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Improvements in planning, maintenance and control of power systems can be achieved through data analysis. Decentralized monitoring systems have numerous drawbacks because of limits imposed by manufacturers of different equipment, lack of interconnectivity and limited specialized staff who maintain such systems. Since equipment of different manufacturers is often installed, numerous inconsistencies arise and interoperability is almost impossible to achieve. These disadvantages fostered the development of an all-in-one process system to allow collecting and archiving data, data exchange between subsystems and the development of applications and tools based on database technology, to improve processes in power systems. This paper presents a centralized analytical system which centrally collects data from devices, independent of manufacturers, types of communication protocols they use or the technological generation of the installed equipment.

Automation systems in modern power facilities can justifiably be viewed as computer systems (IT systems) mainly due to the way information is exchanged through the communication network. In general, all equipment installed in such systems today has several communication interfaces, which allows it to communicate independently to multiple systems and / or to be applied in multiple services. Additionally, vertical communication is increasingly present in modern automation systems, which means direct access to information and devices from the highest level to the lowest level, whereby the exchange of data takes place throughout the entire communication system. Due to all of the above stated, automation systems in power facilities have become increasingly vulnerable in terms of cyber security, and therefore it has become necessary to apply protection mechanisms to ensure security of communication and data, but also the functionality of the power system itself. The key techniques or measures that must be applied in the digital substation PAC system related to cyber security requirements will be presented in the paper.

The loss of synchronism within the power system or between mutually connected systems can occur in certain operating situations like important power line outages or short circuits. If such a loss of synchronism is manifested, the asynchronous areas have to be isolated before the generator is damaged and other outages start occurring throughout the system. A new model for hydro generator loss of synchronism protection based on the direct load angle measurement is proposed in the paper. The real time load angle measurement has been implemented in the proposed loss of synchronism detection model. The functional testing of load angle measurement algorithm was conducted in the real environment on a hydro generator while the testing of the proposed loss of synchronism detection model has been performed in a laboratory testing environment.

The systematization of process information in secondary systems includes the standardization of process information flowing from the substation to the power systems’ control center. Process information includes all signalization, measurements, commands and other types of information used in power system facilities. The purpose of the systematization of process information is to create a process information catalogue, listing all process information used in the secondary system and thus further enabling the digitalization of the engineering process. This paper describes the issues behind the systematization of process information in SPAC systems of power system facilities in TSO and DSO. Additionally, the paper lays out the program solution or application for setting up the process information catalogue with the main goal of simplifying and speeding up certain phases of the engineering process.

The development of automation technologies in power systems, especially in substations, during the last decade significantly changed the concept of secondary systems. These changes have been one of the main impulses for the implementation of the IEC 61850 standard and the fully digital substation concept. In the digital substations all measures are sampled and all signals and controls are digitalized close to the source, and then transmitted over the Ethernet network to the IEDs which collect and process data and control the system. In the digital substation the source of digital measured values is the merging unit that publishes sampled values on the process bus according to the IEC 61869-9 standard. Along with the sampled values, phasor measurements are increasingly used in power systems. This paper gives a description of the developed smart measuring unit which encompasses the stand-alone merging unit and phasor measurement unit functionalities as well as the results of the functional tests.

The article presents remote service access to substation control system equipment implemented in Transmission Area Rijeka, as well as different monitoring and maintenance management approaches that were implemented and evaluated.

Continuous development of IEC61850 standard introduces need for new approaches in design, erection, testing and maintenance of substations. With process bus development and deployment we are moving towards the digital substation, the IEC 61850-based substation using Stand Alone Merging Units, Switch Control Units and / or Non-Conventional Instrument Transformers and featuring both station bus (IEC 61850-8-1) and process bus (IEC 61850-9- 2). The use of digital buses for the transmission of Sampled Values and Signals opens space for implementation of distributed applications which create new test cases in substation protection, automation and control system (SPACS) testing. The fact is that the testing processes should be reviewed taking into consideration that every function which is implemented in the SPACS has to be testable and there should be a method for testing it. There are number of use cases that should be covered like testing of logical node, functional chain testing, integration tests, factory acceptance tests, site acceptance tests and maintenance. The functionality provided by IEC61850 standard should be used to monitor this system in order to minimize the testing.

The recent developments in the technology make acquisition, sampling and transmission of measured values possible with such precision as to fulfill the power system control and protection requirements. Nonconventional instrument transformers implementation and measured values transmitting over a IEC61850 process bus introduce new qualities into the system but also require that system is adapted to them. Since the protection and control systems with process bus are at the beginning of their implementation it is clear that there are lot of questions regarding the behaviour and characteristics of such a system. Process bus will bring the benefits in the protection and control system design and engineering but before this it must be proved that the technical characteristics of the conventional system will not be degraded.

The concept of the Smart Grid originated from the desire to make the grid smarter, safer, and more reliable using advanced sensors, communication technologies and distributed computing. A smart grid will allow integration of new sustainable energy sources, such as wind, solar, off-shore electricity, etc. There are four attributes of the Smart Grid that need to work interactively for this concept to be a reality. These are: Technology, Standards, Public Awareness and a Policy of Incentives. At present there are efforts from vendors to develop technologies which will become building blocks of this grid. At the same time standards are being developed which will make technologies from different vendors interoperable so that many players will be able to participate giving customers a broad choice. But all of these will depend on whether the public will find value in participating in this opportunity. And this will depend on two things – awareness and incentives – which are interrelated. The public must be made aware of the benefits of participating, and at the same time there must be incentives for them. There must be policies and regulations in place that will encourage participation by creating a differential pricing structure for the electricity consumed. At the end smart grid development in Croatia will be presented.

Numerical relays joined with IEC61850 standard opened a great possibility to migrate interlocking logic in substations from hardwired to logic executed by numerical control relays. This introduced a big savings in time and materials required for hardwire solutions but it also created a need to develop new testing procedures and tools that will allow testing it and fully exploiting its advantages. Further more such a products are needed for all other functionalities which are migrated from wiring to IEC61850 communication based solutions. The study case for this article is refurbishment of the 400/220/110kV Mintia substation. A rather big SS of roughly forty bays needs to be refurbished bay per bay, while rest of it is in operation. With such a setting it was a challenge to prove functionality of interlocking system with only typical bays prepared for factory acceptance test. It was decided to use IEC61850 protocol simulator in order to make interlocking functional and available for testing and presenting to customer. As the configuration of substation is rather complicated, including transfer busbar and more sections on regular busbars, required logic was complicated. In order to test complete logic or interlocking schema it was necessary to simulate change of state for large number of elements.