Inverter Control on 3 Phase UPS System as Harmonic Compensator and Power Factor Improvement Using Online Combined Error Adaptive Fuzzy

Abstract

Uninterruptible power supply (UPS) is a form of electrical supply that is frequently used to regulate electrical current and perform as a backup power source when the primary power source fails. Apart from providing backup power, the inverter system proposed in this study can reduce harmonic effects and increase power factor. The control system is based on a synchronized reference frame (SRF) and uses online combined error adaptive fuzzy (OCEAF). The load voltage and current are decomposed into their symmetrical components: positive, negative, and zero. These components are then transformed to a synchronous reference frame (dq), which OCEAF controls. Controlling the inverter is accomplished by converting the controller output to abc coordinates. OCEAF combines the delta error adaptive fuzzy (DEAF) and the absolute error adaptive fuzzy (AEAF) techniques with the NN adaptor. This adaptive fuzzy-PI automatically modifies the Kp and Ki values when the system changes, significantly when the source value alters or is faulty. According to power factor measurements, OCEAF performance is superior, more consistent, and closely unity power factor. As for evaluating network harmonics, systems with OCEAF controllers may reduce network harmonics from 6.24 % to between 1 and 1.5 %. The DEAF and CEAF techniques reduce harmonics by 2- 2.5 and 1.5-2 %, respectively.