Power Quality Research Paper

3.1 INTRODUCTION

Power quality is “the concept of powering and grounding sensitive electronic equipment in a manner that is suitable to the operation of that equipment.” (As per IEEE standard 1100).

From the time when the electricity was discovered, the generation, distribution and use of electricity have evolved gradually. New and innovative resources to generate and use electricity added spark to the industrial revolution and from that time the scientists and engineers have contributed to its continuing development. Initially, electrical machines and devices consumed large amounts of electricity and yet performed well. The machines were designed which had their performance as the primary concern and cost as the secondary concern. But as

The major issue for the consumer is the reliability and quality of power supplied at the load centers as hundreds of generating stations and load centers are interconnected with each other. Generation of power in most of the developed countries is reliable but the power quality of supply side is not. A customer requires a continuous and un interrupted supply of energy in order to maintain the life and the quality of their equipments.

A power quality problem is any problem that is manifested in voltage or current leading to frequency deviations which results in the failure or disoperation of customer equipment. Power quality has serious implications on the consumer side equipments. Power system, especially the distribution system, has number of non-linear loads which drastically affect the quality of power supply. These loads may deform the supply waveform. Some system events also contribute power quality problems like capacitor switching, starting of motors and faults. The after effects of such quality problems results into large economic

• Transient voltages and currents.

• Harmonic content in the waveform for ac power.

• Continuity of service.

The electric utilities and the consumers are becoming more and more concerned about the end use of electrical power. Sensitive loads such as computers, PLC, variable speed drives etc. requires high quality supplies.

Innovation and automation of industries involved increasing use of microprocessors, computers and power electronic devices. The power electronic equipments also play a major role in increasing the power quality problem such as harmonics which are generated during faults. The electronic devices are very sensitive to disturbances are becoming intolerant to power quality problems such as voltage sags, swells and harmonics.

3.2 POWER QUALITY PROBLEMS

3. 2.1 Voltage