Sneak Circuits of Power Electronic Converters (eBook)

Bo Zhang, Dongyuan Qiu (Autoren)

eBook Download: EPUB

2014
John Wiley & Sons (Verlag)
978-1-118-37997-4 (ISBN)

Infos

The first treatment of advanced knowledge of electrical sneak circuits and its analysis method in power electronics

 

The work on sneak circuit and its analysis methods for power converters contributes to the reliability of power electronic systems worldwide.  Most books in the subject concentrate on electronic systems, but this book is perhaps the first to examine power electronic systems.  It describes the sneak circuit phenomena in power converters, introduces some SCA methods for power electronic systems and proposes how to eliminate and make use of sneak circuits.  The book is divided into three separate sections.  Firstly, the sneak circuit paths and sneak circuit operating conditions are discussed in different kinds of power converters, including resonant switched capacitor converters, basic DC-DC converters, soft-switching converters and Z-source converters;  Secondly, the sneak circuit analysis guidelines for power converters based on generalized matrix, adjacency matrix and Boolean matrix are presented respectively;  Thirdly, the sneak circuit elimination techniques are introduced and verified in several power converters, with applications of sneak circuits described in conclusion.  Written by a lead author with extensive academic and industrial experience, the book provides a complete introduction and reference to students and professionals alike.

Contents include: Fundamental Concepts, SCA of Resonant Switched Capacitor Converters, SC of DC-DC Converters, SC Analysis Method (including Boolian Matrix), and Applications of SC in Power Converters. 

• Highlights the advanced research works in the sneak circuit analysis, by a leading author in the field
• Original in its treatment of power electronics converters; most other books concentrating on electronics systems, and aimed at both introductory and advanced levels
• Offers guidelines for industry professionals involved in the design of power electronic systems, enabling early detection of potential problems

Essential reading for Graduate students in Electrical Engineering: Engineers and Researchers in Power Electronics

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Sneak Circuits of Power Electronic Converters Sneak Circuits of Power Electronic Converters Work on sneak circuits and related analysis methods for power converters contributes to the reliability of power electronic systems worldwide. Most books on the subject focus on electronic systems; this book is perhaps the first to examine power electronic systems. The authors describe sneak circuit phenomena in power converters, introduce SCA methods for power electronic systems, and propose how to eliminate and make use of sneak circuits. This book: highlights the advanced research works in sneak circuit analysis by a leading author in the field is original in its treatment of power electronics converters, going beyond the electronic system level is suitable for both introductory and advanced levels offers guidelines for industry professionals involved in the design of power electronic systems, enabling early detection of potential problems This book is geared for researchers and graduate students in electrical engineering, as well as engineers and researchers in power electronics. Researchers in power electronics reliability will also find it to be a helpful resource.

Autor

Bo Zhang South China University of Technology, P. R. China. Dongyuan Qiu South China University of Technology, P. R. China.

Inhalt

Chapter 1 Sneak Circuit and Power Electronic System 1

1.1 Reliability of power electronic system 1

1.2 Sneak circuit 3

1.3 Sneak circuit analysis 12

1.4 Power electronic system and sneak circuit analysis 19

1.5 Arrangement of this book 20

References 21

Chapter 2 Sneak Circuits of Resonant Switched CapacitorConverters 23

2.1 Sneak circuits of basic RSC converter 23

2.2 Sneak circuits of high-order RSC converter 47

2.3 Summary 70

References 70

Chapter 3 Sneak Circuits of DC-DC Converters 73

3.1 Buck converter 73

3.2 Boost converter 78

3.3 Buck-boost converter 82

3.4 Sneak circuit conditions of Buck, Boost and Buck-Boostconverters 86

3.5 Cúk converter 88

3.6 Sepic converter 102

3.7 Zeta converter 113

3.8 Sneak circuit conditions of Cúk, Sepic and Zeta converters123

3.9 Summary 125

References 126

Chapter 4 Sneak Circuits of Soft-switching Converters127

4.1 Sneak circuits of Full-bridge ZVS PWM converter 127

4.2 Sneak circuits of Buck ZVS Multi-Resonant converter 149

4.3 Sneak circuits of Buck ZVT PWM converter 157

4.4 Summary 167

References 168

Chapter 5 Sneak Circuits of other Power ElectronicConverters 169

5.1 Sneak circuits of Z-source inverter 169

5.2 Sneak circuits of synchronous DC-DC converters 180

5.3 Summary 191

References 191

Chapter 6 Sneak Circuit Path Analysis Method for PowerElectronic Converters 193

6.1 Basic concepts 193

6.2 Sneak circuit analysis based on adjacency matrix 204

6.3 Sneak circuit analysis based on connection matrix 216

6.4 Sneak circuit analysis based on switching Boolean matrix228

6.5 Comparison of the sneak circuit path analysis methods 240

6.6 Summary 241

References 241

Chapter 7 Sneak Circuit Mode Analysis Method for PowerElectronic Converters 243

7.1 Mesh combination analytical method 244

7.2 Sneak operating unit analytical method 250

7.3 Sneak circuit operating mode analytical method 257

7.4 Results of sneak circuit mode analysis method on Cúkconverter 268

7.5 Summary 269

References 270

Chapter 8 Elimination of Sneak Circuits in Power ElectronicConverters 272

8.1 Sneak circuit elimination for resonant switched capacitorconverters 273

8.2 Sneak circuit elimination for Z-source inverter 280

8.3 Sneak circuit elimination for Buck ZVT PWM converter 285

8.4 Summary 294

References 294

Chapter 9 Application of Sneak Circuits in Power ElectronicConverters 296

9.1 Improvement of power electronic converter based on sneakcircuits 296

9.2 Reconstruction of power electronic converter based on sneakcircuits 307

9.3 New functions of power electronic converter based on sneakcircuits 315

9.4 Fault analysis of power electronic converter based on sneakcircuits 323

9.5 Summary 336

References 336

Textauszug

Chapter 1
Sneak Circuit and Power Electronic Systems

1.1 Reliability of Power Electronic Systems

Power electronics has already found an important place in modern technology, because it helps to meet the demands of energy, particularly in electrical form and efficient use of electricity. Application of power electronics is expanding exponentially in many areas, from computer power supply to industrial motor control, transportation, energy storage, electric power transmission, and distribution. Nowadays, over 70% of electrical loads are supplied through power electronic systems in the United States and Europe, and almost all electrical and electro-mechanical equipment contains power electronic circuits and/or systems. In the next 5 years, renewable energy systems (wind and solar, etc.) will show a sharp increase throughout the world, the needs of power electronic systems grow rapidly as a result. Therefore, the reliability of these systems should be a concern in its fundamental place in energy conversion and management.

A basic concept in reliability engineering is that part failure may cause system failure, and preventing part failure is effective in preventing system failure. Likewise, in power electronic systems, it is found that many system failures do result from component failures. The main factor affecting reliability at part level is the electrical and thermal stress of a component, such as device voltage, current, temperature, or temperature rise due to power dissipation, since the failure rate of the components will double with a 10°C increase in temperature. In order to achieve good reliability, system designers always apply effective reliability assurance techniques, for example, component derating, and thermal and electrical stress analysis, to manage the levels of component voltage, current, and power dissipation, and keep them well within rating limits.

However, not all system failures are caused by component failure. In some situations, no part has failed, yet the system performs improperly or initiates an undesired function. For example, an inadvertent launching of the Redstone rocket on 21 November 1961 resulted from an undetected design error in the electrical path. Such events may cause hazardous and even tragic consequences, which have been proven by many serious accidents in aerospace, navy, nuclear, and military industries in the last century.

A significant cause of such unintended events is named “sneak circuit,” which is the unexpected electrical path or logic flow that can produce an undesired result under certain conditions [1]. Opposed to component failure, a sneak circuit happens without any physical failure in the system, causing an undesired effect in that system, although all parts are working within design specifications.

It is well established in reliability engineering that the more parts there are in a system, the more likely it is to fail. Complexity is considered as the main factor that causes sneak circuit, because it is difficult for the designers to have a complete view of the detailed interrelationship between components and functions in a complex system. As a consequence, sneak circuits may exist in a complex system, and produce undesired results or even prevent intended functions from occurring under certain conditions.

Nowadays, power electronic systems are being designed and manufactured with increased complexity to satisfy specific functions. Similar to other systems, the sneak circuit will affect the reliability of the power electronic system as well as part failure. Therefore, sneak circuit situations in different kinds of power electronic converters should be investigated and identified, which will have a positive impact on the reliability of the power electronic system.

1.2 Sneak Circuit

1.2.1 Definition of Sneak Circuit

A sneak circuit is a designed-in current path or signal flow within a system, which inhibits desired functions or causes unwanted functions to occur without a component having failed. Sneak circuits are not the result of component failures, electrostatic, electromagnetic or leakage factors, marginal parametric factors or slightly out-of-tolerance conditions. They are present but not always active conditions inadvertently designed into the system, coded into the software program, or triggered by human error [2].

Based on the definition of a sneak circuit, the sneak conditions may consist of hardware, software, operator actions, or any combinations of these elements. Thus, sneak circuits are a family of design problems, which includes four categories as follows [1]:

1. Sneak path:

   unexpected path along which current, energy, or logic sequence flows by an unintended route, resulting in unwanted functions or inhibiting a desired function.

2. Sneak timing:

   events occurring in an unexpected or conflicting hardware or logic sequence, which may cause or prevent activation or inhibition of a function at an unexpected time.

3. Sneak indication:

   ambiguous or false display of system operating status that may cause the system or operator to take an undesired action.

4. Sneak label:

   incorrect or imprecise nomenclature or instructions on system inputs, controls, displays, or buses, which may cause the operator to apply an incorrect stimulus to the system.

1.2.2 Examples of Sneak Circuits

Since the 1960s, many accidents in aerospace, navy, nuclear, military, and modern weapon systems, which caused hazardous and even tragic outcomes, have been found to be the result of sneak circuits. In addition, sneak circuits have also existed in household wiring and automobile electrical systems, which did not perform an intended function or initiated an undesired function. Some examples will be introduced in the following section to explain different types of sneak circuits.

1.2.2.1 Automobile Electrical System

Figure 1.1 shows an example of sneak path found in a mid-1960s automobile electrical circuit [1]. The circuitry design meets the electrical system specification, for example, when the ignition switch is on, power is supplied from the battery to the radio, and if the brake switch is closed, the brake lights receive power from the battery. Also, if the hazard switch (pedal) is on and the ignition switch is off, power will be supplied from the battery to the flasher module causing the brake lights to flash. In summary, all of the design intent had been satisfied.

Figure 1.1 An automobile electrical system [1]

However, a problem with this circuit design remains hidden. Assuming that the ignition switch is set to “off,” the radio is switched to “on” and the hazard switch is enabled, if the brake pedal is depressed, power will be applied to turn the radio on with each flash of the brake lights. The cause of this unintended behavior, a sneak path, is highlighted in Figure 1.1. It is the brake switch (pedal) that provides a current path to the radio and places the radio parallel with the brake lights. In this case, the consequences of the sneak path are not severe; children left in the car by their parents could listen to the radio slowly draining the battery.

1.2.2.2 Household Wiring System

A popular household wiring system in Western European is shown in Figure 1.2a, which is a three-phase 127 V/50 Hz system with an approximately balanced load and no neutral return wire. All devices or appliances are connected between lines and operate at 220 V [3]. If the fuse of phase B blows, a sneak path will appear as in Figure 1.2b, leaving devices in line A–B in series with those in line B–C across 220 V line A–C. Then the lamps on circuit A–B will dim if lamps or bath heater on circuit B–C is on and refrigerator operates erratically when the bath heater is on. Though all devices on circuit A–C work normally as before, phase B has no load, and phases A and C have overload, which will cause the distribution transformer to overheat.

Figure 1.2 A household wiring system [3]: (a) normal operating state; and (b) state with broken fuse

1.2.2.3 A Sudden Acceleration Incident

In one kind of US police van, shown in Figure 1.3, the code 3 control switch activates a roof-mounted blue-light bar and causes brake lights and backup lights to pulse alternately at about 2.4 Hz. Diode (D) is used to prevent brake pedal switch from activating the blue-light bar via an alternating flasher relay. On 4 December 1998, an apparent police van shift lock failure combined with suspected misapplication of the accelerator rather than the brake resulted in sudden acceleration, the death of two pedestrians, and injury of nine [4]. It is found that closing code 3 control switch provides a pulsing path (sneak path) through flasher relay and diode D to disengage the shift lock, allowing the vehicle operator to shift into gear while applying the accelerator rather than the brake.

Figure 1.3 Part of control circuit in a police van [3]

1.2.2.4 Redstone Rocket Launch Failure

Figure 1.4a shows the Mercury booster firing circuit of the Redstone rocket [3]. In order to satisfy the launching requirements, the motor is ignited by the on-board fire switch, annunciated by the ignition indicator light through an umbilicus, and the motor ignition coil latches to the on-board power supply (28 V). The on-board motor cutoff coil...

Produkt-Details

• Erscheint lt. Verlag: 31.10.2014
• Reihe/Serie: IEEE Press
• Reihe/Serie: Wiley - IEEE
• Reihe/Serie: Wiley - IEEE
• Sprache: englisch
• Themenwelt: Technik ► Elektrotechnik / Energietechnik
• Schlagworte: Applications of SC in Power Converters • Boolian Matrix • Bo Zhang. Dongyuan Qiu • Circuit Theory & Design / VLSI / ULSI • Electrical & Electronics Engineering • Elektrotechnik u. Elektronik • Energie • Energietechnik • Energy • fundamental concepts • Leistungselektronik • Power Electronics • Power Technology & Power Engineering • SC Analysis Method • SCA of Resonant Switched Capacitor Converters • Schaltkreise - Theorie u. Entwurf / VLSI / ULSI • Schaltkreistechnik • SC of DC-DC Converters • Sneak Circuits of Power Electronic Converters
• ISBN-10: 1-118-37997-7 / 1118379977
• ISBN-13: 978-1-118-37997-4 / 9781118379974