Analysis and Improvement of Incoming Power Quality at Cold Rolling Mill

Abstract

Electrical power is the most important power which is being used in modern industry, agriculture and daily life. With the development of industry, power require- ment is increasing. To fulfil the power demand, the size of power system is huge resulting into the more power quality disturbances which are mainly due to nonlinear loads. Power quality has aroused wide concern in recent years. Power quality has great in uence on safe and economic run of grid, reduction of energy consumption, guarantee of normal working of industry and scientific experiments. It is necessary to detect power quality disturbance events to improve power quality. Cold Rolling Mill (CRM) plant considered in this project receives its power from Main Receiving Sub Station (MRSS). CRM complex has different lines as CRM1 (Cold Rolling Mill 1), CTCM (Continuous Tandom Cold rolling Mill), CRCA (Cold Rolling Cold Annealing) CSPM (Continuous skin pass mill), BAF (Batch Annealing Furnace), Continuous Galvanising line, Pickling line. Due to the size and complexity of whole CRM complex, CTCM line is taken for the analysis. Initially a systematic system study was done by measuring the power factor, volt- age variations, harmonics and frequency uctuation etc. for definite range of time. Similar studies where done on UPS system also. IEC/IEEE standards are use for the analysis of the power quality at no load and full load. For the improvement of power factor, DSTATCOM (Distribution Static Compen- sator) is modelled and developed using simulink of MATLAB software. DSTATCOM is controlled using Synchronous Reference Frame (SRF) theory under nonliear load. Simulation results demonstrate that DSTATCOM is consider as a solution for power factor correction. DVR (Dynamic Voltage Restorer) is modelled and developed using simulink of MATLAB software. Simulation results show the mitigation of voltage sag and swell are possible by DVR. DSTATCOM and DVR have a large scope for improvement of power quality level.