Power
Mohammad Abedini; Mahyar Abasi
Abstract
Maintaining power system stability can be challenging due to low-frequency fluctuations. Traditionally, power system stabilizers (PSS) and unified power flow controllers (UPFC) have been used to address this issue. This paper proposes a novel approach that leverages both PSS and UPFC simultaneously, ...
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Maintaining power system stability can be challenging due to low-frequency fluctuations. Traditionally, power system stabilizers (PSS) and unified power flow controllers (UPFC) have been used to address this issue. This paper proposes a novel approach that leverages both PSS and UPFC simultaneously, controlled by an optimized fuzzy logic system. The proposed fuzzy controller aims to enhance the efficiency of both PSS and UPFC, ultimately boosting system damping. The controller takes two key inputs: changes in angular speed and power angle. To dynamically adjust its response to changing system conditions, a shuffled frog leaping algorithm optimizes the fuzzy controller's gains. To assess the effectiveness of the controller, simulations are conducted across three different loading levels for the studied system. The results are presented for each stage and demonstrate a significant reduction in overshoot and improved overall system damping. Our method achieves a remarkable 43% enhancement in damping compared to PSS, a 45% improvement over UPFC alone, and a staggering 48% advantage over the hybrid PSS-UPFC approach.
Electronics
Alireza Khoshsaadat; Mohammad Abedini
Abstract
In this paper a new improved diode-based circuit is introduced for output voltage limiting of immittance-based constant current Load Resonant Converters (LRCs). The proposed Diode-based Voltage-Limiter (DVL) is very reliable and simple, and also has minimum number of components. Moreover, limiting values ...
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In this paper a new improved diode-based circuit is introduced for output voltage limiting of immittance-based constant current Load Resonant Converters (LRCs). The proposed Diode-based Voltage-Limiter (DVL) is very reliable and simple, and also has minimum number of components. Moreover, limiting values are flexible and can be varied according to the design requirements. All of the positive characteristics of the LRC operation are preserved in this technique such as Zero Voltage Switching (ZVS) of the inverter switches and Zero Current Switching (ZCS) of the rectifier diodes. A 150W converter with 300kHz switching frequency is considered as a sample prototype. The circuit simulation is presented based on the real model of the semiconductor devices in the OrCAD environments to have maximum accordance with the real conditions. Simulation results demonstrate an accurate clamping ability of the output voltage for overload conditions without any characteristics variation.