Intelligent Control Circuit Integral with Pattern Recognition Techniques for High-Pressure Sodium Lamps

2017 ◽  
Vol 26 (07) ◽  
pp. 1750108
Author(s):  
Yuzhuo Pan ◽  
Chen Lv ◽  
Shanhe Su ◽  
Jincan Chen
Keyword(s):  
Pattern Recognition ◽  
High Pressure ◽  
Intelligent Control ◽  
High Frequency ◽  
Pulse Width Modulation ◽  
Smart Cities ◽  
Control Strategies ◽  
Low Frequency ◽  
Acoustic Resonance ◽  
Working Device

The paper presents the analysis, simulation, and experimental methods to eliminate acoustic resonance in high-frequency high-pressure sodium (HPS) lamps and integrate intelligent control strategies in the working device. Based on the pulse-width modulation (PWM) output generated by the microcontroller, the acoustic resonance in the high-frequency lamp can be successfully eliminated by modulating the high-frequency driving current via a low-frequency signal. Particularly, by implementing the pattern recognition, the control system enables the lamp to have the abilities of accurate timing, gradient dimming, automatic protection, and intellisense. The proposed model will provide useful information for designing intelligent lighting system towards smart cities.

The Investigation of the Optimization Scheme of the Low-cycle Fatigue Cropping Based on the Acoustic Emission Technique

2021 ◽  
Author(s):  
Yujian Ren ◽  
Jingxiang Li ◽  
Yuanzhe Dong ◽  
Dong Jin ◽  
Shengdun Zhao
Keyword(s):  
Acoustic Emission ◽  
High Frequency ◽  
Control Method ◽  
Low Cycle Fatigue ◽  
Control Strategies ◽  
Low Frequency ◽  
Loading Frequency ◽  
Cycle Fatigue ◽  
Al 6061 ◽  
Whole Process

Abstract High efficiency and good section quality are two main objectives of metal bar cropping. A suitable control method can help to achieve both goals. An investigation of the control method of low-cycle fatigue cropping (LCFC) based on the acoustic emission (AE) technique has been proposed in this study. Ring-down counts and kurtosis are used to monitor the whole process of LCFC. The results showed that kurtosis is more suitable for monitoring the LCFC process and as a critical parameter to optimize the control method than ring-down counts in the noisy factory environment.Moreover, three types of materials are studied in this experiment; by combine with the AE results, macroscopic images and microscopic images of sections, characteristics of various LCFC stages are obtained. The results also indicated reduce the area of the transient fracture zone is the key to improve the section quality. Reducing the load frequency before the unstable crack propagation stage will beneficial to realize the goals. Based on the evaluation of kurtosis, an optimized control method is presented, and two control parameters: transient time T and the critical value of the slope of kurtosis C are determined. For 16Mn, 1045 and Al 6061, the T is 5s, 10s, and 1s, respectively. For 16Mn, 1045, and Al 6061, the C is 100, 300, and 0, respectively. Two parameters, h and S, are used to evaluate the section quality and four control strategies are compared. The results indicate the optimal control methods can improve the section quality effectively. The influence trend of reducing loading frequency is investigated by further comparison. It can be seen as the frequency decreases, the efficiency of the section quality improving decreases. In order to realize the optimal results, different control strategies are adopted for different materials. Strategy 1 (high frequency is 20Hz，high frequency thought the whole process), strategy 2 (high frequency is 20Hz，low frequency is 8.33Hz), and strategy 3 (high frequency is 20Hz，low frequency is 6.67Hz) is suitable for Al 6061, 1045, and 16Mn, respectively.

Simulation And Development Of Electronic Ballast for High Pressure Discharge Lamps

2021 ◽  
pp. 86-92
Author(s):  
Vladimir G. Kulikov ◽  
Albert A. Ashryatov
Keyword(s):  
High Pressure ◽  
High Frequency ◽  
Acoustic Resonance ◽  
High Frequency Current ◽  
Electronic Ballast ◽  
Advantages And Disadvantages ◽  
Test Operation ◽  
Pressure Discharge ◽  
Frequency Current ◽  
High Pressure Discharge

The advantages and disadvantages of using electromagnetic ballasts for power supply of high pressuredischarge lamps (HPDL) are considered. The advantages of using electronic ballasts for supplying HPDL are shown. The analysis is fulfilled of the operation of the HPDL when powered by a high-frequency current, in particular, high-pressure sodium lamps (HPSL). It is indicated that when high-pressure discharge lamps are supplied with a high-frequency current, acoustic resonance may appear. The basic requirements to be met by electronic ballasts for HPSL have been determined. The topology of construction of electronic ballasts for supplying HPDL with a capacity of up to 1 kW has been selected. It has been established that half-bridge converters with inductive ballast and active power factor corrector (PFC) allow maintaining a stable power on the lamp while changing its parameters and efficiency. Mathematical modelling of the electronic ballast based on a half-bridge converter and an ignition device for the sodium discharge lamps DNaT type has been carried out. According to the proposed topology, the electronic ballast was developed for a DNaT 600 lamp powered from the 380 V network. Test operation of the lamps confirmed the reliability of the proposed electronic ballast topology.

A design methodology for acoustic resonance-free, high-frequency, dimmable electronic ballast for high-pressure sodium-vapour lamps

2019 ◽  
Vol 52 (4) ◽  
pp. 524-539
Author(s):  
B Gupta Bakshi ◽  
B Roy
Keyword(s):  
High Pressure ◽  
High Frequency ◽  
Design Methodology ◽  
Power Level ◽  
Harmonic Distortion ◽  
Acoustic Resonance ◽  
Electrical Characteristics ◽  
Electronic Ballast ◽  
Lamp Current ◽  
Sodium Vapour

This paper presents a methodology to design acoustic resonance-free, high-frequency, dimmable electronic ballasts for high-pressure sodium vapour (HPSV) lamps having a range of rated wattage (70–400 W). After estimation of the ‘quiet window’ of an HPSV lamp, the proposed iterative algorithm is able to determine the acoustic resonance-free driving frequencies of a design ballast corresponding to 50%–100% power level. On the other hand, a developed wattage and voltage independent HPSV lamp model facilitates finding the required electrical characteristics of HPSV lamps without performing laboratory experimentation. Using the estimated driving frequencies of a design ballast and the synthesized electrical characteristics of the lamp, the design circuit parameters of an electronic ballast are determined. Performance evaluation of the designed ballasts, carried out on the Matlab–Simulink platform, indicates several important attributes, viz. higher power control accuracy (deviation ≤3.69%), near-unity lamp power factor (≥0.98), lower lamp current crest factor (<1.7) and lower lamp current total harmonic distortion (≤12.63%). Results establish the effectiveness of the proposed design methodology to design lightweight and compact electronic ballasts for HPSV lamps with less effort than conventional design practice.

Fluctuating Pressure Generating in BWR Main Steam Lines Acoustic Excited by Safety Relief Valve Stub Pipes and Dead Legs

2010 ◽  
Author(s):  
Shiro Takahashi ◽  
Keita Okuyama ◽  
Akinori Tamura ◽  
Masaya Ohtsuka ◽  
Masaaki Tsubaki ◽  
...  
Keyword(s):  
Flow Velocity ◽  
High Frequency ◽  
Acoustic Analysis ◽  
Low Frequency ◽  
Sound Field ◽  
Acoustic Resonance ◽  
Operating Conditions ◽  
Relief Valve ◽  
Fluctuating Pressure ◽  
Main Steam

During operation, the BWR-3 steam dryer in the Quad Cities Unit 2 Nuclear Power Plant was damaged by high cycle fatigue. The dryer failure was attributed to flow-induced acoustic resonance at the stub pipes of safety relief valves (SRVs) in the main steam lines (MSLs). The acoustic resonance was considered to be generated by interaction between the sound field and an unstable shear layer across the closed side branches with SRV stub pipes. We HITACHI and CRIEPI have started a research program on BWR dryers to develop their loading evaluation methods. Moreover, it has become necessary to evaluate the dryer integrity of BWR-5 plants in particular which are the main type of BWR in Japan. In the present study, we used 1/10-scale BWR tests and analyses to investigate the flow-induced acoustic resonance and characteristics of fluctuating pressure in MSLs. The test apparatus consisted of a steam dryer, a steam dome and 4 MSLs with 20 SRV stub pipes. A finite element method (FEM) was applied for the calculation of three-dimensional wave equations in acoustic analysis. We demonstrated that remarkable fluctuating pressures occurred in high and low frequency regions. Intensity of three peaks observed in the spectrum of fluctuating pressure in MSLs was increased with St. High frequency fluctuating pressures were generated by the flow-induced acoustic resonance in the SRV stub pipes. Low frequency fluctuating pressures were excited by the acoustic resonance in the dead leg. Frequency of fluctuating pressure generating in the SRV stub pipe was changed with St. On the other hand, frequency of fluctuating pressure excited by dead leg was almost constant. Fluctuating pressure in low frequency range increased gradually with flow velocity and its intensity was roughly proportional to the square of flow velocity. The flow-induced acoustic resonance did not occur for St larger than 0.6 in the BWR MSLs for both low and high frequency ranges. Operating conditions of the BWR-5 from 100 to 115% were in the range of St larger than 0.6, so intense acoustic resonance would not occur in the BWR MSLs.

Search Time as a Function of Context Letter Frequency

Perception ◽  
1972 ◽  
Vol 1 (1) ◽  
pp. 57-71 ◽  
Author(s):  
C R Latimer
Keyword(s):  
Pattern Recognition ◽  
Reaction Time ◽  
High Frequency ◽  
Relative Frequency ◽  
Search Time ◽  
Low Frequency ◽  
Frequency Of Occurrence ◽  
Template Model ◽  
Letter Frequency ◽  
Feature Frequency

Neisser (1967) posits the operation of purely feature analytic processes in the scanning of context letters in search lists. This contention was tested by varying the relative frequency of occurrence in English of the context letters in alphanumeric search lists, while holding their feature content constant. It was hypothesized that faster search time on lists of high-frequency context letters would indicate letter-level processing. Equality of search time would indicate the purely feature-level processing required by Neisser's theory. Context letters were segregated into high- and low-frequency sets and their features defined and held constant according to two feature analyses. This yielded a 2 × 2 design with 22 subjects per condition. Attention was given to the control of feature frequency, size of the context-letter set, and approximation of English at the level of bigram, trigram, and word. Results supported a letter level or template model of processing but were shown also to be explainable in terms of some feature-testing models of pattern recognition. Apparatus which allowed for the removal of reaction time in search lists is described.

Dynamic Positioning Systems: Comparison Between Wave Filtering Algorithms and Their Influence on Performance

2003 ◽  
Author(s):  
Eduardo A. Tannuri ◽  
Tiago T. Bravin ◽  
Celso P. Pesce
Keyword(s):  
Analog Circuits ◽  
High Frequency ◽  
Control Strategies ◽  
Low Frequency ◽  
Design Parameters ◽  
Dynamic Positioning ◽  
Frequency Wave ◽  
Filtering Algorithms ◽  
Positioning Systems ◽  
Dynamic Positioning System

Wave filtering is an essential function of a Dynamic Positioning System, being responsible for the separation between high-frequency wave induced motions and low-frequency ones, which must be controlled. Low attenuation of the first components may cause oscillatory control action, high fuel consumption and can damage propeller systems. On the other hand, depending on filtering design, high levels of attenuation may be associated with non-admissible delay-times, which may cause instability in the closed-loop system. Traditionally, low-pass or notch-type filters have been used since the first DP systems, due to the simplicity, acceptable performance and possibility of being implemented using analog circuits. Alternatively, observers based on Kalman Filtering Theory have also been used, based on simplified ship models, separating low and high frequency motions. Two wave filters, representing each of those categories, were implemented in a complete DP simulator. All DP components and algorithms are considered and modeled in the simulator, including propellers, thrust allocation, wind-feedforward and different control strategies. Environmental loads are evaluated using fully validated models, including wind, current and wave actions. A pipe-laying barge under typical Campos Basin environmental conditions has been considered as example. Several aspects of the filtering algorithms were analyzed and compared, involving the influence of each filter in the overall DP performance, relationship of design parameters with physical system, ease of commissioning and tuning. The trade off between low frequency tracking (which is associated with the delay time) and wave response suppression is analyzed and discussed for both categories of filters.

scholarly journals Performance Analysis of Different Filters for Digital Image Processing

2021 ◽  
Vol 12 (2) ◽  
pp. 2572-2576
Author(s):  
Ch. Kavya , Et. al.
Keyword(s):  
Remote Sensing ◽  
Image Processing ◽  
Pattern Recognition ◽  
Digital Image Processing ◽  
Digital Image ◽  
High Frequency ◽  
Satellite Remote Sensing ◽  
Low Frequency ◽  
Linear Filters

Digital image processing is one of the drastically growing areas used in various real- time industries like medical, satellite, remote sensing, and pattern recognition. The output of the image processing depends on the quality of the image. Filters are used to modify the images, such as removing the noise and smoothing the images. It is essential to suppress the high- frequency values in the image for smoothening and improving the low-frequency values to enhance the image of strengthening else it doesn't provide good output. This paper discussed various filters and their functionalities concerning digital image processing. Here linear, as well as non-linear filters, are presented. It is easy to decide about the better filter for improving the image processing output from the discussion.

scholarly journals Hybrid PWM Strategy for Power Efficiency Improvement of 5-Level TNPC Inverter and Current Distortion Compensation Method

Electronics ◽  
2019 ◽  
Vol 8 (1) ◽  
pp. 76 ◽  
Author(s):  
Taeyeong Lee ◽  
Hanyoung Bu ◽  
Younghoon Cho
Keyword(s):  
High Frequency ◽  
Power Efficiency ◽  
Pulse Width Modulation ◽  
Low Frequency ◽  
Compensation Method ◽  
Switching Frequency ◽  
Efficiency Improvement ◽  
Switching Loss ◽  
Distortion Compensation ◽  
Output Filter

This paper proposes a pulse width modulation (PWM) strategy for improving the efficiency of a 5-level H-bridge T-type neutral point clamped (TNPC) inverter. In the case of the proposed PWM strategy, unlike the conventional PWM strategy in which both of the switching legs of the H-bridge inverter operate at a high frequency, one switching leg of the inverter operates at a low frequency. As the switching frequency is lowered, the switching loss is reduced, this improving the efficiency of the system. The duty references for the switching legs and the operating principle of the inverter are described in detail. The proposed PWM strategy, however, causes distortion of the output filter inductor current. The cause of the distortion has been analyzed and a compensation method is proposed to mitigate the distortion of the current. The effect of the proposed PWM strategy can be predicted through the loss calculation of the inverter for each modulation strategy. Furthermore, current distortion mitigation obtained by compensation method is confirmed through the simulation. In order to verify the effectiveness of the proposed strategy, a 2 kW H-bridge TNPC inverter prototype is implemented and tested. The simulation and experimental results show that the efficiency of the inverter is improved when the proposed PWM strategy is applied.

scholarly journals Hybrid Pattern Recognition and Multi-resolution Analysis (MRA) Based Fault Location in Power Transmission Lines

2019 ◽  
pp. 1-14
Author(s):  
Jude I. Aneke ◽  
O. A. Ezechukwu ◽  
P. I. Tagboh
Keyword(s):  
Neural Network ◽  
Pattern Recognition ◽  
Transmission Lines ◽  
High Frequency ◽  
Fault Location ◽  
Power Transmission ◽  
Low Frequency ◽  
Power Transmission Lines ◽  
Multi Resolution Analysis ◽  
Resolution Analysis

This paper proposes a fault (line-to-line) location on Ikeja West – Benin 330kV electric power transmission lines using wavelet multi-resolution analysis and neural networks pattern recognition abilities. Three-phase line-to-line current and voltage waveforms measured during the occurrence of a fault in the power transmission-line were pre-processed first and then decomposed using wavelet multi-resolution analysis to obtain the high-frequency details and low-frequency approximations. The patterns formed based on high-frequency signal components were arranged as inputs of the neural network, whose task is to indicate the occurrence of a fault on the lines. The patterns formed using low-frequency approximations were arranged as inputs of the second neural network, whose task is to indicate the exact fault type. The new method uses both low and high-frequency information of the fault signal to achieve an exact location of the fault. The neural network was trained to recognize patterns, classify data and forecast future events. Feed forward networks have been employed along with back propagation algorithm for each of the three phases in the Fault location process. An analysis of the learning and generalization characteristics of elements in power system was carried using Neural Network toolbox in MATLAB/SIMULINK environment. Simulation results obtained demonstrate that neural network pattern recognition and wavelet multi-resolution analysis approach are efficient in identifying and locating faults on transmission lines as the average percentage error in fault location was just 0.1386%. This showed that satisfactory performance was achieved especially when compared to the conventional methods such as impedance and travelling wave methods.

A Bidirectional UPS Inverter Utilising High Frequency Center–Tapped Transformer

2012 ◽  
Author(s):  
Zainal Salam ◽  
Zulkifli Ramli
Keyword(s):  
High Frequency ◽  
Pulse Width Modulation ◽  
Low Frequency ◽  
Frequency Component ◽  
Modulation Method ◽  
Full Potential ◽  
Power Circuit ◽  
Active Rectifier ◽  
High Frequency Transformer ◽  
Transformer Design

A new variation of transformer-isolated inverter for UPS application is proposed. It is basically similar to the circuit proposed by Kourtroulis with the following modifications: 1) a modified modulation technique for the HF PWM interver stage and 2) replacing the full bridge active rectifier witha center-tapped active rectifier. With these modifications, the switches count is reduced, and expectedly, the efficiency is increased. Futhermore, the modified PWM technique will ensure that the transformer can be utilised near to its full potential. This is due to be absence of the low frequency component that can result in transformer saturation. The paper will detail the design considerations for the proposed topology. It will primarily focus on the power circuit, modulation method, and the high frequency transformer design. To prove the concept, a 1–kW prototype inverter was built and tested. Keywords: Inverter, bidirectional, high frequency transformer, pulse width modulation

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