The main research areas of the group of transmission systems are power system security and power system damping.
Usually (n-1) criterion is used for grid planning and operation. This means that the power system can withstand a single fault followed by a trip of the faulted component. This criterion does not lead to constant security, since frequency of critical faults and power flows of the grid vary. The aim of the research project of power system security is to find a more analytical way to estimate the security and possibly to an additional grid operation principle to be used with the traditional (n-1) criterion.
The other research project deals with damping of electromechanical oscillations in a power system. Damping of electromechanical oscillation sets the limits for transmission capacity in some power flow situations. At the moment the transmission capacity is calculated by off-line simulations. This leads to conservative limits, where all the possible capacity of the transmission grid can not be utilized. Real-time monitoring of power oscillation damping could help to better utilize the full capacity of the power system without decreasing the security. The goal of the study is to find out basic conditions of the damping estimation, factors affecting the damping and possibly to develop damping estimation algorithms. Head of the research group is Professor Liisa Haarla and the researcher is M.Sc. (eng.) Jukka Turunen.
There also is research that deals with impacts of large scale wind power on the transmission grid.
The group is led by Professor Liisa Haarla.