Comparative analysis of differential delta configured 18-pulse ATRU

With the advancement in technology, in order to use simple and effective technique for reducing harmonics in the input supply current, multi-pulse techniques are widely being used in high power applications like aircrafts electric power systems and in the electrochemical industries. For systems where isolation is not a major concern, multi-pulse converters provide the best solution. With the increase in pulse number, Characteristic Harmonics are greatly reduced but, at the cost of complexity and expenses. In this paper, two differently wound 18-pulse Differential Delta configured Auto Transformer Rectifier Units(ATRU) are being analyzed and discussed here. Their operating principle is analyzed; the harmonics analysis of the input ac current and output dc voltage of the ATRUs is done, the RMS of every winding are calculated. Simulation models were built in MATLAB in order to see the results of both the systems, and at the end, for the complete evaluation and experimental verification, 2kW Power experimental prototype was built.