Engineering Commons^™

Current-Source Dc-Dc Converter, Rocio Sanchez-Mendoza, Carlos Aguilar, Adrian Aranjo

Electrical Engineering

In this project, a hardware implementation of a current-source DC-DC converter for powering sensors used in an underwater communications system is presented. The proposed converter is designed to step down an input current of 0.9 A to 0.625 A, while maintaining an output voltage of 24 V and output power of 15 W. An overview of the system design is explained as well as the component selection process. The design of the converter was simulated and evaluated using LTspice before being physically constructed on a printed circuit board. Performance evaluation of the proposed converter was carried out in multiple lab …

Cascaded Linear Regulator With Positive Voltage Tracking Switching Regulator, Brandon K. Nghe

Master's Theses

This thesis presents the design, simulation, and hardware implementation of a proposed method for improving efficiency of voltage regulator. Typically, voltage regulator used for noise-sensitive and low-power applications involves the use of a linear regulator due to its high power-supply rejection ratio properties. However, the efficiency of a linear regulator depends heavily on the difference between its input voltage and output voltage. A larger voltage difference across the linear regulator results in higher losses. Therefore, reducing the voltage difference is the key in increasing regulator’s efficiency. In this thesis, a pre switching regulator stage with positive voltage tracking cascaded to …

Dc-Dc Converter Control System For The Energy Harvesting From Exercise Machines System, Alexander Sireci

Master's Theses

Current exercise machines create resistance to motion and dissipate energy as heat. Some companies create ways to harness this energy, but not cost-effectively. The Energy Harvesting from Exercise Machines (EHFEM) project reduces the cost of harnessing the renewable energy. The system architecture includes the elliptical exercise machines outputting power to DC-DC converters, which then connects to the microinverters. All microinverter outputs tie together and then connect to the grid. The control system, placed around the DC-DC converters, quickly detects changes in current, and limits the current to prevent the DC-DC converters and microinverters from entering failure states.

An artificial neural …

Energy Harvesting From Exercise Machines: Buck-Boost Converter Design, Andrew E. Forster

Master's Theses

This report details the design and implementation of a switching DC-DC converter for use in the Energy Harvesting From Exercise Machines (EHFEM) project. It uses a four-switch, buck-boost topology to regulate the wide, 5-60 V output of an elliptical machine to 36 V, suitable as input for a microinverter to reclaim the energy for the electrical grid. Successful implementation reduces heat emissions from electrical energy originally wasted as heat, and facilitates a financial and environmental benefit from reduced net energy consumption.

Improvements To A Bi-Directional Flyback Dc-Dc Converter For Battery System Of The Dc House Project, Michael Wu

Master's Theses

The DC House project relies primarily on renewable energy sources to provide DC power to the various loads of the house. However, not all renewable sources are capable of providing power at all times of the day. A back-up energy source in the form of a battery storage system must be available to meet the electrical needs of the house. A bi-directional flyback power converter was initially designed to allow a battery to charge from as well as discharge to the 48V bus line of the DC House. The design provided a 35W prototype to demonstrate the converter’s feasibility. Further …

Energy Harvesting From Exercise Machines - Dc-Dc Buck Boost Converter (Lt3791), Matthew B. Wong

Electrical Engineering

Cal Poly’s ongoing Energy Harvesting From Exercise Machines (EHFEM) project proposes sustainability and energy saving costs through modifying exercise machines generating DC power, providing a renewable energy resource through physical exercise. The EHFEM project contains multiple sub-projects involving modifying several different exercise machines. Each machine generates DC power and an inverter converts this power to AC. This AC power returns to the grid. This project addresses an issue involving a previously installed DC-DC converter not returning power properly. When generating DC power, the grid demands a specific AC voltage, but the generated power through the previous DC-DC converter and power …

Dc-Dc Converter Input Protection System For The Energy Harvesting From Exercise Machines (Ehfem) Project, Ryan Turner, Zack Weiler

Electrical Engineering

The ongoing Energy Harvesting from Exercise Machines (EHFEM) project at Cal Poly San Luis Obispo seeks to provide renewable energy without the high cost of implementation by harvesting DC power generated on machines used for physical exercise. The EHFEM project consists of numerous subprojects that involve converting different types of exercise machines for power generation. This project specifically works by scaling the output voltage from an elliptical machine using a DC-DC converter and sending it through an Enphase Micro-inverter to feed AC power back to the power grid and minimize energy spending. As a subset of the much larger project, …

Energy Harvesting From Elliptical Machines: Dc-Dc Converter Design Using Sepic Topology, Martin Kou

Master's Theses

Cal Poly’s ongoing Energy Harvesting from Exercise Machines (EHFEM) project is a very convenient and cost-effective way for generating DC power from physical exercise and sending it back to the electrical grid as AC power, providing a renewable energy source for the future. The EHFEM project consists of numerous subprojects involving converting different types of exercise machines for power generation. This project is a continuation of one of the previous subprojects, specifically involving an elliptical machine, and focuses on improving system functionality at different machine settings without altering the elliptical user’s experience by selecting a new DC-DC converter design, while …

Energy Harvesting From Exercise Machines: Bike Buck-Boost Converter, Monroe Diamond, Brian Vuong

Electrical Engineering

This project is a continuation of previous senior projects’ work on Energy Harvesting from Exercise Machines (EHFEM). EHFEM seeks an alternative DC to DC converter to function within the existing exercise bike system. Implementing this new DC to DC converter aims to avoid previous complications other groups encountered, such as only running at low load currents, exceeding an input threshold voltage to begin operation, and performing at low efficiency. In developing this self‐generating exercise bike, Cal Poly wishes to incorporate an array of energy‐harvesting exercise machines in its Recreation Center expansion scheduled for completion in 2012.

Energy Harvesting From Elliptical Machines: Dc Converter Troubleshooting, Michelle Lum, Jonathan Yuen

Electrical Engineering

In continuing the global effort to integrate innovative technology and renewable energy in the world’s power system, Cal Poly endeavors to harvest energy from elliptical machines and feed that power back into the electrical grid. This continuation of the previous project, Energy Harvesting from Exercise Machines Self‐generating Elliptical Machines, seeks an alternative DC to DC converter to function within the existing elliptical self‐generating system. By attempting to implement this new DC to DC converter, the project strives to reduce the size of the converter in order to mount it on the elliptical machine. The project also tries to explain how …

Improving Dc Power Supply Efficiency With Neural Network Controller, Weiming Li, Xiao-Hua Yu

Electrical Engineering

DC-DC converters can be found in almost every power electronics device. To improve the efficiency and controller response of a DC-DC converter to dynamical ~stem changes, neural network has been chosen as an alternative to classic methods. However, no prior work has been done in the neural network approach for control of a PSFB (phase-Shifted Full-Bridge) converter yet. In this research, a multi-layer feedforward neural network controller is proposed. The neural network based controller has the advantage of adaptive learning ability, and can work under the situation when the input voltage and load current fluctuate. Levenberg-Marquardt backpropagation training algorithm is …