Influence of shape and material of rotor bars on performance characteristics of single-phase self-excited induction generators

Abstract

Purpose The purpose of the paper is to present an analysis of an influence of shape and material of rotor bars on the process of self-excitation and performance characteristics of single-phase, self-excited induction generator (SP-SEIG). Design/methodology/approach The presented analysis is based on the results of transient simulations of SP-SEIG performed with the use of field-circuit model of the machine. Four various shapes of the rotor bars and two different conductor materials were investigated. The results for the base model with rounded trapezoidal rotor slots were validated by measurements. Findings An improvement of the performance characteristics – the extension of the stable operating range of the generator – was obtained for rectangular copper rotor bars. The improvement is the result of strong skin effect in the squirrel rotor cage. Application of round rotor slots results in shorter time of voltage build-up during the self-excitation of the generator caused by less apparent deep bar effect in round bars. Originality/value The originality of the paper is the application of the copper rotor cage in the single-phase, self-excited induction generator. Its use is beneficial, as it allows for extension of the range of stable operating range. The results may be used for designing new constructions of the single-phase, self-excited induction generators, as well as the constructions based on general purpose single-phase induction motors.

Optimum design of slot and magnet structure of permanent magnet synchronous generator with teaching‐learning‐studying‐based optimization

“…In the literature, the effect of the rotor slot structure in four different models (rounded trapezoidal slots, round slots, rectangular slots, and trapezoidal slots) in a single‐phase asynchronous generator has been investigated. The skin effect in the round rotor structure has been determined to be less than the rectangular structure 7 . The split ratio, magnet ratio, magnet thickness, stator and rotor slot opening ratio parameters of the flux reversal permanent magnet machine have been examined in different stator/rotor slot numbers.…”

“…The skin effect in the round rotor structure has been determined to be less than the rectangular structure. 7 The split ratio, magnet ratio, magnet thickness, stator and rotor slot opening ratio parameters of the flux reversal permanent magnet machine have been examined in different stator/rotor slot numbers. In the study, it was determined that the output torque increased when the slot opening increased.…”

An Analytical Model of Induction Motors for Rotor Slot Parametric Design Performance Evaluation

“…Apart from studying normal rotor bar shapes, the effect of broken rotor bar and different stator slot opening settings were tested using FEM technique to evaluate the induction motor performance [6], [11]. Investigation on the rotor bar shapes was also carried out in [12], but they focused on generator rather than motor applications.…”

Comparative analysis of single-phase self-excited induction generators of various rotor cages

“…For production of low-power single-phase electrical energy, self-excited induction generators (SP-SEIGs) driven by a micro-hydro or micro-wind turbine may be applied. Usually, for single-phase power generation as an auxiliary energy source at household, single phase of two separate stator windings' induction machines of power up to 3 kW will be sufficient operating as an autonomous single-phase selfexcited induction generator [1][2][3][4][5][6]. When larger electrical power is needed, a three-phase stator winding self-excited induction generator with single-phase output should be employed for feeding single-phase loads [7][8][9].…”

“…for bars and rings) of single-phase self-excited induction generators instead of aluminium which is commonly used in general-purpose single-phase capacitor induction motors. Taking into account previously conducted study by the authors in [4], only three shapes of rotor bars, i.e. rounded trapezoidal, rectangular and round, have been considered in this paper for two different conductive materials.…”