Khomfoi, Surin
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Preferred name
Khomfoi, Surin
Alternative Name
Khomfoi, S.
Main Affiliation
Email
surin.kh@kmitl.ac.th
7 results
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Item type:Publication, Fault detection and reconfiguration technique for cascaded H-bridge 11-level inverter drives operating under faulty condition(2007-12-01); Tolbert, Leon M.A fault detection and reconfiguration technique for a cascaded H-bridge 11-level inverter drives during faulty condition is proposed in this paper. The ability of cascaded H-bridge multilevel inverter drives (MLID) to operate under faulty condition is also discussed. Output phase voltages of a MLID can be used as a diagnostic signal to detect faults and their locations. AI-based techniques are used to perform the fault classification. A neural network (NN) classification is applied to the fault diagnosis of a MLID system. Multilayer perceptron (MLP) networks are used to identify the type and location of occurring faults. The principal component analysis (PCA) is utilized in the feature extraction process to reduce the NN input size. The genetic algorithm (GA) is also applied to select the valuable principal components to train the NN. A reconfiguration technique is also developed. The developed system is validated with simulation and experimental results. The developed fault diagnostic system requires about 6 cycles (∼100 ms at 60 Hz) to clear an open circuit and about 9 cycles (∼150 ms at 60 Hz) to clear a short circuit fault. The experiment and simulation results are in good agreement with each other, and the results show that the developed system performs satisfactorily to detect the fault type, fault location, and reconfiguration. © 2007 IEEE. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, A 5-level cascaded hybrid multilevel inverter for interfacing with renewable energy resources(2009-10-22); Aimsaard, ChatrchaiA 5-level cascaded hybrid multilevel inverter for interfacing with renewable energy resources is developed. The objective of this research is to propose an alternative topology of hybrid cascaded multilevel inverter applications. The modified PWM technique is also developed to reduce switching losses. Also, the proposed topology can reduce the number of required power switches compared to a traditional cascaded multilevel inverter. PSIM (PowerSim) and Simulink/MATLAB are used to simulate the circuit operation and control signal. The 3-kW prototype is developed. The results show that this alternative topology can be applied for high power applications as a multilevel inverter. ©2009 IEEE. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Fault diagnosis and reconfiguration for multilevel inverter drive using AI-based techniques(2007-12-01); Tolbert, Leon M.A fault diagnostic and reconfiguration method for a cascaded H-bridge multilevel inverter drive (MLID) using artificial-intelligence-based techniques is proposed in this paper. Output phase voltages of the MLID are used as diagnostic signals to detect faults and their locations. It is difficult to diagnose an MLID system using a mathematical model because MLID systems consist of many switching devices and their system complexity has a nonlinear factor. Therefore, a neural network (NN) classification is applied to the fault diagnosis of an MLID system. Multilayer perceptron networks are used to identify the type and location of occurring faults. The principal component analysis is utilized in the feature extraction process to reduce the NN input size. A lower dimensional input space will also usually reduce the time necessary to train an NN, and the reduced noise can improve the mapping performance. The genetic algorithm is also applied to select the valuable principal components. The proposed network is evaluated with simulation test set and experimental test set. The overall classification performance of the proposed network is more than 95%. A reconfiguration technique is also proposed. The proposed fault diagnostic system requires about six cycles to clear an open-circuit or short-circuit fault. The experimental results show that the proposed system performs satisfactorily to detect the fault type, fault location, and reconfiguration. © 2007 IEEE. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Influence of PWM characteristics on the core losses due to harmonic voltages in PWM fed induction motors(2000-01-01); ; Viriya, P.The paper focuses on mechanisms of harmonic core losses due to PWM characteristics. The influence of PWM characteristics such as switching frequency, modulation depth and PWM strategy on core losses has been examined. The investigation into harmonic core losses based on no-load input power measurement with minimized rotor copper loss and rotational loss has been made. The experimental results show that the increment of core losses due to PWM harmonic voltages is significant compared to a sinusoidal supply and the modulation depth has significant effect on machine core losses. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Hybrid cascaded multilevel inverter with PWM control method(2008-09-29); - Some of the metrics are blocked by yourconsent settings
Item type:Publication, A reconfiguration technique for cascaded H-bridge multilevel inverter drives(2008-10-06)A reconfiguration technique for cascaded H-bridge multilevel inverter drives (CMID) is proposed in this paper. The reliability of the CMID can be improved by using the proposed reconfiguration technique. The proposed technique is very simple to implement because the proposed technique is based on digital logic gate; a simple AND gate and OR gate can be implemented for this reconfiguration method. The effects and limitations of using the developed reconfiguration technique at high modulation index are also addressed. © 2008 IEEE. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Elimination of harmonics in a five-level diode-clamped multilevel inverter using fundamental modulation(2007-12-01)