy synchronous acquisition device for monitoring of extra-high voltage converter station sleeve pipe, including signal conditioning circuit, parallel analog-to-digital conversion unit and central processing module, wherein:

the input end of the signal conditioning unit is respectively connected with a plurality of sleeve terminal adapters of the extra-high voltage converter station and is used for acquiring a plurality of paths of grounding current signals output by the sleeve terminal adapters;

the input end of the parallel analog-to-digital conversion unit is connected with the output end of the signal conditioning unit and is used for carrying out accurate periodic sampling on the multi-path grounding current signals based on periodic sampling pulses to obtain a plurality of grounding current data and outputting the grounding current data to the central processing module;

the central processing module is connected with the output end of the parallel analog-to-digital conversion unit and used for outputting the periodic sampling pulse to the parallel analog-to-digital conversion unit, receiving the grounding current data output by the parallel analog-to-digital conversion unit and starting a DMA (direct memory access) to move the grounding current data.

Optionally, the central processing module includes a processor, a configuration unit, an external precision clock unit, an analog conversion unit, and a voltage-controlled crystal oscillator, where:

the processor is respectively connected with the configuration unit, the analog conversion unit and the voltage-controlled crystal oscillator;

the voltage-controlled crystal oscillator is also connected with the analog conversion unit and the configuration unit respectively;

the configuration unit is also connected with the accurate time unit and the parallel analog-to-digital conversion unit.

Optionally, the external precision clock unit is configured to output a standard time pulse to the configuration unit.

Optionally, the configuration unit is provided with a clock synchronization module, wherein:

the clock synchronization module is used for receiving the standard time pulse, locking the standard time pulse and outputting the periodic sampling pulse to the parallel analog-to-digital conversion unit.

Optionally, the analog conversion unit is configured to output a control voltage to the voltage controlled crystal oscillator based on a control voltage adjustment instruction output by the processor;

the voltage-controlled crystal oscillator is used for outputting control frequency pulse signals to the processor and the configuration unit respectively based on the control voltage.

Optionally, the central processing module is configured to perform time synchronization processing according to a standard time pulse, and specifically includes the following steps:

firstly, calculating the time difference of an internal precise clock of a processor corresponding to two standard time pulses, and recording the corresponding voltage-controlled crystal oscillator control voltage;

then, sequentially changing the control voltage of the voltage-controlled crystal oscillator and recalculating the time difference;

fitting the plurality of control voltages and the plurality of time difference values to obtain an approximate linear relation between the control voltage change of the voltage-controlled crystal oscillator and the time difference values;

obtaining a slope curve of the voltage-controlled crystal oscillator according to the approximate linear relation, and generating a mapping table of a digital value and the control voltage based on the slope curve;

restoring the control voltage to an initial value, and then calculating the time difference value and the time difference value of the latest sampling pulse of the corresponding standard time pulse and the internal accurate clock;

calculating a clock frequency setting target time difference value according to the pulse length of the standard time pulse and the internal precision clock, and setting a target sampling pulse time difference value according to the frequency of the periodic sampling pulse and the clock frequency of the internal precision clock module;

adjusting the control voltage to make the time difference value converge to the target time difference value;

and adjusting the control voltage to make the sampling pulse time difference value converge to the target sampling pulse time difference value.

Optionally, the central processing module is configured to determine a time stamp of data corresponding to the DMA.

According to the technical scheme, the high-precision synchronous acquisition device for monitoring the ultrahigh-voltage converter station sleeve comprises a signal conditioning circuit, a parallel analog-to-digital conversion unit and a central processing module. The signal conditioning unit is used for acquiring multi-path grounding current signals output by the plurality of sleeve tail end adapters; the input end of the parallel analog-to-digital conversion unit is connected with the output end of the signal conditioning unit and is used for carrying out accurate periodic sampling on the multi-path grounding current signals based on periodic sampling pulses to obtain a plurality of grounding current data; the central processing module is used for outputting periodic sampling pulses to the parallel analog-to-digital conversion unit, receiving grounding current data output by the parallel analog-to-digital conversion unit and starting the DMA to move the grounding current data. Because the sampling is realized based on the periodic sampling pulse output by the central processing module when the analog-to-digital conversion is carried out, the high-precision sampling of the grounding current signal of the casing is realized through the constraint of the pulse.

Drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

FIG. 1 is a block diagram of a high-precision synchronous acquisition device for monitoring an extra-high voltage converter station casing according to an embodiment of the present application;

FIG. 2 is a block diagram of a central processing module according to an embodiment of the present application;

fig. 3 is a flowchart of a time synchronization process according to an embodiment of the present application;

fig. 4 is a timing diagram of a DMA according to an embodiment of the present application.

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

Examples

Fig. 1 is a block diagram of a high-precision synchronous acquisition device for monitoring an extra-high voltage converter station bushing according to an embodiment of the present application.

The high-precision synchronous acquisition device provided by the embodiment is used for carrying out high-precision acquisition on the grounding current of the network side sleeve of the ultra-high voltage converter station, so that a user can calculate the dielectric loss value of the sleeve according to the grounding current and further realize the evaluation on the insulation condition of the sleeve according to the dielectric loss value.

As shown in fig. 1, the high-precision synchronous acquisition device includes a signal conditioning circuit 10, a parallel analog-to-digital conversion unit 20, and a central processing module 30. The signal conditioning circuit is connected with a tap adapter of a sleeve to be monitored, and the parallel analog-to-digital conversion unit is respectively connected with the signal conditioning circuit and the central processing module.

The signal conditioning circuit comprises a plurality of signal conditioning units, wherein each signal conditioning unit is used for receiving one path of grounding current signal output by a bushing end screen adapter, conditioning the grounding current signal, namely, sequentially carrying out jitter elimination, filtering, protection and amplification on the signal, and outputting the processed grounding current signal to a parallel analog-to-digital conversion circuit for analog-to-digital conversion.

After the parallel analog-to-digital conversion circuit obtains a plurality of paths of grounding current signals, analog-to-digital conversion is carried out on each path of grounding current signals based on the constraint of periodic sampling pulses output by the central processing module to obtain a plurality of grounding current data, and the grounding current data are output to the central processing module.

The central processing module is connected with the output end of the parallel analog-to-digital conversion module through a corresponding parallel port, a user outputs the periodic sampling pulse to the parallel analog-to-digital conversion module, receives grounding current data output by the parallel analog-to-digital conversion circuit, and starts a DMA (direct memory access) to move the external low-current data, so that high-precision sampling of the grounding current signal of the sleeve is realized.

According to the technical scheme, the high-precision synchronous acquisition device for monitoring the ultrahigh-voltage converter station sleeve comprises a signal conditioning circuit, a parallel analog-to-digital conversion unit and a central processing module. The signal conditioning unit is used for acquiring multi-path grounding current signals output by the plurality of sleeve tail end adapters; the input end of the parallel analog-to-digital conversion unit is connected with the output end of the signal conditioning unit and is used for carrying out accurate periodic sampling on the multi-path grounding current signals based on periodic sampling pulses to obtain a plurality of grounding current data; the central processing module is used for outputting periodic sampling pulses to the parallel analog-to-digital conversion unit, receiving grounding current data output by the parallel analog-to-digital conversion unit and starting the DMA to move the grounding current data. Because the sampling is realized based on the periodic sampling pulse output by the central processing module when the analog-to-digital conversion is carried out, the high-precision sampling of the grounding current signal of the casing is realized through the constraint of the pulse.

The central processing module in this embodiment includes a processor 31, a configuration unit 32, an external precision clock unit 33, an analog conversion unit 34, and a voltage controlled crystal oscillator 35, as shown in fig. 2, the processor is connected to the configuration unit, the analog conversion unit, and the voltage controlled crystal oscillator, respectively; the voltage-controlled crystal oscillator is also connected with the analog conversion unit and the configuration unit respectively; the configuration unit is also connected with the precise time unit and the parallel analog-to-digital conversion unit.

The external precision clock unit is used for outputting standard time pulses to the configuration unit. The configuration unit is provided with a clock synchronization module. The clock synchronization module is used for receiving the standard time pulse, locking the standard time pulse and outputting a periodic sampling pulse of the standard time pulse to the parallel analog-to-digital conversion unit along the boundary of the standard time pulse.

The analog conversion unit is used for outputting a control voltage to the voltage-controlled crystal oscillator based on a control voltage adjusting instruction output by the processor; the voltage-controlled crystal oscillator is used for outputting control frequency pulse signals with the same frequency to the processor and the configuration unit respectively based on the control voltage. Through automatic frequency control, the frequency deviation of the voltage-controlled crystal oscillator is eliminated in real time, high-precision synchronous acquisition is completed, and the synchronous precision can be controlled within 100 nanoseconds.

The central processing module in this embodiment is configured to perform time synchronization processing according to a standard time pulse, and the specific steps are shown in fig. 3, where:

t_sa standard time pulse period provided for an external precision clock unit;

t_etiming of standard time pulses provided by locking external precision clock units for internal precision clock modules；

t₁,t₂,t₃,t₄Locking the time scale of the last four sampling pulses for the internal precise clock module in a circulating manner;

V_Daccontrolling a voltage for a voltage controlled crystal oscillator;

f_inneris the clock frequency of the precision clock module;

f_sis the sampling frequency.

1. Firstly, calibration is carried out, the time difference value of two times of standard time pulses output by the external precise clock unit corresponding to the internal precise clock module is calculated, and the control voltage V of the corresponding voltage-controlled crystal oscillator is recorded_DacThe calculation formula is as follows:

2. then sequentially changing the control voltage of the voltage controlled crystal oscillatorMake the voltage-controlled crystal oscillator control voltage V_Dac′And recalculating the time difference value of the internal precise clock module corresponding to the two pulses of the external precise clock unit, wherein the formula is as follows:

3. calculating an approximate linear relationship between the control voltage variation of the voltage controlled crystal oscillator and the time variation of the internal precision clock, and the formula is as follows:

4. is divided intoWith sections using different V_DacRepeating the steps 1-3 within the range of the voltage controlled crystal oscillator control voltageAnd obtaining the approximate linear relation between the control voltage change of the voltage-controlled crystal oscillator control voltage segmentation and the time change of the internal accurate clock.

And obtaining a slope curve of the voltage-controlled crystal oscillator according to the approximate linear relation, generating a mapping table of a 12-bit digital value and an analog control voltage, and generating a digital control word by inquiring the mapping table, so that the frequency control can be conveniently finished by subsequently controlling the parallel analog-to-digital conversion unit.

5. Restoring the control voltage of a voltage controlled crystal oscillator to an initial V_DacThen, the time difference value of the internal precise clock corresponding to the two pulses of the external precise clock unit is calculatedAnd the time difference t between the standard time pulse of the corresponding external precise clock unit and the latest sampling pulse of the internal precise clock module_delta。

6. Setting a target time difference value according to the length of a standard time pulse of an external precision clock unit and the clock frequency of an internal precision clockSetting a target sampling pulse time difference value according to a sampling frequency and a clock frequency of an internal precision clock moduleThe calculation formula is as follows:

7. by adjusting V_DacHas a value such thatAndclose to, V_DacAdjustment value DeltaV_DacThe calculation formula is as follows, k passes through V according to the mapping table obtained in step 4_DacAnd checking that the frequency precision of the voltage-controlled crystal oscillator is below 0.01ppm at the moment.

ΔV_Dac＝k*Δt_e

8. By adjusting V_DacIs such that t_deltaAndclose to, V_DacAdjustment value DeltaV_DacThe calculation formula is as follows, k passes through V according to the mapping table obtained in step 4_DacIs found by

ΔV_Dac＝k*Δt_delta

9. Repeat Steps 7, 8 ensureAnd t_deltaConverge at the same timeAnd

in addition, the starting time of the DMA in this application is random, so it is necessary to determine the time scale of the data corresponding to the DMA, as shown in fig. 4, after waiting 2 times for the DMA count to increase in the external precision clock unit standard time pulse interrupt, it can be confirmed that the data of the subscript n-1 corresponds to the time indicated by the external precision clock unit standard time pulse.

The embodiments in the present specification are described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same and similar parts among the embodiments are referred to each other.

As will be appreciated by one of skill in the art, embodiments of the present application may be provided as a method, apparatus, or computer program product. Accordingly, embodiments of the present application may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, embodiments of the present application may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein.

Embodiments of the present application are described with reference to flowchart illustrations and/or block diagrams of methods, terminal devices (systems), and computer program products according to embodiments of the application. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing terminal to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing terminal, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing terminal to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be loaded onto a computer or other programmable data processing terminal to cause a series of operational steps to be performed on the computer or other programmable terminal to produce a computer implemented process such that the instructions which execute on the computer or other programmable terminal provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

While preferred embodiments of the present application have been described, additional variations and modifications of these embodiments may occur to those skilled in the art once they learn of the basic inventive concepts. Therefore, it is intended that the appended claims be interpreted as including the preferred embodiment and all such alterations and modifications as fall within the true scope of the embodiments of the application.

Finally, it should also be noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or terminal that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or terminal. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other like elements in a process, method, article, or terminal that comprises the element.

The technical solutions provided by the present application are introduced in detail, and specific examples are applied in the description to explain the principles and embodiments of the present application, and the descriptions of the above examples are only used to help understanding the method and the core ideas of the present application; meanwhile, for a person skilled in the art, according to the idea of the present application, there may be variations in the specific embodiments and the application scope, and in summary, the content of the present specification should not be construed as a limitation to the present application.