Design of Control Secheme and Performance Improvement for Multilevel Dc Link Inverter Fed PMBLDC Motor Drive

Abstract

PMBLDC motors are gaining a lot of popularity due to their high efficiency as the Permanent Magnets do not carry current which results in negligible copper losses as compared to asynchronous motors. This paper introduces a design for speed control of the PMBLDC motor using multilevel dc link inverter fed by a Boost Converter. The multilevel dc link inverter consist of five level voltage sources, which are controlled by switches. The motor can be driven at different speed level as per its load requirement by making use of five level MLDC Link Inverter. In case of traditional inverter which is only a one level inverter the speed cannot be controlled as per the load requirement. The MLDC link inverter provides the output voltage waveform in step shape form. Thus as the number of cells (n) increases output voltage touches the fundamental component. The input voltage is low, thus to increase the input voltage given to the MLDC link inverter the (Boost Converter) has been designed. The Boost Converter is placed in between (DBR)Diode Bridge Rectifier and (MLDCLI). Both the design and results of Single level inverter and Multilevel Dc Link Inverter are obtained and compared by using the MATLAB Software along with the use of Simulink and Simpower system Tools.