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Due to demand increasing, most of power networks operate close to their stability limits. The high demand and the reduction of non-renewable energy sources impose the insertion of renewable energy sources. Their non-supervised insertion can cause voltage instability. In order to avoid this instability, a coordinated secondary voltage control system (CSVC) should be implemented. This paper describes the proposed procedure of CSVC system implementation. It is composed by three steps. The first step is the power network partitioning based on Self Organizing Map algorithm, the second one is the pilot buses selection based on the reduced Jacobian matrix and on voltage security performance index, and the third one is the CSVC system implementation based on the hybrid control approach using generators and shunt elements. These three steps are described in details in this paper. This procedure is used to maintain the voltage stability of large network. In this paper its efficiency is validated for small network also. Therefore it is implemented on the IEEE 39 bus system.

A new single-phase power factor corrector (PFC) based on the Sheppard-Taylor topology is studied. Compared with conventional PFCs, this topology facilitates a better input current tracking, lower voltage stresses across the devices and larger output voltage range for the same operating area. The converter is integrated as a PFC at the DC-end of a single-phase diode bridge. Pulse-width-modulated (PWM) multi-loops control schemes are proposed and developed in order to ensure a unity power factor at the AC-source side and a regulated voltage at the DC-load side. The first control method uses the simple and robust hysteretic-based controller; the second employs a conventional PI regulator; and the third is based on the model nonlinearity compensation approach. The design of the last two control methods is based on the knowledge of a mathematical model that would accurately represent the converter. This model is developed in this paper using the state-space averaging technique, and then the small-signal transfer functions of the converter are derived for linear control design purpose. The performance of the different control strategies is evaluated through simulation experiments carried out on a numerical version of the converter. The implemented model of the converter is obtained by using the switching function technique. The control system is tested under both rated and disturbed operating conditions. The system performance is evaluated in terms of source current total harmonic distortion (THD), input power factor, DC voltage stabilization, and regulation following load variations.

Recently, sparse matrix converters are gaining the researchers' attention as an improved alternative to traditional matrix converters thanks to the advantages they offer by reducing their number of semi-conductor switches. Three major solutions are found in the scientific literature to increase the voltage transfer ratio limited so far to 0.86; the reverse operation of the matrix converter, the over-modulation of the matrix converter and the introduction of a Z-source network in the dc stage of the converter. In this paper, the Very Sparse Matrix Converter (VSMC) is adopted since it presents the smaller number of switches in the family of bidirectional matrix converters. It is simulated in three configurations designated to increase the voltage transfer ratio while improving the overall performances of the converter in order to facilitate its implementation in the wind conversion systems. First, the VSMC is simulated in normal operation, then in reverse operation. Second, it is simulated with the cascaded Z-source network and finally with the series Z-source network. All four configurations are compared in terms of voltage transfer ratio improvement and output voltages and currents waveforms. Then, further analysis is carried out for the cascaded and series Z-source configurations in order to compare both arrangements. The series Z-source VSMC presents better performances in terms of output current THD and Z-source components reduced constraints.

Penetration of electrical sources based on renewable energies is becoming more and more significant in power transportation and distribution. Changes caused by this integration have an important impact on the network stability. This instability is avoided through the three hierarchical voltage control levels. In this paper we focus on the selection of pilot buses for the secondary level voltage control. Pilot buses are those where regulators are installed and the objective is to find the most appropriate selection that minimizes their number and maximizes the stability performance. A comparison between all existing selection algorithms is performed then an improvement is made on the most performing one. Results are validated by doing simulations on the standard IEEE 118 bus.

This paper presents a review of modulation and control strategies for matrix converters applied to permanent magnet synchronous generator (PMSG) in wind power generation systems. Modulation techniques already discussed in scientific literature for the command of matrix converters are mostly divided into three categories: the scalar modulations, the pulse width modulations and the predictive control modulations. These modulation methods are combined with maximum power point tracking (MPPT)-based control strategies to secure and improve the performance of the overall system. Control strategies are combinations of two elementary blocs: the MPPT algorithms and the regulation approach. MPPT algorithms are crucial for the improvement of wind harvest and regulation approaches are generally based on adaptive, non-linear or linear automatic methods that are responsible for current control or field oriented control or reactive power control.

This paper presents a review of the recent advances in matrix converter topologies used with the permanent magnet synchronous generator (PMSG) in wind power generation systems. Dedicated literatures introduce different topologies inspired by the conventional matrix converter. Two-stage matrix converters known as sparse matrix converters are compared to the conventional matrix converter in terms of implementation complexity, cost, power rating and voltage ratio. Single-phase matrix converters topologies are implemented in high power wind applications in two different modular concepts: the reduced matrix concept for offshore wind farms and the multi-modular high power matrix converter. On the other hand, several modulation techniques applied to the matrix converter-PMSG scheme are briefly presented.

This paper presents a classification for partitioning algorithms used in secondary voltage control of distribution power networks. Also it presents a comparative study on fifteen different algorithms based on structure dependence, initial conditions, input data types, zones isolation, repeatability, generators distribution, computation effort and fitness score. This wide comparative study has shown that Self Organizing Map algorithm is the closest to the ideal case.

Landmines are stilled scattered even today in many countries affected by wars. Conventional detection approaches are not optimized because the staff involved in this process although skilled and experimented, requires a long time for a safe and for an efficient detection that uses costly and accurate equipments. Therefore, some research are actually focusing on using wireless sensors networks for this purpose hoping that faster, safer, more accurate and more cost-effective methods will be found. Within this context, this work considers a network made of wireless biosensors randomly spread over the landmines field. It presents a comparative study on the energy consumption when different scenarios of data transfer are adopted. Simulation results are obtained in order to help in finding the optimal solution where the minimum data is lost, the minimum energy is consumed and the minimum redundant data is collected.

Capacitor banks are used to compensate the reactive power demand of large commercial and industrial loads. When used to switch capacitor banks mechanical breakers generate large current transients. These transients may cause serious system disturbances, premature wear of the breaker contacts and, possibly, shorten the life of the capacitors. While thyristor switches are not new and industry has successfully used them to obtain transient-free switching of capacitor banks, there are very few papers describing this application. This paper tries to fill the void and presents a comparative study of various three-phase configurations of semiconductor switches intended for low voltage (600 V and less) distribution systems. Simple theoretical analysis enables the calculation of the optimal switching times to minimize transients. These calculations take into account the system impedance and the initial capacitor voltages. >

In this study, a two-stage DC-DC converter for high current applications is studied. The converter consists of two three-phase full-bridge inverters connected through three AC coupled inductors. A switching-functions-based model of the converter is first established, and then a control scheme is designed for both inverters in order to ensure a high power factor at the AC stage, and a regulated voltage at the DC load. The performance of the proposed control system is verified through numerical simulations. First, an ideal DC source is considered in order to test the performance of the control system, then a proton exchange membrane fuel cell is applied as the DC source in order to highlight the usefulness of this converter in such applications.

Power electronics building blocks (PEBBs)-based design methodology uses off the shelves components and improves scalability and modularity. These PEBB design's approaches need to be unified, approved and standardised. To reach these objectives, most of the research efforts are currently focusing on suggesting a universal control scheme. In fact, the control strategies presented up to date and their methods for generating signals to control power electronic switches are still customised and depend on the control algorithm or on the application. To overcome this issue, a universal strategy is suggested for a universal control protocol for PEBBs. It links the hardware layer to the application layer of the control function and it highly promotes interoperability. Additionally, the suggested interoperable method generates the appropriate control pulses for a wide range of application independently from the control algorithms.