1. Department of Electric Power EngineeringNorwegian University of Science and TechnologyTrondheim7495Norway
2. SINTEF Energy ResearchTrondheim7465Norway
3. Abengoa ResearchSevilla41014Spain
4. Department of Electrical EngineeringTechnical University of CataloniaTerrassa08222Spain
5. Department of Engineering CyberneticsNorwegian University of Science and TechnologyTrondheim7495Norway