Detection of Stator Winding Short Circuit Faults Through Magnetic Fields In Induction Motors

In applications in the industrial world, the use of induction motors has been widely used in operation because induction motors have many advantages, although they have many advantages, induction motors themselves also have disadvantages, namely having high starting currents. In many cases the damage to the induction motor, the damage to the stator due to a short circuit, is a frequent failure, this damage can cause considerable losses because the motor can stop operation So this research will discuss about the detection of short circuit faults in the stator winding through leaky flux using a flux sensor that is placed outside the motor and placed radially and using the Fast Fourier Transform (FFT) method. Damage to the short circuit is done by reconstructing the stator winding of the induction motor. There are two variations of short circuit damage, namely short circuit winding 1 to winding 3 and short circuit winding 2 to winding 10 on an induction motor. The short circuit data is then processed using the Fast Fourier Transform method which produces data in the form of voltage to frequency. The results of the percentage of success of short circuit fault detection seen from the loaders have an average percentage of 50%, at no load conditions can detect short circuit faults by 100%. In conditions of short circuit interruption 1-3 has a success percentage of 30% and short circuit fault 2-10 by 70%. The existence of this system is expected to be able to anticipate any damage that can cause considerable and fatal losses.

An Approach to the Use of an External Magnetic Field As a Diagnostic Sign of an Asynchronous Motor Malfunction

The article deals with the issues related to the possibility of diagnosing the technical condition of an asyn-chronous electric motor by an external magnetic field. The justification of the problems associated with the di-agnosis of electric motors is given. The difficulties that arise when measuring the external magnetic field of electric motors, as well as the devices with which it is possible to carry out measurements, are described. The re-lationship between the EMF of the sensor and the external magnetic field is shown. The results of processing the EMF waveforms induced by an external magnetic field in an inductive sensor for various electric motors are presented. The processing was carried out by the fast Fourier transform method. The external magnetic field contains the first harmonic and various harmonics that are multiples of the combination of the stator teeth, or the sum of the stator and rotor teeth that fall on one pair of poles. The ratio of the amplitudes of the first and tooth harmonics is affected by the measurement location and the orientation of the sensor. Diagrams showing the ratio of the main and tooth harmonics at different points of the motor body are constructed. The depend-ences of the harmonic amplitudes on the magnitude of the magnetizing current of the stator are given. Changes in the amplitudes and spectrum of harmonics in the presence and absence of an inter-turn short circuit in the stator winding are shown. Diagrams of the circular external magnetic field for the main and higher harmonics are constructed. The study shows the possibility of using an external magnetic field to detect inter-turn short circuits of the stator winding.

Housing Profile Design for Improved Apex Seal Lubrication Using a Finite Length Roller Elastohydrodynamic Lubrication Model

Finite-length roller contacts are found in apex seal-housing interfaces in rotary engines, as well as in many other mechanical systems, such as those at the interfaces of meshing gear teeth, cam followers, and roller bearings. Rollers are usually designed with crowns and modified ends to mitigate the negative effects of misalignment, thermal deformation, and edge-induced non-uniform displacement. A crowned-roller elastohydrodynamic lubrication model is enriched and employed to investigate seven housing surface profiles, including a sinusoidal recess, sinusoidal ends, the combination design of a sinusoidal recess and sinusoidal ends, multiple sinusoidal recesses, a concave shape, and a concave shape with sinusoidal ends or round corners, aiming to improve the tribological performance of the interface via increasing the minimum film thickness but reducing the average and maximum film thicknesses, and lowering friction coefficient. The modified discrete convolution and fast Fourier transform method with duplicated padding is utilized to deal with the potential free-end-surface effect. The simulation results suggest that the combinations of a concave shape and sinusoidal ends, or round corners, are the best designs because they can help distribute the lubricant most uniformly without causing a negative edge effect.

Real Time Pitch Detection For Vocal Tuning Using FFT Algoritma And Spectrogram

The song is a means of entertainment most often heard by humans where in the song consists of music and vocals. Good quality music and vocal singers will make a song more pleasant to hear. To make the song sound tunable and in accordance with the rhythm can be done by adjusting the vocals according to the tone of the song. From this we know that measuring sound frequencies needs to be done to determine whether a frequency or period is loud, it can also be used as a tool in vocal training, one of them for vocal tuning applications to find the harmonious sound of the sound. Moreover, it can be used as a learning need in Sound Frequency Processing. Where one of the parts to create a vocal tuning application can be through the Real-time spectrogram program. This RTS uses Pyaudio as sound recording, uses the Python 3.6 programming language and uses the Fast Fourier Transform method which will help when making real-time spectrogram and pitch detection programs. The test results obtained 75% accuracy in real-time pitch detection programs.

Mengenali pengaruh emosional pada suara manusia menggunakan metode Fast Fourier Transform (FFT)

Emotion is a feeling that is felt by someone and can be addressed to other people or something and can arise as a reaction due to certain events. Some previous studies have stated that some statistical parameters have a high correlation between speech and emotional states that can indirectly influence the state of sound identified. In this study a simple experiment was carried out by taking nine samples with three different emotional characters namely sad, happy, and angry taken from three respondents who were randomly selected with the aim of identifying differences in emotions generated through sound data using the Fast Fourier Transform method ( FFT).

Sistem Pengolah Musik Sebagai Kontrol Gerak Robot Humanoid

Pada Kontes Robot Seni Tari Indonesia (KRSTI), mengharuskan peserta untuk dapat membuat robot yang dapat menari secara otomatis dengan diiringi alunan musik. Tujuan penelitian ini adalah membuat robot humanoid yang dapat menari ketika musik pengiring diputar dan berhenti ketika musik berhenti. Penelitian ini menggunakan IC MSGEQ7 sebagai pengolah musik karena IC ini dapat membaca nilai frekuensi musik secara detail sebanyak tujuh frekuensi yaitu frekuensi 63Hz; 16Hz; 400Hz, 1kHz; 2,5kHz; 6,25kHz; dan 16kHz. Ketujuh frekuensi tersebut dijadikan acuan sebagai isyarat robot untuk bergerak atau berhenti. Penentuan frekuensi sebagai isyarat gerak didapat melalui sampling musik Tari Remo menggunakan perangkat lunak Matlab dengan metode FFT (Fast Fourier Transform). Isyarat gerak tersebut dikirimkan ke sistem robot melalui Modul Bluetooth HC-05. Jika sistem robot mendapat isyarat untuk bergerak maka robot akan menggerakkan servo penggerak menjadi gerakan yang serasi. Hasil yang didapat dari pengujian adalah dapat diketahui frekuensi yang sering muncul pada musik tari remo yaitu pada frekuensi 0-4000Hz. Setelah frekuensi diketahui, implementasi pada robot memperoleh hasil robot dapat menari ketika musik diputar dan robot dapat berhenti ketika musik dihentikan.At the Indonesian Dance Robot Contest (KRSTI), it requires participants to be able to make robots that can dance automatically accompanied by music. The purpose of this study is to create a humanoid robot that can dance when the accompaniment music is playing and stop when the music stops. This study uses IC MSGEQ7 as a music processor because this IC can read music frequency values in detail as many as seven frequencies namely 63Hz frequency; 16Hz; 400Hz, 1kHz; 2.5kHz; 6.25kHz; and 16kHz. The seven frequencies are used as a reference as a robot signal to move or stop. The determination of the frequency as a gesture is obtained through the sampling of Remo Dance music using Matlab software with the FFT (Fast Fourier Transform) method. These motion signals are sent to the robot system via the Bluetooth Module HC-05. If the robot system gets a signal to move, the robot will move the servo drive into a matching movement. The results obtained from testing are the frequency that often appears in Remo dance music, namely the frequency 0-4000Hz. After the frequency is known, the implementation of the robot obtains the results that the robot can dance when the music is playing and the robot can stop when the music is stopped.

Effect of the finite size of generated rough surfaces on the percolation threshold

Percolation threshold is a very important parameter to estimate the sealing performance. Thus, it is crucial to determine the correct value of the percolation threshold for contact sealing surfaces. In this paper, we applied a numerical generation method, in which the autocorrelation length can be easily controlled, to obtain different Gaussian isotropic rough surfaces. Then, the contact status between a rigid flat half-space and numerically generated rough surfaces were calculated using the conjugate gradient-fast Fourier transform method. Based on the contact status, the percolation threshold was obtained using a search method. The calculated results established that the percolation threshold of [Formula: see text] is determined for Gaussian isotropic contacting rough surfaces. To obtain an exact value of the percolation threshold, the finite size of the generated rough surfaces should be six times greater than the autocorrelation length, and the autocorrelation length should not be smaller than 20 times the sampling interval.