Conversion between electrical energy and mechanical energy is done by electrical machines. It is possible to use most of the electrical machines as motor or generator and also it is easy to switch between these states. This phenomenon makes them preferable in any dynamic application. Due to fast torque response, ease of control and efficiency; brushless DC machines (BLDC) are widely used in applications those need both acceleration and deceleration in operation, i.e. electric propulsion. This paper investigates features and scope of using a BLDC as a motor/generator.