Smart Transmission Grid Operation and Control

PROBLEM DESCRIPTION AND MAIN CHALLANGES

Ambitious targets have been set in Europe and elsewhere, including the Nordic countries, to meet societal goals for the transformation of energy systems to a more sustainable state. There are incentive mechanisms in place in many countries and regions that lead to large scale introduction of renewable and variable sources of electricity, typically wind and/or solar. At the same time, the European energy market is undergoing changes with the intent of creating a common internal market for electricity, similar to that of other goods and services. These two developments coupled with the increasing dependence of society on reliable supply of electricity for critical infrastructure poses a number of challenges for the uninterrupted operation and control of power transmission grids. As a result of these factors, power flows will be less predictable, and exhibit larger deviations with increasingly shorter time cycles, from predictable variations over the hours of a day, to large changes in power flow within minutes. At the same time, these changes must not impact the safe and reliable operation of the transmission grid. In addition, the continued increase of less predictable generation will put a burden of cross-border flows. To meet the future challenges the Nordic TSOs have made ambitious plans for transmission system investments in the next decade. Several new transmission lines are planned in the Nordic countries, in addition to HVDC connections within the Nordic grid and to the neighboring synchronous interconnections. As a result the future transmission networks will be more tightly interconnected, and potentially also more controllable as power electronic devices (such as VSC-HVDC and FACTS) continue to be deployed. As a result, more efficient and flexible ways of controlling and coordinating transmission system operation become necessary. In sum this leads to a requirement for better tools for planning and operation of interconnected power grids that work across traditional national boundaries. Such tools may become available through the development and application of phasor measurements for wide-area monitoring and control in the Nordic power grid.

This project deals with the development and implementation of GPS-synchronized phasor measurement (PMU) applications, and supporting information and communication technologies, for wide area monitoring and control in the Nordic power grid that will enable an orderly transition of the transmission system into a Smart Grid.

Motivation and main challenges:

1. The secure operation and control of power systems is faced with pressing challenges in the near future:

a: Integration of variable renewable generation in transmission (typically wind) and distribution (typically small hydro, bio, PV,) networks with uncertain behavior

b: Higher and more frequent variations in power exchange (Increased exchange capacity with new HVDC connections)

c: Provision of balancing services from Nordic hydropower become increasingly important

2. As a consequence, situational awareness becomes increasingly difficult:

a: Stronger and more rapid variations in power flows

b: The power system dynamic phenomena becomes increasingly

important as the system is being pushed to operate closer to its stability limits.

3. It is critical for the TSOs to have a wide-area observability of their transmission assets as well as their neighboring systems, and also to increase the granularity of their observability by monitoring important portions of sub-transmission and distribution networks

4. Automatic control systems are necessary to deal with fast changing dynamics of the power system and to address system-wide control challenges, particularly in view in the increased penetration of variable resources, and to prevent (or to reduce the consequences of) wide area blackouts.

5. From the above, the reliable operation and control of interconnected power systems requires the development of the appropriate information and communication technology (ICT) infrastructures that are scalable and secure. To guarantee scalability, reliability and high performance, these ICT systems need to consider quality of service (QoS) data delivery requirements imposed by different applications for both economical and efficient implementation.



METHOD AND WORK PLAN

The project will leverage the different competences in the Nordic countries to address the challenges in power system operation and control identified above; these challenges are key issues that respond to NER’s call for proposals by “creating more intelligent and improved grids”.

Interconnected power systems spread through large geographical areas, and their real-time control imposes stringent requirements on reliable synchronized measurement systems, information delivery and data stream management. Observe that due to the colossal size of transmission networks, there are many challenges to develop scalable and reliable information and control systems architectures that can provide the necessary performance for real-time control. Such architectures have not been previously employed in today’s power

networks.

The project is interdisciplinary because it involves not only competences related to power system analysis and control which will develop phasor data applications, but also expert proficiencies necessary to develop the supporting ICT systems enabling these applications.

Moreover, for the sustainable and reliable operation of the power systems of the future we have realized that not only technological advances are necessary, it is also important to increase the stream of trained professionals that can exploit these technological advances, a challenge that continues to be more apparent in the Nordic region.

Therefore, the proposed method comprises the development and exploitation of competences in three pillars, these pillars are the bastions for a “STRONgrid”: people, technology and applications.



-People:

This pillar is of much relevance due to the eminent aging of the power grid workforce in the Nordic Region. The project will provide PhD/PostDoc education, Nordic/international Workshops, and the establishment of the “Nordic SynchroPhasor Group (NSG)”, which will supply trained experts in Smart Transmission to the Nordic Region. With these elements we aim to establish leadership both in the Nordic region and Europe.

A Nordic Synchrophasor Group (NSG) will act as a meeting place for industry, academia, and others interested in the sustainable and continued development of technologies and applications of synchrophasors. We have already started this process by organizing a first meeting that gathered representatives from the different transmission system stakeholders. In this meeting the needs of the industry where clearly outlined to the academic partners, and this dialog served as our main driver for responding to this call for proposals from NER. A webpage containing the meeting’s presentations is available at:

http://nsg.ets.kth.se/



-Technology:

The project will establish a common Wide-area system development platform leveraging open source software solutions. The development platform consists of a software/hardware system allowing reception of PMU measurements, real-time processing of measurement data and power system data; and output of analysis, decisions and control actions as determined by PMU data applications.

In addition, this platform will be designed to deal with ICT infrastructurechallenges regarding scalability, data delivery considering quality of

service, and real-time performance. This platform will therefore provide a strong foundation for a new generation of wide-area monitoring and control systems.



-Applications:

The main objective of STRONgrid is the development of wide-area monitoring and control applications and their implementation in a common platform. These applications and their availability in a common Nordic platform will help to ensure the safe operation of the transmission as the applications and knowledge are phased into industry. This development will be pursued in close collaboration with TSOs, DSOs and manufacturers. The applications will include:

- Monitoring applications for improved situational awareness including novel state estimators paradigms and stability risk indicators (on-line power oscillation damping, voltage instability prediction, etc.), and appropriate visualization methods.

- Control applications (stabilizers, system protections, coordinated voltage controls)

- Data management for off-line analysis, and research on data compression and data mining applications.



-Deliverables:

1. Establishment of a common Nordic wide-area system development platform, PMU-data applications, and to address challenges in ICT regarding WAMS and WACS.

2. Training of PhD students and post-docs that can move directly into Nordic the power industry.

3. Bringing the latest technology developments into the industry through training programs, arranged during yearly workshops. The work plan therefore has been set up as follows:

1. Wide-area development platform (Main responsible partner: KTH):

Establishment and maintenance of a common, and open-source software Wide area system development platform comprised by PMUs, ICT infrastructure and application software leveraging open-source software solutions.

2. Wide are monitoring and control (Main responsible: Aalto):

Development and testing of applications in monitoring and control

3. Education and dissemination (Main responsible: DTU):

PhD and post-doc education. Dissemination through annual workshops. Mobility of personnel between industry and academia.

4. Project management and coordination (Main responsible: NTNU):

Management, coordination, and competence building for the Nordic Synchrophasor Group. Transition of the NSG into a permanent council gathering industry, developed human and technology competences after the project is finished.



PROJECT OBJECTIVE, EXPECTED PROJECT RESULTS

The GENERAL OBJECTIVE is to provide better tools for planning and operation of interconnected power grids that work across traditional national boundaries. These tools are becoming of critical need to meet societal goals for transformation of energy systems to a more sustainable state, and to enable large-scale introduction of renewable and variable sources of electricity. It is our vision that such tools can be developed by advancing phasor measurement technology and applications in wide area monitoring and control. Moreover, Nordic leadership in this area can be attained by establishing a common Nordic wide area system development platform. Working with the different stakeholders of the transmission system allows the STRONgrid participants to directly test

the developments with the primary users, and therefore allow for a straightforward adoption of the developed tools tools, thus “creating more intelligent and improved grids”. To reach this objective we will build three strong-pillars: people, technology, and applications; these are the bastions of the STRONgrid project.

More specifically, our common Nordic R&D platform will enable us to address the following SPECIFIC OBJECTIVES:

1. To innovate in power transmission monitoring and control through development of synchrophasor data applications and related technology

2. To addressing challenges and implement new approaches beyond the state of the art in ICT supporting infrastructure for data applications, such approaches will be based on QoS concepts which can guarantee scalability and performance of these systems

3. To provide Nordic added value by exploiting a common platform that fully utilizes the different competences in power engineering and ICT engineering, that address common operation and control challenges in power transmission.

4. To develop a strategic R&D potential by working closely with TSOs, DSOs and manufacturers to implement promising results from ICT and developed PMU-applications

5. To build competence through education and dissemination of results through Nordic and international workshops.






RESULTS and APPLICABILITY

The project results and applicability are directly related to the project deliverables. The expected results and related applicability of the results can be listed and explained as follows:

a. Establishment of a common Nordic wide-area system development platform.

a.1: At a first stage the platform will be comprised by a power system emulator currently being purchased by KTH, PMUs, phasor data concentrators, and specialized software. Within this platform applications can be developed and tested through reproducible experiments. To this end the emulator allows to reproduce scenarios for testing the performance and effectiveness of the developed applications.

a.2: At a second stage, when testing in the platform and emulator have been finalized, the applications will be tested with real measurement data from a university network of PMUs.

a.3: At a final stage the applications can be tested with TSOs involved in the STRONgrid project. Observe that these stages are not necessarily sequential, and can be carried out at different stages of the application development. This gives

direct applicability of the developed applications within the TSOs.

b. Development PMU-data applications for:

b.1: Monitoring: improved situational awareness through novel state estimators paradigms and stability risk indicators (on-line power oscillation damping, voltage instability prediction, etc.), and novel visualization methods.

b.2: Control: develop and apply techniques to exploit controllers such as stabilizers, VSC-HVDC, and FACTS; and to coordinate the control of these devices to enhance security.

b.3: Protection: wide-area protection schemes and special protection schemes exploiting synchrophasors

b.4: Off-line analysis: develop tools for disturbance analysis, and exploit techniques in data compression and mining which can provide metrics for risk indicators for use in on-line analysis. This has direct applicability and use within the TSOs involved with STRONgrid.

c. Defining and solving challenges in ICT for new generation WAMS and WACS.

c.1: Data delivery and architecture: due to the colossal size of transmission networks, there are many challenges to develop scalable and reliable information and control systems architectures that can provide the necessary performance for real-time control. QoS approaches will be used to develop the appropriate ICT infrastructure for real-time control.

The applicability of this is direct in the common platform architecture and the application development. Therefore it will also have application within the TSOs by providing technologies with scalable architectures that guarantee performance for real-time control.

d. Education and dissemination by annual workshops, training programs and PhD studies that provide direct applicability into the Nordic workforce of the future:

d.1: Training of PhD students and post-docs that can move directly into Nordic the power industry. This result will have applicability to the Nordic region by providing a stream of highly trained Smart Transmission experts and simultaneously ease the problematic of the aging Nordic workforce in power engineering.

d.2: Bringing the latest technology developments into the industry through training programs, arranged during yearly workshops. This result has direct applicability in updating current professionals with the advancements in the synchronized phasor measurements field and Smart Transmission Grids in general.