By Topic

Electric Power Applications, IEE Proceedings B

Issue 4 • Date Jul 1990

Filter Results

Displaying Results 1 - 12 of 12
  • Computer-aided selection of variable-reluctance stepping motors

    Page(s): 223 - 230
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (668 KB)  

    The authors describe an interactive computer procedure for the selection of motor and power circuit parameters in variable-reluctance stepping motor systems. A system of prioritising aspects of the target performance provides an extremely flexible approach and ensures that the procedure can be used to specify either a complete system or just one component of the system. The versatility of the procedure is illustrated by its application to such tasks as improving efficiency through adjustments to the freewheeling circuit and matching the dimensions of a motor using standard laminations to a particular dynamic torque requirement View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Dynamic performance analysis of reluctance motors using damping and synchronising torques

    Page(s): 231 - 238
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (552 KB)  

    The authors analyse the dynamic performance of polyphase reluctance motors using damping and synchronising torques. A numerical algorithm has been applied to obtain these torque components in the time domain using detailed nonlinear models of reluctance motors. The effects of all electrical motor parameters have been examined and the optimum values of parameters, which give maximum damping of hunting oscillations, have been obtained. It has also been demonstrated that these optimum parameters substantially improve the dynamic performance of reluctance motors. The presented results form a guide to the production of reluctance motors with well-damped oscillations and improved dynamic performance View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Tubular linear induction motor for use as a servo actuator

    Page(s): 273 - 280
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (540 KB)  

    The authors describe the theory of a tubular linear induction motor (TLIM). The properties of this motor, with its high speed and low moving mass, make it attractive to use as a servo motor for linear mechanical movements. A laboratory built TLIM is analysed using the complex phasor method, giving a starting point for the design of a control strategy in the transient mode, while from this analysis, the steady state behaviour is evaluated and compared with measurements View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Harmonic analysis of space vector modulated PWM waveforms

    Page(s): 197 - 204
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (528 KB)  

    While most traditional PWM inverters use the asymmetrical regularly sampled triangulation technique to generate waveforms, a recently reported space vector PWM method is rapidly gaining favour in the industrial drives arena as an alternative technique. The paper presents an analysis of the space vector PWM waveform to obtain its spectrum. The analysis is based on a novel decomposition technique, illustrated by considering the harmonics of a regularly sampled asymmetrical sinusoidal PWM waveform, which is in fact a partial solution to the space vector harmonics. The calculated harmonics show close agreement with measured harmonics from an experimental microprocessor-controlled inverter operating with the same waveform parameters View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Dynamic flux controlled AC drive

    Page(s): 259 - 264
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (468 KB)  

    A dynamic flux controlled drive for a cage induction motor uses a technique called `phase-decoupling' to improve significantly the transient response of a scalar-controlled drive while retaining all the inherent advantages of the method. The strategy requires a versatile PWM modulator, but it is applicable to a wide variety of applications, achieving a transient performance surpassing most other transducerless flux-controlled systems, in particular those using slip reconstruction methods. The controller is simple and practical to implement and requires no external transducers. The authors discuss the theoretical basis for the method and compare detailed computer simulations with equivalent experimental investigations View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Novel technique for the optimal online control of a PWM voltage/source inverter

    Page(s): 248 - 252
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (368 KB)  

    A new technique for the online identification of a communication pattern allowing harmonic loss minimisation in a PWM voltage/source inverter is presented. A control strategy based on it is developed and simulation results are included to demonstrate the feasibility of the proposed method View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Series connected PWM GTO current/source convertor with symmetrical phase angle control

    Page(s): 205 - 212
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (616 KB)  

    A series connected pulse width modulated current-source convertor (CSC) with symmetrical phase angle control, employing gate turnoff thyristors, is investigated for high voltage applications, where the sinusoidally modulated pulse width is kept sufficiently large to suppress the harmonics by employing a constant modulation index. It should be appreciated that in this system the power flow can be easily controlled, with a high power factor and nearly sinusoidal supply currents. Furthermore, to demonstrate the usefulness of the system, its transient behaviour with a digital PI controller is examined experimentally by looking at its step responses. They are verified by an approximate prediction method without a complete simulation. In addition, the active and reactive powers are examined to investigate their distribution in the system View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Compound, series, axial flux induction machines: single phase analogy

    Page(s): 265 - 272
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (560 KB)  

    The characteristics of the single phase analogy of a pair of axial flux, polyphase induction motors having their respective stator windings and also their magnetic circuits in series, with provision for `out of balance' flux, arising due to differences in the two rotor speeds, to pass through a saturating magnetic shunt are investigated. Theoretical and experimental results show that when such a pair of machines, fed from a single, variable frequency supply, is used to drive two wheels of one electronic vehicle, torque/speed characteristics that more closely match those of the ideal mechanical differential are obtained than when two independent induction machines are fed either in series or in parallel from a single supply View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Implicit rotor position sensing using search coils for a self-commutating permanent magnet drive system

    Page(s): 253 - 258
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (472 KB)  

    A novel form of rotor position sensing is described that makes use of a simple search coil system in a permanent magnetic machine. It can be used for almost any field configuration and permanent magnet material provided that there is a reluctance variation between the direct and quadrature axes. Practical results are presented for a particular rotor configuration. A closed-loop speed control system gives precise speed control and operation at high efficiency. This enables a complete drive system to be implemented, involving torque angle control for optimal performance View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Direct phase modelling of synchronous generators

    Page(s): 239 - 247
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (620 KB)  

    Accurate nonlinear modelling of the synchronous generator in the dqo reference frame has been well documented. To extend the analysis to a wider range of loading conditions, the generator is modelled in the abc reference frame. The unsaturated static and dynamic saturated inductances of the machine in this reference frame are obtained using conventional dqo-abc transformation techniques. A new set of equations in the phase reference frame has been derived employing the dynamic inductance concept. The model utilises new dynamic saturated inductances that remove the error present in the conventional direct phase nonlinear model using only static saturated inductances. The mathematical model has been used to simulate the performance of a laminated salient-pole alternator with direct thyristor excitation. The predicted results show good agreement with test results View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Oscillating synchronous linear motor in electromechanical resonance

    Page(s): 281 - 292
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (992 KB)  

    The symmetric double acting oscillating synchronous linear motor with longitudinal functional air gaps is very well suited to the system synthesis of the electronically controlled drive for working resonant machines used in industrial vibrational techniques. It can be designed for a stroke of up to a few centimetres and a working frequency ranging from about 6 to 70 Hz. What is important in practice is the motor operation in electromechanical resonance with a compensated synchronising (AC) motor circuit and a compensated mechanical load. Then, the operational motor characteristics, derived under the assumption of harmonic oscillations, are functions of real variables. An analysis of these characteristics yields the features of a steady-state motor with harmonic oscillations. Attention is paid to the motor self regulation and the control of the velocity or path amplitude of its oscillations. The theoretical outcome, applicable also for the case of a not fully harmonic motor power supply from a static convertor, is in good agreement with the experimental results obtained from researching motor prototypes of 1 and 5.7 kW View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Analysis of power electronic circuits with feedback control: a general approach

    Page(s): 213 - 222
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (744 KB)  

    An algorithm that is suitable for the development of general purpose simulation software for power electronic circuits is presented. The circuits can be arbitrarily configured and can incorporate feedback controls. The method of analysis uses an efficient nodal approach that allows the device switchings to be easily monitored. The basic nodal formulation, including the method used to monitor device switching, is discussed. The method used to efficiently formulate the nodal equations for the power and control circuits is described. Several examples that illustrate the main features of the method are presented View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.