Introduction
Today's power industry faces many challenges due to the increasing demand for energy, the need for efficient energy use and the integration of renewable sources. The integration process can be effectively realised through solutions based on those defined in the IEC 61850 set of standards. The key solutions are based on digital sampling methods, where precise time synchronisation is an indispensable element. Its accuracy determines the quality and reliability of measurement data and is extremely important. At substations, it is usually acquired via Global Navigation Satellite System (GNSS) synchronisation systems and transported via protocols such as IEEE 1588 PTPv2. It is extremely important to design the acquisition of precision time and its transport in such a way that these processes are as controllable and reliable as possible.
BITSTREAM S.A. - leader in time synchronisation technology for the energy industry
For 18 years, BitStream has been providing reliable solutions to Polish and international energy companies. As an industry leader, we offer innovative devices that improve connectivity, communication and management in the energy sector. To date, we have successfully completed more than 1,000 implementations, covering the management of substations, energy companies and distributed energy resources.
Our solutions support key processes in the power industry, enabling real-time monitoring and management of networks. We work with market leaders to deliver technologies that set new standards in the industry.
Precise time synchronisation as the foundation for reliability
Real-time digital sampling solutions, such as Phasor Measurement Units (PMUs) or Sampled Values (SVs), require time synchronisation with micro- or nanosecond accuracy. The digital sampling of PMUs and SVs is designed to allow area-based monitoring of dynamic processes, enabling rapid response to overloads, transients or even prediction of equipment failures. In addition, the format of the data and its tagging very well allows the use of machine learning methods with supervision or graph-based methods to control the network.
There is one key prerequisite for achieving the intended tasks and that is precise time synchronisation at sub-microsecond levels. It should be mentioned that its accuracy is an important factor in being able to use the data in the most efficient way. It is no less important that the difference in synchronisation accuracy between devices is also no greater than a few hundred nanoseconds, as this will be the main factor determining the suitability of the data for analysis. Therefore, it is reasonable and strongly recommended to obtain it from a central source and transport it using developed network protocols and dedicated devices. An example of a solution used in such cases is IEEE 1588 PTPv2. The power industry's implementation of the PTP v.2 protocol, referred to as the Power Profile and Utility Profile, carries a number of specific protocol features required in its generation in time sources as well as in transport. BITSTREAM solutions from the HYPERION-500 and QUAZAR-700 time servers to the HYPERION 402 process bus network switches support the full range of IEC61850 normative requirements for supported PTP v.2 implementations and are tested for interoperability with most leading manufacturers' substation solutions.
GNSS technologies as a reliable time source
It was traditionally accepted to refer to positioning and timing systems as GPS systems, which was associated with the first and, in some ways, most popular time and position system, the Global Positioning System. This was followed by GPS and Glonass (Russian System) receivers. Developments in technology and the geopolitical situation and associated attacks on the GPS radio signal have created a condition where the implementation of receivers based on a single GPS system is highly risky. In the world of extracting atomic time from radio signals, we have a situation where, in addition to GPS, there are now systems such as Gallileo (the European and Only Civil Positioning and Time System), Beidou, QZSS. In addition, for each of these, there appears to be transmission carried out on different frequency bands simultaneously (Fig.1), which makes signal interference through Jamming and Spoofing methods much more difficult.
Fig. 1. Available GNSS radio signal systems and bands
Therefore, if we use state-of-the-art precision time acquisition devices such as Primary Reference Timing Clocks (PRTCs), we can easily manage risk and increase the system's resilience to attacks.
GNSS receivers such as these are built into BITSTREAM devices such as the HYPERION-500 and QUAZAR-700. By being able to use signals from available systems and diversifying the frequency bands for the primary and backup clocks, we can significantly increase the resilience of the system. Adding to this the built-in signal analysis, authentication and monitoring algorithms further increases awareness of synchronisation status.
The development of technology in this area and its use in BITSTREAM solutions allows our PRTC solutions to be used in critical infrastructure applications.
Photo: Modular Managed Industrial Ethernet switch with PTPv2 time synchronisation server function and 4x 1/2.5/10Gbps Hyperion 500 interfaces.
Precision time monitoring and transport
The accuracy of precision time in power equipment will affect the ability to detect changes in phase, frequency, changes in indicated active and reactive power levels, harmonic signal levels and many other readings. Lack of synchronisation of time between devices or its high inaccuracy (difference in time relative to the atomic and between devices) will cause blockage of protections and erroneous triggering. It therefore becomes rational and necessary to constantly monitor the system for the quality and reliability of the time synchronisation of station and non-station devices dependent on it. Monitoring can be multifaceted and can be related to direct time comparison at different points in the system or indirect analysis of the signals generated. Such monitoring should be carried out continuously through dedicated solutions collecting historical data for later post-event analyses. For maintenance purposes, the system should enable direct alarming of exceeded thresholds and settings with interactive indication of the cause and location of the alarm. Such solutions have been implemented in QUAZAR-700 and the QuazarNeT software. The system allows direct monitoring and maintenance of the quality of precise time synchronisation in the station infrastructure as shown in Figure 2.
Figure 2: IEC 61850 station architecture for transmission and time synchronisation with monitoring based on BITSTREAM S.A. solutions.
BITSTREAM solutions in practice
BITSTREAM solutions offer multi-system and multi-frequency precision time clocks and switches with monitoring and support IEEE 1588 PTPv2 Power Profile and Utility Profile time synchronisation standards on Ethernet ports in Parallel Redundancy Protocol (PRP) and High Availability Seamless Redundancy Protocol (HSR) configurations. The devices offer switching matrix and port speeds of 10Gbit/s, which is important in the case of the large amount of broadcast traffic specified in IEC 61850 standards. Our devices support both Ethernet L2 layer and advanced L3 layer data transmission redundancy functions efficiently. PRP/HSR mechanisms offer lossless redundancy and ITU-T G.8032-compliant redundancy solutions guarantee switching times of less than 20 ms, minimising the risk of downtime in critical power systems. Built-in PoE++ IEEE802.3bt solutions enable power supply to peripheral devices such as cameras or sensors. Based on BITSTREAM solutions, technology network solutions such as the System of Technical Protection (SOT) can therefore be realised in a secure manner.
Photo: Managed network synchronisation quality monitoring probe with Quazar-700 time server function.
The future of time synchronisation in the energy industry
Precision time synchronisation technologies will play an increasingly important role in the development of the power industry. It is important to remember that the marking of samples with precision time stamps is a fundamental assumption of the most sophisticated IEC61850 solutions. Hence, due to the development of machine learning and artificial intelligence (AI) processes, data quality and parallel processing will be fundamental to automation processes in the power industry.
BITSTREAM, with its experience and advanced technologies, wants to support the changes in the modern energy industry by providing solutions that help build a more sustainable energy future. As a leading manufacturer in the field of time synchronisation and data transmission, our plan for the future is to continue developing innovative solutions for time-sensitive networks that meet the demands of the future.
Summary
GNSS precision time synchronisation technologies and BITSTREAM S.A. devices enable reliable and efficient operation of power grids. Nowadays, precise time synchronisation is becoming the foundation for innovative solutions in line with the requirements of the modern market, which contribute to a more sustainable and secure world. At BITSTREAM S.A., this is a priority for us, which is why our devices, designed for extreme conditions, are constantly being improved and are used in critical energy infrastructures around the world. With BITSTREAM S.A. solutions, the future of energy can become a reality today.
Magdalena Oleszko
Senior Marketing Specialist Bitstream
www.bitstream.pl
