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A hybrid magnetic approach, merging two different magnetic core properties such as ferrite and iron powder cores, is an effective solution for power converter applications. It can offer similar magnetic properties to that of magnetic powder cores but showing less copper loss than powder cores. In order to prevent ferrite core saturation, placing an effective air gap within the ferrite core is a key...
Owing to its advantages over the series resonant inverter particularly in the high power applications, a focus is made in this paper on the design and development of parallel resonant inverter for induction metal hardening. Performances investigation is made to highlight its features in term of power control using various techniques. Digital simulation is developed using CAD techniques and finally...
In general, the distributed generation (DG) inverters can operate in parallel in islanded microgrids through droop characteristic based control technique. This control technique is suitable for long distance DG inverters to achieve proper power sharing while ensuring good voltage regulation. On the other hand, the traditional droop control shows some disadvantages, such as the requirement for multi-loop...
To fully incarnate the characteristic of the high luminous efficacy of the low pressure sodium lamp (LPS) and to optimize the efficiency of the system which is made up of the LPS and the electronic ballast, a detailed research on the system has been done. Theoretically, the luminous efficacy of the LPS and the efficiency of the electronic ballast are both vary obviously with the work frequency of...
In recent years, Active Magnetic Bears (AMBs) becoming attractive for several reason such as frictionless rotation, high reliability and high speed operation. Moreover, AMBs are today an interesting alternative to standard bearing due to power electronics and control hardware price reduction, but the main disadvantage of AMBs is that they are design to have a small airgap and a high stiffness. This...
A Single Phase Dynamic Voltage Restorer (DVR) based on five-level ground point shifting multilevel inverter topology has been proposed in this paper. The proposed inverter has a floating ground point. Therefore, by shifting the ground point, it is observed that the inverter circuit gives five output voltage levels from single DC voltage source. This configuration uses less number of switches compared...
A novel scheme for the control of three-phase two-level grid-connected power converters is presented in this paper. A cascade-control structure, based on H∞ control and sliding mode control (SMC), is proposed, which simultaneously achieves output voltage regulation and unity power factor under dc-load variations. The overall control strategy contains two main loops: first, a current tracking loop...
In this article applications of solid state switches at medium- and high-voltage-level are presented. The switches have been developed to excite grid connection point with pulsed current signals in order to identify the frequency characteristic of the internal network impedance. Further on these switches can be used as switching nodes to change different grid structures as well as remote controlled...
Dynamic states in the power grid - deep voltage sags and swells, voltage fluctuation - can cause faults and defects in sensitive loads and in consequence financial losses. This paper presents the concept of a smart distribution transformer, without DC energy storage, to mitigate up to 50% voltage sag/swell and voltage fluctuation and protect sensitive loads against voltage perturbation. The presented...
A new multiphase resonant converter arrangement with series dual phase in the primary side and parallel dual current doubler in the secondary side, operating as a phase shift controlled current source is presented. Sharing the voltage and current stress among the active and passive components with a high DC input voltage and arc current motivates this structure, which also uses WBG devices to increase...
The high power density of Supercapacitors (SCs) make them good elements for Hybrid Energy Storage Systems (HESSs). In order to increase the amount of energy of their high power bursts, they should operate with large voltage variations. This paper presents the design equations of a 3-switch bidirectional DC-DC converter with a tapped inductor that can be used for interfacing SCs to DC buses. Some of...
Paper presents synthetic analyses of single input, dual output DC/AC/DC converter with common high frequency transformer. Rise the problem of cross-coupling power flows between secondary terminals, under asymmetrical control operating condition. It also proposes a new approach to converter control, based on conjugated phase shift modulation and defines its limitations. Finally, the developed control...
The paper describes graph-based approach, which allows introducing the process of electric energy transmission and distribution by means of directed energy flows and cost flows in a network equivalent circuit. The main idea deals with the allocation of electric utilities' energy transport costs between output nodes of an electric network. The methodology proposed can be characterized as two-stage...
The paper aims to realize the micro-grid control in presence of distributed generation (DG) sources and the automatic voltage regulators (AVR). The provided analysis had into account highlighting the influence of the hybrid energy systems with consideration of the automatic voltage regulators on the power losses and the voltage level into micro-grids. The obtained results with the highest power/energy...
This paper presents the load frequency control in isolated ac microgrid using fuzzy logic table control. The objective of load frequency control is to hold the frequency constant against any load changes. The main task of microgrid is to maintain the voltage level supply to the loads. Any mismatch between the power generations and loads create to the major problem of frequency fluctuation that effected...
The subsynchronous oscillation (SSO) phenomenon may occur in a modular multilevel converter-based high-voltage dc (MMC-HVDC) transmission system for wind farm integration, which has already been observed in the real world. In this paper, the generation mechanism of the SSO phenomenon in the interconnected system is revealed by means of impedance-based analysis. On this base, from the HVDC converter...
The paper focuses on the flexible management of the centrifugal pumps with variable speed drives primarily used for water circulation in closed processes, such as heating, cooling, and air conditioning. The goal of the study is to implement the mutual pressure and flow control, which provides the minimal electricity consumption along with the speed range enlargement. To resolve the problem, two methods...
Synchronous reluctance motor (SynRM) have rather poor power factor. This paper investigates possible methods to improve the power factor (pf) without impacting its torque density. The study found two possible aspects to improve the power factor with either refining rotor dimensions and followed by current control techniques. Although it is a non-linear mathematical field, it is analysed by analytical...
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