Pulsewidth Modulated DC-to-DC Power Conversion: Circuits, Dynamics, and Control Designs provides engineers, researchers, and students in the power electronics field with comprehensive and complete guidance to understanding pulsewidth modulated (PWM) DC-to-DC power converters. Presented in three parts, the book addresses the circuitry and operation of PWM DC-to-DC converters and their dynamic characteristics, along with in-depth discussions of control design of PWM DC-to-DC converters. Topics include:
Pulse width Modulated DC DC Power Converters
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_OC_InitNavbar("child_node":["title":"My library","url":" =114584440181414684107\u0026source=gbs_lp_bookshelf_list","id":"my_library","collapsed":true,"title":"My History","url":"","id":"my_history","collapsed":true,"title":"Books on Google Play","url":" ","id":"ebookstore","collapsed":true],"highlighted_node_id":"");Pulsewidth Modulated DC-to-DC Power Conversion: Circuits, Dynamics, and Control DesignsByungcho ChoiWiley, 30 Jul 2013 - Technology & Engineering - 664 pages 0 ReviewsReviews aren't verified, but Google checks for and removes fake content when it's identifiedThis is the definitive reference for anyone involved in pulsewidth modulated DC-to-DC power conversion
Pulsewidth Modulated DC-to-DC Power Conversion: Circuits, Dynamics, and Control Designs provides engineers, researchers, and students in the power electronics field with comprehensive and complete guidance to understanding pulsewidth modulated (PWM) DC-to-DC power converters. Presented in three parts, the book addresses the circuitry and operation of PWM DC-to-DC converters and their dynamic characteristics, along with in-depth discussions of control design of PWM DC-to-DC converters. Topics include:
The LT-4X (Series) is a pulse width-modulated DC to DC converter that provides regulated output power. This converter transforms an unregulated 28 VDC to regulated output power. The output voltage is adjusted via a remote control rheostat 5K ohm 1/2 W to ground. Fixed output and voltage control models are also available.
The LT-4X (Series) is primarily designed to control the light intensity of incandescent bulbs in aircraft lighting. The LT-4X (Series) are qualified to the FAA technical standards order (TSO-C71) for airborne static DC-DC electrical power converters.
The authors describe a novel pulse-width modulator with feedforward compensation of input voltage disturbances in boost DC-DC switched mode power converters. The modulator transforms an open-loop boost converter into a linear DC voltage amplifier. It is suitable for simple integrated-circuit implementation using the same building blocks as existing PWM (pulsed width modulation) controllers for switched mode power supplies.
The VLC driver is a key element of VLC systems because it is in charge of supplying the HB-LEDs properly to obtain the desired s(t). In order to achieve that target, the output voltage of the VLC driver [vo(t)] is also made up of a DC component (Vo-dc) and an AC component [vo-ac(t)] that determine Sdc and sac(t), respectively. It is important to note that although conventional HB-LED drivers for lighting applications are able to reach high power efficiency [5], the communication functionality of VLC drivers adds extra power losses, thus reducing the overall system efficiency [6]. The reason is that, in contrast to conventional HB-LED drivers for lighting applications, a VLC driver has to provide not only high-power efficiency, but also high bandwidth and linearity to fulfill the transmission capability [7]. As a consequence, a lot of research efforts during the last years have been made to alleviate that trade-off [8].
In contrast to LPAs, Switching-Mode Power Amplifiers (SMPAs) reach high power efficiency (the theoretical power efficiency is 100%) because the employed transistors operate as electronic switches instead of operating in linear mode. Therefore, the LPA of the VLC driver shown in Figure 1 could be replaced by a SMPA in order to alleviate the power efficiency problem. In this sense, previous works explored the use of Class E SMPAs [14,15]. Unfortunately, that SMPA class is not able to modulate the amplitude of the communication carrier and, consequently, that approach only allows us to reproduce phase-modulated schemes. Moreover, the Class E SMPA suffers from high voltage stresses across the switches and low slew-rates. In this sense, the use of a LPA that linearly assists the Class E SMPA was proposed to increase the slew-rate [14]. However, that LPA also damages the power efficiency and increases the complexity of the VLC driver. Furthermore, it does not solve the limitation related to the reproduction of amplitude-modulated schemes. Alternatively, two VLC drivers based on the use of Class E SMPAs can be combined to reproduce amplitude-modulated schemes by implementing the outphasing technique [15]. Unfortunately, that approach leads to high complexity in terms of both hardware and control, which are critical parameters to be consider for designing HB-LED bulbs [16].
As can be seen, the modulation strategy consists in generating a pulse-pattern with constant-frequency where the pulse width determines the output voltage (see Figure 4a). After that, the undesired harmonics are removed by the filter (see Figure 4b). In this modulation strategy, the frequency of the pulse-voltage waveform (fs), which is called switching frequency, must be much higher than the frequency of the sinusoidal signal that is used as communication carrier (i.e., f0) in order to achieve enough rejection of the undesired harmonics (typically, fs > 10f0).
Figure 5 shows the main voltage waveforms necessary to understand the operation of a RF-PWM Class D SMPA. In this case, the filter passes the fundamental harmonic of vs(t) (i.e., the harmonic at fs), which is used as communication carrier (see Figure 5b). Moreover, the technique is based on controlling not only the pulse width, but also the pulse position in order to perform the amplitude and phase modulation of the communication carrier, respectively. In particular, the dimensionless control parameters d(t) and γ(t) are used to control the pulse width and the pulse position, respectively (see Figure 5a). It is important to note that d(t) ranges between 0 and 0.5, and γ(t) ranges between 0 and 1.
Another important point that must be taken into account when choosing L and C values is that the amplitudes of the undesired harmonics change as the pulse width is modulated [see Equation (1)]. In particular, the amplitude modulation of the kth harmonic of vs(t) can be expressed as follows:
Analysis of the pulse-width modulation impact on the harmonics amplitudes: (a) Amplitude modulation of each harmonic versus d(t). (b) Ratio between the amplitudes of the first and the second harmonic.
Abstract: Featured ApplicationProvide a robust-control design technique for pulse-width-modulated power converters in continuous conduction mode using low-cost analog circuits. AbstractIn this paper, a simplified double-integral sliding-mode control method for pulse-width-modulated dc-ac buck conversion is introduced. The control equation is derived based on the equivalent control method, in which the control-oriented model is developed using the averaged dynamics of the power converter in continuous conduction mode. In contrast with the conventional sliding-mode control schemes, the complexity of adding a capacitor current sensor, variable ramp voltage, and other relevant components is avoided. Furthermore, the control equation is translated into a simple electronic circuit with minimal added components, which reduces the practical implementation cost. The proposed control method rejects large disturbances, tracks the reference signal, and maintains a constant switching frequency. Systematic design procedure, control parameters selection, and stability conditions are presented. The design methodology is verified via simulating the proposed control circuit using Simscape Electrical in MATLAB. The control method is also compared with the conventional double-integral sliding-mode control scheme under load disturbances. The results show that the simplified control approach provides a fast transient response and robust tracking performance.Keywords: analog control circuit; constant switching frequency; dc-ac buck converter; double-integral sliding-mode control; pulse-width modulation
Pulse-width Modulated DC-DC Power Converters is a comprehensive textbook for senior undergraduate and graduate students in the areas of electrical, electronics, and telecommunications engineering. It includes end-of-chapter review questions, problems, and thorough summaries of the key concepts to aid learning, and a Solutions Manual is available for professors. Scientists and practicing design engineers working with SMPS, within such applications as computers, telecommunications, industrial systems, automobile electronics, medical equipment, aerospace power technology, and radars (amongst others) will also find this text insightful.
A method for generating pulse width modulated control signal has the steps of providing a base carrier waveform, segmenting the base carrier waveform into a plurality of carrier waveforms, and providing at least one modulating signal. The first and second waveforms are compared to the at least one modulating signal to produce first and second comparator outputs, which are then mathematically combined to produce a pulse width modulated control signal. 2ff7e9595c
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