Book

Pulse Width Modulation for Power Converters : Principles and Practice

11/2003; ISBN: 0471208140
Source: IEEE Xplore

ABSTRACT An integrated and comprehensive theory of PWM The selection of the best algorithm for optimum pulse width modulation is an important process that can result in improved converter efficiency, better load (motor) efficiency, and reduced electromagnetic interference. However, the identification of the best approach is a complex process requiring extensive mathematical manipulation. Pulse Width Modulation for Power Converters: Principles and Practice is the first single-volume resource written to help researchers in the field attain a working knowledge of the subject. The authors bring together today’s seemingly diverse approaches into a single integrated and comprehensive theory of modulation. The book provides a generalized approach to the fundamentals of PWM, looking at:
Active switch pulse width determination
Active switch pulse placement within a switching period
Active switch pulse sequence between phase legs and across switching periods
The main benefit of this generalized concept is that once the common threads are identified, the selection of a modulation strategy for any converter topology becomes immediately clear, leaving only secondary factors, such as practical performance, cost, and difficulty of implementation to consider. Additionally, it allows the performance of any particular converter topology and PWM strategy to be quickly and easily identified without complex and time-consuming analysis. Pulse Width Modulation for Power Converters: Principles and Practice enables the reader to achieve optimum PWM results for any application.

0 0
 · 
5 Bookmarks
 · 
327 Views
  • Source
    [show abstract] [hide abstract]
    ABSTRACT: The Z-source inverter is an alternative power conversion topology that can both buck and boost the input voltage using passive components. With its unique structure, Z-source inverter can utilize the shoot through states to boost the output voltage, which improves the inverter reliability greatly, and provides an attractive single stage dc to ac conversion that is able to buck and boost the voltage. The shoot-through duty cycle is used for controlling the dc link voltage boost and hence the output voltage boost of the inverter. This paper focuses on step by step development of MATLAB/SIMULINK model of Z-source inverter followed by their harmonics study as compared to traditional inverters i.e. voltage and current source inverter. Analysis and simulation results will be presented to demonstrate that it reduces harmonics, electromagnetic interference noise and it has low common made noise. Index Terms -Shoot-through states, simulation, duty cycle and Z-source inverter.
    Global Journal of Advanced Engineering Technologies. 01/2012;
  • Source
    [show abstract] [hide abstract]
    ABSTRACT: This paper describes the design procedure and performance of an LCL grid filter for a medium-voltage neutral-point clamped converter to be adopted for a multimegawatt (multi-MW) wind turbine. The unique filter design challenges in this application are driven by a combination of the medium-voltage converter, a limited allowable switching frequency, component physical size and weight concerns, and the stringent limits for allowable injected current harmonics. Traditional design procedures of grid filters for lower power and higher switching frequency converters are not valid for a multi-MW filter connecting a medium-voltage converter switching at low frequency to the electric grid. This paper demonstrates a frequency-domain-model-based approach to determine the optimum filter parameters that provide the necessary performance under all operating conditions given the necessary design constraints. To achieve this goal, new concepts, such as virtual-harmonic content and virtual filter losses are introduced. Moreover, a new passive-damping technique that provides the necessary damping with low losses and very little degradation of the high-frequency attenuation is proposed.
    IEEE Transactions on Industrial Electronics 05/2011; · 5.17 Impact Factor
  • Source
    [show abstract] [hide abstract]
    ABSTRACT: Control and modulation schemes for ac electrical drives synthesize switched three-phase voltage waveforms that control the electrical machine. Particularly in medium-voltage applications, the aim is to minimize both the switching losses in the inverter and the harmonic distortions of the stator currents and the torque. For a given modulation scheme, lower switching losses usually imply higher distortion factors and vice versa. This tradeoff can be described by a hyperbolic function, as shown in this paper for pulsewidth modulation (PWM). A number of predictive control concepts are rapidly emerging. Their characteristic hyperbolic tradeoff functions are derived, compared with each other, and benchmarked with respect to PWM and offline optimized pulse patterns (OPPs). It is shown that predictive schemes with long prediction horizons shift the performance tradeoff curve toward the origin, thus lowering both the switching losses and the harmonic distortions. As a result, at steady-state operating conditions, these predictive schemes achieve a performance similar to OPPs, while providing a superior dynamic performance during transients.
    IEEE Transactions on Industry Applications 07/2011; · 1.67 Impact Factor