TT06 Grid forming converters connected to the transmission system – Influence of the type of grid forming control on the small signal stability (Part I)

Abstract

Today, a major share of the electronic converters is controlled under the presumption that they are connected to a strong AC voltage with a given magnitude and frequency in such a way that the converter can exchange an active and reactive power thanks to a current control. This control strategy of the converter is known as the grid-following control. The limitation of this solution has been well documented in the literature such as the challenge related to synchronization in weak grid. The grid forming control is proposing a new way to connect the power electronic converters which is supposed to solve these issues. The proposed tutorial is covering a wide overview about this type of control starting from the origin of the grid forming control in order to define a strong classification for the various types of control. A clear distinction will be made between grid forming control with or without current loop and the consequence in term of small signal stability will be addressed.

Course Outline (duration 8h)

First part : Theoretical presentation 4h

1 – Introduction (15 minutes)
2 – Description of the main types of control (30 minutes)
3 – Small signal stability analysis of different types of grid forming control (30 minutes)
4 – Current limitation in a converter driven by a grid-forming control – Transient stability (15 minutes)
5 – Implementation of the grid-forming converter on a VSC and an MMC (20 minutes)
6 – Different types of grid-forming application (20 minutes)
7 – Testing grid forming capability, pilot projects and barriers for an industrial deployment (30 minutes)
8 – The integration of grid forming capabilities into connection network codes (40 minutes)
9 – Conclusion and perspectives (10 minutes)

Second part : Practical exercises 4h

Practical exercise 1: Study of the inertial effect brought by a grid forming converter (45 minutes)

Practical exercise 2: Study of an HVDC link (45 minutes)

Practical exercise 3 : Small signal stability analysis (1h30)

Instructors

Xavier Guillaud
Centrale Lille, France
xavier.guillaud@centralelille.fr

Frederic Colas
ENSAM- Lille, France
frederic.colas@ensam.eu

Carmen Cardozo
RTE, France
carmen.cardozo@rte-france.com