Posts

3 Weeks Remaining: Small Scale Prototype Wayside, Mechanism and Power Consumption

Image
I. ULTRACAPACITORS
1. Series Balancing Most modular way to balance UCAPs in our opinion is to use predefined PCBs.
https://www.ebay.com/itm/Six-In-Series-MaxWell-350F-2-7V-T11-T10-Supercapacitor-Balance-Protection-Board/263928360582?epid=1950825530&hash=item3d735b2e86:g:g-sAAOSwqrZa1pLZ:rk:2:pf:0
HOW TO USE THEM: https://www.youtube.com/watch?v=MdqJcrDiKN4&t=799s2 These devices limit the voltage and balance each capacitor. These PCBs can be combined to make a circuit with a combination of series and parallel:
2. MOSFET Charging Using MOSFETs to control the source current. We can quickly charge the UCAP bank within the confines of the maximum current ratings. When the voltage reaches 2.65V, the current will be controlled down to roughly 1A to allow the balancing PCBs to work and to prevent overcharging.

   a. Measuring Voltage across each UCAP The individual monitoring of each UCAP is essential in making sure it does not over charge. Measuring the voltage using an extended analog in…

4 Weeks remaining: Small Scale Prototype

Image
Wayside Power Small Scale Prototype:  Update 4 Weeks remaining

Issues this week:
Maxwell has still not gotten back to us, so we have begun to look for cheaper alternatives If we create a supercap bank made up with many 2.7V cells in combination of series and parallel, we will be able to save money.This does cause the charging time to increase to about 4 minuets, up from about 45 seconds, as each cell can only handle about 30A of current vs 2000A with the other more expensive modules.  We will have to solder all of these together. We will have to create a casing to hold and easily assemble, dissemble.  We can use SAB MOSFETS to balance our series stack and prevent overcharging instead of trying to match a mosfet of the shelf with our ucap modules, this is a good thing! These are specifically designed to be a low cost and low power usage solution to balancing supercaps in series.https://www.digikey.my/en/videos/a/advanced-linear-devices/using-mosfets-to-balance-supercapacitors-automaticall…

Goal: Small Scale Prototype

Image
GOAL Our team has started the beginning stages of creating a small scale prototype. We should see significant progress by the week of November 14th. Our goal is to create a complete working small scale prototype with 3D printed materials and small UCAPs. 
1.) UCAPs ISSUES CHARGING UCAPs IN SERIES An issue has risen when charging two UCAPs in series. Two conditions that may cause problems with series connection is: (1) UCAPs do not have the exact same capacitance due to manufacturing errors. (2) If the capacitors do not have the exact same charge when in series, it will cause one to charge faster than the other and potentially over charge a UCAP and cause damage or failure.  To avoid this issue when charging the SOLAR BANK, it is necessary to "balance.". From Illinois Capacitor Inc,