An improved DC/DC converter with reduced voltage stress and filter circuit for PMDC motor drives

This paper focuses on an improved DC/DC converter with a novel soft switching technique to improve the conversion efficiency for wide load range and high voltage applications. A five level inverter topology is proposed during the first stage of conversion process which reduces the voltage stress across the switching devices to 1/3 rd of the input voltage thereby reducing the voltage rating of the device for high voltage applications. The proposed topology is designed for industrial drive applications. The modulation strategy for the proposed topology is developed using Secondary side phase shift (SSPS) control technique. In addition, this scheme exhibits soft - commutation (ZVS) for both the primary and secondary side switches which minimizes the switching losses to a great extent. Further, the Permanent Magnet DC Motor is mathematically modeled in this work which provides the output more equivalent to the real time applications. The PMDC motor is made to run at its rated speed and the simulation results thus obtained are discussed in detail. The operation of the DC/DC converter used in industrial drive applications is analyzed using, the modeled Permanent Magnet DC motor. The proposed circuit is simulated using MATLAB 7.10.0 (R2010a) version.