Energy Saving and Power Factor Improvement

In an ideal a.c. power system, the voltage and frequency at every supply point would be the constant and free from harmonics, and the power factor would be unity. Most Industrial loads have lagging power factors. That is they absorb reactive power. The load current therefore tends to be larger than is required to supply the real power alone. Only the real power is ultimately useful in energy conversion and the excess load current represents a waste to the consumer, who has to pay not only for the excess cable capacity to carry it but also for the excess joule loss produced in the supply cables.

The supply utilities also have good reasons for not transmitting unnecessary reactive power from generators to loads. Their generators and distribution networks cannot be used at full efficiency, and the control of voltage in the supply system can become more difficult. Supply tariffs to industrial consumers almost always penalize low power factor loads.

It is much more practical and economical to size the power system according to the maximum demand for real power, and to manage the reactive power by means of compensators and other equipment which can be deployed more flexible than generating units and which make no contribution to fault levels.

Most a.c. power systems are three-phases, and are designed for balanced operation. Unbalanced operation gives rise to components of current in the wrong phase sequence (i.e. negative and zero sequence components). Such components can have undesirable effects, including additional losses in motor and generator units, oscillating torque in a.c. machines, increased ripple reactive in rectifier, malfunctions of several types of equipment, saturation of transformers, and excessive neutral currents. The load compensation improves the phase balancing and power factor correction of unsymmetrical loads. Many utilities need this particular course, which cover the illustration of main concepts of reactive power management using actual case studies.

Course Objectives

Towards the end of the training, the participants will be able to:

Understand the basics of reactive power and power factor. Understanding main concepts of management of active and reactive power Know the importance of power factor improvement and its deferent methods How to improve the quality of supply in a.c. power system. Know how to calculate manually by hand the different techniques for power factor improvement. How to use the generators, distribution networks, and equipment at full efficiency. To get familiar with capacitors, their structure and their ability to improve the power factor. Study of capacitors installation locations in high voltage, medium voltage and low voltage networks. Solving capacitors problems, and capacitors maintenance. Familiar with different applications of capacitors in high voltage, medium voltage and low voltage networks. Know what is Static VAR Compensators: construction, types and control methods. To get familiar with Static VAR Compensator applications in power systems (high and medium tension) To know how to select, calculate, connect the reactive power compensator to improve the power factor, the voltage regulation and the load balancing in the utilities and industrial networks. To know the problems appear due to use compensation equipment and how to mitigate those problems.

Course Outline

DAY ONE

SECTION 1: CONDUCTING AN ENERGY AUDIT

• INTRODUCTION

• SOURCES OF ENERGY

• WHAT IS AN ENERGY AUDIT?

• ENERGY AUDIT PROGRAMS

• BENEFITS OF ENERGY AUDIT

• ENERGY AUDIT APPROACH

• ENERGY AUDIT CHARACTERISTICS

• Worksheet (1)

SECTION 2: BASIC CONCEPTS

• Alternating Current Circuits

• Instantaneous Power (p)

• Complex Power

• Power Triangle

• Power Factor

• Capacitor Construction and Operation

• Loss Angle or Tan d

• Exercises: Power Calculations of Loads

• Do It Yourself

DAY TWO

SECTION 3: POWER FACTOR IMPROVEMENT – GENERAL

• Introduction

• Causes of low power factors

• Known loads power factors

• Annual power factor penalty

• Unfavorable effects of low power factor loads

• Capacitor price simple payback

• Power factor improvement

• Capacitor sizing

• Economic considerations of power factor improvement

• Power analyzer

SECTION 4: INDUSTRIAL APPLICATION OF CAPACITORS

• Introduction

• Power Factor Improvement for Power Transformer

• Power Factor Improvement for Induction Motors

• Automatic Control of Capacitors

• Steps and Stage Size Considerations

• Microprocessor controlled capacitor

• Harmonics and harmonic filters

• Power Factor Improvements for Welding Plant and Arc Furnaces

DAY THREE

SECTION 5: CAPACITOR LOCATION, INSTALLATION AND PROTECTION

• Capacitor Location

• Capacitor Installation

• Making a Capacitor Element

• Making Capacitor Unit From Elements

• Making Capacitor Banks From Capacitor Units

• Capacitor Fusing

• Precautions Against Overvoltages on the Failure of Some Units

• Capacitance Unbalance Detection

• Over Current and Short Circuit Protection

• Protection of Series Capacitors

• Capacitor Operation Problems and Solutions

• Checking Capacitor Banks for Failed Capacitors

• Test Requirements

• Capacitor Maintenance

DAY FOUR

SECTION 6: APPLICATION OF POWER CAPACITOR IN POWER SYSTEM

• Effects of Capacitors on Power Supply Circuits

• Application of Shunt Capacitors to Power Supply Systems

• Application of Series Capacitors to Power Supply Systems

• SCADA Controlled Multi-Step Automatic Controlled Capacitor Banks & Filter Banks

• Applications

DAY FIVE

SECTION 7: SVC AND REACTIVE POWER CONTROL

• Introduction

• Reactors

• What Are Static VAR Compensators?

• Types of Static VAR Compensators

• Basis of Selection of Compensator Type

• Static VAR Compensators Thyristors

• SVC's Control Technique

• Applications of SVC

• Design of SVC Parameters

Course Methodology

A variety of methodologies will be used during the course that includes:

• (30%) Based on Case Studies

• (30%) Techniques

• (30%) Role Play

• (10%) Concepts

• Pre-test and Post-test

• Variety of Learning Methods

• Lectures

• Case Studies and Self Questionaires

• Group Work

• Discussion

• Presentation