Power optimization and static performance investigation of an island-mode doubly-fed induction generator (DFIG)
This paper presents a performance investigation of power optimization by using a Proportional-Integral (PI) controller in a doubly-fed induction generator (DFIG). A detailed, dynamic model of a DFIG based on variable speed systems is presented in the dq-synchronous reference frame. Along with different controller types, a PI controller is chosen. Moreover, besides active and reactive power control, constraints and power optimization are discussed. Matlab software was used for simulation.
Microgrid control principles in island mode operation
Microgrids are small power systems capable of island and grid modes of operation. They are based on multiple renewable energy sources that produce electricity. Managing their power balance and stability is a challenging task since they depend on quite a number of variables. This paper reviews microgrid control principles according to the IEC/ISO 62264 standard along with an example system where electricity is supplied by two renewable energy devices including a PV panel, a Doubly-Fed Induction Generator (DFIG) wind turbine and battery storage. The storage system provides the integral system backup and the storage of surplus energy from renewable sources. System simulation is made with PSCAD/EMTDC software.
Suppressed Light Emission of the Reaction Zone in Detonation
THE detonation of high explosives in water can be photographed with an open camera and a flash light as the explosive gases do not emit light. The method has been used1 to investigate the spread of shock waves and explosive gases, and to investigate the initiation by shock waves2. We have found that it can be used also in certain gases such as butane and propane. The method is not suitable, on the other hand, for explosives with two levels of detonation velocity in the case of low velocity. A great part of the reaction then occurs after the reaction zone has passed and the expanding explosive gases are very luminous even in water.