Resonant Controller Research Articles

Closed-Loop Control of Photonic Ring Resonators by Means of Photo-Thermal Plasmonic Sensors

Closed-Loop Control of Photonic Ring Resonators by Means of Photo-Thermal Plasmonic Sensors

Current Controller Design of Grid-Connected Inverter with Incomplete Observation Considering L-/LC-Type Grid Impedance

This paper presents a current control design for stabilizing an inductive-capacitive-inductive (LCL)-filtered grid-connected inverter (GCI) system under uncertain grid impedance and distorted grid environment. To deal with the negative impact of grid impedance, LC-type grid impedance is considered in both the system model derivation and controller design process of an LCL-filtered GCI system. In addition, the integral and resonant control terms are also augmented into the system model in the synchronous reference frame to guarantee the reference tracking of zero steady-state error and good harmonic disturbance compensation of the grid-injected currents from GCI. By considering the effect of grid impedance on the control design process, an incomplete state feedback controller will be designed based on the linear-quadratic regulator (LQR) without damaging the asymptotic stabilization and robustness of the GCI system under uncertain grid impedance. By means of the closed-loop pole map evaluation, the asymptotic stability, robustness, and resonance-damping capability of the proposed current control scheme are confirmed even when all the system states are not available. In order to reduce the number of required sensors for the realization of the controller, a discrete-time current-type full-state observer is employed in this paper to estimate the system state variables with high precision. The feasibility and effectiveness of the proposed control scheme are demonstrated by the PSIM simulations and experiments by using a three-phase GCI prototype system under adverse grid conditions. The comprehensive evaluation results show that the designed control scheme maintains the stability and robustness of the LCL-filtered GCI when connecting to unexpected grids, such as harmonic distortion and L-type and LC-type grid impedances. As a result, the proposed control scheme successfully stabilizes the entire GCI system with high-quality grid-injected currents even when the GCI faces severe grid distortions and an extra grid dynamic caused by the L-type or LC-type grid impedance. Furthermore, low-order distortion harmonics come from the background grid voltages and are maintained as acceptable limits according to the IEEE Std. 1547-2003. Comparative test result with the conventional one also confirms the effectiveness of the proposed control scheme under LC-type grid impedance thanks to the consideration of LC grid impedance in the design process.

Application of optimized photovoltaic grid-connected control system based on modular multilevel converters

Photovoltaic power generation is a promising method for generating electricity with a wide range of applications and development potential. It primarily utilizes solar energy and offers sustainable development, green environmental benefits, and abundant solar energy resources. However, there are many external factors that can affect the output characteristics of Photovoltaic cells and the effectiveness of the grid-connected control system. This study describes the introduction of Modular Multilevel Converter (MMC) technology into photovoltaic power generation systems to improve power generation efficiency. It proposes optimizing and improving the technology by adjusting the temperature and magnitude of lighting and combining traditional algorithms to propose a composite control algorithm. The photovoltaic power generation system employs the modular multi-level converter technology to enhance power generation efficiency alongside optimization and improvement. The temperature and size of light are regulated alongside the traditional algorithm to introduce the composite control algorithm. The improved composite algorithm surpasses the traditional one after experimental comparison of the results. The testing of a model photovoltaic power grid-connected system shows that the combination of modular multi-level converter technology and a photovoltaic grid-connected system, incorporating composite proportional integral control and quasi-proportional resonant control algorithms, yields improved results and feasibility. With rationality and effective control. The simulation results show that at 0.5 s, the light intensity suddenly increases from 750 to 1000 W/m2, and the direct-current voltage suddenly increases for a short time, but then decreases rapidly and finally returns to a stable level close to the rated voltage. From this, it can be seen that when the light intensity continues to change, the voltage value on the direct-current bus side of this MMC grid-tied photovoltaic system can still be maintained close to the rated value, ensuring the operational stability of the entire system. Sensibly and effectively controlled. The implementation of MMC technology in photovoltaic power generation systems enhances power generation efficiency, whilst simultaneously supporting the advancement of photovoltaic power generation and contributing towards environmental protection in the long term.

Improved Position Sensorless Resonant Frequency Tracking Control Method for Linear Oscillatory Machine

To improve the reliability of control system and obtain the maximum output efficiency, it is very necessary to carry out the position sensorless piston stroke control and the resonance frequency tracking control for linear oscillatory machine (LOM) at the same time. The conventional resonant frequency tracking control method based on model reference adaptive system (MRAS) has the problem of low estimation accuracy caused by inaccurate model parameters. In order to obtain more accurate resonant frequency, an improved position sensorless resonant frequency tracking control method is proposed in this article. In this method, the adjustable model is constructed based on the mechanical dynamics equation of LOM to track the system resonant frequency. A hybrid terminal sliding-mode observer (HTSMO) is designed to replace the conventional reference model, which can obtain more accurate velocity reference signal for adjustable model by introducing the current error feedback link, thereby further improving the resonant frequency tracking accuracy. Moreover, a second-order generalized integrator (SOGI) is introduced to filter the estimated velocity signal of HTSMO. The filtered velocity signal is not only used for the adjustable model to track the resonant frequency, but also used to obtain the smooth piston stroke signal for the stroke closed-loop control. Comprehensive simulation and experimental results have proved the effectiveness and the superiority of the proposed method.

Selective PQD Power Control Strategy for Single-Phase Grid-Following Inverters

This paper proposes the selective PQD power control strategy based on proportional-integral controllers devised in stationary <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">abc</i> -reference frame for single-phase <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">grid-following</i> inverters. Its physical behavior and mathematical model are presented in detail and the system output impedance is derived. It is shown that the proposed control accurately tracks active, reactive, and selective distortion power terms. Experimental results show that the proposed control strategy effectively rejects source disturbances, achieving low values of current distortion even under heavily distorted grid voltages. Stability analysis under stiff and weak grids and DC-link voltage control for photovoltaic applications are evaluated. It is also shown that the implemented technique requires 26% less execution time in the main interruption than conventional solutions using proportional-integral plus resonant controllers.

Dynamical Analysis, Circuit Design, and Fuzzy Prescribed Performance Backstepping Control of the FO Weakly Coupled MEMS Resonators

Dynamical Analysis, Circuit Design, and Fuzzy Prescribed Performance Backstepping Control of the FO Weakly Coupled MEMS Resonators

Single-phase photovoltaic off-grid inverter based on quasi-PR control

Given the rapid growth of renewable energy generation, photovoltaic inverters have gained widespread adoption in power generation systems. To achieve improved precision in control and enhanced quality in the output waveform of the inverters, this article presents a single-phase photovoltaic inverter designed for both grid-connected and off-grid systems. It utilizes a quasi-proportional-resonant control technique. Initially, the mathematical representation of the grid-connected and off-grid inverter is established. Following this, the quasi-proportional resonant control strategy is introduced, with the corresponding implementation method of the controller derived from its equivalent block diagram. Furthermore, the control block diagrams of the grid-connected and off-grid inverters undergo a detailed analysis, and the system’s transfer function is obtained from the control block diagram. The incorporation of grid voltage feedforward control is introduced for examining the system’s tracking performance. Ultimately, the proposed control approach is validated for its effectiveness and practicality through Simulink simulation.

MaRGE: A graphical environment for MaRCoS

The open-source console MaRCoS, which stands for “Magnetic Resonance Control System”, combines hardware, firmware and software elements for integral control of Magnetic Resonance Imaging (MRI) scanners. Previous developments have focused on making the system robust and reliable, rather than on users, who have been somewhat overlooked. This work describes a Graphical User Interface (GUI) designed for intuitive control of MaRCoS, as well as compatibility with clinical environments. The GUI is based on an arrangement of tabs and a renewed Application Program Interface (API). Compared to the previous versions, the MaRGE package (“MaRCoS Graphical Environment”) includes new functionalities such as the possibility to export images to standard DICOM formats, create and manage clinical protocols, or display and process image reconstructions, among other features conceived to simplify the operation of MRI scanners. All prototypes in our facilities are commanded by MaRCoS and operated with the new GUI. Here we report on its performance on an experimental 0.2 T scanner designed for hard-tissue, as well as a 72 mT portable scanner presently installed in the radiology department of a large hospital. The possibility to customize, adapt and streamline processes has substantially improved our workflows and overall experience.

Control of vortex shedding and acoustic resonance of a circular cylinder in cross-flow

This study experimentally investigates the effectiveness of a control rod in suppressing self-excited acoustic resonance within a range of Reynolds numbers (Re) spanning from 2.1 × 104 to 1.6 × 105. The investigation focuses on specific parameters, including diameter ratio (d/D) values of 0.1, 0.2, and 0.3; gap ratio (G/D) values of 0.05, 0.1, and 0.2; and angular positions (θ) ranging from 0 to 180 degrees. Comparative analyses are conducted between cases featuring the control rod and a reference case (base case) without it. The near-wake flow field is characterized using Particle Image Velocimetry (PIV), and aeroacoustic response measurements are employed to quantify the aeroacoustic noise emission, particularly during self-excited acoustic resonance. Simultaneous measurements of fluctuating lift force and aeroacoustic response measurements, facilitate the quantification of energy transfer from the flow field to the acoustic field during self-excited acoustic resonance. The results reveal that the control rod’s placement significantly impacts the Strouhal periodicity, with outcomes heavily dependent on the rod’s angular orientation. At certain angular positions, the control rod reduces the sound pressure level (SPL) generated during acoustic resonance excitation. However, at different angular positions, the rod exacerbates resonance excitation. This variability is attributed to the control rod’s profound influence on the vortex core formation and the energy transfer mechanism during acoustic resonance.

Investigation of a 25 kV–50 Hz Railway-Substation Power Supply Based on a Back-to-Back Modular Multilevel Converter Topology

This paper presents a preliminary study of a 25 kV–50 Hz railway substation power supply system. The control of a back-to-back converter based on modular multilevel converter (MMC) technology was investigated to fit with the power quality requirements of the application. One of the main challenges is the presence of constraining load conditions, under which the train circulation variability, low-frequency harmonics and critical power transients can notably decrease the power quality and lead to instability. In order to address this, cascaded controllers based on resonant controllers are proposed to ensure the desired performance. Furthermore, balancing voltage algorithms are added to avoid stress phenomena and additional losses in the studied power conversion interface. The paper presents the design of the control stages and demonstrates the robust performance of the system using a realistic loading condition of a railway substation.

Circulating current mitigation for renewable-based modular seven-level converter using deep learning-optimized fractional-order proportional resonant controller

Circulating current mitigation for renewable-based modular seven-level converter using deep learning-optimized fractional-order proportional resonant controller

Harmonic suppression of active disturbance rejection control for virtual synchronous generators

SummaryVirtual synchronous generators (VSGs) are comprised of an outer power loop and inner cascaded control loops. The dynamic performance of the output interface is severely degraded when microgrid loads exhibit variability and nonlinearity. Therefore, robustness against load disturbances must be possessed by any voltage control scheme. In this paper, a proportional resonance‐linear active disturbance rejection control (PR‐LADRC) scheme based on an improved linear extended state observer (ILESO) is proposed for VSG voltage control. In comparison with the traditional linear extended state observer (LESO), the differential state variable of the output voltage is utilized to increase the observation bandwidth; consequently, the proposed ILESO can effectively overcome the disadvantage of phase lag when tracking disturbances. Additionally, a proportional resonance controller is incorporated into the LESO feedforward channel to suppress voltage harmonics. The proposed scheme enhances the disturbance observation bandwidth compared to traditional strategies, resulting in a substantial improvement in both the disturbance observation capability of LADRC and the harmonic suppression ability of the VSG system. Theoretical analysis and simulations are conducted to validate the effectiveness of the proposed PR‐LADRC approach.

Adaptive Active Disturbance Rejection Control for Uncertain Current Ripples Suppression of PMSM Drives

Under complex working conditions, there are uncertain periodic and aperiodic disturbances in the curr- ent loop of permanent magnet synchronous motor (PMSM) drives. These uncertain disturbances can lead to uncertain current ripples, deteriorating the current loop performance. To deal with the problem, this paper proposes an adaptive active disturbance rejection control (ADRC) for the current loop to suppress the uncertain current ripples. In the ada- ptive ADRC, the extended state observer is optimized by the adaptive resonant controller so that it can estimate both the uncertain periodic and aperiodic disturbances. Thus, the adaptive ADRC can suppress both the uncertain periodic and aperiodic disturbances to attenuate the uncer- tain current ripples in the current loop, and it does not need the disturbance information. In addition, the stability of the observer in the adaptive ADRC is systematically analyzed by the singular perturbation theory and the averaging theorem. Finally, the effectiveness of the adaptive ADRC is validated on a 2.2-kW PMSM platform.

Half‐bridge secondary series resonant converter control for full voltage range

SummaryThis paper proposes a full‐range regulation method for half‐bridge secondary series resonant converter. With the proposed method, the resonant converter can achieve full‐range regulation within a narrow frequency range regardless of the load level. Besides, the converter can be used for the battery charger systems and programmable power supply systems. The primary‐side transistors and the secondary‐side diodes are zero‐voltage switching turned on and zero‐current switching turned off, respectively. In‐depth analysis reveals the characteristics, that is, operation principle, voltage conversion ratio, component stresses, and ZVS condition of the half‐bridge secondary series resonant converter with the proposed method. Besides, the performance comparisons among the different methods are conducted to present the merits of the proposed method. Further, the performance comparisons between the half‐bridge secondary series resonant converter and primary series resonant converter with the proposed method are executed to show their superiority with different turns ratio range of the transformer, respectively. When the turns ratio is larger than 0.5 and smaller than 1, the performance of the half‐bridge primary series resonant converter is better; when the turns ratio is equal to 1, the two configurations feature the same performance; while when the turns ratio is larger than 1, the half‐bridge secondary series resonant converter is preferable. The experimental results validate the theoretical analysis.

Resonant Gate Drive Circuit with Active Clamping to Increase Efficiency and Reliability

In power converters with high switching frequency, drive losses constitute a significant portion of the overall power losses. Resonant gate drivers can reduce drive losses, thereby enhancing the efficiency. However, resonant drivers suffer certain challenges: parameter drifts lead to the mismatch between the resonant frequency and the control frequency, and this mismatch can cause gate-to-source voltage overshoot. Moreover, the resonant driver is susceptible to external interference. This paper proposes a resonant circuit structure and control timing scheme aimed at overcoming these limitations. By incorporating a half-bridge clamp circuit, the proposed design achieves voltage clamping, thereby insulating the system from disturbances caused by mains power fluctuations. When there is a mismatch in resonant frequencies, the strategy employs a combination of hardware circuit diodes and control system timing to prevent overvoltage issues. Additionally, the utilization of MOSFETs minimizes the loss caused by prolonged current flow through body diodes, further reducing the resonant driving losses. Simulations have demonstrated the system’s stability under varying resonant parameters and its effective anti-interference capabilities in voltage clamping. Experiments achieved a power saving of 83.3% at a 1 MHz operating frequency. Both simulations and experimental validations confirm the feasibility of the proposed solution, its effectiveness in interference suppression, handling of resonant mismatches, and its role in further augmenting power conservation.

A Grid-Connected Inverter with Grid-Voltage-Weighted Feedforward Control Based on the Quasi-Proportional Resonance Controller for Suppressing Grid Voltage Disturbances

A grid-connected inverter (GCI) with LCL filters is widely used in photovoltaic grid-connected systems. While introducing active damping methods can improve the quality of grid-connected current (GCC), the influence of grid voltage disturbances can still significantly impact the quality of GCC, leading to stability degradation, especially in weak grid conditions. This paper proposes a grid-voltage-weighted feedforward control scheme based on the quasi-proportional resonance (QPR) controller. This scheme introduces compensatory terms with different proportional coefficients in the voltage feedforward, controlled by the QPR controller. Through a series of analyses, reasonable inverter parameters are first designed. Then, the proposed system model is built in Matlab Simulink. Through simulation experiments and comparisons with various types of operating conditions, the effectiveness of the proposed system scheme is validated. It minimizes the impact of grid voltage disturbances, suppresses the influence of grid harmonics on the control system, improves current quality, and enhances the stability of the GCI system.

Electrostatic Gating of Spin Dynamics of a Quasi-2D Kagome Magnet.

Electrostatic gating has emerged as a powerful technique for tailoring the magnetic properties of two-dimensional (2D) magnets, offering exciting prospects including enhancement of magnetic anisotropy, boosting Curie temperature, and strengthening exchange coupling effects. Here, we focus on electrical control of the ferromagnetic resonance of the quasi-2D Kagome magnet Cu(1,3-bdc). By harnessing an electrostatic field through ionic liquid gating, significant shifts are observed in the ferromagnetic resonance field in both out-of-plane and in-plane measurements. Moreover, the effective magnetization and gyromagnetic ratios display voltage-dependent variations. A closer examination reveals that the voltage-induced changes can modulate magnetocrystalline anisotropy by several hundred gauss, while the impact on orbital magnetization remains relatively subtle. Density functional theory (DFT) calculations reveal varying d-orbital hybridizations at different voltages. This research unveils intricate physics within the Kagome lattice magnet and further underscores the potential of electrostatic manipulation in steering magnetism with promising implications for the development of spintronic devices.

Quantifying the performance enhancement facilitated by fractional-order implementation of classical control strategies for nanopositioning

For most nanopositioning systems, maximizing positioning bandwidth to accurately track periodic and aperiodic reference signals is the primary performance goal. Closed-loop control schemes are employed to overcome the inherent performance limitations such as mechanical resonance, hysteresis and creep. Most reported control schemes are integer-order and combine both damping and tracking actions. In this work, fractional-order controllers from the positive position feedback family namely: the Fractional-Order Integral Resonant Control (FOIRC), the Fractional-Order Positive Position Feedback (FOPPF) controller, the Fractional-Order Positive Velocity and Position Feedback (FOPVPF) controller and the Fractional-Order Positive, Acceleration, Velocity and Position Feedback (FOPAVPF) controller are designed and analysed. Compared with their classical integer-order implementation, the fractional-order damping and tracking controllers furnish additional design (tuning) parameters, facilitating superior closed-loop bandwidth and tracking accuracy. Detailed simulated experiments are performed on recorded frequency-response data to validate the efficacy, stability and robustness of the proposed control schemes. The results show that the fractional-order versions deliver the best overall performance.

Robust resonant plus proportional tracking controller for diving motion control of an autonomous underwater vehicle

Robust resonant plus proportional tracking controller for diving motion control of an autonomous underwater vehicle

Modal Phase-Matched Bound States in the Continuum for Enhancing Third Harmonic Generation of Deep Ultraviolet Emission.

Coherent deep ultraviolet (DUV) light sources are crucial for various applications such as nanolithography, biomedical imaging, and spectroscopy. DUV light sources can be generated by using conventional nonlinear optical crystals (NLOs). However, NLOs are limited by their bulky size, inadequate transparency at the DUV regime, and stringent phase-matching requirements for harmonic generation. Recently, dielectric metasurfaces support high Q-factor resonances and offer a promising approach for efficient harmonic generation at short wavelengths. In this study, we demonstrated a crystalline silicon (c-Si) metasurface simultaneously exciting modal phase-matched bound states in the continuum (BIC) resonance at the fundamental wavelength of 840 nm with a higher degree of freedom for precise control of the BIC resonance and a plasmonic resonance at the wavelength of 280 nm in the DUV to enhance third harmonic generation (THG). We experimentally achieved a Q-factor of ∼180 owing to the relatively large refractive index of the c-Si and the geometric symmetry breaking of the structure. We realized THG at a wavelength of 280 nm with a power of 14.5 nW by using a peak power density of 15 GW/cm2 excitation. The measured THG power is 14 times higher than the state-of-the-art THG dielectric metasurfaces using the same peak power density in the DUV regime, and the maximum obtained THG power enhancement factor is up to 48. This approach relies on the significant third-order nonlinear susceptibility of c-Si, the interband plasmonic nature of the c-Si in the DUV, and the strong field confinement of BIC resonance to boost overall nonlinear conversion efficiency to 5.2 × 10-6% in the DUV regime. Our work shows the potential of c-Si BIC metasurfaces for developing efficient and ultracompact DUV light sources using high-efficacy nonlinear optical devices.