Güngör Bal

A highly effective load adaptive servo drive system for speed control of travelling-wave ultrasonic motor

This paper presents a highly effective load adaptive drive system to control the speed of a travelling-wave ultrasonic motor. The motor driver was built based on the two-phase high-frequency inverter using the mechanical resonant frequency of the ultrasonic motor. To digitally control the drive system, a TMS320F243 digital signal processor was adapted to the driver. The developed system includes two feedback loops; speed control loop and feedback voltage-resonant frequency tracking loop. The driving frequency was used as a control input to control the motor. Direct pulse-width modulation (PWM) control was used to obtain the required driving frequency. The developed drive system was experimentally tested under several operating conditions. The obtained results demonstrated the effectiveness of the drive system for high performance drive applications.

Parallel DC-AC conversion system based on separate solar farms with MPPT control

Three separate solar farms that provide 15 kW power for each farm are modelled using Matlab Simulink real-time analysis software in this study. Each solar farm models are constituted by connecting 170W photovoltaic (PV) panels and energy conversion is performed with maximum power point tracking (MPPT) algorithms in each converter. The MPPT algorithm utilized in the control step of converters is developed using Perturb and Observe (P&O) structure. The converters used in the solar farms are designed in boost converter topology while output voltages are collected in DC busbar with parallel connection of converters. The converters are connected to busbar over interphase transformers (IPT). The DC busbar voltage is applied to a full bridge inverter to generate 3-phase AC voltages at the output of inverter. The three-phase inverter is controlled with sinusoidal pulse width modulation (SPWM) scheme, which is developed with phase shifted carrier signals. The load of inverter is set to an adjustable load, which is capable to be increased up to 50 kW. The measurement points seen in the Simulink design are analysed in detail. Each measurement points definition and screen captures are also evaluated in the study.

A web based real time speed control experiment on ultrasonic motor for educational purposes

This study introduces original system architecture for the Web based remote experimentation applications for e-learning systems. The speed control of a traveling wave ultrasonic motor (USM) is achieved as a remote experimental study over the Internet to illustrate the architecture. For this reason, a microcontroller based digitally controlled drive system for the USM is designed firstly. A data acquisition board is then used to perform data transferring and control operations between the server and the drive system. Data obtained from experimental set is analyzed in the MATLAB program installed on the server. Similarly, MATLAB Web server (MWS) software is used to send and receive data over the Internet. Since all operation steps are executed from the server, clients do not need any special hardware or software unit. Thus, the system developed has an independent structure for the clients. Remotely located clients can operate and control the motor and conduct the experiment. Additionally, real laboratory environment and the experimental set can be monitored on the client computerpsilas screen while the experiment is being operated. The results obtained from the tests show that the system developed has significant features such as simplicity, sensitivity, reliability and speedy. Accordingly, the system presented can be adapted to e-learning systems easily as an effective tool for remote experimentation.

Internet based virtual electric machine lab: Switched reluctance motor

In this study, distance accessed virtual laboratory for an electric machine was established. For this purpose a switched reluctance motor (SRM) was chosen as an example. Simulation of a SRM was achieved with using Matlab&Simulink package program. A LabVIEW program was used to build an Interface between internets and the simulation program. Any student or user is able to access these educational tools from any place having an internet connection and can change necessary parameters of SRM and also see behavior of SRM with help of graphics on screen.

Nonlinear modelling of a switched reluctance drive based on neural networks

Switched reluctance motors (SRMs) are almost always operated within the saturation region for a very large operation region. This yields very strong nonlinearities, which makes it very difficult to derive a comprehensive mathematical model for the behaviour of the machine. Artificial neural networks (ANNs) have been used to overcome such problems. This paper presents ANNs as a new tool to handle one of the key problems in an SRM based drive system. A back propagation algorithm is used to train the network. To explore the validity of the proposed technique, the results of ANNs were compared with the experimentally measured results. The comparison between these results have validated the applicability of the proposed method.<<ETX>>

Protection of Induction Motor Using PLC

The goal of this paper is to protect induction motors against possible failures by increasing the reliability, the efficiency, and the performance. The proposed approach is a sensor-based technique. For this purpose, currents, voltages, speed and temperature values of the induction motor were measured with sensors. When any fault condition is detected during operation of the motor, PLC controlled on-line operation system activates immediately. The performance of the protection system proposed is discussed by means of application results. The motor protection achieved in the study can be faster than the classical techniques and applied to larger motors easily after making small modifications on both software and hardware.

A Novel Control Technique for Soft-switching Sinusoidal Pulse Width Modulation Inverter

Abstract This article presents a new zero-current switching technique for a single-phase full-bridge sinusoidal pulse width modulation inverter. Two auxiliary switches and a resonant branch are attached to a conventional single-phase full-bridge inverter. The resonant branch can be controlled independently from the main power switches. This technique decreases turn-on and turn-off switching losses and does not require any snubber capacitor. The technique can be applied to DC/DC converters and DC/AC inverters with suitable switching algorithms. Both theoretical analysis and application of the proposed technique have been realized. It was seen that the proposed technique has 45% less switching losses and better performance than the hard-switching technique for the same load and switching frequency. The experimental results also approve the effectiveness of the zero-switching technique.

Design and application of a novel high precision and low cost electronic tachogenerator for sensor-based brushless direct current motor drivers

This study presents a precise speed control method for Brushless Direct Current (BLDC) Motors using an electronic tachogenerator (ETg) instead of an electro-mechanical tachogenerator. Most commonly used three-phase BLDC motors have three position sensors for rotor position data to provide commutation among stator windings. Aforementioned position sensors are usually Hall-effect sensors delivering binary-high and binary-low data as long as the motor rotates. These binary sets from three Hall-effect sensors can be used as an analogue rotor speed signal for closed loop applications. Each position sensor signal is apart from 120 electrical degrees. By using an electronic circuitry, a combination of position sensor signals is converted to the analogue signal providing an input to a PI speed controller. To implement this, a frequency to voltage converter has been used in this study. Then, the analogue speed signal has been evaluated as rotor speed data in comparison with the reference speed. So, an ETg system has been successfully achieved in place of an electro-mechanical tachogenerator for BLDC motor speed control. The proposed ETg has been tested under various speed conditions on an experimental setup. Employed tests and obtained results show that the proposed low-cost speed feedback sub-system can be effectively used in BLDC motor drive systems. Through the proved method and designed sub-system, a new motor controller chip with a speed feedback capability has been aimed.

A Parameter Determination System for Wind Turbines Based on Naive Bayes Classification Algorithm

Among the renewable energy types, wind energy gets popularity in these days. To install a new wind energy turbine, measurement and evaluation of the meteorological data are quite important. In this paper, a novel system is developed for the installation of wind turbines. Firstly, necessary data including the speed and the direction of wind, the solar insolation, the ultraviolet radiation and the rainfall are received from a meteorology station, and then data acquired are converted into useful information using a rule-based inference mechanism. Finally, the useful information obtained are evaluated in a Naive Bayes algorithm. The power and the size of wind turbine are determined automatically using data measured. Thus, some complicated calculations including more than parameters related to fields where the large-sized wind turbines will be installed can easily be accomplished by means of the powerful decision support system developed.

Implementation of a call system with power line communication

In this study, a communication system to send an eight-bits data to the receiver via an energy transmission (power) line was designed and tested. On the transmitter three buttons were used to send three different data to the line. On the receiver side, a buzzer and an LCD screen were used for the voice warning and for indication of the button which a call is activated. There is no need of additional inter-line between the transmitters and receivers. By using this setup, one preserves much time, labor and cost. The prototype of the developed setup was successfully operated in a flat.