Enhanced Phase-Locked Loop Structures for Power and Energy Applications

Masoud Karimi-Ghartema

• Publisher: Wiley-IEEE Press
• Year: 2014
• Print ISBN: 9781118795026
• eBook ISBN: 9781118795132
• Edition: 1
• Topic: Technology & Engineering
• Subtopic: Electrical Engineering & Telecommunications
• Index: Technology & Engineering

Filling the gap in the market dedicated to PLL structures for power systems

Internationally recognized expert Dr. Masoud Karimi-Ghartemani brings over twenty years of experience working with PLL structures to Enhanced Phase-Locked Loop Structures for Power and Energy Applications, the only book on the market specifically dedicated to PLL architectures as they apply to power engineering. As technology has grown and spread to new devices, PLL has increased in significance for power systems and the devices that connect with the power grid. This book discusses the PLL structures that are directly applicable to power systems using simple language, making it easily digestible for a wide audience of engineers, technicians, and graduate students.

Enhanced phase-locked loop (EPLL) has become the most widely utilized architecture over the past decade, and many books lack explanation of the structural differences between PLL and EPLL. This book discusses those differences and also provides detailed instructions on using EPLL for both single-phase applications and three-phase applications. The book's major topics include:

• A basic look at PLL and its standard structure
• A full explanation of EPLL
• EPLL extensions and modifications
• Digital implementation of EPLL
• Extensions of EPLL to three-phase structures

Dr. Karimi-Ghartemani provides basic analysis that helps readers understand each of the structures presented without requiring complicated mathematical proofs. His book is filled with illustrated examples and simulations that connect theory to the real world, making Enhanced Phase-Locked Loop Structures for Power and Energy Applications an ideal reference for anyone working with inverters, rectifiers, and related technologies.

I
PLL Structures for Single-Phase Applications

Part I of this text presents a comprehensive study of single-phase phase-locked loop (PLL) structures. Chapter 1 provides an overview of the standard PLL structure and explains its shortcomings with regard to power engineering applications. The concept of enhanced PLL (EPLL) is introduced in Chapter 2, and its suitability for power engineering applications is demonstrated. Chapter 3 presents various modifications and extensions to the basic EPLL structure in order to address different issues and to make it work for different applications. Details of digital implementation of EPLL structures are studied in Chapter 4. The integrated synchronization and control (ISC) concept for the operation of power electronic DC/AC converters is introduced and discussed in Chapter 5.

1
PLL Basics and Standard Structure

This chapter provides an overview of the standard phase-locked loop (PLL) structure and illustrates that this structure is not suitable for power engineering applications. The large double-frequency ripples in the PLL cause errors beyond admissible limits of many power engineering applications. Attempts to reduce such errors by means of linear filters bring about long transient response times inadmissible for similar applications.

1.1 Standard PLL Structure

Structure of a standard PLL is shown in Figure 1.1 [5, 25, 31, 59]. The input signal is denoted by u(t), LF stands for loop filter, and VCO stands for voltage-controlled oscillator. The input signal is multiplied with the VCO’s output signal y, is passed through the LF, and the outcome is applied to the VCO.

FIGURE 1.1 Structure of a standard PLL.

The VCO generates a sinusoidal signal whose phase angle is proportional to the integral of the VCO’s input. The VCO has a center frequency ω_n, and the relationship between its output signal phase angle and the input signal is given by

(1.1)

where ω_o = ω_n + Δω_o is the estimated frequency and Δω_o represents the deviation of frequency from the center frequency ω_n.¹ The VCO’s operation can be modeled as an integration and a trigonometric function as shown in Figure 1.2. The center frequency for the VCO is equal to the nominal value of the input signal frequency.

FIGURE 1.2 Two recommended ...

Table of contents

• Cover
• Series page
• Title page
• Copyright page
• Dedication
• Preface
• Acknowledgments
• Acronyms
• Symbols
• Introduction
• I: PLL Structures for Single-Phase Applications
• II: Pll Structures for Three-Phase Applications
• References
• Index
• Ieee Press Series on Microelectronic Systems
• End User License Agreement