CRM flyback topolojisi ile yüksek güç faktörü ve düşük toplam harmonik bozulmalı yeni bir LED sürücü tasarımı

In many of today's solid-state lighting (SSL) applications, Critical Conduction Mode (CRM) Flyback PFC converter is a popular solution due to its limited component count and simple structure with respect to other switched mode power supply (SMPS) topologies. As described in international standards documents (IEC/EN 61000-3-2), LED drivers are required to demonstrate a power factor results greater than 0,9 and lower total harmonic distortion (THD) for power levels above 25W. Due to nonsinusoidal input current waveform of the traditional constant-on time control method, achieving improved PF and THD is quite difficult. In this thesis after introduction to LED lighting and switch mode power supplies, a new control method is introduced in an effort to improve power factor and total harmonic distortion of Voltage Mode CRM Flyback PFC Converter. The work proposes injection of a compensating sin(𝑤𝑡) signal component in the feedback path utilizing an additional primary transformer winding to linearize the current from the source. The detailed theoretical analysis is presented along with measurement results of a 30W prototype.