Ibrahim Senol

Detection of bearing defects in three-phase induction motors using Park’s transform and radial basis function neural networks

This paper investigates the application of induction motor stator current signature analysis (MCSA) using Park’s transform for the detection of rolling element bearing damages in three-phase induction motor. The paper first discusses bearing faults and Park’s transform, and then gives a brief overview of the radial basis function (RBF) neural networks algorithm. Finally, system information and the experimental results are presented. Data acquisition and Park’s transform algorithm are achieved by using LabVIEW and the neural network algorithm is achieved by using MATLAB programming language. Experimental results show that it is possible to detect bearing damage in induction motors using an ANN algorithm.

Detection of outer raceway bearing defects in small induction motors using stator current analysis

We investigate the application of induction motor stator current spectral analysis (MCSA) for detection of rolling element bearing damage from the outer raceway. In this work, MCSA and vibration analysis are applied to induction motor to detect outer raceway defects in faulty bearings. Data acquisition, recording, and fast fourier transform (FFT) algorithms are done by using the Lab VIEW programming language. Experimental results verify the relationship between vibration analysis and MCSA, and identify the presence of outer raceway bearing defects in induction machines. This work also indicates that detecting fault frequencies by motor currents is more difficult than detecting them by vibration analysis. The use of intensive resolution FFT is recommended in MCSA for detecting faults easily. Reinstalling a faulty bearing can alter the characteristic frequencies and it is difficult to compare results from different bearings or even from the same bearing in different installations.

Position control of induction motor a new‐bounded fuzzy sliding mode controller

Purpose – The aims of the paper are to improve the dynamic response of an induction motor based position servo system and to remove the chattering problem in the sliding mode control theory by using fuzzy logic principles. The obtained results are also compared with conventional sliding mode controller to show its performance.Design/methodology/approach – The main method used for the research is to form a thin boundary layer neighboring the switching surface by using fuzzy logic. The sliding mode control law is inherently discontinuous naturally. Therefore, there are some difficulties such as so many switches occurring between the control bounds, which cannot be carried out by real controllers. Therefore, fuzzy logic is used in the thin boundary layer to determine the control signal current. Thus, the chattering is eliminated.Findings – The results show that the designed controller has superior performance. But, there are also some difficulties. It is difficult to obtain fuzzy rules. The rules can be obta...

Dynamic performance and analysis of direct torque control method based on DSP for PMSM drives

This paper presents theoretical analysis and experimental verification of the direct torque control (DTC) for permanent magnet synchronous motor (PMSM) drive. PMSM drive is characterized by the direct torque control based on space vector pulse-width modulation (SVPWM) method which is controlled by digital signal processor (DSP). Since the constant switching frequency is produced by SVM technique, the space vector PWM control method enables the drive to produce voltage vector of any direction and magnitude thus, torque ripple is eliminated compared with classical hysteresis DTC. The proposed DTC method includes simplified reference flux vector calculator and torque estimator introducing space vector pulse-width modulation (SVPWM) method. Experimental results obtained by a motor & generator setup are shown to verify the operating principle and performance. As a result, the experimental setup exhibits validity of the analysis and to demonstrates good dynamic response.

A novel approach to sensorless control of induction motors

In this paper, sensorless control of induction motor is studied by reducing the adverse effect caused by the variation of the rotor time constant, which is the most effective parameter. For this purpose, a new robust observer for the parameter variation, is designed with the combination of sliding mode approach and Luenberger observer. Then, the observer is used in the rotor flux oriented vector control of induction motor. The control hardware is realized by using a motion control card on a computer. The current and the voltage values of the motor are transferred to the control algorithm software by means of the analog-to-digital converter on the motion control card. The actual speed of the motor is measured through the encoder and it is compared with its estimated value. Experimental results have shown that the estimated speed successfully converged to measured one. Simulation studies are performed in MATLAB, before implementing the proposed observer with rotor flux oriented control for the induction machine. The observer constants and the control parameters are tuned based on this simulation results. The comparative results and related overall conclusions are presented accordingly.

Vector Control Of An AC Brushless Servomotor Using A Custom-Designed Motion Control Card

In this study, vector control of an AC brushless servomotor is performed using the current controlled, voltage source inverter and hysteresis PWM method. Using vector control, three phase variables are transformed on the synchronously rotating d and q axis, and control can be performed as in the DC motor. In order to generate PWM signals, an error value is calculated by comparing the current reference and actual current, and it is used as an input for hysteresis control. Then, the voltage vector is obtained, and the motor is driven by using the inverter to follow current reference values. Finally the servomotor speed is controlled by using this card, and results are presented. Using this custom-designed motion control card, high performance drive systems and complex algorithms can be developed. Since the proposed control system is very flexible, it is also applicable for studies on sensorless servomotor control by only modifying the software. Therefore in this paper, sensorless speed control results with ANN are also presented

General comparison of the electrical transportation systems that are fed with 1/spl times/25 kV or 2/spl times/25 kV and expectations from these systems

In electrical transportation systems which are fed from interconnected AC networks, the voltage of the conductor is 25 kV, frequency is 50 Hz or 60 Hz. Power need depends on the number of the cars and the density of traffic. In modem fast trains it can be seen that the power is 12-15 MW per car. Beside technical needs, all systems economy is an important concept. Two scenarios for providing of energy of high power traffic are considered: (a) with returning conductor in 1/spl times/25 kV systems, and (b) with autotransformer in 2/spl times/25 kV systems. If there is no added returning conductor in 1/spl times/25 kV systems, there will be some unwanted effects between transportation system conductor and signalization conductor. The current which passes over earth to substation causes these effects. There is a conductor that is serially connected with transformers, in order to limit this returning current so this current passes over this conductor. When the line current increases, the voltage drop increases. We assume that the phase disconnection place which is necessary for interconnected network feeding is next to the substation for comparison of both basic systems. In this condition, substation transformers are connected with the three phase network, so asymmetrical load of interconnected AC networks can be decreased. Neutral areas usually are placed between two wired stations in a free way.

The programme in which we calculate the motor's power, that are used in electrical transportation systems, by changing parameters of the motor's power formula and result curves

Factors which directly affect the power of the motor which will be located in the electrical vehicle, are maximum speed, travelling speed, distance between the stops, and acceleration of travelling. There is a relationship between these four factors which affect the motor power. We should keep in view the other factors which affect the power directly in order to calculate the motor power correctly. These are resistance of the travel, resistance of the road, and rate of cogwheel encircling etc. In the short distance transportation systems, because of constant speed the motor will be overheated and this can affect the choice of the motor power. But because of the short travel time this effect can be omitted. Starting and acceleration of the vehicle are more important than over-heating in the short distance transportation. This peculiarity must not be regarded and we should add 15% of the calculated power to it. While calculating the power, also overloading of the vehicle in travel must be kept in view. By making tables which shows the overload degrees we can make our calculations easily and the perpetual power can be calculated.