Bueno Electric's GPS Sync Clock
1. Overview
Grid dispatching integrated automation system of SCADA function for the dispatcher, set each substation controller provides real-time data and information, and can make them easy to repeat or accident history data and information query. In system design, the need to consider more is network structure, communication protocol conversion, data storage medium and satisfy the requirement of the SCADA function several performance indexes, without taking into account the system so what is the impact of the clock is not synchronized. Because the system so the clock out of sync will cause some of the more special fault, such as data and information loss, SOE event information logic chaos, some workstation crash even system paralysis, so in order to eliminate the influence of the clock out of sync, it is necessary to analyze the clock synchronization in the system and the realization of a variety of ways.
The strong power grid dispatching integrated automation system is a real-time system, it gathers each substation real-time data and information, after processing of the system software on the workstation according to relevant data and information, or stored in the historical database. The dispatching station integrated automation system is divided into factory end system and end system, the main implementation tech-oriented clock synchronization by three parts:
(1) The main end system each workstation with the primary server pair;
(2) Substation end system master control unit with the master station system pair;
(3) Substation end system master control unit and the unit interval intelligent pair.
2. Master station synchronization
The master station, with the purpose of the master server pair is to ensure that data such as add, change, delete operation consistency and completeness of the entire network. Inconsistencies and incomplete data will cause the main case system switch or historical data for storage, can not correctly identify the data consistency and integrity, resulting in the loss of information and data, even lead to paralysis of the system. Due to various workstations and servers crystals chip for a long time after the operation, there will be a clock no problem due to leakage or other reasons, and take the corresponding pair way to realize the main end system network pairs, as shown in figure 1, figure 2 ways:
Main end systems generally do not adopt the way of figure 1 pair way, because the GPS time server only provides a network interface, the other in order to achieve and GPS time setting, all the servers, workstations and front machine need to run the pair process, thereby waste of system resources. Figure 2 pair method, the front machine operation process for fashion pair with the GPS time server, on a regular basis and on a regular basis for servers and network devices, such as radio pair command, which can conveniently realize the pair in the system, thus the main end system usually adopt the way of figure 2 pair way. Data written history library or report timing print is often done in the hour, such as systematic pair at this time will be because of time inconsistency, and cause the loss of data or system failure. Based on this reason, the pair cycle (unit: minutes) should not be divisible number of 60, such as 2, 3, 4, 5 pair cycle also cannot too long, so we suggest using a system pair every 7 minutes. Operation shows that the pair cycle can meet the needs of the system normal operation.
3. Substation terminal synchronization.
GeChang station end system master control unit with the master station system prevailed, and GeChang station end system master control unit, with the purpose of the pair in each interval intelligence unit is to ensure that the data can be gathered by the interval of intelligent information, in the master station system after processing, can correct the time of the repeat data or information, order and logical relations. The dispatcher, set controller according to the display of data and information, a real-time control power system operation state, thus ensuring economic dispatch, security scheduling.
Some of the unattended substation factory end system equipped with GPS time server, and therefore do not need to pair with the master station system. Not installed GPS time server side of the system, through the main terminal pair frontend radio command for fashion, due to the need for data processing, so the pair cycle can be set for a long time, such as 30 minutes. Equipped with GPS time server end system and each interval of the intelligent unit ways pair as shown in figure 3, figure 4 ways:
Bueno Electric's GPS clock is designed for the synchronization of SCADA system, for more product details, please see the product page: http://www.bueno-electric.com/products/gps-clocks-and-time-severs/gps-ntp-time-server.html