Research Activities in Power Electronics at UCF Florida Power Electronics Center Orlando, Florida USA [email protected] Presentation at Princess Sumaya.

Research Activities in Power Electronics at UCF Florida Power Electronics Center Orlando, Florida USA [email protected] Presentation at Princess Sumaya University for Technology

Outline of topics About Florida Power Electronics Center Single-Stage PFC Converters Low Voltage DC-DC converters Inverters Generalized Analysis of DC-DC Converters

WELCOME TO FLORIDA Orlando Area

Florida Power Electronics Center Power Factor Correction (PFC) Circuits - NASA Soft-Switching DC-DC Converters - I-4 Florida Initiative Low voltage AC-DC and DC-DC Converters - NSF Dynamic Modeling and Control - NSF Electromagnetic Interference and Compatibility - NSF Inverter Application / Photovoltaic Cell Industry & I-4 Dr.Issa Batarseh Director Dr.Wenkai Wu Asst Director High Frequency AC DPS NSF & I-4 Smart Electronic Load Maximum Power Point Tracking System

Topologies and Converter System Dr. Issa Batarseh Magnetics Dr. Thomas Wu Power Devices Dr.J J Liou Modeling and Control Dr.Zhihua Qu Packaging Dr.Louis Chow Multidisciplinary Research Group

FloridaPEC - Team Christopher Iannello Jaber A.Abu Qahouq Wei Gu Wenkai Wu Wei Hong Khalid Rustom Joy Mazumdar Shailesh Anthony Duy Bui Abdelhalim M Alsharqawi Shiguo Luo Jia Luo Songqrian Deng Peter Kornetzky Jay Vaidya Shilba Reedy FloridaPEC.engr.ucf.edu

AC/DC converter power supply Telecommunication device, and other industrial equipment Computer TV sets Medical equipment ~ Converter AC SourceDC Load Power Conversion

Single-Stage PFC Converters

For linear load: For nonlinear load : Definition of Power Factor

--Distortion factor, where --Displacement factor Special Case

Typical Line Current Waveform Without PFC Line current is zero when v l (t) < v c (t). PF 0.67 THD >110%

PFC Approaches i) Passive PFC converter ii) Active two-stage PFC converter iii) Active single-stage PFC converter

Three Basic PFC Approaches Active two stage PFC converter Active single stage PFC converter Passive PFC converter

Special Family-- Single-stage PFC AC/DC Converter PFC stage and DC/DC stage share the same switch Single Loop

Prior Art (b) Boost/forward combination DCM+DCM (Russian circuit, 1992) (a) Boost/flyback combination DCM+DCM (Redl, 1994) Advantage Simple Least component count Disadvantage Inherent Low efficiency High DC Bus Voltage Stress Turn off spike Advantage No turn off spike Low voltage rated capacitor Disadvantage Inherent Low efficiency High DC Bus Voltage Stress

Final DC output power 1 2 Final DC output power 1 2 Rough DC power 1 Rough DC power 1 DC/DC cell eff. 2 DC/DC cell eff. 2 Ac input PFC cell eff. 1 Conventional Energy transfer concept

DC output power k 1 2 +(1-k) 1 DC output power k 1 2 +(1-k) 1 DC power k 1 DC/DC cell eff. 2 DC/DC cell eff. 2 Ac input PFC cell eff. 1 Direct transfer power (1-k) 1 Direct transfer power (1-k) 1 k 1-k New energy transfer concept k 1 2 +(1-k) 1 > 1 2

Flyboost PFC cell + Flyback DC/DC cellFlyboost PFC cell + Flyback DC/DC cell Single active switch + single controllerSingle active switch + single controller New Concept

Operation mode Flyback mode:|V in | < V cs n 1 * V oFlyback mode:|V in | < V cs n 1 * V o Boost mode: |V in | > V cs n 1 * V oBoost mode: |V in | > V cs n 1 * V o

Simulation results Trace 1 Current through flyback winding Trace 2 Rectified input current Trace 3 DC/DC stage current Operation waveform in one line cycle

Apply to other topologies

a.Measured Power Factor vs. line voltage b.Measured Efficiency vs. line voltage c.Measured storage capacitor voltage (Vs) vs. line voltage d.Line voltage and line current at line voltage=110V AC. Trace A: Line voltage (100V/div, 5ms/div); Trace B: Line current (measured after auxiliary line filter;1A/div; 5ms/div). The measured Power Factor is 99.4% Experimental Results

Special application Bi-Flyback Converter Inegrate Bifred and Flyboost topologiesInegrate Bifred and Flyboost topologies Two flyback transformers, single switchTwo flyback transformers, single switch Single DC bus capacitorSingle DC bus capacitor

Soft switching application

Developed prototype

Input voltage: 220V Output watts 150W Input voltage: 110V Output watts 150W Line Voltage Line Current Line Voltage Line Current Waveforms

Waveforms for the main switch V ds IdId

Efficiency and Power Factor 200KHz/[email protected]

Improved Results

Key Features Higher efficiency due to soft switching operation of the main switch. Low DC bus voltage make commercially available capacitor can be used as the energy storage part Higher efficiency due to direct energy transfer in Flyback mode Higher power density due to high frequency operation, which also benefit from soft switching

Low-Voltage High-Current Fast-Transient On-Board Voltage Regulator Modules (VRMs) Powering Future Generation of Microprocessors and ICs Low-Voltage High-Current Fast-Transient On-Board Voltage Regulator Modules (VRMs)

Structure

The Main Power Supply Requirements (Challenges) 1. High output current slew rate (> 50A/ s). 2. Low output voltage ripple and overshoot during transient (< 2% of the nominal output voltage). 3. High efficiency 4. High power density. 5. High VRM input current slew rate (

Research Activities in Power Electronics at UCF Florida Power Electronics Center Orlando, Florida USA [email protected] Presentation at Princess Sumaya.

Documents