scholarly journals Frequency measurement of acetylene-stabilized lasers using a femtosecond optical comb without carrier-envelope offset frequency control

2005 ◽  
Vol 13 (6) ◽  
pp. 1958 ◽  
Author(s):  
Jie Jiang ◽  
Atsushi Onae ◽  
Hirokazu Matsumoto ◽  
Feng-Lei Hong
Keyword(s):  
Frequency Control ◽  
Frequency Measurement ◽  
Offset Frequency

A Decentralized Load Frequency Control Method by Means of Frequency Measurement of Adjacent Power Systems

1988 ◽  
Vol 21 (11) ◽  
pp. 387-393 ◽  
Author(s):  
H. Sasaki ◽  
H. Yorino ◽  
T. Suizu ◽  
S. Yurino ◽  
R. Yokoyama ◽  
...  
Keyword(s):  
Power Systems ◽  
Control Method ◽  
Frequency Control ◽  
Frequency Measurement ◽  
Load Frequency Control ◽  
Load Frequency

scholarly journals Automatic Coordination of Internet-Connected Thermostats for Power Balancing and Frequency Control in Smart Microgrids

Energies ◽  
2019 ◽  
Vol 12 (10) ◽  
pp. 1936 ◽  
Author(s):  
Saeid Bashash ◽  
Kai Lun Lee
Keyword(s):  
Frequency Control ◽  
Supply And Demand ◽  
Peak Load ◽  
Weather Conditions ◽  
Frequency Measurement ◽  
Power Generators ◽  
Generation Cost ◽  
Generation Capacity ◽  
Feedback Control Strategy ◽  
The Individual

This paper proposes a novel feedback control strategy, so-called clock-like controller (CLC), to balance power supply and demand in smart microgrids by adjusting the setpoint temperatures of air conditioning (AC) loads. In the CLC algorithm, the grid operator communicates with the individual thermostats via the Internet and adjusts their setpoints by discrete temperature intervals (e.g., ±0.5 °C). Numerical simulations indicate that the proposed algorithm is able to deliver a smooth controllability of the aggregate AC power despite discrete temperature offsets. It can also be used for peak load shedding to mitigate the power generation cost. The CLC algorithm is then integrated into the grid frequency control problem, in which both power generators and loads in the network attempt to regulate the frequency of the system despite disturbances from demand, renewable sources, and local weather conditions. An autonomous microgrid model including a steam and a hydro generator, a solar energy source, and a large number of thermostatic loads is developed to evaluate and demonstrate the proposed method. Simulation results indicate that the AC loads with CLC algorithm can help maintain the power system frequency during extreme events when demand exceeds the maximum generation capacity available to the network. Under normal conditions, the contribution of demand-side control is marginalized by the fast responding generators, because of time delays in the frequency measurement and internet communication network.

scholarly journals Load Frequency Control of HVDC Link Interconnected Power System Using Genetic Algorithm

MENDEL ◽  
2019 ◽  
Vol 25 (1) ◽  
pp. 131-138
Author(s):  
Saurabh Chanana ◽  
Saurabh Kumar
Keyword(s):  
Genetic Algorithm ◽  
Power System ◽  
Frequency Control ◽  
Frequency Measurement ◽  
Control Area ◽  
Load Frequency Control ◽  
Support Functions ◽  
Interconnected Power System ◽  
Load Frequency ◽  
Tie Line

Advances in power electronics have improved grid support functions such as tie-line power control and frequency control, making renewable generation and High Voltage DC (HVDC) links more common in power system applications. Load Frequency Control (LFC) systems handle the complex interactions between the distributed generator and the control area with the HVDC link. In this work, LFC of a two-zone system including parallel AC/DC transmission links has been analysed. The parameters of this system are optimised using advanced genetic algorithm resulting in improved performance of system in terms of reduction in peak overshoots and settling time of frequency measurement, tie line power flow and area control error signals in an interconnected power system. The advantage of having parallel HVDC links is also demonstrated when performance is compared to system interconnected with only AC tie line.

Countdown Frequency Measurement and its Application in Radar AFC

2014 ◽  
Vol 556-562 ◽  
pp. 2650-2653
Author(s):  
Xiong Shi
Keyword(s):  
Control System ◽  
High Stability ◽  
Frequency Control ◽  
Electric Circuit ◽  
Frequency Measurement ◽  
Crystal Oscillator ◽  
Digital Frequency ◽  
Frequency Control System ◽  
Time Standard ◽  
Radar Frequency

High stability and constant-temperature crystal oscillator as time standard, microcontroller as control core, the countdown frequency measuring electric circuit, rapidly and timely surveying the transmitting frequency during the constant radar transmitted pulse, is a digital frequency measurement module. This module is an important constituent part in digital automatic radar frequency control system, having been successfully applied in a self-adaption frequency control system of meter wave warning radar.

scholarly journals Supercontinuum generation and carrier envelope offset frequency measurement in a tapered single-mode fiber

2014 ◽  
Vol 117 (4) ◽  
pp. 1183-1187 ◽  
Author(s):  
Long Zhang ◽  
Hainian Han ◽  
Yanying Zhao ◽  
Lei Hou ◽  
Zijiao Yu ◽  
...  
Keyword(s):  
Single Mode ◽  
Frequency Measurement ◽  
Supercontinuum Generation ◽  
Single Mode Fiber ◽  
Offset Frequency

Principle and Realization of Frequency Measuring with Countingdown Method

2014 ◽  
Vol 556-562 ◽  
pp. 2693-2696
Author(s):  
Lian Xiang Xu ◽  
Xiong Shi
Keyword(s):  
Integrated Circuit ◽  
Frequency Control ◽  
Intermediate Frequency ◽  
Frequency Measurement ◽  
Single Chip ◽  
Transmission Frequency ◽  
Square Wave ◽  
Frequency Control System ◽  
Standard Pulse ◽  
Down Conversion

The intermediate frequency signal, which is generated by down conversion of radar transmission pulse, is settled as square wave through the signal processing circuit; in N cycle of the unknown square wave of this frequency, the frequency measurement circuit with counting down method uses the counter and the time-sequence control circuit consisting of TTL integrated circuit, such as F161 and LS221, to count the standard pulse exported by homothermal crystal with high stability and then load the result in single chip in order to obtain the frequency measuring result. This frequency measuring circuits, a digital frequency measurement module, can rapidly and timely survey the transmission frequency during the constant radar transmission pulse and has been successfully applied in a self-adaption frequency control system of meter wave warning radar.

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