Sharif Digital Repository

In today’s world, people’s tendency to use their own vehicles is relatively high since private cars provide more convenience, better safety, and better time management than public transportation, but cause more traffic in the streets. Ride-sharing is one of the management tools that has attracted a lot of attention in recent years to mitigate the traffic congestion. Also, electric vehicles are used for public transportation in many parts of the world to achieve a sustainable environment. In this study, we assume that passengers’ origin, destination, and preferred time windows for pick-up and drop-off are known in advance. The aim of the study is to determine the sequence of visiting travel... 

People are increasingly using private vehicles as a result of the ever-increasing population growth worldwide and the increasing number of travel requests through the transportation network. There are many problems associated with the use of private vehicles on the transportation network, including traffic congestion and air pollution. To address the existing demand, decision-makers have always sought effective modes to respond to the existing situation. For passengers, the proposed modes of transportation should offer the same level of convenience and affordability as a private vehicle. In recent years, shared mobility has become increasingly popular. This mode of transportation has... 

converters, the different configurations for matrix converters are proposed. In this thesis, a one-phase to three-phase matrix converter is used to control in three-phase induction motor. Different control methods are proposed to control the induction motor. The novel control methods include close loop speed and converter output current controls of induction motor are proposed based on SPWM. The structure of indirect matrix converter for the mentioned application also investigated. Moreover, three usual method of control of induction motor: DTC (Direct Torque Control), FOC (Field Oriented Control) and Space Vector Modulation are applied to the single to three- phase matrix converter. Each of... 

Reduction of power converters’ cost is one of the most important efforts to improve machines control systems. In this way, some new topologies for power electronic converters have been proposed. Among various topologies, four switch three phase inverter (FSTPI) thanks to the simple circuit, low cost, minimized conduction and switching losses and high reliability has attracted much attention recently. In this thesis, direct torque control (DTC) method is utilized to control of four switch inverter fed induction motor. In this way, in order to decrease flux and torque ripple and achieving constant switching frequency, a new Discrete Space Vector Modulation (DSVM) method have been proposed in... 

Multilevel converters are considered recently as one of the industrial solutions for high-power and power quality demanding applications. Casacade H-Bridge (CHB) converter is one of the well known topologies among multilevel converters. CHB converter is characterized by its high modularity allowing its power to be easily increased. Modularity also allows any faulty cell to be isolated, so the load can be fed by the remaining operative cells, which leads to an unbalanced output voltage of the CHB converter. To avoid the unbalanced operation, recently a solution based on modifying the phase and the magnitude of the voltage refereces has been proposed. This thesis presents a method to control... 

Today, various industries rely on high-power, high-voltage induction motors for diverse applications. Given the critical role these motors play, any reduction in their lifespan or occurrence of failures can lead to substantial financial losses and even pose risks to lives. One significant factor influencing motor life is the temperature of its components. Manufacturers strive to enhance motor power while minimizing dimensions for economic reasons, but this increases power density and subsequent losses, elevating motor temperature. Consequently, thermal analysis becomes crucial, posing a significant challenge for companies producing high-power induction motors. In this study, a thermal model... 

In this thesis, a model is presented to detect and monitor the rotor bar's condition of large motors. This proposed model uses two diagnostic methods MCSA and ZCT, to extract the fault components. The input of the proposed model is only the motor current at two levels of 80% and 100% of the nominal motor load, which by using the two methods MCSA and ZCT and making changes in how to use them can be the disadvantages of other methods such as incorrect detection of rotor bars in Large motors with variable load, the harmonical stator voltage (or the presence of the drives) and asymmetric conditions. The extracted components are classified using two learnable algorithms, the k-NN algorithm and... 

Ilam refinery has three synchronous generator units each with a capacity of 26.5 MVA and two six-phase LCI-fed synchronous compressors, each with a capacity of 8 MW. Generators of Ilam gas refinery have instability issue in case of island operation. With launching one generator unit and then connecting two compressors the instability problem and tripping of the generators appear. Given the importance of this issue, various tests and corresponding measurements in both electrical and mechanical aspects were carried out at the plant in on-grid and island operations to analyze the cause of instability phenomena. The mechanical part of tests analyses the frequency of oscillations and vibration in... 

Constantly rising fossil fuel consumption and the resulting air pollutants have caused hybrid electric vehicles to be considered as the most efficient mid-term solution for decreasing problems resulting from environmental pollutions and rising fuel prices. Various types of hybrid electric vehicles and power transmission schemes are studied in this thesis. Electric motors utilized in electric vehicles and hybrid electric vehicles such as induction motor, brushless permanent magnet motor, DC motor and switched reluctance motors are investigated based on previous studies and researches, and are compared for all basic criteria. For completing the comparison procedure and selecting the most... 

Video games, as a form of entertainment, have gained widespread attention and usage among all age groups, especially children and adolescents. With a wide variety of game genres and difficulty levels, they offer the opportunity to assess cognitive performance in individuals based on inter-individual differences and variable characteristics such as age, gender, and literacy level. The aim of this research is to study the brain response and gaze dynamics of individuals in a computer game (endless runner) based on electroencephalogram (EEG) signals and eye tracker data. The research process consists of two phases: "Brain Signal Processing in Motor Imagery Tasks" and "Reward and Punishment... 

Due to the huge contribution of commercial transportation in creating pollutants, if various companies around the world are able to use electric vehicles, a big step will be taken in the direction of reducing pollution and expanding green supply chains. Despite the development of the infrastructure of electric vehicles and their use to transport goods and serve customers, this clean technology still faces many challenges.Among the weaknesses that researchers have been trying to deal with since the formation of electric vehicle routing is their low range of motion. After examining the way of using commercial electric vehicles, this research introduces the routing model of electric vehicles... 

The fast growth of technologies, most of which depend on natural sources of energy, has resulted in colossal fossil fuel consumption. In this regard, many solutions have been suggested to alleviate the side effects such as air pollution and global warming. Among these solutions, mobile storages like electric vehicles (EVs) and renewable generations have grown significantly due to being more applicable. The uncoordinated operation and uncertain nature of these distributed energy resources (DERs) can bring forward new challenges and issues to the power system operators. Thus, in many cases, it is more efficient to co-operate them in a hybrid system. In this thesis, we address a virtual power plant... 

In the past few decades, a considerable number of researches is devoted to study different challenges of ridesharing systems. Thus, this paper presents a mathematical optimization model to find the exact solution of the dynamic dial-a-ride problem with a fleet of electric autonomous vehicles and charging stations. Furthermore, time windows at which model strives to serve trip requests, are defined over origin and destination of passengers. Contrary to many previous works, charging behavior of vehicle battery at charging station is modeled to follow the actual nonlinear function in real world. In addition, vehicles are able to charge the battery whether fully or partially, whichever is more... 

Flying has fascinated mankind for ages. Nowadays, planar actuators are performing the same task as that, once a dream, of a flying magic carpet found in Persian mythology. Magnetically levitated planar actuators (MLPAs) consist of two parts; a moving part, and a stationary part. In most applications the moving part which is an array of permanent magnets (PMs) produces a magnetic flux density in the air-gap, and the stationary part, an array of current carrying coils, produces force and torque when it is exposed to the magnetic flux of the PM array. These actuators have been utilized in industry in applications where precise positioning is important. In recent years however, they have found... 

This dissertation focuses on modeling human hand movements post-stroke to understand rehabilitative interventions. The model consists of a multi-layer neural network as the motor cortex in the brain and a two-degree freedom biomechanical model with six muscles for the simulation of hand movement in the horizontal plane. A passive robotic device has been designed and manufactured to record planar hand movements. Movements during reaching tasks have been recorded in 24 chronic stroke patients, as well as 18 healthy subjects, using the robotic device. Statistical analysis of the data showed that movements in a particular direction (NW-SE) are more sensitive to stroke, improve after... 

The use of electric vehicles is increasing day by day due to the reduction of pollution, reduction of fuel costs, higher efficiency, etc. Increasing the distance traveled in each charging period of the electric vehicle battery pack and increasing the lifetime of the battery cells are the most important challenges facing the electric vehicle industry. In electric vehicles, Li-Ion battery cells are used to store energy, so to improve these challenges, we first need to carefully examine the behavior of these cells with the various conditions that occur during operation to design other circuits such as balancing circuits, Battery management system, etc. In this thesis, first a model is proposed... 

Nowadays, piezoelectric motors are used as one of the suitable options in the modern motion control field and precise positioning systems due to their suitable functional characteristics such as high power to weight ratio, fast dynamic response, direct drive motion, integrated structure without backlash and possibility of miniature design. Accordingly, the present dissertation is defined in order to develop a comprehensive path for modeling, analysis and optimization of the ultrasonic piezoelectric motors. In this study, the focus is on the ultrasonic motors with an elliptical structure, but the results can be used for other structures as well. In the present work, the process of modeling of... 

Pumps are widely used in oil and gas industry. Therefore condition monitoring for this type of equipment is very important. The motor current signature analysis (MCSA) technique as one of the condition monitoring techniques is very effective in the industry, but it is less used in industry. All conventional methods require additional sensors to be installed in the system; current signature analysis as a sensorless method can reduce the cost of condition monitoring. In this study, motor current signature analysis technique was used to diagnosis a centrifugal pump with a capacity of 187 kW from the refinery industry. The impeller wearing ring clearance problem has been investigated. This... 

The perpuse of this thesis is to design and fabricate a laboratory one degree of freedom stable platform under turbulences by model-based design method. To do this, different parts of the system were first modeled in the Solidworks software and then fabricated with various tools. With proper assembly of electronic and mechanical components, the original body of the system was created. Then, the controller motor with a stable platform which is attached to it was modeled and simulated in MATLAB software. Then, the parameters of the equations were calculated using standard identification tests and TCACS optimization algorithm. One of the challenges of this thesis is the malfunction of the... 

This study provides preliminary work on the development of manual rehabilitation device for wearable and robotic manual applications. This work examines the motion of the fingers using the sensors. The developed mechanism is based on a combination of strain gauge sensors and a stepper motor, which forms the motion of the artificial thumb. In this thesis, the creation of an artificial thumb has been done with one degree of freedom, the movement and grabbing of lightweight objects. For grabbing objects, the command of controlling and keeping objects is performed through the IAR software and labVIEW software which is given to the stepper motor.This study describes the details of the work done...