Electrical vehicles have become more mainstream in recent years, and colleges and universities have been early adopters of the movement, constantly fueling the development and interest with student racing competitions. Two of the more popular events in student racing are the Formula Hybrid and Formula SAE races. Students of all backgrounds are drawn to these competitions because they represent the latest technology paired with a desire to save our planet by reducing our need for oil and gas.
When dealing with the power supply and the energy flow to the motors via complex inverter drives, it is important to note that we are not managing a small, 12VDC system—these systems can reach multiple hundreds of volts. In larger-scale vehicles such as busses and trucks, 1,000VDC seems to be a household number. Insulation is what contains these massive energy systems. To ensure that the insulation barrier does not break down in the harsh environment of driving, a special instrument called an IMI (Isolation Monitoring Interrupter) is mandatory in every electric vehicle (EV). These devices continuously read the resistance between the vehicle chassis and the high-voltage power system of the EV. If the resistance falls below a certain value, an alarm will be triggered, and the vehicle will need to be serviced immediately. If this occurs and the issue is not resolved before the race, then the situation would be deemed unsafe and the vehicle cannot race.