This paper presents a new procedure for the speed changing of the twospeed compressor driven by the singlephase Permanent Split Capacitor (PSC) motor. The use of the two-speed motor for compressor is one of the effective ways for their capacity control. But the two speed compressors now in use are driven by three-phase motors. It is because a single-phase, two-speed motor has rather a small sta...

A physical realization of this winding is shown on the right above, as perhaps first proposed by Corum [1], where two counter windings of N/2 turns are each driven with current I = 2πaK(ρ = a)e−iωt/N such that the magnetic dipole moment is zero. A complication in this case is that at the N close crossings of the two windings, there is localized, oscillating charge accumulation due to the capaci...

This paper presents some analysis techniques of the voltages induced in the stator windings after supply disconnection, to detect broken rotor bars in induction motor (IM). When the motor is disconnected from the supply voltage, the broken bars cause a distortion of the magnetomotive force generated by rotor windings, and some particular harmonics induced in the stator windings increase their a...

OF DOCTORAL DISSERTATION HELSINKI UNIVERSITY OF TECHNOLOGY P.O. BOX 1000, FI-02015 TKK http://www.tkk.fi Author Andrej Burakov Name of the dissertation Modelling the unbalanced magnetic pull in eccentric-rotor electrical machines with parallel windings Manuscript submitted 08.06.2007 Manuscript revised 07.10.2007 Date of the defence 25.10.2007 Monograph Article dissertation (summary + original ...

Electromagnetic forces in power transformer windings are produced by interaction between the leakage fluxes and current passing them. Since the leakage flux distribution along the windings height is in two axial and radial directions, so the electromagnetic forces have two components, radial and axial. There is a risk that a large electromagnetic force due to the short circuit or inrush current...

The paper presents the electromagnetic (EM) wave propagation in cylindrical optical fibers with helical windings under slowand fast-wave considerations. Field components are deduced for both the cases, and also, the dispersion relations are obtained by applying the boundary conditions, as modified by the presence of conducting helical windings. Two special cases are considered corresponding to ...

This short note is a description of the analysis of single phase induction motors. It is intended to be read along with a description of the analysis of polyphase motors1.This will be called the ’reference document’. The style of analysis used here is described in more detail in that note and many of the elements of this analysis appear only in that other note. The single phase machine contempl...

In many years teaching of Electric Machinery, Electrical Engineering Theory, and Power System Analysis, I found that students have difficulty learning how to calculate transformer parameters. It is even more difficult for them to understand the reason of reducing capacity of short circuit of three windings transformer which has different capacities in each winding. However, the calculation of t...

In the paper, a new low-order parametric force model for an electrical machine with eccentric rotor is developed and verified. The model is designed for an electrical machine equipped with both the parallel stator windings and rotor cage, and, therefore, accounts for the equalising currents in the stator and rotor windings separately and also for their influence on each other. Furthermore, the ...