This paper presents an innovative active power filter design method to simultaneously compensate the current harmonics and reactive power of a nonlinear load. The power filter integrates a passive power filter which is a RL low-pass filter placed in series with the load, and an active power filter which comprises an RL in series with an IGBT based voltage source converter. The filter is assumed...

In this paper, an understanding of reactive power associated with power transmission networks is developed. To make transmission networks operate within desired voltage limits, methods of making up or taking away reactive power— hereafter called reactive-power control—are discussed. Before proceeding further, however, a thorough understanding of the reactive power in ac systems is necessary. Th...

The LVRT (Low Voltage Ride Through) is the main characteristic of every power system in faulty conditions. When fault occurs, it is essential for power system such as microgrid to control the voltage and frequency normally. Naturally in fault status, the unbalanced voltage and current are inevitable, but with the aid of LVRT technique, microgrid can keep stability in main system parameters such...

The important task for the operation of autonomous micro grids, is to share the load demand using multiple distributed generation units. In this paper to realize satisfied power sharing without the communication between DG units, the voltage droop control and its different variations have been proposed. Generally, in a lowvoltage micro grids, due to the effects of feeder impedance, the droop co...

In a deregulated electricity market, Ancillary Services are essential for the adequate operation of the bulk power system. In order to procure reactive power support, it is necessary to quantify the value of the VAr’s available sources within the system. This paper focuses on reactive power supply and voltage control on transmission networks. An optimization approach is proposed to determine th...

In this paper we propose a new configuration of the wind farm connecting with an electrical grid. The proposed Wind Energy Conversion System (WECS) is based on a two stages six-leg matrix converter using to drive a two Doubly Fed Induction Machines operating at different wind speeds. Each Doubly Fed Induction Generator (DFIG) is controlled through the rotor currents using the Finite Set Model P...

This paper provides a novel hierarchical control for VSI-based microgrids. The advantage of the provided control scheme is to maintain the frequency and voltage stability and load sharing against large-signal disturbances. A hierarchical control, consisting of three levels, is described. A new control loop based on PI controller, is presented. The new control loop has a great impact on increasi...

In order to detect grid harmonic and reactive current precisely and real time, this paper arrived at a method of harmonic and reactive current real-time detection applied to active power filter based on the three-phase circuit instantaneous reactive power theory. With Matlab simulation software, researches on simulation of harmonic detection means are carried out, and an analysis of the simulat...