Comparison of Two Rotor Configurations by Changing the Amount of Magnet and Reluctance Components

Beser, Esra Kandemir,Camur, Sabri,Arifoglu, Birol,Beser, Ersoy The Korean Institute of Electrical Engineers 2015 Journal of Electrical Engineering & Technology Vol.10 No.1

In this paper, two rotor configurations including different amount of magnet and reluctance parts are presented. The rotors are constituted by means of a flexible hybrid motor structure. Considerable features of the hybrid structure are that the combination of the magnet and reluctance parts can be suitably modified and the mechanical angle (${\beta}$) between the parts can also be varied. Two hybrid rotor configurations have been considered in this study. First, finite element (FE) simulations were carried out and the torque behaviors of the motors were predicted. The average torque ($T_{avg}$) and maximum torque ($T_{max}$) curves were obtained from FE simulations in order to find suitable ${\beta}$. Mathematical model of the motors was formed in terms of a,b,c variables considering the amount of the magnet and reluctance parts on the rotor and simulations were performed. Rotor prototypes, motor drive and drive method were introduced. Torque profiles of the motors were obtained by static torque measurement and loaded tests were also realized. Thus, simulation results were verified by experimental study. There is a good match between predictions and measurements. The proposed motors are operated with electrical $120^{\circ}$ mode as a brushless DC motor (BLDC) and torque versus speed characteristics show a compound DC motor characteristic. The motors can be named as brushless DC compound motors.

Design and Application of a Single Phase Multilevel Inverter Suitable for using as a Voltage Harmonic Source

Beser, Ersoy,Arifoglu, Birol,Camur, Sabri,Beser, Esra Kandemir The Korean Institute of Power Electronics 2010 JOURNAL OF POWER ELECTRONICS Vol.10 No.2

This paper presents a single phase multilevel inverter for using as a voltage harmonic source. First, a single phase multilevel inverter system is presented and the structural parts of the inverter are described. In order to obtain multilevel output voltage waveforms, a switching strategy based on calculating switching angles is explained and an improved formula for determining switching angles is given. Simulation and experimental results of multilevel voltage waveforms are given for 15, 31 and 127 levels. The proposed topology does not only produce output voltages with low THD values. It also produces the required harmonic components on the output voltage. For this purpose, equations for switching angles are constituted and the switching functions are obtained. These angles control the output voltage as well as provide the required specific harmonics. The proposed inverter structure is simulated for various functions with the required harmonic components. The THD values of the output voltage waves are calculated. The simulated functions are also realized by the proposed inverter structure. By using a harmonic analyzer, the harmonic spectrums, which belong to the output voltage forms, are found and the THD values are measured. Simulation and experimental results are given for the specific functions. The proposed topology produces perfectly suitable results for obtaining the specific harmonic components. Therefore, it is possible to use the structure as a voltage harmonic source in various applications.

Analysis and Application of a Hybrid Motor Structure Convenient to Modify the Magnet and Reluctance Torques on the Rotor

Beser, Esra Kandemir,Camur, Sabri,Arifoglu, Birol,Beser, Ersoy The Korean Institute of Electrical Engineers 2012 Journal of Electrical Engineering & Technology Vol.7 No.3

This paper presents a hybrid motor prototype convenient to modify the magnet and reluctance torques. The rotor of the prototype consists of magnet and reluctance parts, so the generated torque includes both magnet and reluctance torques. A considerable feature of the motor is that the ratio of the magnet and reluctance parts can be modified on the rotor and the rotor hybridization ratio can be varied. Another important point is the mechanical angle between the parts changed by means of the suitable construction of the parts on the rotor shaft. Finite element (FE) analysis was carried out for the proposed motor and static torque measurements were realized. The FE results were compared with the experimental results. Average torque and maximum torque values were obtained and three dimensional 3-D graphs were formed by using the experimental data. It is possible to make different combinations by changing the parts and the angle between the parts due to the proposed motor. So the magnet and reluctance torques are modified and different combinations give different torque behavior.

Design and Application of a Single Phase Multilevel Inverter Suitable for using as a Voltage Harmonic Source

Ersoy Beser,Birol Arifoglu,Sabri Camur,Esra Kandemir Beser 전력전자학회 2010 JOURNAL OF POWER ELECTRONICS Vol.10 No.2

This paper presents a single phase multilevel inverter for using as a voltage harmonic source. First, a single phase multilevel inverter system is presented and the structural parts of the inverter are described. In order to obtain multilevel output voltage waveforms, a switching strategy based on calculating switching angles is explained and an improved formula for determining switching angles is given. Simulation and experimental results of multilevel voltage waveforms are given for 15, 31 and 127 levels. The proposed topology does not only produce output voltages with low THD values. It also produces the required harmonic components on the output voltage. For this purpose, equations for switching angles are constituted and the switching functions are obtained. These angles control the output voltage as well as provide the required specific harmonics. The proposed inverter structure is simulated for various functions with the required harmonic components. The THD values of the output voltage waves are calculated. The simulated functions are also realized by the proposed inverter structure. By using a harmonic analyzer, the harmonic spectrums, which belong to the output voltage forms, are found and the THD values are measured. Simulation and experimental results are given for the specific functions. The proposed topology produces perfectly suitable results for obtaining the specific harmonic components. Therefore, it is possible to use the structure as a voltage harmonic source in various applications.

Comparison of Two Rotor Configurations by Changing the Amount of Magnet and Reluctance Components

Esra Kandemir Beser,Sabri Camur,Birol Arifoglu,Ersoy Beser 대한전기학회 2015 Journal of Electrical Engineering & Technology Vol.10 No.1

In this paper, two rotor configurations including different amount of magnet and reluctance parts are presented. The rotors are constituted by means of a flexible hybrid motor structure. Considerable features of the hybrid structure are that the combination of the magnet and reluctance parts can be suitably modified and the mechanical angle (β) between the parts can also be varied. Two hybrid rotor configurations have been considered in this study. First, finite element (FE) simulations were carried out and the torque behaviors of the motors were predicted. The average torque (Tavg) and maximum torque (Tmax) curves were obtained from FE simulations in order to find suitable β. Mathematical model of the motors was formed in terms of a,b,c variables considering the amount of the magnet and reluctance parts on the rotor and simulations were performed. Rotor prototypes, motor drive and drive method were introduced. Torque profiles of the motors were obtained by static torque measurement and loaded tests were also realized. Thus, simulation results were verified by experimental study. There is a good match between predictions and measurements. The proposed motors are operated with electrical 120° mode as a brushless DC motor (BLDC) and torque versus speed characteristics show a compound DC motor characteristic. The motors can be named as brushless DC compound motors.

Analysis and Application of a Hybrid Motor Structure Convenient to Modify the Magnet and Reluctance Torques on the Rotor

Esra Kandemir Beser,Sabri Camur,Birol Arifoglu,Ersoy Beser 대한전기학회 2012 Journal of Electrical Engineering & Technology Vol.7 No.3

This paper presents a hybrid motor prototype convenient to modify the magnet and reluctance torques. The rotor of the prototype consists of magnet and reluctance parts, so the generated torque includes both magnet and reluctance torques. A considerable feature of the motor is that the ratio of the magnet and reluctance parts can be modified on the rotor and the rotor hybridization ratio can be varied. Another important point is the mechanical angle between the parts changed by means of the suitable construction of the parts on the rotor shaft. Finite element (FE) analysis was carried out for the proposed motor and static torque measurements were realized. The FE results were compared with the experimental results. Average torque and maximum torque values were obtained and three dimensional 3-D graphs were formed by using the experimental data. It is possible to make different combinations by changing the parts and the angle between the parts due to the proposed motor. So the magnet and reluctance torques are modified and different combinations give different torque behavior.

Design and Application of a Photovoltaic Array Simulator with Partial Shading Capability

Beser, Ersoy The Korean Institute of Power Electronics 2019 JOURNAL OF POWER ELECTRONICS Vol.19 No.5

PV system performance is dependent on different irradiations and temperature values in addition to the capability of the employed PV inverter / maximum power point tracker (MPPT) circuit or algorithm. Therefore, it would be appropriate to use a PV simulator capable of producing identical repeatable conditions regardless of the weather to evaluate the performance of inverter / MPPT circuits and algorithms. In accordance with this purpose, a photovoltaic (PV) array simulator is presented in this paper. The simulator is designed to generate current-voltage (I-V) and power-voltage (P-V) curves of a PV panel. Series connected cascaded modules constitute the basic part of the simulator. This feature also allows for the modeling of PV arrays since the number of modules can be increased and high voltage values can be reached with the simulator. In addition, the curves obtained at the simulator output become similar to the actual curves of sample PV panels with an increase in the number of modules. In order to show the validity of the proposed simulator, it was simulated for various situations such as panels under full irradiance and partial shading conditions. After completing simulations, experiments were realized to support the simulation study. Both simulation and experimental results show that the proposed simulator will be very useful for researchers to carry out PV studies under laboratory conditions.

Design and Application of a Photovoltaic Array Simulator with Partial Shading Capability

Ersoy Beser 전력전자학회 2019 JOURNAL OF POWER ELECTRONICS Vol.19 No.5

PV system performance is dependent on different irradiations and temperature values in addition to the capability of the employed PV inverter/ maximum power point tracker (MPPT) circuit or algorithm. Therefore, it would be appropriate to use a PV simulator capable of producing identical repeatable conditions regardless of the weather to evaluate the performance of inverter/ MPPT circuits and algorithms. In accordance with this purpose, a photovoltaic (PV) array simulator is presented in this paper. The simulator is designed to generate current-voltage (I-V) and power-voltage (P-V) curves of a PV panel. Series connected cascaded modules constitute the basic part of the simulator. This feature also allows for the modeling of PV arrays since the number of modules can be increased and high voltage values can be reached with the simulator. In addition, the curves obtained at the simulator output become similar to the actual curves of sample PV panels with an increase in the number of modules. In order to show the validity of the proposed simulator, it was simulated for various situations such as panels under full irradiance and partial shading conditions. After completing simulations, experiments were realized to support the simulation study. Both simulation and experimental results show that the proposed simulator will be very useful for researchers to carry out PV studies under laboratory conditions.

Half-bridge Cascaded Multilevel Inverter Based Series Active Power Filter

Karaarslan, Korhan,Arifoglu, Birol,Beser, Ersoy,Camur, Sabri The Korean Institute of Power Electronics 2017 JOURNAL OF POWER ELECTRONICS Vol.17 No.3

A new single phase half-bridge cascaded multilevel inverter based series active power filter (SAPF) is proposed. The main parts of the inverter are presented in detail. With the proposed inverter topology, any compensation voltage reference can be easily obtained. Therefore, the inverter acts as a harmonic source when the reference is a non-sinusoidal signal. A 31-level inverter based SAPF with the proposed topology, is manufactured and the voltage harmonics of the load connected to the point of common coupling (PCC) are compensated. There is no need for a parallel passive filter (PPF) since the main purpose of the paper is to represent the compensation capability of the SAPF without a PPF. It is aimed to compensate the voltage harmonics of the load fed by a non-sinusoidal supply using the proposed inverter. The validity of the proposed inverter based SAPF is verified by simulation as well as experimental study. The system efficiency is also measured in this study. Both simulation and experimental results show that the proposed multilevel inverter is suitable for SAPF applications.

Level Number Effect on Performance of a Novel Series Active Power Filter Based on Multilevel Inverter

Karaarslan, Korhan,Arifoglu, Birol,Beser, Ersoy,Camur, Sabri The Korean Institute of Electrical Engineers 2018 Journal of Electrical Engineering & Technology Vol.13 No.2

This paper presents a single-phase asymmetric half-bridge cascaded multilevel inverter based series active power filter (SAPF) for harmonic voltage compensation. The effect of level number on performance of the proposed SAPF is examined in terms of total harmonic distortion (THD) and system efficiency. Besides, the relationship between the level number and the number of switching device are compared with the other multilevel inverter topologies used in APF applications. The paper is also aimed to demonstrate the capability of the SAPF for compensating harmonic voltages alone, without using a passive power filter (PPF). To obtain the required output voltage, a new switching algorithm is developed. The proposed SAPF with levels of 7, 15 and 31 is used in both simulation and experimental studies and the harmonic voltages of the load connected to the point of common coupling (PCC) is compensated under two different loading conditions. Furthermore, very high system efficiency values such as 98.74% and 96.84% are measured in the experimental studies and all THD values are brought into compliance with the IEEE-519 Standard. As a result, by increasing the level number of the inverter, lower THD values can be obtained even under high harmonic distortion levels while system efficiency almost remains the same.