Sharif Digital Repository

In this paper, optimal control strategy is applied to parallel three-phase inverters using SVPWM technique. The three-phase system is transformed to a synchronous-stationary frame, suitable cost functions are defined, and the switching schemes are determined for the inverters. The control strategy minimizes the circulating current between the inverters, therefore, proper load sharing scheme is achieved. Simulations are performed for steady state and load change operation, and the results which show the suitability of the controller are provided. ©2009 IEEE  

A high energy-efficiency and low-area switching method is proposed for the successive approximation register analog-to-digital converters. In the proposed scheme, the threshold voltage for comparison is derived from the charge sharing technique and using a voltage source connected to the bottom plates of the digital-to-analogue converter (DAC) capacitors. The switching method achieves an average DAC switching energy and DAC area reduction of 99.15% and 84.27%, respectively, with respect to the conventional method. The differential nonlinearity and integral nonlinearity of the proposed scheme are 0.1288 LSB and 0.1207 LSB, respectively. In addition, in the proposed method, the number of DAC... 

A high energy-efficiency and low-area switching method is proposed for the successive approximation register analog-to-digital converters. In the proposed scheme, the threshold voltage for comparison is derived from the charge sharing technique and using a voltage source connected to the bottom plates of the digital-to-analogue converter (DAC) capacitors. The switching method achieves an average DAC switching energy and DAC area reduction of 99.15% and 84.27%, respectively, with respect to the conventional method. The differential nonlinearity and integral nonlinearity of the proposed scheme are 0.1288 LSB and 0.1207 LSB, respectively. In addition, in the proposed method, the number of DAC... 

Several attempts have been made to design suitable controllers for DC-DC converters. However, these designs suffer from model inaccuracy or their inability to desirably function in both continuous and discontinuous current modes. This paper presents a novel switching scheme based on hybrid modeling to control a buck converter using mixed logical dynamical (MLD) methodologies. The proposed method is capable of globally controlling the converter in both continuous and discontinuous current modes of operation by considering all constraints in the physical plant such as maximum inductor current and capacitor voltage limits. Different loads and input voltage disturbances are simulated in MATLAB... 

Developing efficient and appropriate modeling and control techniques for DC-DC converters is of major importance in power electronics area and has attracted much attention from automatic control theory. Since DC-DC converters have a complex hybrid nature, recently several techniques based on hybrid modeling and control have been introduced. These techniques have shown better results as compared with conventional averaging-based schemes with limited modeling and control abilities. But the current works in this field have not considered all possible dynamics of the converters in both continuous and discontinuous current modes (CCM, DCM) of operations. These dynamics are results of controlled...