scholarly journals Multiphase Z-source inverter using maximum constant boost control

2013 ◽  
Vol 23 (1) ◽  
pp. 107-126 ◽  
Author(s):  
Abdellah Kouzou ◽  
Haitham Abu-Rub
Keyword(s):  
Real Time ◽  
Duty Cycle ◽  
Output Voltage ◽  
Control Method ◽  
Induction Machine ◽  
The Other ◽  
Resistive Load ◽  
Phase Inverter ◽  
Boost Control ◽  
The Impact

Abstract This paper deals with the impedance source (Z-source) multiphase inverter, where the maximum constant boost control method is studied and analyzed in the general case of number of phases. On the other side the impact of the modulation index and the number of phases on the duty cycle shoot-through and on the gain of the output voltage ranges is presented. To validate advantages of the Z-source multiphase inverter, the proposed topology and the maximum constant boost control are implemented in simulation and in real time experimentation with Z-source five phase inverter. The output voltage is applied to two parallel loads, a five phase resistive load and a five phase induction machine.

Proposed Topology for Voltage Sag Mitigation with New Control Strategy

2019 ◽  
Vol 15 (2) ◽  
pp. 138-144
Author(s):  
Adnan Diwan ◽  
Khalid Abdulhasan
Keyword(s):  
Duty Cycle ◽  
Control Strategy ◽  
Output Voltage ◽  
System Analysis ◽  
Control Method ◽  
Boost Converter ◽  
Voltage Sag ◽  
Voltage Sags ◽  
Long Duration ◽  
Simulation Results

voltage sags represent the greatest threat to the sensitive loads of industrial consumers, the microprocessor based-loads, and any electrical sensitive components. In this paper, a special topology is proposed to mitigate deep and long duration sags by using a modified AC to AC boost converter with a new control method. A boost converter is redesigned with a single switch to produces an output voltage that is linearly proportional to the duty cycle of the switch. On the other hand, the proposed control system is based on introducing a mathematical model that relates the missing voltage to the duty cycle of the boost converter switch. The simulation results along with the system analysis are presented to confirm the effectiveness and feasibility of the proposed circuit.

The Design of a 150V/50Hz High-Quality Single-Phase Inverter Based on TMS320LF2407A

2012 ◽  
Vol 433-440 ◽  
pp. 3728-3733
Author(s):  
Zhen Wang ◽  
Ling Shun Liu
Keyword(s):  
Power Supply ◽  
Output Voltage ◽  
Single Phase ◽  
Control Method ◽  
Power Module ◽  
High Quality ◽  
Phase Inverter ◽  
Single Phase Inverter ◽  
Intelligent Power Module ◽  
The Stability

According to the requirement of a missile’s power supply, a 150V/50Hz high-quality single-phase inverter has been developed, and the CPU is TMS320LF2407A, and the main circuit is full-bridge inverter intelligent power module (IPM), and SPWM control method has been used too. The stability and the accuracy of the output voltage of this power supply have been improved because of the use of the digital PID regulator. The results of experiments show that the power supply has the advantages of the simple-circuit, the high-quality output-waveform, the high-stability output-voltage and so on.

In-situ observation of damage evolution in polycarbonate subjected to hypervelocity impact

2019 ◽  
Author(s):  
Nobuaki Kawai ◽  
Mikio Nagano ◽  
Sunao Hasegawa ◽  
Eiichi Sato
Keyword(s):  
Real Time ◽  
Stress Wave ◽  
Damage Evolution ◽  
Impact Damage ◽  
Hypervelocity Impact ◽  
The Other ◽  
Impact Event ◽  
Real Time Imaging ◽  
The Impact ◽  
Impact Events

Abstract In the fields of space engineering and planetary science, hypervelocity impact phenomena have been studied as they relate to the space debris problem and planetary impact. With regard to hypervelocity-impact-induced damage, many studies focus on the evaluation of impact-damage geometry and morphology, for example, to construct the ballistic limit equations and/or penetrating equations for space structures, and to predict the size and shape of crater and fragments generated by planetary impact [1-4]. While the final state or late stage of an impact event are of primal interest, damage accumulation at early stages affect the overall outcome of the impact event. The understanding of hypervelocity-impact-damage processes lead to improvement of material-response models for hypervelocity impact and higher fidelity simulations of hypervelocity impact events. Under such a background, we have performed real-time imaging of hypervelocity-impact events on transparent materials to investigate the impact-damage formation and evolution processes [5-7]. In our previous work, the stress-wave-propagation behavior and damage evolution were observed by means of a transmitted light shadowgraph. In these measurements, the shape of the longitudinal-stress-wave front, crater and spall fracture were successfully visualized. On the other hand, these shadowgraph images provide little information about damage microstructure. The shadowgraph has difficulty in visualizing ramped waves, such as the release wave, and also for the shear wave which is not accompanied by the change of volumetric strain. Those play important role in initiating damage. This occurs because the intensity of the shadowgraph image depends on the second spatial derivative of the refractive index. In this study, we try two types of real-time imaging of impact events. One is imaging by using scattered light on the impacted target to visualize the microstructure of the impact-induced damage, the other is a shadowgraph using polarized light to visualize propagation of the impact-induced stress field.

The Impact of Filtering on Sea and Air Operations

1983 ◽  
Vol 36 (1) ◽  
pp. 74-80
Author(s):  
M. G. Pearson
Keyword(s):  
Real Time ◽  
Kalman Filtering ◽  
The Other ◽  
Estimation Methods ◽  
Weighted Mean ◽  
Modern Approach ◽  
On Line ◽  
Computer Based ◽  
And Control ◽  
The Impact

Estimation methods and filtering techniques are nowadays an integral part of any computer-based navigation system. The purpose of these techniques is to provide an estimate of required variables which is sufficiently accurate for real-time command and control purposes. Repeatability, which is important for so many applications, is deemed to be a by-product of the estimation process. For this requirement it is not strictly necessary for the process to be accurate, it is sufficient if it is only consistent; these are closely linked but one does not imply the other. The modern approach is to minimize the variance of the noisy observations or the sum of the squares of the residuals, and the methods available for doing this are increasingly refined. The impression given in the literature (and it is extensive) is that data processing can somehow compensate for the shortcomings of the basic sensors with respect to the operation being considered. Within certain limits this is true, but the real reason for the sudden surge of Kalman filtering for real-time on-line applications was the relative simplicity of the computational process. In a way, Kalman filtering has done for estimation theory what the Fast Fourier Transform has done for spectral analysis.The concept is simple enough to state. It consists of combining two independent estimates of a variable to form a weighted mean. One of these estimates is a forecast and the other is the current measurement.

scholarly journals WHEN TIME FLIES: STATE AND TRAIT BOREDOM, TIME PERCEPTION, AND HEDONIC TASK APPRAISALS

2021 ◽  
Vol 14 (1) ◽  
pp. 150-174
Author(s):  
Emily R. Weiss ◽  
McWelling Todman ◽  
Özge Pazar ◽  
Sophia Mullens ◽  
Kristin Maurer ◽  
...  
Keyword(s):  
Real Time ◽  
Empirical Research ◽  
Time Perception ◽  
Positive Association ◽  
The Other ◽  
Future Research ◽  
Impact Time ◽  
Trait Boredom ◽  
State Boredom ◽  
The Impact

An abundance of empirical research has established that a robust, positive association exists between feelings of boredom and the illusion of temporal slowing. Although state and trait forms of boredom are distinct constructs, the way these variables interact with one another to impact time perception is unknown. To further explore the association between boredom and time perception, a modified replication of a study that examined the impact of discrepancies between expected and perceived time progression on hedonic appraisals was conducted. The paradigm was extended through the inclusion of validated measures of trait and recent state boredom. Seventy-two participants (N = 72, aged 18-52, M = 23.06, SD = 5.73) were led to believe that they would perform an intrinsically unengaging task for 5 (Time Drags), 10 (Real Time), or 15 minutes (Time Flies). Consistent with previous findings, participants in the Time Drags condition reported time as progressing significantly slower than participants in the other two conditions. Moreover, participants in the Time Drags condition rated the task as significantly more aversive than did participants in the Time Flies condition. This association remained significant even when controlling for levels of trait and recent state boredom. However, the Real Time and Time Flies conditions did not differ from one another in terms of task ratings or perceived time progression. Implications of these findings and directions for future research are discussed.

scholarly journals Research on the Transient Characteristics of Microgrid with Pulsed Load

2015 ◽  
Vol 2015 ◽  
pp. 1-15 ◽  
Author(s):  
Jianke Li ◽  
Jinquan Wang ◽  
Ye Xu ◽  
Haitao Zhang ◽  
Chunming Wang ◽  
...  
Keyword(s):  
Duty Cycle ◽  
Peak Power ◽  
Average Power ◽  
Synchronous Generator ◽  
System Dynamic ◽  
Cycle Period ◽  
Resistive Load ◽  
Insulated Gate Bipolar Transistor ◽  
Deviation Rate ◽  
The Impact

Unlike traditional load, pulsed load typically features small average power and large peak power. In this paper, the mathematic models of microgrid consisting of synchronous generator and pulsed load are established. Average Magnitude Difference Compensate Function (AMDCF) is proposed to calculate the frequency of synchronous generator, and, based on AMDCF, relative deviation rate (RDR) which characterizes the impact of pulsed load on the AC side of grid is firstly defined and this paper describes calculation process in detail. Insulated Gate Bipolar Transistor (IGBT) is used as DC switch to control the on/off state of resistive load for simulating pulsed load, the period and duty-cycle of the pulsed load are simulated by setting the gate signal of IGBT, and the peak power of the pulsed load is simulated by setting the resistance. The system dynamic characteristics under pulsed load are analyzed in detail, and the influence of duty-cycle, period, peak power, and filter capacitance of the pulsed load on system dynamic indicators is studied and validated experimentally.

A New Duty Cycle Control Strategy for Digital Constant-Current LED Drive Based on Buck-Boost Topology

2013 ◽  
Vol 392 ◽  
pp. 676-681
Author(s):  
Lin Bo Wang ◽  
Hong Kun He ◽  
Lei Shi ◽  
Jin Jin Yang ◽  
Qian Ni Feng
Keyword(s):  
Duty Cycle ◽  
Output Voltage ◽  
High Speed ◽  
Control Method ◽  
Visible Light Communication ◽  
Input Voltage ◽  
Current Control ◽  
Constant Current ◽  
Output Current ◽  
Embedded Chip

This paper proposes a new digital constant-current control method for high-power LED drive based on buck-boost topology. In this control system, buck-boost topology is used as the power conversion. The output voltage can be either higher or lower than the input voltage in buck-boost topology. Therefore, it solves the problem that in the buck topology the input voltage is required to be always higher than the output voltage. Furthermore, according to the input and output parameters, the duty cycle data which are used to maintain output current constant can be calculated in advance, and stored in the embedded chip. Thus, it can reduce the calculation of the embedded chip and solves the problem that the existing digital constant-current controllers need the high-speed analog-to-digital converter. In addition, in order to reduce the error generated in above calculation, the double threshold feedback circuit is used to fine-tune the duty cycle and makes the output current more steady and accurate. Meanwhile, due to adopting full-digital control, the brightness and flicker frequency of load LED can be conveniently regulated by modifying the system firmware. Therefore, this method can apply to the device of illumination, lighting decoration, visible light communication and so on.

Modernism, Empiricism, and Rationalism

2016 ◽  
Vol 46 (1) ◽  
pp. 38-47
Author(s):  
Geoffrey Squires
Keyword(s):  
Twentieth Century ◽  
The Other ◽  
Modern Poetry ◽  
Philosophical Perspective ◽  
Irish Poetry ◽  
Dimensional Spectrum ◽  
Culture History ◽  
The World ◽  
The Impact ◽  
Rule Out

Modernism is usually defined historically as the composite movement at the beginning of the twentieth century which led to a radical break with what had gone before in literature and the other arts. Given the problems of the continuing use of the concept to cover subsequent writing, this essay proposes an alternative, philosophical perspective which explores the impact of rationalism (what we bring to the world) on the prevailing empiricism (what we take from the world) of modern poetry, which leads to a concern with consciousness rather than experience. This in turn involves a re-conceptualisation of the lyric or narrative I, of language itself as a phenomenon, and of other poetic themes such as nature, culture, history, and art. Against the background of the dominant empiricism of modern Irish poetry as presented in Crotty's anthology, the essay explores these ideas in terms of a small number of poets who may be considered modernist in various ways. This does not rule out modernist elements in some other poets and the initial distinction between a poetics of experience and one of consciousness is better seen as a multi-dimensional spectrum that requires further, more detailed analysis than is possible here.

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