The best way to drive powerful DC Motor depends on the type of dc motor and the application requirements. A brushed motor that turns only one way, and doesn’t need braking may only need a PWM controller. A brushed motor that needs braking and reversing operation needs an H bridge along with the PWM. Sometimes the best way to drive a dc motor is just the cheapest way, if that suits the application. A brushless dc motor needs a 3 phase motor controller.
Through a high voltage 3 phase full wave rectifier system or 6 phase if available. A 3 phase rectifier of this kind typically uses 6 Silicon Control Rectifiers (SCRs) or similar devices.
Many people wonder what of the DC motor is best to drive an alternator. There is no electric motor that is best to drive an alternator, the system is power negative i.e. you get less power out of the alternator than you put into the motor driving it! That means you would be better just using the power source you were intending to drive the motor to drive the load that you were going to drive from the alternator.
There are several differences between a DC generator and a DC motor.
In DC motor we use emf or electrical energy to produce mechanical torq or energy. And DC generator does the opposite. It coneverts mechenical torq or energy to electical energy or electricity.
Do a simple experiment to understand this, the simplest example of DC motor and generator is the small DC motors usually used in toys, they are the simplest example of DC motor and generator.
If you connect it to batttery it works as motor and just take a small LED bulb amd join it to the two terminals of that motor and rotate it’s shaft you can saw a little glow in bulb that's where the motor is acting as a generator.
A starter is used in DC motors.
At instant starting of DC motor, back emf is zero. So if we apply rated voltage without starter, then starting current will be dangerously high. This high current will cause mechanical stress and also heats the winding and result in damage to windings.
Not only this, a sudden voltage drop will affect the other machines in same supply line. Hence to limit starting current, reduced voltage is applied with the help of starter during initial starting.
