Active filtering of electric power has now become a mature technology for harmonic and reactive power compensation in two-wire (single phase), three-wire (three phase without neutral), and four-wire (three phase with neutral) AC power networks with nonlinear loads. This paper presents a comprehensive review of active filter (AF) configurations, control strategies, selection of components, other related economic and technical considerations, and their selection for specific applications. It is aimed at providing a broad perspective on the status of AF technology to researchers and application engineers dealing with power quality issues. A list of more than 200 research publications on the subject is also appended for a quick reference.

A review of active filters for power quality improvement

http://ieeexplore.ieee.org/iel5/5610941/5624686/05624745.pdf

Power electronics

This paper presents an optimal power management mechanism for grid connected photovoltaic (PV) systems with storage. The objective is to help intensive penetration of PV production into the grid by proposing peak shaving service at the lowest cost. The structure of a power supervisor based on an optimal predictive power scheduling algorithm is proposed. Optimization is performed using Dynamic Programming and is compared with a simple ruled-based management. The particularity of this study remains first in the consideration of batteries ageing into the optimization process and second in the “day-ahead” approach of power management. Simulations and real conditions application are carried out over one exemplary day. In simulation, it points out that peak shaving is realized with the minimal cost, but especially that power fluctuations on the grid are reduced which matches with the initial objective of helping PV penetration into the grid. In real conditions, efficiency of the predictive schedule depends on accuracy of the forecasts, which leads to future works about optimal reactive power management.

Optimal Power Flow Management for Grid Connected PV Systems With Batteries

With the fast-paced changing technologies in the power industry, new power references addressing new technologies are coming to the market. So there is an urgent need to keep track of international experiences and activities taking place in the field of modern unit-commitment (UC) problem. This paper gives a bibliographical survey, mathematical formulations, and general backgrounds of research and developments in the field of UC problem for past 35 years based on more than 150 published articles. The collected literature has been divided into many sections, so that new researchers do not face any difficulty in carrying out research in the area of next-generation UC problem under both the regulated and deregulated power industry.

Unit commitment-a bibliographical survey

The hydrogen-fueled internal combustion engine : a technical review.

This work investigates an actual violent failure of a number of variable frequency drives that were supplied by an ungrounded power source. It was noted that when a phase-to-ground fault was manifested in one of the motors, all the VFDs were destroyed except the one that is connected to the motor where the fault occurs. Circuit analysis and simulations using PSpice was carried out in an effort to explain the cause of such destruction. It is found that the inverters used in this facility were not designed for ungrounded power supplies, and the cause of such failure is the presence of an EMI capacitor filter that is placed between the DC link midpoint and ground.

Failure mechanism of variable frequency drives in ungrounded distribution systems

This paper describes the conversion of a lightweight pure electric vehicle into a hybrid fuel cell-battery vehicle. Integration of the two power sources, including the installation of a DC-DC converter for regulating the desired operating voltage and controlling the power supplied by the fuel cell, is presented in sufficient detail. The desired performance of the modified vehicle - that is where the fuel cell provides relatively steady power while the battery bank provides peak power - is illustrated by field measurements under different operating conditions

Light-weight fuel cell-battery hybrid vehicle demonstration project

This paper describes waveform distortion in power transmission lines equipped with thyristor-controlled series compensators (TCSC). Analytical expressions of currents and voltages are derived in terms of firing angle, line inductance and compensator circuit parameters. The analysis is illustrated by a numerical example which shows that line current distortion is very small (in the 1% range) for moderate levels of line compensation.

http://ieeexplore.ieee.org/iel4/6146/16439/00759964.pdf

Waveform analysis in thyristor-controlled series compensated transmission lines

A steady-state circuit model, based on that of a three-winding transformer, is used to represent the motor configuration designed by G.D. Roberts (1989). The model was found to predict the motor performance with remarkable accuracy. Optimal capacitor values that maximize the efficiency of both the Roberts motor and that proposed by C.L. Wanlass (1980) were determined for various load conditions. It was found that the Roberts motor under test is less efficient than the standard induction motor even when using optimal capacitor sizes at each load point. However, simulation results indicated that the Wanlass motor is slightly more efficient under heavy loads but less efficient under light loads, when compared to the conventional motor. >

Efficiency of dual-winding induction motors with integral capacitors

This paper investigates the effective capacity of grid-tied PV systems of different geometries on the local power grid. This statistical measure is derived experimentally from hourly system demand and power produced by two types of PV system configurations (a fixed array with 35 deg. south tilt, an a two-axis tracking system). Both the overall effective capacity over the study period and effective capacity associated with the peak load hours a derived. PV grid-penetrations ranging from 1% to 15% of utility peak have been considered.

Yahia Baghzouz

Papers

Failure mechanism of variable frequency drives in ungrounded distribution systems

Light-weight fuel cell-battery hybrid vehicle demonstration project

Waveform analysis in thyristor-controlled series compensated transmission lines

Efficiency of dual-winding induction motors with integral capacitors

Determination of photovoltaic effective capacity on local power grid