Сучасні протоколи передачі шкали часу інтелектуальних електроенергетичних систем зі зниженою аварійністю

Анотація

UDC 681.516.75:631.234

TIME-SCALE DISTRIBUTION MODERN PROTOCOLS FOR SMART GRID POWER SYSTEMS WITH LOW ACCIDENT RATE

O. Velychko, V. Koval, O. Samkov, I. Shkliarevskyi

In the last about 10 years , in different counties the reasons for power failures or blackouts in which more than one power utility is involved must be analyzed. The so-called cascading emergency power outages, which entail serious social consequences (emergency stops of trains in underground tunnels, trams and trolleybuses streets, elevators in high-rise buildings, disconnect from the electric power electrical devices, hospitals, kindergartens , enterprises with continuous production, etc.) have appeared for the general public. Examples of  some power outgates are shown in the Table 1.

Table 1.

Year	Country or region	Involved population , millions
2003	USA, Canada	55
2003	Italy	56
2005	Indonesia	100
2005	Russia	3
2011	USA, Mexico	5
2012	India	620

The North American Blackout back in August 2003 visualized how painful and time consuming it can be to align data, whose time stamps are derived from inaccurate time references. As a result the task force investigating the blackout demanded a regulation that ensures a minimum absolute accuracy for time stamped disturbance event data.

Analysis of cascading outages of electricity, which recently took place in the world [1],[2] can show, in addition to the purely technical, the presence of other, more common causes of such events. First of all, it's deregulation of the electricity market, making this market extremely highly, but less manageable. In order to prevent undesirable consequences specified problematic situation in the energy sector developed the concept of intellectual power grid (Smart Grid), which is an important part of that is associated with continuous monitoring of grid stability parameters linked to real-time with microsecond precision.

In Ukraine there is a public service Time and Frequencies Reference for coordination and implementation of activities aimed ensuring the uniformity of time and frequency measurements, creating and maintaining a national time-scale confirmed to the best national scales the world. But Ukraine's existing time and frequency distribution technical means and methods do not form a single system and can not meet the requirements of all customers time-frequency information that encourages them to use synchro-information from other states’ sources (GPS or GLONASS), which threatens the national security and increases the risks of loss of traceability time and frequency within the state. Implementation of the Precision Time Protocol (PTP), defined in the IEEE 1588 standard provides a very accurate and safe way to distribute time references throughout the power station’s Ethernet networks. PTP allows distributing reference time information in a local area network like NTP does, but due to the innovative protocol it allows to reach accuracies in the sub-microsecond range.

There’s a PTP supporting equipment named SU-1588, developed and manufactured in Ukraine, which provides the necessary services distributing the national time-scale from the Secondary Time and Frequency Reference located in Ukrmetrteststandart enterprise in Kiev. The direct connection 30 minutes interval stability between different manufacturers’ equipment was tested in [4]. Table 2 shows some results from [4] combining with some SU-1588 results  provided by it’s manufacturer. 

Table 2.

Slave/ Master	Slave A	Slave B	Slave C	Slave F	SU-1588S (slave)	Information source
Master A	-	705	304	798	-	[4]
Master C	715	156	-	43	-	[4]
Master D	670	255	232	200	-	[4]
OSA-5535	-	-	-	-	320	IST Ltd
SU-1588M	-	-	-	-	250	IST Ltd

Conclusion

A modern power field needs precise time-stamping for new monitoring and measurement methods for Smart Grid’s implementation. The SU-1588 equipment supporting “power” profile of IEEE 1588 protocol, is able to provide time-scale microseconds level distribution for power industry.