Self-compensation with trapezoidal six step control of BLDC Motor for hoist applications

Abstract

This paper presents Self-compensation with trapezoidal six step control for improving the performance.  The Brushless dc motors rotor has permanent magnet which rotates around fixed armature. The current in armature is commutated to give rise to rotation. The commutation angle error reduces the efficiency and performance of the motor. The back EMF waveforms are taken based on the relationship between commutation point shift and the difference of the dc-link current. Based on these relationships the analysis is made under ideal, advanced and delayed commutations resulting in the reduction of the commutation phase shift errors. In this paper presents Compensation method with six step control used to  eliminates the impact caused by commutation ripple by delaying the commutation improving the dynamic performance  when compare with conventional methods. The project proposes a BLDC motor that can be used for its application in hoists or cranes. Most of the commercial system uses induction motor where power drops at low loads and also starting torque is poor. When compared to induction motors BLDC motor has high efficiency and high energy saving with low start up current capacity, as it is powered by DC electric source and the switching power supply produces AC supply to drive the motor, hence BLDC motor has higher torque ratio for its application in industries and also positioning and controlling is possible which is more efficient in BLDC than in induction motors.