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.
Results
Showing 1 to 20 of 43 for “"Unity power factor"”.
-
A new unity power factor quasi-resonant induction heater
… heating systems based upon resonant switch mode power converter techniques. The proposed three phase unity power factor induction heating system consists of two stages of power conversions. The important requirements for each stage of the power conversion of a typical induction heating system …
-
A digital controller for a unity power factor converter
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1993.
-
A single three phase variable speed drive with unity power factor
… from the supply are also the result of poor power factors. The converter should therefore operate at close to unit power factor. N Mohan, T Underland, W.P Robins [3].
-
A fast analog controller for a unity power factor AC/DC converter
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1993.
-
Neural network applications in the control of power electronic converters
… widely used PI regulator for the regulation of Power Electronic converters. Neural Networks may be used to both control of and identification in a system. In general, one assumes that the mapping performed by the Neural Network can adequately represent the system's behavior over the desired …
-
Advanced Single-Stage Power Factor Correction Techniques
Five new single-stage power factor correction (PFC) techniques are developed for single-phase applications. These converters are: Integrated single-stage PFC converters, voltage source charge pump power factor correction (VS-CPPFC) converters, current source CPPFC converters, combined voltage …
-
Design and analysis of an active power factor correction circuit
The design of an active-unity power factor correction circuit with variable-hysteresis control for off-line dc-to-dc switching power supplies is described. Design equations relating the boost inductor current ripple to the circuit components selection and circuit performance arc discussed. A …
-
SiC-Based High-Frequency Soft-Switching Three-Phase Rectifiers/Inverters
… to the current industry practice, with a power rating between 10 and 30 kW, the power density are limited by silicon (Si) power semiconductor devices, which make the systems operate at only up to around 30 kHz. The emerging wide bandgap (WBG) power semiconductor devices are considered as …
-
Novel Voltage Control Methods for quasi-Z-source Network Converters with Focus on Fixed DC-Link Voltage, Constant- Frequency and Soft-Switching Operation
Power electronic converters reinforce modern energy systems by enabling efficient power transfer among batteries, renewable sources, and the utility grid. quasi-Z-source (qZS) converters are especially attractive for their single-stage buck–boost capability, continuous input current, and inherent …
-
Modelling and real-time simulation of a modular bidirectional solid-state transformer for ultra-fast charging of electric vehicles
… a three-phase MV utility network enabling high-power and ultra-fast charging capabilities for electric vehicles, with the capacity to incorporate energy storage systems at the MVDC-link. This topological configuration allows bi-directional power flow for Vehicle-to-Grid and for scalability to …
-
Controlling the Vienna rectifier using a simplified space vector pulse width modulation technique
… that the simplified SVPWM provides a low THD, unity Power-Factor (PF) and effective capacitor voltage balancing even after extreme faults. This study introduces a multilevel Power-Factor-Correction (PFC) converter in a 2-stage configuration. The first stage is the Vienna rectifier which has a …
-
A Novel Arc Welding Power Supply with Improved Power Factor Correction
… design and development of a novel Arc Welding Power Supply utilizing a modified two-switch forward converter topology. The proposed design improves the power quality by improving power factor to near unity and reducing total harmonic distortion. State space analysis of the proposed circuit …
-
Development of a converter for grid-tied and isolated operation of an interior permanent magnet synchronous generator, coupled to a twin-shaft gas turbine
South Africa’s overreliance on coal fired power generation has led to the government’s commitment to diversifying the country’s energy mix. Gas turbine generators are poised to play a larger role in South Africa’s energy mix, due to the country’s abundance in natural gas reserves. Therefore, there …
-
Generalized theory of static power frequency changers
… an intermediate dc link) converting polyphase ac power of a given frequency to single or polyphase power of a chosen frequency. The thesis consists of two parts. The first part, comprising five chapters, is devoted to the study of ideal frequency changers operated from ac Sources having zero …
-
Applying the Herman-Beta probabilistic method to MV feeders
… not straight forward as the operation of modern power systems is highly influenced by a variety of uncertain and random variables such as stochasticity in load demand and power generation from renewable energy resources. Classic deterministic methods which model load demand and generation with …
-
Design and Evaluation of a Photovoltaic Inverter with Grid-Tracking and Grid-Forming Controls
… the stabilization of the grid frequency during power system dynamics. The purpose of this thesis is primarily to present the design of a grid-forming control scheme based on the VSM and the derivation of the terminal dq-frame ac impedance of the small-signal model of the inverter and control …
-
Design and Control of a Compact 7.2 kW GaN-Based Bidirectional Isolated On-Board Charger (OBC)
… vehicles, addressing critical challenges in power factor correction, efficiency, and power density. The research introduces innovative control strategies and hardware designs by incorporating high power GaN switches that substantially improve OBC performance and compactness. The thesis …
-
Viability study to implement peak load shaving at UCT Medical School
… a good quality control of the real and reactive power. Secondly a PLS algorithm (PLSA) was developed, which had the aim of setting a threshold point (TP) to prevent the MMD supplied to UCTMS to surpass the TP. In addition, the PLSA in conjunction with designed controllers would charge the battery …
-
Modeling and Characterization of Power Electronic Converters with an Integrated Transmission-Line Filter
… properties. A system model of a power factor correction (PFC) boost converter was completed by using active device models for diodes, MOSFETs, and the gate driver. In addition, equivalent circuits were used to characterize high frequency impedances of the passive components. A PFC …
Page 1 of 3