Race Strategy. What do we need to do to make the car as fast as possible? Greenpower schools education event, Castle Bromwich 1 st May 2013 Dan Lloyd & Robin Boyd. Introduction. Race Strategy is made up of our Powertrain and Electrical teams
What do we need to do to make the car as fast as possible?
Greenpower schools education event, Castle Bromwich
1st May 2013
Dan Lloyd & Robin Boyd
Simulation & Strategy:
Driven vehicle simulation – Vicente
Motor dyno and losses – Dan
Understanding Batteries – Robin
Race Strategy – Simulation & Strategy
Working out how fast and far we can go before we get there
↑↑ Gear Ratio
↓↓ Gear Ratio
Which Gear Ratio?
Test and simulation will help you decide
Race Strategy – Motor and Losses
A quick guide on how to prevent your motor from melting
Example of a 2 pole motor
Example of a (broken) Fracmo motor
BUT moving a charged wire through a magnetic field induces a voltage that opposes the supply.
These reach an equilibrium and a maximum speed is reached
Power = Current x Voltage
(Watts) (Amps) (Volts)
For a 24V motor running at 20A the power used is 480W
This is higher than the motors rated power!
We can do the same to measure power out from the generator and calculate the efficiency.
Now it’s your turn!
So the power in was more than the power out…
The energy must have gone somewhere
All these losses mean that the motor draws more current to run at the same speed…
And more current means more heat!
How do we reduce current?
Race Strategy – Batteries
Squeezing the most from your cells
How can we get more out of them?
11.2kg, 12V, 32AH
Fixed current at 28 Amps