Dale Dolan

Simulation of a photovoltaic emulator

This paper will outline the simulation of a photovoltaic emulator. A photovoltaic emulator is a DC-DC converter which has similar electrical characteristics to a photovoltaic panel. A photovoltaic emulator allows PV systems to be analyzed in a controlled environment where using actual photovoltaic panels would produce inconsistent results for the PV system, due to variability in outside temperature and weather conditions.

Development of a photovoltaic panel emulator using Labview

With increasing interest in renewable energies, large amounts of money and effort have been put into research and development for photovoltaic systems. The larger interest in PV systems has increased demand for appropriate equipment to test PV systems and for teaching and training the next generation of workers for the sector. A photovoltaic emulator is a device that satisfies a portion of these needs. A photovoltaic (PV) emulator was created using a programmable DC power supply and a developed GUI using Labview. The photovoltaic emulator provides the same current and voltage characteristics as any desired PV panel under various sets of environmental conditions. A PV emulator allows the remaining system to be analyzed in a controlled environment with control over the inherent variability of outside temperature and weather conditions and allows repeatable conditions to test PV equipment such as inverters and MPPT algorithms. The emulator provides an ideal tool and environment for both teaching and research at the University level without the costly investment of a set of commercial PV emulators. An existing power supply that can be used for a variety of other purposes is controlled via Labview to emulate a photovoltaic panel. The power supply can provide an open circuit voltage of 60V and short circuit current of 9A, such that any panel with parameters within this range may be emulated. Thus an extensive variety of panels may be emulated and the majority of panels from the Sandia database are within the capabilities of the available power supply.

Development of wind tunnel for laboratory wind turbine testing

This paper presents the development of a wind tunnel that will be used for wind turbine testing in a controlled environment. The prototype is designed to be able to provide wind speeds of up to 20 m/s (∼43mph) depending on the cross sectional area of the tunnel chamber. A 42 inch tube axial fan is driven by a 5hp induction motor using a variable frequency drive to allow continuously variable wind speeds from near zero up to the maximum wind speed. The fan is rated to produce ∼25,000 CFM and the corresponding wind speed is therefore dependent on chamber cross sectional area. There will be two chamber sizes possible. One is 2.5 feet by 2.5 feet and the other is 3.25 feet by 3.25 feet. The larger cross section allows larger turbines to be tested while the smaller cross section allows higher wind speeds to be reached. The paper also describes some possible applications of the apparatus in the academic environment.

A new multiphase multi-interleaving buck converter with bypass LC

As the number of transistors in microprocessors increases, their power demand increases accordingly. This poses design challenges for their power supply module called VRM (Voltage Regulator Module) especially when operated at sub voltage range. This paper presents the design of a new multiphase multi-interleaving topology that addresses these challenges. A lab scaled hardware prototype of the new topology shows improved load regulation, output voltage ripple and dynamic response time compared to a commercially available power supply module.

Harmonics and Dynamic Response of a Virtual Air Gap Variable Reactor

As more sustainable energy generation is integrated into power grid, the control of power flow in an efficient and effective manner becomes more and more essential. A new innovative device is presented that allows the control of line power flow without the high harmonics and efficiency losses of traditional methods. This paper presents the dynamic response and the harmonics of a laboratory prototype Virtual Air Gap Variable Reactor (VAG-VR) and compares them with those of a thyristor controlled reactor (TCR). Variable Reactors have many applications in the power industry. Their use allows control of line power flow, voltage regulation, as well as damping of power oscillations and sub synchronous resonances. A variable reactor is most commonly implemented as a TCR by switching in and out a constant reactance to achieve an averaged variable reactance. By using a virtual air gap, implementation of a continuously variable reactance is possible with a better dynamic response and without introducing the harmonics created by the thyristor switching of a TCR.

Solar trainer for laboratory photovoltaic systems education

This paper presents the development of a solar trainer to be used as a photovoltaic systems educational instrument in a laboratory environment. It allows various balance of system components to be investigated and the impact of environmental conditions when generating power with solar photovoltaic panels to be studied. The stimuli tested include tilt of the panel, light intensity, and temperature. The trainer also includes the ability to test the effect of different types of solar pv panels, charge controllers, inverters, and battery types. The entire design is contained within a self-powered, easily portable rolling cart.

Design and Simulation of Multiple-Input Single-Output DC-DC Converter

This paper presents the design and simulation of Multiple-Input Single-Output (MISO) dc-dc converter. The main purpose of the converter is to allow connection of multiple power sources to a single dc bus system. Design and modeling of the MISO converter will first be discussed. Results of the computer simulation will be presented which demonstrate the ability of the converter to accept multiple dc sources while outputting only one dc voltage.

Digital Control of Parallel-Connected DC-DC Converters

This paper presents a digitally-controlled paralleled DC-DC converter. The main objective of the digital control is to achieve load sharing while operating at close to peak efficiency over an extremely wide load range. Results from computer simulations using Simulink show the digital control could indeed accomplish the objectives, but the improvements over a single converter depend on the original efficiency characteristics of the converters. An application for a high-power electric vehicle charger utilizing this converter setup is considered.

A low cost portable parabolic solar concentrator for combined heat and power

This paper details the development of a portable parabolic solar concentrator system. The prototype is designed to be able to provide high quality heat or steam using a mobile, self contained system. A UV stable thermoplastic mirror is coupled with a lightweight parabolic frame and a vacuum insulated heat collection pipe. The system features a novel heliostat design, allowing simple collector scalability to virtually any size. A 1.5 square meter mirror was prototyped and tested to compare the designs performance with traditional stationary parabolic solar concentrators. The durability, cost, and set-up procedure for the system is also commented upon. In addition, this paper describes the possible applications of the system including desalination, power generation, and industrial heat supply.

A new multiphase interleaving buck converter with bypass cell capacitor and inductor

As the number of transistors in microprocessors increases per Moores Law, their power requirement increases accordingly. This poses design challenges for their power supply module especially when they operate at sub voltage range. This paper presents a new multiphase topology that addresses these challenges. Laboratory tests on a hardware prototype of the topology shows improved load regulation, output voltage ripple and dynamic response time compared to a commercially available power supply module.