Opening Plenary

Monday, February 6, 2012

Time: 1:30 pm – 2:00 pm

Speaker: Dr. Fred Lee

University Distinguished Professor

Virginia Tech

"Current Mode Control and Modeling- 3 Decades of Progress"

The paper starts with a review of the history of development of current mode control and various modeling attempts. The topic of modeling for current mode control, although seemingly settled, still left many unsolved issues. Arthur Brown proposed the discrete time domain sample-data modeling, in the 80’s, which accurately predicted the sub-harmonic oscillation associated with the peak current model control. Subsequently, Brown’s discrete time domain model was reformulated and simplified by Ray Ridley in frequency domain to offer it as a design-oriented modeling and analysis tool. The discrete time sample-data modeling was essentially based on constant frequency operation. It has limited applications to other forms of current-mode control, such as variable frequency control and average current-mode control.

In light of recent surge of interest in constant on-time variable frequency control for improved light load efficiency and V2 control for its fast transients and simplicity, the existing modeling tools were not quite suitable for these popular controls. The desire for more unified approach of modeling has motivated Jian Li to attack this difficult modeling task with an entirely different approach, i.e. from a continuous time framework using the extended describing function techniques. The developed modeling is accurate beyond switching frequency and is applicable to constant frequency peak current/valley mode control, average current mode, charge control as well as variable frequency constant Ton and Constant Toff control. Furthermore a reduced-order model was presented with accuracy up to the switching frequency. The model was further simplified by Ying Yi Yang into a unified equivalent circuit model, namely, “three-terminal current-mode control cell” which accurately characterizes the terminal properties of the three-terminal switch cell embodied the current feedback loop. This three-terminal cell can be applied to a large class of converter topologies employing a current mode control of one form or another, much the same way as the “three-terminal switch cell” average model developed by Vorperian that characterizes the nonlinearity of the active-switch and diode pair in a converter. This modeling approach has been further extended to V2 control employing various forms of modulation techniques with pin-point accuracy beyond switching frequency.

Time: 2:00 pm – 2:30 pm

Speaker:  Tom Buzak

President

Tektronix Component Solutions

"Challenges and Opportunities of Power Engineering Instrumentations”

The current global focus on energy-related applications has sparked a new wave of creativity and innovation in the design of power devices, modules, and systems. New semiconductor materials such as SiC and GaN, and new battery technologies are beginning to be deployed. Improved topologies for converter and inverter designs are being evaluated to improve conversion efficiency. Wind and PV systems continue to mature and hybrid and electric vehicles are no longer just a curiosity. These development activities have driven changes in the tools needed to validate designs and verify performance. The adoption of higher voltages, currents, and switching frequencies coupled with increasing certification requirements, has resulted in engineers facing unexpected design, verification, and test challenges. In this talk, we will review response to these challenges which has been parallel innovation in measurement and characterization tools and approaches.

Time: 2:30 pm – 3:00 pm

Speaker: John Oenick

Director of Power Electronics

Phoenix International

"The Challenges of Developing Electric Traction Drives for Heavy Duty Work Vehicles"

The presentation will begin with a brief company profile on Phoenix International – a John Deere company specializing in vehicle electronics. This will explain how Phoenix International fits into the John Deere Enterprise, the current product portfolio and the firm’s core competencies in vehicle electronics for Heavy Duty Work Vehicles. This section will include a brief profile of the client base, the types of Work Vehicles they produce and the significant benefit of hybrid drivelines to HD Work Vehicles. The introduction will end with the rational for expanding the Phoenix International product line into High Voltage Vehicle Traction Drives to Support the Industries adoption of Hybrid Drive Systems and some of the alternative providers for vehicle electric drives.

The next section will highlight the electric drive applications and vehicle forms our clients have brought to production or publically disclosed as advanced concept prototype systems / vehicles. This section will review both Class A (12-60 VDC) auxiliary motor drive applications and Class B (61-2400 VDC) vehicle traction drives. The presentation will explore the vehicle architecture of some key examples to highlight commonality, benefits and specific challenges across a variety of vehicle architectures and electric drive applications:

• Commercial Turf and Utility Equipment for Golf Course Maintenance
• Series Electric Front End Loaders from John Deere and LeTourneau. 
• Battery Electric Specialty Automotive solutions from Aptera and Amp
• Utility Vehicle traction and auxiliary solutions from Dueco and Odyne

The key theme will be the efforts of vehicle manufacturers to identify early applications for electric drives that provide multiple benefits to aid market adoption. Market adoption on lead vehicle forms will enable higher volume production techniques and continued development of well integrated electric drive solutions that compete on cost with conventional drivelines on a broader range of vehicles.

With the appropriate background set, the presentation will then focus on the on the specific technical challenges of developing Power Electronics for Heavy Duty work vehicle applications. The process of power module selection based on the intended vehicle drive load profile, continuous and peak current requirements and vehicle manufacturers Power Electronics cooling media and system configurations. Life requirements and methods for demonstrating required durability via advance product verification and validation methods. Extreme vehicle ambients, performance requirements and durability effects with detail on the special methods developed to mitigate the detrimental effects of operation under extreme conditions. Special considerations for existing and future standards compliance requirements and power inverter design considerations. Fault detection monitoring best practices and capabilities.

I will close with the many benefits of electric drive application to vehicles for traction and auxiliaries. The potential to provide a win – win solution for vehicle drives that takes advantage of the inherent low speed torque advantages of electric machines over ICEs (Internal Combustion Engines) to improve vehicle performance and productivity while reducing fuel consumption, emissions and overall environmental impact. I have the utmost respect for the engineers and scientist working in Power and the renascence you are enabling in vehicle hybridization, renewable energy and smart grid implementation. For HD work vehicle hybridization, the key is for the industry to choose initial applications wisely to provide multiple advantages to overcome price premiums and enable larger scale adoption and reduce cost. I will close with why it is a great time for be a Power Electronics engineer and how proud the attendees should feel to be key participants and enablers of the vehicle hybridization revolution.

Time: 3:30 pm – 4:00 pm

Speaker:  Dan Kinzer

Chief Technology Officer and Senior Vice President

Fairchild Semiconductor

"Maximizing Fossil Fuel Saving Through Power Electronics"

Power electronics technologies are fundamental to reducing energy consumption in many applications, and to developing cost effective energy alternatives to fossil fuels. The total fuel savings opportunities will be analyzed in applications like HVAC, industrial drives, lighting, automotive, appliances, power grid, energy storage, internet, communications, computing, and entertainment. New power electronic technologies will be compared for their impact. Examples will be drawn from wide band gap and silicon power device performance improvement, module and component level packaging, power distribution architecture, and advanced power control techniques.

Time: 4:00 pm – 4:30 pm

Speaker: Dr. Babak Fahimi

Professor of Electrical Engineering

University of Texas - Dallas

"Fault Tolerant and Efficient Electric Drive Technologies for E-Mobility"

Power electronic driven adjustable speed motor drives play a central role in electrification of the transportation industry. It is in this context that development of fault resilient, highly efficient, compact, and cost effective electric traction systems can catalyze a seamless transition to e-mobility. To address these challenges innovative magnetic design, power electronic design, sensors and control mechanisms, and novel integrations methods are required. An evaluation of the-state-of-the-art indicates that research and development in all of the above categories are far from exhausted. Furthermore, given the size of the automotive market, issues such as supply chain of components, quality control, manufacturing, and the use of cyber systems ought to be taken into account for future. This talk will provide the audience with the opportunities and challenges related to the electric traction, its current status, and future priorities.  

Time:  4:30 pm – 5:00 pm

Speaker: Dr. Vlatko Vlatkovic

GM of Engineering and Technology

GE Converteam

"Power Electronics for Energy and High Power"

Power electronics is rapidly displacing mechanical means of propulsion and motion control, and is moving upstream in the process of electricity use, distribution and generation. The talk will focus on trends in high power applications and use of power electronics in electricity generation and distribution. We will examine examples of advanced power electronics applications in oil and gas industry in renewable power generation and in electricity transmission and distribution.