# 1990 Fourth International Conference on Power Electronics and Variable-Speed Drives (Conf. Publ. No. 324)

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Displaying Results 1 - 25 of 100
• ### Aerospace induction motor actuators driven from a 20 kHz power link

Publication Year: 1990, Page(s):488 - 491
Cited by:  Papers (1)
| | PDF (176 KB)

Aerospace electromechanical actuators utilizing induction motors are under development in sizes up to 40 kW. While these actuators have immediate application to the Advanced Launch System (ALS) program, several potential applications are currently under study including the Advanced Civil Aircraft program. Several recent technology advances developed for the Space Station Freedom have allowed induc... View full abstract»

• ### Design analysis and experimental results of the thyristor pulse feeders for the ion treatment process

Publication Year: 1990, Page(s):478 - 483
| | PDF (240 KB)

From among many heat and chemical treatment methods offered on market the most effective ones proved to be the processes carried out in glow discharge conditions. By carrying out a computer simulation of the technological system inverter-chamber for ion nitriding the authors determine the most appropriate characteristics of the thyristor pulse feeders. A computer simulation of the feeder-chamber s... View full abstract»

• ### A transformer coupled single-ended parallel resonant converter

Publication Year: 1990, Page(s):132 - 135
| | PDF (192 KB)

The operation of an unusual single-ended parallel resonant converter is reviewed. This is followed by an examination of the alternative positions at which an isolation transformer may be introduced into the topology. The relative merits of each arrangement are discussed and design details and experimental results are included from a 50 W, 60 V to 12 V, 1 MHz transformer isolated converter View full abstract»

• ### Modelling and simulation of a synchronous motor supplied by a GTO voltage inverter

Publication Year: 1990, Page(s):190 - 195
Cited by:  Papers (1)  |  Patents (2)
| | PDF (180 KB)

With the development of self-commutated inverters employing GTO thyristors, new voltage waveforms which improve machine performance can be synthesized. The behavior of a synchronous motor supplied by GTO voltage inverter differs significantly from its behavior to sinusoidal input voltages in both transient and steady state regimes. For accurate prediction of the machine characteristics in time dom... View full abstract»

• ### Pulsing circuits for high power high repetition rate lasers

Publication Year: 1990, Page(s):472 - 477
Cited by:  Papers (2)
| | PDF (372 KB)

High repetition rate excimer laser systems with average output powers extending into the kW range are becoming increasingly important in a large number of scientific and industrial applications. These outputs can be achieved with optical pulse energies in excess of 0.5 J at repetition rates above 2 kHz. An experimental four stage compressor is constructed using saturable inductors constructed from... View full abstract»

• ### Thyristor assisted on-load tap changers for transformers

Publication Year: 1990, Page(s):127 - 131
Cited by:  Papers (15)
| | PDF (240 KB)

Mechanically operated on-load tap changers are widely used on power transformers to vary the output voltage by tap selection. During the process of tap changing it is essential that there is no interruption of the current flow. A method commonly used is shown where transition resistors are connected across the transformer tappings during the changeover period. The double compartment type tap chang... View full abstract»

• ### A reactorless slip recovery system

Publication Year: 1990, Page(s):306 - 311
| | PDF (244 KB)

Slip energy recovery technology for asynchronous motors is becoming increasingly important to achieve efficient utilization of energy in the context of issues facing the protection of the environment. Improvements are, therefore, continually sought in products to exploit the advances made in technologies. The authors present ABB's new generation of slip recovery drive, which the company is present... View full abstract»

• ### A new high power asymmetrical GTO

Publication Year: 1990, Page(s):424 - 428
Cited by:  Papers (3)  |  Patents (1)
| | PDF (196 KB)

The application field of the GTO thyristor is expanding and includes traction speed control equipment that is a propulsion inverter and chopper with PWM control. The ability of GTO thyristors is highly recommended being of high power and low power dissipation and fast switching. In high power GTO thyristor, one of the principal items of this ability can be operated in accordance with a small snubb... View full abstract»

• ### Operation of the permanent magnet synchronous machine without a mechanical sensor

Publication Year: 1990, Page(s):51 - 56
Cited by:  Papers (24)  |  Patents (7)
| | PDF (264 KB)

Permanent synchronous machines (PSM) score against asynchronous machines because of their simple control structure and a higher efficiency due to the small rotor losses. The necessity of sensors for angular speed and position represents a considerable restriction of robustness. Because of this, it is the aim of much research to substitute the mechanical sensors with more sophisticated models using... View full abstract»

• ### Simulation of state-events in power electronic devices

Publication Year: 1990, Page(s):184 - 189
Cited by:  Papers (1)
| | PDF (356 KB)

State-events arise in power electronic devices such as convertors. It is shown that state-events require special attention in order to avoid errors in the numerical integration procedure. The error sources are indicated and solutions provided. A simulation study indicates that proper dealing with state-events yields both faster and more accurate responses. A comparison with the electronic circuit-... View full abstract»

• ### Scalar to vector: general principles of modern induction motor control

Publication Year: 1990, Page(s):364 - 369
Cited by:  Papers (6)
| | PDF (324 KB)

Vector control principles have almost invariably been described in the past using an extremely mathematical approach. Such an approach obscures the physical concepts underlying the control technique. The authors avoid, where possible, a heavily mathematical treatment and instead give an appreciation of the basic concepts. Some fundamental ideas are reviewed, such as DC drives and conventional scal... View full abstract»

• ### The plasma position control system for ASDEX Upgrade

Publication Year: 1990, Page(s):464 - 471
| | PDF (372 KB)

One of the main tasks of ASDEX Upgrade is to develop and optimize the plasma position control system due to vertical instability of the elongated plasma ring. A system of passive and active coils serves as a means to stabilize it. The active coils are powered by the feedback amplifiers on a power level of about 30 MVA. Nonlinear circuit simulations for simplified and complex circuit models are mad... View full abstract»

Publication Year: 1990, Page(s):121 - 126
Cited by:  Papers (1)
| | PDF (364 KB)

The authors describe methods of loading three-phase induction motors, using microprocessor controlled power electronic techniques and without the need to connect a load to the machine's drive shaft. Two methods are described, one method uses microprocessor controlled power electronics to generate the two distinct frequencies and thereby replace the electrical machines of the existing equivalent lo... View full abstract»

• ### An application of medium power AC vector controlled drives

Publication Year: 1990, Page(s):301 - 305
| | PDF (172 KB)

AC drives have been traditionally applied to noncritical speed control of pumps and fans where minimal speed control or performance is required. Engineers have made use of the rugged, economical, and compact induction motor in demanding torque control applications. Since the early 1970s control strategies have been developed in an attempt to more precisely control the induction motor. Field orient... View full abstract»

• ### Improving GTO thyristor reliability by use of linear MOSFET amplifiers and controlled avalanching in gate drive circuits

Publication Year: 1990, Page(s):417 - 423
| | PDF (336 KB)

The controlled linear amplifier described has been shown to provide safe and reliable gate turn-off waveforms which may be easily adapted to the circuit conditions. The low impedance coaxial gate connections enhance the performance of the circuit and allow a greater degree of control than is possible using standard wired arrangements. For large GTOs, where the turn-off current may be in excess of ... View full abstract»

• ### Control aspects of brushless drives using switched reluctance motors

Publication Year: 1990, Page(s):237 - 242
Cited by:  Papers (5)  |  Patents (1)
| | PDF (412 KB)

Brushless variable speed drives using switched reluctance motors (SRMs) have become popular relative to other drives and represent an economical alternative to PM brushless motors in many applications. The authors discuss these control aspects of the SRM power electronic converter drive. General control and converter considerations are first briefly reviewed. A prototype 3 kW SRM is used as the fo... View full abstract»

• ### A facility for the accurate and proper determination of the transient behaviour of drive systems

Publication Year: 1990, Page(s):513 - 518
Cited by:  Patents (1)
| | PDF (308 KB)

Meticulous care is normally exercised in determining and describing the detail of transient behaviour in the power electronic converter and the electric control part of variable speed drive systems. The influence of the mechanical components that form part of the drive systems is usually not treated with the same care. The authors describe an experimental facility that has been developed to determ... View full abstract»

• ### A new approach for the field-oriented control of brushless, synchronous, permanent magnet machines

Publication Year: 1990, Page(s):46 - 50
Cited by:  Papers (1)
| | PDF (136 KB)

A new approach to the field oriented control of brushless DC machines is presented and is applied to the control of a permanent magnet synchronous motor (PMSM). The motor modelling is based on Park's d-q components. The choice of an original control algorithm, decoupling the control of the direct and quadrature currents, leads to a mathematical model easy to implement and use. Moreover, this numer... View full abstract»

• ### Design of an integrated circuit controller for brushless DC drives

Publication Year: 1990, Page(s):336 - 341
Cited by:  Papers (2)
| | PDF (348 KB)

The authors describe the design of an application-specific integrated circuit (ASIC) controller for brushless DC drives of the trapezoidal type. Cascade control is usually used for such drives, with an inner loop controlling motor current or torque and an outer loop controlling motor speed. In addition a position control loop may be needed if the drive is employed in a positioning application. The... View full abstract»

• ### A novel method for the generalised analysis of variable speed drive systems

Publication Year: 1990, Page(s):178 - 183
| | PDF (288 KB)

The authors describe a generalised linear model for variable speed drives. The powerful techniques developed in normal control theory can then be applied to this model so as to determine the modes of the system. These modes reveal whether a system is stable, close to the stability limit, or unstable. Further by transferring to the equivalent s domain, details of the frequency of the mode can be de... View full abstract»

• ### Field oriented control of an induction motor with field weakening under consideration of saturation and rotor heating

Publication Year: 1990, Page(s):286 - 291
| | PDF (304 KB)

Modern signal processors allow computation of the Park transformation for AC machines in real time. Transistor convertors can change machine voltages and currents almost immediately. Together, they perform flux and torque control as fast as it was so far only achieved by DC machines. Besides the synchronous machine with permanent magnet excitation the induction motor with squirrel cage is of speci... View full abstract»

• ### Application of estimation techniques in vector-controlled induction motor drives

Publication Year: 1990, Page(s):358 - 363
Cited by:  Papers (4)
| | PDF (324 KB)

The indirect method of vector control combines a slip calculation with a rotor position or speed measurement. The slip calculation requires a knowledge of the rotor time constant which may vary considerably over the operational range of the motor due to changes in rotor resistance with temperature. Therefore variations in motor parameters-particularly rotor resistance-should be tracked as they occ... View full abstract»

• ### Optimum design criteria for a single-step meatgrinder

Publication Year: 1990, Page(s):457 - 463
| | PDF (332 KB)

Theoretical analysis and experimental results are presented which show that a simple technique exists for optimising the design of a single-step meatgrinder feeding an uncoupled load. It is also shown that the optimum values for the two meatgrinder inductances are unaffected by the inclusion of a decompression switch. The work shows how energy can be transferred between uncoupled inductors at effi... View full abstract»

• ### Analysis of charge transfer in mixed turn-off thyristor (TOM)

Publication Year: 1990, Page(s):400 - 404
| | PDF (236 KB)

In the mixed turn-off-thyristor, (TOM for thyristor a ouverture mixte'), to remove the stored charge, the turn-off configuration of an asymmetrical GTO-thyristor is used with the assistance of an auxiliary quasi-snubber' circuit. Mechanism analysis of space-charge evolution and of charges evacuation for the gate as well as for the anode current, allows higher frequency operation and losses reduc... View full abstract»

• ### Analysis and experimental results of inverter with resonance circuits and sinusoidal output voltage

Publication Year: 1990, Page(s):218 - 223
| | PDF (220 KB)

The analysis simulation results and experimental results of the inverters with resonance circuits and sinusoidal output voltage are presented. The three-phase series-parallel inverter for high-speed drives is an example of dynamic properties of a closed-loop drive system. Simulation results were obtained using the electronic circuit analysis program package NAP-2 which was run on an IBM PC/AT comp... View full abstract»