CN103281148B - Without the need to the method for synchronizing network time that switch is supported especially - Google Patents

Abstract

The present invention relates to a kind of method for synchronizing network time supported especially without the need to switch, be applied to and comprise sampling unit, merge cells, in the protection and test system of functional unit, carry out synchronously to each clock in time standard signal injection merge cells, the method is applied in two scenes: when the deviate in (1) time standard signal and protection and test system between original markers is less than set point, by the base aerodynamic behaviour of computing relay time, dynamic corrections is arranged at the time delay jitter filter in protection and test system to merge cells, to realize time synchronized, (2), when the deviate in time standard signal and protection and test system between original markers is more than or equal to set point, merge cells adopts each clock of optimized algorithm tracking adjustment to realize time synchronized.Method of the present invention realizes the precise synchronization under the functional restraint that protection and test system is suitable for, and provides special hardware supports without the need to the networking network equipment, efficient, flexibly.

Description

A network time synchronization method that does not require special support from switches

technical field

The invention relates to a network time synchronization method adopted in a substation protection and measurement and control system.

Background technique

The precise time protocol suitable for substation measurement and control systems provides networked protection and measurement and control systems with time synchronization performance that may meet the functional requirements, but the protocol does not have a specially specified tracking and adjustment algorithm, and requires networked devices to have hardware-level time Identification support, so it sets technical and cost constraints for its wide application in substation protection and measurement and control systems.

The main methods to solve the time synchronization of the protection and measurement and control system are:

1. Network time message broadcast

In the system, a device that accepts external time standard injection is designated to be calibrated according to the external time standard, and broadcast messages are issued on the network at specified time intervals, and other devices in the system are aligned with the time according to this time message to achieve synchronization. Due to the influence of network transmission message delay and time synchronization performance of each device, this method can only obtain time synchronization with low precision. It has some applications in conventional small-scale and low-voltage level measurement and control systems.

2. Establish a set of time synchronization system, add synchronization pulse to time message

Establish a time synchronization system, use network messages or inject specific devices in the protection and measurement and control system, and then release time from this device as the system, and connect synchronization pulses to each device with cables or optical fiber cables, and release synchronization pulses according to fixed rules. Each device performs tracking synchronization. This method is commonly used in protection and measurement and control systems of various voltage levels. It can achieve better time synchronization, but it requires a more complicated time synchronization system and a large number of connecting cables, and it requires more time to use this method in a distributed sampling value network. High time synchronization performance and more connecting cables.

Third, the use of precise time protocol

The application of the precise time protocol in the protection and measurement system can achieve a high level of time synchronization, but the implementation of this protocol has requirements for system hardware and software, and it needs to be specially customized for the distributed sampling value network protection and measurement and control system.

Contents of the invention

The purpose of the present invention is to provide a network time synchronization method with high precision and good synchronization without special support of the switch to meet the functional requirements of the substation protection and measurement and control system.

In order to achieve the above object, the technical scheme adopted in the present invention is:

A network time synchronization method that does not require special support from a switch, and is applied to a substation protection and measurement and control system. The substation protection and measurement and control system includes a sampling unit that follows the grid cycle for sampling, and is connected to the sampling device and transmits the sampling A data merging unit, a functional unit that is connected to the merging unit and receives the sampled data to realize corresponding functions, and the time standard signal is injected into the merging unit and is transmitted to the substation through the merging unit The clocks in the protection and measurement and control system are synchronized. The network time synchronization method without the special support of the switch is applied in two scenarios. The two scenarios are: (1) The time standard signal and the When the deviation value between the original time scale in the substation protection and measurement and control system is less than the set value; (2) The deviation between the time standard signal and the original time scale in the substation protection and measurement and control system When the value is greater than or equal to the stated set value;

When the deviation between the time standard signal and the original time scale in the substation protection and measurement and control system is less than the set value, the merging unit dynamically corrects the setting at the time scale by calculating the bottom characteristic of the delay time The time delay jitter filter in the substation protection and measurement and control system described above is used to filter unilateral vibration through the time delay jitter filter to realize the time synchronization of each clock in the substation protection and measurement and control system;

When the deviation between the time standard signal and the original time scale in the substation protection and measurement and control system is greater than or equal to the set value, the merging unit uses an optimization algorithm to track and adjust the Clocks in substation protection and measurement and control systems to achieve time synchronization.

In the above solution, the substation protection and measurement and control system adopts distributed sampling value networking.

The merging unit receives the time standard signal, calculates the deviation value between the time standard signal and the original time scale in the substation protection and measurement and control system, and compares the deviation value with the the settings described above.

When the deviation between the time standard signal and the original time scale in the substation protection and measurement and control system is less than the set value, the merging unit uses the unilateral finite characteristic of the delay time to calculate the The bottom characteristic of the delay time described.

When the deviation between the time standard signal and the original time scale in the substation protection and measurement and control system is less than the set value, the network time synchronization method without special support of the switch includes the following steps: (1 ) The merging unit establishes a time traceable mark, and responds to the time delay test, and the clock of the merging unit is calibrated and adjusted according to the time delay parameter; (2) The merging unit is calibrated according to the time delay parameter; The bottom characteristic of the delay time obtained from the above time delay test, and use the time delay jitter filter to filter unilateral vibration, so as to realize time synchronization.

The time standard signal is injected into the merging unit through the network port of the switch.

Due to the use of the above-mentioned technical solutions, the present invention has the following advantages compared with the prior art: the network time synchronization method provided by the present invention does not require special support from switches, and realizes high-precision time synchronization under the functional constraints applicable to protection and measurement and control systems, and does not require Network equipment for networking provides specialized hardware support, featuring high efficiency and flexibility.

Detailed ways

The present invention will be further described below in conjunction with embodiment.

Embodiment 1: A method for synchronizing network time without special support from switches, which is applied to a substation protection and measurement and control system using distributed sampling values. The substation protection and measurement and control system includes a sampling unit that follows the grid cycle for sampling, a merging unit that is connected to the sampling device and transmits the sampled data, and a functional unit that is connected to the merging unit and receives the sampled data to realize corresponding functions.

The time standard signal is injected into the merging unit through the network port of the switch, and the clocks in the substation protection and measurement and control system are synchronized through the merging unit. Specifically, the network time synchronization method without the special support of the switch is applied in two scenarios. The two scenarios are: (1) The deviation between the time standard signal and the original time scale in the substation protection and measurement and control system is less than the set value (2) When the deviation between the time standard signal and the original time scale in the substation protection and measurement and control system is greater than or equal to the set value.

The merging unit receives the time standard signal, calculates the deviation value between the time standard signal and the original time scale in the substation protection and measurement and control system, and compares the deviation value with the set value.

When the deviation between the time standard signal and the original time scale in the substation protection and measurement and control system is less than the set value, the merging unit uses the unilateral finite characteristic of the delay time to calculate the bottom characteristic of the delay time, and then dynamically corrects the settings in the substation The time delay jitter filter in the protection and measurement and control system filters unilateral vibration through the time delay jitter filter to realize the time synchronization of each clock in the substation protection and measurement and control system.

At this time, the following steps are included: (1) The merging unit establishes a time traceable flag and responds to the time delay test. The clock of the merging unit follows the time standard message on the network, and performs calibration and adjustment according to the obtained time delay parameters; (2) According to the bottom characteristics of the delay time obtained from the time delay test under different load intensities, the merging unit uses a time delay jitter filter to filter unilateral vibration to achieve time synchronization.

And when the deviation value between the time standard signal and the original time scale in the substation protection and measurement and control system is greater than or equal to the set value, the homing time can track the mark, and the merging unit uses the optimization algorithm to track and adjust the substation protection and measurement and control system. Clocks for time synchronization.

The above method can not only provide support for the substation protection and measurement and control system application functions of distributed sampling value groups, but also provide a method for obtaining time synchronization for other distributed network data acquisition systems, and does not require special hardware support for switches. Realize the modularization of functions and have good portability. This method integrates research, processing and integration of existing methods to realize time synchronization that meets the needs of substation protection and measurement and control systems in network hardware and software systems under the constraints of non-special technical performance, and has wide adaptability to the network for transmitting data.

The above-mentioned embodiments are only to illustrate the technical concept and characteristics of the present invention, and the purpose is to enable those skilled in the art to understand the content of the present invention and implement it accordingly, and not to limit the protection scope of the present invention. All equivalent changes or modifications made according to the spirit of the present invention shall fall within the protection scope of the present invention.

Claims (4)

1. the method for synchronizing network time supported especially without the need to switch, be applied in transforming plant protecting and TT&C system, described transforming plant protecting and TT&C system comprise the sampling unit of following grid cyclic wave and carrying out sampling, be connected with described sample devices and transmit the merge cells of sampled data, be connected with described merge cells and sampled data described in receiving to realize the functional unit of corresponding function, it is characterized in that: carry out synchronous to described transforming plant protecting with each clock in TT&C system by described merge cells in the merge cells described in time standard signal injection, the described method for synchronizing network time supported especially without the need to switch is applied in two scenes, scene described in two is respectively: when the deviate in the time standard signal described in (1) and described transforming plant protecting and TT&C system between original markers is less than set point, (2) when the deviate in the time standard signal described in and described transforming plant protecting and TT&C system between original markers is more than or equal to described set point,

When the deviate in described time standard signal and described transforming plant protecting and TT&C system between original markers is less than set point, described merge cells utilizes the monolateral finite nature of time of delay and the base aerodynamic behaviour of computing relay time, and then dynamic corrections is arranged at the time delay jitter filter in described transforming plant protecting and TT&C system, monolateral vibration is filtered, to realize the time synchronized of each clock in described transforming plant protecting and TT&C system by described time delay jitter filter; Now comprise the steps: that the merge cells described in (1) can follow the tracks of mark settling time, and make the response of AT speed test, the clock of described merge cells carries out calibration adjustments according to the parameter of described time delay; (2) merge cells described in, according to the base aerodynamic behaviour of the described time of delay of described AT speed test gained, uses described time delay jitter filter to filter monolateral vibration, to realize time synchronized;

When the deviate in described time standard signal and described transforming plant protecting and TT&C system between original markers is more than or equal to described set point, described merge cells adopts the transforming plant protecting described in optimized algorithm tracking adjustment and each clock in TT&C system to realize time synchronized.

2. the method for synchronizing network time supported especially without the need to switch according to claim 1, is characterized in that: described transforming plant protecting and TT&C system adopt the networking of distributed sample value.

3. the method for synchronizing network time supported especially without the need to switch according to claim 1; it is characterized in that: the time standard signal described in described merge cells receives; deviate in time standard signal described in calculating and described transforming plant protecting and TT&C system between original markers, and deviate described in comparison and described set point.

4. the method for synchronizing network time supported especially without the need to switch according to claim 1, is characterized in that: the merge cells described in described time standard signal is injected by the port of switch.