Power loss models for the portable phone "Pointel" in a typical indoor environment

The flyback converter has been widely used in Photovoltaic microinverters, operating either in Discontinuous, Boundary, or Continuous Conduction Mode (DCM, BCM, CCM). The recently proposed hybrid DBCM operation inherits the merits of both DCM and BCM. In this work, the necessary analytical equations describing the converter operation for any given condition under DBCM are derived, and are needed due to the hybrid nature of the modulation strategy during each sinusoidal wave. Based on this analysis, a design optimization sequence used to maximize the weighted efficiency of the inverter under DBCM is then applied. The design procedure is based on a power loss analysis for each converter component and focuses on the appropriate selection of the converter parameters. To achieve this, accurate, fully parameterized loss models of the converter components are implemented. The power loss analysis is then validated by applying the optimization methodology to build an experimental prototype operating in DBCM.

Download Full-text

Experimental Validations of the SiC MOSFET based LLC Converter Circuit and Power Loss Models

10.1109/wipda49284.2021.9645112 ◽

2021 ◽

Author(s):

Yuqi Wei ◽

Alan Mantooth

Keyword(s):

Power Loss ◽

Loss Models ◽

Experimental Validations

Download Full-text

A Thermomechanical Approach to Tire Power Loss Modeling

Tire Science and Technology ◽

10.2346/1.2151023 ◽

1981 ◽

Vol 9 (1) ◽

pp. 3-18 ◽

Cited By ~ 24

Author(s):

D. Whicker ◽

A. L. Browne ◽

D. J. Segalman ◽

L. E. Wickliffe

Keyword(s):

Analytical Model ◽

Fuel Economy ◽

Power Loss ◽

Thermal State ◽

Constitutive Theory ◽

Conceptual Basis ◽

Loss Model ◽

Preliminary Results ◽

Loss Models ◽

Loss Modeling

Abstract The increasing emphasis on improving fuel economy has created a need for a good analytical model for predicting tire power loss. Some of the existing tire power loss models are first reviewed and deficiencies noted, principal among these being the constitutive theory used to characterize tire materials, the model for the tire-pavement interaction, the model to account for the changing thermal state of the tire, and the model representing the interaction between the thermal and the mechanical states of the tire. The characteristics of an ideal power loss model are then outlined, its conceptual basis is presented, and the specific tasks needed to develop it and eliminate the previously listed deficiencies are discussed. Required experimental inputs to the model are enumerated. Finally, preliminary results are presented which demonstrate the feasibility of the approach.

Download Full-text

Power Loss Analysis and a Control Strategy of an Active Cell Balancing System Based on a Bidirectional Flyback Converter

Applied Sciences ◽

10.3390/app10124380 ◽

2020 ◽

Vol 10 (12) ◽

pp. 4380

Author(s):

Yu-Lin Lee ◽

Chang-Hua Lin ◽

Shih-Jen Yang

Keyword(s):

Metal Oxide ◽

Control Strategy ◽

Power Loss ◽

Metal Oxide Semiconductor ◽

Active Cell ◽

Oxide Semiconductor ◽

Flyback Converter ◽

Loss Analysis ◽

Loss Models ◽

Cell Balancing

This research proposes a power loss analysis and a control strategy of an active cell balancing system based on a bidirectional flyback converter. The system aims to achieve an energy storage application with cells connected in 6 series and 1 parrarel (6S1P) design. To reduce the structural complexity, Metal-Oxide-Semiconductor Field Effect Transistor (MOSFET) array commonly used in balancing system is replaced with the photovoltaic Metal-Oxide-Semiconductor (photoMOS) array. Power loss analysis is utilized for the system operating in the proper current to reach higher efficiency. The proposed loss models are divided into conduction loss, switching loss, and copper and core loss of the transformer. Besides, the models are used to estimate the loss of converter operating in different balance conditions to evaluate the system efficiency and verified by the implemented balancing circuit. By way of the loss models, the balancing current can be determined to reach higher efficiency of the proposed system. For further improvement of the balancing process, the system has also applied a control strategy to enhance the balancing performance that reduces 50% maximum voltage difference than traditional cell-to-pack architecture, and 47% balancing duration than traditional pack-to-cell architecture.

Download Full-text

Channel Characterization and Path Loss Modeling in Indoor Environment at 4.5, 28, and 38 GHz for 5G Cellular Networks

International Journal of Antennas and Propagation ◽

10.1155/2018/9142367 ◽

2018 ◽

Vol 2018 ◽

pp. 1-14 ◽

Cited By ~ 10

Author(s):

Mohammed Bahjat Majed ◽

Tharek Abd Rahman ◽

Omar Abdul Aziz ◽

Mohammad Nour Hindia ◽

Effariza Hanafi

Keyword(s):

Indoor Environment ◽

Large Scale ◽

Path Loss ◽

Signal Propagation ◽

Line Of Sight ◽

Frequency Bands ◽

Channel Characterization ◽

Loss Models ◽

Loss Modeling ◽

Path Loss Modeling

The current propagation models used for frequency bands less than 6 GHz are not appropriate and cannot be applied for path loss modeling and channel characteristics for frequency bands above 6 GHz millimeter wave (mmWave) bands, due to the difference of signal propagation characteristics between existing frequency bands and mmWave frequency bands. Thus, extensive studies on channel characterization and path loss modeling are required to develop a general and appropriate channel model that can be suitable for a wide range of mmWave frequency bands in its modeling parameter. This paper presents a study of well-known channel models for an indoor environment on the 4.5, 28, and 38 GHz frequency bands. A new path loss model is proposed for the 28 GHz and 38 GHz frequency bands. Measurements for the indoor line-of-sight (LOS) and non-line-of-sight (NLOS) scenarios were taken every meter over a separation distance of 23 m between the TX and RX antenna locations to compare the well-known and the new large-scale generic path loss models. This measurement was conducted in a new wireless communication center WCC block P15a at Universiti Teknologi Malaysia UTM Johor, Malaysia, and the results were analyzed based on the well-known and proposed path loss models for single-frequency and multifrequency models and for directional and omnidirectional path loss models. Results show that the large-scale path loss over distance could be modeled better with good accuracy by using the simple proposed model with one parameter path loss exponent PLE (n) that is physically based to the transmitter power, rather than using the well-known models that have no physical base to the transmitted power, more complications (require more parameters), and lack of anticipation when explaining model parameters. The PLE values for the LOS scenario were 0.92, 0.90, and 1.07 for the V-V, V-H, and V-Omni antenna polarizations, respectively, at the 28 GHz frequency and were 2.30, 2.24, and 2.40 for the V-V, V-H, and V-Omni antenna polarizations, respectively, at the 38 GHz frequency.

Download Full-text