Search

Cascade controllers improve the frequency profiles of the microgrids during power fluctuations. In this paper, a proportional–integral-proportional-derivative (PI-PD) cascade controller is applied to minimize the frequency disturbances of a fully renewable microgrid with electric vehicles. The superiorities of the PI-PD controller are tested at different operating conditions of generation, demand, and comparisons are made with a classical controller. The test system is completely incorporated with biodiesel, biogas, and solar renewable units. In such a completely renewable environment, power balancing is a difficult task. Therefore, the effect of storage units and electric vehicles is also investigated to mitigate active power imbalances. Furthermore, the optimal power generation concept is incorporated with variable participation factors of biodiesel and biogas plants which improves the load frequency control objectives of the isolated microgrid. For all the simulation case studies, the controller's gains are identified by using a magnetotactic bacteria optimizer using the MATLAB-SIMULINK platform. [ABSTRACT FROM AUTHOR]

Intelligent threshold value improves the speed and accuracy of any fault detector unit. But in the literature, any such traditional threshold selection mechanism is not available to implant in the fault detector unit of protective relay. This paper introduces a swarm intelligence-based threshold setting mechanism for fault detector. In this context, the Euclidean distance approach (EDA) with a single detection index is used for transmission network protection. The detection index function is formulated with fault parameters on a priority base. Further, the modified particle swarm optimization technique with adaptive inertia strategy is used to identify the optimal threshold value of detection index function. With swarm intelligence based optimal threshold, numerous cases are investigated on a test power system and obtained results show the efficacy of the method. [ABSTRACT FROM AUTHOR]

Summary: Series compensation improves the power transfer capability and the stability of a transmission system. Inclusion of series compensating devices along with their protecting equipment introduces the problems to conventional protective relaying during power system faults. In this paper, a new protection strategy is proposed based on the instantaneous active and reactive power variations. The applicability of the proposed method to a series compensated transmission system is studied with numerous fault cases. Instantaneous power quantities are measured, and respective active and reactive power quantities are reproduced onto a two‐dimensional coordinated system with reactive power as ordinate and active power as abscissa. The locus of ordered pair of instantaneous power quantities (p(t), q(t)) forms a P‐Q trajectory. The quadrant in which the starting point of P‐Q trajectory (p0(t), q0(t)) lies is computed and taken as reference. This P‐Q portrait is analyzed to detect the fault depending on the condition that the operating point shifts its quadrant under fault condition. Fault will be classified based on the polarities of extracted powers. Classification tree is formed by a set of yes/no consequences to classify the fault. The proposed method is tested for different types of faults, at distinct locations and fault inceptions on 500‐kV, 50‐Hz test system. Results thus obtained show the potentiality of proposed strategy for the protection of series compensated transmission system concerning the speed, computational burden, and mathematical complexity. [ABSTRACT FROM AUTHOR]