Improvement of power quality and reliability in the distribution system of petrochemical plants using active power filters

Abstract

Variable speed drives (VSDs) are used extensively for pumping/compressor operations in petrochemical plants of the Jurong Island in Singapore. The VSDs draws harmonic current from the mains which causes power quality issues in the system. Passive harmonic mitigation techniques, 12-pulse/24-pulse transformers are being used in the petrochemical plant to minimize the voltage/current harmonics because of their lower cost and higher reliability, but these methods are less efficient. This paper investigates the power quality and reliability improvement in the petrochemical plants by using active power filters (APFs). The study has been conducted in the petrochemical plant distribution system by connecting an active front end (AFE) converter and shunt active power filter (SAF) with the 6-pulse drive system in place of conventional 12-pulse rectifier-drive system. Simulation were carried out in MATLAB/Simulink environment for 1 MW drive system with 12-pulse rectifier, 6-pulse rectifier with the SAF and the system with AFE. Subsequently, reliability assessment has been carried out for the three test systems under study in DIgSILENT Power Factory simulation software. Harmonic mitigation methodologies are verified through a down scale experimental laboratory setup of 7.5 kW motor drive system to check the effectiveness active harmonic mitigation methodologies.