30 October 2019

We were able to meet with Dr. Ping Hsu earlier this week to discuss our current power module design. We were given the idea of incoporating DC/DC converters into our system to better regulate the current flow of the system. After discussing our finding to Dr. Furman, we later decided to use a DC/DC converter to charge the battery in our power module. Our supercapacitors will be used to slowly charge the battery pack in the system. 

For the following week, we will try to meet with Dr. Saeid Bashash to furthur discuss our design and hopefully obtain answers to some of our current design. We have also decided who will be speaking at Podcar City event next week. 

23 October 2019

In the past week, we have completed our simulations that predict the behavior of the supercapacitor system. Due to our lack of experience in this subject, we will meet with an expert on in the coming weeks to confirm our findings. Our simulations concluded that quickly charging our system is achievable. Since we are only using 16 series and 1 parallel configuration, we predict that an inrush current of 35.1 Amps is needed to achieve fast charging. Referencing to our current charger from Howland Technology, the charger is able to output 36V and 33 Amps. Therefore, we conclude that fast charging is achievable.

We also created a simulation that predicts the discharge and power output of the supercapacitors. We found our power output to be around 1200W. Therefore, we decided that a motor with a power rating bigger than this number is needed. Next, we considered if this power output is enough to move our system. We used electric scooters as a reference. An electric scooter usually uses 1200W of power. Since the weight of our systems will weigh less than a human being, we determine a motor with a power rating of 1500W is sufficient for this project. Lastly, we present our findings to the whole team. The presentation is attached below. Simulations are also provided inside the presentation.

Presentation 2 from Steven Goh

16 October 2019

Much of this week revolved around understanding the wiring and different components of the current power modulus. We were able to dissaemble the power modulus and map out a majority of the wirings. We were also able to gain a better understanding of the power source provided by the team from last year. In order to operate the power source, it must be connected to a working BMS which we are working on correcting

We are also considering creating a battery pack for charger input instead of using a wall outlet. We figured that a wall outlet has certain limitations. In addition, we are cordinating with the wayside team to pick a sufficient motor for our final demonstation. If we are to use 16 capacitors in series, we figured that 1500 W motor should be sufficient. We figured that the whole system won't be heavier than a human being. For reference a skateboard hub motor usually need 700W of power. Integrating a 1500W of motor should be more than enough to run our system. 

9 October 2019

In the past week, the team concluded that Eagle would be the best design software for PCBs for the project.  The team consulted with Dr. Furman about determining various specifications for the power modules system.  This included the torque for the motor, the radius of the wheel, and the mass of the bogie and/or cart.  Depending on the size of the motor and the amount of torque that can be delivered by that motor, more or less may be required.  If more motors are used, more torque will be delivered, which would accelerate a certain mass even more.  Dr. Furman also suggested designing at a couple different scales, for experimentation before going full-scale.  Specifications for the voltage required, current, mass, and box dimensions for the housing of the power module were also discussed. 

The team also consulted with the Wayside Power team to determine the appropriate next course of action.  The Wayside team informed us that they will be making a rapid prototype, and the full-scale will be designed off of the rapid prototype.  Confusion regarding the sizes and requirements of motors, cart dimensions, and design decisions were cleared up. 

For the coming week, more research will need to be conducted before deciding upon certain specifications.  Familiarization with Eagle for PCB schematic and layout design will need to be conducted among the team as a whole.  Part of the team will meet with Tynan today, to gain more knowledge about last year's design and system, and learn about why certain decisions were made.  Also, the team will need to find if there are more Maxwell Technology supercapacitors to experiment with. 

2 October 2019

This past week, the team continued researching for supercapacitors, and how they can be combined with batteries.  Further discussion of system specifications was considered, such as how much current the system will need to reach 48V to power the bogie to accelerate the bogie and get it to cruising speed, and the optimal resistance value for the system.  Also, the integration of PCBs and their design was discussed.  More research will be conducted in the coming week.  

The team met with the Power Wayside team to discuss the power charger that last year's team received last minute.  It was concluded that the power charger would be the responsibility of the Wayside team since it had more applications with them.  The platform for carrying the arm and the power modules was also discussed, but no definite specifications have been made, other than the length of the third rail, which has been said to be 20ft but is subject to change.