1. Department of Electrical EngineeringSchool of AutomationGuangdong University of TechnologyGuangzhou510006People's Republic of China
2. Brunel Institute of Power SystemsDepartment of Electronic and Computer EngineeringBrunel University LondonLondonUB8 3PHUK
3. Guangdong Provincial Key Lab of Computational Intelligence and Cyberspace InformationSchool of Computer Science and EngineeringSouth China University of TechnologyGuangzhou510630People's Republic of China