High Dynamic Response Research Articles

A current prediction correction control algorithm for permanent magnet synchronous linear motor

When a permanent magnet synchronous linear motor (PMSLM) is used in a direct drive system, the current loop of drive control system is required to have a high response speed in order to achieve a high dynamic response of the system. With the traditional PI control strategy, the bandwidth of the system’s current loop is limited. In this paper, a predictive correction control algorithm is used in the current loop of permanent magnet synchronous linear motor drive control system. The algorithm is to predict the instruction voltage vector required by the next switching cycle so that the target current of the control system can reach the instruction reference current value within the next switching cycle. It is used to improve the response speed of the system current loop and realize the precise control of the single PWM cycle of the system current loop.

Research on a High-Precision State-of-Charge Estimation Method Based on Forgetting Factor Recursive Least Squares and Adaptive Extended Kalman Filter Applied to LiFePO4 Battery

The state-of-charge (SOC) estimation accuracy is closely associated with the estimation method and the battery parameter identification performance. The battery parameter identification method based on forgetting factor recursive least squares (FFRLS) has the advantages of high parameter identification accuracy and fast dynamic response speed. On this basis, the performance of two SOC estimation methods, the extended Kalman filter (EKF) and adaptive extended Kalman filter (AEKF) are compared and studied. The results show that AEKF has better steady-state and dynamic SOC estimation performance, but the estimation accuracy and dynamic response performance are still not objective. To further improve the performance of SOC estimation, a joint SOC estimation method based on FFRLS-AEKF is proposed, and the SOC estimation experimental results with FFRLS-AEKF and AEKF are conducted. The experimental results show that the proposed joint SOC estimation method based on FFRLS-AEKF has a better steady-state and dynamic performance of SOC estimation. The maximum absolute error of the proposed algorithm is 4.97%. As the battery working time increases, the SOC estimation accuracy continues to converge to the true value, and the average absolute error is reduced to 2.5%. The proposed method and theoretical analysis are proven to be correct and feasible.

Parameters Variation to Estimate Performance Characteristics of 3-Phase Asynchronous Motor

The 3-phase asynchronous squirrel cage motors (SCIM) are main competitor machines placed instead of other motors in the commercial and industrial fields. The stator and rotor material selection and construction topology influence the electrical machine design. The results illustrated with the motor of a 15KW, variable controlled speed, for the constant frequency of 50 Hz or 60 Hz. The motor parameters created inside the simulation model must be matched with the value of a standard parameter for SCIM to achieve a high dynamic response. This work examines the effect of the parameters variation for synchronous motor on the performance characteristics at starting point and at a load change for different time and speed regions. Changing of the rotor power is taken into consideration, this occurs with dynamic change of the hydraulic pump load from the valve.In the industrial applications, production,and manufacturing, till present there are still struggles to find the most holistic environment of the SCIM to achieve its efficiency at the lowest cost and same time control the motor performance, so we predicted the method of reducing the most effective motor parameters to improve the efficiency.The offline method used the SCIM parameters to calculate the time-varying current, torque, and rotor speed. The results illustrated that this method was fully consistent with the experiment tests and the standard theoretical values.A MATLAB program is used to simulate this study. The simulation model proved the feasibility of the proposed method with encouraging performance.

A high-fidelity constitutive model considering hydrostatic damage for predictions of high dynamic properties of concrete structures

This paper establishes a new high-fidelity constitutive model for predicting the high dynamic responses of concrete structures. The presented model incorporates the damage caused by hydrostatic pressure into the constitutive equations of concrete, while the hydrostatic damage induced strength and stiffness degradation behaviors have not been considered in existing models. In this model, two hydrostatic damage equations are introduced respectively to quantify the strength and stiffness degradation caused by hydrostatic damage. Based on this, a shrinking failure surface method is proposed for the failure criterion to capture the strength degradation, and a novel unloading/reloading law is developed for the equation of state to describe the stiffness reduction non-linearly. The model is implemented in the hydrocode LS-DYNA through the user-defined material subroutine. Numerical hydrostatic tests using a single element are conducted to verify the accuracy of the model firstly, and the corresponding predictions are in good agreement with the experimental results. Numerical simulations of penetration tests are then performed, where the damage mechanisms including hydrostatic damage and shear damage are identified. The comparisons between simulation and test results indicate that the presented model reflects the dynamic responses of concrete structures more accurately and reproduces the damage evolution of concrete more completely.

Sliding mode control of four‐leg inverters in a stand‐alone microgrid for unbalance, neutral to ground voltage, and harmonics compensation

AbstractIn a stand‐alone microgrid, voltage control is an important issue to keep the grid balanced under unbalanced load conditions. The other important challenges in microgrids include handling the neutral to the ground voltage (NGV) as well as total harmonic distortion (THD) under its limits due to the IEEE standards. A four‐leg inverter is the best choice for a three‐phase transformerless inverter employed in a stand‐alone microgrid. To control the inverter, sliding mode control (SMC) is a well‐known nonlinear control system to handle unbalanced and nonlinear load conditions as it can provide high sinusoidal load voltage with high performance and fast dynamic response. This paper proposes an enhanced SMC control method for minimizing the NGV and THD in addition to compensating for unbalanced load voltage conditions simultaneously in a three‐phase four‐leg inverter. In order to verify the results of the proposed method, simulation results with MATLAB/Simulink are presented to confirm the effectiveness of the proposed SMC under various load conditions. The proposed method provided fast dynamic response and fixed switching frequency. Further, a significant reduction occurred in NGV and THD. The simulation results of this method compared with the MPC method indicated the better performance of the proposed method against the unbalanced and nonlinear various load conditions.

Virtual Flux Direct Power Control for Vienna Rectifier Under Unbalanced Grid

The Vienna rectifier is being broadly utilized in many industrial applications, which makes it essential to address its challenges. This article conducts the virtual flux-based direct power control and proposes an improved switching table for the Vienna rectifier under a balanced or unbalanced grid's voltage. Accordingly, the proposed method improves the THD of the three-phase input current when the grid voltage is unbalanced. Moreover, employing the virtual flux concept eliminates using three-phase input voltage. This results in reducing the cost of the converter. One of the challenges in the Vienna rectifier is to consider the current direction in the control design. Accordingly, the proposed switching table is designed based on the input current's sector. Furthermore, the positive and negative sequences of the input currents and virtual flux are utilized to correctly estimate the instantaneous input active and reactive power under the unbalanced grid voltage condition. Moreover, the proposed method can balance the output capacitors in balanced and unbalanced grid voltage conditions. This method possesses a high dynamic response due to hysteresis bands. Finally, a 430-watt laboratory prototype of the Vienna rectifier is implemented, and the accuracy of the proposed VFDPC is verified through the experimental results.

African vulture optimizer algorithm based vector control induction motor drive system

<span lang="EN-US">This study describes a new optimization approach for three-phase induction motor speed drive to minimize the integral square error for speed controller and improve the dynamic speed performance. The new proposed algorithm, African vulture optimizer algorithm (AVOA) optimizes internal controller parameters of a fuzzy like proportional differential (PD) speed controller. The AVOA is notable for its ease of implementation, minimal number of design parameters, high convergence speed, and low computing burden. This study compares fuzzy-like PD speed controllers optimized with AVOA to adaptive fuzzy logic speed regulators, fuzzy-like PD optimized with genetic algorithm (GA), and proportional integral (PI) speed regulators optimized with AVOA to provide speed control for an induction motor drive system. The drive system is simulated using MATLAB/Simulink and laboratory prototype is implemented using DSP-DS1104 board. The results demonstrate that the suggested fuzzy-like PD speed controller optimized with AVOA, with a speed steady state error performance of 0.5% compared to the adaptive fuzzy logic speed regulator’s 0.7%, is the optimum alternative for speed controller. The results clarify the effectiveness of the controllers based on fuzzy like PD speed controller optimized with AVOA for each performance index as it provides lower overshoot, lowers rising time, and high dynamic response.</span>

Fast autofocus method for piezoelectric microscopy system for high interaction scenes.

Piezoelectric objective driver positioners are increasingly used in the field of microscopy. They have the advantages of high dynamic and fast response. This paper presents a fast autofocus algorithm for highly interactive microscope system. First, the Tenengrad gradient of the down-sampled image is used to calculate the image sharpness, and Brent search method is adopted to quickly converge to the correct focal length. At the same time, the input shaping method is used to eliminate the displacement vibration of the piezoelectric objective lens driver and further accelerate the image acquisition speed. Experimental results show that the proposed scheme can improve the speed of the automatic focusing task of the piezoelectric objective driver and improve the real-time focus of the automatic microscopic system. HIGHLIGHTS: A high real-time autofocus strategy. A vibration control method suitable for a piezoelectric objective driver.

Design accuracy and magnetic field analysis of a dual-armature bearingless flux reversal motor

A dual-armature bearingless flux reversal motor (DBFRM) is proposed. The permanent magnet in the motor is located on the stator side, the armature winding is located on the stator side and the rotor side, the suspension winding is located at the stator side, the rotor teeth are embedded in the slotted non-magnetic material rotor barrel, and the stator and rotor cores are made of laminated silicon steel. The DBFRM demonstrates the characteristics of high speed, long life, and fast dynamic response and has unique advantages in power energy saving and energy storage. Compared with the traditional bearingless flux reversal motor, the DBFRM shows better fault tolerance. Based on the theory of air-gap magnetic field modulation, the torque and the levitation mechanism of the motor are expounded from four perspectives—permanent magnetic field, armature reaction magnetic field, electromagnetic torque, and levitation force—which lays the foundation for the establishment of an accurate mathematical model of levitation force and torque.

Controller Design and StabilityAnalysis of Intensification Process using Analytical Exact Gain-Phase Margin approach.

The controllable intensified process has received immense attention from researchers in order to deliver the benefit of process intensification to be operated in a desired way to provide a more sustainable process toward reduction of environmental impact and improvement of intrinsic safety and process efficiency. Despite numerous studies on gain and phase margin approach on conventional process systems, it is yet to be tested on intensified systems as evidenced by the lack of available literature, to improve the controller performance and robustness. Thus, this paper proposed the exact gain and phase margin (EGPM) through analytical method to develop suitable controller design for intensified system using Proportional-Integral-Derivative (PID) controller formulation, and it was compared to conventional Direct Synthesis methods (DS), Internal Model Control (IMC), and Industrial IMC method in terms of the performance and stability analysis. Simulation results showed that EGPM method provides good setpoint tracking and disturbance rejection as compared to DS, IMC, and Industrial IMC while retaining overall performance stability as time delay increases. The Bode Stability Criterion was used to determine the stability of the open-loop transfer function of each method and the result demonstrated decrease in stability as time delay increases for controllers designed using DS, IMC, and Industrial IMC, and hence control performance degrades. However, the proposed EGPM controller maintains the overall robustness and control performance throughout the increase of time delay and outperform other controller design methods at higher time delay with [Formula: see text] uncertainty test. Additionally, the proposed EGPM controller design method provides overall superior control performance with lower overshoot and shorter rise time compared to other controllers when process time constant is smaller in magnitude ([Formula: see text]) than the instrumentation element, which is one of the major concerns during the design of intensified controllers, resulting overall system with a higher order. The desired selection of gain margin and phase margin were suggested at 2.5 to 4 and 60 °-70[Formula: see text],respectively, for a wide range of control conditions for intensified processes where higher instrumentation dynamic would be possible to achieve robust control as well. The proposed EGPM method controller is thought to be a more reliable design strategy for maintaining the overall robustness and performance of higher order and complex systems that are highly affected by time delay and high dynamic response of intensified processes.

Hybrid low switching frequency modulation strategy with high dynamic response for high‐power voltage source converter

AbstractFor high‐power converters, the low switching frequency (SF) modulation represented by selective harmonic elimination pulse width modulation (SHE‐PWM) is crucial to reduce the switching loss and enhance the efficiency with a good steady‐state performance. However, since the advantages of SHE‐PWM mainly come from the fixed switching angle distribution limited by non‐linear equations, switching angles should be adjusted slowly. This requires that the bandwidth of proportional integral (PI) controllers be limited hugely, resulting in a poor dynamic response. As the most popular control to improve the dynamic response, finite‐control‐set model predictive control (FCS‐MPC) has a worse steady‐state performance under low SF because of large errors caused by a long prediction period and harmonics caused by space vector PWM (SVPWM). Therefore, a hybrid modulation strategy with an acceptable complexity is proposed in this article, which combines SHE‐PWM and FCS‐MPC. PI + SHE‐PWM is adopted in a steady state with low SF, while MPC + SVPWM is used in a transient state with high SF. By studying smooth switching from the modulation level and control level, the proposed method can eliminate the current surge when switching between PI + SHE‐PWM and MPC + SVPWM. Experiments verify that the proposed method have a good steady‐state performance and high dynamic response simultaneously under overall low SF.

Impact of Sequential Model Predictive Control on Induction Motor Performance: Comparison of Converter Topologies

Finite Set Model Predictive Control (FS-MPC) is a widely used technique in power electronic converter applications. One challenge in FS-MPC implementation is selecting appropriate weighting factors, as there is currently no established methodology for finding the best values. An alternative approach is to consider cost functions without weighting factors, as used by the Sequential Model Predictive Control (SMPC). In this paper, the performance of SMPC applied to induction motors is analyzed. The SMPC strategy involves sequentially evaluating simple cost functions by considering a limited number of available switching states for the power electronic converter. This number is the control parameter of the SMPC. The parameter’s domains and a selection criteria based on THD were established in this investigation. The power converter topologies studied include the Voltage Source Inverter (VSI) and the Neutral Point Clamped three-level (3L-NPC). Simulations performed in PLECS software and Hardware-in-the-Loop (HIL) tests using an RT Box for valid parameters satisfy the characteristics of the classical predictive control, such as good control variables tracking and high dynamic response. For a VSI converter, increasing the control parameter results in reduced harmonic distortion, while for an NPC converter, optimal results are achieved with control parameter values within a specific range.

Review of Flux-Weakening Algorithms to Extend the Speed Range in Electric Vehicle Applications With Permanent Magnet Synchronous Machines

This article reviews Flux-Weakening (FW) algorithms for Permanent Magnet Synchronous Machines (PMSMs), focusing on the automotive sector, especially in electric and hybrid electric vehicles. In the past few years, the spread of Electric Vehicles (EVs) has improved the technology of electric machines and their control to achieve more compact and competitive solutions. PMSMs are the most widespread electric machines used in EVs thanks to their high-power density and potential operation at constant power range during high speed. Such high speed implies a high electromotive force. An FW technique is mandatory to reduce the electromagnetic flux generated by the electric machine due to the voltage limits of the traction inverter and the energy source. This article classifies and analyses the state-of-the-art FW control strategies by comparing their main advantages and drawbacks. The Vector Current Control (VCC) method that regulates the modulus of the applied voltage is the most common one in the literature thanks to i) its robustness to parameter modification and model unsureness, ii) low computational complexity, and iii) high dynamic response and control stability.

A Low Detent Force DS-PMSLM Based on the Modulation of Cogging and End Forces

This article presents a low detent force double-sided permanent-magnet synchronous linear motor (DS-PMSLM), which contains two flat-type stators and a mover. The mover is constituted of a fiberglass support plate and Halbach array permanent magnets attached on both surfaces of this plate, which provides a large thrust force and low mover mass for high dynamic response. For the sake of reducing the thrust ripple, a modulation method of the cogging and end forces is proposed based on the destructive interference. The even-order harmonics in cogging and end forces are reduced by adjusting the width of the side slots and the lengths of end teeth, respectively. In order to reduce the odd-order harmonics of the detent force, the cogging force and end force are modulated to reverse phases and identical amplitudes by changing the equivalent lengths of four end teeth. An integrated subdomain analytical model considering the cogging and end effects is built to optimize five structural parameters of the stators for low detent force. Finally, the prototype and testing platforms are set up and the experimental results validate that the proposed DS-PMSLM can achieve a low thrust ripple of less than 1.5 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$ \%$</tex-math></inline-formula> .

Design and Optimization of Interdigital Capacitive Humidity Sensor with Highly Sensitive and Dynamic Response Time

Humidity sensors are widely used in various fields of life. In meteorological detection, the sensor must have high sensitivity and fast dynamic response time due to extreme environmental interference. However, the sensitive mechanism of the humidity sensor determines that the dynamic response time will inevitably be increased while improving the sensitivity, which undoubtedly creates difficulties for sensor design. This article takes the interdigitated capacitive humidity sensor as the research object and proposes an optimal design scheme for the sensor that considers high dynamic response time and sensitivity. By constructing the sensor’s theoretical mathematical model, the influence of each structure is analyzed. The theoretical model has been verified by finite element simulation to have an accuracy higher than 95%. The article constructs the sensor optimization objective equation based on this model. Through analysis, within the range of structural parameters set in the article, to improve the sensitivity and reduce the dynamic response time of the sensor, the width and spacing of the interdigital electrodes should have a minimum value of 3 μm and a maximum value of 14 μm, respectively. The thickness of the electrode layer and the moisture-sensitive layer should be flexibly adjusted according to the application to ensure the lowest value of the optimization objective function. To further improve the sensor’s performance, the article optimizes the electrode structure and heating strategy of the sensor heating layer, which not only enhances the uniformity of heat transfer but also increases the optimal heat transfer area by 6% compared with the traditional scheme.

Self-Balancing Control of Yarn Number Based on a Novel Sensorless PMSM Speed Drive System

The performance of the motor drive system is responsible for the yarn feeding quality of the weft accumulator. The existing motor drive systems have problems such as slow start–stop and poor dynamic response performance, resulting in slow yarn tracking speed and low precision of the weft accumulator. This article proposes a new self-balancing yarn number control method based on a novel sensorless permanent magnet synchronous motor (PMSM) speed drive system. The novel sensorless PMSM speed drive system is constructed to improve the dynamic response performance of PMSM by integrating an improved sliding mode observer, a simplified initial position detection method, and a new hybrid control method. The self-balancing yarn number closed-loop control method is proposed based on a pseudoderivative feedback controller to improve the response speed and accuracy of yarn feeding. The general design principle is given, and various tests are carried out. The results show that the proposed drive system has characteristics of a fast start–stop and high dynamic response, which can meet the high-response and high-precision yarn feeding requirements of the weft accumulator.

An Improved One-Cycle Control Algorithm for a Five-Phase Six-Leg Switching Power Amplifier in Active Magnetic Bearings

To achieve levitation in active magnetic bearing (AMB) systems, levitation coils must be driven by a switch power amplifier (SPA). Therefore, SPA performance is important to stable levitation. In previous studies, five-phase six-leg (5P6L) SPA topology was proposed to reduce hardware costs. However, current tracking performance degrades due to the coupling problem of the five-phase current and freewheeling loss. Then, the rotor may deviate markedly from the balance position, affecting rotor stability. The keys to solving these problems lie in the duty cycle control of the common leg and the compensation of freewheeling loss. This article proposes an improved one-cycle control (OCC) algorithm in which the duty cycle of the common leg is optimized by finite control set model predictive control (FCS-MPC), and the freewheeling loss is compensated for by a high-precision mathematical model. In addition, the parameter uncertainty of the FCS-MPC model is analyzed, and the convergence of the optimization algorithm is investigated. Simulations and experiments show that the proposed algorithm is effective, and the high dynamic response and low steady-state error performance of SPA are achieved.

Modeling Analysis of Superbuck Converter in Dual-Loop Competition Control

A Battery Charge Regulator system based on the Superbuck converter is presented, the working principle of the Superbuck converter is analyzed and the small signal model is established. In order to meet the requirements of wide input range and high dynamic response of the Superbuck converter, a double closed-loop control system is designed with output voltage and output current dual loop control as outer loop and input current control as inner loop. The stability of the control loop is verified by the Bode plot, and the simulation result of the system in two working conditions are given to support the theoretical analysis.

Control for induction motor drives using predictive model stator currents and speeds control

&lt;span&gt;This paper is presented for designing a new controller using the predictive model current and speed control method for the asynchronous motor. This control method is based on traditional predictive controller development to have a cascade structure similar to the rotor flux control (field-oriented control) and direct torque control (DTC). Therefore, this control method will have two control loops. Both inner and outer loop controllers use predictive power. The outer ring is speed control, while the internal circle is stator current control. The inner loop is based on the finite control set – model predictive control (FCS-MPC), while the outer ring to take full advantage of the high dynamic response of the inner circle uses the deadbeat MPC. MATLAB simulation results show that this control method has performance equivalent to traditional controllers while minimizing overshoot and having fast, on-demand response times.&lt;/span&gt;

Predictive-adaptive sliding mode control method for reluctance actuator maglev system

The control performance of the reluctance actuator maglev system is seriously affected by inherent nonlinearities (e.g. hysteresis, eddy current, flux leakage, etc.) and external disturbances. To this end, this paper proposes an enhanced unknown system dynamics estimator (USDE)-based sliding mode control (USDE-SMC) method by a novel predictive-adaptive switching (PAS) controller (USDE-SMC-PAS). First, a USDE is incorporated into SMC to compensate for the uncertainties, including the external disturbance, the parametric uncertainty, and the model mismatch of inherent nonlinearities; second, an adaptive switching (AS) controller is used to reduce chattering; finally, the switching controller is modified by PAS to enhance the dynamic response ability and uncertainty rejection ability with reduced chattering. In the PAS controller, the switching gain comprises a filtered estimation error part and a residual error part, which are obtained by a first-order filter and an adaptive law, respectively. Consequently, the strong nonlinearity and uncertainty compensation ability, high levitation accuracy, high dynamic response, and reduced chattering property can be achieved simultaneously. The stability properties of USDE-SMC, USDE-SMC with an AS controller (USDE-SMC-AS), and USDE-SMC-PAS in the closed-loop system are investigated by the Lyapunov theorem. Simulations and experiments are provided to validate the effectiveness and superior performance of the proposed method.