Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 30 for “"Control Bandwidth"”.
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Digital Control of a High Frequency Parallel Resonant DC-DC Converter
… is modeled and a reference classical analog controller is designed and simulated. Infrastructure required for digital control of the converter (including anti-aliasing filters and a modulator) is designed and a classical digital controller is designed and simulated, yielding a ~30% …
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Stability Methods for Regulated Loads
… system, an equivalent circuit model for limited-bandwidth CPLs is presented. This model quantifies the intrinsic damping properties of regulated converters and how they relate to the control bandwidth. A control architecture based on this equivalent circuit model is then analyzed. The control …
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Fine surface control of flexible space mirrors using adaptive optics and robust control
… flexible, segmented mirrors. Traditional control approaches for mirror alignment and shape control may be inadequate due to flexibilities and low natural frequencies. Using adaptive optics for space telescopes presents a possible solution. This research proposes innovative H[infinity] …
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Modeling and Implementation of Controller for Switched Reluctance Motor With Ac Small Signal Model
As traditional control schemes, open-loop Hysteresis and closed-loop pulse-width-modulation (PWM) have been used for the switched reluctance motor (SRM) current controller. The Hysteresis controller induces large unpleasant audible noises because it needs to vary the switching frequency to maintain …
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Design and Control of Quasi-direct Drive Actuation for Lightweight and Versatile Wearable Robots
… of robotics. Furthermore, the design and control are still considered to be grand challenges for providing physical augmentation for humans. In terms of design, the state-of-the-art exoskeletons are typically rigid, bulky, and limited to lab settings. In terms of control, most of the …
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Highly parallelized control programming methodologies using multicore CPU and FPGA for highly dynamic multi-DoF mobile robots, applied to the MIT Cheetah
This thesis presents highly parallelized control programming methodologies developed for multi-degrees of freedom (DoF) robots capable of highly dynamic movements. In robotic applications that require rapid physical interactions with the environment, it is critical for the robot to achieve a …
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Hybrid Active Power Filter with Output Impedance Control
… use active filters to more-seamlessly extend the control bandwidth of today's VRM technology. A hybrid active power filter is developed which uses bipolar junction transistors (BJT) in the forward-active region to connect a power supply source to the microprocessor. In this way, the switches are …
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Study on Bandgap Manipulation and Structural Vibration Control in Sandwich Metastructures
… used, they still face limitations in broadband control of medium- and low-frequency vibrations, particularly in terms of effective bandwidth and robustness to parameter variations and changing operating conditions. In recent years, inspired by advances in acoustic and mechanical metamaterials, …
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Implementation and Validation of Network Policy Services
… to protect and guarantee QoS elements such as bandwidth, delay and jitter to mission critical applications. At the networking level, QoS can be provided using Differentiated services, integrated services or some other mechanisms. Policy based networking provides the network administrator with …
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Modular Hopping and Running via Parallel Composition
… planar hopping using a composition of ``parts'': controlled vertical hopping, controlled forward speed, and controlled body attitude. Such reduced degree-of-freedom compositions also seem to appear in running animals across several orders of magnitude of scale. Dynamical systems theory can offer a …
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Control Strategies for High Power Four-Leg Voltage Source Inverters
… some of the causes of poor power quality and control strategies to ensure a high performance level in inverter-fed power systems. In particular, specific loading conditions present interesting challenges to inverter-fed, high power systems. No-load, unbalanced loading, and non-linear loading …
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High Performance Power Converter Systems for Nonlinear and Unbalanced Load/Source
… in the d-q-o rotating coordinates. Voltage control loops are designed in the d-q-o coordinates for a high power utility power supply. Performance is studied under various load conditions. At the power converter system level, the load conditioner concept is proposed for high power …
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Implementation of a 100kW Soft-Switched DC Bus Regulator Based on Power Electronics Building Block Concept
… overall efficiency. PEBB modules and a digital control building block are the subsystems of the DC bus regulator. This thesis addresses the design issues at subsystem and system levels. These include: operational principles and design of ZCT PEBB modules; design and implementation of the digital …
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Equivalent Circuit Model for Current Mode Controls and Its Extensions
Current-mode control architectures have been an indispensable technique in many applications, such as Voltage Regulator, Point-of-load converters, power factor correction, battery charger and LED driver. Since the inductor current ramp is used in the modulator in current-mode control without any …
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High Frequency, High Current Integrated Magnetics Design and Analysis
… is to increase the switching frequency and control bandwidth of the VRM. As the switching frequency increases the VRM is faced with efficiency and thermal problems. The current buck topologies suffer large drops in efficiency as the frequency increases from high switching losses. Resonant or …
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Performance Improvements of Multi-Channel Interleaving Voltage Regulator Modules with Integrated Coupling Inductors
… The critical inductance is a function of the control bandwidth and the load transient steps. Although multi-channel interleaving reduces the current ripple stress on the output capacitors, it cannot reduce the current ripples in each channel. The large current ripples reduce the efficiency of …
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Hybrid PWM Update Method for Time Delay Compensation in Current Control Loop
… proposed to eliminate the effect of the one-step control time delay Td one without losing the full duty cycle range. Without the Td one to cause linear phase shifts that limit the control bandwidth and affect closed-loop stability, a very high quality digital current control can be achieved, such …
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Design and control methods for high-accuracy variable reluctance actuators
This thesis presents the design and control techniques of a variable reluctance actuator for driving a reticle motion stage in photolithography scanners. The primary thesis contributions include the design and experimental demonstration of a magnetic flux controller that uses a sense coil …
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Control and Modeling of High-Frequency Voltage Regulator Modules for Microprocessor Application
… regulator module (VRM) challenges of high bandwidth control with fast transient response, high current output, simple implementation, and efficient 48V solution are tackled in this dissertation. With the push for control bandwidth to meet design specifications for microprocessor VRM with …
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A Power Conditioning System for Superconductive Magnetic Energy Storage based on Multi-Level Voltage Source Converter
… contents from the output current. A closed-loop control system is also implemented for the VSC, and shows 600-Hz control bandwidth. The multi-level structure used requires too many high-speed switches. However, not all of them are used at the same time during normal multi-level operation. A new …
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