An Adaptive Delay Compensated Position Sensorless PMBLDC Motor Drive With Regenerative Braking for LEV Application

Abstract

This paper deals with a new terminal voltage-based rotor position sensorless algorithm of permanent magnet brushless DC (PMBLDC) motor with adaptive phase angle compensation along with regenerative braking technique for light electric vehicle (LEV) application. Removal of Hall-Effect sensors from PMBLDC motor reduces the circuit complexity and makes the motor drive system robust and compact. Back EMF based position estimation of PMBLDC motor suffers poor accuracy at low speed. In this paper, position sensorless operation is achieved at very low speed below 100rpm. Position estimation of PMBLDC motor suffers with commutation error due to several factors like non-ideal back EMF, lowpass filter used, unbalanced DC bus voltage etc. An adaptive phase angle compensation strategy is developed to mitigate this issue, considering a generalized nonideal commutation case. This method is suitable for compensation of commutation error during variable speeds over a wide speed range, which is required for EV application. Moreover, the compensation method works with motor parameters variation as well. The proposed drive topology extends the vehicle's driving range with solar PV integration and energy regeneration algorithm. The system is simulated and experimentally validated in real case scenarios.