Papers by Davood A. Khaburi
IET Electrical Systems in Transportation, 2016
AC-DC converter switches of the drive train of series hybrid electric vehicles (SHEVs) are genera... more AC-DC converter switches of the drive train of series hybrid electric vehicles (SHEVs) are generally exposed to the possibility of outbreak open-phase faults because of troubles with the switching devices. In this framework, the present study proposes an artificial neural network (ANN)-based method for fault diagnosis after extraction of a new pattern. The new pattern under AC-DC converter failure in view of SHEV application has been used for train-proposed ANN. To achieve this goal, four different levels of switches fault are considered on the basis of both simulation and experimental results. Ensuring the accuracy and generalisation of the introduced pattern, several parameters have been considered, namely: capacitor size changes, load, and speed variations. The experimental results validate the simulation results thoroughly.
IEEE Transactions on Power Electronics, 2017
Predictive torque control (PTC) is based on the prediction of motor torque and stator flux for al... more Predictive torque control (PTC) is based on the prediction of motor torque and stator flux for all possible voltage vectors of power converter. These predictions are derived from a mathematical model of the motor that depends on the motor parameters. But, these parameters may not match with their actual values. These parametric uncertainties lead to inaccurate predictions of torque and stator flux and affect the performance of the predictive algorithm. This paper presents a modified PTC for a permanent magnet synchronous motor to reduce the torque ripple at the presence of parametric uncertainty by improving the prediction accurateness. Simulation and experimental results are provided to show the effect of the proposed method.
The 6th Power Electronics, Drive Systems & Technologies Conference (PEDSTC2015), 2015
This paper presents a new predictive direct torque and stator flux control of a permanent magnet ... more This paper presents a new predictive direct torque and stator flux control of a permanent magnet synchronous machine by a matrix converter. Unlike conventional direct torque control for permanent magnet machine that only 18 actives voltage vectors of matrix converter with fix direction are used, in the proposed predictive control all 27 possible switching states including fixed direction voltage vectors, zero voltage vectors and also rotational voltage vectors are used to control the machine. So, the number of voltage vectors to control increases that leads to faster dynamic torque response and lower ripple of torque and flux. Furthermore, an extension of the predictive control is proposed to make it more efficient. Simulation results which confirm the good performance of the proposed methods are presented.
2014 IEEE 23rd International Symposium on Industrial Electronics (ISIE), 2014
ABSTRACT The capability curves are used for loading the synchronous generators as a useful and es... more ABSTRACT The capability curves are used for loading the synchronous generators as a useful and essential tool. Moreover, one of the important applications of the capability curves is setting the relays. The main purpose of the proper loading and accurate setting of the relays is stable operating of the synchronous generators in desired margins. Therefore, the accurate calculation of the curves is significant. Although in the papers some methods and formula for calculating and drawing the capability curves have been presented, the obtained results do not coincide with the original capability curves provided by the manufacturers. It could be potentially because of disregarding the real conditions of synchronous generators such as saturation, temperature, mechanical considerations, altitude and etc. Also, there is no complete source about the capability curves which cover all parts of the curve. In this paper, in addition to briefly assess all parts of the capability curve, the latter is precisely calculated by taking into account all parameters and operational conditions of the generator. The results in the armature current limit and the under-excitation limit are in agreement with the original capability curves provided by the manufacturers. In spite of this coincidence, the over-excitation part of the graph drawn on the basis of the above-mentioned considerations and calculations does not follow the manufacturer's curves, although the conditions and limitations of the generator are considered. Accordingly, in this paper, a new simple and applicable procedure is proposed for calculating the over-excitation part of the curve, based on authors' experience in designing the synchronous generators. The results of the calculations are in good agreement with over-excitation limit of the manufacturers' curves. Simplicity, fast calculation time, precision and error minimization main features of this method.
2014 IEEE 23rd International Symposium on Industrial Electronics (ISIE), 2014
ABSTRACT This paper presents an introduction toward train movement as well as relationship among ... more ABSTRACT This paper presents an introduction toward train movement as well as relationship among wheel and train's speeds, and defines the notion of wheel slip including two different operation regions designated as creep and wheelspin areas holding stable and unstable characteristics, respectively. Since the equations of movements must be solve simultaneously, the model of wheel and slip is derived by integrating the corresponding equations of movements. Besides, the block diagram of train's speed control is shown in this paper. As wheels and rails are constructed from iron, the friction among them is weak. Consequently, the operation point of speed control system may be in either creep or wheelspin areas regarding the values of driving torque compared to the value of maximum adhesion torque. Simulation results demonstrate the advantages of maximum adhesion control in train's propulsion system minimizing the acceleration time as well as the wheel and rail sublation.
This paper focuses on studying the Solid-State Transformer (SST) and proposing a control strategy... more This paper focuses on studying the Solid-State Transformer (SST) and proposing a control strategy for its input stage. The conventional low-frequency transformers suffer some drawbacks such as uncontrolled voltages and currents, high sensitivity to harmonics, low voltage quality in saturation conditions and so on. The solid-state transformer consists of several power electronic converter stages and as it is designed to be utilized as the power supply in electric train applications in this research, it is considered to be step-down and only has a DC output. Therefore, the studied configuration only consists of rectification and DC-DC step-down conversion stages. The main contribution of this paper is to propose a hybrid method based upon the Model Predictive Control (MPC) approach in order to balance the capacitor voltages and also control the power factor of input rectifier. The suggested strategy provides some advantages compared to other methods such as simple algorithm, significa...
Proceedings of the 2011 14th European Conference on Power Electronics and Applications, 2011
In this paper an improved FCS-MPC algorithm with optimized weighting factor is presented. The mai... more In this paper an improved FCS-MPC algorithm with optimized weighting factor is presented. The main goal is reducing the torque ripples for the two-level inverter utilization. The weighting factor is optimized based on dividing the control interval in two parts. The method is validated by simulations and experiments.
The term Direct Torque Control (DTC) originally is referred to a strategy which provides good tra... more The term Direct Torque Control (DTC) originally is referred to a strategy which provides good transient and steady-state performance but it has also some negative aspects, such as non accuracy of flux, torque estimator, torque and flux ripple caused by non-optimality of switching and imprecision in motor model which are known as an inherent characteristic of DTC. This paper explores reducing of flux and torque ripple with using trial and error actively as a method called Active Learning Method (ALM) in DTC for Doubly Fed Induction Machine (DFIM) which are the motors or generators having twist on both stator and rotor subsequence power is transferred between shaft and system. DFIM is linked to the grid within the stator and the rotor is fed by an Indirect Matrix Converter (IMC). The function of IMC is similar to the direct one, although it has the line and load bridges separated. We analysis the usage of four-step commutation in rectifier stage of IMC to achieve the object of the los...
2017 8th Power Electronics, Drive Systems & Technologies Conference (PEDSTC), 2017
Wind energy is one of the most promising and developed renewable energy resources. A power electr... more Wind energy is one of the most promising and developed renewable energy resources. A power electronic interface is needed in order to connect a Wind Energy Conversion System (WECS) to the load or the utility grid. Control of this interface, which consists of generator- and grid-side converters, is a very important and demanding task. The main purpose of controlling the generator-side converter is implementing Maximum Power Point Tracking (MPPT). In this paper, the conventional Hill Climbing Search (HCS) MPPT algorithm is modified using fuzzy logic theory in a way that its performance has been enhanced in terms of accuracy and speed. This modified algorithm enables the system to continuously extract the maximum energy from the wind by generating an appropriate rotor speed reference. Vienna rectifier is used as the generator-side converter due to its noticeable advantages in WECSs. A non-linear control scheme based on Sliding Mode Control (SMC) is utilized in this work for efficient s...
2017 8th Power Electronics, Drive Systems & Technologies Conference (PEDSTC), 2017
In this paper, a high step-up multi-input switched-capacitor DC-DC converter is studied for hybri... more In this paper, a high step-up multi-input switched-capacitor DC-DC converter is studied for hybrid renewable energy system applications. A modified model predictive controller is proposed for this converter in order to appropriately track the reference input currents with minimum number of switching actions. In comparison to the classical PI controllers, which are widely used in this application, the proposed controller provides notable advantages such as elimination of additional modulation stages and improving the dynamic and steady state performance. Moreover, designing PI controllers and tuning their parameters is more difficult for a multi-input converter, compared to a single-input one, since the behaviors of the multi-input converter input currents are not independent. However, the conventional predictive control scheme will result in ripple components due to its variable switching frequency performance. Therefore, some modifications are made in the design procedure to overco...
In this paper, a wind speed sensor-less Maximum Power Point Tracking (MPPT) algorithm is designed... more In this paper, a wind speed sensor-less Maximum Power Point Tracking (MPPT) algorithm is designed and applied to a Wind Energy Conversion System (WECS). This algorithm is simple, fast, efficient, and more importantly, does not require wind speed measurement. Moreover, A Multi-Layer Perceptron Neural Network (MLPNN)-based pitch angle controller is designed. When the wind speed exceeds its rated value, this controller limits the mechanical power and rotor speed to their rated values in order to protect the WECS from probable damages. A non-linear speed controller based on Integral Sliding Mode Control (ISMC) is designed to realize the MPPT. The proper performance of the combined MPPT-pitch angle control scheme is verified by simulation results. Moreover, a comparison is made between conventional PI-based pitch angle controller and the designed MLPNN-based one in this work. The results approve the superior performance of the designed controller.
Direct Torque Control is a control technique in AC drive systems to obtain high performance torqu... more Direct Torque Control is a control technique in AC drive systems to obtain high performance torque control. The conventional DTC drive contains a pair of hysteresis comparators. DTC drives utilizing hysteresis comparators suffer from high torque ripple and variable switching frequency. The most common solution to those problems is to use the space vector depends on the reference torque and flux. In this Paper The space vector modulation technique (SVPWM) is applied to 2 level inverter control in the proposed DTC-based induction motor drive system, thereby dramatically reducing the torque ripple. Then the controller based on space vector modulation is designed to be applied in the control of Induction Motor (IM) with a three-level Inverter. This type of Inverter has several advantages over the standard two-level VSI, such as a greater number of levels in the output voltage waveforms, Lower dV/dt, less harmonic distortion in voltage and current waveforms and lower switching frequencie...
IET Electric Power Applications
IEEE ACCESS, 2021
Finite Control Set Model Predictive Control (FCS-MPC), thanks to its simple and powerful concept,... more Finite Control Set Model Predictive Control (FCS-MPC), thanks to its simple and powerful concept, has been applied widely to control the multilevel converters. FCS-MPC allows the control of several objectives and can incorporate restrictions, even nonlinear, into the mathematical model of the system under consideration. However, FCS-MPC needs to evaluate all the switching states of the multilevel converter to find the best switching state to be applied in the next sampling time. For higher-level multilevel converters, this iterative action requires computational capacity that is far beyond the digital controller's capacity in the current market. This paper proposes a new predictive geometric pre-filtering strategy to reduce the iterations and computational burden without affecting the dynamic performance of FCS-MPC. This method consists of a novel pre-filtering stage that uses the predictive model of the system and geometrical properties to find the sector where the reference ve...
Electronics
In this paper, a five-level neutral-point-clamped (NPC) inverter with short-circuit fault-toleran... more In this paper, a five-level neutral-point-clamped (NPC) inverter with short-circuit fault-tolerant capability is presented. Based on the proposed approach, in order to ensure service continuity subsequent to a short-circuit fault event in a switch, two steps are carried out. First of all, destructive consequences arising from short-circuit fault in a power switch is prevented. Afterwards, according to the defected component, remedial actions are taken. The proposed strategy does not require any redundant component. The service continuity is acquired by applying a remedial control and modifying switching commands applied to the power switches. Using the proposed approach helps to restore the rated voltage and rated current at the terminal, and there is no limit for modulation index during fault-tolerant operation under remedial control. Furthermore, compared to healthy operation, harmonic content of the terminal voltage and current is not deteriorated during fault-tolerant operation....
2018 IEEE 19th Workshop on Control and Modeling for Power Electronics (COMPEL)
IEEE Transactions on Industry Applications
IEEE Journal of Emerging and Selected Topics in Power Electronics
IET Electric Power Applications
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Papers by Davood A. Khaburi