Page 236 - Rashid, Power Electronics Handbook

14

Inverters

Jose  R. Espinoza, Ph.D. 14.1 Introduction ...................................................................................... 225
Depto. Ing. Ele Âctrica, Of. 220 14.2 Single-Phase Voltage Source Inverters .................................................... 227
Universidad de Concepcio Ân 14.2.1 Half-Bridge VSI 14.2.2 Full-Bridge VSI
Casilla 160-C, Correo 3
Concepcio Ân, CHILE 14.3 Three-Phase Voltage Source Inverters..................................................... 235
14.3.1 Sinusoidal PWM 14.3.2 Square-Wave Operation of Three-Phase VSIs
14.3.3 Selective Harmonic Elimination in Three-Phase VSIs 14.3.4 Space-Vector-Based
Modulating Techniques 14.3.5 DC Link Current in Three-Phase VSIs 14.3.6 Load-Phase
Voltages in Three-Phase VSIs
14.4 Current Source Inverters...................................................................... 241
14.4.1 Carrier-based PWM Techniques in CSIs 14.4.2 Square-Wave Operation of Three-
Phase CSIs 14.4.3 Selective Harmonic Elimination in Three-Phase CSIs 14.4.4 Space-
Vector-Based Modulating Techniques in CSIs 14.4.5 DC Link Voltage in Three-Phase CSIs
14.5 Closed-Loop Operation of Inverters ...................................................... 250
14.5.1 Feedforward Techniques in Voltage Source Inverters 14.5.2 Feedforward Techniques
in Current Source Inverters 14.5.3 Feedback Techniques in Voltage Source Inverters
14.5.4 Feedback Techniques in Current Source Inverters
14.6 Regeneration in Inverters ..................................................................... 256
14.6.1 Motoring Operating Mode in Three-Phase VSIs 14.6.2 Regenerative Operating Mode
in Three-Phase VSIs 14.6.3 Regenerative Operating Mode in Three-Phase CSIs
14.7 Multistage Inverters............................................................................. 260
14.7.1 Multicell Topologies 14.7.2 Multilevel Topologies
14.8 Acknowledgments............................................................................... 267
References.......................................................................................... 267

14.1 Introduction naturally behave as voltage sources as required by many
industrial applications, such as adjustable speed drives
The main objective of static power converters is to produce an (ASDs), which are the most popular application of inverters;
ac output waveform from a dc power supply. These are the see Fig. 14.1a. Similarly, these topologies can be found as
types of waveforms required in adjustable speed drives current source inverters (CSIs), where the independently
(ASDs), uninterruptible power supplies (UPS), static var controlled ac output is a current waveform. These structures
compensators, active ®lters, ¯exible ac transmission systems are still widely used in medium-voltage industrial applications,
(FACTS), and voltage compensators, which are only a few where high-quality voltage waveforms are required.
applications. For sinusoidal ac outputs, the magnitude, Static power converters, speci®cally inverters, are
frequency, and phase should be controllable. According to constructed from power switches and the ac output waveforms
the type of ac output waveform, these topologies can be are therefore made up of discrete values. This leads to the
considered as voltage source inverters (VSIs), where the generation of waveforms that feature fast transitions rather
independently controlled ac output is a voltage waveform. than smooth ones. For instance, the ac output voltage
These structures are the most widely used because they produced by the VSI of a standard ASD is a three-level

225
Copyright # 2001 by Academic Press.
All rights of reproduction in any form reserved.