Speed Loop Research Articles

Precision Control of Micromechanical Automatic Manufacturing Based on Nanotechnology

Segment precision affects the accuracy level of micro machine manufacturing, only for the linear change is not big, more straight segment control, easy to cause dimensional deviation, so a precision control method of micro machine automatic manufacturing based on nanotechnology is proposed. The white noise is selected as random sequence to eliminate the concentrated trend and high frequency components in the input and output data. The precision control parameters of micromechanical automatic manufacturing are adjusted by setting the current loop, speed loop and position loop. According to the setting results, the contact area of micromechanical automation manufacturing is established in the coordinate system o-xy, and the equivalent curvature radius of the contact surface is calculated. Through coordinate transformation, the pressure distribution in the circular contact area is obtained, and the precision control area model of micromanical automation manufacturing is established. According to the model and the finite element analysis method, the control flow is designed to realize the precision control of the automatic manufacturing of micromachines. The experimental results show that the design method can reduce the precision control error of the automatic manufacturing of micromachines and improve the construction level of micromachines.

Conduction Angle Control of Switched Reluctance Motor

This paper presents a microcontroller based closed loop speed control of Switched Reluctance Motor (SRM) drive powered through Asymmetric Half Bridge Converter (AHBC). Conduction angle control method is adopted for speed control and it is done by adjusting the duty cycle of PWM signal using a potentiometer. The performance comparison of speed control of SRM drive through single switch per phase converter and AHBC is performed with the help of soft chopping in conduction angle control method.

Adaptive Dual Closed Loop Speed Control with Throttle Valve Dynamics for Natural Gas Engine in Range-Extended Electric Vehicles

Adaptive Dual Closed Loop Speed Control with Throttle Valve Dynamics for Natural Gas Engine in Range-Extended Electric Vehicles

Design and implementation of a nonlinear controller and observer for inverter fed permanent magnet synchronous motor drive using dSPACE DS1103 controller board

This paper proposes a control system for the speed control of permanent magnet synchronous motor (PMSM) drive through hardware implementation using dSPACE DS1103 controller board. The proposed control scheme consists of two loops such as the inner current loop and outer speed loop. In the inner current loop a nonlinear full order observer (NFOO) along with the state feedback controller (SFC) is used; whereas in outer speed loop PI controller is used as speed controller. The proposed NFOO estimates all the states of PMSM and fed back to the SFC. A nonlinear controller (NLC) is designed along with SFC, to cancel out the system nonlinearity using the concept of exact feedback linearisation. Also the pole placement technique is implemented in order to shift all the poles to left half of the s-plane resulting the system stable in spite of uncertainties and parameter imperfections. The speed and position information of the PMSM is obtained using an encoder. The proposed control scheme has been extensively simulated under various conditions and verified experimentally through dSPACE DS1103 controller.

Fault-Tolerant Control of Coil Inter-Turn Short-Circuit in Five-Phase Permanent Magnet Synchronous Motor

In the five-phase permanent magnet synchronous motor (PMSM) control system, the torque ripple caused by coil inter-turn short-circuit (ITSC)fault will make the motor performance worse. Due to the existence of the short-circuit current in the faulty phase and the third harmonic component in the permanent magnet flux linkage, the electromagnetic torque will contain even-order ripple components when the faulty phase is removed. Torque ripple also cause speed ripple. In this paper, the repetitive controller (RC) is used to perform proportional gain compensation for speed ripple. By designing the RC and connecting RC and proportional integral (PI) controller in parallel for the speed loop, the torque ripple amplitude can be reduced. It can be seen from the simulation and experimental results that the torque ripple suppression strategy based on RC can effectively suppress the torque ripple under ITSC fault.

Feedback Linearization Based Robust Control for Linear Permanent Magnet Synchronous Motors

In this study, we designed a feedback linearization control strategy for linear permanent magnet synchronous motors (LPMSMs) as well as a robust control mechanism. First, the highly nonlinear system was transformed into an exact linear system by the feedback linearization technique. Then, we designed a robust controller to mitigate the impact of system parameter disturbances on system performance. This novel robust feedback controller can be applied to electromagnetic force, speed and position control loops in linear motors, correct the errors created by uncertainty factors in the entire system in real time, and set the system’s settling time based on the application environment of the plant. Finally, we performed simulations and experiments using a PC-based motor control system, which demonstrated that the proposed robust feedback controller can achieve good performance in the controlled system with robust anti-disturbance control.

Research on brushless DC motor control system based on fuzzy parameter adaptive PI algorithm

As a complex system with multiple variables, nonlinearity, and strong coupling, the BLDCM (Brushless Direct Current Motor) has many problems, such as bad parameter tuning, poor adaptability, low control accuracy, and weak anti-interference ability by using the double closed loop traditional PI (Proportional Integral) control algorithm. In order to obtain good control performance, a fuzzy parameter adaptive PI algorithm based on speed loop was designed by combining fuzzy control with traditional PI control. This paper analyzes the mathematical model and operating characteristics of the BLDCM and designs a fuzzy system that takes the deviation e and deviation change rate ec of the reference speed and feedback speed as input and takes the corresponding PI adjustment parameters as output. The step response of the BLDCM at different reference speeds is analyzed. The variable speed response with the initial speed of 4000 r/min under different control algorithms and the changes in the three-phase current, back electromotive force, and electromagnetic torque in this state are compared. The results show that the designed fuzzy parameter adaptive PI algorithm based on the speed loop can make the motor have a faster response time, a smaller overshoot, and a steady-state error when the motor achieves the stable operation. The proposed algorithm also has better control effect, robustness, and stable operation under variable speed conditions.

Comparison of BPN, RBFN and wavelet neural network in induction motor modelling for speed estimation

ABSTRACT This paper discusses the question of estimating a neural network induction motor speed. The neural network is trained in the relationship between stator currents and rotor speed. Rotor currents and speed are created using MATLAB from simulated model induction motor and from experimental real-time set-up using LABVIEW. With these two data sets, Induction motor is modelled using three neural network architectures, namely BPN, RBFN and Wavelet Neural Network, comparing the performance of each neural model in estimating speed. Results show the neural approach's ability to replace the speed sensor used in the closed loop speed control system to accurately estimate speed.

Robust nonlinear model predictive control for automatic train operation based on constraint tightening strategy

AbstractThis paper studies the problem of automatic train operation (ATO) robust nonlinear model predictive control under considering multiple objectives and constraints. After establishing a nonlinear multipoint model with uncertain bounded disturbance, a robust nonlinear model predictive control algorithm to meet the punctuality of train operation and energy consumption for ATO is proposed based on constraint tightening strategy. Moreover, theoretical analysis of the feasibility and stability for the speed loop system are presented. Then, with the objective of reference electromagnetic torque tracking and low switching frequency, a model predictive direct torque control algorithm with one‐step delay compensation is proposed. Feasibility of the proposed algorithm is ensured by using deadlock prediction method, and convergence analysis of the torque loop is given simultaneously. Lastly, the effectiveness of these two algorithms are verified by numerical simulation.

Maximum power extraction framework using robust fractional-order feedback linearization control and GM-CPSO for PMSG-based WECS

The most important issue in the use of wind energy conversion systems is to ensure maximum power extraction in terms of efficiency. Therefore, maximum power point tracking algorithms are as important as the maximum power point tracking controller. In this study, maximum power extraction frameworks operating the state-of-the-art optimization methods are presented for permanent magnet synchronous generator–based wind energy conversion system. These frameworks consist of a Gauss map–based chaotic particle swarm optimization and a hybrid maximum power point tracking approach that combines feedback linearization technique with fractional-order calculus. The feedback linearization control strategy can fully decouple and linearize the original state variables of the nonlinear system and thus provide an optimal controller crossing wide-range operating conditions. The objective is to maintain the tip speed ratio at its optimal value, which implies the use of a rotational speed loop. The method is based on the feedback linearization technique and the fractional control theory. Gauss map–based chaotic particle swarm optimization, which is a remarkable and recent optimization technique, is utilized to achieve optimum coefficients to efficiently ensure the maximum power point tracking operation in here. A simulation study is carried out on a 3-kW wind energy conversion system to show the effectiveness of the proposed control scheme.

Multivariable generalised predictive control with measurement noise rejection and speed ripple mitigation for PMSM drives

Generalised predictive control (GPC) is known for its good dynamic performance and long prediction horizon, but the performance can be severely deteriorated when measurement noises exist due to the wide control bandwidth of GPC. Meanwhile, the unmodelled periodic disturbances can cause ripples to the output variables. In this study, a practical permanent magnet synchronous motor (PMSM) drive system with speed measurement noise and periodic disturbances is considered, for which a novel multivariable GPC method is proposed to achieve both good dynamic performance and speed ripple mitigation. The proposed method has a simple structure, since the traditional cascaded speed and current control loops are replaced by a non-cascaded one. To reject the measurement noise without jeopardising the system stability, an internal low-pass filter is embedded in the GPC. Meanwhile, external resonant loops are added to the GPC to mitigate the low-order speed ripples caused by the periodic disturbances. Furthermore, a deadbeat-based current constraint method is proposed to avoid overcurrent during transient processes. Theoretical stability analysis of the proposed method is presented. Experimental results show that the proposed method has good steady-state and dynamic performances, including measurement noise rejection and speed ripple mitigation.

Performance Analysis of BLDC Motor Drive using Enhanced Neural Based Speed Controller for Electric Vehicle Applications

This paper deals with Brushless DC (BLDC) motor drive mathematical model with hysteresis current controlled based Voltage Source Inverter (VSI) which operates using Neural Network (NN). The developed simulation model is applied with the artificial neuro speed controller which is based on Least Mean Square (LMS) and Adaptive Linear Neuron (ADALINE) to improve the performance of BLDC motor drive. Under dynamic operating conditions, the NN speed controller is trained by the data obtained from closed loop speed controller of BLDC motor drive system. The developed conventional and proposed simulation models are simulated using MATLAB/Simulation software. The proposed neural based speed controller is important for tracking of motor speed as well as torque with their reference values with minimum transient time. In this paper ADALINE network model is developed for update of weights in NN. Here, a comparative study has been done for PI and NN controller for BLDC drive. The simulation results show that the NN based speed controller is more effective controller compared to classical PI based speed controller during most of the dynamic operating conditions.

Mitigating the Torque Ripple in Electric Traction Using Proportional Integral Resonant Controller

There is increasing popularity of using permanent magnet (PM) machines in vehicle propulsion systems. Due to the pre-excitation of PM, the machines could offer higher efficiency and torque density. However, their inherent torque ripple could be problematic for electric vehicles (EVs) due to low damping of torsional vibration which may affect passenger comfort. This can prohibit the use of PM machines to improve vehicle energy efficiency. This paper presents the application of resonant control (RC) to suppress the impact of the PM torque ripple, which aims to reduce the vibration of a vehicle. A prototype PM machine and driveline have been fitted to a light-duty off-road vehicle. Firstly, the drivetrain frequency response was analyzed. The main source of the vibration is identified as the 24th harmonic torque ripple of the 12-slot/8-pole PM machine, which originates from the cogging torque and air-gap flux harmonics. The vibration becomes more severe when the torque ripple frequency is close to the natural frequency of the drivetrain. Then, the RC in conjunction with PI controller (PIR) was introduced to be used at the outer speed loop, so that an accurate current reference signal can be generated for the inverter to mitigate the speed ripple. When compared to the conventional Proportional-Integral (PI) controller, PIR controller has demonstrated over 80% reduction in speed ripple, even when the torque ripple frequency is close to the natural frequency of the vehicle.

The Fuzzy PI Controller for PMSM’s Speed to Track the Standard Model

This paper proposes a fuzzy PI controller to control the speed of a permanent magnet synchronous motor (PMSM). The structure of the system includes the speed loop controller (SLC) and the current loop controller (CLC). The speed loop controller is the fuzzy PI and standard model (SM). The CLC includes vector control and the space vector pulse width modulation (SVPWM). It compiles two closed-loop control systems for the PMSM. This research uses a very high-speed integrated circuit hardware description language (VHDL) to implement the proposed algorithm and embed it into Matlab/Simulink for simulation. Based on the PMSM parameter, this article tests the controller’s correctness with some of the load cases by changing the combined inertia and viscous friction of rotor and load. After success in simulation, the system is tested again by experiment on the FPGA kit. The simulation and experiment results show that when the load changes, the PMSM speed is still stable. The novelty of this research is that it compares two kinds of controllers between simulation and experiment results.

AUTOMATED CONTROL SYSTEM OF THE SCAN ANTENNA SYSTEM

Based on the method of structural schemes, the control system of the scanning antenna system is synthesized, which is a special case of the tracking system, which, based on the given coordinates, controls the mismatch between the necessary and current values of the azimuth and elevation angles. An important feature of scanning systems is the constant movement of actuators when performing tasks of the intended purpose. Therefore, the nonlinearity of the elements of the navigation system can lead to a significant deterioration in the quality of the scan tasks. The article substantiates the block diagram of scanning on one channel, its mathematical description is determined. At the first stage, an analysis of the stability of a functionally minimal system was carried out. The need was identified for integrating the circuit with a sequentially connected speed controller of proportional-integral-differential action and a feedback signal taken from the tachometer on the axis of the engine. The speed loop was modeled to analyze its stability and ability to maintain its properties when the parameters deviate from the calculated values or the controller parameter settings are varied. A general scheme of the scanning system was built into which a nonlinear element was introduced. As a nonlinear element, a simplified model of a fiber-optic gyroscope with a deadband was chosen. In order to verify compliance with the requirements in transitional and established operating modes, as well as to evaluate the error of the system when exposed to real effects, a model experiment was conducted. The simulation results showed the high quality of the synthesized system. The control errors were investigated in the absence of a nonlinear element, as well as in its presence with a variation in the value of the width of the deadband. It is determined that high values of the width of the dead zone can lead to a breakdown of control, which must be taken into account when substantiating the requirements for such systems.

RETRACTED ARTICLE: Modified SVPWM based three phase to nine phase matrix converter for nine phase induction motor with closed loop speed control

A new design procedure is presented in this paper to simulate the implementation of 3–9 Ф power conversion using matrix converter whose output is fed to the Induction motor to control speed under closed loop configuration. Using mathematical derivations, the converter is modeled and its performance is evaluated using nonlinear load. The overall matrix converter circuit is simulated in MATLAB. The numerical equations which relate the input and outcome of the 9Ф matrix converter is executed by utilizing Simulation blocks. The duty cycle of the bidirectional switches is estimated using PI/PR/Fuzzy controller for optimum voltage transfer ratio. Due to the low on-state resistance and conduction losses, and better power handling capacity in addition to the ability of switching at higher voltages at frequency below 20 kHz, the power circuit was implemented using bidirectional IGBT switches to achieve high speed switching operation (10 kHz) and to minimize on state conduction misfortunes with less THD. The duty cycle of the bidirectional switches are controlled by the space vector PWM controller. Finally the performance of the controllers is compared with regards to THD.

Control optimization of electromechanical systems by fractional-integral controllers

The object of research in the work is electromechanical systems, a characteristic feature of which is the presence of significant power dependence in the mathematical description. Because of this, problems arise when choosing the structure and parameters of controllers. In particular, in a DC motor with series excitation, a switched reluctance motor and electromagnetic retarders, saturation of the magnetic system in static and dynamic modes can occur. The apparatus of fractional-integral calculus used in the work allows us to describe such nonlinear objects with high accuracy by linear transfer functions of fractional order. So, when approximating the anchor circuit of a DC motor with series excitation by a fractional transfer function, the smallest standard error was obtained. The combination of a conventional PID controller with fractional integral components of the order of 0.35 and 1.35 ensured the best quality of the transient process - the current reaches the set value as quickly as possible without overshoot. Secondly, the switched reluctance motor, in the model of which it is necessary to take into account the power dependences, is described by the aperiodic function of the order of 0.7 when describing the transient processes of the speed during a voltage jump. From the family of controllers studied, the traditional PI controller with additional fractional-integral components of the order of 0.7 and 1.7 ensured the astaticism of the speed loop of the order of 1.7 and the smallest overshoot. Thirdly, the electromagnetic retarders of the driving wheels of a car, used to tune the internal combustion engine, are also most accurately described after testing by the fractional transfer function. Using the PIDIγIµ controller, which ensured closed loop astaticism of the order of 1.63, stabilization of the rotation speed of two wheels without out-of-phase oscillations and the accurate development of a triangular tachogram were achieved. Thus, thanks to the apparatus of fractional-integral calculus, a more accurate identification of object parameters is provided, the mathematical description is reduced to linear transfer functions of fractional order. And in closed systems it is possible to ensure astaticism of fractional order 1.3–1.7 and to achieve a better quality of transient processes than using classical methods.

A new short-time high-overload BLDC driving system based on electronic flywheel and time-division switching control

Most of the existing (BLDCM) brushless dc motor drive systems are designed with the traditional drive scheme for long-time operation. For short-time and heavy-duty applications, there are problems of energy consumption, large volume, heavyweight and high-cost. In this paper, a new short-time high-overload BLDCM drive system based on "electronic flywheel" and time-division switching control is proposed, which includes three core contents: a crushing chamber based on combined cutter head, an energy storage device based on an "electronic flywheel" and high overload factor BLDC using a new calculation method of capacitance and a speed control system based on time-division switching control of the speed loop and the current loop. To prove the effectiveness of the proposed scheme, a kitchen garbage processor is developed and tested. The results show that the "electronic flywheel" energy storage driving device designed in this paper is able to provide most of the energy required in the heavy-duty driving process. The designed time-division switching control scheme can well meet the control requirements for the short-time heavy load drive of the kitchen waste processor. Compared with the traditional long-time rated load drive scheme, the proposed system has the advantages of energy-saving, small volume, lightweight and low-cost.

Novel Efficacious Utilization of Fuzzy-Logic Controller-Based Two-Quadrant Operation of PMBLDC Motor Drive Systems for Multipass Hot-Steel Rolling Processes

This study investigates the rough steel-rolling process, which requires repeated and rapid bidirectional hot-rolling operations and proposes a fuzzy-logic-controller-based brushless electric DC (BLDC) motor drive system for the same. We present a modeling of the hot-steel rough-rolling process using a set of metallurgical parameters and mechanical equations based on their operating conditions, specific features and characteristics, all obtained from actual data. The above equations and related parameters were modeled in MATLAB/Simulink schematic under variations in temperature and slab thickness corresponding using three different hot-rolled (HR) steel specimens. This led to the creation of a pair of speed and torque- profiles with alternate polarities for successive passes covering the entire rolling process for each steel specimen. A fuzzy logic controller utilized the above profiles on the motor shaft by incorporating speed and current feedback loops to attain reference speed and calculation of instantaneous stator currents of the BLDC motor with respective phase sequences, so as to satisfy the torque-profile. Simulation results showing the detailed performance of the drive system are presented. Further, experimental work on a BLD-motor-drive system is presented, along with loading arrangements and an arm controller embedded with control algorithm for the multi-loop feedback system used for the closed loop speed control. The efficacy of the new applications proposed in this study for the first time can be seen from the validation of the results from the BLDC motor with its fuzzy-based controller in terms of simulation and hardware, thereby serving to be an attractive alternative to conventional induction motor drive systems for steel rolling.

Variable pitch control on direct-driven PMSG for offshore wind turbine using Repetitive-TS fuzzy PID control

Abstract In this paper, the control strategy of the generator side of the direct-driven permanent magnetic synchronous generator(PMSG) system is investigated for Offshore Wind Turbines(OWTs). A hybrid control method that combines a repetitive control and T-S fuzzy PID control is proposed to stabilize the output power. For the current and speed loops of a direct-driven PMSG system, Proportional-Integral(PI) control design based on internal model theory is used for the current loop and the speed loop adopts T-S fuzzy PID control scheme. Furthermore, two wind speed sequences are used to simulate and analyze the proposed system. The proposed hybrid control strategy is evaluated through numerical simulations that incorporate a realistic model of the direct-driven PMSG, which is built in MATLAB/Simulink environment.