In recent years, power electronics devices have evolved, and used for varies applications. Also, this device caused the problem of power quality in electrical system. In the utility side arc furnaces, variable frequency drives (VFD), personal computer, fluorescent lamp such non-linear load produces current harmonics. For consumer and distributed side the power quality is an important issue. The active power filter which is capable for improving the power quality and reactive power compensation. In this paper the harmonics problem which is created by non-linear load is discussed. Shunt active filter is used for eliminating the harmonics from non-linear load and in the retrieval technique for controlling the current hysteresis current controller is used. In this paper for producing the reference current instantaneous reactive power (PQ) theory is used. The simulation result of shunt active filter using PQ theory is carried out using Matlab-Simulink toolbox.

Currently, Light Emitting Diode (LED) lamps are used mostly in street lights. As these street lights are illuminated at full capacity throughout its duration, this results in a huge power loss. This paper discusses a intensity controller system, which solves the problem of power loss. The main aim of this paper is to run the street lights on low intensity when there is no one in the vicinity and turn on to full intensity when there is presence of individuals in the surrounding of the street light. The process of dimming the light according to the requirement of the public will result in saving of energy. The analysis of energy consumption with and without intensity controller is discussed. Also the proposed system is tested on a comparison basis with other proposed and existing system in order to conclude the better results among them.

For study of filter of shunt active (SAPF) with SMC controller is attached to PI controller in two different configuration and to find better result such as lowest THD and improved power factor. The proposed system consist of three phase three winding transformer with star connected secondary winding which is tapped to shunt connected active power filter. This types of transformer arrangement rundowns the filter side voltage, avoiding the demand of high bandwidth step-down transformer. That type of arrangement reduces voltage rating of APF switches and also increasing frequency of switching limit. With the help of active filter which is connected on shunt they are compensated reactive power to the system. This article proposes the PI with SMC controller for improvement of power quality by shunt active power filter (SAPF). Here the SIMULINK model of SAPF and control technique by PI with SMC controller has been carried out in MATLAB SIMULINK.

Automation is a need of today's world. By introducing automation in traditional systems, one can achieve greater accuracy and flawless performance of the system. Toll monitoring system is taken as an object and automation is implied using proximity sensors and PLC- SCADA programming. The resultant system becomes fully automatic. The key point of the system is the PLC program itself drives the boom-barrier as well as street lights for conservation of energy. The prototype of toll monitoring system is designed using sensors and relays and Relay Ladder Logic (RLL) is embedded in PLC using SCADA.