DOCSLIB.ORG

Linear Servomotor Probe Drive System with Real-Time Self-Adaptive Position Control for the Alcator C-Mod Tokamak

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Linear Servomotor Probe Drive System with Real-Time Self-Adaptive Position Control for the Alcator C-Mod Tokamak PSFC/JA-16-60 Linear servomotor probe drive system with real-time self-adaptive position control for the Alcator C-Mod tokamak D. Brunner, A.Q. Kuang, B. LaBombard, and W. Burke October 2016 Plasma Science and Fusion Center Massachusetts Institute of Technology Cambridge MA 02139 USA This work was supported by DoE Contract DE-FC02-99ER54512 on Alcator C-Mod, a DoE Office of Science user facility. Reproduction, translation, publication, use and disposal, in whole or in part, by or for the United States government is permitted. Linear servomotor probe drive system with real-time self-adaptive position control for the Alcator C-Mod tokamak D. Brunner, A.Q. Kuang, B. LaBombard, and W. Burke [email protected] Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts, 02139, USA A new servomotor drive system has been developed for the horizontal reciprocating probe on the Alcator C-Mod tokamak. Real-time measurements of plasma temperature and density—through use of a mirror Langmuir probe bias system—combined with a commercial linear servomotor and controller enables self-adaptive position control. Probe surface temperature and its rate of change are computed in real time and used to control probe insertion depth. It is found that a universal trigger threshold can be defined in terms of these two parameters; if the probe is triggered to retract when crossing the trigger threshold, it will reach the same ultimate surface temperature, independent of velocity, acceleration, or scrape-off layer heat flux scale length. In addition to controlling the probe motion, the controller is used to monitor and control all aspects of the integrated probe drive system. 1 Introduction Plasma probes, i.e., measurement instruments that make direct contact with the plasma, have been one of the primary tools to study boundary plasma physics in experimental fusion reactors. Probes enable excellent temporal resolution (up to ~1 MHz with present technology1) and spatial location (sub- millimeter) of many quantities of interest: ion and electron temperatures, plasma density, plasma potential, flow velocities, and magnetic field. Reciprocating systems allow probes to measure and survive plasma in conditions too intense for stationary probes. Fast reciprocation of the probe into and out of the plasma limits the probe exposure to high heat flux. The reciprocations are typically fast enough to take advantage of ‘inertial cooling’, i.e., a situation in which only a thin surface layer is heated. In this case, active cooling of the probe will not enable deeper scanning. It is desirable to scan the probe as deep as possible. However, the exponentially increasing heat flux profile a tokamak scrape-off layer presents a considerable challenge, requiring accurate control of the probe trajectory – in particular the insertion depth. There are two effects that limit scan depth: (1) Melting the probe should be avoided. Melting can cause the probe tip to deform (making the collection area and thus the inferred density uncertain), shorting of the electrode (rendering it useless), and termination of the tokamak plasma (through a large impurity injection). (2) Even before melting, as the surface temperature is raised the probe can undergo thermionic electron emission. The electrons emitted from the probe reduce the sheath potential (rendering plasma potential measurements uncertain) and increase the net current collected during ion saturation measurement (making plasma density measurements uncertain). Fortunately, enhanced electron emission occurs at a surface temperature that is significantly below melting temperature. Thus, the onset of electron emission can often be used as a marker to identify the maximum useful scan depth without irreversible damage to the probe. Reciprocating probe systems have been implemented and used on many plasma physics experiments. A comprehensive list would include nearly every magnetic fusion experiment. For a partial list see Ref. 2. Most systems have relied on a pneumatic or hydraulic drive to reciprocate the probe into and out of the plasma. Pneumatic/hydraulic drives have the advantage of being a simple system with few components. 1 They are relatively easy to implement and can readily achieve velocities (~1 m/s) as well as accelerations (>100 m/s2) that enable effective operation. The major disadvantage of pneumatic/hydraulic systems is the control of their ultimate plunge depth. This is typically done by trial and error. The plasma boundary shape from a previous plasma pulse is taken into account and the position of the pneumatic cylinder that drives the probe is adjusted (typically with a slow stepper motor) such that it scans deep enough to measure interesting plasma physics but not so deep as to destroy the probe. In order to minimizing the dwell time at the probe’s end-of-stroke (during maximum heat flux), the C-Mod pneumatic systems additionally engage a mechanical return spring that provides a large turn-around acceleration (~600 m/s2). Some other systems rely solely on toggling air or hydraulic pressure to the opposite side of the cylinder to change probe direction, resulting in a much lower turn-around acceleration and shallower scan depth into the plasma. Neither of these pneumatic systems have sufficient time response for precise, real-time control of probe position in narrow scrape-off layers. Electromagnetic systems, however, can have sufficient performance for real-time control. Electronic circuits can respond fast enough (<1 ms) to turn the probe around in time. Electromagnetic control of probe movement can been implemented in three ways: (1) Using standard servomotors (either linear3 or rotary4) with a series of permanent magnets to provide a background field; (2) Using the magnetic field of the experiment to provide the background field5–10; (3) Using pulsed electromagnets to induce currents in a ‘drive hoop’11. In first two cases a current is passed through a coil or series of coils and the Lorentz force between the current in the coil(s) and the background magnetic field provides the acceleration. In the third case the image currents in the ‘drive hoop’ act against the pulsed electromagnets. Both an electromagnetic, the so-called ‘pecker-probe’, and a hydraulic reciprocating probe with real- time control were operated on Tore Supra10,12. The output of a real-time calculation of the magnetic equilibrium was used to control the ultimate depth of each probe scan. This is not a viable technique for use on Alcator C-Mod; the magnetic equilibrium reconstruction of the plasma boundary and the probe- measured boundary plasma can drift over the course of a plasma shot (it is presumed that this is due to currents redistributing in the copper toroidal field coils as they heat up). That is, for an equilibrium with a constant boundary plasma position at the outer plasma-wall gap, the probe-measured plasma temperature and density profile can drift away from the probe. The profiles can drift a few millimeters— a few heat flux decay lengths. That size of variation in the actual plasma position relative the calculated equilibrium does not provide for a useful feedback technique. Since probe insertion depth is practically limited by surface temperature, a better approach is to control the probe depth based on real-time measurements of probe surface temperature. Experiments indicate that this should be feasible: an IR camera was used to measure the heat flux on a reciprocating probe on ASDEX-U13 and surface thermocouples14 could be integrated into a probe. A less direct, but perhaps simpler solution, would be to use real-time measurements of the plasma quantities at the probe tip combined with a thermal model of the probe to calculate surface temperature. The Mirror Langmuir Probe1 (MLP) bias system provides real-time measurements of plasma temperature and flux. An MLP is an analog computer that quickly switches (~3 MHz) through three bias states of a Langmuir probe I-V (current-voltage) trace. The system optimizes each bias voltage through use of circuitry that mirrors the Langmuir probe response in the plasma. A by-product of this is real-time 2 outputs proportional to the three fit parameters to the I-V: ion saturation current (Isat, proportional to the plasma flux), electron temperature (Te), and floating potential (Vf, related to the plasma potential through sheath theory). To complement the MLP analog computer we have developed an analog computer that ‘solves’ a thermal model of the Langmuir probe body, outputting the surface temperature evolution of the probe head in real time. It uses real-time MLP Te and Isat measurements to compute the incident plasma heat flux, based on a simple sheath heat flux model. The scanning probe system must be capable of diagnosing a wide variety of scrape-off layer plasma profiles. As discussed below, this makes it impractical to use surface temperature alone as a parameter to trigger a turn-around response. Fortunately, the scrape-off layer profiles are close to exponential. In this case, a fairly reliable estimate of the surface temperature at a future time can be made based on the current temperature and its time derivative. Using these two parameters, we’ve found a robust, universal control algorithm that is able to trigger the probe’s turn-around such that its surface temperature stays below a specified peak temperature. This paper is organized as follows. Section 2 explores the optimization of probe acceleration and velocity for maximizing the depth of probe scan into the plasma while ensuring controllability. A universal control algorithm is developed in Section 2. Section 3 describes the mechanical design and implementation of the linear servomotor system. Section 4 covers the control (software and electrical) interface, including the surface temperature analog computer. Section 5 describes operational results of the linear servomotor drive system on Alcator C-Mod. 2 Thermal performance The thermal performance is the crucial concern when considering designing a reciprocating probe system with feedback control.
Load more

Recommended publications
  • Control of DC Servomotor
    Control of DC Servomotor Report submitted in partial fulfilment of the requirement to the degree of B.SC In Electrical and Electronic Engineering Under the supervision of Dr. Abdarahman Ali Karrar By Mohammed Sami Hassan Elhakim To Department of Electrical and Electronic Engineering University of Khartoum July 2008 Dedication I would like to take this opportunity to write these humble words that are unworthy of expressing my deepest gratitude for all those who made this possible. First of all I would like to thank god for my general existence and everything else around and within me. Second I would like to thank my beloved parents(Sami & Sawsan), my brothers (Tarig & Hassan), and my sister (Latifa), thank you so much for your support, guidance and care, you were always there to make me feel better and encourage me. I would like also to thanks all my friends inside and out Khartoum university, thank you for your patients tolerance and understanding, for your endless love that has stretched so far, for easing my pain and pulling me through. A special thanks to my partner Muzaab Hashiem without his help and advice i won’t be able to do what i did, thank you for being an ideal partner, friend and bother. Last but not the least i would like to thank my supervisor Dr. Karar and all those who helped me throughout this project, thank you for filling my mind with this rich knowledge. Mohammed Sami Hassan Elhakim. I Acknowledgement The first word goes to God the Almighty for bringing me to this world and guiding me as i reached this stage in my life and for making me live and see this work.
    [Show full text]
  • Stepper Motor Or Servo Motor: Which Should It Be?
    Stepper Motor or Servo Motor: Which Should It Be? Engineer the Exceptional ENGINEER THE EXCEPTIONAL ENGINEER THE EXCEPTIONAL Stepper Motor or Servo Motor: Which Should It Be? Engineer the Exceptional ENGINEER THE EXCEPTIONAL Each technology has its niche, and since the selection of either stepper or servo ENGINEER THE EXCEPTIONAL technology affects the likelihood of success, it is important that the machine designer consider the technical advantages and disadvantages of both to select the best motor-drive system for an application. Machine designers should not limit utilization of steppers or servos This article presents an overview of stepper according to a fixed mindset or comfort level, but should learn where and servo capabilities to serve as selection each technology works best for controlling a specific mechanism and criteria between the two technologies. process to be performed. A thorough understanding of these technologies will help you achieve optimum Today’s digital stepper motor drives provide enhanced drive features, mechatronic designs to bring out the full option flexibility and communication protocols using advanced capabilities of your machine. integrated circuits and simplified programming techniques. The same is true of servo motor systems, while higher torque density, improved electronics, advanced algorithms and higher feedback resolution have resulted in higher system bandwidth capabilities as well as lower initial and overall operating costs for many applications. STEPPER MOTOR SYSTEM OVERVIEW Stepper motors have several major advantages over servo systems. They typically cost less, have common NEMA mountings, offer lower-torque options, require less-costly cabling, and their open-loop motion control simplifies machine integration and operation.
    [Show full text]
  • Stepping Motors Fundamentals
    AN907 Stepping Motors Fundamentals Author: Reston Condit TYPES OF STEPPING MOTORS Microchip Technology Inc. There are three basic types of stepping motors: Dr. Douglas W. Jones permanent magnet, variable reluctance and hybrid. University of Iowa This application note covers all three types. Permanent magnet motors have a magnetized rotor, while variable reluctance motors have toothed soft-iron rotors. Hybrid INTRODUCTION stepping motors combine aspects of both permanent Stepping motors fill a unique niche in the motor control magnet and variable reluctance technology. world. These motors are commonly used in measure- The stator, or stationary part of the stepping motor ment and control applications. Sample applications holds multiple windings. The arrangement of these include ink jet printers, CNC machines and volumetric windings is the primary factor that distinguishes pumps. Several features common to all stepper motors different types of stepping motors from an electrical make them ideally suited for these types of point of view. From the electrical and control system applications. These features are as follows: perspective, variable reluctance motors are distant 1. Brushless – Stepper motors are brushless. The from the other types. Both permanent magnet and commutator and brushes of conventional hybrid motors may be wound using either unipolar motors are some of the most failure-prone windings, bipolar windings or bifilar windings. Each of components, and they create electrical arcs that these is described in the sections below. are undesirable or dangerous in some environments. Variable Reluctance Motors 2. Load Independent – Stepper motors will turn at Variable Reluctance Motors (also called variable a set speed regardless of load as long as the switched reluctance motors) have three to five load does not exceed the torque rating for the windings connected to a common terminal.
    [Show full text]
  • Stepper Motor
    STEPPER MOTOR Stepper motors are used in a wide variety of applications, including computer peripherals like printers, scanners, CD drives, camera lenses, etc. In this first article, in a series of articles on stepper motors, we will introduce the reader to the theory behind the working and control of a stepper motor. Stepper Motor Basics A Stepper Motor just like any other motor, converts electrical energy into mechanical energy. A stepper motor consists of the following parts: Stator The stationary part of the motor. In a stepper motor, the stator is a set of electromagnets. Rotor The non-stationary part of the motor. In a stepper motor, the rotor is a permanent magnet. The arrangement of the electromagnets and the permanent magnets in a simple stepper motor is shown in the following diagram. Stepper Motor Construction Stepper Motor Operation Stepper Motor Operation When each of the electromagnet pairs is energized successively, the permanent magnet is attracted to the electromagnet, and aligns with it. This results in rotation of the permanent magnet. This is illustrated in “Stepper Motor Operation” diagram. The stepper motor gets its name from the fact that the rotor rotates in discrete step increments. The simple stepper motor has a step angle of 90 degrees. More complex stepper motors can have step angles as low as 3.6 degrees. These stepper motors have more no. of poles in the rotor. A complex stepper motor is shown in below diagram. The dark grey areas on the rotor are South poles and light grey areas on the rotor are North poles.
    [Show full text]
  • Stepper Motors
    Stepper Motors By Brian Tomiuk, Jack Good, Matthew Edwards, Isaac Snellgrove November 14th, 2018 1 What is a Stepper Motor? ● A motor whose movement is divided into discrete “steps” ○ “Turn 10 steps clockwise” ● Holds its position without additional control ○ No sensor or feedback loop 2 Parts of a Stepper Motor Stator - Stays Static Rotor - Rotates the motor shaft https://phidgets.files.wordpress.com/2014/06/stepper_back_web.jpg 3 Different Types of Torque Holding torque - How much load can the motor hold in place when the coils are energized Detent torque - The torque the motor produces when the windings are not energized, sometimes call residual torque 4 Advantages of Stepper Motors ● Has high holding torque (maintains its position) ● Moves in discrete amounts ● Inexpensive ● Brushless (can last longer than brushed motors) 5 Disadvantages of Stepper Motors ● Uses the same amount of power regardless of load ○ Lower power efficiency ● Torque decreases rapidly as speed increases ● No internal feedback ○ Cannot tell when a step was missed ○ Must step slowly to ensure accuracy ● Low torque to inertia ○ Cannot accelerate loads very rapidly 6 How Stepper Motors Work 7 How a Stepper Motor Works Unpowered Electromagnets Bar with magnetic ends A basic stepper motor consists of a series of electromagnets surrounding a magnetically charged bar 8 How a Stepper Motor Works S Powering a pair of the electromagnets causes the middle bar to align with the electromagnets S 9 How a Stepper Motor Works Changing which electromagnets are powered and unpowered
    [Show full text]
  • DC Servo Motor Modeling
    MODELING DC SERVOMOTORS CONTROL SYSTEMS TECH NOTE © Dr. Russ Meier, MSOE INTRODUCTION A DC motor is an actuator that converts electrical energy to mechanical rotation using the principles of electromagnetism. The circuit symbol for a DC motor is shown in Figure 1. + Va M - Figure 1: Circuit symbol for a DC servomotor The learning objectives of this technical note are: 1. Draw the equivalent DC servomotor circuit theory model. 2. State the equations of motion used to derive the electromechanical transfer function in the time domain and the s-domain. 3. Draw the DC servomotor signal block diagram. 4. Derive the DC servomotor electromechanical transfer function. CIRCUIT THEORY MODEL The circuit shown in Figure 2 models the DC servomotor. Note that an armature control current is created when the armature control voltage, Va, energizes the motor. The current flow through a series-connected Ra La + + Tm Va Vb R θ m - - Figure 2: DC servomotor circuit theory model armature resistance, an armature inductance, and the rotational component (the rotor) of the motor. The rotor shaft is typically drawn to the right with the torque (Tm) and angular displacement (θm) variables shown. The motor transfer function is the ratio of angular displacement to armature voltage. Figure 3: The DC servomotor transfer function EQUATIONS OF MOTION Three equations of motion are fundamental to the derivation of the transfer function. Relationships between torque and current, voltage and angular displacement, and torque and system inertias are used. Torque is proportional to the armature current. The constant of proportionality is called the torque constant and is given the symbol Kt.
    [Show full text]
  • Direct Drive Dc Torque Servo Motors
    DIRECT DRIVE DC TORQUE SERVO MOTORS QT- Series Rare Earth Magnet Motors DIRECT DRIVE DC SERVO MOTORS The Direct Drive DC Torque motor is a servo actuator which can be directly attached to the load it drives. It has a permanent magnet (PM) field and a wound armature which act together to convert electrical power to torque. This torque can then be utilized in positioning or speed control systems. In general, torque motors are deigned for three different types of operation: » High stall torque (“stand-still” operation) for positioning systems » High torque at low speeds for speed control systems » Optimum torque at high speed for positioning, rate, or tensioning systems SUPERIOR QUALITY With the widest range of standard and custom motion solutions, we collaborate with you to deploy rugged, battle-worthy systems engineered and built to meet your singular requirements. Kollmorgen provides direct drive servo motor solutions for the following applications: » Weapons stations and gun turrets » Missile guidance and precision-guided munitions » Radar pedestals and tracking stations » Unmanned ground, aerial and undersea vehicles » Ground vehicles and sea systems » Aircraft and spacecraft systems » Camera gimbals » IR countermeasure platforms » Laser weapon platforms QT- Series D irect Drive DC Servo Motors Advantages of Direct Drive DC Torque Motors Direct drive torque motors are particularly suited for servo system applications where it is desirable to minimize size, weight, power and response time, and to maximize rate and position accuracies. Frameless motors range from 28.7mm (1.13in) OD weighing 1.4 ounces (.0875 lbs) to a 4067 N-m (3000 lb-ft) unit with a 1067mm (42in) OD and a 660.4mm (26in) open bore ID.
    [Show full text]
  • Permanent Magnet Servomotor and Induction Motor Considerations
    Permanent Magnet Servomotor and Induction Motor Considerations Kollmorgen B-104 PM Brushless Servomotor at 0.4 HP Kollmorgen M-828 PM Brushless Rotor Kollmorgen B-802 PM Brushless Servomotor at 15 HP Kollmorgen B-808 PM Brushless Rotor Permanent Magnet Servomotor and Induction Motor Considerations 1 Lee Stephens, Senior Motion Control Engineer Permanent Magnet Servomotor and Induction Motor Considerations Motion long considered a mainstay of induction motors, encroachment in the area of 50 HP and greater have been seen recently for some applications by permanent magnet (PM) servomotors. These applications usually have dynamic considerations that require position-time closed loop and high accelerations. When accelerating large loads, permanent magnet servomotors can work with very high load to inertia ratios and still maintain performance requirements. Having a lower inertia typically will allow for less permanent magnet motor can result in a greater torque energy wasted within the motor. Torque (τ), is the density than an equivalent induction system. If size product of inertia (j) and rotary acceleration (α). If you matters, then perhaps a system should use one require inertia matching, ½ of your energy is wasted technology over another. Speaking of size, the inertia accelerating the motor alone. If the inertia ratio from ratio can be an important figure of merit should motor to load is large, then control schemes must be dynamic needs arise. If you are going to have high dynamic enough to prevent the larger load from driving accelerations and decelerations, the size of the rotor the motor as opposed to the motor controlling the load. will significantly increase the inertia and decrease the Tradeoffs and knowing what can be negotiated.
    [Show full text]
  • Piezoelectric Inertia Motors—A Critical Review of History, Concepts, Design, Applications, and Perspectives
    Review Piezoelectric Inertia Motors—A Critical Review of History, Concepts, Design, Applications, and Perspectives Matthias Hunstig Grube 14, 33098 Paderborn, Germany; [email protected] Academic Editor: Delbert Tesar Received: 26 November 2016; Accepted: 18 January 2017; Published: 6 February 2017 Abstract: Piezoelectric inertia motors—also known as stick-slip motors or (smooth) impact drives—use the inertia of a body to drive it in small steps by means of an uninterrupted friction contact. In addition to the typical advantages of piezoelectric motors, they are especially suited for miniaturisation due to their simple structure and inherent fine-positioning capability. Originally developed for positioning in microscopy in the 1980s, they have nowadays also found application in mass-produced consumer goods. Recent research results are likely to enable more applications of piezoelectric inertia motors in the future. This contribution gives a critical overview of their historical development, functional principles, and related terminology. The most relevant aspects regarding their design—i.e., friction contact, solid state actuator, and electrical excitation—are discussed, including aspects of control and simulation. The article closes with an outlook on possible future developments and research perspectives. Keywords: inertia motor; stick-slip motor; smooth impact drive; piezeoelectric motor; review 1. Introduction Piezoelectric actuators have long been used in diverse applications, especially because of their short response time and high resolution. The major drawback of these solid state actuators in positioning applications is their small stroke: actuators made of state-of-the-art lead zirconate titanate (PZT) ceramics only reach strains up to 2 . A typical piezoelectric actuator with 10 mm length thus reaches a maximum stroke of only 20 µm.h Bending actuator designs [1] and other mechanisms [2] can increase the stroke at the expense of stiffness and actuation force ([3]; [4] (pp.
    [Show full text]
  • Simple Torque Control Method for Hybrid Stepper Motors Implemented in FPGA
    electronics Article Simple Torque Control Method for Hybrid Stepper Motors Implemented in FPGA Stefano Ricci * and Valentino Meacci Information Engineering Department (DINFO), University of Florence, 50139 Florence, Italy; valentino.meacci@unifi.it * Correspondence: stefano.ricci@unifi.it; Tel.: +39-0552758585 Received: 12 September 2018; Accepted: 4 October 2018; Published: 7 October 2018 Abstract: Stepper motors are employed in a wide range of consumer and industrial applications. Their use is simple: a digital device generates pulse-bursts and a direction bit towards a power driver that produces the 2-phase currents feeding the motor windings. Despite its simplicity, this open-loop approach fails if the torque load exceeds the motor capacity, so the motor and driver should be oversized at the expense of efficiency and cost. Field-Oriented closed-loop Control (FOC) solves the problem, and the recent availability of low cost electronics devices like Digital Signal Processors, Field Programmable Gate Arrays (FPGA), or even Microcontrollers with dedicated peripherals, fostered the investigation and implementation of several variants of the FOC method. In this paper, a simple and economic FOC torque control method for hybrid stepper motors is presented. The load angle is corrected accordingly to the actual shaft position through pulse-bursts and direction commands issued towards a commercial stepper driver, which manages the 2-phase winding currents. Thanks to the FPGA implementation, the control loop updates the electrical position every 50 µs only, thus allowing a load angle accuracy of −1/100 rad for a rotor velocity up to 750 rev/min, as shown in the reported experiments. Keywords: stepper motor; torque control; closed-loop control; Field Programmable Gate Array (FPGA) 1.
    [Show full text]
  • Control System Lab Lab Manual
    CONTROL SYSTEM LAB (EC-616-F) CONTROL SYSTEM LAB (EC-616-F) LAB MANUAL VI SEMESTER Department of Electronics & Computer Engg Dronacharya College of Engineering Khentawas, Gurgaon – 123506 CONTROL SYSTEM LAB (EC-616-F) CONTROL SYSTEM LIST OF EXPERIMENTS PAGE S. NO NAME OF THE EXPERIMENT NO. 1. TO STUDY A.C SERVO MOTOR AND PLOT ITS 1 TORQUE SPEED CHARACTERISTICS. TO STUDY D.C SERVO MOTOR AND PLOT ITS 5 2. TORQUE SPEED CHARACTERISTICS. TO STUDY THE MAGNETIC AMPLIFIER AND PLOT ITS 8 LOAD CURRENT V/S CONTROL CURRENT 3. CHARACTERISTIC FOR (A)SERIES CONNECTED MODE (B)PARALLEL CONNECTED MODE. TO PLOT THE LOAD CURRENT V/S CONTROL 11 4. CURRENT CHARACTERISTICS FOR SELF EXCITED MODE OF THE MAGNETIC AMPLIFIER. 5. TO STUDY LEAD LAG COMPENSATOR AND DRAW 14 MAGNITUDE AND PHASE PLOTS. TO STUDY A STEPPER MOTOR & EXECUTE 17 MICROPROCESSOR OR COMPUTER BASED CONTROL 6. OF THE SAME BY CHANGING NUMBER OF STEPS, DIRECTION OF ROTATION & SPEED. TO IMPEMENT A PID CONTROLLER FOR LEVEL 20 7. CONTROL OF A PILOT PLANT TO STUDY THE BASIC OPEN LOOP AND CLOSED LOOP 23 8. CONTROL SYSTEM. TO STUDY WATER LEVEL CONTROL USING 26 9. INDUSTRIAL PLC. TO STUDY THE MATLAB PACKAGE FOR SIMULATION 29 10. OF CONTROL SYSTEM DESIGN. CONTROL SYSTEM LAB (EC-616-F) EXPERIMENT NO: 1 AIM: - To study AC servo motor and plot its torque speed Characteristics. APPARATUS REQUIRED: - AC Servo Motor Setup, Digital Multimeter and Connecting Leads. THEORY: - AC servomotor has best use for low power control applications. Its important parameters are speed – torque characteristics. An AC servomotor is basically a two phase induction motor which consist of two stator winding oriented 90* electrically apart.
    [Show full text]
  • Servomotor Parameters and Their Proper Conversions for Servo Drive Utilization and Comparison
    Servomotor Parameters and their Proper Conversions for Servo Drive Utilization and Comparison Servomotor Parameters and their Proper Conversions for Servo Drive Utilization and Comparison 1 Hurley Gill, Senior Application / Systems Engineer Servomotor Parameters and their Proper Conversions for Servo Drive Utilization and Comparison Utilization of servomotor parameters in their correct units of measure as defined by the drive manufacturer is imperative for achieving desired mechanism performance. But without proper understanding of motor and drive parameter details relative to their defined terms, units, nomenclature and the calculated conversions between them, incorrect units are likely to be applied which complicate both machine design development and the manufacturing process. This white paper demonstrates exactly how and 6-step (i.e. trapezoidal commutation). While machine designers can overcome challenges most servomotor parameters are presented in one around servomotor parameters and apply them of three ways, they are often mixed between the correctly for any motor or drive to meet specific two different electronic commutation methods. requirements. A customary standard set of servo (Refer to Motor Parameters Conversion Table on units is thoroughly explained together with their page 6.) typical nomenclature and the applicable conversions between them. Typical terminologies used to describe While the motor parameter data entered into the servomotors are: Brushless DC Motor (BDCM or servo drive must be in the units that the designer BLDCM) Servo, Brushless DC/AC Synchronous specifically intended, there are often differences Servomotor, AC Permanent Magnet (PM) Servo between this data and their defined corresponding and other similar naming conventions. Most of units of measure presented on a motor datasheet.
    [Show full text]