Showing 4 results for Dehghan
S. M. Dehghan, A. Yazdian, M. Mohamadian,
Volume 2, Issue 2 (April 2006)
Abstract
In this paper a hybrid active DC line conditioner for fluctuations and ripples
reduction in voltage and current of DC power systems is proposed. Malfunctions in
operation of equipments and systems which are supplied by low quality distribution power
systems are one of the main effects of DC voltage ripple. In the proposed configuration a
hybrid system including series and shunt active line conditioners for ripple reduction of
load voltage and source current is used. Simulation and experimental results are provided to
show the performance of the proposed configuration in different states.
S. M. Dehghan, M. Mohamadian, A. Yazdian, A. H. Rajaei, Mr H. Zahedi,
Volume 6, Issue 4 (December 2010)
Abstract
This paper presents a modified nine switch inverter with two inputs and two Z-source networks. This inverter has two DC inputs and two AC outputs. Input DC voltages can be boosted to the required level. Amplitude, frequency and phase of AC output voltages can be controlled, independently. The proposed converter can be used in applications with two unregulated DC sources, which require feeding two independent loads. Compared to the conventional structure, the proposed converter requires reduced number of semiconductor switches hence improved converter reliability and less volume. Performance of the proposed inverter is verified by experimental results.
Z. Gallehdari, M. Dehghani, S. K. Nikravesh,
Volume 10, Issue 2 (June 2014)
Abstract
The purpose of this paper is to present a new approach based on the Least Squares Error method for estimating the unknown parameters of the nonlinear 3rd order synchronous generator model. The proposed method uses the mathematical relationships between the machine parameters and on-line input/output measurements to estimate the parameters of the nonlinear state space model. The field voltage is considered as the input and the rotor angle and the active power are considered as the generator outputs. In fact, the third order nonlinear state space model is converted to only two linear regression equations. Then, easy-implemented regression equations are used to estimate the unknown parameters of the nonlinear model.
The suggested approach is evaluated for a sample synchronous machine model. Estimated parameters are tested for different inputs at different operating conditions. The effect of noise is also considered in this study. Simulation results show that the proposed approach provides good accuracy for parameter estimation.
H. Zayyani, M. Dehghan,
Volume 11, Issue 1 (March 2015)
Abstract
This paper presents a simple and easy implementable Least Mean Square (LMS) type approach for frequency estimation of three phase power system in an unbalanced condition. The proposed LMS type algorithm is based on a second order recursion for the complex voltage derived from Clarke's transformation which is proved in the paper. The proposed algorithm is real adaptive filter with real parameter (not complex) which can be efficiently implemented by DSP. In unbalanced situations, simulation experiments show the advantages and drawbacks of the proposed algorithm in comparison to Complex LMS (CLMS) and Augmented Complex LMS (ACLMS) methods
