Outer Speed Control Research Articles

BELBIC Tuned PI Controller Based Chopper Driven PMDC Motor

In orthopaedic surgeries, permanent magnet DC motors are used to drill the bone and fix the screws. The Motor drive employs an inner current and outer speed control loop with a conventional or modern controller. To enhance the performance of the drive, this paper proposes a Brain Emotional Logic Based Intelligent Controller based chopper drive. The proposed drive scheme has been simulated using Matlab/Simulink and physically realized for validation. A comparative analysis has been made between the conventional PI controller based drive and the proposed system in order to prove that the proposed scheme has an edge over the traditional PI controller scheme counterpart.

Optimal torque control of permanent magnet synchronous machines using magnetic equivalent circuits

In recent years, permanent magnet synchronous machines (PSMs) are often designed in a mechatronic way to obtain e.g. special torque characteristics at zero currents or maximum efficiency. These designs are often characterized by a pronounced magnetic saturation and non-sinusoidal properties. This paper describes the optimal torque control of such PSMs utilizing a magnetic equivalent circuit (MEC) model. In contrast to approaches based on fundamental wave models (dq0-models), which utilize the Blondel–Park transformation and typically consider saturation and non-sinusoidal characteristics only in a heuristic way, MEC models allow to systematically account for these effects. Given the MEC model, optimal values for the coil currents are obtained from a constrained, nonlinear optimization problem, which can be efficiently solved by exploiting the special mathematical structure of the model. The results of the optimization are used in a flatness-based torque control strategy. The performance and practical feasibility of the proposed torque control concept are demonstrated by experiments on a test stand. Finally, it is shown that using this torque control in an outer angular speed control loop also proves to be beneficial.

Experimental Validation of Fuzzy-Tuned AWPI Controller-Based Chopper Driven PMDC Motor

Abstract Chopper driven Permanent magnet DC (PMDC) motors are used to drill bone and fix the screws in orthopaedic surgeries. The drive of the motor employs a traditional or modern controller that has an inner current control loop and an outer speed control loop. As an alternative to traditional proportional integral (PI) controller-based chopper drives, this paper proposes a fuzzy-tuned anti-windup PI (AWPI) controller-based chopper for the speed control of PMDC motors used in orthopaedic surgeries. The proposed scheme was simulated using Matlab/Simulink and physically realized for validation. It is ascertained from the performance analysis that the proposed fuzzy-tuned AWPI based scheme exhibits better steady-state and transient-state responses when compared with traditional PI and AWPI controllers.

A Permanent Magnet Synchronous Generator Model and Its Control Strategy

永磁同步电机(PMSG)控制是发电机组中最为关键的环节，其直接关系着发电机输出的电能质量。本文通过分析永磁同步风力发电机数学机理，分别对发电机的电压、磁链、电磁转矩以公式进行推导，根据坐标变换原理，提出采用基于外环速度、内环电流控制的双闭环矢量控制策略，该方法简便易行，对输出变量控制效果较好，最后建立发电机侧仿真模型，并分析仿真结果，验证控制策略的正确性和有效性。 Permanent magnet synchronous motor (PMSG) control is the key link in the generator set, and it di-rectly relates to the power quality of the generator output. In this paper, through analysis of perma-nent magnet synchronous wind generator mathematical mechanism, generator voltage, flux and elec- tromagnetic torque are derived respectively using formulas. According to the principle of coordinate transformation, double closed loop vector control strategy based on outer ring speed and current loop control is proposed. The method is simple and convenient, and on the output variable it has a good control effect. And finally this paper establishes the simulation model of the generator side, analyzes the simulation results and verifies the correctness and effectiveness of the control strategy.

Application of IMC Control for Rotor Side Converter of DFIG WPGS

The principle of internal model control was analyzed, which was designed as the controller for the rotor side converter of double fed induction generator based wind power generation system, the stator flux-oriented vector control structure of DFIG with internal model control was designed, with the mathematical models of the DFIG under d-q coordinated system, combined with the principle of IMC control strategy, the inner current loop and outer speed control loop was designed, the simulation shows the control characteristic.

LABVIEW BASED AUTONOMOUS AGRICULTURAL ROBOT USING FUZZY LOGIC CONTROLLER

This study proposes a LabVIEW based autonomous agricultural robot which can be used for ploughing. The control logic is designed using fuzzy logic controller to operate the robot in autonomous mode. The robot can also be controlled from a remote place using internet and its position is monitored using Global Positioning System (GPS), Data Socket protocol and Wi-Fi connection. Two DC motors are used to achieve movement control of the robot and they are controlled by the designed fuzzy logic controller. This control logic has two loops. One is outer speed control loop and the other one is inner current control loop. Based on the present position of the robot, the reference speed value is generated and based on this reference speed value the movement of an agricultural robot is controlled. Laboratory Virtual Instrument Engineering Workbench (LabVIEW) is a graphical programming environment suited for system-level design. This LabVIEW software enables complex and expensive equipment to be replaced by simpler and less expensive hardware. The primary difference between natural instrumentation and virtual instrumentation is the software component of the virtual instrument.

DSP BASED IMPLEMENTATION OF FIELD ORIENTED CONTROL OF THREE-PHASE INDUCTION MOTOR DRIVES

The objective of this paper is to presents a practical implementation of field oriented control of three-phase induction motor based on Space Vector Pulse Width Modulation technique using Digital Signal Processing (DSP) board TMS320F2812. The control algorithm for the drive application is built with Code Composer Studio version 3.1. The motor control is divided into two control loops; inner current loop and outer speed control loop using PI controller. The rotor flux quantities are estimated using computational rotor time constant, rotor angular velocity and stator current. As a feedback of field oriented control, an incremental encoder is attached at the motor shaft and a Hall effect current sensor is used to detect the sent current to the motor. The performance of the drives system is tested under different speed command and load disturbances

Development of fuzzy controlled chopper drive for permanent magnet DC motor

In this article the fuzzy logic based closed loop chopper controlled permanent magnet DC motor drive is proposed for orthopedic surgical simulators. The proposed drive consists of an inner current control loop and an outer speed control loop. The fuzzy technique is used in the speed loop and the system is simulated using Matlab/Simulink. The steady state and transient state responses of the proposed fuzzy system are compared with conventional PI controlled system. The comparative analysis infers that the fuzzy system provides better performance.

Sliding Mode Load torque Observer based effective disturbance rejection for a 3-Phase BLDC drive

controller (SMC) controller has been proposed for the outer loop speed control of the 3-Phase Brushless DC(BLDC) motor drive. The robust hysteresis controller is employed to control the inner loop current performance of the drive. The developed SMC control scheme is simulated on MATLAB/SIMULINK platform under varying load torque disturbances up to the rated torque capability and the variable speed performance of the drive is tested. A sliding mode based load torque observer has also been designed for implementation of the scheme on real time basis. The efficient load torque rejection capabilities of the developed control scheme using the sliding mode load torque observer is then compared with a Proportional Integral (PI) based controller.

Dynamic Control and Diagnostic Friction Estimation for an SPMSM-Driven Satellite Reaction Wheel

This paper presents a robust dynamic control for a DSP-based satellite reaction wheel driven by a surface-mounted permanent-magnet synchronous motor and its friction estimation from the observed disturbance. In the proposed current control scheme, a proportional-plus-integral feedback controller is augmented with a resonant-based feedback controller and a robust tracking error cancellation controller to yield an excellent sinusoidal winding current command tracking control. The controller design considering compromised performances is conducted. As to the outer loop speed control scheme, the equivalent dynamic model parameters at the nominal case are first estimated, and accordingly, a feedback controller is designed to yield the defined reference response. As the changes of the system parameters and operating conditions occur, a simple robust speed error cancellation control scheme is developed to preserve the defined response trajectory. For a larger speed command change, the ramp command with a suited ramping rate is arranged to avoid long-duration control effort saturation. Meanwhile, an observed disturbance is obtained using a nominal inverse motor drive model, and it is employed to estimate the wheel frictional condition, which can be used in diagnosing the wheel mechanical healthy condition.

Speed Control of Induction Motor Using New Sliding Mode Control Technique

Induction Motors have been used as the workhorse in the industry for a long time due to its easy build, high robustness, and generally satisfactory efficiency. However, they are significantly more difficult to control than DC motors. One of the problems which might cause unsuccessful attempts for designing a proper controller would be the time varying nature of parameters and variables which might be changed while working with the motion systems. One of the best suggested solutions to solve this problem would be the use of Sliding Mode Control (SMC). This paper presents the design of a new controller for a vector control induction motor drive that employs an outer loop speed controller using SMC. Several tests were performed to evaluate the performance of the new controller method, and two other sliding mode controller techniques. From the comparative simulation results, one can conclude that the new controller law provides high performance dynamic characteristics and is robust with regard to plant parameter variations.

Speed Control of Induction Motor Using New Sliding Mode Control Technique

Induction Motors have been used as the workhorse in the industry for a long time due to its easy build, high robustness, and generally satisfactory efficiency. However, they are significantly more difficult to control than DC motors. One of the problems which might cause unsuccessful attempts for designing a proper controller would be the time varying nature of parameters and variables which might be changed while working with the motion systems. One of the best suggested solutions to solve this problem would be the use of Sliding Mode Control (SMC). This paper presents the design of a new controller for a vector control induction motor drive that employs an outer loop speed controller using SMC. Several tests were performed to evaluate the performance of the new controller method, and two other sliding mode controller techniques. From the comparative simulation results, one can conclude that the new controller law provides high performance dynamic characteristics and is robust with regard to plant parameter variations.

DC Motor Velocity Adaptive Control through Buck-Boost AC/DC Converter with Power Factor Correction

This paper deals with the problem of velocity control of DC motors taking account the dynamics of the involved power converter. The latter is an AC/DC Buck Boost type. First, a 6th order model is developed for the global system, constituted of the motor and the converter. Based on this model, a regulator is then designed, using the backstepping technique, to achieve speed regulation and unitary power factor operation. The proposed regulator involves three loops: (i) an inner current control loop enforcing the converter input current to be in phase with the electric network voltage (unitary power factor), (ii) an outer speed control loop that regulates the machine velocity, (iii) a parameter adaptation loop that compensates the load torque uncertainty. The resulting multi-loop adaptive nonlinear regulator is formally proved to meet its objectives. This is further checked by simulation.

Dual Speed Control Scheme of Servo Drive System for a Nonlinear Friction Compensation

Servo motor drive systems with ball-screw and timing-belt are widely used in a numerical control, robot, factory automation and industrial applications. Most of the servo motor and drive system transfer the motor torque to loads via mechanical connections. However, the nonlinear friction of coupled mechanical devices reduces the performance of a servo drive. Especially, in a low speed range, tracking errors are serious due to the break-away friction and Stribeck effects. In this paper, a new dual speed controller is proposed for the compensation of nonlinear friction torque. The proposed dual speed controller has an outer speed controller and an inner friction torque compensator. The friction torque compensator adds additional torque corresponding to a nonlinear friction of mechanical devices, so the actual speed quickly tracks the reference value. Since the proposed nonlinear friction torque compensator uses the actual speed information without any motor parameters and mathematical model, the proposed compensator has a very simple structure and high stability. The proposed control scheme is verified by computer simulation and experimental results.

Design of low cost universal artificial neuron controller for chopper fed embedded DC drives

Artificial neural network (ANN) has become very popular in many control applications due to their high computation rate and ability to handle nonlinear functions. This paper proposes an artificial neuron controller for closed loop speed control of DC drive fed by DC chopper. Neuron control is used to reduce the steady state error, overshoot and settling time. The signal corresponding to the motor speed error and change in speed error are used as inputs to ANN Controller. The controller outputs the required change in duty cycle of pulse width modulated gating signal applied to DC chopper. Thus the voltage fed to the armature of the DC motor is adjusted for achieving the desired speed response. The training patterns for the neuron controller are obtained from the conventional PI controller and the effectiveness of the proposed neuron controller is studied using simulation studies. The designed controller was implemented in a low cost 8051-based embedded system and the results are documented. Two-loop control system was implemented with an inner ON/OFF current controller and an outer ANN speed controller. A conventional controller has heavy computation burden whereas a trained neural network requires less computation time. The artificial neural network has the ability to generalize and can interpolate in between the training data. This advantage of ANN makes the ANN controller universal. The ANN controller designed was tested on two different motors and found to work effectively on driving both of them.

Direct torsion control of flexible shaft in an observer-based discrete-time sliding mode

This paper presents a new speed control method for a two-mass system coupled by a flexible shaft. Two control loops are proposed; the outer angular speed control loop calculates the reference signal for the inner loop, where the torsion of the shaft is handled as a variable under control. In this paper, the observer-based discrete-time sliding-mode (ODSM) control implementation and experimental verification of direct torsion control is presented. The experimental system consists of a conventional DC servo gear motor with encoder feedback and inertia load coupled by a flexible shaft. The controller was implemented using a transputer as the computation engine.

Sliding Mode Design for Two Mass System Based on Reduced Order Model

Abstract This paper presents a new speed control method for a two mass system coupled by a flexible shaft. Two control loops are proposed, the outer angular speed control loop calculates the reference signal for the inner loop, where the torsion of the shaft is handled as a variable under control. In this paper the observer based discretetime sliding mode (ODSM) control implementation and experimental verification of direct torsion control is presented. The experimental system consists of a conventional DC servo gear motor with encoder feedback and inertia load coupled by a flexible shaft. The controller was implemented using a transputer as the computation engine.

SLIDING MODE CONTROLLER FOR PARALLEL RESONANT DUAL CONVERTERS

The classical DC drive control structure (outer speed control loop and fast inner current control loop) is applied for induction motors. This paper focuses on the inner current control (indirect current control) loop. Three Park vector based VSC (Variable Structure Control) methods (one for input rectifier two for the output inverter) are studied. In the three cases, a complex error vector, a complex sliding surface and a complex distance vector (which indicates the distance of the actual state from the sliding surface) are defined. The inverter is switched in such a way that the system trajectory gets as close to the sliding surface as possible. In spite of the fact that the error vectors have different physical meanings, similar switching strategies can be applied to all cases due to the similarity of mathematical equations. By the proposed method both the low-order harmonics and the audio noise can be reduced.

Adaptive and robust cascade schemes for thyristor driven DC-motor speed control

This paper is concerned with the development of improved cascaded speed control systems for thyristor driven DC-motors. The main features of the work can be summarized in the following four points: (1) Development of a digital dual-mode adaptive controller for the inner current control loop and of a model reference adaptive controller for the outer speed control loop, thus making the entire system adaptive. (2) Development of robust controllers both for the inner current loop and also for the outer speed loop, thus making the entire system robust. (3) Implementation of the above control strategies, adaptive and robust, in a 16-bit single board computer with floating-point coprocessor. (4) Comparison of the results of both robust and adaptive improved cascaded schemes with a commercially available controller. The obtained results showed that the model reference adaptive control concept and the robust control strategy can be applied with success for the speed control of a DC-motor.