IEE Proceedings B - Electric Power Applications

The paper concerns a battery charger that has been developed for use in a battery powered electric road vehicle. The object is to charge the 144 V traction battery directly from the 220 V supply by drawing sinusoidal current at the input, to obtain, a high efficiency and to have transformer isolation from the supply. To achieve this, the rectified 220 V supply is chopped up to 500 V by a DC to DC ... View full abstract»

The suitability of multistacked imbricated permanent-magnet rotors for use with a range of magnet materials is discussed and the optimal balance between parameters is assessed using a discrete-reluctance method and a 3-dimensional finite-element field analysis program. The effects of different permanent-magnet materials including the recently developed neodymium-iron compounds on the design of the... View full abstract»

The calculation of electromagnetic force in electromechanical devices usually requires accurate values of field quantities. This can be expensive in terms of computational effort and manpower. By using a complementary finite-element approach it is possible to significantly reduce the effort needed, and provide an error estimation on the solutions obtained. The technique is applied to practical pro... View full abstract»

A general method is described for calculating the current drawn by an inverter from its DC source. It has special relevance to pulse-width modulated inverters and allows the ripple current rating of the filter capacitor to be specified with some precision. The method is for an inverter of any number of phases and uses switching functions derived from the harmonic coefficients of the inverter wavef... View full abstract»

The paper deals with the applications of a chopper to the thyristor Scherbius which recovers slip power of a wound rotor induction machine. An analysis of the steady-state performance of this system is presented. The chopper improves in several characteristics of a conventional system. In particular, the low power factor, which is a disadvantage of the thyristor Scherbius, is significantly improve... View full abstract»

In the paper, the numerically computed variation of normalised permeance and force with apparent tooth flux density (tooth pitch flux/tooth area) is given for identically slotted doubly-salient structures. In the computations, a commercial steel B-H characteristics is used. The data cover the range of structural variables encountered in most commercial stepping motors. Flux densities reaching heav... View full abstract»

A new high-voltage suboptimal (HVSO) pulse-width modulation (PWM) switching strategy is presented which can be used at high fundamental PWM voltages to achieve a smooth, transient-free, low harmonic distortion, transition from the PWM to quasisquare-wave mode. The design philosophy underlying the development of the new HVSO strategy is aimed at reproducing the special features and desirable charac... View full abstract»

A partially decomposed variable-order model of the double-cage induction machine is presented and validated. The model exhibits improved computational efficiency in simulating full machine behaviour including stator transients. A state variable transformation is used to separate the electrical steady-state from the transient part of flux linkage response. The transient flux-linkage response is nex... View full abstract»

Thyristor controlled reactors (TCRs) are a relatively new source of harmonic distortion in power systems. The steady-state balanced (or characteristic) harmonics are easily calculated and are well known. Other noncharacteristic harmonics can, however, be generated by TCRs. A detailed representation is therefore necessary which will consider all types of imbalance, be it in the TCR or in other part... View full abstract»

The paper presents an investigation of an unusual form of solid-pole brushless alternator as a single-phase machine. Its behaviour with pulsating single-phase fields is of particular interest. The design of the prototype alternator is discussed, with special attention being given to the design considerations of this class of machines. An analysis is presented of the nonsynchronous fields in the ai... View full abstract»

The paper demonstrates the possibility of utilising resonant convertor technology in the high-frequency link inverter configuration. In this system, an amplitude modulated high-frequency sinusoidal waveform is generated by a novel type of series resonant inverter allowing electric isolation through a high-frequency transformer. A complete description of the system is presented along with its contr... View full abstract»

The paper develops a method which enables the performance of air-cored tubular induction motors to be accurately predicted. The method is versatile, being inherently capable of modelling both electrical and mechanical transients as well as nonsinusoidal current or voltage-forced excitation. The theory is verified by comparison with experimental measurements made on a test motor. View full abstract»

A control strategy for a battery powered electric vehicle employing a 3-phase induction motor drive is described. To maximise efficiency and minimise weight, a software based strategy has been developed to minimise energy loss in the battery, inverter and motor. Laboratory tests show an advantage over `traditional´ control methods. View full abstract»

An electrical stability analysis of a voltage source inverter-fed induction motor drive system is presented assuming an infinite inertia load. With a quasisquare-wave scheme this system is characterised as a linear time varying system and its stability is investigated using Liapunov's first method for stability, and also by a Routh-Hurwitz technique. The stability of each of the six individual mod... View full abstract»