Thyristor rectifiers are widely used in electric railways in order to control the speed. As a consequence of their usage in addition to substantial input lead current, an enormous amount of harmonics is injected into the grid. To avoid such harmonics as well as reactive power compensation, reactive power hybrid filters consisting of active and passive filters are utilized. Regarding different p...

This paper proposes an MPC - based (model predictive control) scheme to control active and reactive powers of DERs (distributed energy resources) in a grid - connected mode (either through a bus with its associated loads as a PCC (point of common coupling) or an MG (micro - grid)). DER may be a DG (distributed generation) or an ESS (energy storage system). In the proposed scheme, the set - poin...

Usage of flywheel energy storage system (FESS) is a common method for frequency regulation due to its high power injection capacity and long life time. FESS is equipped by two back-to-back inverters including grid-side inverter and machine-side inverter. In conventional method, the machine-side inverter sets the active power and machine flux while grid-side inverter sets the reactive power and ...

This paper presents a robust control scheme for distributed generations (DGs) in islanded mode operation of a microgrid (MG). In this strategy, assuming a dynamic slack bus with constant voltage magnitude and phase angle, nonlinear equations of the MG are solved in the slack-voltage-oriented synchronous reference frame, and the instantaneous active and reactive power reference for the slack bus...

In this paper, a new sensorless model reference adaptive method is used for direct control of active and reactive power of the doubly fed induction generator (DFIG). In order to estimate the rotor speed, a high frequency signal injection scheme is implemented. In this study, to improve the accuracy of speed estimation, two methods are suggested. First, the coefficients of proportional-integral ...