Measuring Power Quality Of A System

ABSTRACT

Electrical energy is a traded commodity that is becoming more important every day; there is increasing demand for continuous access to power (supply quality) and disturbance free power (power quality). Today’s power environments cover renewable energy production as well as continuously increasing electrical demand within the home and industrial sectors. This increases the requirement for continuous and reliable monitoring of the power consumed. Each disturbance that occurs reduces the quality of delivery and power and thereby gives an increased cost. Energy optimization covers both checks of energy volume as well as a connection to energy losses and their cause. Supplementing energy measurement with power quality measurement gives the information to display the cause of energy losses. Then a decision for the most cost efficient action can be made. power quality gives you the foundation to optimize your power and transmission network and make cost savings.

TABLE OF CONTENTS

 TITLE PAGE

APPROVAL PAGE

DEDICATION

ACKNOWELDGEMENT

ABSTRACT

DEFINITION OF TERMS

TABLE OF CONTENT

CHAPTER ONE

• INTRODUCTION
• OBJECTIVE OF THE PROJECT
• PURPOSE OF THE PROJECT
• SIGNIFICANCE OF THE PROJECT
• SCOPE OF THE PTOJECT
• BENEFIT OF MEASURING POWER QUALITY IN A SYSTEM
• CAUSES OF POWER QUALITY PROBLEM
• EFFECT OF POWER QUALITY PROBLEMS
• POWER QUALITY DISTURBANCES

CHAPTER TWO

LITERATURE REVIEW

2.0      LITERATURE REVIEW

2.1      OVERVIEW OF THE STUDY

2.2     NEED FOR COMPENSATION

2.3     TYPES OF COMPENSATION

2.4    OVERVIEW OF STATCOM AND ITS USES

2.5     APPLICATIONS OF STATCOMS

2.5    DETERMINING THE BEST FOUNDATION

CHAPTER THREE

DESIGN METHODOLOGY

3.1      METHODOLOGY

3.2      DESIGN OF STATCOM

3.3      MODELLING OF STATCOM

3.4      OPERATION OF STATCOM

CHAPTER FOUR

RESULT ANALYSIS

4.1 RESULT

4.2 POWER FACTOR COMPARISION

CHAPTER FIVE

5.0      CONCLUSION AND REFERENCES

• CONCLUSION

5.2     REFERENCES

CHAPTER

1.0                                                      INTRODUCTION

The aim of the power system has always been to supply electrical energy to customers. Earlier the consumers of electrical energy were mere acceptors. Interruptions and other voltage disturbances were part of the deal. But today electric power is viewed as a product with certain characteristics which can be measured, predicted, guaranteed, improved etc. Moreover it has become an integral part of our life. So the quality of the power supply has gained much importance. The term ‘power quality’ emerged as a result of this new emphasis placed on the customer utility relationship. The fact that power quality has become an issue recently does not mean that it was not important in the past. Utilities all over the world have for decades worked on the improvement of what is now known as power quality. In the recent years, users of electric power have detected an increasing number of drawbacks caused by electric power quality variations. These variations already existed on the electrical system but only recently they are causing serious problems. This is due to the increased sensitivity of equipments and devices used by customers. These end user equipments are more interconnected in networks and industrial processes, that the impact of a problem with any piece of equipment is much more severe. Also power quality of power systems affects all connected electrical and electronic equipments and is a measure of deviations in voltage, current, frequency, temperature, force, and torque of particular supply systems and their components. To fulfill the demand of required supply, the world is under tremendous pressure for alternative sources of energy and has been inclined towards sustainable energy for future source of energy. The energy sources like solar energy, wind energy, hydroelectric power, tidal power, geothermal power and wave power are all important types of renewable energy. However if these energy sources are coupled with the energy efficacy it is termed as sustainable energy sources. Sustainable Energy is the provision of energy such that it meets the needs of the future without compromising the ability of future generations to meet their own needs. It is required to have more efficient means of converting and utilizing these energy. This will depend on the quality of power supplied and the impact of end user equipments on that power. But power electronic equipments are mostly used in sustainable and renewable energies in different stages for acquisition and conversion or inversion into useable form. Due to increasing sensitivity of the equipments and devices used by the customers, power qualities of sustainable energy are affected. Poor Power Quality results in high costs and that is gradually rising. The poorer the Power Quality, the more would be the initiatives required from concerned parties and regulating bodies to adopt corrective measures to ensure better Power Quality. As a consequence, the economy of a country is largely affected with even low tech industries suffering serious financial losses. Especially for successful sustainable energy programe, Power Quality Monitoring can help identify the cause of power system disturbances and the underlying problem conditions on a system before they cause interruptions and disturbances. Due to this many power utilities perform power quality monitoring as an essential service for their main customers. Essential capabilities of a power quality monitoring system are reduced cost and remote data transmission capability. With the electrical industry undergoing change, increased attention is being focused on reliability and power quality. Power providers and users alike are concerned about reliable power, whether the focus is on interruptions and disturbances or harmonic distortion or flicker. One of the most critical steps in ensuring reliability is monitoring power quality. Power quality monitoring can help to identify the cause of power system disturbances and even help to identify problem conditions before they cause interruptions or disturbances. Hence power quality monitoring is a multi-pronged approach to identifying, analyzing, and correcting power quality problems. To improve power quality with adequate solutions, it is necessary to know what kinds of disturbances occurred. A power quality monitoring system that is able to automatically detect, characterize and classify disturbances on electrical lines is therefore required. With power quality monitoring, power engineers can eliminate some of their troubleshooting headaches.

1.2                                          OBJECTIVE OF THE PROJECT

The objective of Power quality measurement is to supply power that is free of disturbance. Today, the greater part of all electrical equipment is built up of electronics that not only create disturbances on the power and transmission network but are also more sensitive to poorer power quality than traditional electrical apparatus.

Electrical disturbances occur at everything from planned to unplanned events on the power and transmission network. Examples of causes of power quality problems are; connections in the power and transmission network, connection and disconnection of electrical loads, lightning strikes, disturbing electrical apparatus (switched power supplies, frequency inverters, low energy light bulbs etc.), weak power and transmission networks and variable power production (renewable power production, wind power etc.)

1.3                                          SIGINIFICANCE OF THE STUDY

Power quality measurement is an essential service many utilities perform for their industrial and key customers. Because of the technology and software now available, this measurement is a highly-effective means to detect, solve, and even prevent problems on both utility and customer power systems. Not only can a monitoring system provide information about system disturbances and their possible causes, it can also detect problem conditions throughout the system before they cause customer complaints, equipment malfunctions, and even equipment damage or failure. Power quality problems are not necessarily limited to the utility side of the system – indeed, surveys have shown that the majority of power quality problems are localized within customer facilities. Given this, power quality measurement is not only an effective customer service strategy, but also a way to protect a utility’s reputation for quality power and service. In an industry facing increased competition, this reputation can be the difference between keeping and losing key accounts.

1.4                                          PURPOSE OF THE STUDY

Electrical energy is a traded commodity that is becoming more important every day; there is increasing demand for continuous access to power (supply quality) and disturbance free power (power quality). Today’s power environments cover renewable energy production as well as continuously increasing electrical demand within the home and industrial sectors. This increases the requirement for continuous and reliable monitoring of the power consumed. Each disturbance that occurs reduces the quality of delivery and power and thereby gives an increased cost. Energy optimization covers both checks of energy volume as well as a connection to energy losses and their cause. Power quality measurement gives the information to display the cause of energy losses. Then a decision for the most cost efficient action can be made. Measuring power quality gives you the foundation to optimize your power and transmission network and make cost savings.

1.5                  BENEFIT OF MEASURING POWER QUALITY IN A SYSTEM

Benefits of a power quality measurement are:

1. Assist in preventive and predictive maintenance
2. Identify source and frequency of events
3. Establish precise location and timing of events
4. Develop maintenance schedules based on power quality trends
5. Determine the need for mitigation equipment
6. Monitor and trend conditions
7. Analyze harmonics, voltage sag, power factor correction
8. Make decisions based on documented trends
9. Ensure equipment performance
10. UPS and backup systems
11. Power quality mitigation
12. Assess sensitivity of process equipment to disturbances
13. Evaluate performance against specifications
14. Compare current and voltage
15. Benchmark overall system performance
16. Make multi-site comparisons
17. Energy rate comparisons
18. Improve energy rates
19. Identify load versus demand
20. Conduct energy curtailment analysis
21. Evaluate alternative rate structures

1.6                              CAUSES OF POWER QUALITY PROBLEMS

The causes of power quality problems can be many. It is often difficult to point an exact cause for a specific problem. Power quality measuring equipments comes to aid in such situations. Most of the causes of power quality problem can be divided into two categories:

Internal: This cause approximately 80% of electrical problems originate within a business facility. Potential culprits may include large equipments start or shut down, improper wiring and grounding, overloaded circuits or harmonics.

External: This cause about 20% of power quality problems originate with the utility transmission and distribution system .The most common cause is a lightning strike; other possibilities include equipments failure, vehicle accidents, weather conditions, neighboring business and even normal operation of utility equipments.

1.7                                          POWER QUALITY DISTURBANCES

Power quality is concerned with the deviation of the voltage from the ideal waveform or the deviation of the current from the ideal waveform. Such a deviation is called a power quality phenomena or disturbances. It is important to first understand the kinds of power quality disturbances that can cause problems with the sensitive loads. Categories of these disturbances must be developed with a consistent set of definitions, so that the measurement equipments can be designed in a consistent manner. Power quality phenomena can be divided into two basis categories. Steady state variations A characteristic of voltage or current is never exactly equal to its nominal or desired value. The small deviations from the desired value are called voltage or current variations. A property of any variation is that it has value at any moment in time. Monitoring of variations thus has to take place continuously. Events Occasionally, the voltage or current deviates significantly from the nominal or ideal wave shape. These sudden deviations are called events. Monitoring of events take place by using a triggering mechanism where recording of voltage or current starts the moment, a threshold is exceeded.