Resonant Controller Research Articles

Flexible neutral point displacement overvoltage suppression method based on backstepping control in unbalanced distribution networks

Three-phase AC distribution networks are required to operate as symmetrically as possible for optimal performance, but the three-phase-to-ground parameters are asymmetric in the field due to network construction deviation, resulting in the three-phase voltage unbalance and the neutral point displacement overvoltage. The neutral point displacement overvoltage would endanger the distribution networks and even damage critical power equipment. Therefore, the flexible asymmetry suppression device (FASD) with the topology of a cascaded H-bridge (CHB) inverter and the backstepping control (BSC) method is proposed for limiting the neutral point displacement overvoltage in this paper. The FASD outputs the current to the grid for compensating the unbalanced distribution networks caused by the asymmetry of three-phase-to-ground parameters and realizing the suppression of the neutral point displacement overvoltage. A current-based BSC method is designed to improve the stability and reliability of the CHB inverter, and the effectiveness of neutral point displacement overvoltage suppression based on the BSC method is verified by experimental results, and the advantage of the proposed method is shown by comparing with proportional-integral control (PIC) method, sliding mode control (SMC), and proportional resonant control (PRC) methods.

Noise-induced enhancement of stability and resonance in a tri-stable system with time-delayed feedback

In this paper, the mean first-passage times and the stochastic resonance in an asymmetric tri-stable system are studied by considering time-delayed feedback, which is driven by a periodic signal and correlated noises. Both the theoretical expressions for small time delay and the numerical results for large time delay are provided to explore the noise-induced enhancement in stability and resonance. The obtained results suggest that the correlation between the additive and multiplicative noises plays a constructive role on system dynamical behaviors, such as the appearing of noise enhanced stability and stochastic resonance, which can be optimized by choosing proper time-delayed feedback gain for fixed time delay. When the feedback gain is fixed, the time delay can greatly accelerate the crossing between left well and middle well, while cannot effectively enhance the crossing velocity between right well and middle well. Moreover, for small time delay, theoretical analysis predicts that stochastic resonance effect and control performance can be substantially improved by choosing appropriate combination of time delay and feedback gain. For large time delay, the phenomenon of stochastic resonance is enhanced by selecting small feedback gain and large asymmetry.

Numerical Robustness Evaluation of Floating-Point Closed-Loop Control Based on Interval Analysis

Power-electronics-based systems have penetrated into several critical sectors, such as the industry, power generation, energy transmission and distribution, and transportation. In this context, the system’s control, often implemented in real-time processing units, has to meet stringent requirements in terms of safety and repeatability. Given the growing complexity of the implemented algorithms, floating-point arithmetic is being increasingly adopted for high-performance systems. This paper proposes to assess the numerical stability of the control algorithms by means of an interval analysis. The case study of an electric drive is considered, given the wide adoption of such systems and the importance they hold for the safety of the applications. In particular, two different control strategies—the resonant control and the vector space decomposition—are examined, and a sensitivity analysis based on the proposed technique highlights the different characteristics of the two with respect to numerical stability. The proposed method shows how the resonant control is more robust to variations of the controller gain coefficients with respect to the numerical stability, which could make it the preferred choice for mission-critical electric drive control.

Driving Circuit Design for Piezo Ceramics Considering Transformer Leakage Inductance

This paper presents the circuit and control method for piezo-ceramic drives. With the proposed method, a gap is imposed in the transformer core to increase the leakage inductance. This flattens the voltage gain curve of the piezo-ceramic driver over the resonant frequency range, so voltage gain changes are insensitive to frequency changes. In addition, resonant frequency tracking and power control methods are developed, while the circuit is capable of zero-voltage soft-switching such that the circuit operation efficiency can be improved. In order to solidify the practicality of the circuit design, mathematical analysis and experimental validations have been thoroughly performed. The test results help to confirm the effectiveness of the proposed method and demonstrate its practicality in industrial applications.

The Suppression of Modular Multi-Level Converter Circulation Based on the PIR Virtual Impedance Strategy

In recent years, with the rise of the electric vehicle industry, there has been significant research on charging and power supply vehicle technologies for electric vehicles. In terms of the corresponding converter usage, modular multi-level converters (MMCs) are also increasingly used in the field of electric vehicle power supply research because of their unique advantages. However, the circulating current problem of MMCs has not been effectively addressed in existing domestic and international studies. In this paper, we propose a proportional-integral resonant (PIR) control method combined with virtual impedance for the optimal suppression of the MMC internal circulating current problem based on the comparison and generalization of the existing methods. Based on the analysis of the working principle of MMCs, this paper proposes and adopts the control strategy of combining virtual impedance and proportional-integral resonance to suppress the circulating current and builds a simulation model in MATLAB to verify that the control strategy proposed in this paper is feasible.

An Improved Hydraulic Energy Storage Wave Power-Generation System Based on QPR Control

According to the inherent characteristics of the hydraulic power take-off (PTO) system, the output power of a generator tends to be intermittent when the wave is random. Therefore, this paper aims to improve the effective utilization of wave energy and reduce power intermittency by constructing a topology with two branches to transmit electrical energy. Firstly, the wave-to-wire (W2W) model of the system is constructed. Secondly, the W2W model is simulated by using synovial and quasi-proportional resonance (QPR) control with regular and irregular incident waves, and the results of PI control are compared. Then, the control strategy in simulation is verified by experiments. The simulation and experimental results show that the control strategy has better performance, and the stability of the system output power is greatly improved.

Bifurcation behaviour of resonant magnetic perturbation control of edge localized modes in tokamaks: nonlinear simulation results.

In this article, some novel results of two fluid nonlinear simulations on the control of edge localized modes (ELMs) in tokamaks by resonant magnetic perturbations (RMPs) are presented. Many experiments around the world have demonstrated that RMPs are effective in possibly mitigating or even completely suppressing strong (type I) ELMs that would seriously degrade confinement and could cause other heat-flux problems in both present (e.g. JET) and planned future tokamaks (ITER). Our simulations demonstrate that non-axisymmetric RMPs with toroidal mode numbers [Formula: see text] and suitable field-strengths (kAturns) at the plasma wall imply significant bifurcations in their ability to mitigate or even suppress type-I ELMs, qualitatively similar to RMP effects on ELMs reported in experiments. This article is part of a discussion meeting issue 'H-mode transition and pedestal studies in fusion plasmas'.

Primary resonance and feedback control of the fractional Duffing-van der Pol oscillator with quintic nonlinear-restoring force

<abstract><p>In the present paper, the primary resonance and feedback control of the fractional Duffing-van der Pol oscillator with quintic nonlinear-restoring force is studied. The approximately analytical solution and the amplitude-frequency equation are obtained using the multiple scale method. Based on the Lyapunov theory, the stability conditions for the steady-state solution are obtained. The bifurcations of primary resonance for system parameters are analyzed, and the influence of parameters on fractional-order model is also studied. Numerical simulation shows that when the parameter values are fixed, the curve bends to the right or left, resulting in jumping phenomena and multi-valued amplitudes. As the excitation frequency changes, the typical hardening or softening characteristics of the oscillator are observed. In addition, the comparisons of approximate analytical solution and numerical solution are fulfilled, and the results certify the correctness and satisfactory precision of the approximately analytical solution.</p></abstract>

Modeling and Current Control Strategy for Novel Two-Phase DC-Biased Vernier Reluctance Machine

This paper proposes a drive topology and vector control strategy for a two-phase DC-biased vernier reluctance machine (DCB-VRM) with non-overlapping windings. Since the DC path needs to be reserved in the DCB-VRM drive topology, more power switching devices are needed in theory. In order to generate DC bias sinusoidal current and reduce costs, a low-cost drive topology is applied. The machine's mathematical model in the stationary and synchronous rotating frame is derived. Then the vector control strategy is proposed. Through effective control of the <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">dqdc</i> -axis currents, maximum torque per ampere (MTPA) can be achieved. The resonant controllers are paralleled with the proportional-integral (PI) controller to suppress current harmonics in the control method. Finally, the simulation and experimental results validate that the proposed drive topology and control strategy can effectively control the two-phase DCB-VRM.

Closed loop proportional resonant controller controlled DC microgrid system with advanced material technology in solar PV system

Direct Current microgrid has emerged as one of the major research fields in recent years due to the higher level of benefits of the DC system when compared to the AC system, such as energy storage, flexibility with modernized loads, and renewable energy sources. Many studies have been conducted on the DC microgrid system in order to improve its efficiency. In this work, by using conventional PI controllers and advanced controllers like fractional order proportional integral derivative (FOPID) and proportional resonance (PR) controllers, a DC microgrid system is controlled. A closed-loop DC micro-grid containing sustainable power sources, stockpiled components, and transients is introduced. The PI controller is the most commonly used in power frameworks for assisting with the control of microgrids. Aside from PI, there are a slew of independent and hybrid regulators that can serve significantly better than PI in terms of microgrid framework relevance. The closed-loop DC microgrid framework systems with FOPID-FOPID and PR-PR-based DC microgrid structures are investigated and re-enacted utilising Simulink in MATLAB, and their outcomes are introduced. This paper also looks at advanced solar cell material technology, which has been used as an energy source in the DC microgrid system for higher power delivery. In this work, the performance of several solar cell types is compared along with an overview of recent developments in solar cell technology.

Self-reliant solar PV based microgrid with seamless transition capabilities at weak grid conditions

• The extended proportional complex filter (EPCF) control allows a fast estimation of the quadrature and in-phase fundamental load current components with reduced harmonics within the prescribed limit. • The EPCF-based control has extracted the fundamental component of load current with high rate of convergence and better system response. The variations on load, utility, and solar array radiation are well established in simulation and test results. The PQ is enhanced at unbalancing of load, change in solar insolation and grid adverse conditions of voltages unbalances. The performance of the system is found satisfactory and its response is enhanced at adverse grid conditions. Experimental results have demonstrated that the THD are as recommended by the IEEE-519 standard even during weak grid conditions. • A comparative analysis is included, which validates the superior filtering capability and improved power quality during weak grid conditions. In addition a tabular comparative analysis is included to support its effectiveness while addressing abnormalities of the grid. • The EPCF-PLL grid synchronization and phase angle estimator scheme has provides fast mode transition, frequency tracking and uninterrupted supply to the load during non availability of the grid. This has given precise phase angle estimation. Conventional PLL controllers are non-adaptive towards large frequency. EPCF-PLL has provided effective frequency adaptability. This makes the synchronization process immune from frequency variation and voltage unbalance. • The proportional resonant controller with harmonic compensation (PRHC) controller provides satisfactory performance under all the intermittent conditions overcoming the tradeoff between improved steady-state and transient performance. This paper presents a solar photovoltaic (PV) based energy conversion system with seamless transfer to the grid. To provide satisfactory performance in grid connected mode, a control based on extended proportional complex filter (EPCF) is used. The EPCF is used to estimate the fundamental current component (LCFC) of local loads At the linkage point (LP), the power quality (maintaining IEEE-519 standard) is improved using this control. The EPCF maintains balanced grid currents whether PV array generation is available or not. It provides effective mitigation of harmonics and monitors the flow of active power, which improves the grid current quality.This control provides versatile actions such as extraction of LCFC, harmonics elimination, DC offset removal, robust performance during voltages unbalance etc. The same control technique (EPCF) along with phase locked loop is used for smooth synchronization; it reduces the use of another algorithm, which improves the dynamic response of the system. This control estimates exact phase and frequency variation for the seamless mode switching. It provides frequency adaptation during mode shifting. The comparative results validate that the control based on EPCF has a faster detection of grid in comparison with existing controls. During the grid-outage, the proportional resonant (PR) controller with harmonics compensation (HC) based control algorithm enhances performance of the microgrid. This provides successful solution for harmonics compensation and minimizing steady state errors. Simulated and experimental results, in various scenarios, have verified the effectiveness of the controllers and demonstrate the favourable solution in controlling the unfavorable grid conditions.

Compact Substrate Integrated Waveguide Wideband Bandpass Filter With Post-Manufacturing Tuning Capabilities

In this paper, a miniaturized wideband bandpass filter in coaxial substrate integrated waveguide (SIW) technology is presented. To improve the response selectivity and coupling control, a multi-layer structure has been implemented, introducing both strong magnetic and electric couplings. To reduce the physical size of the device, surfaced-mounted device (SMD) capacitors have been integrated on the top layer. These allow both resonant frequency and capacitive coupling level control. Thus, a 4-th order Chebyshev filter with an absolute bandwidth (BW) of 2.9 GHz centered at 5.35 GHz has been designed, fabricated and measured. An extremely small filter size of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$7 \times 7$ </tex-math></inline-formula> ,mm2 has been obtained. A study of manufacturing tolerances are also presented in this paper, together with a post-manufacturing response correction allowed by the SMD elements. As it is shown in the paper, the filter’s out-of-band rejection can be easily enhanced by introducing additional transmission zeros (TZs).

A Review of DC-DC Resonant Converter Topologies and Control Techniques for Electric Vehicle Applications

A Review of DC-DC Resonant Converter Topologies and Control Techniques for Electric Vehicle Applications

Резонансный ПИ-регулятор для судовой электрогидравлической стабилизированной платформы

The problem of stabilizing the angular position of the platform installed on the deck of a water vessel is considered. The platform is used to accommodate navigational equipment and radar antennas of communication systems that require stabilization of the platform's angular position in space under conditions of wave perturbations of the aquatic environment to work efficiently. The task under discussion is to eliminate the influence of wave perturbations on the platform's angle of inclination relative to the horizon. A mathematical model of a stabilized platform with an electric hydraulic drive is considered and a technique for synthesizing a control system that provides effective suppression of the influence of wave perturbations on the angular position of the platform is developed. The novelty of the proposed approach to the synthesis of the control system of the stabilized platform position consists in applying the time-scale separation method for calculating the resonant proportional-integral controller of the electrohydraulic drive of the platform. The results of numerical simulation of the control system under discussion are presented.

Proportional–Resonant Controller Based on Virtual Impedance for Harmonic Suppression of ESS-UPS System

Proportional–Resonant Controller Based on Virtual Impedance for Harmonic Suppression of ESS-UPS System

Integral resonant control preserving the rigid body mode of torsional vibration systems*

Integral resonant control (IRC) is an effective vibration control technique for flexible structures including multiple vibration modes, even though the controller is a simple first-order system. However, IRC can not be directly applied to flexible structures with rigid body modes. This paper proposes a new method to apply IRC by choosing an angle difference output in which the rigid body modes are unobservable but only elastic modes observable. The proposed method is effective for applying IRC to torsional vibration systems where the control objective is to reduce only torsional vibration modes while leaving the rigid body mode preserved. However, side effects such as an inverse response and a brake effect occur depending on the choice of the controller parameter. This paper clarifies the condition for the inverse response and the magnitude of the brake effect on the rigid body motion analytically. A new design method for the IRC controller is then presented based on the trade-off between the brake effect and the vibration suppression performance.

On the rub-impact force, bifurcations analysis, and vibrations control of a nonlinear rotor system controlled by magnetic actuator integrated with PIRC-control algorithm

This article presents the Proportional Integral Resonant Controller (PIRC-controller) as a novel control strategy to suppress the lateral vibrations and eliminate nonlinear bifurcation characteristics of a vertically supported rotor system. The proposed control algorithm is incorporated into the rotor system via an eight-pole electromagnetic actuator. The control strategy is designed such that the control law (PIRC-controller) is employed to generate eight different control currents depending on the air-gap size between the rotor and the electromagnetic poles. Then, the generated electrical currents are utilized to energize the magnetic actuator to apply controllable electromagnetic attractive forces to suppress the undesired lateral vibrations of the considered rotor system. According to the suggested control strategy, the whole system can be represented as a mathematical model using classical mechanics' principle and electromagnetic theory, in which, the rub-impact force between the rotor and the stator is included in the derived model. Then, the obtained discrete dynamical model is analyzed using perturbation techniques and validated numerically through bifurcation diagrams, frequency spectrums, Poincare maps, time responses, and steady-state whirling orbit. The obtained results illustrate that the proposed control algorithm can mitigate the nonlinear vibration and eliminate the catastrophic bifurcations of the rotor system when the control gains are designed optimally. In addition, the system dynamics are analyzed when the rub-impact occurrence between the rotor and the pole housing is unavoidable. The acquired results revealed that the system may perform periodic-1, periodic-n, or quasiperiodic motion with one of two oscillation modes depending on both the impact stiffness coefficient and the dynamic friction coefficient.Article HighlightsNonlinearity dominates the uncontrolled rotor response, where it suffers from the jump phenomenon and multiple solutions.The proposed controller forces the Jeffcott rotor to respond as a linear system with small oscillation amplitudes.The rotor oscillates with full-annular-rub or partial-rub-impact mode when rub-impact occurs between the rotor and stator.

Ultrabroadband and Multifunctional Achromatic Mikaelian Lens on an Elastic Plate

The emergence and development of acoustic artificial materials stimulate a large number of applications for the manipulation of ultrasonic and elastic waves. Most of the reported metasurfaces and metamaterials only work effectively at a given frequency and target a fixed functionality. Reconfigurable designs may solve this problem, to a certain extent, but require the introduction of complex active control components. Here, by integrating multiple functionalities on a conformally mapped Mikaelian lens with a hyperbolic secant refractive-index distribution, a broadband passive lens is presented and accomplished on an elastic plate. Just by adjusting the location and type of source, different regulations of flexural waves can be switched from one sort to another. Through projecting the refractive-index profile onto the thickness of the plates, the proposed Mikaelian lens is designed and fabricated. Theoretical prediction and experimental results demonstrate beam scanning at an angle of up to 120\ifmmode^\circ\else\textdegree\fi{} from 30 to 180 kHz and achromatic subwavelength focusing with a full width at half maximum of around 0.3\ensuremath{\lambda} from 30 to 120 kHz. Without using locally resonant materials or active control elements, this work provides a feasible way to construct multifunctional flexural-wave devices.

Proportional Integral Resonant and Proportional Derivative Controllers Applied to Zero Sequence Harmonic Compensation in Four-Wire Microgeneration Systems

Proportional Integral Resonant and Proportional Derivative Controllers Applied to Zero Sequence Harmonic Compensation in Four-Wire Microgeneration Systems

High frequency oscillation damping for the VSC-HVDC connects to a wind farm via a cable transmission line

When a wind farm connects to the grid via a high voltage direct current transmission based on voltage source converter (VSC-HVDC), high frequency oscillation (HFO) is a critical issue that threatens the system stability, this issue has been reported in many HDVC projects all over the world. The current research proved the negative resistance brought by the effect of control delay in VSC-HVDC is a primary cause of instability. This paper ulteriorly analyzes the influence on system stability caused by the long ac cable between the wind farm and the VSC-HVDC, and indicates that the effect of the cable transmission line can contribute to the system instability as well, while the existing damping methods did not consider this effect. Then the control failure of the exiting damming methods when considering the cable transmission line is analyzed and verified by the impedance analysis theory. Thereby, this paper proposed a vector modified resonant controller (VMRC) which can independently and flexibly regulate the magnitude and phase of HVDC impedance, to solve the HFO issue caused by the combined effect of the control delay and the cable transmission line. Also, the design procedure of the proposed control strategy is detailly presented. Finally, experimental results are provided to verify the correctness of the mechanism analysis and the validity of the proposed control strategy.