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- Electrical and Computer Engineering Faculty Research & Creative Works (41)
- Bradley Minch (2)
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- Guru Subramanyam (2)
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Articles 1 - 30 of 60
Full-Text Articles in Engineering
A Novel Physics-Assisted Genetic Algorithm For Decoupling Capacitor Optimization, Li Jiang, Ling Zhang, Shurun Tan, Da Li, Chulsoon Hwang, Jun Fan, Er Ping Li
A Novel Physics-Assisted Genetic Algorithm For Decoupling Capacitor Optimization, Li Jiang, Ling Zhang, Shurun Tan, Da Li, Chulsoon Hwang, Jun Fan, Er Ping Li
Electrical and Computer Engineering Faculty Research & Creative Works
This article proposes a new physics-assisted genetic algorithm (PAGA) for decoupling capacitor (decap) optimization in power distribution networks (PDNs), which is a highly efficient approach to minimizing the number of decaps within an enormous search space. In the proposed PAGA method, the priority of the decap ports is first determined based on their physical loop inductances. Then, an initial solution is quickly obtained by placing decaps sequentially on the port with the highest priority. Subsequently, a GA with prior physical knowledge is developed to find better decap solutions progressively. A port removal scheme that eliminates the low-priority ports and a …
Highly Power Dense Dc To Three-Phase Ac Modular Converters With Tiny Module Capacitors, Wiwin Hartini Lew
Highly Power Dense Dc To Three-Phase Ac Modular Converters With Tiny Module Capacitors, Wiwin Hartini Lew
Dissertations and Theses
A Modular Multilevel Converter (MMC) is an attractive candidate in high power conversion due to its modularity and scalability. The energy storage element, namely the module capacitance in the MMC submodule circuit, is typically large and when scaled to convert high power, requires very bulky module capacitors. In addition to deteriorating the power density, the design necessitates the use of electrolytic capacitors, which further affects the overall converter efficiency and reliability. This research presents an MMC submodule topology and the accompanying modulation approach that reduces the submodule capacitance requirements significantly compared to conventional MMC topology (few micro-farads versus several milli-farads). …
Analysis And Investigation Of Hybrid Dc–Dc Non-Isolated And Non-Inverting Nx Interleaved Multilevel Boost Converter (Nx-Imbc) For High Voltage Step-Up Applications: Hardware Implementation, Mahajan Sagar Bhaskar, Dhafer J. Almakhles, Sanjeevikumar Padmanaban, Frede Blaabjerg, Umashankar Subramaniam, Dan M. Ionel
Analysis And Investigation Of Hybrid Dc–Dc Non-Isolated And Non-Inverting Nx Interleaved Multilevel Boost Converter (Nx-Imbc) For High Voltage Step-Up Applications: Hardware Implementation, Mahajan Sagar Bhaskar, Dhafer J. Almakhles, Sanjeevikumar Padmanaban, Frede Blaabjerg, Umashankar Subramaniam, Dan M. Ionel
Power and Energy Institute of Kentucky Faculty Publications
In significant cases, the generated voltage needs to be step-up with high conversion ratio by using the DC-DC converter as per the requirement of the load. The drawbacks of traditional boost converter are it required high rating semiconductor devices and have high input current ripple, low efficiency, and reverse recovery voltage of the diodes. Recently, the family of Multilevel Boost Converter suggested and suitable configuration to overcome the above drawbacks. In this article, hybrid DC-DC non-isolated and non-inverting Nx Interleaved Multilevel Boost Converter (Nx-IMBC) is analyzed in Continuous Conduction Mode (CCM) and Discontinuous Conduction Mode (DCM) with boundary condition and …
Simulation And Analysis Of Switched Reluctance Generator For Renewable Energy Applications, Simone Sartori, Malabika Basu, Michael Farrell, Andrea Tortella
Simulation And Analysis Of Switched Reluctance Generator For Renewable Energy Applications, Simone Sartori, Malabika Basu, Michael Farrell, Andrea Tortella
Conference papers
The purpose of the paper is to investigate the application of a Switched Reluctance Generator (SRG) for future wave energy converters. This machine presents some favourable features as compared to others. The machine optimal operation can be obtained after a detailed assessment of the control strategy. For this purpose, a SRG model is implemented in Matlab® Simulink® environment to find out the values of the switching angles which maximize the converted power and to set up an appropriate control of the power exchange with the grid to which the machine is connected. The simulation results provide evidence that a proper …
Characterizing Package/Pcb Pdn Interactions From A Full-Wave Finite-Difference Formulation, Shishuang Sun, David Pommerenke, James L. Drewniak, Kai Xiao, Sin-Ting Chen, Tzong-Lin Wu
Characterizing Package/Pcb Pdn Interactions From A Full-Wave Finite-Difference Formulation, Shishuang Sun, David Pommerenke, James L. Drewniak, Kai Xiao, Sin-Ting Chen, Tzong-Lin Wu
James K. Wu, M.D.
A novel approach of equivalent circuit model extraction is developed for modeling of integrated package and PCB power distribution networks (PDN). The integrated PDNs are formulated from a full-wave finite-difference algorithm, and the resulting matrix equations are converted to equivalent circuits. The equivalent circuits, as well as the decoupling capacitors and the attached circuit components, can be analyzed with a SPICE-like solver in both the time and frequency domains. The modeling of dielectric loss is also addressed. The method is used to model three PDN problems including a simple power bus, a BGA package mounting on a PCB, and a …
Challenges And Opportunities For Multi-Functional Oxide Thin Films For Voltage Tunable Radio-Frequency/Microwave Components, Guru Subramanyam, M W. Cole, Nian X. Sun, Thottam S. Kalkur, Nick M. Sbrockey, Gary S. Tompa, Xiaomei Guo, Chonglin Chen, S P. Alpay, G A. Rossetti Jr., Kaushik Dayal, Long-Qing Chen, Darrell G. Schlom
Challenges And Opportunities For Multi-Functional Oxide Thin Films For Voltage Tunable Radio-Frequency/Microwave Components, Guru Subramanyam, M W. Cole, Nian X. Sun, Thottam S. Kalkur, Nick M. Sbrockey, Gary S. Tompa, Xiaomei Guo, Chonglin Chen, S P. Alpay, G A. Rossetti Jr., Kaushik Dayal, Long-Qing Chen, Darrell G. Schlom
Guru Subramanyam
There has been significant progress on the fundamental science and technological applications of complex oxides and multiferroics. Among complex oxide thin films, barium strontium titanate (BST) has become the material of choice for room-temperature-based voltage-tunable dielectric thin films, due to its large dielectric tunability and low microwave loss at room temperature. BST thin film varactor technology based reconfigurable radio frequency (RF)/microwave components have been demonstrated with the potential to lower the size, weight, and power needs of a future generation of communication and radar systems. Low-power multiferroic devices have also been recently demonstrated. Strong magneto-electric coupling has also been demonstrated …
Challenges And Opportunities For Multi-Functional Oxide Thin Films For Voltage Tunable Radio Frequency/Microwave Components, Guru Subramanyam, Melanie W. Cole, Nian X. Sun, Thottam S. Kalkur, Nick M. Sbrockey, Gary S. Tompa, Xiaomei Guo, Chonglin Chen, S. P. Alpay, G. A. Rossetti, Kaushik Dayal, Long-Qing Chen, Darrell Schlom
Challenges And Opportunities For Multi-Functional Oxide Thin Films For Voltage Tunable Radio Frequency/Microwave Components, Guru Subramanyam, Melanie W. Cole, Nian X. Sun, Thottam S. Kalkur, Nick M. Sbrockey, Gary S. Tompa, Xiaomei Guo, Chonglin Chen, S. P. Alpay, G. A. Rossetti, Kaushik Dayal, Long-Qing Chen, Darrell Schlom
Guru Subramanyam
There has been significant progress on the fundamental science and technological applications of complex oxides and multiferroics. Among complex oxide thin films, barium strontium titanate (BST) has become the material of choice for room-temperature-based voltage-tunable dielectric thin films, due to its large dielectric tunability and low microwave loss at room temperature. BST thin film varactor technology based reconfigurable radio frequency (RF)/microwave components have been demonstrated with the potential to lower the size, weight, and power needs of a future generation of communication and radar systems. Low-power multiferroic devices have also been recently demonstrated. Strong magneto-electric coupling has also been demonstrated …
Spark Discharge Coupled Laser Multicharged Ion Source, Md. Haider A. Shaim, Hani E. Elsayed-Ali
Spark Discharge Coupled Laser Multicharged Ion Source, Md. Haider A. Shaim, Hani E. Elsayed-Ali
Electrical & Computer Engineering Faculty Publications
A spark discharge is coupled to a laser multicharged ion source to enhance ion generation. The laser plasma triggers a spark discharge with electrodes located in front of the ablated target. For an aluminum target, the spark discharge results in significant enhancement in the generation of multicharged ions along with higher charge states than observed with the laser source alone. When a Nd:YAG laser pulse (wavelength 1064 nm, pulse width 7.4 ns, pulse energy 72 mJ, laser spot area on target 0.0024 cm2) is used, the total multicharged ions detected by a Faraday cup is 1.0 nC with …
Application Of A Superconducting Magnetic Energy Storage Unit For Power Systems Stability Improvement, Embaiya Salih, Stefan Lachowicz, Octavian Bass, Daryoush Habibi
Application Of A Superconducting Magnetic Energy Storage Unit For Power Systems Stability Improvement, Embaiya Salih, Stefan Lachowicz, Octavian Bass, Daryoush Habibi
Research outputs 2014 to 2021
A superconducting Magnetic Energy Storage (SMES) includes a high inductance coil that can act as a constant source of direct current. A SMES unit connected to a power system is able to absorb and store both active and reactive power from this system and to inject these powers into this system when they are needed. The injected power can be controlled by changing both the duty cycle of the dc-dc chopper switches and its operation modes. A SMES is always associated with a power conversion system consisting of two identical converters connected by a de link capacitor. This paper presents …
Challenges And Opportunities For Multi-Functional Oxide Thin Films For Voltage Tunable Radio Frequency/Microwave Components, Guru Subramanyam, Melanie W. Cole, Nian X. Sun, Thottam S. Kalkur, Nick M. Sbrockey, Gary S. Tompa, Xiaomei Guo, Chonglin Chen, S. P. Alpay, G. A. Rossetti, Kaushik Dayal, Long-Qing Chen, Darrell Schlom
Challenges And Opportunities For Multi-Functional Oxide Thin Films For Voltage Tunable Radio Frequency/Microwave Components, Guru Subramanyam, Melanie W. Cole, Nian X. Sun, Thottam S. Kalkur, Nick M. Sbrockey, Gary S. Tompa, Xiaomei Guo, Chonglin Chen, S. P. Alpay, G. A. Rossetti, Kaushik Dayal, Long-Qing Chen, Darrell Schlom
Electrical and Computer Engineering Faculty Publications
There has been significant progress on the fundamental science and technological applications of complex oxides and multiferroics. Among complex oxide thin films, barium strontium titanate (BST) has become the material of choice for room-temperature-based voltage-tunable dielectric thin films, due to its large dielectric tunability and low microwave loss at room temperature. BST thin film varactor technology based reconfigurable radio frequency (RF)/microwave components have been demonstrated with the potential to lower the size, weight, and power needs of a future generation of communication and radar systems. Low-power multiferroic devices have also been recently demonstrated. Strong magneto-electric coupling has also been demonstrated …
Programmable Multiple Input Translinear Elements, Haw-Jing Jo, Guillermo Serrano, Paul Hasler, David Anderson, Bradley Minch
Programmable Multiple Input Translinear Elements, Haw-Jing Jo, Guillermo Serrano, Paul Hasler, David Anderson, Bradley Minch
Bradley Minch
Large networks composed of multiple input translinear elements (MITEs) have been typically limited by the mismatches between individual MITEs. This paper presents the methodology that allows for such systems to be feasible through the application of floating-gate programming techniques. We introduce designs for a programmable MITE, and demonstrate the ability to systematically reduce offsets through accurate programming of example circuits.
A Transistor-Only Circuit Model Of The Autozeroing Floating-Gate Amplifier, Paul Hasler, Matt Kucic, Bradley Minch
A Transistor-Only Circuit Model Of The Autozeroing Floating-Gate Amplifier, Paul Hasler, Matt Kucic, Bradley Minch
Bradley Minch
We developed an transistor-only version of our autozeroing floating-gate amplifier (AFGA). We use a subthreshold transistor to model the behavior of an electron-tunneling device, and we use another subthreshold transistor to model the behavior of pFET hot-electron injection. We have derived analytical models that completely characterize the amplifier and that are in good agreement with experimental data. This circuit is a bandpass filter, and behaves similarly to the AFGA with different operating parameters. Both the low-frequency and high-frequency cutoffs are controlled electronically, as is done in continuous-time filters. This circuit has a low-frequency cutoff at frequencies above 1 Hz, and …
Modeling Polarization And Capacitance Hysteresis Of Ferroelectric Capacitors, Bikash Shrestha
Modeling Polarization And Capacitance Hysteresis Of Ferroelectric Capacitors, Bikash Shrestha
Electrical Engineering Theses
A simulation based comparative study of the polarization hysteresis of the ferroelectric capacitor using various ferroelectric models is presented. A 2-dimensional finite element device-level model was implemented using SILVACO's ATLAS device simulator to generate the polarization hysteresis characteristics for Au/Poly(vinylidene fluoride-trifluoroethylene)/Au metal-insulator-metal (MIM) device. Landau free energy expression for electric field in terms of polarization is also implemented in MATLAB to produce the polarization hysteresis curves of monocrystalline and polycrystalline ferroelectrics. The main drawback of previous models was their inability to predict polarization saturation at the same electric field limits as compared with measurements taken from a recently fabricated ferroelectric …
Dynamic Response Improvement In A Buck Type Converter Using Capacitor Current Feed-Forward Control, Lisheng Shi, Mehdi Ferdowsi, Mariesa Crow
Dynamic Response Improvement In A Buck Type Converter Using Capacitor Current Feed-Forward Control, Lisheng Shi, Mehdi Ferdowsi, Mariesa Crow
Electrical and Computer Engineering Faculty Research & Creative Works
The dynamic performance of dc-dc power electronic converters is mainly determined by the output filtering capacitor and inductor, control loop(s) compensator(s), and the voltage conversion ratio. Normally, a larger capacitance and/or a smaller inductance are not recommended because of the extra cost and size of the capacitor and/or the increment of the inductor current ripple. The capacitor current feed-forward method has gained popularity due its fast dynamic response, simpler structure, and less sensing losses. In applications where a large voltage conversion ratio is needed, dynamic response for a load step-down scenario is worse than that of a load step-up condition. …
A System Design Approach For Unattended Solar Energy Harvesting Supply, Jonathan W. Kimball, Brian T. Kuhn, Robert S. Balog
A System Design Approach For Unattended Solar Energy Harvesting Supply, Jonathan W. Kimball, Brian T. Kuhn, Robert S. Balog
Electrical and Computer Engineering Faculty Research & Creative Works
Remote devices, such as sensors and communications devices, require continuously available power. In many applications, conventional approaches are too expensive, too large, or unreliable. For short-term needs, primary batteries may be used. However, they do not scale up well for long-term installations. Instead, energy harvesting methods must be used. Here, a system design approach is introduced that results in a highly reliable, highly available energy harvesting device for remote applications. First, a simulation method that uses climate data and target availability produces Pareto curves for energy storage and generation. This step determines the energy storage requirement in watt-hours and the …
A Mems Multi-Cantilever Variable Capacitor On Metamaterial, Luke A. Rederus
A Mems Multi-Cantilever Variable Capacitor On Metamaterial, Luke A. Rederus
Theses and Dissertations
Negative refractive index materials are an example of metamaterials that are becoming increasingly popular. Research into these metamaterials could possibly be the first steps toward bending electromagnetic radiation (i.e., microwaves, light, etc.) around an object or person. Split ring resonators (SRR) are classified as metamaterials that create an artificial magnetic response from materials with no inherent magnetic properties. Once fabricated, an SRR has a specific resonant frequency due to its permanent geometry. This research introduces a new concept of using a variable capacitive micro- electro-mechanical system (MEMS) device located at the gap of an SRR to mechanically alter the capacitance …
Prediction Of Effective Permittivity Of Diphasic Dielectrics Using An Equivalent Capacitance Model, Sandeep K. Patil, Marina Koledintseva, Robert W. Schwartz, Wayne Huebner
Prediction Of Effective Permittivity Of Diphasic Dielectrics Using An Equivalent Capacitance Model, Sandeep K. Patil, Marina Koledintseva, Robert W. Schwartz, Wayne Huebner
Electrical and Computer Engineering Faculty Research & Creative Works
An analytical model based on an equivalent capacitance circuit for expressing a static effective permittivity of a composite dielectric with complex-shaped inclusions is presented. The dielectric constant of 0-3 composites is investigated using this model. The geometry of the capacitor containing a composite dielectric is discretized into partial parallel-plate capacitor elements, and the effective permittivity of the composite is obtained from the equivalent capacitance of the structure. First, an individual cell diphasic dielectric (a high-permittivity spherical inclusion enclosed in a lower permittivity parallelepiped) is considered. The capacitance of this cell is modeled as a function of an inclusion radius/volume fraction. …
Parametric Study Of Alternative Ev1 Powertrains, Adam Saplin, Andrew Meintz, Mehdi Ferdowsi
Parametric Study Of Alternative Ev1 Powertrains, Adam Saplin, Andrew Meintz, Mehdi Ferdowsi
Electrical and Computer Engineering Faculty Research & Creative Works
The General Motors (GM) EV1 is an electric vehicle originally powered by either a PbA or NiMh battery pack. This paper examines the possibility of alternative powertrain configurations. These alternatives include an ultracapacitor (UC) storage system, fuel cell system with UC storage, and a fuel cell system with a NiMh battery pack. The configurations were simulated using ADVISOR. Parametric tests were performed by varying the size of the energy storage systems. The study of these combinations is followed by an examination of the current art of the hybrid energy storage topologies used to combine battery and ultracapacitor storage. These topologies …
An Improved Cascaded H-Bridge Multilevel Inverter Controlled By An Unbalanced Voltage Level Sigma-Delta Modulator, Jingsheng Liao, Mehdi Ferdowsi
An Improved Cascaded H-Bridge Multilevel Inverter Controlled By An Unbalanced Voltage Level Sigma-Delta Modulator, Jingsheng Liao, Mehdi Ferdowsi
Electrical and Computer Engineering Faculty Research & Creative Works
Multilevel inverters have been proven to be viable solutions for high-power automotive motor drive applications due to their high volt-ampere ratings. Cascaded H-bridge inverters are a promising breed of multilevel inverters which generally require several independent dc sources. Replacement of all but one of the dc sources with capacitors in cascaded H-bridge multilevel inverters, which leads to single-dc-source per-phase cascaded inverters, has recently gained popularity. However, very few efforts have been made to address the challenging problem of voltage regulation in the replacing capacitors. In this paper, applicability of a real-time voltage control technique named unbalanced voltage level sigma-delta modulation …
A Unique Ultracapacitor Direct Integration Scheme In Multilevel Motor Drives For Large Vehicle Propulsion, Shuai Lu, Keith Corzine, Mehdi Ferdowsi
A Unique Ultracapacitor Direct Integration Scheme In Multilevel Motor Drives For Large Vehicle Propulsion, Shuai Lu, Keith Corzine, Mehdi Ferdowsi
Electrical and Computer Engineering Faculty Research & Creative Works
This paper introduces a new set of methods to directly integrate ultracapacitor banks into cascaded multilevel inverters that are used for large vehicle propulsion. The idea is to replace the regular dc-link capacitors with ultracapacitors in order to combine the energy storage unit and motor drive. This approach eliminates the need for an interfacing dc-dc converter and considerably improves the efficiency of regenerative braking energy restoration in large vehicles using multilevel converters. Utilizing the proposed modulation control set, the two cascaded inverters can have their dc voltage levels maintained at any ratio (even a noninteger ratio) or dynamically varied over …
An Unique Ultracapacitor Direct Integration Scheme In Multilevel Motor Drives For Large Vehicle Propulsion, Shuai Lu, Keith Corzine, Mehdi Ferdowsi
An Unique Ultracapacitor Direct Integration Scheme In Multilevel Motor Drives For Large Vehicle Propulsion, Shuai Lu, Keith Corzine, Mehdi Ferdowsi
Electrical and Computer Engineering Faculty Research & Creative Works
This paper introduces a new set of methods to directly integrate ultracapacitor banks into cascaded multilevel inverters used for large vehicle propulsion. The idea is to replace the regular dc-link capacitors with ultracapacitors in order to combine the energy storage unit and motor drive. This approach eliminates the need for an interfacing dc-dc converter and considerably improves the efficiency of regenerative braking energy restoration in electric and hybrid vehicles. Utilizing the proposed modulation control set, the two cascaded inverters can have their dc voltage levels maintained at any ratio (even a noninteger ratio) or dynamically varied over a wide range …
Analysis Of The Double-Tiered Three-Battery Switched Capacitor Battery Balancing System, Andrew Baughman, Mehdi Ferdowsi
Analysis Of The Double-Tiered Three-Battery Switched Capacitor Battery Balancing System, Andrew Baughman, Mehdi Ferdowsi
Electrical and Computer Engineering Faculty Research & Creative Works
The auto industry is progressing towards hybrid and fully electric vehicles in their future car models. These vehicles need a power plant that is reliable during the lifetime of the car. Battery and ultra-capacitor capacity imbalances stemming from manufacturing and ensuing driving environment and operational usage affect voltage levels, which must adhere to strict limits to ensure the safety of the driver. A double-tiered capacitive shuttling technique is applied to an idealized three-battery system simulation in order to balance the voltages. Parameters in the system are varied and their effects on the system determined. Results are compared to a single-tiered …
Characterizing Package/Pcb Pdn Interactions From A Full-Wave Finite-Difference Formulation, Shishuang Sun, David Pommerenke, James L. Drewniak, Kai Xiao, Sin-Ting Chen, Tzong-Lin Wu
Characterizing Package/Pcb Pdn Interactions From A Full-Wave Finite-Difference Formulation, Shishuang Sun, David Pommerenke, James L. Drewniak, Kai Xiao, Sin-Ting Chen, Tzong-Lin Wu
Electrical and Computer Engineering Faculty Research & Creative Works
A novel approach of equivalent circuit model extraction is developed for modeling of integrated package and PCB power distribution networks (PDN). The integrated PDNs are formulated from a full-wave finite-difference algorithm, and the resulting matrix equations are converted to equivalent circuits. The equivalent circuits, as well as the decoupling capacitors and the attached circuit components, can be analyzed with a SPICE-like solver in both the time and frequency domains. The modeling of dielectric loss is also addressed. The method is used to model three PDN problems including a simple power bus, a BGA package mounting on a PCB, and a …
Non-Unity Active Pfc Methods For Filter Size Optimization, Yongxiang Chen, Jonathan W. Kimball, Philip T. Krein
Non-Unity Active Pfc Methods For Filter Size Optimization, Yongxiang Chen, Jonathan W. Kimball, Philip T. Krein
Electrical and Computer Engineering Faculty Research & Creative Works
Active power factor correction seeks to obtain unity power factor and sinusoidal line currents. Optimized nonsinusoidal line currents reduce filter capacitor requirements with a nonunity target power factor. Implementation methods are presented that permit reduced power factor to be traded off against filter size in a nearly optimum manner. A simple waveform shape can reduce filter component size by about 40% in active PFC converters at the same level of complexity as in conventional PFC designs while yielding power factor as high as 0.9. Two approximate methods to generate appropriate shapes are presented. They offer direct practical implementation of nonunity …
Modeling Of Capacitor Impedance In Switching Converters, Jonathan W. Kimball, Philip T. Krein, Kevin R. Cahill
Modeling Of Capacitor Impedance In Switching Converters, Jonathan W. Kimball, Philip T. Krein, Kevin R. Cahill
Electrical and Computer Engineering Faculty Research & Creative Works
Switched capacitor (SC) converters are gaining acceptance as alternatives to traditional, inductor-based switching power converters. Proper design of SC converters requires an understanding of all loss sources and their impacts on circuit operation. In the present work, an equivalent resistance method is developed for analysis, and equivalent resistance formulae are presented for various modes of operation. Quasiresonant converters are explored and compared to standard SC converters. Comparisons to inductor-based switching power converters are made. A number of capacitor technologies are evaluated and compared for applications to both SC converters and inductor-based converters. The resulting model can be used to accurately …
Analysis And Design Of Switched Capacitor Converters, Jonathan W. Kimball, Philip T. Krein
Analysis And Design Of Switched Capacitor Converters, Jonathan W. Kimball, Philip T. Krein
Electrical and Computer Engineering Faculty Research & Creative Works
Switched capacitor converters have become more common in recent years. Crucial to understanding the maximum power throughput and efficiency is a model of the converter's equivalent resistance. A new form for equivalent resistance is derived and discussed in a design context. Quasi-resonant operation is also explored and compared to non-resonant operation. Several capacitor technologies are evaluated and compared.
Double-Tiered Capacitive Shuttling Method For Balancing Series-Connected Batteries, Andrew Baughman, Mehdi Ferdowsi
Double-Tiered Capacitive Shuttling Method For Balancing Series-Connected Batteries, Andrew Baughman, Mehdi Ferdowsi
Electrical and Computer Engineering Faculty Research & Creative Works
The auto industry is progressing towards hybrid and fully electric vehicles in their future car models. These vehicles need a power plant that is reliable during the lifetime of the car. Battery capacity imbalances stemming from the cell manufacturer, ensuing driving environment, and operational usage affect voltage levels, which must follow adherence to strict limits to ensure the safety of the driver. A variation on an existing method of using a capacitor to shuttle charge from one battery to another to balance series strings of batteries is proposed in this paper. The advancement shown in this paper is to bridge …
Analysis Of A Low-Pass Filter Employing A 4-Pin Capacitor, A. Ritter, Todd H. Hubing, Thomas Van Doren, Theodore M. Zeeff
Analysis Of A Low-Pass Filter Employing A 4-Pin Capacitor, A. Ritter, Todd H. Hubing, Thomas Van Doren, Theodore M. Zeeff
Electrical and Computer Engineering Faculty Research & Creative Works
Capacitors with two or three leads tend to make poor low-pass filters at high frequencies (e.g. greater than 100 MHz) due to the mutual inductance between the input and output sides of the filter. This work proposes a four-lead low-pass filter capacitor design that minimizes the magnetic flux coupling between the input and output. Measurements of a prototype capacitor confirm that it performs significantly better than a typical two-lead capacitor at high frequencies.
Low-Input-Voltage, Low-Power Boost Converter Design Issues, Jonathan W. Kimball, Theresa L. Flowers, Patrick L. Chapman
Low-Input-Voltage, Low-Power Boost Converter Design Issues, Jonathan W. Kimball, Theresa L. Flowers, Patrick L. Chapman
Electrical and Computer Engineering Faculty Research & Creative Works
Issues associated with boost converter design and performance are investigated when a low input voltage is used. Low-input-voltage sources include single fuel cells, single solar cells, and thermoelectric devices. The primary context is interfacing single micro fuel cells to portable electronic loads, such as mobile phones. Efficiency and circuit startup are the two most difficult issues for a low-cost design. It is shown in theory and experiment that the boost converter has a voltage collapse point. A simple startup technique is proposed that is appropriate for some applications.
Series-Parallel Approaches And Clamp Methods For Extreme Dynamic Response With Advanced Digital Loads, Philip T. Krein, Jonathan W. Kimball
Series-Parallel Approaches And Clamp Methods For Extreme Dynamic Response With Advanced Digital Loads, Philip T. Krein, Jonathan W. Kimball
Electrical and Computer Engineering Faculty Research & Creative Works
The series-input parallel-output dc-dc converter combination provides inherent sharing among the converters. With conventional controls, however, this sharing is unstable. Recent literature work proposes complicated feedback loops to correct the problem, at the cost of dynamic performance. This paper shows that a simple sensorless current mode control stabilizes sharing with fast dynamics suitable for advanced digital loads. With this control in place, a "super-matched" current sharing control emerges. Sharing occurs through transients, limited only by the energy limits of the converters. The control approach has considerable promise for high-performance voltage regulator modules. For even faster response, clamping techniques are proposed.