GRAMM
Team members:
- Geoff Sanders
- Richard Tan
- Ankit Tripathi
- Maung Myat
- Marc Hesse
The purpose of this project is to design and construct an electrical machine that will serve as both the starter and alternator in an automobile. The machine must be capable of delivering 30 Nm of starting torque during motoring and generating 1kW at 3000 rpm. The machine must motor from standstill to 3000 rpm in 3-5 seconds. At cruising speed (3000 rpm) the machine will charge a set of batteries. The machine will be powered by a 200 V dc supply. There will also be a user interface allowing the user to start up or shut down the system and display pertinent data about how the machine is operating. The main objectives as set forth by the International Future Energy Challenge (IFEC) are:
- $100 total cost for electric machine and controller for mass production.
- Safety and fault tolerance to cope with failures in the machine and controller.
- An efficiency of no less than 75%.
- Smooth transition from motoring to generating or vice versa.
- Power-electronic based controller (inverter/rectifier).
- NEMA frame 56C size.
This will be accomplished by designing a pole changing induction machine utilizing 8 poles during start-up and 4 poles during generating. A PWM inverter that will consist of six IGBT or MOSFET switches will be employed as the motor controller. This inverter must also serve as the rectifier during generation mode. The control of the switches as well as the pole changing will be implemented with a micro controller DSP chip. This DSP could also potentially serve as the system controller. If it will not work in this capacity we will need a second DSP to collect, calculate, and display data concerning the operation of the machine.