阅读说明：本技术 用于配网ct误差校验过程的数据同步方法 (Data synchronization method for distribution network CT error checking process ) 是由 蒋红亮 王锦义 徐政 王申华 方小方 方跃进 熊庄 管新涌 何华庆 金志武 何湘 于 2020-05-09 设计创作，主要内容包括：本申请实施例提出了用于配网CT误差校验过程的数据同步方法,适用于至少两个直流互感器输出信号的同步过程。包括按预设采样频率对各电流互感器的输出数据进行采样；获取固定时延,经固定时延后将采样得到的输出数据发送至合并单元；在合并单元中采用重采样同步的方式对得到的输出数据进行同步处理。由于重采样算法使用同源的FPGA时钟对采集器数据进行插值运算,同时重采样算法采用抛物线插值算法,具有很高的精确度,可满足直流系统数据精度要求。(The embodiment of the application provides a data synchronization method for a distribution network CT error checking process, which is suitable for a synchronization process of output signals of at least two direct current transformers. Sampling output data of each current transformer according to a preset sampling frequency; acquiring fixed time delay, and sending output data obtained by sampling to a merging unit after the fixed time delay; and performing synchronous processing on the obtained output data in a resampling synchronization mode in the merging unit. Because the resampling algorithm uses the homologous FPGA clock to carry out interpolation operation on the data of the collector, and simultaneously, the resampling algorithm adopts the parabolic interpolation algorithm, the resampling algorithm has high accuracy and can meet the requirement of the data accuracy of a direct current system.)

1. The data synchronization method for the distribution network CT error check process is suitable for the synchronization process of output signals of at least two direct current transformers, and is characterized by comprising the following steps:

sampling output data of each current transformer according to a preset sampling frequency;

acquiring fixed time delay, and sending output data obtained by sampling to a merging unit after the fixed time delay;

and performing synchronous processing on the obtained output data in a resampling synchronization mode in the merging unit.

2. The data synchronization method for the distribution network CT error checking process according to claim 1, wherein the synchronizing the obtained output data in the merging unit by means of resampling synchronization includes:

performing time operation based on the FPGA clock in the merging unit to obtain marked time;

and performing secondary acquisition on the obtained output data by taking the marking time as a time reference to finish synchronous processing.

3. The data synchronization method for the distribution network CT error checking process according to claim 2, wherein the performing time operation based on the FPGA clock in the merging unit to obtain the marked time comprises:

and calling FPGA hardware logic in the merging unit to carry out protocol analysis, and adding an operating frequency count value of the FPGA to carry out interpolation operation on the collector data to obtain the marking time.

4. The data synchronization method for the distribution network CT error checking process according to claim 2, wherein the performing of the secondary acquisition of the obtained output data with the marked time as the time reference to complete the synchronization process comprises:

the A/D conversion modules of different channels start data acquisition by taking the time reference as the time reference, and the data synchronization and message framing module takes the time reference as a message sequence number zero clearing mark to realize data synchronization among different channels.

5. The data synchronization method for the distribution network CT error checking process as claimed in claim 1, wherein said obtaining a fixed time delay comprises:

applying current or voltage to the merging unit by using a current booster or a voltage booster, testing the current or voltage analog quantity by using an electronic transformer tester, and receiving a digital message output by the merging unit;

and calculating the angular difference and the ratio difference of the two to obtain the fixed time delay.

6. The data synchronization method for the distribution network CT error checking process as recited in claim 1, further comprising a data preprocessing method before sampling the output data of each current transformer according to a preset sampling frequency.

7. The data synchronization method for the distribution network CT error checking process according to claim 6, wherein the data preprocessing method comprises:

receiving a pulse per second synchronization signal sent by a GPS unit;

judging the correctness of the pulse per second signal, and selectively generating a sampling signal sent to an A/D converter according to different judgment results;

after the A/D converter receives the sampling signal, the first signal connected to the input end of the A/D converter is converted, and the converted signal is transmitted to the data synchronization module;

and the control data receiving module transmits the received second signal to the data synchronization module, and the data synchronization module carries out synchronization processing on the received converted signal and the second signal.

8. The data synchronization method for the distribution network CT error checking process according to claim 7, wherein the determining the correctness of the pulse per second signal and selectively generating the sampling signal to be sent to the a/D converter according to the determination result comprises:

if the second pulse signal format is correct, sending a sampling signal representing the actual time interval to the A/D converter;

if the pulse per second signal is in error, a sampling signal of a standard time interval is sent to the A/D converter.

9. The method of claim 8, wherein sending a sampling signal representative of the actual time interval to the a/D converter if the pulse-per-second signal is in the correct format comprises:

when the pulse per second signal format is correct, a signal time interval between pulse per second signals is acquired, a sampling signal format is determined based on the time interval, and the sampling signal is sent to the A/D converter.

Technical Field

The invention belongs to the field of data processing, and particularly relates to a data synchronization method for a distribution network CT error check process.

Background

With the development of urbanization, in order to improve the power supply reliability of a distribution network and improve the service quality and meet the requirement of the beautiful life of people on high-quality power supply service, countries and companies all invest a large amount of manpower and material resources to strengthen the construction, upgrading and transformation of the distribution network. Especially, a large number of distribution network automation devices all contain mutual inductor equipment (such as PT or CT), and the equipment cannot meet the requirements of live operation due to the quality, process, structure and the like, so that accidents occur. Therefore, aiming at the research of the uninterrupted operation technology of the distribution network automation equipment containing the mutual inductor, the problem that the equipment is damaged or broken due to improper operation to affect the safety of the equipment and operators can be reduced or avoided, the research of the uninterrupted operation technology of the distribution network automation equipment is developed for the first time, the blank of the company in the aspect is filled, the power failure of engineering prearrangement is reduced, and the power supply reliability is improved.

The live-line disconnection drainage wire is the most basic conventional live-line work project of a 10kV overhead distribution line and accounts for about 60% of the live-line work times of each unit of a power company every year. In order to ensure the safety of live working, safety regulations require that when a no-load line is disconnected and connected in a live state, a circuit breaker (switch) and an isolating switch (knife switch) at the other end of the line are required to be confirmed to be disconnected, and a transformer and a voltage transformer which are connected to the line side can be carried out after the transformer and the voltage transformer are confirmed to be withdrawn from operation. However, with the overall progress of the automatic transformation work of the distribution lines of the urban power grid, various load switches are widely used, and a transformer (energy-taking PT for short) for providing power for a controller and an operating device of the load switch cannot quit operation during live-line work. Whether the energy taking PT can be installed in a charged state or not and the drainage wire with the PT is disconnected become the difficult problems which need to be solved urgently in the current charged work.

The mutual inductor is an important component of an electric energy metering device and is a legal metering appliance for performing fair and fair trade settlement between a power generation company and a power grid company, between the power grid company and a power supply company, between the power supply company and power users and accurately calculating and checking technical and economic indexes in a power system. According to the current national verification regulations, the transformers (including voltage transformers and current transformers) used for metering in the power grid must be regularly subjected to error characteristic detection. According to the conventional detection method, the error characteristic detection can be carried out only by taking an operating transformer off-line, which inevitably affects the power supply reliability. And the electric power system in China has a huge number of power transformers, the error performance workload of the power system in power failure test is huge, time and labor are wasted, and real data in a three-phase electrified state cannot be obtained.

Disclosure of Invention

In order to solve the defects and shortcomings in the prior art, the invention provides a data synchronization method for a distribution network CT error check process, which is suitable for the synchronization process of output signals of at least two direct current transformers.

Specifically, the data synchronization method for the distribution network CT error check process includes:

sampling output data of each current transformer according to a preset sampling frequency;

acquiring fixed time delay, and sending output data obtained by sampling to a merging unit after the fixed time delay;

and performing synchronous processing on the obtained output data in a resampling synchronization mode in the merging unit.

Optionally, the performing, in the merging unit, synchronization processing on the obtained output data in a resampling synchronization manner includes:

performing time operation based on the FPGA clock in the merging unit to obtain marked time;

and performing secondary acquisition on the obtained output data by taking the marking time as a time reference to finish synchronous processing.

Optionally, the performing time operation based on the FPGA clock in the merging unit to obtain the marked time includes:

and calling FPGA hardware logic in the merging unit to carry out protocol analysis, and adding an operating frequency count value of the FPGA to carry out interpolation operation on the collector data to obtain the marking time.

Optionally, the performing, by using the marked time as a time reference, secondary acquisition on the obtained output data to complete synchronous processing includes:

the A/D conversion modules of different channels start data acquisition by taking the time reference as the time reference, and the data synchronization and message framing module takes the time reference as a message sequence number zero clearing mark to realize data synchronization among different channels.

Optionally, the obtaining the fixed time delay includes:

applying current or voltage to the merging unit by using a current booster or a voltage booster, testing the current or voltage analog quantity by using an electronic transformer tester, and receiving a digital message output by the merging unit;

and calculating the angular difference and the ratio difference of the two to obtain the fixed time delay.

Optionally, a data preprocessing method is further included before sampling the output data of each current transformer according to a preset sampling frequency.

Optionally, the data preprocessing method includes:

receiving a pulse per second synchronization signal sent by a GPS unit;

judging the correctness of the pulse per second signal, and selectively generating a sampling signal sent to an A/D converter according to different judgment results;

after the A/D converter receives the sampling signal, the first signal connected to the input end of the A/D converter is converted, and the converted signal is transmitted to the data synchronization module;

and the control data receiving module transmits the received second signal to the data synchronization module, and the data synchronization module carries out synchronization processing on the received converted signal and the second signal.

Optionally, the determining the correctness of the pulse per second signal and selectively generating the sampling signal sent to the a/D converter according to different determination results includes:

if the second pulse signal format is correct, sending a sampling signal representing the actual time interval to the A/D converter;

if the pulse per second signal is in error, a sampling signal of a standard time interval is sent to the A/D converter.

Optionally, if the format of the pulse per second signal is correct, sending a sampling signal representing the actual time interval to the a/D converter includes:

when the pulse per second signal format is correct, a signal time interval between pulse per second signals is acquired, a sampling signal format is determined based on the time interval, and the sampling signal is sent to the A/D converter.

The technical scheme provided by the invention has the beneficial effects that:

because the resampling algorithm uses the homologous FPGA clock to carry out interpolation operation on the data of the collector, and simultaneously, the resampling algorithm adopts the parabolic interpolation algorithm, the resampling algorithm has high accuracy and can meet the requirement of the data accuracy of a direct current system.

Drawings

In order to more clearly illustrate the technical solution of the present invention, the drawings needed to be used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on the drawings without creative efforts.

Fig. 1 is a schematic flowchart of a data synchronization method for a distribution network CT error checking process according to an embodiment of the present application;

fig. 2 is a schematic flowchart of a data preprocessing method according to an embodiment of the present application;

fig. 3 is a schematic diagram of a preprocessing step performed by the merging unit according to an embodiment of the present application.

Detailed Description

To make the structure and advantages of the present invention clearer, the structure of the present invention will be further described with reference to the accompanying drawings.