COSTAM: COmparative performance assessment of STAtcom technologies based on Modular multilevel converters architectures



Project Start date: 1st October 2020

Duration: 28 months

Project coordinator: HEIG-VD/IESE

Projet Manager: M. Carpita Mauro,

Project partners 


Project funder


Project Context

Swiss energy strategy plans massive integration of Renewable Energy Sources (RES) (e.g., wind or solar power) into distribution power grids in the near future. This massive integration can be limited by issues like harmonics, voltage fluctuations and the increase of the faults risk. lndeed, the integration must address the national grid-codes. The use of power electronic technologies can help to address grid code compliance requirements (e.g. reactive power compensation, voltage control, fault ride through capabilities and so on) and secure the grid, protecting a renewable energy plant against network faults, voltage drops and other issues that often result in wind turbines or solar arrays tripping offline. Furthermore, they can contribute in provision of flexibilities (e.g., reactive power compensation) from distribution grids toward high voltage transmission grids.


Project main objectives

Many different power electronic technologies for reactive power compensation already exist. This project focuses on Static Synchronous Compensator (STATCOM) technologies benefits at the distribution network level. More precisely, the Modular Multilevel Converters STATCOM family is deeply investigated. This project goal is divided in 6 key objectives: 

1) Draw up a state of the art of the power electronic devices used as reactive power compensators. At the same time, validate why STATCOM topologies based on Modular Multilevel Converters architectures are the most promising STATCOM topologies to address the issues linked with massive integration of RES at distribution grid level and flexibility provision towards transmission grid level. A market technologies analysis is also realized to verify literature and present current STATCOM market trends.

2) Simulation modelling of the Medium Voltage (MV) distribution grid of SIL (Lausanne DSO, partner of the project) to deeply analyse STATCOM integration in a realistic situation.

3) Validation of the simulation modelling through reduced scale experimental tests at the 
ReIne distribution grid laboratory of HEIG-VD(flexible platform capable to emulate a wide number of real LV network topologies).

4) Analyse the benefits of STATCOM integration in the SIL grid model considering the RES hosting capacity increase and reactive power exchange between distribution and transmission grid. At the same time, STATCOM best location inside the MV grid, the control strategy, as well as the sizing of STATCOM reactive power is realised. This objective requires to set up a performance index to assess of the STATCOM effectiveness.

5) Thanks to the previous work, the best modular architectures will be selected and deeply investigated (control, simulations and tests from the power electronics point of view), based on the SIL MV grid case study. The aim is to validate the idea that these modular topologies are promising candidates in a real case study of a Swiss DSO.

6) Extend the study and tailor it to the needs of other Swiss DSOs. A suitable workshop will be organised with them to share the findings of this project and highlight other possible scenarios in which STATCOM can contribute to solve issues.

Expected main results

State of the art of STATCOM topologies
• STATCOM market technologies analysis
• SIL MV network case study simulation model definition
• Best size, location and high-level control of STATCOM to improve the MV network case study to face RES integration and flexibility provision toward the transmission network
• Low-level control definition (by simulations) for the most suitable STATCOM topologies in this case study. Particularly, unbalanced voltage conditions are investigated.
• Modification of existing modular converter prototypes (developed by IESE) to fit the case study most suitable STATCOM topologies. These prototypes operate in Low Voltage (LV).
• Test of these prototypes in the LV 
ReIne laboratory This lab will be configured to represent the SIL MV network case study in a reduced LV scale.

• Validation of the effectiveness of these modular STATCOM topologies in a real case application.
• Sharing of project findings with Swiss DSOs through a dedicated workshop. An extrapolation to other DSOs issues will be discussed. 


LV modular converters developed by IESE

LV modular converters developed by IESE


STATCOM converters literature summary diagram developed for best topologies selection in the COSTAM project case study.

Link to workshop presentation