Electric Vehicle Motor Controller

The heart of an electric car is the combination of:

The controller simply helps in driving the motor. Electric vehicular motors usually need drivers for commutation purpose (similar to DC machine). The vehicular motors which are usually BLDC does not have brush and commutator assembly for this. This is done by the inherent controller. The DC provided will be converted to a pulsed waveform in the driving circuit for driving the vehicular motor.

The electric motor
The motor's controller
The batteries

The controller takes power from the batteries and delivers it to the motor. The accelerator pedal hooks to a pair of potentiometers (variable resistors), and these potentiometers provide the signal that tells the controller how much power it is supposed to deliver. The controller can deliver zero power (when the car is stopped), full power (when the driver floors the accelerator pedal), or any power level in between.

In a car, the controller may takes in 300 volts DC from the battery pack. It converts it into a maximum of 240 volts AC, three-phase, to send to the motor.

The controller's job in a DC electric car is easy to understand. Let's assume that the battery pack contains 12 12-volt batteries, wired in series to create 144 volts. The controller takes in 144 volts DC, and delivers it to the motor in a controlled way.

In an AC controller, the job is a little more complicated, but it is the same idea. The controller creates three pseudo-sine waves. It does this by taking the DC voltage from the batteries and pulsing it on and off. In an AC controller, there is the additional need to reverse the polarity of the voltage 60 times a second. Therefore, you actually need six sets of transistors in an AC controller, while you need only one set in a DC controller. In the AC controller, for each phase you need one set of transistors to pulse the voltage and another set to reverse the polarity.

High speed BLDC motor controller is designed for electric motorcycles and electric scooters, equiped with powerful and intelligent microprocessor, up to 40000 electric RPM, compatible with 60 degrees or 120 degrees Hall position sensor and support any poles of brushless motor.