Tepe Akım Kontrol Modunda Çalışan SEPIC DA/DA Dönüştürücünün Tam Çözümlü Sembolik Zayıf Sinyal Analizi

 Bu makalede tepe akım kontrollü izolasyonsuz SEPIC dönüştürücünün tam çözümlü küçük sinyal analizi sürekli iletim modunda "pwm switch" modeli vasıtasıyla sunulmuştur. Makalede sunulan analiz SEPIC dönüştürücünün çıkış geriliminin kontrol gerilimine oranından oluşan transfer fonksiyonunun sıfır ve kutuplarını topolojideki 4 reaktif elemanının iç dirençlerini içine katarak sembolik formda gösterir. Analizi yapılan transfer fonksiyonu 4. dereceden pay ve 5. dereceden paydadan ibaret olup, transfer fonksiyonun sıfır ve kutuplarının sembolik formüllerinin elde edilmesi için belli şartlar altında yaklaşıklık yapılması zorunludur. Sembolik formda türetilmiş olan transfer fonksiyonunun doğruluğu gerilim yükselten ve gerilim düşüren çalışma modlarında iki ayrı sayısal örnek üzerinde gösterilmiştir. Bu sayısal örneklerde ortalama devre modelleri vasıtasıyla yapılan frekans domeni PSpice devre benzetimleri ve zaman domeninde yapılan LTspice devre benzetimlerinin sonuçları karşılaştırılmıştır. SEPIC dönüştürücünün transfer fonksiyonunun matematiksel analizleri, PSpice ve LTspice devre benzetimleri ile laboratuvar ölçüm sonuçları birbirlerini desteklemeleri göstermektedir ki makalede analizi sunulan transfer fonsiyonunu başarılı bir şekilde türetilmiştir.

Full Order Symbolic Small Signal Analysis of Peak-Current-Controlled SEPIC by PWM-Switch Model

Full order small signal analysis of peak-current controlled non-isolated Single Ended Primary Inductor Converter (SEPIC) is presented by utilizing pwm-switch model in Continuous Conduction Mode (CCM). The analysis provides control to output voltage transfer function together with its zeros and poles in symbolic form taking into account parasitic resistances of all four reactive components in the SEPIC topology. The resultant transfer function is with 4th order numerator and 5th order denominator, which necessitates approximation in deriving formulas of zeros and poles in symbolic form. Symbolically derived transfer function of the SEPIC is validated on two different numerical examples, one with operating in step down mode and another operating in step up mode, by frequency domain PSpice simulations on average circuit models and by time domain LTspice simulations on switching models. The mathematical analysis, PSpice and LTspice simulations, and measurement results of control to output voltage transfer function of SEPIC agree very well proving that the symbolic control to output voltage transfer function of SEPIC together with its zeros and poles are successfully derived.

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