Bagaoisan, Leah Joyce M. <br/><br/>
Total harmonic distortion mitigation in matrix converter ups using fuzzy-logic based active power filter/ 
Leah Joyce M. Bagaoisan, Danniel Jhay S. Larida, John Clemence Magtulis, Joshua Reyes, Andrea Crisanta G. Sang-olan, and Grace Ann O. Señagan.-- 
 - Manila:  Technological University of the Philippines,  2025. 
 - xii, 133pages:  29cm. 
<br/><br/> Bachelor's thesis<br/> 
<br/><br/>College Of Engineering.--    
<br/><br/>Includes bibliographic references and index. 
<br/><br/> Low waveform distortion and sustained power delivery under dynamic load<br/>conditions are two things that traditional UPS systems frequently fall short of. To fill these<br/>gaps, this study assesses an Uninterruptible Power Supply (UPS) based on a Single-Phase<br/>Matrix Converter combined with a Fuzzy Logic-Controlled Active Power Filter (FL-APF).<br/>Tests of battery duration under 20%, 60%, and 80% load conditions showed that runtime<br/>and load demand were inversely correlated. The system maintained a steady voltage output<br/>of 228.30V and minimal battery discharge (12.61V to 12.12V) for 2 hours and 47 minutes<br/>while operating at a 20% load (54W). The system's runtime decreased to 1 hour and 12<br/>minutes at 60% (181.6W) and only 29 minutes at 80% (231.3W). The UPS continuously<br/>maintained output voltages close to the nominal 230V and recovered efficiently after<br/>operation, even though heavier loads increased inverter stress. Additionally, an analysis of<br/>Total Harmonic Distortion (THD) at various load levels revealed increasing distortion:<br/>2.2361% at no load, 2.3259% at 20%, 2.7731% at 60%, and 3.1305% at 80%. The efficacy<br/>of the fuzzy-logic-based APF was demonstrated by the fact that THD stayed within the<br/>target threshold of ≤3% even during peak conditions. Significant improvements in<br/>waveform purity when connected via UPS were confirmed by additional device-specific<br/>THD evaluations. When non-linear loads were tested, the THD of an HP laptop decreased<br/>from 8.36% when connected directly to the grid to 3.17% when using a UPS; the THD of<br/>a Dell laptop decreased from 12.03% to 3.42%; and the THD of an audio amplifier<br/>decreased from 10.60% to 3.12%. These improvements validate the system’s real-time<br/>harmonic suppression capability and its suitability for powering sensitive electronics. 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Uninterruptible power<br/>Inverter stress<br/>THD analysis
<br/><br/><label>LC Class. No.: </label>BTH TK 146  / B34 2025