International Journal of Applied Power Engineering (IJAPE)
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Increasing performance of chiller systems in high-rise buildings by load optimization
Get PDFRecently, the construction of high-rise buildings has been increasing significantly along with economic growth. Therefore, electricity is also going up due to the energy demand of the building. The air conditioning system is the enormous energy consumption in high buildings. The green building concept has been introduced regarding the energy efficiency of a high-rise building. This study investigated the energy consumption in a high building (47 floors) using the load optimization method for the chiller system. The load optimization was conducted by configuring five chillers systems consisting of integral compressors, cooling towers, and pumps. This study obtained the decreasing energy consumption by the chiller's operation load sequencing based on 24-hour data optimization. Optimized chiller performance satisfied the green building standards. However, load optimization on high buildings is highly recommended as an effective way to achieve green building status. Further research is recommended for implementing such optimization at other facilities, such as industrial plants, hospitals, airports, and manufacturing plants
Evaluating a novel bidirectional soft-switching DC-DC converter for electric vehicles
Get PDFThis research aims to build unique zero voltage transition (ZVT) non-isolated bidirectional DC-DC converters for hybrid electric vehicle battery storage. First, a high-voltage gain bidirectional converter (BDC) is examined. This converter can soft-switch insulated gate bipolar transistors (IGBTs). The primary insulated-gate bipolar transistors (IGBTs) are operated under zero-current conditions throughout the turn-on to turn-off commutation phase to reduce switching losses and increase efficiency. A soft-switched cell with a resonant inductor, capacitor, and additional IGBTs achieves zero-current turn-off. A new converter uses insulated-gate bipolar transistors with zero-voltage transition operation. Soft-switched cells improve the hard-switched bridgeless DC-DC converter (BDC). Resonant inductors, capacitors, and auxiliary switching devices make up the soft-switched cell. Soft-switched cells enable zero voltage turn-on of primary insulated-gate bipolar transistors. This converter charges the battery in buck mode and boosts it to provide the necessary output voltage. This study examined a 70 V/300 V power system's high-gain bidirectional converter (BDC) design simulation. The converter was tested at 50 kHz with 800 W output power. The high-gain soft-switched BDC has 96.5% boost and 97% buck efficiency. Operating principles, design analysis, and simulation assessments are included in this study
Improved convergence speed using hybrid AI for TD EM modeling in power electronics
Get PDFThis paper presents a time-domain (TD) approach based on hybrid artificial intelligence (AI) to speed up convergence of radiating sources characterization in power electronics. To obtain a representative equivalent model of device under test, a dedicated optimization framework has been developed in TD using a particle swarm optimization (PSO) toolbox. In addition, for elementary feature extraction, a pseudo-Zernike moment invariant (PZMI) descriptor has been defined. Finally, with the aim of identifying remaining dipole parameters and classification problems, artificial neural networks (ANN) have been implemented. A coupling of TD electromagnetic (EM) inverse method based on a PSO algorithm along with PZMI and ANN application has been investigated and applied to a real test case. Experimental measurements have been conducted using the near-field scanning technique above an alternating current (AC)/direct current (DC) converter. Obtained results are discussed based on a comparison between measured and estimated EM field distributions using both the hybrid AI method and a conventional TD inverse method based on genetic algorithms (GA) only. This study confirms that, compared with those given by non-hybrid method, the proposed algorithm further improves the convergence speed while maintaining high accuracy. Hence, the present work offers an impressive perspective for radiated emissions characterization using hybrid AI algorithms
A new optimal space vector modulation with DTC switching strategy for induction motor control
Get PDFEfforts to achieve swift and precise dynamic torque control have been central in AC drive research. Recent advancements in embedded computer systems have highlighted direct torque control (DTC) and field-oriented control (FOC) as key methods for enhancing torque dynamics, both utilizing space vector modulation (SVM) to optimize voltage source inverter positioning. This study introduces a novel synthesis by integrating DTC with SVM to address limitations in conventional DTC, which suffers from limited voltage vector availability, leading to undesirable torque behavior and significant current fluctuations. The primary goal is to develop an optimal switching modulator for the fastest torque response through the combined application of DTC and SVM. The proposed strategy optimizes DC bus usage, reduces torque fluctuations, minimizes total harmonic distortion in AC motor current, decreases switching losses, and ensures seamless digital system integration. Simulations using MATLAB/SIMULINK demonstrate significant torque, current, and flux linkage ripple reductions, validating the approach's effectiveness. This integration overcomes established limitations, extending the capabilities of motor control methodologies and offering enhanced performance and operational integrity in induction motor drive systems
Analysis of single switch step up DC-DC converter with switched inductor-switched capacitor cells for PV system
Get PDFThe presented work exhibits high gain and increased efficiency for DC-DC converter. Additionally, this topology significantly improves the voltage conversion ratio when compared with other DC-DC converters reported recently. The non-existence of high frequency transformer ensures compactness and low cost and henceforth, it is apt for clean energy applications. The analysis of the high gain converter in steady state is carried out in continuous conduction mode (CCM). Initially, the proposed converter performance is analyzed using MATLAB/Simulink platform and prototype of the same with a power rating of 200 V, 100 W is built and tested. The reliability and robustness of the converter is perceived from the experimental results and peak efficiency achieved is around 93%
Optimized control strategy for a three-phase grid connected inverter using PI controller and DQ frame
Get PDFThis paper provides a proportional-integral (PI) controller and direct-quadrature (DQ) frame transformation-based optimum control method for a three-phase grid-connected inverter. In terms of grid synchronization, voltage regulation, and harmonic abatement, the proposed control technique attempts to improve the inverter's performance. By separating the control of active and reactive power, the control structure is made simpler and independent regulation of these parameters is possible. This improves the inverter's capacity to quickly react to grid disruptions and track reference values accurately. In order to lower carbon emissions and improve grid dependability, it has become vital to integrate renewable energy sources into the current power grid. Grid-connected inverters are essential in this situation because they transform DC electricity from renewable sources into grid-safe AC power. This abstract outline a proportional-integral (PI) controller and direct-quadrature (DQ) frame-based optimal control method for a three-phase grid-connected inverter using a MATLAB simulation
A novel SIMIDCBC topology driven PMSM for PEV application
Get PDFNowadays, the usage of renewable energy based electric vehicles is increased for reducing CO2 emissions, usage of fossil fuels, energy saving, and transportation cost. As a result, it becomes the most significantly run with combined energy sources and it is good choice which minimizes the energy consumption from charging stations. The available renewable energy is integrated to power-train through power-electronic interface; such interface consists of three-phase inverter with DC-DC boost converter. The combined energy sources like solar-PV/battery are integrated to power-train by employing multi-input non-isolated step-up DC-DC converter for providing continuous power to drive the vehicle. The multi-terminal topologies have efficient, reliable performance, continuous input current, high step-up gain over the conventional DC-DC converters. In this work, a unique framework of combined energy powered switched-inductor based multi-input DC boost converter topology has been proposed to drive the PMSM. The performance of proposed SIMIDCBC topology driven PMSM for PEV application under constant and variable speed conditions are verified by using MATLAB/Simulink tool, simulation results are presented
Three-phase model of SCIG-based variable speed wind turbine for unbalanced DSLF analysis
Get PDFSteady state performances of the electric power distribution system are normally assessed or evaluated based on load flow analysis. To properly carry out the analysis, a valid steady state load flow model of each distribution system component, including the wind power plant (WPP), needs to be developed. The present paper proposes a method for modeling and integrating squirrel cage induction generator (SCIG)-based variable speed WPP into a three-phase unbalanced distribution system load flow (DSLF) analysis. The proposed method is based on a single-phase T-circuit model of fixed speed WPP, which has successfully been applied to balanced electric power systems. In the present work, the single-phase T-circuit model is extended and modified to be used in steady state load flow analysis of three-phase unbalanced distribution systems embedded with SCIG-based variable speed WPP. Results of the case studies confirm the validity of the proposed method
Short-circuit current analysis of DC distribution system in a ship with non-electric propulsion
Get PDFConverting conventional AC radial shipboard distribution system to DC system has been recognized as a potential high impact solution to reduce ship’s fuel consumption. As big ships in Indonesia commonly use low voltage AC (LVAC) distribution system an effort to apply low voltage direct current (LVDC) distribution system without replace the propulsion system is a plausible choice. However, technical and economical investigations are required before recommendation to convert the shipboard distribution system to LVDC is officially launched. In this study, technical aspect in the term of short-circuit current is discussed. The goal of this study is to analyze how much the impact on the short-circuit current when LVDC system replaces LVAC system. The impact may affect the feasibility of LVDC system as the short-circuit current in a system dictate the scheme and capacity of the protection devices. Numerical simulations on a sample vessel are performed to obtain the profile of maximum short-circuit currents on all panels. The results show that the utilization of LVDC system decreases the short-circuit current by 10 times. Further investigations on the economic aspect needs to be performed to give clearer view of the feasibility of the LVDC system
Optimal feeder routing and phase balancing for an unbalanced distribution system: a case study in Cambodia
Get PDFThis paper aims to minimize the distance of the feeder path from high-voltage/medium-voltage (HV/MV) substation to medium-voltage/low-voltage (MV/LV) transformers and minimize power loss in an unbalanced distribution system by the phase-swapping concept-based load balancing. The shortest path algorithm (SPA) and the genetic algorithm (GA) for optimal feeder routing and phase balancing separately in the MV unbalanced distribution network are proposed. First, the relevant data for the system is collected. These data include substation coordinates (X, Y), active and reactive power (P, Q), phase connections, and lines’ impedance (Z). secondly, the performance of the existing configuration of the test system with numerous indications is presented. Finally, the proposed method is performed to minimize the length and power losses. The real 47-bus test system in Cambodia is chosen to demonstrate the proposed method. In this study, overall power losses, the maximum voltage imbalance, and voltage regulation are computed by the backward/forward sweep load flow. The results based on the simulation indicate the importance of the proposed approach, especially for distribution system designers and operators