This paper presents voltage control scheme by using directly voltage-controlled distributedenergy resource units (VC-DERs) of an islanded microgrid to provide overcurrent,voltage sag and harmonics protection. The overcurrent protection scheme detects the fault, limits the output current magnitude of the DER unit, and restores the microgrid to its normal operatingconditions subsequent to fault c...

This paper deals with conceptual study of unified power quality conditioner (UPQC) during voltage sag and swell on the power distribution network and researches profoundly on the coordinated control of UPQC (Unified Power Quality Conditioner). By analyzing the radical reasons of coupling effect between UPQC series unit and shunt unit, a simple and practical coordinated control strategy for UPQC...

The dynamic voltage restorer (DVR) provides a technically advanced and economical solution to voltage-sag problem. As the voltage-restoration process involves real-power injection into the distribution system, the capability of a particular DVR topology, especially for compensating long-duration voltage sags, depends on the energy storage capacity of the DVR. The interline DVR (IDVR) proposed i...

⎯This paper proposes fractal patterns for power quality (PQ) detection using color relational analysis (CRA) based classifier. Iterated function system (IFS) uses the non-linear interpolation in the map and uses similarity maps to construct various fractal patterns of power quality disturbances, including harmonics, voltage sag, voltage swell, voltage sag involving harmonics, voltage swell invo...

This paper presents a method for determining the network lines and buses where the occurrence of faults will lead to voltage sags causing severe financial losses in the power system. The proposed method is based on a typical stochastic assessment of voltage sags. The network regions where fault occurrences will simultaneously lead to voltage sags at different sensitive load points can be determ...

Dynamic Voltage Restorer (DVR) is used in power distribution system to protect sensitive loads in voltage disturbances. The performance of DVR is related to the adopted configuration and control strategy used for inverters. In this paper, an asymmetrical voltage-source inverter controlled with fuzzy logic method based on hysteresis controller, is used to improve operation of DVR to compensate v...

Nowadays power quality is term widely used in power systems wherein the voltage, current, and phase angle are widely discussed and used. The Time Frequency Representation (TFR) provides a powerful method for identification of the non-stationary of the signals. This paper proposes a Discrete Orthogonal S-Transform (DOST) for analysis and visualization of voltage distortions with timevarying ampl...

This work deals with modeling and simulation of multi bus system using D-STATCOM. Voltage sag is increased by connecting a heavy load. The sag is mitigated using D-STATCOM. The circuit models and simulation results are presented. The Simulation results are compared with the analytical results. KeywordsDistribution Static Synchronous Compensator (D-STATCOM)