• Interaction between microgrids and distribution system operators
  • Microgrid energy management and protection
  • Ancillary services and energy routers
  • Modelling and analysis of microgrids

2. Tertial 2018

Significant results (highlights and their innovation potential)

  • Blog post – A blog post written and published, describing the workshop on 2 May 2018
  • Memo completed: Microgrid protection – challenges and solutions
  • NTNU Opal-RT simulator was received, commissioned and tested

Meetings

  • Project meeting – WP4 workshop with the industry and research partners
  • There has been meeting with WP/task leaders of CINELDI
  • Start-up meetings with all the new MSc students (9 in total)

Deliverables

  • Workshop i CINELDI WP4: Mikronett i fremtidens distribusjonsnett
  • Conference publication: «Effect of Including Transient Virtual Impedance in Droop-Controlled Microgrids"
    • Fredrik T. Göthner/Raymundo E. Torres/Salvatore D'Arco/ Ole-Morten Midtgård, IEEE EEEIC (International Conference on Environment and Electrical Engineering), June 2018, Palermo

Milestones

  • Report on the literature review on microgrid protection is finalized

PhD Status

  • PhDs funded by CINELDI is now fully operative. Research plans are prepared and the first publications are appearing

Master theses

  • 9 projects/thesis works started this year covering all subtasks of the WP Microgrids

1. Tertiary 2018

Significant results (highlights and their innovation potential)

  • Publication: "Prony's method as a tool for power system identification in Smart Grids". The work of the MSc-students has importance in assessing dynamics in non-linear systems as microgrids with power electronic converters. PhD-students will continue the approach.

Deliverables

  • No specific deliverables scheduled within T1 but progress on deliverables of task:2 and task:3 on schedule
  • Restructuring of deliverables and Milestones in progress to avoid delays in reporting and to improve involvement of external partners.

Meetings

  • Internal workshops, kick-off and follow up of PhD-students
  • External networking meeting (on May 2, 2018)

PhD Status

  • Fredrik Göthner (T3) – preparing detailed plan, following courses, submitted conference publication
  • Kalpanie Mendis (T2) – (Jan 2018)- preparing detailed plan

Master thesis

  • Virtual impedance in ac microgrids (Anders Holvik- 2018)
  • Harmonic sharing in ac microgrids (Ruben Buchmann – 2018)
  • Signal analysis as a tool for power system identification and optimal control of power systems (Mads-Emil Kvammen og Sjur Føyen – 2018)

Results 2017

Microgrids (WP4)
The objective of WP4 is to develop concepts, technologies and models for microgrids and their interaction with the distribution system. The expected impact is a contribution to cost-efficient and robust integration of microgrids with the distribution grid, and a contribution to the integration of more distributed and renewable energy resources (DER) in the system.

The expected impact is a contribution to cost-efficient and robust integration of microgrids with the distribution grid, and a contribution to the integration of more distributed and renewable energy resources (DER) in the system.

Demonstrating simplified reference system for microgrids on the smart grid laboratory
A simplified reference system for studying isolated microgrids has been defined. The reference system has been used for developing and testing primary control strategies, a droop control that ensures cooperative power sharing and harmonic sharing. One of the challenges is deriving a droop controller that works when the line feeder impedances change dynamically and varies from largely resistive to more inductive characteristics, and still obtain proper sharing of power and current harmonics.

This research has been driven forward through collaboration between PhD candidate Fredrik Göthner and two master students. The simplified reference converter system and associated cascaded controllers have been successfully implemented in simulation environment, supporting master thesis and PhD thesis work. A related paper entitled Considerations of Virtual Impedance Implementation in the Synchronous Reference Frame was authored by Fredrik Göthner and Raymundo E. Torres-Olguin, and accepted for IEEE Environment and Electrical Engineering conference.

Two contributing master projects are Improved Power Sharing in AC Microgrids by Using Decentralised Virtual Impedance Control, and Advanced Harmonic Sharing Techniques for Microgrid Applications. The research is in collaboration and supervision by Professor Dr. Olimpo Anaya-Lara from University of Strathclyde. Extensive laboratory activities are planned starting March 2018, the previous simulation work and promising results are input for a hardware-in-the-loop implementation at the Norwegian Smart Grid Laboratory. The plan is to utilize and demonstrate the advanced facilities available at the laboratory, with the help from research partners at NTNU and SINTEF Energy Research.

State-of-the-art review of protection in microgrids
Through the work WP4 is creating high-level use cases identifying important challenges for relay protection custom to microgrids. One use case description has been proposed Adaptive microgrid protection, and a state-of-the-art review on protection in microgrids has been started, forming the basis for further research. The WP4 microgrid work package will partly run in cooperation with WP2 supporting research of a PhD candidate focusing on 5G for Low-Latency, Secure and Dependable Communication Services for Fault Handlings.

Opal-RT Simulator to be used in the planned PhD experiments  in the Norwegian Smart Grid Laboratory
Opal-RT Simulator to be used in the planned PhD experiments in the Norwegian Smart Grid Laboratory

Contact

Olav B. Fosso

Professor
995 89 248
Name
Olav B. Fosso
Title
Professor
Organization
Institutt for elkraftteknikk, Fakultet for informasjonsteknologi og elektroteknikk, NTNU