The Boost inverters are intended to be used in system like uninterruptible power supply (UPS), where an ac output voltage should be larger than the dc input voltage. Such inverters need more number of switches and two stages of power conversion. This work proposes a novel dc to ac boost based on sinusoidal-pulse-width-modulation (SPWM) control which generates output in single stage and whose peak value can be greater than the dc input one depending on the instantaneous duty cycle. This property is not found in the classical VSI, which produces an ac output voltage always lower than the dc input voltage. The proposed inverter performs single stage power conversion, which minimizes switching losses and attains higher efficiency as compared with conventional boost inverter, in spite of the 35% reduction in the number of switches. This paper describes a new PWM strategy for proposed boost inverter. This modulation strategy reduces the energy loss and harmonics in the proposed inverter. This technique allows the proposed inverter to become a new feasible solution for many applications like PV systems, automotive electronics, solar home applications and other power supply systems.

Design and performance analysis of novel boost DC-AC converter

Bu calismada, bir ruzgâr turbini ve fotovoltaikten olusan hibrid guc sistemi icin, hem sebekeye parelel ve hem de sebekeden bagimsiz olarak calisabilen bir evirici tasarimi gerceklestirilmistir. Tasarlanan tek fazli evirici icin, darbe genislik modulasyonu kullanarak bir mikrodenetleyici yardimi ile PWM darbeleri uretilmistir. Tek fazli evirici devrenin tasarimi yapilmis olup, evirici devreyi kontrol etmek icin C32 dilinde, bir kaynak kodu yazilmistir. Tasarimda, DSP tabanli bir mikrodenetleyici kullanmanin ana amaci, darbe genislik moduleli isaretler uretmektir. DSP tabanli bir mikrodenetleyici kullanimi, devrenin ucuz, boyutlarinin kucuk olmasini ve donanimda bir degisiklik yapmaksizin kontrol algoritmasinda degisiklik yapmaya olanak vermektedir. Evirici cikisi yuksek verimli olarak tasarlanmistir. Yapilan calisma sonucunda, Microchip firmasinin, dsPIC32MX795F512L mikrodenetleyicisi kullanilarak, bir laboratuar tipi evirici tasarlanmis ve sonuclar sunulmustur. Sistemin simulasyonu, Matlab Simulink kullanilarak yapilmistir.

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Hibrid Güç Sistemleri İçin Evirici Tasarımı

A closed-loop high-conversion-ratio switched- capacitor (HCRSC) boost DC-AC inverter is proposed based on sinusoidal-pulse-width-modulation (SPWM) control to achieve step-up DC-AC inversion and regulation. The power stage of the inverter is composed of HCRSC DC-DC booster and H-bridge DC-AC inverter connected in series between source Vs and output Vo. In the HCRSC booster, there are 4 SC capacitor cells with the interleaved and complementary operations in order to provide the 3x3 voltage gain at most. In the H-bridge, there are 4 MOSFETs included for the voltage- mode inversion, and by combining SPWM control, it is required that output Vo is following the reference Vref. This compensation is used not only to enhance the regulation to various outputs or source disturbance, but also to make the design of output filter easier for the better total harmonic distortion (THD). Here, the HCRSC boost DC-AC inverter is simulated by OrCAD, and the results are illustrated to show the efficacy of the proposed scheme. Index Terms—high-conversion-ratio; switched-capacitor; boost DC-AC inverter; sinusoidal-pulse-width-modulation.

http://www.iaeng.org/publication/IMECS2010/IMECS2010_pp1321-1326.pdf

Ming-Zong Wu

Papers

High-Conversion-Ratio Switched-Capacitor Boost DC-AC Inverter Using Sinusoidal PWM Control