Power quality is one of major concerns in the present. It has become important, especially with the introduction of sophisticated devices, whose performance is very sensitive to the quality of power supply. The dynamic voltage restorer (DVR) is one of the modern devices used in distribution systems to improve the power quality. In this paper, emergency control in distribution systems is discuss...

This paper presents an algorithm to detect and classify voltage sag causes based on Wavelet Transform (WT) and Probabilistic Neural Network (PNN). A technique is required which is capable of extracting both time-frequency information to identify the causes which contribute to power quality disturbances. Wavelet transform based on multiresolution analysis is used to extract the features from the...

Voltage sags/swells and harmonics are recurring problems in electric energy distribution systems. In order to solve these issues, several dynamic voltage restorer (DVR) topologies, such as the conventional three-wire DVR, have been proposed literature. Despite its capability of mitigating disturbances, many researchers established that DVR cannot compensate for zero sequence disturbances. this ...

According to the coordination control of a dynamic voltage restorer (DVR) and an inductive fault current limiter (FCL), this paper proposes efficient low-voltage ride-through (LVRT) scheme for doubly fed induction generator (DFIG) based wind turbine. The DVR is located DFIG’s stator circuit stabilizing terminal decreasing current. FCL connected rotor suppressing overcurrent protecting converter...

Total complaints related to voltage sags are about 80 % of all the complaints due to power quality transients. AC Contactors are designed to disconnect the load or circuit they control when the main power supply is intentionally interrupted. The sensitivity of AC coil contactors to the applied voltage is thus a potentially weak link in industrial processes. This paper shows the test results obt...

Voltage sag is a serious power quality problem affecting domestic, industrial and commercial customers. Voltage sags may either decrease or increase in the magnitude of system voltage due to faults or change in loads. In this paper a switch mode AC BuckBoost regulator is proposed to maintain voltage across a medium size domestic appliance constant during long period of voltage deviation from th...

The Electrical power system contains a wide range of electrical and power electronics components in industrial and commercial applications. The power quality will be affected by various factors like ripples contamination, voltage sag and voltage swells due to the increase in loads of non-linear type like large power electronics converters such as IGBT and GTO, rectifiers, voltage and current gl...

For grid-connected DFIG-based wind turbine, Fault Ride Through (FRT) or Low Voltage (LVRT) capability is vital problem that need to be improved. This paper proposes an Active Disturbance Rejection Control (ADRC) strategy applied Doubly Fed Induction Generator (DFIG) based Wind turbine (WT), which integrates a Dynamic Restorer (DVR). The DVR connect in series the DFIG output terminal and utility...

Voltage sags originating in ac supply systems can cause nuisance tripping of variable speed drives (VSDs) resulting in production loss and restarting delays. In ac VSDs having an uncontrolled rectifier front-end, the effects of voltage sags on the dc link causing dc under-voltage or ac overcurrent faults initiate the tripping. This paper suggests modifications in the control algorithm in order ...

Dynamic Voltage Compensator (DVR) is able to handle the dynamic power quality problems in distribution network, such as voltage sags and voltage unbalance, and the parameters of the output filter will have important affect on the compensation results. In this paper, the parameter design method of the output filter of a cascaded H-bridge based DVR applied in medium-voltage distribution grid is s...