Use of spatial phase difference method to detect microwaves associated with stator coil partial discharge in a generator

This paper presents a new system for detecting electromagnetic waves emitted from partial discharges (PD) due to material defects in high-voltage electric machinery and apparatus. PD is a symptom and/or a direct cause of the deterioration of insulation systems used in high-voltage stator coils. This system can detect PD by using the spatial phase information of the microwaves emitted from PD, which are voltage pulses of very short duration. We describe the properties of this system which is composed of two double-ridge-guide-horn antennas, two preamplifiers, a gigahertz interference receiver (GHz-2ch-down-converter) of original design, two A/D (analog to digital) converters, and a personal computer. We experimentally show that this system can be used for detection of the microwaves emitted by PD occurring in the stator coil. The result of this work is the development of a new noncontact PD detection system for generators, which can be operated by station personnel. © 1997 Scripta Technica, Inc. Electr Eng Jpn, 121(2): 16–26, 1997     

Dynamic cell sleeping mechanism: An energy-efficient approach for Mobile 5G HetCN

The paper proposes a novel cell sleeping mechanism for enhancing network energy-efficiency and to combat dynamic downlink interferences linked with mobile Small Cells (mSCs) in a 5G Heterogeneous Cellular Network (HetCN). The proposed Dynamic Mobile Cell Sleeping Mechanism (DMCSM) allows deployed vehicle-mounted mSCs to dynamically go into sleep based on the calculated distances of users from its serving mSCs BS. With this mechanism, vehicular mSCs during mobility dynamically calculate their distances with the Macrocell (MC) users. The mSCs go into sleep or get deactivated for a while based on the calculated distance and the cell radius defined for mSCs. The mSCs will get active and starts to provide services to the users that are found within their coverage radius. The setup 5G HetCN is investigated with a MC superimpose with fixed SCs (fSCs) and mobile SCs (mSCs). The proficiency of DMCSM is investigated with the exploitation of existing sub 6 GHz groups at MCs and the millimeter wave (mmWave) spectrums at deployed fSCs and mSCs. The network downlink performance metrics: user throughput, sumrate, energy-efficiency, and outage probability, have been explored. The work also depicts a comparison of the proposed DMCSM mechanism with the author's previously proposed ICI mitigation techniques.