High-order Resonant Circuit Research Articles

Programmable piezoelectric meta-rings with high-order digital circuits for suppressing structural and acoustic responses

In this paper, a programmable piezoelectric meta-ring equipped with high-order digital shunting circuits is designed for vibro-acoustic control. The structural and acoustic suppressing performance of the piezoelectric meta-ring in light fluid is tunable by re-programming transfer functions implemented in micro-controller units of the digital circuits. The radiated sound due to structural vibration of the meta-ring is attenuated in multiple local-resonance bandgaps, which is realized using high-order resonant circuits designed via the pole-zero placement method. An analytical model is developed for providing physical insights into vibro-acoustic behaviors of the piezoelectric meta-ring in light fluid. The analytical results agree well with numerical ones computed with the finite element method. The effects of electrical parameters such as gain parameter and electrical damping ratio on the sound radiation suppression of elastic rings are also discussed. To verify the programmability and high-order local-resonance bandgap performance of the piezoelectric meta-ring, the vibro-acoustic control experiment is carried out in the anechoic chamber. It is found that programmable bandgaps at different target frequencies of the piezoelectric meta-ring can be generated, which effectively suppress the structural–acoustic response peaks of the meta-ring.

A programmable macro-fiber-composite meta-ring with digital shunting circuits

Representing a typical class of active metamaterials with unprecedented adaptiveness, piezoelectric metamaterials have received a lot of research efforts, but which are mostly focused on beam- and plate-types. In this research, we propose a piezoelectric meta-ring shunted with digital high-order resonant circuits, where the micro-fiber-composite (MFC) are used as the electrical-mechanical transducers. Due to the programmability of digital circuits, the bandgap behavior of the meta-ring is highly adaptive. The analytical dispersion relation of meta-ring cells is achieved with the transfer matrix method. To study dynamic response of the finite meta-ring system, we derive the six-order electrical-mechanical coupling equation, and also establish its discretized form using the assumed-mode expansion method. The finite-element simulations are performed to verify this analytical model. By homogenizing the meta-ring under the long-wavelength assumption, a simplified model is attained, so as to provide a convenient means to design the bandgaps and perform stability analysis. For the sake of implementing high-order local-resonance bandgaps, we investigate two manners based on the pole-zero placement to design digital circuits. The bandgap boundaries under these two scenarios are analytically identified. Additionally, the bandgap performance of the meta-ring is simulated, followed by a comprehensive investigation of the impacts of electrical parameters, including the gain, damping and poles-zeros. For the inversely designed digital circuits, the bifurcation phenomenon of poles of the electrical admittance is uncovered, which impacts the stability of circuits. Lastly, we build an experimental set-up of the digital MFC meta-ring. Its programmable and high-order local-resonance bandgap performance is validated experimentally.

A review of high frequency resonant DC-DC power converters: Topologies and planar magnetic technologies

With the development of high frequency resonant DC-DC power converters, the system efficiency, power density and dynamic characteristics have been significantly improved. High frequency resonant DC-DC converters have been applied in DC grid, renewable energy, transportation, aerospace, point-of-load (POL) power supply and many other fields. Under high switching frequencies, switching loss and magnetic loss are the main concerns; thus, the resonant topology and planar magnetic are two key technologies to reduce loss. This review compares different resonant topologies and analyzes the advantages and disadvantages respectively, such as LLC circuit, dual active bridge (DAB) circuit, and other high order resonant circuits. For planar magnetic components, optimal winding structures, modeling methods and integration methods are thoroughly surveyed. With corresponding topics, the opportunities and challenges in the future development are summarized, which mainly focus on the characteristics of wide bandgap devices, such as the dynamic resistance, output capacitance loss and also the integrated module. This review can be a helpful guidance when designing high frequency resonant DC-DC converters.

Load-Independent Voltage and Current Transfer Characteristics of High-Order Resonant Network in IPT System

Load-independent output characteristics of an inductive power transfer (IPT) system are of increasing interest in electric vehicle and LED lighting applications. All compensation networks in the IPT system are actually high-order resonant circuits. In a high-order resonant network, there are multiple resonant frequencies to get load-independent voltage output and current output. It is critical to analyze the resonant conditions to achieve high efficiency in both load-independent voltage output and current output modes. This paper proposed a general modeling method for arbitrary high-order resonant networks to get both the load-independent voltage and current transfer characteristics. A high-order circuit can be modeled as a combination of an LC network, a multistage T-circuit, and/or multistage $\Pi $ -circuit in series. The proposed method is verified by applying to voltage-fed double-sided inductor–capacitor–capacitor (LCC), series–series (SS), S-SP, LCC-S, and current-fed CLC-LC compensation networks in the IPT system. The MATLAB simulation and the experimental prototype of a constant voltage-fed double-sided LCC compensated IPT system with up to 3.3-kW power transfer are built. The efficiency of the double-sided LCC compensated IPT system is up to 92.9% and 90.6% when the IPT system operates at resonant frequencies that achieve constant current output and constant voltage output, respectively, which are compliance with the frequency requirement by SAE J2954 standard.

Neural Networks Based PID Control of Bidirectional Inductive Power Transfer System

Inductive power transfer (IPT) systems facilitate contactless power transfer between two sides and across an air-gap, through weak magnetic coupling. However, IPT systems constitute a high order resonant circuit and, as such, are difficult to design and control. Aiming at the control problems for bidirectional IPT system, a neural networks based proportional-integral-derivative (PID) control strategy is proposed in this paper. In the proposed neural PID method, the PID gains, $$K_{P}$$KP, $$K_{I}$$KI and $$K_{D}$$KD are treated as Gaussian potential function networks (GPFN) weights and they are adjusted using online learning algorithm. In this manner, the neural PID controller has more flexibility and capability than conventional PID controller with fixed gains. The convergence of the GPFN weights learning is guaranteed using Lyapunov method. Simulations are used to test the effective performance of the proposed controller.

Vibration and wave propagation attenuation for metamaterials by periodic piezoelectric arrays with high-order resonant circuit shunts

Beam or plate metamaterials with periodic piezoelectric arrays have attracted more and more attention in recent years for wave propagation attenuation and the corresponding vibration reduction. Conventional designs use resistive shunt (R-shunt) and resistor-inductor shunt (RL-shunt). An innovative metamaterial with a high-order resonant shunt circuit is proposed and investigated for vibration and wave propagation attenuation in this paper. The proposed high-order resonant shunt circuit can introduce two local resonances in series around the tuning frequency to broaden the attenuation bandwidth, or can create two separate resonances to achieve two separate bandgaps. Finite element modeling of the beam metamaterial with wave propagation and vibration in the transverse direction is established. Simulations have been conducted to compare the vibration attenuation performances among R-shunt, RL-shunt, and the proposed high-order shunt. An impedance-based method has been presented for the parameter design of electrical components in the proposed high-order shunt for bandgaps at two desired frequencies.

Parameter identification of bidirectional IPT system using chaotic asexual reproduction optimization

Bidirectional inductive power transfer (IPT) system facilitates contactless power transfer between two sides and across an air gap, through weak magnetic coupling. Typically, this system constitutes a high-order resonant circuit and, as such, is difficult to design and control. In this study, a novel technique for parameter identification of bidirectional IPT system is presented by using chaotic asexual reproduction optimization (CARO). The asexual reproduction optimization (ARO) is a novel kind of evolutionary-based algorithm that mathematically models the budding mechanism of asexual reproduction. The CARO employs chaotic sequence to enhance ARO’s global searching ability. The parameter identification of a bidirectional IPT system is posed as an optimization process with an objective function minimizing the errors between the estimated and measured value. The implementation of the CARO-based parameter identification technique is analyzed in detail. Simulations are used to test the robustness and generalization ability of the proposed technique.

A Generalized Steady-State Model for Bidirectional IPT Systems

Bidirectional inductive power transfer (BD-IPT) systems are high-order resonant circuits, which are complex in nature and sensitive to variations in system parameters and control variables. Consequently, modeling and design of BD-IPT systems are relatively difficult in comparison to unidirectional IPT systems. An accurate model that predicts the behavior of BD-IPT systems under different operating conditions is invaluable but yet to be reported. This paper, therefore, proposes a generalized steady-state model through which the behavior of BD-IPT systems can be accurately characterized. The proposed mathematical model is comprehensive and includes the effects of harmonics and sensitivity to variations in system parameters and control variables. Using the model, this paper investigates the behavior and sensitivity of BD-IPT systems under a range of practical operating conditions. The validity of the proposed generalized model, which is verified using the results of a 1-kW prototype system, provides a clear insight into BD-IPT systems and is expected to be useful at both design and implementation stages.

A Dynamic Multivariable State-Space Model for Bidirectional Inductive Power Transfer Systems

Bidirectional inductive power transfer (IPT) systems facilitate contactless power transfer between two sides, which are separated by an air gap, through weak magnetic coupling. Typical bidirectional IPT systems are essentially high-order resonant circuits and, therefore, difficult to both design and control without an accurate mathematical model, which is yet to be reported. This paper presents a dynamic model, which provides an accurate insight into the behavior of bidirectional IPT systems. The proposed state-space-based model is developed in a multivariable framework and mapped into frequency domain to compute the transfer function matrix of eight-order bidirectional IPT systems. The interaction between various control variables and degree of controllability of the system are analyzed from the relative gain array and singular values of the system. The validity of the proposed dynamic model is demonstrated by comparing the predicted behavior with that measured from a 1 kW prototype bidirectional IPT system under various operating conditions. Experimental results convincingly indicate that the proposed model accurately predicts the dynamical behavior of bidirectional IPT systems and can, therefore, be used as a valuable tool for transient analysis and optimum controller design.