Abstract:The non-renewable energy resources are limited and depleting gradually. As such, energy security has attained the greatest amount of attention globally than ever before. In the meantime, energy crises are already affecting the developing countries such as Pakistan, even though one-third of the population of the country is not even not connected to the national electricity grid. The population with access to on-grid electricity is enduring load shedding of more than 12 h a day. This situation is alarming and require immediate attention is required so as to add alternative energy resources to the country, which has long been relying on imported fuels. It is, therefore, high time that the abundant potential in the renewable energy resources of Pakistan such as solar, wind, and biomass are harnessed. These renewable energy resources are economical and environmentally friendly, and thus considered as sustainable, and the utilization of these in meeting energy demands can help to conserve conventional resources early diminishing. This paper provides a detailed description of the energy consumption and load-shedding scenario in Pakistan thereby focusing specifically Sindh and Baluchistan provinces. Since, wind energy is considered one of the cost-effective renewable resources, six potential sites in these two provinces are considered in this study. These sites lie within 250 km of the southeastern and 800 km of the southwestern regions of Pakistan. One-year wind speed data have been reported for variable heights of these proposed sites which represent to have an annual average wind speed of 6.63 m/s and 5.33 m/s respectively. The power generation data for these location of two provinces is 7.653 GWh, and 5.456 GWh per annum respectively. This study also elaborates on the advantages and disadvantages of harvesting and installing the wind energy and provides a technical proposal for the generation of electricity from the wind in the selected remote zones which are off the national grid. The findings of this paper will help concerned government departments to devise appropriate policies and attract investment in the wind energy sector to eradicate the on-going electricity crisis.

UPS Uninterruptible power supply) is used as backup when the input source, usually the national grid, fails to give power to a load. In addition to the growing use of electronic power devices in industrial and residential systems, such as UPS, controlled rectifiers, SMPS (Switch Mode Power Supplies), and DC Converters, there is a serious problem caused by harmonics in AC mains, which lowers the power quality. Harmonics can cause a variety of problems, including sensitive equipment failure, resonance issues, heated wires, power loss, and inefficient distribution systems. A passive or active power filter could be used to reduce harmonics. However, passive filters are more difficult to design and are bulkier. With the advancement of power electronics, active power filters were developed, and the best combination of both was supplied in the form of hybrid active power filters (HAPF). This study shows an approach to minimizing the harmonics contained in the output of a UPS connected to a nonlinear load. Experiments with several UPS types have been conducted under various nonlinear loads, as well as charging and discharging of batteries, and the proposed technique significantly reduces harmonics in a system with a HAPFs (hybrid active power filter) based on a unique FLCC (fuzzy logic current controller). In this paper, we use a fuzzy logic controller to generate pulse width modulation (PWM) switching signals in a single-phase half-bridge HAPF. The operation of the proposed PWM-FLCC will be studied in a steady and transient state. Based on a connection between the uninterrupted power supply (UPS) supplying a single-phase power to a nonlinear load, different power filter topologies and a brief review of reference current extraction (RCE) methods used in this study were also included and the most common configurations have been compared with their advantages and disadvantages to ensure the right selection of the power filter for UPS connected with the nonlinear load. The results of the investigation demonstrate that the HAPF with the fuzzy logic current controller has reasonable performance, with a significant reduction in current THD down to 1.09%, as per IEEE-519 standard.

This paper discusses a novel analysis scheme based on the hybrid interface of Optical USB and Power Quality Meter for measuring Total Harmonic Distortion (THD) that exists in the Uninterruptable Power Supply (UPS) system and connected load. The designed hybrid interface experimentally analyzes the power quality and harmonics of the Uninterrupted Power Supply (UPS) system, and mitigation is proposed with the proposed Single-Phase Hybrid Active Power Filter (HAPF) based on instantaneous Power Theory (PQ) with hysteresis control technique and synchronous frame reference (DQ) with hysteresis control techniques at nonlinear load. This study authenticates and gives appropriate measurements in analyzing the harmonics and voltage distortion during conversion of power. The designed work offers the compensation and elimination of harmonic currents using PQ and DQ theory at different nonlinear loads. The proposed HAPF for the UPS system has demonstrated the significant reduction in THD using proposed Power Theory (PQ) with hysteresis control technique from 46.58% to 1.51% and by using DQ theory with hysteresis control technique has reduced THD from 46.58% to 1.38%. Finally, the results are compared between PQ and DQ. It is validated via results that DQ theory eliminated harmonics and also having less THD as compared to PQ-theory. Furthermore, one of the key aspects of the work is the analysis of power quality using Optical USB Interface (OC4USB) and FLUKE series power quality analyzer.

This article describes how a drastic failure of a machine is caused by insulation collapse which results heavy interruption as well as losses. The stable operation of a generator mainly depends upon the stator winding insulation. In past, various testing and repairing techniques have been applied in order to analyze the insulation life. However, in this context, a complete stator windings insulation analysis have been carried out by testing and monitoring techniques such as insulation resistance, di-electric absorption ratio, polarization index before repair and after rehabilitation work, ac & dc high voltage, dc resistance test of winding coils, as well as surface potential test, no-load test and short circuit test. It basically reflected the insulation life of stator winding and helped to take remedial measures. This research techniques will pave the way to overcome such failure in machine and recommended the interval based tests for safety purpose.

Nowadays every sector from industries, commercial to residential uses the Uninterruptable Power Supplies (UPS) System and power electronics devices due to their essential need of power and application however these are beneficial and vital for each sector but they produce harmonics in the power system. These harmonics generate electrical disturbance and distort waveforms which results in power loss due to poor power quality. That is why to enhance the standard of power provision this harmonic disturbance should be lowered with implementation of Passive, EMI and other Active Power Filters (APF) [1]. Energy security and reliability are present-day problems and unnecessary load shedding is a great issue in Pakistan as well as in other backward countries due to rising energy consumption demand and reduced provision. Reserve supply through UPS is a temporary remedy for customers in such circumstances. When national grid power is not available and primary source fails to recharge the batteries, UPS will supply power automatically and maintains a continuous Power without delay or transients [2]. During the power conversion in rectifier and inverters (AC-DC-AC Converters) harmonics currents and voltage distortion caused in Uninterrupted Power Supply UPS requires up to date and rapid filtering method to remove and mitigate harmonics in order to have desired power transfer, raise overall efficiency, reduce losses, enhance accuracy and lifecycle of apparatus. UPS offers instant protection which also makes power losses significantly due to harmonic current [3-6]. It is the need of the time Abstract: Hybrid Active Power Filter (HAPF) is designed and applied for Uninterrupted Power Supply (UPS) System to mitigate harmonic currents in UPS during the power conversion from rectifiers to inverters (AC-DC-AC Converters). Various UPS types and topologies are used for continuous power supply without delay and protection to connected loads. In spite of the fact that UPS is one of the power quality apparatus but it has also drawback of disturbing the power system quality of system by current harmonics and voltage distortion during conversion of power. Passive and EMI Filters could not eliminate harmonics effectively from UPS system therefore it requires modern, rapid filtering method as well combination of Active and Passive Filters. Proposed model of HAPF for UPS System could mitigate current harmonics for optimal power transfer and minimize losses, increase overall efficiency, reliability and life span of equipment. Higher harmonic current and higher voltage distortion leads to greater power loss. In this paper the (d-q) theorem is applied for the identification of harmonic currents. The d-q theorem and calculation creates the signal of reference compensation current and this produced signal of current is tracked by the yield current of the voltage source converter.. Hysteresis based controller for HAPF is applied to create the switching signals to regulate and maintain the voltage source converter output currents. Harmonics and effi...