High Dynamic Performance Research Articles

A series electric hybrid wheel loader powertrain with independent electric load-sensing system

Electric hybrid powertrain is a promising way for wheel loader electrification. However, the widely used centralized load-sensing working hydraulic system has low efficiency with imbalance load. A novel electric hydraulic system configuration making good use of the electric drive is needed. An independent electric load-sensing hydraulic system for series hybrid wheel loaders is proposed in this study. The lift/tilt functions are powered by speed-controlled fixed displacement pump and controlled by proportional control valves. The independent electric load-sensing hydraulic system eliminates the system inherent power losses of the multi-actuator hydraulic system and combines the high efficiency of variable speed fixed displacement pump and high dynamic performance of valve control. Simulation study on energy efficiency comparison among the proposed powertrain, the existing hybrid powertrain and the non-hybrid powertrain is carried out to check its potential on fuel saving. Results show that the independent electric load-sensing system improves the working hydraulic system efficiency from 34.0% to 54.9% compared to the centralized load-sensing system. The proposed hybrid powertrain saves 11.8% of the fuel consumption compared to the existing hybrid solution, and 41.9% lower than non-hybrid powertrain.

Evaluation of intelligent PPI controller for the performance enhancement of speed control of induction motor

Induction motor control for high dynamic performance industrial applications is often difficult due to parameters sensitivity and its non-linearity. Through independent manipulation of the flux and torque producing components, Field Oriented Control (FOC) methodologies have been used to improve dynamic performance, widen speed range, and torque/flux quality. Studies have shown that the Parallel Proportional Integral (PPI) compensation method produces responses of higher quality than the traditional cascaded Proportional Integral (PI) type though tuning gains for PPI controller is time consuming and inaccurate. In this research work, modeling of control strategy for Induction motor and tuning of four parameters (Ki, Ki1, Kp, Kp1) of PPI controller at the outer speed control loop have been conducted using GA and PSO algorithms. The speed and torque responses' performances of the proposed controller, PPI-PSO and PPI-GA, have been contrasted with each other. For simulation, SIMULINK and a programming environment of a MATLAB software were employed. The simulation result illustrated that PSO based tuning out performs the GA based tuning in terms of dynamic speed response, torque quality and disturbance rejection capability in the newly control mechanism. Although the speed trajectory tracking performance of both the controllers presented in this study is comparable, comparatively low dynamic performance was found for PPI-GA controller at both high and low speed tests inside the same search space. The PPI-PSO controller yields an optimal result having 0.270 % overshoot, a settling time of 8.185 s, and a rise time of 8.037 s in comparison with PPI-GA controller which exhibits overshoot of 0.640 %, a settling time of 9.596 s, and a rise time of 8.615 s with high-speed trajectory tracking test.

High dynamic separation performance of metal–organic frameworks forD2/H2: Independent or competitive adsorption?

AbstractMost traditional D2/H2separation techniques are energy‐intensive with low efficiency. Metal–organic frameworks (MOFs) provide a promising solution for D2/H2separation due to their excellent chemical and structural characteristics. Here, machine learning‐assisted high‐throughput computational screening was employed to identify the high‐performance MOFs for the dynamic D2/H2separation. Extensive data analysis reveals that there were two adsorption behaviors in the optimal MOFs, independent adsorption and competitive adsorption, and the independent adsorption was favorable for the preferential adsorption of D2. To quantify these two adsorption behaviors, we introduced and defined overlap degree (OD) and independence degree (ID), and developed a software for the rapid assessment of OD/ID. After batch simulation of the breakthrough curves of 2000 optimal MOFs, ~80% MOFs exhibited independent occupancy, confirming its contribution to good dynamic separation capabilities. This work provides a new idea for designing MOFs with independent adsorption behavior to improve the dynamic separation performance of hydrogen isotopes.

Nonlinear control of permanent magnet synchronous generators (PMSG) using feedback linearization

This paper presents nonlinear control of permanent magnet synchronous generators using feedback linearization. Permanent-magnet synchronous generators (PMSGs) are commonly used for small variable-speed wind turbines to produce highefficiency, high-reliability, and low-cost wind power generation. To eliminate the effects of nonlinearity caused by magnetic saturation, an input–output feedback linearization technique is applied to design the high-performance nonlinear current controllers. With this nonlinear control scheme, output voltage responses become faster than those in cascade control structures. Thus, the size of the output filter capacitor can be much reduced since fast voltage control is feasible. As with usual PWM power converters, in addition, the input current is regulated in a sinusoidal waveform. The proposed control scheme provides the wind generation system with the maximum efficiency and high dynamic performance.

Extended State Observer-Based Predictive Current Control for Dual Three-Phase PMSM with High Dynamic Performance

Model predictive controllers are widely discussed in the field of dual three-phase permanent magnet synchronous motor control. However, conventional predictive current controllers usually suffer from parameter inaccuracies or model uncertainties, resulting in prediction errors and deterioration of control performance. Therefore, in this paper, an extended state observer-based (ESO) model predictive current controller is proposed to effectively improve the dynamic performance of the motor and its robustness to parameters or disturbances. Parameter inaccuracies or model uncertainties are considered to be lumped disturbances and expressed in the modified mathematical model of the motor. Then, with the designed observer estimating the external disturbances in real time, the prediction error is compensated and corrected periodically. Additionally, the parameter design method of the observer is presented to simplify the controller design. Finally, comparative experiments are implemented to sufficiently demonstrate the effectiveness of the proposed method for dynamic performance improvement as well as for parameter robustness. The results show that the proposed method takes only 17μs of computation time with a closed-loop bandwidth of 1839rad/s. In addition, the maximum d-axis following error of the proposed method is only 0.10A in the load dynamics experiments, which is a significant improvement compared to the 0.79A of the traditional proportional-integral controller.

Pi And Fuzzy Logic Controlled Multiple Lift-Push-Pull Switched Capacitor Luo Converter

This study shows a simulation using PI and fuzzy logic controllers for a newly constructed elementary P/O push-pull switched capacitor Luo converter circuit. This incorporates both voltage lift and switched-capacitor technology. Power electronic converters' dynamic behavior becomes quite non-linear due to their time-varying and switching nature. Fuzzy logic controllers can be utilized as feedforward controllers for power electronic converters because conventional controllers are unable to provide high dynamic performance. By taking repeated measurements of the converter output voltage at specific points during a conduction period, the Control algorithm is created in this study to ensure tracking of the reference voltage and rejection of system disturbances. The main aim is a simulation of PI and Fuzzy logic controls using MATLAB/ Simulink software to evaluate the controller’s performances. The simulation results show Fuzzy controller performs effectively for the preferred converter.

Research on characterizing the high dynamic performance of distributed FANETs

Distributed Flying Ad-Hoc Networks (FANETs) have been widely used in collaborative reconnaissance, situation construction and other scenarios. Due to malicious damage, complex electromagnetic interference, and rapid movement of UAV nodes during flight, distributed FANET have high dynamic characteristics. However, most researches on the characterization of network dynamics cannot fully consider the influence of various factors, such as protocol self-interference. In this paper, by comprehensively considering the effects of node damage, channel fading, protocol self-interference and other factors, based on HCPP model, Weibull distribution model and other theories, we establish link outage probability of network model to characterize link randomness and high dynamicity. On this basis, link entropy rate and topology entropy rate model are established to characterize the high dynamic performance of distributed FANETs.

Dynamic Performance Improvement of Wound Rotor Synchronous Starter/Generator System Based on PWM Rectifier

This paper proposes an active field current tracking (AFCT) control strategy for pulse width modulation (PWM) rectifier, which can remarkably enhance the system’s dynamic performance of wound rotor synchronous starter/generator (WRSSG) system when the load changes. WRSSG system uses a PWM converter in the aero-engine starting process and can reuse the power circuit as a PWM rectifier for high-voltage direct current (HVDC) power generation, thus simplifying the system structure, volume, and weight. The mathematic model of WRSSG system with PWM rectifier is introduced. Based on the system model, the PI controller of armature current loop is designed. The nonlinear PI controller of excitation voltage loop is also illustrated. A 15kW WRSSG system based on PWM rectifier is implemented. The AFCT control strategy and its high dynamic performance are verified by experiments. The simple system structure and distinguished dynamic performance of PWM rectifier with AFCT control can make the WRSSG system more competitive in aircraft applications.

Contact force regulation in physical human-machine interaction based on model predictive control

AbstractWith increasing attention to physical human-machine interaction (pHMI), new control methods involving contact force regulation in collaborative and coexistence scenarios have spread in recent years. Thanks to its internal robustness, high dynamic performance, and capabilities to avoid constraint violations, a Model Predictive Control (MPC) action can pose a viable solution to manage the uncertainties involved in those applications. This paper uses an MPC-driven control method that aims to apply a well-defined and tunable force impulse on a human subject. After describing a general control design suitable to achieve this goal, a practical implementation of such a logic, based on an MPC controller, is shown. In particular, the physical interaction considered is the one occurring between the body of a patient and an external perturbation device in a dynamic posturography trial. The device prototype is presented in both its hardware architecture and software design. The MPC-based main control parameters are thus tuned inside hardware-in-the-loop and human-in-the-loop environments to get optimal behaviors. Finally, the device performance is analyzed to assess the MPC algorithm’s accuracy, repeatability, flexibility, and robustness concerning the several uncertainties due to the specific pHMI environment considered.

Design of Airborne Radar Servo Control System

The brushless DC motor is driven by a square wave. Compared with the sinusoidal synchronous motor, the control is simple. The airborne radar servo control system described in this paper uses a brushless DC motor drive, PWM control, and angular position. The speed detection feedback loop is composed of a brushless resolver and a resolver for digital converters. The control system adopts the current, speed, and position closed-loop design. The design simulation is carried out by using MATLAB/Simulink to guide the control system design. The system design uses PID incremental control and an integral separation control algorithm. Through the rational design of software and hardware, the airborne radar servo system has achieved high dynamic and static performance, which meets the performance requirements of the airborne radar system.

High-Performance Induction Motor Speed Control Using a Robust Hybrid Controller With a Supertwisting Sliding Mode Load Disturbance Observer

To enhance the speed control performance of a three-phase induction motor (IM) controlled by the vector control strategy, a new design of a hybrid controller (HC) is proposed based on the super-twisting algorithm (STA) and fuzzy approach. STA is chosen for its ability to decrease the ingrained chattering phenomenon in the classical sliding mode control (SMC) with maintaining tracking precision and robustness. Nevertheless, the control gains included in the control law have an evident impact on suppressing the chattering phenomenon and increasing the system's dynamic response speed. Therefore, firstly, a robust HC based on the fuzzy logic control (FLC) approach that operates as a fuzzy supervisor to on-line self-tune the value of the gains according to the system states is suggested to achieve high dynamic performance and limit the chattering effect. Secondly, to enhance the disturbance refusal capability, a super-twisting sliding mode load disturbance observer (STSMLDO) is developed to estimate the load torque disturbances. Then the estimated disturbance is introduced into the equivalent control law. Subsequently, the system stability is verified by the Lyapunov theorem. Finally, the superiority of the proposed scheme is validated through comparison with the advanced and traditional controllers in simulation and experimental studies.

A Novel Closed-Loop Structure for Drag-Free Control Systems with ESKF and LQR.

Space-borne gravitational wave detection satellite confronts many uncertain perturbations, such as solar pressure, dilute atmospheric drag, etc. To realize an ultra-static and ultra-stable inertial benchmark achieved by a test-mass (TM) being free to move inside a spacecraft (S/C), the drag-free control system of S/C requires super high steady-state accuracies and dynamic performances. The Active Disturbance Rejection Control (ADRC) technique has a certain capability in solving problems with common perturbations, while there is still room for optimization in dealing with the complicated drag-free control problem. When faced with complex noises, the steady-state accuracy of the traditional control method is not good enough and the convergence speed of regulating process is not fast enough. In this paper, the optimized Active Disturbance Rejection Control technique is applied. With the extended state Kalman filter (ESKF) estimating the states and disturbances in real time, a novel closed-loop control structure is designed by combining the linear quadratic regulator (LQR) and ESKF, which can satisfy the design targets competently. The comparative analysis and simulation results show that the LQR controller designed in this paper has a faster response and a higher accuracy compared with the traditional nonlinear state error feedback (NSEF), which uses a deformation of weighting components of classical PID. The new drag-free control structure proposed in the paper can be used in future gravitational wave detection satellites.

Artificial intelligence based optimal coordination of directional overcurrent relay in distribution systems considering vehicle to grid technology

Optimal coordination of overcurrent relays has become a major challenge in power distribution systems due to the increasing participation of distributed generation (DG) and electric vehicle (EV) charging stations, especially vehicle-to-grid (V2G) technology. This paper proposes a novel approach for optimal coordination of directional overcurrent relays (DOCRs) to achieve the minimum operating time and obtain optimal tuning in terms of time dial setting (TDS) and pick-up current (IP) considering V2G integration. The optimization was conducted using three different Artificial Intelligence (AI) techniques: grey wolf optimization (GWO), cuckoo search (CS), and Hunger Games Search (HGS), and was performed on two systems: IEEE 33-bus system and a local grid located in El-Shorouk City–district#8 (ShC-D8), Cairo, Egypt. The proposed methodology is constructed and validated on ETAP and MATLAB software packages. The simulation results demonstrate that the proposed optimization techniques provide high dynamic performance and accurate coordination of DOCRs. The results show that HGS achieves the minimum operating time of all overcurrent relays as compared with GWO and CS. The effect of V2G integration on the coordination methodology is also considered. The proposed approach provides a significant contribution to the field of power system protection and can help improve the reliability and efficiency of power distribution systems with V2G integration.

Design and Experiments of Electro-Hydrostatic Actuator for Wheel-Legged Robot with Fast Force Control Response

The wheel-legged robot combines the functions of wheeled vehicles and legged robots: high speed and high passability. However, the limited performance of existing joint actuators has always been the bottleneck in the actual applications of large wheel-legged robots. This paper proposed a highly integrated electro-hydrostatic actuator (EHA) to enable high-dynamic performance in giant wheel-legged robots (>200 kg). A prototype with a high force-to-weight ratio was developed by integrating a micropump, a miniature spring accumulator, and a micro-symmetrical cylinder. The prototype achieves a large output force of more than 9400 N and a high force-to-weight ratio of more than 2518 N/kg. Compared with existing EHA-based robots, it has a higher force-to-weight ratio and can bear larger loads. A detailed EHA model was presented, and controllers were designed based on sliding mode control and PID methods to control the output position and force of the piston. The model’s accuracy is improved by identifying uncertain parameters such as friction and leakage coefficient. Finally, both simulations and experiments were carried out. The results verified the fast response of force control (step response within 50 ms, the force tracking control frequency about 6.7 Hz) and the developed EHA’s good potential for future large wheel-legged robots.

PERFORMANCE ANALYSIS AND SPEED CONTROL USING INDIRECT VECTOR CONTROLLED FOR INDUCTION MOTOR DRIVES

This paper presents the speed control scheme of an indirect vector-controlled induction motor (IM) drive. PWM controlling scheme is based on Voltage source inverter type space vector pulse width modulation (SVPWM) and the Conventional-PID controller or Fuzzy-PID controller is employed in closed-loop speed control. Decoupling of the stator current into torque and flux producing (d-q) current components model of an induction motor is involved in the indirect vector control. The torque component Iq current of an IM is developed by an intelligent-based Fuzzy PID controller. Based on settling time and dynamic response the performance of the Fuzzy Logic Controller is compared with that of the PID Controller to sudden load changes. It provides better control of motor torque with high dynamic performance. The simulated design is tested using various toolboxes in MATLAB. Simulation results of both controllers are presented for comparison.

Мокрій Т. Ф., Малишева І. Ю. , Лапіна Л. Г., Пасічник С. С. Взаємодія з рейками коліс пасажирського вагона з новим профілем ободу ІТМ-73EP в криволі-нійних ділянках колії

Speeding up the integration of Ukraine into the European railway transportation is an important task in the current development of the Ukrainian railway transport. Currently, the most effective way to travel across borders between countries with different track gauges is the use of gauge-changeable wheelsets. Continuous traffic on the Ukrainian (1520 mm gauge) and European (1435 mm gauge) railways calls not only for gauge changing facilities, but also for the compatibility of the wheel-rail contact pair on both railways: R65 rails and a cant of 1/20 in Ukraine and UIC60 rails and a cant of 1/40 in Europe. At the Institute of Technical Mechanics of the National Academy of Sciences of Ukraine and the State Space Agency of Ukraine, a new wear-resistant wheel profile, ITM-73ER, was proposed. As predicted, its use in passenger cars will offer dynamic stability and a high dynamic performance throughout the range of operating speeds on the Ukrainian and European railways and acceptable indices of wheel – unworn rail interaction on both railways. In service, the shapes of the wheel and rail contact surfaces change due to wear, especially in curves. Because the Ukrainian and European railways mostly use wheel and rail profiles of their own, the use of the new wheel profile may impair the wheel–rail interaction process, enhance wheel flange wear, and shorten the wheel life. The goal of this work is to study the effect of the in-service rail head shape change in curves of the Ukrainian and European railways on the wheel–rail interaction indices of a passenger car with ITM-73ER profile wheels. The head shapes of outer rails of the Ukrainian and European railways’ circular curves were predicted for a side flange wear changing from 0 to 8 mm in 2 mm increments. The calculations were made for two circular curves of radius 300 m with UIC60 rails and a cant of 1/40 (Europe) and R65 rails and a cant of 1/20 (Ukraine). To speed up the prediction, it was assumed that the curves were traveled by four-axle fully loaded freight cars, which maximizes the rail wear. The freight car wheels were assumed to be unworn and machined to the S1002 profile (for the European railways) and to the standard profile specified by the Ukrainian State Standard GOST 10791:2016 (for the Ukrainian railways). Using the computed head shapes of R65 and UIC60 rails differing in wear degree, a study was conducted into their effect on the wheel–rail pair strain and stress field and the dynamic indices of car–track interaction for passenger cars with ITM73-ER profile wheels negotiating a circular curve of radius 300 m. It was shown that the use of the ITM-73ER wheel profile in passenger cars will offer improved indices of car–track interaction, for worn rails too, both on the Ukrainian railways and in the combined operation on the Ukrainian and European railways.

Highly Efficient Three-Phase Bi-Directional SiC DC–AC Inverter for Electric Vehicle Flywheel Emulator

Flywheels are nowadays a solution for the dynamic charging of electric vehicles since they act as transient energy storage. The need for a top efficient reversible power converter for the flywheel system is crucial to assure high dynamic performance. The paper presents the design of a 50 kW highly efficient reversible three-phase DC–AC inverter involving the most recent silicon carbide metal oxide semiconductor field effect transistors, and its experimental validation on a home-made emulator. Highest efficiency in reversible mode, compactness, and thermal enhancement are the targeted objectives that have been achieved. The power converter prototype evaluated on an original pulse width modulation testing-bench is able to emulate the working of the flywheel system. High frequency pulse width modulation switching, speed cycle operating, and thermal losses are evaluated. In addition, an efficiency above 99% for the converter has been attained, enabling robust functioning of the flywheel system emulator to perform specific charging profiles for electric vehicles.

Quantitive Harmonic Analysis and Force Ripple Suppression of a Parallel Complementary Modular Linear Reluctance Machine

Considering the fluctuating price of permanent magnet, magnetless machine is a new trend in development. Variable reluctance linear machines (VRLM) with simple structure, good robustness, and high dynamic performance, is one of the potential candidates for linear direct-drive wave energy conversion (WEC) application replacing PM-excited linear machine. To ameliorate the fault-tolerance performance of VRLM, the researchers have come up with modular or segmented design, denoted as modular variable reluctance linear machines (MVRLM) However, suffering from large thrust ripple, the design of MVRLM still needs to be improved. To relieve the force ripple of MVRLM, a novel H-shaped modular variable-flux linear reluctance machine (HMVF-LRM) is proposed in this paper. The principle of force ripple suppression by using parallel-complementary structure is analyzed deeply. In this paper, the analytical calculation of induced voltage is developed quantitively with equivalent magnetic circuit method (EMC) and harmonics analysis. Then the design mechanism of HMVF-LRM is illustrated. Further, the performance and fault-tolerant capability of the proposed machine are simulated and evaluated by finite element analysis (FEA), and the prototype is tested to verify the effectiveness of the machine design.

Design and analysis of high dynamic actuator and implementation on quadruped robot

Legged robot research is increasingly pursuing higher speed and higher dynamic manoeuvrability under higher load conditions, however, it poses more stringent challenges to the design of actuator. Under the constraints of actual size and weight restrictions, designing actuators that meet the requirements of high dynamic performance has become the pursuit of many robot designers, and has even become a key factor to limit and constrain the robot’s capability boundary. This paper takes the quadruped robot as the research object, and focuses on analysing the technical requirements of actuators under various gaits and working conditions, A 3-DOF pseudo-direct-drive actuator configuration scheme based on axial magnetic field is proposed. Under the control of the designed force-position hybrid control strategy, the test results of actuator and robot prove that the designed scheme can meet the high mobility with dynamic locomotion capability of the robot.

Comparative Stability Analysis of Synchronous Reference Frame Current Controllers Operated at High Fundamental Frequency

Synchronous reference frame (SRF) proportional-integral (PI) current controller (CC) is the most well-established solution for current regulation in AC machine drives and grid-connected voltage source converters. The design of high dynamic performance current control loop has several challenges in high-speed and high-power applications due to the effects of controller gain’s selection, non-linearities, parameters variations, disturbances, digital implementation, and time delays. These become more significant due to high operating frequencies, which severely degrade dynamics and stability of the current control system. Various structures of SRF PI CCs have been reported in the literature. However, the aforementioned effects on the dynamics at high frequency operation have not been thoroughly addressed. Therefore, a comparative analysis of different SRF PI CCs’ structures is proposed in this paper, which addresses the design principles and gains’ selection while also taking into account the heavy computational burden and PWM delays. Additionally, the paper thoroughly analyzes and evaluates the dynamics and stability of the system operating at high fundamental frequencies. The advantages and limitations of each SRF PI CC scheme are studied and reported. The performance of the SRF PI CCs is comprehensively tested to demonstrate the analytical outcome of this study.