CN112803361A - Method and device for checking consistency of receiving and transmitting delays of optical fiber differential protection channel on line - Google Patents

Abstract

The invention relates to a method and device for online checking the consistency of transmission and reception delay of optical fiber differential protection channel. The channel delay is calculated separately from the sending time and the time when the message is received, and the consistency check is performed on the separately calculated channel delay, so that it is possible to clearly compare whether the channel sending and receiving delays of the devices on both sides are consistent, and based on The check result can know whether to open or close the differential protection, which solves the problem of reducing the reliability of the line differential protection when the transmission and reception delays of the two sides of the optical fiber longitudinal channel of the line protection device are inconsistent, and avoids the transmission and reception of the channel in the event of an out-of-area fault. The risk of protection misoperation caused by inconsistent delays provides a real-time monitoring method for channel transmission and reception delay consistency, and improves the reliability of data synchronization on both sides of the channel, thereby ensuring the performance of differential protection.

Description

Method and device for online checking of transmission and reception delay consistency of optical fiber differential protection channel

technical field

The invention relates to the technical field of power system relay protection, in particular to a method and a device for online checking the consistency of transmission and reception delays of optical fiber differential protection channels.

Background technique

The relay protection signal should meet the requirements of reliability, selectivity, sensitivity and quickness. The action time of the relay protection is directly related to the safety of the power grid. Therefore, the optical fiber differential protection of the line protection device requires the transmission delay of the channel. Very strict. In the optical fiber longitudinal channel of the line protection devices on both sides, the delays generated by each link are inconsistent, resulting in inconsistent sending and receiving delays of the longitudinal channels on both sides, which seriously affects the reliability of sampling data synchronization and differential protection.

In addition, the synchronization adjustment of the fiber channel in the existing line protection device is performed based on the consistent channel transmission and reception delay and stable channel delay. When the transmission and reception delays of the channels on both sides are inconsistent, the data synchronization on both sides of the line and the calculation of the differential current of the differential protection will be affected, and there is a risk of protection misoperation and reliability.

On-line checking and calculating the consistency of transmit and receive delays of optical fiber differential protection channels is a technical problem to be solved urgently in this field.

SUMMARY OF THE INVENTION

Based on the above-mentioned situation of the prior art, the purpose of the present invention is to provide a method for online checking and calculating the consistency of transmission and reception delays of optical fiber differential protection channels, so as to solve the problem of inconsistent transmission and reception delays of channels on both sides of the optical fiber longitudinal channel of the line protection device. The problem of reducing the reliability of the line differential protection is caused.

In order to achieve the above object, according to one aspect of the present invention, there is provided a method for online checking the consistency of transmission and reception delay of optical fiber differential protection channel, comprising the steps of:

sending a first message to the opposite end of the channel, where the first message includes the current sending time value T _s1 ;

Receive the second packet sent by the opposite end, where the second packet includes a time value T _s2 for sending the second packet and a first delay T _delta1 , where the first delay T _delta1 is determined by the pair The side terminal is calculated according to T _s1 and the time value T _d1 at which it receives the first message;

Calculate the second delay T _delta2 according to the reception time T _d2 of receiving the second message and the time value T _s2 when the peer end of the channel sends the second message;

Calculate the delay difference ΔT _d according to the first delay T _delta1 and the second delay T _delta2 :

ΔT _d =|T _delta2 -T _delta1 |

It is judged whether ΔT _d is greater than the preset threshold value T _mk , if T _d is greater than T _mk , the differential protection is blocked and an alarm signal is sent; if T _d is less than or equal to T _mk , the differential protection is opened.

Further, calculating T _delta1 according to T _s1 and T _d1 , including calculating T _delta1 according to the following formula:

T _delta1 =T _d1 -T _s1 .

Further, calculating T _delta2 according to T _s2 and T _d2 includes calculating T _delta2 according to the following formula:

T _delta2 =T _d2 -T _s2 .

Further, before sending the first message, it also includes steps:

Determine whether the current time is a whole second, if so, clear the timer and send the message; if not, increase the timer by one unit, and perform this step again.

Further, before judging whether ΔT _d is greater than the preset threshold value T _mk , the steps further include:

Send and receive messages multiple times to calculate T _delta1 and T _delta2 , obtain the average value of T _delta1 and T _delta2 respectively, and use the average value of T _delta1 and T _delta2 to calculate ΔT _d .

According to a second aspect of the present invention, there is provided a device for online checking the transmission and reception delay consistency of an optical fiber differential protection channel, including a sending module, a receiving module, and a main protection module; wherein

The sending module sends a first message to the opposite end of the channel, where the first message includes the current sending time value T _s1 ;

The receiving module receives a second message sent by the opposite end, where the second message includes a time value T _s2 for sending the second message and a first delay T _delta1 ;

The main protection module is connected to the sending module and the receiving module respectively, and calculates the second message according to the receiving time T _d2 of receiving the second message and the time value T _s2 when the opposite end of the channel sends the second message. delay T _delta2 ; and,

Calculate the delay difference ΔT _d according to the first delay T _delta1 and the second delay T _delta2 :

ΔT _d =T _delta2 -T _delta1

And according to the judgment result of whether ΔT _d is greater than the preset threshold value T _mk , block or open differential protection is performed.

Further, it also includes a counter module;

The counter module judges whether the current time is a whole second, and if so, clears the timing and starts the sending module and the receiving module; if not, increments the timing by one unit and re-judges.

Further, the main protection module executes the blocking or opening of the differential protection according to the judgment result of whether ΔT _d is greater than the preset threshold value T _mk , including: if T _d is greater than T _mk , blocking the differential protection and sending an alarm signal; If T _d is less than or equal to T _mk , the differential protection is opened.

According to a third aspect of the present invention, an optical fiber differential protection channel system is provided, including an optical fiber differential protection channel and at least two optical fiber differential line protection devices; wherein,

The at least two optical fiber differential line protection devices are arranged on both sides of the optical fiber differential protection channel, and each optical fiber differential line protection device includes the online calibration optical fiber difference according to the second aspect of the present invention. A device that automatically protects the channel sending and receiving delay consistency.

To sum up, the present invention provides a method and device for online checking the consistency of transmission and reception delays of optical fiber differential protection channels. The channel delay is calculated according to the sending time and the time when the message is received, and the consistency check is performed on the separately calculated channel delay, so that the channel sending and receiving delays of the devices on both sides can be clearly compared. Whether the time is consistent, and according to the check result, it can be known whether to open or close the differential protection, which solves the problem of reducing the reliability of the line differential protection when the transmission and reception delays of the two sides of the optical fiber longitudinal channel of the line protection device are inconsistent. The risk of protection misoperation caused by inconsistent channel sending and receiving delays during out-of-area faults provides a real-time monitoring method for channel sending and receiving delay consistency, and improves the reliability of data synchronization on both sides of the channel, thereby ensuring the performance of differential protection. .

Description of drawings

Fig. 1 is the flow chart of the present invention's online check optical fiber differential protection channel sending and receiving delay consistency method;

2 is a schematic diagram of the method for online checking the transmission and reception delay consistency of an optical fiber differential protection channel according to the present invention;

FIG. 3 is a block diagram of the structure of the device for online checking the transmission and reception delay consistency of the optical fiber differential protection channel according to the present invention.

Detailed ways

In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the specific embodiments and the accompanying drawings. It should be understood that these descriptions are exemplary only and are not intended to limit the scope of the invention. Also, in the following description, descriptions of well-known structures and techniques are omitted to avoid unnecessarily obscuring the concepts of the present invention.

The technical solutions of the present invention will be described in detail below with reference to the accompanying drawings. According to an embodiment of the present invention, an online method for checking the transmission and reception delay consistency of an optical fiber differential protection channel is provided. The flowchart of the method is shown in FIG. 1 . Corresponding modules in any one of the devices are implemented, and the method includes the steps of:

First, determine whether the current time is a whole second. If so, clear the timer and send the message; if not, increase the timer by one unit and perform this step again.

Send a first packet to the opposite end of the channel, where the first packet includes the current sending time value T _s1 .

Receive the second packet sent by the opposite end, where the second packet includes a time value T _s2 for sending the second packet and a first delay T _delta1 , where the first delay T _delta1 is determined by the pair The side terminal is calculated according to T _s1 and the time value T _d1 at which it receives the first packet, and T _delta1 can be calculated according to the following formula:

T _delta1 =T _d1 -T _s1 .

The second delay T _delta2 is calculated according to the receiving time T _d2 of receiving the second packet and the time value T _s2 when the peer end of the channel sends the second packet, and T _delta2 can be calculated according to the following formula:

T _delta2 =T _d2 -T _s2 .

Calculate the delay difference ΔT _d according to the first delay T _delta1 and the second delay T _delta2 :

ΔT _d = |T _delta2 −T _delta1 |.

In order to obtain a more accurate result, T _{delta1 and T delta2 can be calculated by sending and receiving the message multiple times, and the average value of T delta1 and} T _{delta2 can} be obtained respectively, and the average value can be converted into the actual amount of time, Thereby, the one-way transmission delay of the channel is obtained, and packet transmission is performed to calculate ΔT _d by using the average value.

It is judged whether ΔT _d is greater than the preset threshold value T _mk , if T _d is greater than T _mk , the differential protection is blocked and an alarm signal is sent; if T _d is less than or equal to T _mk , the differential protection is opened. T _mk can be set according to the actual needs of the relay protection system, for example, it is set to 0.1ms.

The schematic diagram of this method is shown in Figure 2, S represents the timeline of the sender, D represents the timeline of the receiver, and the sender calculates the sender's delay T _delta1, T according to the sending time and the receiving time in the message of the receiver. _delta2 ... T _delta .

According to the second embodiment of the present invention, an online device for checking the consistency of sending and receiving delays of optical fiber differential protection channels is provided. The block diagram of the device is shown in FIG. 3 , and the device includes a counter module, a sending module, a receiving module, and the main protection module. This module can be installed on both sides of the optical fiber differential protection channel. In order to ensure accurate calculation results, the devices on both sides of the line use the same time synchronization method. For example, FPGA decoding can be used to generate the second reference as the time reference of the devices on both sides. At the same time, the devices on both sides maintain an internal counter locally, and the counter is cleared based on the seconds generated by the time-synchronization decoding. The devices on both sides do not need to be replaced, and there is no need to provide additional devices to calculate the delay difference between the transmission and reception of the pilot channel.

The counter module judges whether the current time is a whole second, if so, clears the timing and starts the sending module and the receiving module; if not, increases the timing by one unit and re-judgments. That is to say, after detecting the second reference, the local device sends a special message frame including a time value at the whole second.

The sending module, after detecting the second reference, sends a first message to the opposite end of the channel, where the first message includes the current sending time value T _s1 . When the receiving module on the opposite side receives the first message, the main protection module on the opposite side calculates the second delay T _delta1 according to the current receiving time T _d1 , and encapsulates it together with the sending time T _s2 of the second message in the second message.

The receiving module receives a second packet sent by the opposite end, where the second packet includes a time value T _s2 for sending the second packet and a first delay T _delta1 .

The main protection module is respectively connected with the sending module and the receiving module, and calculates the second delay according to the receiving time T _d2 for receiving the second message and the time value T _s2 when the opposite end of the channel sends the second message T _delta2 ; and,

Calculate the delay difference ΔT _d according to the first delay T _delta1 and the second delay T _delta2 :

ΔT _d =T _delta2 -T _delta1

And according to the judgment result of whether ΔT _d is greater than the preset threshold value T _mk , the differential protection is blocked or opened. Specifically, if T _d is greater than T _mk , the differential protection is blocked and an alarm signal is issued; if T _d is less than or equal to T _mk , the differential protection is opened.

According to a third embodiment of the present invention, an optical fiber differential protection channel system is provided, including an optical fiber differential protection channel and at least two optical fiber differential line protection devices. Wherein, the at least two optical fiber differential line protection devices are arranged on both sides of the optical fiber differential protection channel, and each optical fiber differential line protection device includes the online calibration device according to the second embodiment of the present invention. A device for transmitting and receiving delay consistency of a nuclear optical fiber differential protection channel is used for realizing the consistency verification of the optical fiber differential protection channel delay.

To sum up, the present invention relates to a method and device for online checking the consistency of transmission and reception delays of optical fiber differential protection channels. The channel delay is calculated according to the sending time and the time when the message is received, and the consistency check is performed on the separately calculated channel delay, so that the channel sending and receiving delays of the devices on both sides can be clearly compared. Whether it is consistent, and whether to open or close the differential protection according to the check result, solves the problem of reducing the reliability of the differential protection of the line when the transmission and reception delays of the two sides of the optical fiber longitudinal channel of the line protection device are inconsistent, and avoids the problem of The risk of protection misoperation caused by inconsistent channel transmission and reception delays during external faults provides a real-time monitoring method for channel transmission and reception delay consistency, and improves the reliability of data synchronization on both sides of the channel, thereby ensuring the performance of differential protection.

It should be understood that the above-mentioned specific embodiments of the present invention are only used to illustrate or explain the principle of the present invention, but not to limit the present invention. Therefore, any modifications, equivalent replacements, improvements, etc. made without departing from the spirit and scope of the present invention should be included within the protection scope of the present invention. Furthermore, the appended claims of the present invention are intended to cover all changes and modifications that fall within the scope and boundaries of the appended claims, or the equivalents of such scope and boundaries.

Claims (9)

1. a method for online checking optical fiber differential protection channel transceiver delay consistency, is characterized in that, comprises the steps: sending a first message to the opposite end of the channel, where the first message includes the current sending time value T _s1 ; Receive the second packet sent by the opposite end, where the second packet includes a time value T _s2 for sending the second packet and a first delay T _delta1 , where the first delay T _delta1 is determined by the pair The side terminal is calculated according to T _s1 and the time value T _d1 at which it receives the first message; Calculate the second delay T _delta2 according to the reception time T _d2 of receiving the second message and the time value T _s2 when the peer end of the channel sends the second message; Calculate the delay difference ΔT _d according to the first delay T _delta1 and the second delay T _delta2 : ΔT _d =|T _delta2 -T _delta1 | It is judged whether ΔT _d is greater than the preset threshold value T _mk , if T _d is greater than T _mk , the differential protection is blocked and an alarm signal is sent; if T _d is less than or equal to T _mk , the differential protection is opened. 2. The method according to claim 1, wherein calculating T _delta1 according to T _s1 and T _d1 , comprising calculating and obtaining T _delta1 according to the following formula: T _delta1 =T _d1 -T _s1 . 3. The method according to claim 1, wherein calculating T _delta2 according to T _s2 and T _d2 , comprising calculating and obtaining T _delta2 according to the following formula: T _delta2 =T _d2 -T _s2 . 4. The method according to claim 2 or 3, characterized in that, before sending the first message, it also comprises the steps: Determine whether the current time is a whole second, if so, clear the timer and send the message; if not, increase the timer by one unit, and perform this step again. 5. The method according to claim 4, wherein before judging whether ΔT _d is greater than the preset threshold value T _mk , the method further comprises the steps of: Send and receive messages multiple times to calculate T _delta1 and T _delta2 , obtain the average value of T _delta1 and T _delta2 respectively, and use the average value of T _delta1 and T _delta2 to calculate ΔT _d . 6. A device for online checking the consistency of transmission and reception delays of optical fiber differential protection channels, characterized in that it comprises a sending module, a receiving module, and a main protection module; wherein The sending module sends a first message to the opposite end of the channel, where the first message includes the current sending time value T _s1 ; The receiving module receives a second message sent by the opposite end, where the second message includes a time value T _s2 for sending the second message and a first delay T _delta1 ; The main protection module is connected to the sending module and the receiving module respectively, and calculates the second message according to the receiving time T _d2 of receiving the second message and the time value T _s2 when the opposite end of the channel sends the second message. delay T _delta2 ; and, Calculate the delay difference ΔT _d according to the first delay T _delta1 and the second delay T _delta2 : ΔT _d =T _delta2 -T _delta1 And according to the judgment result of whether ΔT _d is greater than the preset threshold value T _mk , block or open differential protection is performed. 7. The device of claim 6, further comprising a counter module; The counter module judges whether the current time is a whole second, and if so, clears the timing and starts the sending module and the receiving module; if not, increments the timing by one unit and re-judges. 8. The device according to claim 7, wherein the main protection module performs blocking or opening differential protection according to the judgment result of whether ΔT _d is greater than the preset threshold value T _mk , including: if T _d is greater than T _mk , the differential protection is blocked and an alarm signal is sent; if T _d is less than or equal to T _mk , the differential protection is opened. 9. An optical fiber differential protection channel system, characterized in that it comprises an optical fiber differential protection channel and at least two optical fiber differential line protection devices; wherein, The at least two optical fiber differential line protection devices are arranged on both sides of the optical fiber differential protection channel, and each optical fiber differential line protection device includes the online check according to any one of claims 6-8. A device for transmitting and receiving delay consistency of optical fiber differential protection channels.

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