User:Criveros0248/enes100/Electric Cars v.2

Link to project ekart v.2 team page.

Give instructor top 3 project choice list

 * 1. Electric Cars
 * 2. R.I.O.T. Wheel
 * 3. Electric Unicycle

Write problem statement
How can I develop an efficient electrical system for the ekart?

Assign Task1
Research speed controller assembly components.

Buy any other needed parts for the ESC System.

Look for more 12V batteries to make the ekart run on 48V instead of 12V.

Compare actual work done to Task1
I finished my research on the ESC system for the ekart. I needed to get contactors (continuous switches) for the ekart's circuit; luckily I found some in the forklift that used to house the DC motor. I tested the motor on 24V using the contactors and two batteries connected in series.

Week1 Narrative
On Monday of this week, I received the electronic speed controller and throttle pedal from China. I was surprised at the fast delivery they provided; it took about 5 business days for me to receive it in the mail.



I also researched the additional components that were needed for the ESC system of the ekart. I needed two contactors (a main contactor and a reversing contactor), a female junction plug, a male junction plug, and some cables. Because I did not know the function of contactors, I did some research and found out that they work like continuous switches used for prolonged contact periods. They also allow the electronic speed controller to reverse the motion of the DC motor if needed. They are recommended for an ESC system of this magnitude (48Vx46A=2.2kW) because they are hard wearing and have great conductivity. Because I knew there had to be some contactors in the forklift that housed the motor, I decided look for the ones I needed for the ekart's ESC system. After looking at the forklift's circuitry, I figured out which one was the main contactor and which one was the reversing contactor. I took those out of the forklift and used them to perform a test run of the donated 1.6HP DC motor running on two 12V batteries connected in series (24V total). Here's a video of the test run:

DC MOTOR TEST RUN

I also ordered the plugs and some LEDs for the ESC system. They should be arriving soon for me to complete the ESC system.

Week1 Peer Review
Peer review week 1

Assign Task2
Work on ekart's circuitry. Mount 1.6HP DC motor on ekart. Connect motor using modified drivetrain.

Compare actual work done to Task2
Mounted DC motor on ekart. Modified drive-train and attached motor to axle using bike chain and sprockets. Continued work on ESC system. Mounted car batteries on ekart's battery compartments.

Week2 Narrative
During this week, I continued working on the ESC system for the ekart. I decided to make a 5"x10" mount for the ESC assembly using 3mm thick steel sheet. I placed the main and reversing contactors, the 200A Kelly controller, and the reverse switch on the mount. I decided to bolt the ESC assembly beneath the steering wheel because it was the only spot where I had extra space. I also used an old steel supermarket basket to make the surface of the battery compartments on the ekart. I welded the flat surfaces for the battery compartments to the existing side battery arms and tested their strength by placing the heavy batteries on top of them. After the battery compartments passed their test, I worked on connecting the motor to the axle. I modified the drive-train using an old bike chain and two bike sprockets. I decided to go with a 1:1 ratio to transform the torque of the motor into a higher speed for the ekart. I made a mount for the motor using 3mm steel sheet and welded it to the ekart frame. I still need to figure out a way to reduce the vibration of the motor though because it gets really loud at high speeds.



Week2 Peer Review
Peer review week 2

Assign Task3
Finish all connections. Complete ekart's ESC circuitry. Sand and paint frame. Work on braking system; add a direct brake pedal to the left of the throttle pedal.

Compare actual work done to Task3
Worked on ESC system throughout the week. Sanded the frame to get it ready for black paint. Ordered additional parts.

Week3 Narrative
During this week, I worked on finishing up the ESC system for the ekart. I took my work from past week off the ekart to test it on a bigger area. I also wanted to be able to show all of my components and connections. I dismounted the motor off the ekart to connect it to the ESC system. I decided to go with a bigger battery system, so I decided to make a 36V power source using 4 batteries connected in series: I placed everything on the ground and began completing the ESC connections to the main contactor. I connected a precharge resistor and diode to the main contactor. I also finished the other connections to the battery and the motor from the contactor. I also replaced the small green LED bulb that I initially used for an LED strip that I had at home. I got rid of the reversing contactor and reverse switch after I realized my ESC does not fully support reverse controlling (I would need to buy additional components for $50.00). I also added a kill switch for safety purposes. Here's a picture showing all connections: After I completed the circuit and all connections were finished, I performed a power up. I also tried the 3-way pot TPS to make the motor turn, but it did not work. Later, I realized that I needed a hall effect sensor that essentially uses magnets and a 0-5V signal rather than a resistor that uses a 0-5K resistance signal. I tried to program the ESC by connecting it to my laptop. To do this, I had to disconnect the motor from the circuit. After I did this, I got an LED error. After reading the manual, I realized this LED error was in the manual and it was related to an incomplete ESC circuit. Later, I tried running the Kelly Controller programming software and plugged all the necessary cables, I was unable to program the ESC because I needed the right interface:Kelly RS232 converter; it should be arriving soon though.

Week3 Peer Review
Peer review week 3

Assign Task4
Finish ekart's minor details and record test run if possible.

Compare actual work done to Task4
Finalized work on ESC circuit. Tested ESC system using hall effect TPS. Worked on final materials list and tutorial. Worked on project team page. Unfortunately, I was not able to complete a test run because the 0.5" diameter axle bent and broke.

Week4 Narrative


This week, I received the hall effect TPS and the RS232 cable (programming interface) for the ESC. I connected the hall effect sensor to my circuit, performed a power-up, but still the motor did not rotate. After checking that my circuit was indeed correctly connected, I tried again but still no results. Then, I moved on to programming the controller using the right interface this time. I disconnected the motor from the circuit, and connected the ESC to my laptop using the RS232 cable. This time, I finally saw the programming software running for the first time. It's not a software that allows you to truly program the ESC but rather it's an easy-to-use interface that allows the user to input whatever values he/she wants in order to alter the performance of the ESC.



I also realized that there was no way of making the ESC circuit work with the TPS without first programming the ESC. First, I had to turn on the kill switch I had installed; then, I had to tell the ESC that the TPS I was going to use was the hall effect sensor. Finally, the most difficult part was picking the right voltage values (signal) for my 0-5V TPS to work. I had to do some more research online and found how to do this in an EV forum. Finally, I tested my ESC and I finally received the right output: the DC motor was now rotating and responding to my new TPS. I tried to record a test run after I mounted everything on the ekart and painted it black with spray paint, but unfortunately the rear axle was too weak and broke after placing the weight of the motor and my body on the ekart. I am going to continue working on the ekart as personal project though and will put a 1" solid axle instead of the 0.5" axle that broke in half. Finally, this week I also worked on a final materials list and a tutorial presentation for future ENES100 students to look at in case they want to work on a similar project. I wish I had finished this project sooner and showcased it in HCC to get further funding for future students who might want to work on this project. Unfortunately, I was working mostly by myself and did not have enough time and resources to complete it in 4 weeks.

Week4 Peer Review
Peer review week 4