Equalization of the Current in a Three-Phase Electrical Power System

Abstract

Single phase loads connected to three phase systems creates unbalance in the system. This paper aims at the development of certain techniques that could divide the power drawn by a single phase load to the three phases of a three phase system according to the current amount at which each phase is loaded. For accurate controls and power division, we use a DC link connected with converters at both the ends. The power flow is controlled by implementing controlled rectification in each phase. PWM inverters are used to produce perfect sine waves from this DC rectified output, and thus creating a controlled single phase supply from the three phases. The firing pulses for the thyristors are provided by a PIC microcontroller. Three Phase power converter found applications in every field of life where single phase loads are fed from a three phase supply. Implementing in domestic use can definitely keep the balance of the system even under severe neutral shifts due to failure in system. It increases the balance of the system whenever a new single phase load is operated in the system - just the opposite of what conventional methods do. It can also replace three phase wiring with a single phase wiring, hence cost effective and can drive heavy single phase loads such as X-ray machines, Induction burners etc. by replacing bulky and inefficient systems like phase reduction transformers and improving the balance of the system.