The main subject of Alberto Berizzi’s research are: • security issues of power systems. In particular, the security is taken into account during the analysis and control of electric power systems, their optimization, in particular with reference to voltage collapse, reactive power flow control and security of voltage control, also taking into account the Secondary Voltage Control typical of the Italian power system. Moreover, he worked on short-circuit current computations adopting IEC or ANSI Standards and on some mathematical issues linked to the study of large power systems, such as sparsity of matrices. • power system operation and planning and the electricity market operation. In particular, the following issues have been deeply investigated: zonal markets, determination of market zones, computation of Total Transfer Capacity, optimization using innovative – with respect to vertically integrated systems - objective functions, use of probabilistic concepts applied to the determination of TTC and finally to security. • large power system dynamic perturbations. This research activity has been started after the blackouts that stroke several European Countries in 2003, on impulse of the public investigation promoted (and carried out by the Politecnico di Milano) by the Italian regulator (AEEG). He also has been working on the dynamics and modelling of power systems, with the goal of developing tools to simulate large power systems taking into account non linearities and protections. • Finally, in the last years he has been leading some research projects dealing with the operation of Renewable in HV/MV/LV distribution systems, in both connected and islanded operation. In particular, congestion management, voltage control and islanding are the most important subject studied.