In-service cable-monitoring technique for hybrid fiber/coaxial networks based on frequency domain analysis incorporated with optical time-domain reflectometer and fiber benders

2000 ◽  
Vol 39 (2) ◽  
pp. 374
Author(s):  
Sien Chi
Energies ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3606
Author(s):  
Jing-Yuan Lin ◽  
Chuan-Ting Chen ◽  
Kuan-Hung Chen ◽  
Yi-Feng Lin

Three-phase wye–delta LLC topology is suitable for voltage step down and high output current, and has been used in the industry for some time, e.g., for server power and EV charger. However, no comprehensive circuit analysis has been performed for three-phase wye–delta LLC. This paper provides complete analysis methods for three-phase wye–delta LLC. The analysis methods include circuit operation, time domain analysis, frequency domain analysis, and state–plane analysis. Circuit operation helps determine the circuit composition and operation sequence. Time domain analysis helps understand the detail operation, equivalent circuit model, and circuit equation. Frequency domain analysis helps obtain the curve of the transfer function and assists in circuit design. State–plane analysis is used for optimal trajectory control (OTC). These analyses not only can calculate the voltage/current stress, but can also help design three-phase wye-delta connected LLC and provide the OTC control reference. In addition, this paper uses PSIM simulation to verify the correctness of analysis. At the end, a 5-kW three-phase wye–delta LLC prototype is realized. The specification of the prototype is a DC input voltage of 380 V and output voltage/current of 48 V/105 A. The peak efficiency is 96.57%.


2014 ◽  
Vol 4 (4) ◽  
pp. 295-299 ◽  
Author(s):  
D. J. Passos ◽  
S. O. Silva ◽  
J. R. A. Fernandes ◽  
M. B. Marques ◽  
O. Frazão

2014 ◽  
Vol 12 (02) ◽  
pp. 1461014 ◽  
Author(s):  
Fabrizio Piacentini ◽  
Alice Meda ◽  
Paolo Traina ◽  
Hong Kee Suk ◽  
Ivo Pietro Degiovanni ◽  
...  

This paper presents the INRIM effort related to the implementation of an optical time domain reflectometer (OTDR) that exploits backscattered light to test an optical fiber operating at single photon level, using two different avalanche photodetectors: a free-running Id220 and a gated Id201. Our tests show that the use of the Id220-based OTDR could be very helpful for QKD application, since it allows testing much longer portions of an optical link. This represents a great advantage for QKD systems, where single components and connections are often embedded in a non-separable optical system.


Sign in / Sign up

Export Citation Format

Share Document