Classical controller based AGC of a hybrid multisource power system incorporating distributed generation

The article exhibits automatic generation control of an interconnected realistic multi-source two area system. The system comprises of two thermal units in Area 1 and one hydro and one thermal unit in Area 2 and, incorporating distributed energy generation (DG) in Area 1. Non-linearity's such as appropriate generation rate constraint of 3%/min for thermal units, 270%/min for rising and 360%/min for lowering action of hydro units are incorporated along with governor dead band of 0.036 Hz for both thermal and hydro unit. Classical controllers are employed as secondary controller to reduce the area control error due to the intermittent non-conventional sources in distributed generation and thereby reducing the frequency and tie-power deviations. Stochastic fractal search (SFS) algorithm is utilized to tune the classical controller gains and other parameters simultaneously. Performance comparison of classical controllers such as proportional-integral-derivative (PID) and proportional-integral-derivative with first order filter effect (PIDN) in absence of DG unit establishes the superiority of PIDN controller over PID. Simulations are carried out in presence of DG unit in Area 1 by incorporating wind turbine generator system (WTS) and dish sterling solar thermal (DSTS) plant that are tested with step input as well as random input. The solutions obtained from the robust SFS based PIDN controller ensures that the frequency and tie-power deviations are within safe limits when random pattern of WTS and DSTS plant are applied in the DG unit. Also, a part of the total generation shared by the DG unit helps in balancing the real power output and hence the decrease in deviations occurs.