scholarly journals Piezoelectric resonant shunt enhancement by negative capacitances: Optimisation, performance and resonance cancellation

2018 ◽  
Vol 29 (12) ◽  
pp. 2581-2606 ◽  
Author(s):  
Marta Berardengo ◽  
Stefano Manzoni ◽  
Olivier Thomas ◽  
Marcello Vanali
Keyword(s):  
Electrical Circuit ◽  
Practical Implementation ◽  
Mathematical Treatment ◽  
Negative Capacitance ◽  
Control Performance ◽  
Shunt Damping ◽  
Stability Issues ◽  
Resonant Shunt ◽  
Theoretical Results ◽  
Shunt Impedance

This article addresses piezoelectric shunt damping through a resonant shunt associated with negative capacitances. The main objective of this article is to provide guidelines for choosing the best electrical circuit layout in terms of control performance and possible stability issues. This article proposes general analytical formulations for the tuning/optimisation of the electrical shunt impedance and for the prediction of the attenuation performance. These formulations are demonstrated to be valid for all the possible configurations of the negative capacitances. It is demonstrated that the behaviour of the different shunt circuits can indeed be described by a common mathematical treatment. Moreover, the use of two negative capacitances together is shown to provide benefits compared to traditional layouts based on a single negative capacitance. The mentioned advantages relate to both stability and attenuation performance. The use of a resonant shunt with the addition of negative capacitances is finally proven to provide enough attenuation to even cancel eigenfrequency peaks in some cases. This article also analyses the main issues arising from the practical implementation of the negative capacitances. Finally, the theoretical results are validated through experiments conducted on a cantilever beam coupled to two piezoelectric patches.

scholarly journals Improved shunt damping with two negative capacitances: An efficient alternative to resonant shunt

2016 ◽  
Vol 28 (16) ◽  
pp. 2222-2238 ◽  
Author(s):  
M Berardengo ◽  
O Thomas ◽  
C Giraud-Audine ◽  
S Manzoni
Keyword(s):  
Electrical Circuit ◽  
Negative Capacitance ◽  
Stability Margins ◽  
Experimental Campaign ◽  
Modal Damping ◽  
Vibration Attenuation ◽  
Efficient Alternative ◽  
Control Capability ◽  
Shunt Damping ◽  
Resonant Shunt

This paper deals with piezoelectric shunt damping enhanced with negative capacitances. A novel electrical circuit layout is addressed, based on the use of two negative capacitances. It is shown that the shunt performances, in terms of vibration reduction and stability margins, are increased as compared with the classical single negative capacitance layouts. Then, the article focuses on the comparison of a simple resistive shunt, enhanced by a pair of negative capacitances, with a classical resonant shunt. It is shown that the newly proposed enhanced resistive shunt can show equivalent performances in terms of vibration attenuation than the resonant shunt, with at the same time an increased robustness to frequency detuning, in the case of mono-modal damping. The broadband control capability of the resistive shunt coupled to the new negative capacitance layout is also evidenced. The main part of the work is analytical, and then the model is validated by an extensive experimental campaign at the end of the paper.

Guidelines for the layout and tuning of piezoelectric resonant shunt with negative capacitances in terms of dynamic compliance, mobility and accelerance

2021 ◽  
pp. 1045389X2098699
Author(s):  
Marta Berardengo ◽  
Stefano Manzoni ◽  
Olivier Thomas ◽  
Marcello Vanali
Keyword(s):  
Dynamic Compliance ◽  
Practical Implementation ◽  
Experimental Campaign ◽  
Vibration Attenuation ◽  
Circuit Components ◽  
Resonant Shunt ◽  
Theoretical Results ◽  
Shunt Impedance ◽  
Piezoelectric Shunt ◽  
Shunt Circuit

This paper addresses the vibration attenuation provided by the resonant piezoelectric shunt enhanced by means of negative capacitances. The shunt impedance is composed by one or two negative capacitances, a resistance and an inductance. It is shown that closed analytical formulations, common to all the possible connections of the negative capacitances, can be derived for the tuning of the circuit components and for the prediction of the attenuation in terms of dynamic compliance, mobility and accelerance. The paper also compares the attenuation performance provided by the two possible layouts for the electrical link between the resistance and the inductance, that are series and parallel. Furthermore, this work evidences which shunt configurations offer advantages in terms of practical implementation and the benefits provided by the use of negative capacitances in the shunt circuit. In the last part of the paper, guidelines for the use of resonant shunt are given to the reader and, finally, the theoretical results are validated by means of an experimental campaign showing that it is possible to cancel the resonance on which the resonant shunt is targeted.

scholarly journals A New Electrical Circuit With Negative Capacitances to Enhance Resistive Shunt Damping

2015 ◽  
Author(s):  
Marta Berardengo ◽  
Stefano Manzoni ◽  
Olivier Thomas ◽  
Christophe Giraud-Audine
Keyword(s):  
Electromechanical Coupling ◽  
Short Circuit ◽  
Electromechanical Coupling Factor ◽  
Coupling Factor ◽  
Open Circuit ◽  
Electrical Circuit ◽  
Structural Vibration ◽  
Electrical Network ◽  
Negative Capacitance ◽  
Shunt Damping

This article proposes a new layout of electrical network based on two negative capacitance circuits, aimed at increasing the performances of a traditional resistive piezoelectric shunt for structural vibration reduction. It is equivalent to artificially increase the modal electromechanical coupling factor of the electromechanical structure by both decreasing the short-circuit natural frequencies and increasing the open-circuit ones. This leads to higher values of the modal electromechanical coupling factor with respect to simple negative capacitance configurations, when the same margin from stability is considered. This technique is shown to be powerful in enhancing the control performance when associated to a simple resistive shunt, usually avoided because of its poor performances.

scholarly journals Practical Implementation of Adaptive SRF-PLL for Three-Phase Inverters Based on Sensitivity Function and Real-Time Grid-Impedance Measurements

Energies ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1173 ◽  
Author(s):  
Roni Luhtala ◽  
Henrik Alenius ◽  
Tomi Roinila
Keyword(s):  
Real Time ◽  
Power Quality ◽  
Binary Sequence ◽  
Wind Farms ◽  
Negative Resistance ◽  
Dynamic Responses ◽  
Practical Implementation ◽  
Control Performance ◽  
Grid Impedance ◽  
Stability Issues

Rapidly increasing demand for renewable energy has created a need for the photovoltaic and wind farms to be placed in various locations that have diverse and possibly time-variant grid conditions. A mismatch between the grid impedance and output admittance of an inverter causes impedance-based stability issues, which appear as power quality problems and poor transient performance. Grid synchronization with phase-locked loop (PLL) introduces a negative-resistance-like behavior to inverter output admittance. High control bandwidth of the PLL makes the system sensitive to impedance-based stability issues when the inverter is connected to a weak grid that has high impedance. However, very conservative tunings lead to overly damped dynamic responses in strong grids, where the control performance and power quality can be improved by applying higher PLL control bandwidths. Continuous evaluation of grid conditions makes it possible to avoid the risk of instability and poor dynamic responses, as the inverter output admittance can be re-shaped online to continuously match the grid conditions. The present work proposes method for adaptive control of the PLL based on the real-time measurements of the grid impedance, applying pseudo-random binary sequence (PRBS) injections. The method limits the PLL bandwidth in weak grids to avoid stability issues and increases the control bandwidth in strong grids to improve voltage-tracking, and thus overall control performance. The method is verified through simulations and experimental laboratory tests in a kW-scale system. The results show that optimizing the PLL bandwidth with respect to the grid conditions is highly beneficial for system performance and stability.

Experimental Implementation of Negative Impedance Shunts on Periodic Structures

2009 ◽  
Author(s):  
Benjamin Beck ◽  
Kenneth A. Cunefare ◽  
Massimo Ruzzene ◽  
Manuel Collet
Keyword(s):  
Periodic Structures ◽  
Experimental Results ◽  
Periodic Array ◽  
Negative Capacitance ◽  
Experimental Implementation ◽  
Theoretical Predictions ◽  
Shunt Damping

Shunt damping of structures has been heavily researched, both passively and actively. Negative capacitance shunts actively control vibration on a structure and have been shown to obtain significant broadband suppression. The use of smaller piezoelectric patches, implemented in a periodic array, can alter the behavior of the control. Assorted shunt arrangements as well as circuit configurations will be investigated. Experimental results will be compared to theoretical predictions of shunt performance.

scholarly journals An Equivalent Circuit Analysis and Suspension Characteristics of AC Magnetic Suspension Using Magnetic Resonant Coupling

Actuators ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 52
Author(s):  
Arifur Rahman ◽  
Takeshi Mizuno ◽  
Masaya Takasaki ◽  
Yuji Ishino
Keyword(s):  
Electrical Circuit ◽  
Magnetic Suspension ◽  
The Self ◽  
Wireless Power ◽  
Equivalent Circuit Analysis ◽  
Resonant Coupling ◽  
Secondary Current ◽  
Experimental Apparatus ◽  
Primary Current ◽  
Theoretical Results

The fundamental characteristics and performances of alternating current (AC) magnetic suspension using magnetic resonant coupling are studied analytically and experimentally. Nowadays, wireless power transfer to the suspended object is required during non-contact suspension in some applications. Therefore, magnetic resonant coupling has been introduced for AC magnetic suspension to achieve self-stabilizing magnetic suspension and energy transfer to the floator simultaneously. The effect of circuit parameters for developing an experimental apparatus and performances are predicted from the solution of the equivalent circuits analytically. First, an equivalent magnetic circuit is derived and analyzed to characterize the self-inductance and mutual inductance with the gap. Second, an equivalent electrical circuit is analyzed to derive the current and force equations including magnetic parameters of the circuit. The derivation of these equations is numerically solved to study the characteristics of the primary current, the secondary current, and the force with respect to the gap and the applied frequency. The comparison between theoretical and experimental results is depicted, and the reason for differences is explained. The experimental and theoretical results show that positive stiffness is possible, which is essential for achieving self-stabilization. The self-stability is confirmed by the frequency response of the suspension system to disturbance experimentally.

Application of a Negative Capacitance Circuit in Synchronized Switch Damping Techniques for Vibration Suppression

2011 ◽  
Vol 133 (4) ◽  
Author(s):  
Hongli Ji ◽  
Jinhao Qiu ◽  
Jun Cheng ◽  
Daniel Inman
Keyword(s):  
Composite Beam ◽  
Vibration Suppression ◽  
Piezoelectric Element ◽  
Single Mode ◽  
Resonant Circuit ◽  
Negative Capacitance ◽  
Control Performance ◽  
Damping Effect ◽  
Mode Control ◽  
Shunt Circuit

In the synchronized switching damping (SSD) techniques, the voltage on the piezoelectric element is switched synchronously with the vibration to be controlled using an inductive shunt circuit (SSDI). The inherent capacitance and the inductance in the shunt circuit comprise an electrically resonant circuit. In this study, a negative capacitance is used in the shunt circuit instead of an inductance in the traditional SSD technique. The voltage on the piezoelectric element can be effectively inverted although the equivalent circuit is capacitive and no resonance occurs. In order to investigate the principle of the new SSD method based on a negative capacitance (SSDNC), the variation of the voltage on the piezoelectric element and the current in the circuit are analyzed. Furthermore, the damping effect using the SSDNC is deduced, and the energy balance and stability of the new system are investigated analytically. The method is applied to the single-mode control and two-mode control of a composite beam, and its control performance was confirmed by the experimental results. For the first mode in single-mode control, the SSDNC is much more effective than SSDI. In other cases, the SSDNC is also more effective than the SSDI, although not significantly.

An adaptive negative capacitance circuit for enhanced performance and robustness of piezoelectric shunt damping

2017 ◽  
Vol 28 (19) ◽  
pp. 2633-2650 ◽  
Author(s):  
Martin Pohl
Keyword(s):  
Negative Capacitance ◽  
Electronic Components ◽  
Beam Structure ◽  
Lightweight Structures ◽  
Shunt Damping ◽  
Adaptive Circuit ◽  
Electronically Tunable ◽  
Best Fit ◽  
Piezoelectric Shunt ◽  
The Ideal

Piezoelectric shunt damping is investigated as one possible solution for improving the vibroacoustic behavior of noise-prone lightweight structures. The negative capacitance shunt circuit appears to be the best choice due to its broadband damping effect. Usually, it is built from analog electronic components, such as operational amplifiers, resistors, and capacitors. In terms of damping efficiency and the vibroacoustic behavior of the circuit, the capacitance ratio between the negative capacitance and the inherent capacitance of the piezoelectric transducer is of major concern. For laboratory setups, this ratio may be adjusted manually, but for real applications, this is not suitable due to a lack of damping or the risk of instability of the circuit. Therefore, an improved approach is presented in this article, where a concept for an adaptive negative capacitance circuit is presented. An electronically tunable resistor is used to change the value of the negative capacitance to the best fit for the present conditions. Adjustment laws for the ideal value of this resistor are derived from the transfer function of the whole circuit. Finally, a prototype board is designed and experimentally tested at a beam structure. It can be shown that the adaptive circuit allows a tighter adjustment to the edge of stability resulting in higher damping or, in the case of too high vibration amplitudes, prevents the output voltage from saturating.

scholarly journals Electronic Circuit Emuling a First-order Time-delay Differential Equation

2021 ◽  
Vol 19 (1 Jan-Jun) ◽  
Author(s):  
César Jiménez ◽  
I. Campos-Canton ◽  
L. J. Ontañón-García
Keyword(s):  
Differential Equation ◽  
Time Delay ◽  
Phase Shift ◽  
Electronic Circuit ◽  
Linear Time ◽  
Electrical Circuit ◽  
First Order ◽  
Simulation Results ◽  
Delay Differential ◽  
Theoretical Results

This article provides undergraduates a useful tool for a better understanding of the time delay eect on a electronic circuit. The time delay eect is analyzed on this paper in a rst order dierential equation. This linear time delay is associated with the amplitude of a first-order dierential equation and is responsible of three responses: one of the responses is an dierential equation type in first-order without delay, another one of the responses is a dierential equation type in second-order and nally we have the response of a harmonic oscillator.The proposed circuit is an emulator that develop the three different responses mentioned above. Simulink-Matlab software was used to implement the time delay and simulate the dierential equation. This simulation results coincide with the theoretical results. In the same manner, the experimental results match those of the theory. The electronical circuits suggested consist of three blocks: an integrator block, a phase shift block and a gain block. The electrical circuit is composed of resistors, capacitors and operational ampliers.

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