A Novel Method for Investigating the Frequency Dependent Behavior of Instrument Transformers

2014 ◽  
Vol 494-495 ◽  
pp. 1477-1481
Author(s):  
Yong Xin Feng ◽  
Zhao Li ◽  
Ya Qi Gao ◽  
Bing Ran Shao ◽  
Xue Wen Ding ◽  
...  
Keyword(s):  
Measurement System ◽  
Current Transformers ◽  
Frequency Dependent ◽  
Frequency Responses ◽  
System A ◽  
Dependent Behavior ◽  
Instrument Transformers ◽  
Computer Based ◽  
Novel Method ◽  
High Voltage System

This paper describes the structure and the principle of the NI DAQ based measurement system used for investigating the frequency dependent behavior of instrument transformers in the high voltage system. A computer based NI DAQ card is utilized as the data acquisition system in the new measurement system. The software digital filter and the phase locked loop are implemented to obtain the magnitude and phase angle, respectively. With this measurement system, we investigated frequency responses of several voltage and current transformers at the converter station of the Germany railway.

scholarly journals Decentralized Optimization for a Novel Control Structure of HVAC System

2016 ◽  
Vol 2016 ◽  
pp. 1-13 ◽  
Author(s):  
Shiqiang Wang ◽  
Jianchun Xing ◽  
Ziyan Jiang ◽  
Juelong Li
Keyword(s):  
Control System ◽  
Decentralized Control ◽  
Control Structure ◽  
Optimization Method ◽  
Labor Cost ◽  
Smart Device ◽  
Hvac System ◽  
Decentralized Optimization ◽  
System A ◽  
Novel Method

A decentralized control structure is introduced into the heating, ventilation, and air conditioning (HVAC) system to solve the high maintenance and labor cost problem in actual engineering. Based on this new control system, a decentralized optimization method is presented for sensor fault repair and optimal group control of HVAC equipment. Convergence property of the novel method is theoretically analyzed considering both convex and nonconvex systems with constraints. In this decentralized control system, traditional device is fitted with a control chip such that it becomes a smart device. The smart device can communicate and operate collaboratively with the other devices to accomplish some designated tasks. The effectiveness of the presented method is verified by simulations and hardware tests.

DETERMINING ROBUST PARAMETERS IN STABILIZING SET OF BACKSTEPPING BASED NONLINEAR CONTROLLER FOR SHIP COURSE KEEPING

2021 ◽  
Vol 158 (A3) ◽  
Author(s):  
X K Zhang ◽  
G Q Zhang
Keyword(s):  
Closed Loop ◽  
Simulation Experiment ◽  
Empirical Knowledge ◽  
Backstepping Method ◽  
Nonlinear Controller ◽  
Closed Loop System ◽  
Robust Performance ◽  
System A ◽  
Uniformly Asymptotic Stability ◽  
Novel Method

In order to solve the problem that backstepping method cannot effectively guarantee the robust performance of the closed-loop system, a novel method of determining parameter is developed in this note. Based on the ship manoeuvring empirical knowledge and the closed-loop shaping theory, the derived parameters belong to a reduced robust group in the original stabilizing set. The uniformly asymptotic stability is achieved theoretically. The training vessel “Yulong” and the tanker “Daqing232” are selected as the plants in the simulation experiment. And the simulation results are presented to demonstrate the effectiveness of the proposed algorithm.

The thrust measurement system research for combined nozzle in small space

2018 ◽  
Vol 41 (4) ◽  
pp. 1149-1159
Author(s):  
Yonghua Lu ◽  
Jing Li ◽  
Xiang Zhang ◽  
Yang Li
Keyword(s):  
Measurement System ◽  
Force Sensor ◽  
Test Method ◽  
Small Space ◽  
System A ◽  
Calibration Experiment ◽  
Different Types ◽  
Thrust Measurement ◽  
Nozzle Thrust ◽  
Thrust Forces

For measuring the thrust of combined nozzles in satellite thruster with a small space, the test method that the nozzle directly sprays on the load baffle is employed in this paper. The key problem is how to design the positions of 10 load baffles and how to construct the measurement system. A set of complete and automatic nozzle thrust measurement system is designed and built, and the influence of the load baffle applied on the flow field of nozzles is analyzed using the software FLUENT. Furthermore, the load surface locations of the sensors for the different types of nozzles are analyzed. We draw the conclusion that the load baffle position should range from 4–8 mm for the I-type nozzle and range in 6–12 mm for II-type and III-type nozzle. The correction coefficients of the thrust forces for all channels of the measurement system are determined in the calibration experiment. The uncertainty of measurement system is estimated and the error source of the measurement system is traced. We found that the systematic uncertainty is mainly contributed by the A-type uncertainty which is related with the nozzle dimension and its inner structure. The B-type uncertainty of system is contributed by the force sensor.

scholarly journals Estimating the frequency dependent behavior of marine sediment sound speeds using low frequency aircraft sound

2008 ◽  
Vol 123 (5) ◽  
pp. 3349-3349
Author(s):  
Alireza Amiri‐Simkooei ◽  
Mirjam Snellen ◽  
Dick G. Simons ◽  
Michael Buckingham
Keyword(s):  
Marine Sediment ◽  
Low Frequency ◽  
Frequency Dependent ◽  
Sound Speeds ◽  
Dependent Behavior

scholarly journals A Novel Method to Evaluate Patient-Ventilator Synchrony during Mechanical Ventilation

Complexity ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
Liming Hao ◽  
Shuai Ren ◽  
Yan Shi ◽  
Na Wang ◽  
Yixuan Wang ◽  
...  
Keyword(s):  
Mechanical Ventilation ◽  
Ventilation System ◽  
Future Research ◽  
Evaluation Indexes ◽  
Response Parameter ◽  
System A ◽  
Clinical Strategies ◽  
The Future ◽  
Novel Method ◽  
Ventilator Synchrony

The synchrony of patient-ventilator interaction affects the process of mechanical ventilation which is clinically applied for respiratory support. The occurrence of patient-ventilator asynchrony (PVA) not only increases the risk of ventilator complications but also affects the comfort of patients. To solve the problem of uncertain patient-ventilator interaction in the mechanical ventilation system, a novel method to evaluate patient-ventilator synchrony is proposed in this article. Firstly, a pneumatic model is established to simulate the mechanical ventilation system, which is verified to be accurate by the experiments. Then, the PVA phenomena are classified and detected based on the analysis of the ventilator waveforms. On this basis, a novel synchrony index SIhao is established to evaluate the patient-ventilator synchrony. It not only solves the defects of previous evaluation indexes but also can be used as the response parameter in the future research of ventilator control algorithms. The accurate evaluation of patient-ventilator synchrony can be applied to the adjustment of clinical strategies and the pathological analyses of patients. This research can also reduce the burden on clinicians and help to realize the adaptive control of the mechanical ventilation and weaning process in the future.

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