Waste harmonic power recovery from distribution transformer and its controlled consumption with battery support

Abstract

The increasing usage of non-linear loads in power distribution system has led to several power quality issues. The triplen harmonics due to non-linear loads are trapped in the primary delta winding of conventional delta-star configured distribution transformer. This unrecovered harmonics is usually wasted in the form of heat leading to excessive power loss and reduced life of transformer, and this wasted power is termed as drainage power. The recovery of drainage power is possible with star-star-delta_utilized distribution transformer. In this configuration, the power due to circulating harmonics can be recovered across the zero potential terminal of the delta winding. The extracted power is characterized by variable voltage and frequency. This paper presents the recovery of harmonic power from delta winding of star-star-delta_utilized configuration transformer and its controlled consumption with battery support for feeding the load. The powering of load and battery charging are with reference to State of Charge (SoC) of Lead-acid battery and the harmonic current magnitude in the tertiary.