Project

# Title Team Members TA Documents Sponsor
7 Optimized Solar Charging off grid for several output voltage potentials
 Kanin Tangchartsiri
Lukas Gollings
WonJoon Lee
 Akshatkumar Sanatbhai Sanghvi design_document3.pdf
final_paper1.pdf
other1.pdf
photo2.jpg
photo1.jpg
presentation1.pdf
proposal1.pdf
**Project:**

Optimized Solar Charging off the grid for several output voltage potentials

**Team Members:**

Lukas Gollings (lwg2); WonJoon Lee (wonjoon2); Kanin Tangchartsiri (kanint2)

**Problem:**

With technological advancements, our lives have tremendously changed and became more convenient. However, the environmental issues followed with the advanced tech and renewable energy sources remain as a topic of interest. There are lots of efforts to reduce carbon footprint ranging from installing solar panels to developing more efficient methodologies to save electricity. For people who cannot install solar panels, they may want alternative ways to use renewable energy without a need for the grid.

**Solution:**

Our team proposes a solar panel integrated with a cascaded DC-DC Converter capable of providing multiple voltage outputs. We are looking to create charging capabilities for a multitude of different devices with different ratings (for e.g. AAA batteries, AA batteries, a smartphone) all within the same charging station. The overall product will look similar to a point of sale, whereby the stand itself is able to accommodate multiple devices (depending on the size and budget for our solar panel). Typical applications for this would include setting this device up to run in remote locations that are off the main grid which will allow the user to have access to a charging unit that’s portable for off-grid adventures like camping or hiking. The overall project is focused on displaying how much energy the users have saved.

**Design Specifics:**

DC-DC converters will be controlled using the duty cycle to replace (variable) resistors. In addition to this, for the accurate record of power savings, overall output energy used during the charging process will be monitored. For the most efficient power delivery, our design will have two DC-DC converters cascaded together, such that we can extract power efficiently from the solar panel and store this energy to be used when needed. The secondary DC-DC converter will regulate the intermediate voltage of the storage unit, and further provide galvanic isolation. We might need a 4 winding transformer, to provide galvanic isolation from the intermediate storage unit and the output batteries. This is a crucial step for the user's safety and also to ensure freedom of series connection at the output. In addition, this will be a good practice to reduce the common mode noise for the output reliability. We’ll also utilize MPPT algorithms to make sure that we have optimized our input power into the system and possibly as an extension project we can also have the unit track sunlight for maximum exposure.

**Solution Components:**

1. Input: Solar Panel Power Voltage Input (Solar Panels)
- Cost effective, efficient, and portable
- Commercially available solar panels on digikey are only rated at 1-2 [W], would need to create an array of solar panels to reach 10 [W] on output side

2. Synchronous Buck/Boost Converter

- Control schema to regulate the power being extracted from the solar panel
- Microprocessor creates duty cycle to regulate the intermediate voltage potential in the energy storage unit. The actual energy storage unit will be an off the counter mobile power bank to reduce complexity of a self designed battery.

3. Design of energy transfer process

- Need for appropriate voltage regulators to quantify the amount of power received from the solar panel
- Current Transducer (CT) and/or regular current sensors can be utilized to monitor that output and the calculations of power consumption will be done on our MCU.
- We can store our energy within a small scale power bank (over-the-self portable power bank) that should allow us to keep reserves of the energy.
- Stable intermediate voltage potential using a custom designed micro controller unit.

4. Secondary DC-DC Converter for several outputs

- Use of transformers to provide several different output potential voltages
- Analog USB power supply design

5. Output: Distribution of different voltage potentials for charging.

- Using the rechargeable batteries ordered, we will ensure the output potentials are restricted to the recommended current for charging.

**Criterion for Success:**

- Accurately display power output of the unit for users to see.
- Optimizes the efficiency of the solar panel unit to the maximum rate with our MCU.
- We aim to have an efficiency of 10% taking account of the losses in solar panels and other energy losses through some passive components. This number is relative to the input power from solar energy. If we’re talking about internally, we’re expecting an efficiency of approximately 80%.
- Able to charge differently rated devices, minimum of 3 different ratings (1.2 [V] at 700 mA (or 10% of mAh rating) , 2.4 [V] at a minimum of 1 [A] 5V at 2 [A] ). https://www.digikey.com/en/products/detail/panasonic-bsg/HHR-75AAA-B/655447 (standard AAA rechargeable battery)

**Current Competitors and Designs:**

- https://www.amazon.com/Anker-Charger-PowerPort-iPhone-Galaxy/dp/B012YUJJM8
- These don’t make use of optimized algorithms to maximize efficiency and overall power output. They also do not account for differences in loads and overall demand that’s been plugged onto the device.
- Users have experienced problems with the voltage regulator causing unstable charging speeds. We would aim to maintain constant charging speeds, while recording how much energy has been stored in the intermediate battery regulator throughout the devices’ lifetime.

Resonant Cavity Field Profiler

Salaj Ganesh, Max Goin, Furkan Yazici

Resonant Cavity Field Profiler

Featured Project

# Team Members:

- Max Goin (jgoin2)

- Furkan Yazici (fyazici2)

- Salaj Ganesh (salajg2)

# Problem

We are interested in completing the project proposal submitted by Starfire for designing a device to tune Resonant Cavity Particle Accelerators. We are working with Tom Houlahan, the engineer responsible for the project, and have met with him to discuss the project already.

Resonant Cavity Particle Accelerators require fine control and characterization of their electric field to function correctly. This can be accomplished by pulling a metal bead through the cavities displacing empty volume occupied by the field, resulting in measurable changes to its operation. This is typically done manually, which is very time-consuming (can take up to 2 days).

# Solution

We intend on massively speeding up this process by designing an apparatus to automate the process using a microcontroller and stepper motor driver. This device will move the bead through all 4 cavities of the accelerator while simultaneously making measurements to estimate the current field conditions in response to the bead. This will help technicians properly tune the cavities to obtain optimum performance.

# Solution Components

## MCU:

STM32Fxxx (depending on availability)

Supplies drive signals to a stepper motor to step the metal bead through the 4 quadrants of the RF cavity. Controls a front panel to indicate the current state of the system. Communicates to an external computer to allow the user to set operating conditions and to log position and field intensity data for further analysis.

An MCU with a decent onboard ADC and DAC would be preferred to keep design complexity minimum. Otherwise, high MIPS performance isn’t critical.

## Frequency-Lock Circuitry:

Maintains a drive frequency that is equal to the resonant frequency. A series of op-amps will filter and form a control loop from output signals from the RF front end before sampling by the ADCs. 2 Op-Amps will be required for this task with no specific performance requirements.

## AC/DC Conversion & Regulation:

Takes an AC voltage(120V, 60Hz) from the wall and supplies a stable DC voltage to power MCU and motor driver. Ripple output must meet minimum specifications as stated in the selected MCU datasheet.

## Stepper Drive:

IC to control a stepper motor. There are many options available, for example, a Trinamic TMC2100. Any stepper driver with a decent resolution will work just fine. The stepper motor will not experience large loading, so the part choice can be very flexible.

## ADC/DAC:

Samples feedback signals from the RF front end and outputs the digital signal to MCU. This component may also be built into the MCU.

## Front Panel Indicator:

Displays the system's current state, most likely a couple of LEDs indicating progress/completion of tuning.

## USB Interface:

Establishes communication between the MCU and computer. This component may also be built into the MCU.

## Software:

Logs the data gathered by the MCU for future use over the USB connection. The position of the metal ball and phase shift will be recorded for analysis.

## Test Bed:

We will have a small (~ 1 foot) proof of concept accelerator for the purposes of testing. It will be supplied by Starfire with the required hardware for testing. This can be left in the lab for us to use as needed. The final demonstration will be with a full-size accelerator.

# Criterion For Success:

- Demonstrate successful field characterization within the resonant cavities on a full-sized accelerator.

- Data will be logged on a PC for later use.

- Characterization completion will be faster than current methods.

- The device would not need any input from an operator until completion.

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