Sergio Daher was born in Fortaleza-Brazil on the 3rd of August 1971; son of Elias Daher and Josephina Sophia Lira Daher. Since young, he showed interest in sciences and latter he gave special attention to the electrical and electronic engineering areas, what remains until today. His main areas of interest are: Power Electronics, Renewable Energy […]

( MATLAB 5.3.0.620a (R11) – Student Edition ) % Experimental data used (Efficiency x power) % File: n48v. mat %|- – Experimental……… % Pout Efficiency[%] % 60 76.27 % 120 86.36 % 238 92.3 % 297 93.52 % 355 94.31 % 449 95.08 % 561 95.59 % 673 95.84 % 783 95.95 % 945 96 […]

The implemented prototype is protected against over-current conditions at its input and output by using the circuits shown in figures (a) and (b), respectively. The input protection circuit makes use of the battery current sensor. It simply compares the sensor output with an adjustable voltage reference and generates a pulse that is applied to both […]

Schematic of main controller Ib_ad ЛЛЛ/—° (Battery Current) 22R 4v7 Vb ad WV—о ( Battery Voltage) 22R 4v7 Vo ad ЛЛЛ,—0 (Output Voltage) 22R   і Vc+o   From measurement circuits   ■WV—oTemp_ad22R (Temperature Sensor)   лл/v—° Ip_ad 22R (Trans. Current) 4v7   to auxiliar microcontroller   From protections circuits О ISc   О OSc […]

1. General information The Multilevel waveform design tool was developed in C language, using Builder 1.0 (for Windows) visual programming environment. All sources are available from the author ( sdaher@secrel. com. br / daher@re. e-technik. uni-kassel. de ). Main features are: – Construction of multilevel waveforms up to 35 levels per quarter cycle, with the […]

(Estimated normalized currents at the transformer coils and output stage switches) Output current: Ios = 1.0 Input current: Ip Peak transformer ratio: ^pk = 1.0 In : current thought the nth output stage switch. Note that transformer secondary currents are equal to the correspondent series-switch current (odd switch). p__ Ip I1 I2 I3 I4 I5 […]

There are several interesting topics for further research: ■ The implemented controller does not take into account that the inverter output voltage can present a DC-level if the inverter feeds unsymmetrical loads, such as half-wave loads. Future implementations must include a mechanism to monitor and eliminate any possible output voltage DC-level. ■ The implemented controller […]

This dissertation had investigated a high efficiency multilevel inverter topology which has great potential for application in stand-alone renewable energy systems. The presented study was focused on small systems (< 10 kWp) and it was showed that most typical system configurations store energy in battery banks in order to overcome the intermittence and peak power […]