Comparative analysis of custom power devices for power quality improvement in non-linear loads

In the power system, nonlinear loads results in production of harmonics due to which load current waveform gets distorted. This gives rise to production of current harmonics from load side and they tend to flow towards the source through Point of Common Coupling (PCC). These current harmonics further gives rise to voltage harmonics on the source side due to which nearby consumers can be affected. Thus, it is recommended to control the current harmonics on the load side itself at PCC so that they cannot interfere with the neighbouring loads. So, to avoid power quality problems at the source, custom power technology is being adopted in which number of control techniques are used to improve power quality. In this paper, an attempt has been made for selection of various such custom power devices like Distribution Static Synchronous Compensator (DSTATCOM), Static VAR Compensator (SVC), Dynamic Voltage Restorer (DVR), Unified Power Quality Compensator (UPQC) for the improvement of power quality in manufacturing industries. Then a characteristic comparison of these devices has been done. The limits imposed by IEEE and IEC standards for power quality improvement have also been discussed.