Resonant Controller Research Articles

Coupled hysteresis and resonance control of three-degree-of-freedom tip-tilt-piston piezoelectric stage

In order to solve the coupled hysteresis and resonance problems in three-degree-of-freedom tip-tilt-piston piezoelectric stage, a coupled hysteresis model and a coupled integral resonance compensation model are designed. The inverse coupled hysteresis feedforward control combined multi-axis coupled resonance control and high-gain integral tracking controller are used to improve the tracking speed and positioning accuracy of the stage. Firstly, a kinematic model of the stage is built to translate the three-degree-of-freedom motion of the end-effector into the outputs of three piezoelectric actuators. Then, a coupled hysteresis model based on the rate-dependent Prandtl–Ishlinskii model is established and parameterized to simultaneously compensate for the hysteresis of a single piezoelectric actuator and the coupled hysteresis between multiple piezoelectric actuators. The effectiveness of the model is verified by open-loop and closed-loop inverse model feedforward control experiments. Afterwards, a coupled integral resonance compensation model is also established and parameterized to suppresses the resonance and expand the system bandwidth. Finally, the proposed controller is used to conduct tracking experiments on a composite signal, and the results show that the accuracy and speed of trajectory tracking are further improved, and the mechanical coupling between axes are significantly reduced.

Grid-Connected Inverter Grid Voltage Feedforward Control Strategy Based on Multi-Objective Constraint in Weak Grid

In weak grid, feedforward of grid voltage control is widely used to effectively suppress grid-side current distortion of inverters caused by harmonics in point of common coupling (PCC) voltage. However, due to its introduction of a positive feedback loop related to the grid impedance, it results in a significant reduction in the system phase margin. In view of this, in this paper, the output impedance of a three-phase LCL grid-connected inverter under a quasi-proportional resonant (QPR) controller is first modeled. Instead of the traditional grid voltage feedforward control strategy, a band-pass filter is added to the grid voltage feedforward channel. Secondly, a multi-objective constraint method is proposed to make improvements to the feedforward function. Then, a multi-objective constraint function is established with the constraints of base-wave current tracking performance, system stability margin, and low-frequency amplitude, and the feasibility of its function optimization design method is verified. Theoretical analysis shows that the optimized grid voltage feedforward control strategy can effectively reshape the phase characteristics of the system output impedance, which greatly broadens the adaptation range of the system to the grid impedance. Finally, the effectiveness of the proposed control strategy is verified by building a semi-physical simulation experimental platform based on RT-LAB OP4510.

Advanced vibrant controller results of an energetic framework structure

Abstract This research shows the influence of a new active controller technique on a parametrically energized cantilever beam (PECB) with a tip mass model. This article remains primarily concerned with regulating the system’s response using a novel control mechanism. This study describes a novel control mechanism called the nonlinear proportional-derivative cubic velocity feedback controller (NPDCVFC). The motivation of this article is to design a novel control algorithm in order to mitigate the nonlinear vibrations of a parametrically energized cantilever beam with a tip mass model. The proposed controller NPDCVFC incorporates nonlinearly second- and first-order filters into the system. The system is governed by one nonlinear differential equation having both quadratic and cubic nonlinearities within the parametric force. The controller’s efficiency in reducing framework vibrations, managing nonlinear bifurcations, and calming unstable motion is evaluated using numerical simulations of instantaneous vibrations. The perturbation technique is beneficial for solving the current model under the proposed worst resonance case ( Ω ˆ p = 2 ω ˆ 0 ) \text{(}{\hat{{\Omega }}}_{\text{p}}=2{\hat{{\omega }}}_{0}) . In order to choose the optimal controller, we have also added three more controller approaches to the configuration. Integral resonant control, positive position feedback, and nonlinear integral positive position feedback are the three controller approaches that are applied to the structure under consideration. We determine that the NPDCVFC as a new controller is the most effective for lowering the high vibration amplitudes. Over the investigated model, all numerical results were performed using the MATLAB 18.0 programmer software. The stability analysis and the effects of various elements on the controlled structure have been investigated. A comparison with recently published works of a comparable model has also been prepared. Experiment capacities for a PECB with a tip mass are obtainable to validate the results, and they demonstrate good agreement with analytical and numerical results.

An adjustable acoustic metamaterial cell using a magnetic membrane for tunable resonance

Acoustic metamaterials are growing in popularity for sound applications including noise control. Despite this, there remain significant challenges associated with the fabrication of these materials for the sub-100 Hz regime, because acoustic metamaterials for such frequencies typically require sub-mm scale features to control sound waves. Advances in additive manufacturing technologies have provided practical methods for rapid fabrication of acoustic metamaterials. However, there is a relatively high sensitivity of their resonant characteristics to sub-mm deviations in geometry, pushing the limits of additive manufacturing. One way of overcoming this is via active control of device resonance. Here, an acoustic metamaterial cell with adjustable resonance is demonstrated for the sub-100 Hz regime. A functionally superparamagnetic membrane—devised to facilitate the fabrication process by eliminating magnetic poling requirements—is engineered using stereolithography, and its mechanical and acoustic properties are experimentally measured using laser Doppler vibrometry and electret microphone testing, with a mathematical model developed to predict the cell response. It is demonstrated that an adjustable magnetic acoustic metamaterial can be fabricated at ultra-subwavelength dimensions (≤λ\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\le \\lambda$$\\end{document}/77.5), exhibiting adjustable resonance from 88.73 to 86.63 Hz. It is anticipated that this research will drive new innovations in adjustable metamaterials, including wider frequency ranges.

РОЗРАХУНОК РЕГУЛЮВАЛЬНИХ ХАРАКТЕРИСТИК РЕЗОНАНСНИХ ПЕРЕТВОРЮВАЧІВ МЕТОДОМ СУПЕРПОЗИЦІЇ

The work presents the calculations of the control characteristics of the full-bridge resonant converter with a series resonant LLC circuit and frequency control by two methods - the first harmonic method and the superposition method. The theoretical results were verified by the analytical-structural modeling method. The power circuit of the resonant converter for the analysis of electromagnetic processes is replaced by a linear T-shaped circuit with two series resonant RLC-circuits and equivalent generators of rectangular voltages, which simulate a transistor inverter and a diode rectifier in the quasi-continuous current mode. Analytical-structural modeling method consists in partly analytical and partly structural ways of building a numerical model of the resonant converter in the form of the simulation model in the MATLAB-Simulink environment. Linear structural links of the model are created on the basis of integral equations of circles. Non-linear links are created based on the non-linear functions and causal relationships. The structural model based on these links takes into account the nonlinearity of the elements of the power circuit of the resonant converter and is based on simpler mathematical expressions compared to the equivalent mathematical model of the resonant converter. The structural model corresponds to the idea of the resonant converter in the form of the resonant circuit with independent equivalent voltage generators and allows to adjust the magnetic coupling coefficient between the transformer windings and simulate processes with arbitrary control functions of equivalent generators. The peculiarity of the use of the superposition method for calculating the static characteristics of the resonant converter is the need to match the voltage phases of the equivalent generators of the equivalent circuit during the changes of the operating frequency or relative load voltage. The dependence of the input voltage of the rectifier, which is simulated by the second equivalent generator, on the processes of the power circuit of the real resonant converter, determines the conditions for matching (adjusting) the phases of the equivalent generators. References 30, figures 5.

A stability improvement control strategy research for LLC resonant converter with single neuron PI-I double closed loop control

LLC resonant converters are widely used in the aerospace field. However, under traditional single-loop control, LLC resonant converters are prone to instability in the face of high-power load disturbances, which fails to meet the high stability requirements of the aerospace field. In order to enhance the stability and disturbance rejection capability of the LLC resonant converter, this paper proposes a stability improvement strategy with additional resonant voltage integral control based on the generalized state-space aver-aged model of the LLC resonant converter. By combining eigenvalue sensitivity analysis and eigenvalue analysis theory, the system stability is further optimized. To achieve control parameter adaptive adjustment, a single neuron algorithm is introduced, resulting in an LLC resonant converter with a single neuron PI-I double closed-loop control. Simulation results indicate that the proposed LLC resonant converter with single neuron PI-I double closed-loop control exhibits improved stability compared to the LLC resonant converter under traditional single-loop control.

Research on Inverter Control Strategy Based on FPGA

Abstract This study adopts a composite repetitive controller strategy in a three-phase four-wire circuit, combining proportional resonance and repetitive control, which effectively suppresses harmonics and improves system performance. At higher switching frequencies, FPGA is used to achieve efficient control to ensure system stability and performance. This research provides new ideas for improving the performance of on-board inverters, especially in terms of high-speed control, nonlinear load and harmonic processing. SiC devices and composite control strategies provide more sustainable solutions for future rail transit systems.

Parametric Resonance Control of Flexible Manipulator Based on Saturation and Quadratic Nonlinearity Enhancement

Parametric Resonance Control of Flexible Manipulator Based on Saturation and Quadratic Nonlinearity Enhancement

Optimal hybrid resonant current controller for microgrids connected to an unbalanced IEEE test distribution network

Microgrids (MGs) based on renewable energies have emerged as a proficient strategy for tackling power quality issues in conventional distribution networks. Nonetheless, MG systems require a suitable control scheme to supply energy optimally towards the electrical grid. This paper presents an innovative framework for designing hybrid Proportional-Resonant (PR) controllers with Linear Quadratic Regulators (LQR), PR+LQR, which merge relevant properties of PR and LQR controllers. This method simultaneously determines the MG control parameters and the current unbalanced factor generated at the distribution network. We select the traditional IEEE 13-bus test feeder network and place two MGs at strategic locations to validate our approach. Moreover, we use the Grey Wolf Optimizer (GWO) to find control parameters through a reliable fitness function that leads to high-performance microgrids. Finally, we conceive several tests to assess the efficacy of GWO for tuning the hybrid controller and compare the resulting data across distinct realistic operation conditions representing power quality events. So, we choose four case studies considering different renewable energy penetration indexes and power factors and evaluate the effects of the MGs over the distribution grid. We also compare the proposed hybrid PR+LQR controller against closely-related alternatives from the literature and validate its robustness and stability through the disk margin approach and the Nyquist criterion. Our numerical simulations prove that hybrid controllers driven by GWO are highly reliable strategies, yielding an average unbalanced current reduction of 30.03%.

Design and implementation of an improved adaptive embedded-factor current controller for three-phase grid-connected inverter

This paper presents an improved current controller based on a series proportional integral resonant structure in synchronous reference frame in order to address low-order harmonics issue of the injected-grid current for three-phase grid-connected inverter. Additionally, to improve dynamic performance, an adapted factor is embedded into the proposed controller structure. Moreover, to design the parameters of the proposed controller, different constraint conditions are investigated. Based on the proposed controller structure and parameters design method, satisfactory steady-state and faster dynamic performances are both obtained in comparison to those of the conventional parallel proportional integral resonant controller. What's more, the proposed controller is easy to implement in practice. Simulation and experimental results are finally given to verify the effectiveness and superiority of the proposed controller.

An asymmetric rotor model under external, parametric, and mixed excitations: Nonlinear bifurcation, active control, and rub-impact effect

This article explores the nonlinear dynamical analysis and control of a [Formula: see text] DOF system that emulates the lateral vibration of an asymmetric rotor model under external, multi-parametric, and mixed excitation. The linear integral resonant controller ([Formula: see text]) has been coupled to the rotor as an active damper through a magnetic actuator. The complete mathematical model, governing the nonlinear interaction among the rotor, controller, and actuator, is derived based on electromagnetic theory and the principle of solid mechanics. This results in a discontinuous [Formula: see text] DOF system coupled with two [Formula: see text] DOF systems, incorporating the rub-impact effect between the rotor and stator. The complicated mathematical model is investigated using analytical techniques, employing the perturbation method, and validated numerically through time response, basins of attraction, bifurcation diagrams, [Formula: see text] chaotic test, and Poincaré return map. The main findings indicate that the asymmetric system model may exhibit nonzero bistable forward whirling motion under external excitation. Additionally, it can whirl either forward or backward under multi-parametric excitation, besides the trivial stable solution. Furthermore, in the case of mixed excitation, the rotor displays nontrivial tristable solutions, with two corresponding to forward whirling orbits and the other one corresponding to backward whirling oscillation. These findings are validated through the establishment of different basins of attraction. Finally, the performance of the [Formula: see text] in mitigating rotor vibrations and averting nonlinear catastrophic bifurcations under various excitation conditions. Furthermore, the rotor’s dynamical behavior and stability are explored in the event of an abrupt failure of one of the connected controllers. The outcomes demonstrate that the proposed [Formula: see text] effectively eliminates dangerous nonlinearities, steering the system to respond akin to a linear system with controllable oscillation amplitudes. However, the sudden controller failure induces a local rub-impact effect, leading to a nonlocal quasiperiodic oscillation and restoring the dominance of the nonlinearities on the system’s response.

Variable Frequency Resonant Controller Based on Generalized Predictive Control for Biased-Sinusoidal Reference Tracking and Multi-Layer Perceptron

Variable Frequency Resonant Controller Based on Generalized Predictive Control for Biased-Sinusoidal Reference Tracking and Multi-Layer Perceptron

Research on current harmonic suppression of permanent magnet synchronous motor using smith predictive controller

Abstract Due to the dead time added to the operation of the motor inverter, the generated current harmonics are introduced into the synchronous motor, increasing the harmonic content of the motor. The higher harmonic content is the 5th, 7th, 11th, and 13th current harmonics, which can cause motor torque ripple [1]. To suppress the current harmonics that cause torque ripple, a control method of using a PI controller and a quasi-proportional resonant controller in parallel is considered to suppress current harmonics. However, the introduction of a proportional resonant controller can cause greater overshoots in the current response, and external environmental influences can also generate current disturbances. Therefore, a method based on Smith prediction-PID and quasi-proportional resonance controller cascade control structure is proposed to suppress current harmonics and current overshoot in response to this problem. Finally, the effectiveness of this method was verified through simulation experiments, thereby improving the stability of synchronous motor operation.

An improved IPT-PLL technology for single-phase grid-connected inverters in complex power grid conditions

Aiming at the common problems of frequency variations and harmonics in complex power grids, an improved inverse Park transform phase locked loop (IPT-PLL) technology for single-phase converters suitable for micro grid systems is proposed. Firstly, in the phase detection of PLL, the α component of Park transformation is selected as the reference voltage, and its orthogonal component is constructed using a 1/4 fundamental period delay method. Secondly, Lagrange interpolation polynomials are introduced to approximate fractional delay to solve the problem of delay calculation errors caused by frequency changes. Thirdly, in order to compensate for the poor ability of traditional proportional integral (PI) regulators, multi resonant controllers are superimposed to suppress low order harmonic disturbances. Finally, the design method and system performance of the PI regulator and each resonant controller are analyzed theoretically. The experimental results show that the proposed improved IPT-PLL method has strong adaptability to complex power grids. It can significantly improve the tracking performance of power grid frequency, suppress the interference of low order harmonics and DC bias. And it has good dynamic and static performance.

Low Voltage Ride Through Control Strategy for a Two-Stage Grid-Tied Solar Photovoltaic System with Grid Faults

This paper investigates a low voltage ride-through (LVRT) control strategy for a two-stage grid-tied solar photovoltaic (SPV) system with line-to-ground (L-G) and double line-to-ground (L-L-G) faults. A proportional resonant (PR) controller controls the SPV inverter based on classical and reactive power oscillation-based reference current generating techniques. The proposed method injects reactive power as an ancillary service to provide voltage support and prevent power outages, reduces the DC component injection into the grid currents, and finally injects sinusoidal currents into the grid, avoid voltage oscillations in the DC-link and limit the inverter current by operating the boost converter in non-MPPT mode during L-G & L-LG faults. Experimental results for reference current generation using classical method and proposed method are compared to highlight the proposed controller’s ability to maintain power quality during faults.

In situ electric-field control of ferromagnetic resonance in the low-loss organic-based ferrimagnet V[TCNE]x∼2

We demonstrate indirect electric-field control of ferromagnetic resonance (FMR) in devices that integrate the low-loss, molecule-based, room-temperature ferrimagnet vanadium tetracyanoethylene (V[TCNE]x∼2) mechanically coupled to PMN-PT piezoelectric transducers. Upon straining the V[TCNE]x films, the FMR frequency is tuned by more than 6 times the resonant linewidth with no change in Gilbert damping for samples with α = 6.5 × 10−5. We show this tuning effect is due to a strain-dependent magnetic anisotropy in the films and find the magnetoelastic coefficient |λs| ∼ (1–4.4) ppm, backed by theoretical predictions from density-functional theory calculations and magnetoelastic theory. Noting the rapidly expanding application space for strain-tuned FMR, we define a new metric for magnetostrictive materials, magnetostrictive agility, given by the ratio of the magnetoelastic coefficient to the FMR linewidth. This agility allows for a direct comparison between magnetostrictive materials in terms of their comparative efficacy for magnetoelectric applications requiring ultra-low loss magnetic resonance modulated by strain. With this metric, we show V[TCNE]x is competitive with other magnetostrictive materials, including YIG and Terfenol-D. This combination of ultra-narrow linewidth and magnetostriction, in a system that can be directly integrated into functional devices without requiring heterogeneous integration in a thin film geometry, promises unprecedented functionality for electric-field tuned microwave devices ranging from low-power, compact filters and circulators to emerging applications in quantum information science and technology.

Research on VIENNA rectifier QPR control and soft start

The principle and operation of the VIENNA rectifier is examined and the VIENNA mathematical model is developed. To address the issue that the three-phase VIENNA rectifier’s double PI controller finds it challenging to attain both rapidity and accuracy, a double closed-loop control approach consisting of inner loop quasi-proportional resonant control (QPR) and outer loop PI control is created. Aiming at the problems of inrush current on the grid side and DC bus voltage overshoot caused by the VIENNA rectifier in the startup process, the paper makes a theoretical analysis and designs a soft startup strategy. Then, the simulation model of the three-phase VIENNA rectifier control system was built in Simulink, which verified the correctness of the QPR control strategy and soft start scheme. Finally, an 8-kW prototype is set up, and the experimental results further confirm the effectiveness of the slope setting of the current.

Dual-layer loss reduction strategy for virtual distribution transformer integrating energy storage converter

To solve the problem that power quality disturbance aggravates the loss of distribution network in new power systems, this paper proposes a loss reduction strategy for virtual distribution transformer with integrated energy storage converter. Firstly, the concept of the virtual distribution transformer is defined through the analysis of the impact of complex power quality disturbances on distribution network losses. Secondly, a dual-layer control strategy for loss reduction based on the virtual distribution transformer is proposed. In the outer control layer, power quality control considering the load rate of the distribution transformer is achieved by extracting the integrated command signal that incorporates load fluctuations and using the improved quasi-proportional resonance controller. In the inner control layer, a grid-connected power stabilization strategy based on an adaptive double-window moving average filter is proposed, which adjusts the sliding window length in real-time according to the amplitude of fluctuation and state of charge, ensuring power meets the grid-connected standard while improving energy storage charge and discharge margins. Finally, simulation results validate that the proposed strategy enables the rapid realization of functions such as virtual capacity enhancement for distribution transformers, power flow control, and integration of new energy sources within short time scales while effectively reducing operating losses in low-voltage distribution networks.

Enhancing FRT capability of DFIG based on RC-crowbar considering the resonance and matching control strategies for different fault degrees

This paper compares the problems existing in the current fault ride-through (FRT) schemes of the doubly-fed induction generator (DFIG), and deeply analyzes the transient characteristics of DFIG during FRT. A comprehensive FRT scheme is proposed to improve the FRT capability by using an RC-crowbar and matching control strategy switching. The main innovation of this scheme lies in the consideration of resonance and other factors in the capacitance design of the RC-crowbar. To ensure that the DFIG still has good FRT capability after the RC-crowbar is cut off in advance in the later stage of FRT, an improved rotor side converter (RSC) control strategy is proposed for this situation. At the same time, to balance the reactive power on the stator side and accelerate the recovery of stator voltage throughout the entire FRT period, the control strategy of the grid side converter (GSC) is also improved. The comprehensive FRT scheme proposed in this paper can dynamically switch based on the degree of fault so that it still has good FRT ability when applied to different degrees of faults. Finally, the correctness and effectiveness of the proposed comprehensive FRT scheme were verified through simulation experiments.

Active control of Fano resonance in side-coupled resonator-cavity systems

The study delves into actively controlling Fano resonance within a single-mode microstrip cavity, coupled with a split ring resonator (SRR) incorporating a varactor diode. This resonance arises from the interference between the SRR and a Fabry–Pérot cavity, resulting in a sharply asymmetric transmission spectrum. The varactor diode, situated within the SRR gap, is biased electrically via an external DC voltage source. Through manipulation of this bias voltage, both the transmission frequency and amplitude of the pronounced Fano resonance can be dynamically adjusted. Notably, a significant frequency shift of 345 MHz is achieved, accompanied by a transmission modulation depth of up to 34.2 dB. Moreover, at the Fano peak frequency of 2.65 GHz, the composite SRR-cavity structure exhibits a notable change in group delay, shifting by 21.3 ns with the bias voltage varying from 5 V to 2.6 V. These findings hold promise for the development of electrically controlled functional photonic devices, facilitating their adaptability and versatility in practical applications.