M.A. Eldery

A novel power quality monitoring allocation algorithm

Summary form only given. Distributed measurement architecture, due to its efficiency, is used to monitor the power quality in the electric systems. This paper introduces a novel algorithm to determine the optimum allocations of power quality monitors to reduce the cost of the distributed monitoring system taking into account the data redundancy. The optimization problem is formulated as a covering and packing one which can be manipulated by integer linear programming algorithms. The appropriate constraints are deduced by the electrical circuit topology independent of the load parameters. In addition, the problem is adopted to a general form which can be implemented by any optimization package. The proposed algorithm is applied to five different systems for validation. Then, the results are discussed in terms of the cost and data redundancy

Sliding Mode Controller For Pulse Width Modulation Based DSTATCOM

In this paper, a controller is designed to achieve robust control for DSTATCOM which is controlled as a voltage source inverter utilizing pulse width modulation. DSTATCOM dynamic equations show that the nonlinearities of the DSTAT COM and uncertainties of the system model have large contribution in system dynamic response. Hence, a robust nonlinear control strategy based on sliding mode control, which is a standard approach to tackle the parametric and modeling uncertainties of a nonlinear system, is chosen for the control. For sliding mode controller, Lyaponov stability method is applied to keep the nonlinear system under control. The sliding mode approach is a method which transforms a higher-order system into first-order system. In that way, a simple control algorithm can be applied, this is very straightforward and robust. The simulation results show the ability of the proposed controller to give an enhanced performance at all operating points and with different load types

Identification of partial discharge locations in transformer winding using PSD estimation

This letter presents a new technique to identify partial discharge locations in transformer winding using electrical measurements. Useful features, which pinpoint the locations of partial discharges, are extracted from the periodogram of the secondary voltage of the transformer. These features are manipulated by a distance classifier to determine the locations of the partial discharges. Simulation results proof that the proposed method is efficient and can handle effectively transformer parameters deviations due to aging.

A simple energy operator computational method for voltage flicker assessment

In this paper, a novel algorithm, based on calculating the energy operator of a sinusoidal waveform to track the voltage flicker, is presented. The mathematical derivation of the proposed algorithm different circuit designs required to realize it are described. The proposed algorithm is fast and robust and requires only a few samples to calculate the energy. The simulation and the experimental results prove that the new algorithm can successfully track the envelope. There are no spikes in the envelope even when the voltage signal is suddenly changed at its peak value.

DSTATCOM Effect on the Adjustable Speed Drive Stability Boundaries

In this paper, the dynamic models for adjustable speed drive (ASD) and distribution-static compensator (DSTATCOM) are presented. An eigen domain approach to the transient response investigation is formulated by means of dqo variable in synchronously rotating reference frame to study the dynamic interactions between ASDs and DSTATCOM. Two inverter topologies of ASD, current source inverter and voltage source inverter, are included in the study as well as two control techniques of the DSTATCOM, namely voltage and current control. The study shows that the voltage control DSTATCOM improves the stability boundaries of the ASD utilizing either current or voltage source inverters, while the current control DSTATCOM has minor influence. In addition, the system dynamics show less sensitivity to the dc link capacitance for the voltage control DSTATCOM. These results are supported by analytical study of the characteristic equation of both the voltage and the current control DSTATCOM

A novel energy operator algorithm for voltage envelope tracking

A novel algorithm for tracking the voltage envelope based on calculating the energy operator of a sinusoidal waveform is presented. Like other energy operator algorithms, the algorithm is fast and robust and uses only a few samples to calculate the energy. Unlike the existing algorithms, the proposed algorithm is not sensitive to the noise or the distortion in the waveform. The mathematical derivation of the continuous form is presented, and a simple discrete form is then deduced. The simulations show the capability of the algorithm to track different shapes of envelopes associated with high signal-to-noise ratio (SNR).

Effect of distributed generator on the allocation D-STATCOM in distribution network

This paper studies the D-STATCOM allocation problem to mitigate the voltage fluctuation on the distribution system and the effect of the distributed generation on the proper location and the economical size. The mathematical formulation of the problem is presented. The loads and D-STATCOM are modeled by their equivalent current sources. The power electronic based distributed generators are used to mitigate the voltage fluctuation, therefore the effect of those distributed generators on the allocation problem are studied as well.

A virtual instrument for voltage flicker tracking

In this paper a virtual instrument for voltage flicker is introduced. The proposed instrument utilizes Hilbert transform (HT) and Teager energy operator (TEO) for tracking the voltage signal envelope. A test system, which is capable of producing flicker with different frequencies and amplitudes, is designed to test the proposed flicker tracking system. An economical data acquisition card is used to capture the flicker voltage waveform. The tracking algorithms are implemented using Matlab6.0. Experimental results presented in this paper prove the competence of the anticipated instrument.

An on-line measurement of symmetrical components utilizing the energy operator

This paper introduces a new methodology for instantaneous measurement of symmetrical components utilizing the energy operator concept. The energy operator is used to measure the changes in the amplitudes and the angles of the three phases which are then processed to calculate the symmetrical components. The proposed technique is robust, fast, simple, stable and easy to implement. Various signals experienced with different power quality problems are used to test the proposed algorithm. The results prove the efficiency of the proposed technique

Parameters identification of sectional winding high frequency transformer model using neural network

In this paper, the parameters of the power transformer model are identified to simulate its behavior under high frequency transients. The mathematical description of the sectionalized model of the transformer using two-port network topology is given. The adoption of the neural network to estimate the parameters of the sectionalized model is presented. The proposed estimation method overcomes the assumption of identical sections. The results show the ability of the proposed method to estimate the parameters with less sensitivity to the initial guess of the parameters.