Damping Network Research Articles

Novel integrated coupled inductor boost with RL parallel damping network for improving dynamic response

Novel integrated coupled inductor boost with RL parallel damping network for improving dynamic response

Enhanced Three-Phase AC Common-Mode Filter With Optimized Damping Network for VFDs

This paper presents a highly integrated three-phase AC common-mode (CM) filter with optimized damping network for low voltage, high current motor drive applications. Simplified reduced order models and design guidelines for tuning of RLC parameters are proposed. A single turn AC-CM inductor can be realized using the proposed circuit and design technique, due to lower magnetizing inductance requirement. The RC network is found to provide 50% higher attenuation to peak CM currents compared to a conventional AC inductor alone. At the same time, the peak-volt-second across the CM inductor can be reduced, which is critical for weight sensitive applications. A trade-off between AC-CM inductance and damping resistor losses is evaluated to extract the desired optimal RLC parameters of the AC filter. The proposed circuit is designed and verified with high power <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">SiC</i> -based Three Level T-type inverter.

Linear feature projective geometric damped convolutional deep belief network for indoor floor planning

Wireless localization or positioning is essential for delivering location-based services for designing location tracking systems. Traditional indoor floor planning system employs wireless signals for accurate position estimation. But these positioning schemes failed to perform position estimation effectively and accurately through many obstacles or objects. The novel technique called Linear Features Projective Geometric Damped Convolutional Deep Belief Network (LFPGDCDBN) is introduced to improve the position estimation accuracy with minimum error. The proposed LFPGDCDBN technique includes two major processes namely dimensionality reduction and position estimation. First, the dimensionality reduction process is performed by projecting the principle features using Linear Helmert–Wolf blocked Sammon projection. After the feature selection, Geometric Levenberg–Marquardt Convolutional deep belief network is employed to estimate the position of the devices with higher accuracy and minimum error. The Convolutional deep belief network uses the triangulation geometric method to identify the position of the device in an indoor positioning system. Then the Levenberg–Marquardt function is a Damped least square method to minimize the squares of the deviations between the expected and observed results at the output unit. As a result, the LFPGDCDBN increases the positioning accuracy and minimizes the error rate. Experimental MATLAB assessment is carried out with various factors such as computational time, Computational space, positioning accuracy, and positing error. The experimental results and discussion indicate that the proposed LFPGDCDBN provides improved performance in terms of achieving higher positioning accuracy and minimum error as well as computational time when compared to the existing methods. The experimental results and discussion indicate that the proposed LFPGDCDBN increases the positioning accuracy by 47% and computational time, computational complexity, and reduces the positioning error by 45%, 29%, and 74% as compared to state-of-the-art works.

Decay-rate-constrained design of vibration damping network by a non-convex approach

Decay-rate-constrained design of vibration damping network by a non-convex approach

Decay-rate-constrained design of vibration damping network by a non-convex approach

Decay-rate-constrained design of vibration damping network by a non-convex approach

Shunt power factor correction devices for damping of harmonic resonance in industrial power systems

THE PURPOSE. Harmonic resonance has become a serious problem of shunt capacitor banks for reactive power and voltage support. Effective solution to damp out the capacitor-caused resonance is the series connection of capacitor bank with harmonic damping network. This paper presents a general design method for shunt capacitive compensating units with damping networks. The damping unit is designed in such a way that it provides harmonic filtering and adequate damping of the transient oscillations. METHODS. The method was developed for designing damping network in the form of ladder LC-two-port. The design is based on minimization of voltage total harmonic distortion (VTHD) in the point of common coupling. Normalized element parameters of the different order damping networks have been determined. RESULTS. Comparative study of transient behavior of shunt capacitive compensating units with damping networks illustrate the effectiveness of the propose structure. It has been observed that there is a significant reduction of transient overvoltage in switching of capacitor bank with damping network. CONCLUSION. This paper presents a new design method for capacitive compensating units with damping networks for industrial power systems with powerful nonlinear loads. The paper illustrates superior performance characteristics of proposed shunt capacitive compensating units by computer simulations.

A New Method to Restrain Schuler Periodic Oscillation in Inertial Navigation System Based on Normal Time–Frequency Transform

The pure inertial navigation system (INS) contains three inherent periodic oscillations, namely, Schuler periodic oscillation (84.4 min), Foucault periodic oscillation and Earth periodic oscillation (24 h), which can decrease the navigation accuracy, especially in long-term and low-velocity applications, such as ships and submarines. This paper applies the inaction method (IM) to restrain Schuler periodic oscillation. Compared to external damping network technology and integrated navigation technology, the IM is more independent, as it does not require auxiliary reference information. The IM is based on the so-called normal time-frequency transform (NTFT), and its uniqueness lies in recognizing and extracting instantaneous amplitude, frequency and phase from a harmonic/quasi-harmonic signal directly and exactly. In this paper, simulation data and experimental data are analyzed, and both show that the IM is effective. Moreover, the calculation results show that IM has wider applicability and higher stability than internal damping network technology and bandpass filtering. Compared to pure INS, the root mean square (RMS) of the velocity error decreases significantly; the RMSs of the latitude and longitude errors decrease as well. The IM can restrain Schuler periodic oscillation, and Foucault periodic oscillation is also restrained. However, the IM has no effect on the divergence of longitude error, and the edge effect is a drawback that needs to be addressed in the future.

A model integrating multiple processes of synchronization and coherence for information instantiation within a cortical area

What is the form of dynamic, e.g., sensory, information in the mammalian cortex? Information in the cortex is modeled as a coherence map of a mixed chimera state of synchronous, phasic, and disordered minicolumns. The theoretical model is built on neurophysiological evidence. Complex spatiotemporal information is instantiated through a system of interacting biological processes that generate a synchronized cortical area, a coherent aperture. Minicolumn elements are grouped in macrocolumns in an array analogous to a phased-array radar, modeled as an aperture, a “hole through which radiant energy flows.” Coherence maps in a cortical area transform inputs from multiple sources into outputs to multiple targets, while reducing complexity and entropy. Coherent apertures can assume extremely large numbers of different information states as coherence maps, which can be communicated among apertures with corresponding very large bandwidths. The coherent aperture model incorporates considerable reported research, integrating five conceptually and mathematically independent processes: 1) a damped Kuramoto network model, 2) a pumped area field potential, 3) the gating of nearly coincident spikes, 4) the coherence of activity across cortical lamina, and 5) complex information formed through functions in macrocolumns. Biological processes and their interactions are described in equations and a functional circuit such that the mathematical pieces can be assembled the same way the neurophysiological ones are. The model can be conceptually convolved over the specifics of local cortical areas within and across species. A coherent aperture becomes a node in a graph of cortical areas with a corresponding distribution of information.

Bandgap coupling effects between hybrid nonlinear synchronized switch damping and linear two-order resonant bandgaps in piezoelectric meta-structures

To study the bandgap coupling mechanism between nonlinear synchronized switch damping and multi-order linear resonant bandgaps, this research investigates the bandgap coupling effects between nonlinear synchronized switch damping and two-order linear resonant bandgaps in a piezoelectric meta-structure. Specifically, a piezoelectric meta-structure with hybrid nonlinear synchronized switch damping and linear two-order linear resonant electrical networks is proposed. Based on the theoretical modeling of the proposed structure, band structure and vibration transmittance performance are investigated in detail. Results showed that bandgap coupling can produce a trade-off with the advantages of both nonlinear and two-order linear resonant bandgaps. The new bandgap can not only realize broadband wave attenuation performance but also greatly enhance the attenuation in selected frequency bands, which provides a new method to manipulate elastic waves in a diversified way.

Information geometric inequalities of chemical thermodynamics

We study a connection between chemical thermodynamics and information geometry. We clarify a relation between the Gibbs free energy of an ideal dilute solution and an information-geometric quantity called an $f$-divergence. From this relation, we derive information-geometric inequalities that give a speed limit for a changing rate of the Gibbs free energy and a general bound of chemical fluctuations. These information-geometric inequalities can be regarded as generalizations of the Cram\'{e}r--Rao inequality for chemical reaction networks described by rate equations, where unnormalized concentration distributions are of importance rather than probability distributions. They hold true for damped oscillatory reaction networks and systems where the total concentration is not conserved so that the distribution cannot be normalized. We also formulate a trade-off relation between speed and time on a manifold of concentration distribution by using the geometrical structure induced by the $f$-divergence. Our results apply to both closed and open chemical reaction networks, thus they are widely useful for thermodynamic analysis of chemical systems from the viewpoint of information geometry.

A novel soft sensor based warning system for hazardous ground-level ozone using advanced damped least squares neural network

Estimation of hazardous air pollutants in the urban environment for maintaining public safety is a significant concern to mankind. In this paper, we have developed an efficient air quality warning system based on a low-cost and robust ground-level ozone soft sensor. The soft sensor was developed based on a novel technique of damped least squares neural network (DLSNN) with greedy backward elimination (GBE) for the estimation of hazardous ground-level ozone. Only three meteorological factors were used as input variables in the estimation of ground-level ozone and we have used weighted k-nearest neighbors (WkNN) classifier with fast response for development of air quality warning system. We have chosen the urban areas of Taiwan for this study and have analyzed seasonal variations in the ground-level ozone concentration of various cities in Taiwan as part of this work. Moreover, descriptive statistics and linear dependence of ozone concentration based on Spearman correlation coefficient, Kendall's tau coefficient, and Pearson coefficient are calculated. The proposed DLSNN/GBE method exhibited excellent performance resulting in very low mean square error (MSE), mean absolute error (MAE), and high coefficient of determination (R2) compared to other traditional approaches in ozone concentration estimation. We have achieved a good fit in the determination of ozone concentration from meteorological features of atmosphere. Moreover, the excellent performance of proposed urban air quality warning system was evident from the good F1-score value of 0.952 achieved by the WkNN classifier.

Optimized auxiliary oscillators for the simulation of general open quantum systems

A method for the systematic construction of few-body damped harmonic oscillator networks accurately reproducing the effect of general bosonic environments in open quantum systems is presented. Under the sole assumptions of a Gaussian environment and regardless of the system coupled to it, an algorithm to determine the parameters of an equivalent set of interacting damped oscillators obeying a Markovian quantum master equation is introduced. By choosing a suitable coupling to the system and minimizing an appropriate distance between the two-time correlation function of this effective bath and that of the target environment, the error induced in the reduced dynamics of the system is brought under rigorous control. The interactions among the effective modes provide remarkable flexibility in replicating non-Markovian effects on the system even with a small number of oscillators, and the resulting Lindblad equation may therefore be integrated at a very reasonable computational cost using standard methods for Markovian problems, even in strongly non-perturbative coupling regimes and at arbitrary temperatures including zero. We apply the method to an exactly solvable problem in order to demonstrate its accuracy, and present a study based on current research in the context of coherent transport in biological aggregates as a more realistic example of its use; performance and versatility are highlighted, and theoretical and numerical advantages over existing methods, as well as possible future improvements, are discussed.

Dynamic enhancement of interleaved step-up/step-down DC–DC converters using passive damping networks

In this paper, a passive damping network between two stages of a cascaded DC–DC boost/buck interleaved converter was proposed to enhance the dynamic behavior. By this damping network, the right-half plane zeros in converter’s transfer function are sufficiently departed from the left half-plane, which leads to more damped transient behavior. A frequency analysis illustrated the dynamic enhancement in the proposed converter. To validate the theoretical model under different related circumstances, experimental results are presented through implementing a prototype setup.

DC bus stabilization using passive damping network in distributed power system with constant power load

In distributed power system (DPS), the stability performance is always associated with the behaviour of constant power load (CPL). Since DPS large complex system build up from many power electronic converters, the DC bus of the system becomes unstable due to the strenuous action from power converters. When these converters tightly regulated, it behaves as constant power load and exhibit negative incremental input impedance which becomes the main reason in stability degradation of DPS. In this paper, four passive damping network topologies was proposed to reduce the DC bus instability. The best damping performance of the topologies was chosen and analysed using MATLAB/Simulink. The DC bus performances was studied in four cases which are damping behavior due to CPL power level, CPL disconnection, effects of filter and damping capacitor, and effects of filter cut-off frequency. Simulation results obtained shows that the DC bus was successfully stabilized and the resonance damped when passive damper installed. An experimental hardware tests was conducted to verify the proposed damping method and the results were compared with the simulated output waveforms. The analysis results in overshoot, settling time and steady state error of bus voltage shows system improvement with the proposed damper network.

A Novel Damping Method for Strapdown Inertial Navigation System

There are periodic oscillation errors in the strapdown inertial navigation system (SINS) when it works in pure inertial navigation mode. It seriously restricts the navigation accuracy of the system. In order to improve the accuracy of the system, the traditional idea of the external horizontal damping in the stabilized inertial navigation system is introduced into SINS. We find that they are equivalent through comparing the damping network of the stabilized inertial navigation system with the compass alignment network. According to the equivalence, the external horizontal damping network of SINS is designed. And the difference between the velocity of the system itself and the velocity of the electromagnetic log are utilized to damp the periodic oscillation. At the same time, a horizontal damping algorithm based on the external velocity is proposed on the basis of the external horizontal damping idea. The effectiveness of the algorithm is verified by the static base of the three-axis turntable, the swing base experiment, and the vehicle simulation experiment. The experiment shows that the external damping network designed in this paper can suppress the system Schuler periodic oscillation error and improve the accuracy of the system.

About dielectric relaxation in highly cross-linked poly(ethylene oxide)

The effect of lithium salt on dynamics in highly cross-linked poly(ethylene oxide) (PEO) has been investigated. The elaboration uses results of dielectric relaxation studies. It turns out that competition of electric and structural relaxation coins conductivity mechanism. Neat cross-linked PEO with low mesh size can be transferred in super-cooled liquid state. Then, cross-linked PEO behaves like a hydrogen-bonded liquid since crystallization is strongly suppressed. As a result, one observes slow Debye-like relaxation at low temperature. It disappears after addition of salt since interaction of salt with polymer chains is stronger than the hydrogen-bonded network in the neat polymer. Analysis of tangent-loss spectra shows: Particle density governing dc conductivity does not depend on temperature at low concentration of added salt. It increases with temperature for neat cross-linked PEO and PEO loaded with sufficiently high concentration of salt. Prevention of crystallization requires a tight network of cross-links. Scaled representations of relevant impedance data for neat cross-linked PEO over extended ranges of frequency and temperature reveal that electric and structural relaxations are independent of temperature to good approximation at low and high frequency. There is a range of damped network oscillations, sandwiched between these limits, where relaxation becomes dependent on temperature. This range lessens with temperature. It does not occur at all in salt-comprising cross-linked PEO.

An Ultra-Wideband Fast Frequency Ramp Synthesizer at 60 GHz With Low Noise Using a New Loop Gain Compensation Technique

Phase-locked loops (PLLs) for ultra-wideband, low noise, and linear frequency ramp synthesis exhibit a wide variation of the loop gain, if no compensation method is applied. This impairs the performance of the PLL and the corresponding microwave measurement systems. To overcome the disadvantages of existing compensation techniques, we present a new compensation method based on a phase-frequency detector gain modulation. This offers low hardware complexity and avoids additional noise. Furthermore, we present an ultra-wideband, low noise monolithic microwave-integrated circuit for 60-GHz PLLs. Based on this, a 60-GHz frequency synthesizer with a modulation bandwidth of 22 GHz and a jitter of less than 79 fs at the center frequency are realized. The new compensation technique reduces the variation of the loop gain from 14.2:1 to 1.67:1 and is compared with an existing compensation technique utilizing a voltage-dependent damping network, which reduces the variation of the loop gain to 1.78:1. Due to the reduction of the variation of the loop gain, the maximum ramp slope increases from 22 GHz/2.9 ms up to 22 GHz/0.35 ms. In addition, the time jitter of the output signal of the PLL decreases by up to 18%. Furthermore, the PLL performance is constant in the temperature range from 0 °C to 70 °C.

Passive Damper Network in a Simple DC Distribution Power System

Distributed power system (DPS) distributes power amongst processing units such as power electronics converters with DC system. Due to the increasing usage of power converters in DPS system, the system becomes unstable and the converter tends to draw constant power needed by the load of the system. Constant power load (CPL) characteristic has negative input impedance that could produce instability problems in the DC bus system. Passive damping network which consists of series RC damping circuit was connected in parallel to the DC bus system with the purpose to reduce the instability. The passive damper was designed, simulated with MATLAB/Simulink and verified experimentally with different values of CPL power levels and input voltage changes. The obtained simulation results show that simple DC system with constant power load was successfully stabilized by the installation of the passive damping network. The experimental set up was also conducted to validate of the proposed technique, and the obtained results were in excellent agreement with the theoretical parts of the project.

Dynamic Performance Improvement of Diode–capacitor-Based High Step-up DC–DC Converter Through Right-Half-Plane Zero Elimination

Diode–capacitor-based dc–dc converters provide a simple and low cost solution for high step-up voltage regulation in solar and fuel cell generation. Transient modeling analysis reveals their worse influence of nonlinear and nonminimum-phase system characteristic due to right-half-plane (RHP) zero, especially in high voltage gain application. However, the process of energy transfer for diode–capacitor-based dc–dc converter is different from basic dc–dc converter. Based on the unique feature, this paper proposes an improved main circuit structure with parallel connection of resistive–capacitive damping network across the intermediate capacitor to achieve good dynamic performance. By optimal parameter design according to Routh–Hurtwitz criterion, all the RHP zeros in the transfer function of control-to-output voltage are eliminated completely. Then, by the case of diode–capacitor-based boost converter, the adaptive PI controller is designed to deal with nonlinear characteristic of voltage gain. It gets good dynamic performance under wide range output voltage. All the theoretical findings and design approaches are verified by simulation and experiment results. The existing diode–capacitor-based high step-up dc–dc converters with slight main circuit modification are more promising in renewable energy application.

An Adaptive Damping Network Designed for Strapdown Fiber Optic Gyrocompass System for Ships.

The strapdown fiber optic gyrocompass (strapdown FOGC) system for ships primarily works on external horizontal damping and undamping statuses. When there are large sea condition changes, the system will switch frequently between the external horizontal damping status and the undamping status. This means that the system is always in an adjustment status and influences the dynamic accuracy of the system. Aiming at the limitations of the conventional damping method, a new design idea is proposed, where the adaptive control method is used to design the horizontal damping network of the strapdown FOGC system. According to the size of acceleration, the parameters of the damping network are changed to make the system error caused by the ship’s maneuvering to a minimum. Furthermore, the jump in damping coefficient was transformed into gradual change to make a smooth system status switch. The adaptive damping network was applied for strapdown FOGC under the static and dynamic condition, and its performance was compared with the conventional damping, and undamping means. Experimental results showed that the adaptive damping network was effective in improving the dynamic performance of the strapdown FOGC.