A robust speed control algorithm for a DC servomotor based on zeroing and model matching techniques is devised. The algorithm is implemented by a fast digital signal processor(DSP). Robust speed reguration is experimentally achieved.

Plenty of previous motor speed control system approaches are based on the assumption that motor speed to be controlled is available for measurement. In order to get more accuracy, the assumption is not suitable, while the time lag problem the processing time of the control program and the motor speed detecting may cause the system unstable. This paper proposed to use a predictive state observer to reconstruct actual motor speed, calculate the estimated value of the instaneous speed of the next sampling instant before the actual next sampling instant is reached. Comparing their results it has shown that this new approach is better then the conventional ones.

An identity state observer for the smooth-rotor permanent-magnet synchronous motor is derived which reconstructs the electrical and mechanical states of the motor from current and voltage measurements. The observer operates in the rotor frame and estimates direct and quadrature stator currents, rotor velocity, and rotor position. Since the rotor position is estimated, the rotor reference frame is approximated using the latest rotor position estimate. The motor dynamics and the transformation into the estimated rotor frame are nonlinear and thus the observer and observer error dynamics are nonlinear. Therefore, small signal stability is analyzed from a linearized model. Simulations including realis-tic measurement disturbances are used to investigate the global stability and accuracy of the observer.

A new control method of the AC synchro-nous servo-system (Brushless DC servo-system) is discussed. The new system is based on the armature voltage prediction model. Without a resolver-digital-conver-ter nor a tachometer-generator, the resolver provides following three signals to the system immediately, they are the current command, the induced voltage, and the rotor speed. The new method realizes a simple hardware configuration. Experimental results show a good performance of the system.

The relatively recent development of the theory of vector control has enabled ac machines to be transformed, performance wise, into equivalent separately excited dc machines while retaining the many advantages that ac machines have over dc. The ac machines used include the induction and permanent magnet synchronous motors. A precise knowledge of the machine parameters is needed in order to implement indirect vector control on induction motor drive systems where the position of the rotor flux is not measured. If the machine parameters change relative to the preset values in the vector controller, then the decoupling of the torque and flux channels, which is the object of vector control, is lost. Low frequency torque and speed oscillations can result with a consequent degradation in the drive performance. The PMSM drive system is also parameter sensitive although not depending on the same parameters as the induction motor drive. It is well known that machine parameters change with temperature, saturation and on the frequency of operation. An assessment of the overall performance of an ac motor drive must therefore include a study of its parameter sensitivity. In this paper, a detailed steady state study of parameter sensitivity for both the induction and permanent magnet machines is done. Comparisons are also made based on the results of this investigation.

The stationary and dynamic behaviour of multi-motor drives in processing machines with continuous moving webs will be investigated. The influence of the web forces is neglected up to now normally during the optimization of the control. Poor dynamic behaviour is the result of this simplification. To improve the dynamic behaviour of the controlled system, new concepts with adaptive state space controllers and observers are considered. As a first step the decoupling method for the multi-motor drive-system with decentralized observers will be investigated. Then the optimal constant output feedback will be applied and at last an adaptive state space control for axial winders is described. The results, obtained from these new approaches will be compared to the results of conventional approaches. Furthermore practical experiments show the advantages of the new concepts.

A variable speed drive system is studied which consists of the inverter-fed permanent magnet field synchronous motor without a rotor position sensor and a rotating speed sensor. A method is explained, which determines the rotor position angles at a standstill or at rotating conditions and the speed at several conditions by measuring the instantaneous values of phase voltages and currents. The experimental results obtained by a prototype drive system without a rotor position and a speed sensor are compared with the those obtained by an ordinary DC brushless servo system with a rotor position sensor and a tachogenerator.

A Position Control Algorithm with interesting features has been used in the design of an electro-mechanical actuator for a particular application where volume and weight limits are extremely tight. Position feedback, non-linear derived rate feedback, a saturable full-time main integrator, an intermittent fast integrator, compensation for mechanical system compliance, and derived acceleration feedback are used in an extension and modification of classical control concepts. The calculating and decision making power of a microcomputer contained in the actuator has been used to significantly improve upon well known control methods for this special case.

The purpose of the paper is to propose a new high-performance optimal position servo of an induction motor fully controlled by a micro-computer, which was designed and realized through a waterfall type top-down design in a newly developed CAD environment. Field-orientation control was used to design a new voltage-controlled optimal regulator for position control. Globally stable observers were designed and utilized to overcome the restricted availability of sensed variables: winding voltages & currents and shaft speed & angle. The digital scheme was experimentally tested and verified. Also shown is the effect of quantization errors and sampling period in A/D's & D/A's on the response and accuracy of the control system.

Two algorithms for the digital control of position of a three phase SCR controlled DC motor are compared. The digital control is novel in that the sampling period is variable and depends on the firing angles of the SCR's. While the algorithms are not new, their use with a variable sampling period in this application is. Performance is assessed through both simulation on a digital computer of the controlled motor and an implementation on a microprocessor based bench model. Both algorithms give equivalent performance in terms of step response to position commands.

This paper proposes a new linear adaptive drive system of brushless DC servo motor. The proposed method can rapidly reject the state error caused by both parameter variations and force disturbance. The structure of this adaptive control method is based on the dual passive adaptive control loop. The drive system using this dual loop can realize the strictly robust control of brushless DC servo motor. Numerical and experimental examples show that the proposed method is effective for suppression of parameter variations and force disturbance.

This paper presents a new attractive approach for a vector control system of AC machine by state space method. First state equations of an induction machine suitable for the current control are derived. It becomes clear that the induction machine can be described as three input-three output controlled object. New vector control theory is formed and developed based on an optimal regulator technique. The proposed control system have excellent characteristics for changes in the desired signal and disturbance signal, and in spite of parameter variations of the controlled object. Several simulation results are presented.

The direct method of Lyapunov is used to study the stability of a Lienard-type nonlinear system. The system is given in a form of n second-order ordinary differential equations. To establish the procedure for constructing Lyapunov function, a similar system is derived first, by multiplying both sides of the system equation by a transformation matrix. Then, a stability criterion for the Lienard-type nonlinear system, which introduces a new type Lyapunov function, is presented. The function obtained is a generalized Lyapunov function. The construction procedure given in this paper is applied to an example system represented by so-called Lienard's equation and the superiority of the proposed function is illustrated by numerical examples.

Recent research has indicated that the permanent magnet motor drives which include the permanent magnet synchronous motor (PMSM) and the brushless DC motor (BDCM) could become serious competitors to the induction motor for servo applications. The PMSM has a sinusoidal back emf and requires sinusoidal stator currents to produce constant torque while the BDCM has a trapezoidal back emf and requires rectangular stator currents to produce constant torque. The PMSM is very similar to the wound rotor synchronous machine except that the PMSM that is used for servo applications tend not to have any damper windings and excitation is provided by a permanent magnet instead of a field winding. Hence the d,q model of the PMSM can be derived from the well known model of the synchronous machine with the equations of the damper windings and field current dynamics removed. Because of the nonsinusoidal variation of the mutual inductances between the stator and rotor in the BDCM, it is also shown in this paper that no particular advantage exists in transforming the abc equations of the BCDM to the d,q frame. Hence the solution of the original abc equations is proposed for the BDCM.

The switched reluctance motor (SRM) drive has recently received attention mainly because of its simple motor construction and unidirectional converter requirement. The principle of operation of the motor drive demands that the motor and converter be treated as one unit. Little has been done to develop a complete analysis of this motor-converter combination 1'2. This paper presents an approach to the steady state analysis of the SRM drive including the effects of stator winding resistance, input filter dynamics and snubber circuits which are often neglected. The analysis yields phase current waveforms providing guidelines to the optimal design of the converter and motor. A novel single-switch-per phase converter developed by one of the authors is used. The approach can be used for any other motor-converter combination.

In view of the fact that the cleanliness of production environment greatly affects the reliability and yield rate of semi-conductor circuits, the authors have developed a contactless actuator intended for use in clean rooms and vacuums. The devised actuator is a stepping motor with a function of magnetic suspension. Thus the motor has the propelling and positioning ability of an ordinary stepping motor, and at the same time that of contactless guiding and support by magnetic suspension. Owing to the characteristic toothed pole structure of the stepping motor, its structure and driving conditions were optimized to minimize the possible fluctuation of the attractive force acting between the stator and rotor. From experiments, gap fluctuation amplitude has been confirmed to be no greater than 1% of preset gap length. In this paper, the structure and design of the motor are introduced. Also, the structure and basic performance of three types of linear and rotary contactless positioning mechanisms using the devised motor are introduced. The use of the motor as super-clean DD motor for machines and robots is expected.

The Power Electronics Computer Aided Simulation and Design (PECADS) is a new CAE package to be used in every Simulation and Design task for Static Power Converters MP controlled 1.71,49 Pesthe present work presents their Simulation and Modelling developped Tools. The Real Structure Simulation is presented here for all Matrix and No Matrix Converter types as a new concept. The System Modeling and Identification is also presented as a new way to design Digital Controllers MP based. The present work follows the new Digital Simulation and Redesign concept 3° and is a complementary continuation of e", e.

This paper presents an algorithm for the real time simula-tion of a full-wave controlled rectifier bridge in a multiprocessor based environment. It is shown that every switch can be mod-eled as an inductor which is controlled by a local controller. As the topology of the circuit changes due to the closing and open-ing of the switches, it is shown that only one set of equations is needed to characterize the circuit.

This paper presents a new technique in microprocessor drive and control circuits for power electronic equipments. This technique uses the PWM programmed method and one DMA controller to generate the drive pulses to switches. With this solution we get high performance in aspects as angle resolution and real time response. It has been developed a simple modular hardware and a control software useful in a lot of power applications. After tests in prototypes, results and conclusions are presented.

A high-speed, microprocessor-based pulse width modulator for three-phase inverters, realizing the so called incremental pulse width modulation algorithm, is presented. Computational simplicity of the algorithm results in fast, on-line operating capability and low memory requirements of the modulator. Fast operation of the modulator ensures high effectiveness of low-order harmonic reduction of the inverter output voltage. Principles of the incremental pulse width modulation are explained and experimental results are provided along with the description of the modulator.

A single chip INTEL 8748 based Pulse Width Modulation system has been developed. Six PWM signals for three phase application are generated on PORT 1 by outputting DATAWORDs after a delay determined by DELAY-WORDs. Two different sets of DATAWORDs are used for forward and reverse motions. The PWM signals have been used to run two ac synchronous motors to control a tracking photovoltaic system. The motion of the tracker is decided by Input signals on BUS PORT and PORT 2 (UPPER). Bit 6 and 7 of PORT 1 and lower nibble of PORT 2 are used as gate signals for tri-state buffers to control two or more motors from one set of PWM signals.

A single-chip microcomputer-based con-troller for a pulsewidth modulated 1.7 KVA inverter of an airconditioner is presented. The PWM pattern generation and the system control of the airconditioner are achieved by software of the 8-bit single-chip micro-computer. The single-chip microcomputer has the disadvantages of low processing speed and small memory capacity which can be overcome by the magnetic flux control method. The PWM pattern is generated every 90 psec. The memory capacity of the PWM look-up table is less than 2 kbytes. The simple and reliable control is realized by the software-based implementation.

Accuraty output torque is necessary to get, when the induction motor drives is fed by an inverter (like P.W.M.). In this paper we presented a new algorithm to control the DC/AC inverter, that is called BOXES algorithm. Boxes Hardware to control an induction motor is also presented. Field-oriented Theory is used in this work to facilitate the motor simulation and, as known, to can used the motor model as state observor. Finally, (Recursive Least Sequare) identification method, and digital freq-uency analysis is used to design the induction motor control algorithm.

A new PWM inverter suitable for use of power MOSFETs is described. The output waveforms in the proposed PWM inverter are investigated both theoretically and experimentally. A modulating signal for the three-phase PWM inverter is obtained by superposing a rectangular wave on the specific trapezoidal wave. This modified signal lends itself to a simple three-phase construction. The output PWM waveform for the new modulating signal does not include the fifth harmonic component and an amplitude of fundamental component is increased by about 20 percent more than that of a conventional PWM inverter. As each inverter arm does not operate during two-third period, the heat generated in the devices are reduced. That is, the size of the inverter system is minimized because of the reduction in the heat dissipating equipment.

In this paper, we realize an advanced inverter system consists of a reference oscillator, a discrete type arithmetic operation circuit and a switching circuit. The arithmetic operation circuit determines the switching timing (PWM pattern) automatically on the basis of the time sequence data of the difference between the current and the reference signal. This circuit is synthesized by using bang-bang servo technique and it can be implemented by using several BBD elements and operational amplifiers. This circuit is valid for fairly wide change of the magnitude and frequency of the reference input and some variation of the load impedance.

New chopper circuits for decoupled operation of the dc series motor are presented. These new choppers are capable of controlling field current completely separately, while offering capability of bidirectional armature energy flow. To develop the chopper circuit, with minimum number of switching elements, the complete family of possible conduction circuits are systematically investigated. Then one or two quadrant chopper circuits which offer the desired operations are synthesized from the resulting conduction circuits. Finally, the developed chopper circuits are completely analyzed. The details of operation of the chopper circuits are also fully described.

This paper considers the thyristor chopper circuits constituted of a power circuit (source, main thyristor, load and freewheeling diode), a basic commutation circuit and a voltage reversion circuit (to make the commutation capacitor voltage polarity adequate to commutate the main thyristor current). Different possibilities of connection of basic commutation circuits into the chopper power circuit and possible techniques for reversal of commutation capacitor voltage polarity are presented. As a result, derivation of large number of topologies is systematised.

Superconducting Magnetic Energy Storage(SMES) is a potential energy storage having fast response and high efficiency. For the simultaneous control of real and reactive power in SMES, asymmetrically controlled 6 pulse converter has been introduced instead of conventional 12 pulse converter. Unique features of asymmetrical control including commutation process, maximum control angles, generated harmonics have been discussed. Effectiveness of the proposed method has been proved experimentally using a 25 KJ SMES.

A delta-connected cycloconverter promises high performance and moderate cost for ac motor drives. The circulating current of the cycloconverter is used for controlling the input reactive power. There exists stong interaction between the load current control and the circulating current control. This paper presents the decoupling control method for substantial isolation of both control loops.

A computer-aided design of a high-performance driving circuit for floating power Mosfet switch is presented. Very fast switching and large duty cycle ratios are achieved. Design methodology and optimization procedures using computer circuit simulator SPICE 2 are given.

This speed control system uses an AC/AC direct converter as driver, featuring that its output frequency margin goes from 0 to 127 Hz. Four quadrant speed control is entirely done by a microcomputer and calculation of the time functions of each power circuit bidirectional static switches (PCBSS) is done in real time, obtaining a high flexibility, high resolution, very trustworthy and drive circuit least components system.

The gage accuracy of strip coil in the tandem cold mills has much possibility of improvement with the advanced control techniques. In conventional dc motor mill drives, however, the limit on speed control response makes it difficult to achieve the higher accuracy in the gage control. The circulating current cycloconverter-fed squirrel cage induction motor drive system with entirely digital control scheme has been employed at Mizushima No.2 tandem cold mil for the purpose of improvement in the gage accuracy.

The study recorded in this paper is related to the steady state operation of self controlled permanent magnet synchronous motor, fed by voltage source inverter in a closed loop mode. The inverter is a pulse width modulated one. Motor load angle is controlled through a precise feedback circuit with the aid of a high resolution optical encoder. A complete study of the different operating points performance is carried out. Comparison between three values of P.W.M ratios is achieved to give on idea of different operating points.

A microprocessor control scheme for a switched reluctance motor(SRM) drive is discussed. A SRM is inherently a variable speed machine since it requires a converter even for constant speed running. Starting with a conceptual development, a particular hardware scheme is discussed for controller implementation. Hardware-software tradeoffs incorporated in the design are discussed. Some results of an actual system are evaluated. It is shown that a microprocessor controller has many advantages over conventional controllers. The controller design uses rotor position and speed feedbacks. Self-starting is incorporated into the design. Use of off-the-shelf components makes the controller simple, reliable, and economical.

Advanced digital control and computer-aided control system design techniques are playing key roles in the complex drive system design and control implementation. The paper describes a high performance microcomputer-based control and digital simulation of an inverter-fed interior permanent magnet (IPM) synchronous machine which uses Neodymium-Iron-Boron magnet. The fully operational four-quadrant drive system includes constant-torque region with zero speed operation and high speed field-weakening constant-power region. The control uses vector or field-oriented technique in constant-torque region with the direct axis aligned to the stator flux, whereas the constant-power region control is based on torque angle orientation of the impressed square-wave voltage. All the key feedback signals for the control are estimated with precision. The drive system is basically designed with an outer torque control loop for electric vehicle application, but speed and position control loops can be added for other industrial applications. The distributed microcomputer-based control system is based on Intel-8096 microcontroller and Texas Instruments TMS32010 type digital signal processor. The complete drive system has been simulated using the VAX-based simulation language SIMNON* to verify the feasibility of the control laws and to study the performances of the drive system. The simulation results are found to have excellent correlation with the laboratory breadboard tests.