Passive techniques for reducing input current harmonicsDownload Now
Events over the last several years have focused attention on certain types of loads on the electrical system that result in power quality problems for the user and utility alike. Equipment which has become common place in most facilities including computer power supplies, solid state lighting ballast, adjustable speed drives (ASDs), and uninterruptible power supplies (UPSs) are examples of non-linear loads. Adjustable speed drives are also known as variable frequency drives (VFDs) and are used extensively in the HVAC systems and in numerous industrial applications to control the speed and torque of electric motors. The number of VFDs and their power rating has increased significantly in the past decade. Hence, their contribution to the total electrical load of a power system is significant and cannot be neglected.