Innovative Construction of the AFPM-Type Electric Machine and the Method for Estimation of Its Performance Parameters on the Basis of the Induction Voltage Shape

The article presents an innovative construction of the Axial Flux Permanent Magnet (AFPM) machine designed for generator performance, which provides the shape of induced voltage that enables estimation of the speed and rotational angle of the machine rotor. Design solutions were proposed, the aim of which is to limit energy losses as a result of the occurrence of eddy currents. The method of direct estimation of the value of the rotational speed and rotational angle of the machine rotor was proposed and investigated on the basis of the measurements of induced voltages and machine phase currents. The advantage of the machine is the utilization of simple and easy-to-use computational procedures. The acquired results were compared with the results obtained for estimation performed by using the Unscented Kalman Filter (UKF).

EFFICIENCY OF FOAM WASTEWATER DISPOSAL

Получены динамические характеристики производительности пеногенератора от времени в сточной воде при различных концентрациях некаля, являющегося поверхностно-активным веществом, и переменной глубине погружения сопла. The dynamic characteristics of the foam generator performance as a function of time in the waste water at different concentrations of non-crystal, which is a surfactant, and variable nozzle immersion depth are obtained.

The Harmonics Effect of Variable Speed Drives on Generator Performance

Large motors often burden synchronous generators as power plants in factories. This motor is commonly using to regulate rotation using Variable Speed Drive (VSD). From the load side, VSD, as a regulator of motor rotation, can reduce power loss. On the generator side as a power plant, this load with VSD affects the waveform of the generator. The experiments on a small capacity generator (6 kVA) with a VSD as regulating the motor rotation with a load of about 1.1 kW shows effectiveness power transfer is about 40.7% with VSD, and without VSD, efficiency is approximately 39.6%. The motor losses by installing VSD interpreted as transferring losses to the generator with savings is about 1 %. The experiments also showed that generator performance decreases when loaded with VSD at around 6%, and a generator temperature increases at 20 0C higher than without VSD.

Effect of magnetic slot wedge on the performance of bulb tubular turbine generator

Purpose Owing to the salient pole structure and stator slots of hydro-generator, the air gap magnetic field in the generator is unevenly distributed. High-frequency harmonic components contained in the inhomogeneous air gap magnetic field will have a negative impact on the generator performance. The purpose of this paper, therefore, is to improve the distribution of air gap magnetic field by using appropriate magnetic slot wedge, thereby improving the generator performance. Design/methodology/approach Taking a 24 MW, 10.5 kV bulb tubular turbine generator as an example, the 2 D electromagnetic field model of the generator is established by finite element method. The correctness of the model is verified by comparing the finite element calculation data with the experimental data. The influences of the permeability and thickness of the magnetic slot wedge on the generator performance are studied. Findings It is found that the intensity and harmonic content of the air gap magnetic field will change with the permeability of slot wedge and then the performance parameters of the generator will also change nonlinearly. The relationship between the eddy current loss, torque ripple, output voltage and other parameters of the generator and the permeability of slot wedge is confirmed. In addition, the variation of losses and torque with wedge thickness is also obtained. Originality/value The influence mechanism of magnetic slot wedge on the performance of hydro-generator is revealed. The presented results give guidelines to selecting suitable magnetic slot wedge to improve generator performance.