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This paper presents a distributed control for dc microgrids that minimize the total generation cost and regulate the average voltage at the desired value. The proposed controller includes two modules; lower cost regulator and voltage regulator. In addition, a sparse communication network with a balanced laplacian matrix is used for data exchange between converters as each converter communicates only...
High capacity of direct current is essential in many industrial processes. Conventional methods for obtaining high amount of direct current involve parallel operation of converters with multi-pulse rectifier. The multi-phase transformer combined with rectifier in the system increases overall size of the system and also provide limited control over the operation. This paper presents simpler topology...
Recently, Model Predictive Controller (MPC) becomes the most attractive control in power electronics and drives applications. It is incorporated in Z-Source Inverter family (ZSI) where each of capacitor voltage, inductor current and output load currents could be controlled at their setting points' values. In this paper, a proposed algorithm for qSZI is introduced to simplify the system through reducing...
This paper discusses the common Line Powering standards for safety with their advantages and their drawbacks. It also discusses the effects of electrical shock and risk of ventricular fibrillation on humans and the two types of faults that can occur with RFT-V line powering. Based on the standards for the effects of current on human beings and livestock, two flowcharts are developed to help unify...
Today, electricity distribution and communication networks are getting more tightly integrated as smart grids evolve. From time to time, extreme weather conditions such as severe wind and snow storms cause large outages in electricity distribution networks in Northern countries. Loss of electricity can hinder remote control of grid entities and causes a chain-effect that jeopardizes energy generation,...
The comparison of the power stage dynamics between a conventional LLC converter and a three-level LLC converter is presented in this paper. The frequency response was similar in continuous current mode, but different in discontinuous current mode. Moreover, how the variation of circuit parameters affects the transfer function of the three-level LLC converter is studied. The experimental verification...
The European Commission is supporting many projects in the field of energy saving, with the aim to improve user behavior and to help Europe to meet emission targets. In October 2012, the European Union adopted the Energy Efficiency Directive with the aim to reduce the primary energy consumption by 20% by 2020. One key point in the reduction of energy consumption energy is the awareness of final users...
In a DC distribution system, the reliability of the interfacing converter is crucial. The ability to detect the fault occurrence in a fast and accurate manner for fault mitigation is one of the criteria for fault diagnosis of a distribution system in a built environment. In this paper, an interfacing cascaded boost chopper rectifier is used as a case study for fault diagnosis. Wavelet transform of...
For development of inductive coupled wireless power transfer (WPT) systems, it is important to consider the overall efficiency of the WPT systems, where the overall efficiency is expressed as the product of the transmission efficiency of coupling coils and the power-conversion efficiency of power converters. Additionally, there are mutual dependencies between coupling coil parameters and power-converter...
In recent years a growing attention is being paid towards energy efficiency in civil and industrial applications. In order to achieve better efficiency and enhance the energy management strategies, better knowledge is needed on the characterization of energy consumers. Categorization of electrical consumers through clustering procedures has been widely addressed in the literature. However, the categorization...
Supply of power is an increasing cost factor in the operation of base transceiver stations (BTS). Selecting the optimized power system for a set of site requirements is key to minimize total cost of ownership (TCO). In this paper we show how dimensioning of a power system through combined technical and commercial simulation helps to optimize the system configuration. The savings on fuel and diesel...
This paper proposes droop control for Multi-Level Virtual Conductor (MLVC). This control method aims at overcoming the problem that circulating current flows when MLVC constitutes a mesh connection. Generally, the voltage difference between the terminals of any conductor is zero volts. However, MLVC can keep the voltage difference between the converter terminals constant at a certain value. In this...
This paper proposes a new Space Vector PWM (SVPWM) method for reducing the neutral point potential variation of the three-level V-connection inverter. In the proposed method, by selecting the vectors which has low neutral point potential variation to generate the output voltage command value, the neutral point potential variation of the V-connection inverter can be reduced. In addition, the neutral...
This paper proposes a modified 4-phase interleaved converter for the FC power source for mobile based station applications. The ripple and harmonic content of the FC current is one of the various phenomena influencing FC lifetime. The main objective of this research is to minimize inductor size, capacitor, current/voltage ripples, and harmonic content. The main contribution is to presents a control...
Cylindrical large formatted lithium-ion-battery “CH75” cells, battery pack “CH75-6” for stationary use, energy storage systems utilizing the CH75-6 to be applied to industrial applications and these characteristic points are described. In particular, energy storage systems for frequency-regulation applications and the cooling design of the battery panel are described.
The purpose of this paper is to present the digital peak current mode phase-shifted full-bridge zero volt switching dc-dc converter for the data center in the higher voltage direct current (HVDC) system, and show its transient response. The proposed peak current mode control circuit is composed of the RC integrator and comparator only and can detect the peak current in real time. At first, the basic...
To promote the widespread use of HVDC power supply systems, this paper proposes high-efficiency downsized power conversion (380 V to −48 V) equipment for HVDC use having a size small enough for mounting in the dead space of a rack and describes its performance. Configuring 380 V/−48 V conversion equipment with existing technology lowers the efficiency of the entire power supply system and increases...
In this paper, a nanosecond level response digital pulse width modulation (PFM) control circuit for the current resonant converter such as LLC has been proposed. The proposed circuit is composed of a unique analog to digital converter and logic based digital controller. With the experimental results, it was confirmed that the switching frequency can be varied from 0.8 to 1.2MHz in regard to 20% variation...
This paper proposes a method to improve the power efficiency in the half-bridge LLC resonant DC-DC converter. The optimum design of a transformer is discussed to improve power efficiency. The interlinkage magnetic flux in the primary and secondary wires causes eddy currents, which results in a power loss. This study demonstrates that power loss can be reduced through optimum design of the strand diameter...
This paper focuses on the circuit which is to reduce the number of switching elements in comparison to a common multi-level inverter NPC inverter. Increasing the number of levels of the output voltage at reduced circuit number switching elements, and performs waveform improvement. Typically, the ratio of the input voltage of the multi-level inverter is E1 : E2 = 1 : 1. When the ratio of the input...
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