Analysis on the failure of dynamic braking of capacitor-run induction motor supplied from half-controlled converter

Abstract

This paper examines the viability of applying dynamic braking to AC voltage controller supplied capacitor-run induction motor. During the variable speed operation, the AC voltage regulator is gated during both half-cycles of the supply voltage. It is proposed to effect dynamic braking of the motor by inhibiting firing pulses during the negative half-cycles of the supply voltage. This will lead to half-controlled converter operation applying DC voltage across the motor terminals, and is supposed to cause dynamic braking. Contrary to expectation, motor is observed to rotate at a very low speed instead of braking. Theoretical, computed and measured results are presented in this paper to explain the failure of dynamic braking.

Brake failure detection and electronic auxiliary braking system

“…[2] In the case where there is no change in pressure, i.e. pressure loss, for a certain period of time a break failure is indicated with the help of the pressure sensor (BMP180) which causes the display indicator to show break failure and shifts it from automatic mode to manual mode and simultaneously the buzzer goes on and thus gives an audio indication as well [3]. Now in the manual mode the driver can control the car manually by pressing a button via a keyboard, which will cause the change in speed by 80%, 50%, and 25%and slowly causes it to stop.…”