Resonant Controller Research Articles

Resonance control to eliminate reactive power of an improved dual-port direct-drive wave energy converter

The single-port direct-drive wave energy converter (SPDDWEC) is widely utilized for harvesting ocean power among the existing wave energy converters (WECs) designs. Due to its working principle of generating reactive power inevitably and intermittent nature of the waves, the SPDDWEC is unable to provide continuous and stabilized energy to the grid. This paper proposed a dual-port resonance (DPR) control, which can achieve an improved dual-port direct-drive WEC (DPDDWEC) resonance by adjusting the dual electromagnetic force and electromagnetic spring force. The proposed DPR control can effectively avoid reactive power flow of the DPDDWEC, which can generate more energy than the SPDDWEC. Based on the established DPDDWEC kinematic state space model, the proposed DPR control is simulated and verified. The study results confirm the effectiveness of the proposed control method and correctness of theoretical analysis.

Control of stochastic and inverse stochastic resonances in a liquid-crystal electroconvection system using amplitude and phase noises

Stochastic and inverse stochastic resonances are counterintuitive phenomena, where noise plays a pivotal role in the dynamics of various biological and engineering systems. Even though these resonances have been identified in various systems, a transition between them has never been observed before. The present study demonstrates the presence of both resonances in a liquid crystal electroconvection system using combined amplitude and phase noises, which correspond to colored noises with appropriate cutoff frequencies (i.e., finite correlation times). We established the emergence of both resonances and their transition through systematic control of the electroconvection threshold voltage using these two noise sources. Our numerical simulations were experimentally confirmed and revealed how the output performance of the system could be controlled by combining the intensity and cutoff frequency of the two noises. Furthermore, we suggested the crucial contribution of a usually overlooked additional phase noise to the advancements in various noise-related fields.

An Adjustable deadtime Control Circuit for LLC Resonance Control Circuit

This study introduces the principle of deadtime generation and gives a deadtime control circuit. The deadtime can be adjusted by the current generated by the MOS transistor in the subthreshold region to control the charging and discharging speed of the capacitor dynamically, and the whole circuit is simulated in the cadence simulation environment. The simulation results show that the designed circuit can manually adjust the dead time in the range of 70 ns-1, 650 ns depending on external settings, and greatly reduce the complexity of the circuit.

Digital resonant control of power converters under variable grid frequency conditions

Introduction: The proportional resonant (PR) controller is known for its ability to effectively regulate sinusoidal current and voltage with low steady-state error. However, in the context of digital power systems, where operations are discrete in time, applying conventional PR controllers directly presents challenges. This study investigates the impact of various discretization methods on the performance of PR controllers, particularly under scenarios with varying reference frequencies.Methods: To assess the performance of digital PR controllers under varying reference frequency conditions, three discretization techniques are employed: zero-order hold (ZOH), impulse invariant (II), and zero pole matching (ZPM), in addition to the conventional deadbeat controller. These controllers are tested in conjunction with a single-phase pulse-width modulated (PWM) inverter, which is a crucial component in modern power systems.Results: Simulation results indicate the effectiveness of the different digital PR controllers in tracking both fixed and variable reference frequency signals while minimizing total harmonic distortion (THD) and steady-state error. When utilizing only the deadbeat controller, steady-state error and THD are measured at 4.9 V and 4.82%, respectively. However, the proposed ZPM-based digital PR controller significantly improves performance, reducing steady-state error to 0.12 V and THD to 0.45%, highlighting its superior performance.Discussion: The findings of this study emphasize the importance of choosing the appropriate discretization method when implementing PR controllers in digital power systems. The ZPM-based digital PR controller proves to be highly efficient in regulating power converters under varying grid frequency conditions. This research contributes to the understanding of digital PR controller behavior and its potential for improving power system performance, especially in scenarios with intermittent renewable energy resources and fluctuating grid frequencies.

Controller parameters design of a fractional‐order LCL‐type grid‐connected inverter

SummaryThe grid‐connected inverter (GCI) based on the fractional‐order LCL (FOLCL) filter can achieve good attenuation of resonant peak and simplify the control system design by omitting the capacitor current feedback as long as the orders of the inductor and capacitor are set appropriately. This paper investigates the parameter design methods of four types of controllers based on a single‐phase FOLCL‐type GCI without capacitor current feedback; the four controllers are the integer‐order proportional integral controller, fractional‐order proportional integral controller, integer‐order proportional resonance controller, and fractional‐order proportional resonance controller. Closed‐loop constraints based on steady‐state error, phase margin, and gain margin are given to design the specific parameters of each controller. The methods can accurately and quickly obtain the appropriate controller parameters to meet the system performance requirements without repeated trial and error. Simulations and hardware‐in‐the‐loop experiments verify the validity of the theoretical analyses.

Electric Field Control of Chiral Magnonic Resonators for Spin-Wave Manipulation

Electric Field Control of Chiral Magnonic Resonators for Spin-Wave Manipulation

A Novel Current Harmonic Suppression Method for HSPMSG Based on the Hybrid Rectifier

This paper presents a novel current harmonic suppression scheme for the high-speed permanent magnet synchronous generator (HSPMSG). Aiming to effectively reduce current harmonics for the HSPMSG, this paper focuses on two areas: improving the rectifier power topology and developing a current loop controller. Firstly, a hybrid rectifier based on Silicon-Carbide/Silicon (SiC/Si) is designed to equivalently increase the switching frequency of the HSPMSG to address the problem of low carrier frequency ratio. In addition, an improved space-vector-modulation (ISVM) strategy based on the hybrid rectifier is proposed. However, the harmonic distortion caused by rectifier nonlinearity will deteriorate as the switching frequency is increased. For further suppressing harmonic disturbances caused by rectifier nonlinearity, a resonant-super-twisting (R-STW) controller is designed by combining the resonant controller and the super-twisting (STW) controller in this paper. The stability of the STW is demonstrated by Lyapunov stability theory and the resonant controller is discretized. Finally, a number of simulations and experiments based on a high-speed permanent magnet synchronous generator are carried out to verify the effectiveness of the control method proposed in this paper.

Super-twisting resonant controller-based inverter nonlinearity compensation for permanent magnet synchronous motor drive system

In this paper, a novel super-twisting resonant controller with a fixed-time adaptive law (FTAL-STRC) is proposed to improve robustness and current smoothness of permanent magnet synchronous motor (PMSM). Firstly, the STRC controller is proposed, which incorporates the benefits of both the super-twisting controller (STC) and the quasi-resonant controller (QRC). Compared to the universal proportional integral resonant (PIR) control method, the proposed STRC can decrease the influence of inverter nonlinearity, and improve the robustness to parameters change, simultaneously. Secondly, an adaptive law based on fixed-time convergence theory (FTAL) is proposed to further compensate for the unknown disturbance, and realize fast tracking. Then, the composite control strategy is developed. Meanwhile, the stability of the proposed FTAL-STRC is proved rigorously. Finally, simulations and experiments are conducted to validate the effectiveness of the proposed method.

Analysis and Design of Voltage-controller Based on Single-state Feedback Active Damping for Grid-forming Converters

This paper investigates the analysis and design of digital single-loop voltage-controller for grid-forming voltage source converters with LC-filters. Inspired by the structure diagram of the passive damping method, the virtual resistance concept based on only capacitor voltage feedback is used to realize active damping without the need of any current sensor, reducing thus the system costs. It is revealed from the controller closed-loop analysis that the insertion of an integrator in series with a proportional and resonant controller can significantly improve stability margin and dynamic performance of the system, then only the proportional controller need to be determined for system stability and the resonant controller is merely used for zero steady-state tracking error, which facilitates the controller parameter tuning. A systematic design based on the root contours in the discrete z-domain is proposed to optimize the parameters of the controller. The largest distance between the poles of the closed-loop system and the unit circle is achieved, which indicates the fastest dynamic performance under desired stability margins. Meanwhile, a simple differentiator constructed by backward-Euler plus lead-compensator is used to replace the noise-sensitive derivative term. In order to evaluate the proposed control approach performance, the system is tested in laboratory setup under different load conditions. The obtained results verify the effectiveness of the proposed design method and validate the analysis.

Tracking control based on proportional resonant controller for electro‐hydraulic systems with input delay

AbstractThe growth of marine resources exploitation has led to increased research interest in electro‐hydraulic systems for marine simulation. This study proposes a proportional plus resonant (PR) controller to achieve high tracking performance for electro‐hydraulic systems. Due to the complex structure and non‐linear flow dynamics, establishing accurate mathematical models of electro‐hydraulic systems is challenging. The local linearization technique is applied to simplify the process of model establishment. The system gain is limited by the stability margin due to the input delay, resulting in a phase delay between the real trajectory and the desired reference. To compensate for the phase delay in tracking periodic reference with the traditional proportional and integral controller, a resonant item is added into the controller. The stability analysis of the closed‐loop system is performed using Routh‐Hurwitz criterion. Furthermore, the controller parameters are tuned based on the frequency characteristic to achieve high tracking performance and maintain the adequate stability margin. The effectiveness of the proposed PR controller in tracking periodic references is validated through numerical simulations and practical experiments.

Manipulations of Spin Wave by Photoelectrons in Ferromagnetic/Non-Ferromagnetic Alloyed Film.

Spin wave is considered an alternative carrier with great promise for information sensing. The feasible excitation and low-power manipulation of spin waves still remain a challenge. In this regard, natural light enables spin wave tunability is profoundly investigated in Co60 Al40 alloyed film. A reversible manner with 2° of the critical angle of the body spin wave is achieved successfully. Meanwhile, an eye-catching shift (817Oe) of the ferromagnetic resonance (FMR) field is obtained optically, leading to changes in magnetic anisotropy. Based on the modified Puszkarski's surface inhomogeneity model, the sunlight control of spin-wave resonance (SWR) can be comprehended by a photoelectron-doping-induced effective surface magnetic anisotropy change. Furthermore, the body spin wave is modulated stably with natural light illumination, confirming a non-volatile, reversible switching behavior. This work has both practical and theoretical importance for developing future sunlight-tunable magnonics/spintronics devices. This article is protected by copyright. All rights reserved.

Coordinated Control and Load Shifting-Based Demand Management of a Smart Microgrid Adopting Energy Internet

High renewable energy penetration worsens systems instability. Balancing consumption energy and generation output energy reduces this instability. This paper introduces coordination control to coordinate the flow of electricity between MG buses and to stabilize the system under variable load, generation conditions. The adopted MG regulates the bidirectional DC/AC main converter using digital proportional resonant controllers in a synchronous reference frame. A maximum power point tracker-based boost DC/DC converter enables the wind turbine and solar photovoltaic to harvest maximum power. Traditional methods such as perturb and observe and incremental conductance maximum power trackers cannot solve nonlinearity and inaccurate responses. This work provides a hybrid maximum power tracker strategy to modify the responses of standard maximum power point techniques based on particle swarm optimization-trained adaptive neuro-fuzzy inference system (ANFIS-PSO) to achieve quick and maximum solar power with minimal oscillation tracking. Concerning the management system, this paper adopts a recent meta-heuristic algorithms-based DSM program to modify consumers’ electricity use by shifting the load appliances to off-peak demand periods. The adopted algorithms for DSM are sparrow search algorithm (SSA), binary orientation search algorithm (BSOA), and cockroach algorithm (CA). Finally, based on energy Internet technology, ThingSpeak cloud-based MATLAB is adopted to gather and display real-time data streams and generate graphical analyses. The simulation results reveal that the recommended coordinating control produces quick grid frequency responsiveness and zero steady-state errors. The optimal demand management program minimizes peak energy consumption from 5.2 kWh to 4.6 kWh. All DSM methods cost 439.1 $ per month, compared to 484.4 $ for the nonscheduling load profile.

Non-Isolated Current-Fed Series Resonant Converter with Hybrid Control Algorithms for DC Microgrid

Module-level power electronics can optimize the power generation of photovoltaic panels, which requires a simple topology structure, high power conversion efficiency, and wide voltage gain, corresponding to irradiance variations. This paper proposes a non-isolated current-fed L-C series resonant converter and its control algorithms. The proposed converter can obtain a buck–boost voltage gain with the hybrid control algorithm utilizing the switching frequency modulation and asymmetric pulse width modulation. The proper power stage design can guarantee the soft-switching capability for the entire operating range. Also, the control strategy is designed to obtain a small rms current. The operational principle of proposed converter is analyzed in order to design the resonant tank and control strategy. The performance of designed converter can be verified with the experimental results with a 500 W prototype converter.

Closed-Form Harmonic Compensation Using Resonant Controllers Applied to Four-Leg VSI

Harmonic compensation employing resonant controllers applied to voltage source inverters generally requires complex techniques or a trial-and-error process to design the controller parameters. This paper proposes a closed-form solution for designing digital Proportional-Resonant controllers applied to three-phase four-leg inverters. The proposal presents a sequential procedure that uses closed-form expressions to establish the harmonic frequencies at which resonant stages must be added to comply with individual voltage harmonic distortion standards. The method eliminates the need for a trial-and-error process and ensures compliance with THD and individual harmonic distortion limits. The frequencies that require compensation and the gains of the resonant controllers are determined by evaluating the difference that presents the output harmonic impedance of the inverter concerning normalized three-phase harmonic impedance limits defined in this work. Furthermore, this paper adopts the harmonic distortion restrictions imposed by the Standard IEC 61000-2-2, allowing the harmonic impedance limits to be defined for the reference non-linear load indicated in IEC 62040-3. Experimental results are presented to validate the proposed design using a 5 kVA four-leg inverter, feeding balanced, unbalanced, linear, and non-linear loads.

Decoupled Mitigation Control of Series Resonance and Harmonic Load Current for HAPFs With a Modified Two-Step Virtual Impedance Shaping

Hybrid active power filter (HAPF) with large series capacitor can reduce the rating of power converter, but it is associated with the risk of low frequency <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">LC</i> resonance. The overlapping of series <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">LC</i> resonance frequencies and the dominated load harmonic current frequencies makes the conventional active damping approaches less effective. To overcome this challenge, a two-step harmonic virtual impedance control approach is developed to compensate the load harmonic current and reshape the closed-loop equivalent circuit of the HAPF for resonance damping. First, the shunt capacitor harmonic voltage is regulated according to a term that is associated with both the harmonic load current and the HAPF harmonic line current. Further investigation on the equivalent circuit transformations indicates that HAPF is equivalent to a controlled current source to compensate for load harmonic current and a virtual harmonic damping resistor between the series capacitor and grid impedance. Accordingly, the resonance damping and the nonlinear load low order harmonic current compensation can be well decoupled with minimal interference.

Voltage Regulating Strategy of a New LCC/S+L Inductive Power Transfer System

In the voltage control of the inductive power transfer (IPT) system, a cascaded DC-DC converter is normally adopted which reduces the power density. However, the wireless communication between the transmitter and the receiver may lead to a delay of control as well as communication instability. This paper proposes a new LCC/S+L resonance topology for the IPT system, which can realize single-stage voltage regulation on the receiving side with both buck and boost capability. Based on the fundamental wave analysis method, this paper analyzes the working principle of LCC/S+L resonant topology. Then the control strategy of the phase shift angle between bridges and within bridges is obtained by the voltage of both ends of the series inductor and the load voltage vector. It is verified by simulation that the proposed new resonance topology and control strategy can achieve output voltage regulation of 300-500 V with a constant 375 V input DC voltage.

A proposed optimized equivalent circuit and performance analysis of dielectric barrier discharge ozone generator

&lt;span lang="EN-US"&gt;Traditionally, low-frequency power supplies are used in dielectric barrier discharge (DBD) ozone generators. These generators require a very high output voltage. This may limit ozone production due to limitations imposed by the dielectric strength of the insulating material. Low-frequency generators also present low efficiency, large volumes, and difficulty in controlling ozone production. On the other hand, the advantages of high frequency DBD ozone generators are the increased power density applied to the chamber electrodes, and the voltage applied to the ozone chamber decreases, allowing for higher ozone production efficiency. From this point of view, in order to enhance and control the DBD ozone generator operating at high frequency, it is necessary to determine all parameter values and optimize the equivalent model for this type of generator. This work presents and proposes the practical methodologies used to extract all parameters of the high voltage high frequency (HVHF) transformer which can be used in these systems. Resonant frequency control techniques are presented in this paper. Elimination of the stray capacitance effect will also be implemented in this paper.&lt;/span&gt;

Bidirectional motion characteristics of resonant inertial impact rotating piezoelectric motor based on self-clamping structure

A new working principle for multimodal excitation of a resonant bidirectional rotary inertial impact piezoelectric motor with a self-clamping structure was developed based on previous research on piezoelectric motors. Unlike previous piezoelectric motors that relied on single harmonic waves for unidirectional rotation, in this motor, we can simply change the driving signal characteristics of the motor without changing the structure of the piezoelectric motor to excite multiple vibration modes, thereby achieving rotation in both directions. Compared with other bidirectional resonant motors, the structure and control signal are simpler. The finite element simulation software COMSOL5.5 was used to simulate the working mode of the motor, and the results were in good agreement with the final experiment. During the experiments, the optimal operating frequency of the motor prototype was 900 Hz. The maximum output speed of the motor prototype was 3.9 rad/s, the maximum output torque was 15 N mm, and the maximum resolution was 0.248° under the conditions of 240 Vp-p voltage, 900 Hz frequency, and 7.8 N mm preload torque.

Single-Switch Non-Isolated Resonant DC-DC Converter for Single-Input Dual-Output Applications

This paper describes a new configuration of Cuk and SEPIC (Single-Ended Primary Converter) ZVS-QR (zero-voltage switching quasi-resonant) combination DC-DC converter for bipolar output with a single switch. The proposed topology employs a single ground-referenced power switch, which simplifies the gate drive design with a single L-C resonant network and provides a bipolar output voltage with good regulation, acceptable efficiency and a step-down/up conversion ratio. This configuration provides dual-output voltage by switching the power switch to zero voltage, which is an interesting alternative for many applications where small size, light weight and high power density are very important aspects. In order to verify its performance, a SEPIC–Cuk Combination ZVS-QR prototype with a cost-effective commercial resonant controller was designed and tested. The experimental results show that the proposed combined topology is suitable for Single-Input Dual-Output (SIDO) applications.

Decoupled Speed and Flux Control of a Three-Phase Permanent Magnet Synchronous Motor under an Open-Circuit Fault Using a PR Current Controller

Presented in this article is a method for decoupling the speed and flux control of a three-phase permanent magnet synchronous motor (PMSM) during an open-circuit fault (OCF) using a current controller based on proportional resonant (PR) control techniques. The suggested control approach is relatively simple to implement and maintains good motor operation during the open circuit. PMSM performance under pre-fault, OCF, and post-fault conditions were investigated using Matlab/Simulink and an experimental setup based on a dSPACE DS1104. The conducted investigations provide strong evidence supporting the efficacy and resilience of the suggested control approach during OCF conditions.