Load Torque Research Articles

Dual Model Predictive Control Strategy of Direct‐Drive PMSM Based on Sliding Mode Disturbance Observer

Aiming at the current control steady‐state error caused by sampling delay, parameters mismatch of direct‐drive permanent magnet synchronous motor (PMSM). This paper proposed a method of dual model predictive control (MPC) of direct‐drive PMSM based on sliding mode disturbance observer (SMDO). Deadbeat predictive current control (DPCC) is used for current loop, a SMDO is proposed to observe the system disturbance, the estimation is compensated to DPCC by feedback to decrease the current control steady‐state error. For speed loop, MPC with an internal model control observer (IMCO) can observe and compensate the load disturbance feedforward. The experimental results show that, the dynamic response speed of the proposed strategy is fast, the speed recovery time after sudden load torque is short, and the anti‐load disturbance performance and current tracking performance are effectively improved. © 2024 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC.

Robust passivity-based nonlinear controller design for bilateral teleoperation system under variable time delay and variable load disturbance

Abstract This research focuses on implementing a robust passivity-based nonlinear control method for bilateral/teleoperation systems. The key challenge is addressing communication pathways between the master and slave, control delays, and load disturbances, which can lead to instability and reduced transparency. To tackle these issues, the proposed controller incorporates a second-order super-twisting sliding-mode observer to counteract communication and control delays. A sliding mode assist disturbance observer compensates for load torque variations. The approach aims to ensure stability and transparency by handling time-varying delays. The system model comprises two interconnected direct-drive motors, simulating robotic configurations without a physical robot. The nonlinear controller framework simplifies the complex bilateral control problem, significantly improving stability and transparency performance. Computer simulations with step and sinusoidal inputs demonstrate the effectiveness of the approach, providing a satisfactory level of accuracy and transparency between estimated and actual slave positions, even with varying delays and load variations. The research contributes to control engineering by offering a robust method to enhance bilateral system performance, ensuring stable and transparent communication between the master and slave, particularly suitable for real-time internet-based bilateral control systems.

Analysis on the Dynamic Behavior of Space Shafting under Combined Load

The space shafting is the core component of the momentum exchange attitude control actuator for spacecraft.The dynamic behavior of space shafting has an important impact on the performance of the actuators. Based on the dynamic theory of rolling bearing, this paper presents a dynamic analysis model of space shafting for the interaction between bearing balls and oil-containing nonmetallic cage under combined loads. Also, the accuracy of the analysis model was verified through a high-speed camera system to conduct a cage speed test. In addition, the dynamic behavior of balls and cage under combined loads and the interaction between them is also analysed. The results show that the axial displacements of balls fluctuate periodically under combined loads, and the rotation speeds of balls and cage are easily affected by the load, presenting as the oscillation of speed. Also, the force between balls and cage increases as the load increases. The dynamic behavior of balls and cage could be effectively improved by avoiding excessive torque loads and limiting the axial preload to 40 N. The wear failure caused by unstable operation of bearings cannot be ignored. This model is more practical in completing simulation analysis of different operating conditions and structural parameters of the shafting system. It provides a theoretical reference for the structural design and performance analysis of space shafting.

Dynamic characteristics analysis of gear system with time-varying torque of motor and load based on motor control strategy

Dynamic characteristics analysis of gear system with time-varying torque of motor and load based on motor control strategy

Numerical Investigation of Heat Production in the Two-Wheeler Electric Vehicle Battery via Torque Load Variation Test

Experimental studies were conducted to investigate the effect of varying torque loads on the temperature distribution on the surface of lithium-ion batteries (72 volts–20 Ah) in real commercial two-wheeler electric vehicles as part of our previous research. An electric vehicle engine was installed in a dyno testing laboratory and used as the main load for the battery. Ambient temperature and relative humidity were controlled using an air conditioning system. The test results are presented as surface temperature distributions on each side of the battery at various torque loads. The highest temperature on the battery’s surface was found to be approximately 40 °C at a torque load of 100%. Unfortunately, the heat generated by the battery during testing could not be measured for further research. This paper presents a numerical study of battery heat generation at 100% torque load using Ansys Fluent 2020 R1©. This tool is employed to calculate the heat flux from the battery surface to the ambient air. The CFD tool was initially validated against available experimental data and commonly used correlations for natural convection along a vertically heated wall. Good agreements between the current predictions and experimental data were observed for laminar flow regimes. Convective heat transfer between the battery surface and ambient air was simulated. The results indicate that the commonly used heat transfer correlation for vertical plates accurately predicts the heat transfer rate on the battery surface, and it was found that the heat generation rate is 1199 W/m3.

Theoretical Development and Experimental Evaluation of a Nonlinear Observer for sensorless WECS

This research paper introduces a novel sensorless wind energy conversion system (WECS) with a Vienna rectifiers-based high-gain observer. The main emphasis is on crafting a high-gain observer capable of providing real-time estimates for challenging-to-measure signals like rotor speed and load torque. Addressing the complexities arising from system nonlinearity and high dimensionality, the paper showcases the effectiveness of the proposed observer through simulations and theoretical analysis. Furthermore, an experimental validation on the RealTime Digital Simulator (RTDS) platform validates the observer’s performance and reliability, highlighting its potential for enhancing sensorless WECS technology.

Comparative Investigation of DSP-Based Speed Control of PMSM Using Proportional Integral and Takagi-Sugeno Fuzzy Logic Controller

This paper presents the simulation and experimental results of speed control of a three-phase Permanent Magnet Synchronous Motor (PMSM). The control techniques employed in this work include a Proportional Integral (PI) controller and a Takagi-Sugeno Fuzzy Logic Controller (TS-FLC). While theory and simulation help in predicting the PI controller settings for real drive implementation, further adjustment of the PI controller coefficients is still needed for optimal performance. However, the complexity of PI controller tuning can be overcome by employing a fuzzy logic controller, which is less affected by variations in model parameters and load torque. Two variants of the proposed TS-FLC are implemented: a simple algorithm with 9 rules and a standard algorithm with 49 rules. The drive system utilizes Field Oriented Control (FOC). The control program is developed using the C/C++ programming language and executed on the Texas Instruments TMS320LF28335 Digital Signal Processor (DSP), known for its intelligent motor control capabilities. The drive system evaluation was performed through simulations and experimentation using the MCK28335 professional development kit provided by Technosoft Company. The simulation and experimental results of the proposed controllers are compared under various conditions, including speed reversal and load torque variations.

An Application of Feedback Linearizing Controller with Disturbance Observer for DC Motor Real-Time Speed Control

The main objective of this paper is the hardware implementation of robust speed and torque control of DC motors. The proposed speed controller is a feedback linearizing controller (FLC) with a disturbance observer (DO). The designed control circuit can withstand non-linearities of the system and other unpredictable disturbances. In addition, the exact mathematical modelling of the controller is used and thus the system can be easily reproduced to any higher rating. The converter used to interface the DC motor is a bi-directional H bridge converter that can supply and accept power at any voltage conditions. The developed system is experimentally tested under different case studies of motoring and regenerating conditions. From the results, it is verified that the objective is met, and the designed prototype system can work accurately to follow the speed and load torque. The designed system can be used for variety of industrial applications including electric traction, robotics, and various fixed as well as variable speed electric drives.

Prototype Design and Construction of 450 VA Permanent Magnetic Sync Generator for Vertical Axis Wind Power Generator House Scale with Low Wind Speed

Permanent magnet synchronous generator (PMSG) is a mechanical electrical machine that can convert motion energy into electrical energy which has two main parts, namely a rotor using permanent magnets and a stator without an iron core which the machine uses for low and low rotations. load torque used as a generator. The driving force for Wind Power Plants (PLTB) which we know is alternative and renewable power plants, the energy source is wind which continues to exist and is easily available, another reason for the need to develop permanent magnet generators for PLTB is the reduction of petroleum, other fossil energy, subsidies continue to cut materials fuel oil for power generation which increases the price of electricity per KWH as well as a global commitment to reduce greenhouse gas emissions. the need for electricity for the community and the high price of electricity as well as the difficulty of installing electricity with a capacity of 450 VA, this study aims to make a prototype of a laboratory-scale permanent magnet generator for wind power plants for residential homes that allows it to be placed close to the ground, no need to be directed towards the wind. blowing, can generate electricity with wind speed from 2.5 m/s, easy operation and low cost. The research method in this study is to conduct a literature study, conduct a wind source mapping survey from several sources to obtain wind speed data nationally, design a prototype and design a permanent magnet generator prototype and finally simulation with calculation capacity of the prototype. The design of the permanent magnet generator prototype for the Wind Power Plant has 12 poles with a rotor speed of 500 rpm (revolution per minute) with capacity of 450 VA.

Numerical and analytical models of the mechanism of torque and axial load transmission in a shock absorber for drilling oil, gas and geothermal wells

The paper proposes an improved design of a shock absorber used in drilling deep oil and gas and geothermal wells with polycrystalline diamond compact (PDC) bits. The proposed innovations successfully combat the dangerous phenomenon of self-excited vibrations, which can lead to malfunctions such as stick-slip and whirling of the drilling tool. Most conventional drill shock absorbers are designed to only absorb longitudinal vibrations, which was sufficient when using roller cutter bits for the drilling process. However, the design features of PDC bits and the phenomenon of interaction of their cutters with interlayered rocks during deep drilling impose new requirements on the properties of the drill shock absorber. To protect the downhole tool from abnormal torque values and torque oscillations, it is proposed to equip the shock absorber with a special torque transmission unit in the form of a fourteen-thread self-releasing screw pair. This unit is capable of transforming increases in external torque into increases in the force that loads the elastic element of the shock absorber. The numerical and analytical models of the mechanism of transferring external axial load and torque to the elastic element of the drill shock absorber are constructed. The distribution of contact pressures on the interacting surfaces of the screw pair and the distribution of equivalent stresses in the screw pair parts are analysed. The strength of the proposed drill shock absorber assembly was evaluated using the Huber-von Mises energy criterion. The dependence of the load transmitted to the elastic element of the shock absorber on changes in the external torque and external axial force is investigated. In general, it is determined that the external load is distributed evenly between all turns of the screw pair, and the limit state of the parts of the proposed assembly is not reached even under high-torque operating load. The obtained analytical dependencies will allow to effectively determine the required strength and stiffness of the elastic element of the drill shock absorber at the design stage. The obtained analytical results were verified using a finite element model.

Research on Surplus Force (torque) Control and Compensation of Electro hydraulic Load Simulator

Abstract: The electro-hydraulic load simulator can simulate any force (torque) load required by the loaded object under test conditions, which greatly reduces the equipment development time and cost. However, the process of force loading inevitably creates a surplus force (torque). The existence of surplus force (torque) in the system will seriously interfere with the loading accuracy of the system and even damage the equipment in serious cases. In this paper, based on the research status of the suppression and compensation of the surplus force (torque) in the electro-hydraulic load simulator, the effective control strategies and methods to overcome the surplus force (torque) in the system are summarized. This paper analyzes the generation mechanism of the surplus force (torque), and summarizes the effective strategies to overcome the surplus force (torque) of the system in structural compensation and control compensation. Using the control method to compensate for the surplus force (torque) has the advantages of simple structure, convenient debugging, and strong universality. It is widely used in the electro-hydraulic load simulator to suppress the surplus force (torque). With the development of control theory, more and more control strategies and methods are applied to restrain and compensate for the surplus force (torque) in the electro-hydraulic load simulator, which not only restrains the surplus force (torque) in the system but also improves the loading accuracy and anti-interference. Methods: This paper analyzes the generation mechanism of the surplus force (torque), and summarizes the effective strategies to overcome the surplus force (torque) of the system in structural compensation and control compensation. Results: Using the control method to compensate for the surplus force (torque) has the advantages of simple structure, convenient debugging, and strong universality. It is widely used in the electro-hydraulic load simulator to suppress the surplus force (torque). Conclusion: With the development of control theory, more and more control strategies and methods are applied to restrain and compensate for the surplus force (torque) in the electro-hydraulic load simulator, which not only restrains the surplus force (torque) in the system but also improves the loading accuracy and anti-interference.

An optimized particle swarm optimization algorithm for turbine torque and generator load parameter identification

Hydraulic turbine control system is a complex system with strong nonlinearity and multiple variables. Therefore, in order to better control the turbine system, it is necessary to obtain the parameters of key components. Aiming at the limitation of the traditional particle swarm optimization algorithm in global search ability, mutation operator and dynamic inertia weight coefficient are introduced to enhance the search ability of the algorithm. In addition, in order to further improve the global search performance of the algorithm, this paper combines the optimized particle swarm optimization algorithm with genetic algorithm to form a hybrid parameter identification algorithm. The hybrid algorithm not only uses the fast convergence of particle swarm optimization (PSO), but also uses the global search advantage of genetic algorithm (GA) to realize efficient and accurate identification of turbine torque and load parameters. Through MATLAB2021a/Simulink simulation experiments, the application effect of the algorithm in the identification of turbine torque and generator load parameters is verified. The simulation results show that the optimized particle swarm optimization algorithm has significant advantages in the accuracy and robustness of parameter identification, and the identified parameters have a high degree of fitting with the actual measured torque and speed. This study not only provides a new optimization strategy for the parameter identification of turbine regulation system, but also provides an effective intelligent algorithm solution for the parameter identification of nonlinear system.

Passivity-based Control of PMSM Servo System with Load Torque Adaptation: Theoretical and Experimental Validation

Passivity-based Control of PMSM Servo System with Load Torque Adaptation: Theoretical and Experimental Validation

A suggestion for space harmonic injection into motor current to reduce propeller vibration

Propellers produce fluctuating thrust and torque as they rotate in a non-uniform wake field. They contribute most of the vibration and noise generated by the propeller and can lead to mechanical damage to shafts and bearings. Recently, the demand for electric propulsion ships has increased. As the torque and speed fluctuations are generated in marine propellers, harmonic components in the current and voltage of the propulsion motor occur and lead to increased losses, device degradation, and torque pulsations. In this study, a harmonic injection method is proposed to reduce the impact of motor and mechanical vibration caused by the fluctuating load torque of the propeller. A harmonic component is applied to the current of the motor to generate a motor torque with a different phase of the same magnitude as the variation of the load torque of the motor. In this study, a computational fluid dynamics simulation was performed to obtain the torque of the target vessel, medium range tanker, and a MATLAB Simulink was used to model the motor simulation. It was found that the harmonic injection method can reduce the mechanical torque fluctuation of the motor by 87%.

Identification between broken rotor bars and low-frequency load torque fluctuations in a three-phase induction motor

Identification between broken rotor bars and low-frequency load torque fluctuations in a three-phase induction motor

Hybrid Flatness-Based Control of Dual Star Induction Machine Drive System for More Electrical Aircraft

Abstract This paper develops a precise method control system for tracking control of a power drive system based on a multi-phase machine under motor parameter and load torque variations. By adding a simple feedforward term based on the flatness theory, a conventional flux oriented control (FOC) can be enforced to have a perfect tracking performance under model parameter and load torque variations. Hence, a hybrid flatness-based control (HFBC) technique is applied to the control of a dual star induction machine (DSIM) and compared to a classical vector control strategy regarding tracking behaviour, robustness, and perturbations rejection. Finally, the simulation and experimental results are provided to verify the effectiveness of the proposed HFBC under uncertainties such as motor parameter and load torque variations. Furthermore, an enhancement of the drive system’s control performances is demonstrated by the improvement of the technique of separation of the objectives of tracking and disturbance rejection. The simulation and experimental results are presented, demonstrating the superiority of the HFBC.

Identification between broken rotor bars and low-frequency load torque fluctuations in a three-phase induction motor

Identification between broken rotor bars and low-frequency load torque fluctuations in a three-phase induction motor

Comparative analysis of a supercapacitor and Li-ion battery based electric vehicle

This paper has simulated an Electric Vehicle (EV) in MATLAB/Simulink environment where Supercapacitors (SC) are compared with Li-ion batteries. Simulated EV is tested under both above discussed scenarios for evaluating its performance under certain speed and torque load conditions. The critical aim of the government or any manufacturing company is to reduce the carbon footprint and provide better living conditions for their people. The major step to achieve this aim is to maximize EV usage. Therefore, it can be attained through the implementation of battery energy storage system. This paper has paved the way towards the goal by showing supercapacitors or Li-ion as energy sorage interms of there performances and recharging time. The inhibition of supercapacitors instead of the currently used Li-ion can turn out to be a game changer as it can be reused which decreases the chances of E-wastage but it has certain limitation. Moreover, supercapacitors are known for having high speed of charge (1000 times faster than Li-ion) that increases the efficiency of the EV.

Badania przyczyn niepożądanej synchronizacji prędkości obrotowej silnika z częstotliwością modulacji PWM w układzie napędowym PM BLDC

In a drive system comprising a high-speed PM BLDC motor and an inverter implementing motor phases commutation and phase voltages PWM modulation, a spontaneous synchronisation between the PWM modulation frequency and the motor rotational speed may occur. The drive behaves like an unintended phase-locked loop. The effect distorts mechanical characteristic of the drive by introducing flat segments where the rotational speed remains constant despite changing load torque. It makes the speed-torque relationship discontinuous, nonlinear, and non-unique. The phenomenon is closely related to the problem of phase current and motor torque ripples. The paper presents experimental results recorded with a laboratory test bench for drives for electric power tools where the phenomenon of the parasitic speed locking has been observed. A root cause of this effect is discussed, and the mechanism of unwanted synchronisation is investigated. Several mitigation techniques are proposed and verified with computer simulations.

Enhanced Position Estimation of PMSM Using the Luenberger Observer and PLL Algorithm: Design and Simulation Study

This study proposes an enhanced method for estimating the position of a permanent magnet synchronous motor (PMSM) using the Luenberger observer and phase-locked loop (PLL) algorithm. The main contribution to this research is the use of two low-pass filters (LPF) at the input of the PLL, which results in softer position reconstruction compared with conventional PLL. The proposed method is designed and simulated using the MATLAB/Simulink platform. The performance of the proposed method was evaluated and compared with conventional PLL and PLL with one LPF using several performance metrics such as estimation accuracy, convergence time, and stability. Simulation results show that the proposed method achieves better estimation accuracy and higher stability compared with the other methods. Additionally, the proposed method is robust to various disturbances such as load torque and parameter variations. Overall, the proposed method offers an effective and efficient solution for estimating the position of PMSM in various industrial applications.