阅读说明：本技术 一种低实时光纵同步方法及电力专用cpu芯片 (Low real-time optical longitudinal synchronization method and special electric power CPU chip ) 是由 李鹏 戴必翔 陈新之 习伟 赵继光 丁毅 张全 林朝阳 董腾 姚浩 于杨 于 2020-04-28 设计创作，主要内容包括：本发明属于电力系统继电保护的光纵同步领域,涉及一种低实时光纵同步方法及电力专用CPU芯片。本发明所要解决的技术问题在于提供一种基于国产电力专用CPU芯片的低实时光纵同步方法。光纵保护对数据处理的实时性要求比较高,在采用传统光纵同步算法后会造成光纵数据处理有延时,会对继电保护的光纵保护性能有影响。本发明提供一种基于国产电力专用CPU芯片的低实时光纵同步方法,解决了在低实时情况下的光纵同步,并且同步后使得纵联差动两侧继电保护装置的角度差符合纵联差动的动作要求。(The invention belongs to the field of optical longitudinal synchronization of relay protection of a power system, and relates to a low real-time optical longitudinal synchronization method and a special CPU chip for power. The invention aims to solve the technical problem of providing a low real-time optical longitudinal synchronization method based on a domestic power special CPU chip. The optical longitudinal protection has a high real-time requirement on data processing, and the optical longitudinal data processing is delayed after a traditional optical longitudinal synchronization algorithm is adopted, so that the optical longitudinal protection performance of the relay protection is influenced. The invention provides a low real-time optical longitudinal synchronization method based on a domestic electric power special CPU chip, which solves the optical longitudinal synchronization under the low real-time condition and enables the angle difference of relay protection devices at two sides of a longitudinal differential to meet the action requirement of the longitudinal differential after synchronization.)

1. A low real-time optical longitudinal synchronization method is characterized in that: the method comprises the following steps:

the local side device receives the optical longitudinal message sent by the opposite side device, and the receiving time is CNT₁Representing the count of an internal 64-bit counter;

obtaining count CNT of local side internal 64-bit counter₂And microsecond time US₂A reference of (1);

calculating CNTs₂－CNT₁=CNT_xCorresponding microsecond time US_x；

Microsecond time US for receiving optical longitudinal message sent by opposite side by local side through reference backward₁＝US₂－US_x；

The time for sending the optical longitudinal message at the local side adopts the time US of entering interruption₃；

Abstracting the graph formed by connecting the sending and receiving time points of the optical longitudinal messages into an isosceles trapezoid, wherein the side length of the trapezoid at the side is △ t_r= US₃－US₁Side length △ t of trapezoid on opposite side_n= US₁’－US₃’，US₁' receiving longitudinal message time on opposite side, US₃' is the time of sending out the optical longitudinal message on the opposite side;

time for receiving longitudinal message on opposite side US₁' and opposite side entry interruption time US₄Is recorded as △ t₂，△t₂= US₁’－US₄；

Then, the synchronization difference △ t between the optical longitudinal messages of the side and the opposite side₁=（△t_n－△t_r）/2－△t₂；

By making the synchronization difference △ t₁Synchronization is achieved towards 0.

2. The low real-time optical longitudinal synchronization method of claim 1, wherein the sampling time of the local device is adjusted to make the synchronization difference △ t₁Tending towards 0.

3. The low real-time optical longitudinal synchronization method of claim 1, wherein: the device at the side and the device at the opposite side both adopt CPU chips special for electric power.

4. The low real-time optical longitudinal synchronization method of claim 3, wherein: the computer program implementing the method is cured on a power-specific CPU chip.

5. The low real-time optical longitudinal synchronization method of claim 4, wherein: the CPU chip special for electric power is a CPU chip with low dominant frequency.

6. The low real-time optical longitudinal synchronization method of claim 5, wherein: the main frequency of the CPU chip special for electric power does not exceed 800 MHz.

7. A CPU chip special for electric power is characterized in that: the power dedicated CPU chip, when executing the computer program, implements the steps of the method of any one of claims 1 to 2.

8. The power-dedicated CPU chip of claim 7, wherein: nanosecond counting of a CPU chip special for electric power is used as a synchronous reference.

Technical Field

The invention belongs to the field of sampling synchronization of relay protection of a power system, and relates to a CPU chip special for power and a low-real-time optical longitudinal synchronization method.

Background

The optical longitudinal protection is a main protection commonly used in relay protection, plays an important role in stable and reliable operation of a power grid, has higher requirements on real-time performance and synchronism of two sides of an optical fiber, and can meet the requirements on the quick action performance of the optical fiber protection and the requirements on the sensitivity, reliability and selectivity of the relay protection only under high real-time processing capacity. Because of the four requirements of relay protection, in the application of optical fiber protection, the real-time processing and the computing capability of a relay protection device have relatively high requirements, the dominant frequency of processor chips used by mainstream relay protection manufacturers at present is 800M or even higher, and the dominant frequency of chips dedicated for domestic electric power at present cannot be so high, so that the real-time response and the computing capability are limited.

Most of the existing synchronization methods for pilot differential protection are based on sampling value synchronization methods, mainly sampling time adjustment methods, which need to accurately record the sampling receiving time so as to adjust in a synchronization algorithm.

Disclosure of Invention

The invention aims to provide a low real-time optical longitudinal synchronization method based on a domestic electric power special CPU chip, which can solve the problem that optical longitudinal protection meets the four-characteristic requirement of relay protection in a low real-time processing environment after the domestic electric power special chip is used, and the angle difference of the opposite side relay protection device meets the action requirement of longitudinal differential motion.

The low real-time optical longitudinal synchronization method provided by the invention mainly solves the following problems:

(1) the use of the CPU chip dedicated to domestic power is limited in real-time response, including a scenario in which the interruption service program cannot be entered quickly and the interruption response is delayed by the program interrupted by other locks, so that in order to meet the quartering requirement of relay protection, the optical-longitudinal synchronization algorithm needs to be adjusted to adapt to the CPU chip dedicated to domestic power.

(2) The optical longitudinal synchronization algorithm is solidified into a CPU chip special for domestic electric power, the development of an optical longitudinal synchronization algorithm IP core is realized, and the execution efficiency is higher after solidification.

The technical scheme adopted by the invention is as follows:

a low real-time optical longitudinal synchronization method comprises the following steps:

the local side device receives the optical longitudinal message sent by the opposite side device, and the receiving time is CNT₁Representing the count of an internal 64-bit counter;

obtaining count CNT of local side internal 64-bit counter₂And microsecond time US₂A reference of (1);

calculating CNTs₂－CNT₁=CNT_xCorresponding microsecond time US_x；

Through reference, microsecond time when local side receives optical longitudinal message sent by opposite side is pushed backInter US₁＝US₂－US_x；

The time for sending the optical longitudinal message at the local side adopts the time US of entering interruption₃；

Abstracting the graph formed by connecting the sending and receiving time points of the optical longitudinal messages into an isosceles trapezoid, wherein the side length of the trapezoid at the side is △ t_r=US₃－US₁Side length △ t of trapezoid on opposite side_n= US₁’－US₃’，US₁' receiving longitudinal message time on opposite side, US₃' is the time of sending out the optical longitudinal message on the opposite side;

time for receiving longitudinal message on opposite side US₁' and opposite side entry interruption time US₄Is recorded as △ t₂，△t₂=US₁’－US₄；

Then, the synchronization difference △ t between the optical longitudinal messages of the side and the opposite side₁=（△t_n－△t_r）/2－△t₂；

By making the synchronization difference △ t₁Synchronization is achieved towards 0.

Further, the sampling timing of the local device is adjusted to make the synchronization difference △ t₁Tending towards 0.

Furthermore, the device on the side and the device on the opposite side both adopt CPU chips special for electric power.

Further, a computer program implementing the method is cured on a power-dedicated CPU chip.

Furthermore, the CPU chip special for electric power is a CPU chip with low main frequency.

Further, the main frequency of the CPU chip special for the electric power does not exceed 800 MHz.

A CPU chip dedicated to electric power, which implements the steps of any one of the above methods when executing a computer program.

Further, nanosecond counting of a CPU chip special for electric power is used as a reference for synchronization.

The method of the invention has the following characteristics and functions:

(1) the solidified ping-pong synchronization algorithm is more accurate in time scale and counter acquisition.

(2) The optimized datum point of the optical ping-pong synchronization algorithm can adapt to the low real-time performance of a chip special for domestic electric power so as to meet the four-characteristic requirement of relay protection.

The invention achieves the following beneficial effects:

the invention provides a low real-time optical longitudinal synchronization method based on a domestic electric power special CPU chip, which can solve the problem that after the domestic electric power special chip is used, under a low real-time processing environment, optical longitudinal protection reaches the four-characteristic requirement of relay protection, the angle difference of a side relay protection device meets the action requirement of longitudinal differential, the precision completely meets the synchronization requirement of an optical longitudinal protection algorithm, time which possibly causes jitter is eliminated, the precision is higher, and the longitudinal differential protection is more reliable.

Drawings

Fig. 1 is a schematic diagram of a time reference used in the optical ping-pong synchronization method in this embodiment.

Detailed Description

The following is a computational example of a synchronization process of the present invention, the features, objects and advantages of which will be apparent from the description of the embodiments.

In this embodiment, the local side device and the opposite side device are both domestic power dedicated CPU chips.

The method of the invention comprises the following steps:

(1) the device at the side receives the optical longitudinal message sent by the opposite side, and the receiving time is CNT₁Indicating the count of the internal 64-bit counter.

(2) In the optical longitudinal synchronization algorithm process, first, the count CNT of the internal 64-bit counter is obtained₂And microsecond time US₂The reference of (1).

(3) Calculating (CNT) according to the main frequency of the chip and other parameters₂－CNT₁）=CNT_xCorresponding microsecond time US_xThen push back by reference (US)₂－US_x）= US₁，US₁Representing the microsecond time of the side receiving the optical longitudinal message sent by the opposite side.

(4) The time for sending the optical longitudinal message at the local side adopts the time US of entering interruption₃The time of entering the interruption is more accurate, and the actual sending processing time in the interruption is calculated in the communication time instead of the actual sending time, so that the accuracy of the ping-pong algorithm reference time is ensured.

(5) The optical longitudinal synchronization algorithm is abstracted into an isosceles trapezoid, and the upper side length of the trapezoid at the side is △ t_r= US₃－US₁The upper side length of the trapezoid at the side refers to the time for processing the optical longitudinal message at the side, and the lower side length of the trapezoid at the opposite side is △ t_n= US₁’－US₃' the length of the lower side of the trapezoid on the opposite side refers to the total time from sending the optical longitudinal message to retrieving the optical longitudinal message of the same frame on the opposite side, including the communication time and the message processing time of the message back and forth. US₁' receiving longitudinal message time on opposite side, US₃' is the time for sending out the optical longitudinal message on the opposite side. Time for receiving longitudinal message on opposite side US₁' and opposite side entry interruption time US₄Time difference △ t₂= US₁’－US₄。

(6) Synchronization difference △ t₁=（△t_n－△t_r）/2－△t₂。

The above time is shown in fig. 1.

The ping-pong synchronization algorithm is abstracted into an isosceles trapezoid, the time of four corners of the isosceles trapezoid is determined during calculation, and the ping-pong synchronization principle is utilized to obtain the following synchronization difference of longitudinal and transverse lights of △ t₁=（△t_n－△t_r）/2－△t₂。

In this case, it is only necessary to adjust the sampling timing of the optical column device (i.e., the local device using the power-dedicated CPU chip) to adjust the synchronization difference △ t₁The synchronous process of the devices on the two sides of the optical longitudinal axis is finished as far as possible, and the reliability of longitudinal differential protection is ensured.

The method realizes the application of low real-time optical longitudinal protection on a domestic electric power special CPU chip with low dominant frequency. And curing the optical longitudinal synchronization algorithm on a domestic electric power special CPU chip with low main frequency.

The solidified optical ping-pong synchronization algorithm adopts the optimized reference time point.

In the solidified optical longitudinal synchronization algorithm, nanosecond counting of a domestic power special CPU chip is used as a reference of a subsequent synchronization algorithm.

The above description is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, several modifications and variations can be made without departing from the technical principle of the present invention, and these modifications and variations should also be regarded as the protection scope of the present invention.