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ThesisItem Open Access Performance Analysis of Line Start Permanent Magnet Synchronous Motor using Finite Element Method(2022-10) Dwivedi, Harsh; Rawat, Harendra SighThe transportation sector accounts for 23% of greenhouse gas (GHG) emissions worldwide through vehicle fuel combustion. Meeting climate mitigation goals requires transformative changes in the transport sector. This includes transition from current fuel combusting vehicles to Electric Vehicles (EVs). EVs have the potential to have significant effects on energy, the environment, and transportation. Qualities like higher power density, smaller size and higher efficiency make PMSM a superior candidate than its counterparts. Therefore, the performance of Permanent Magnet Synchronous Motor (PMSM) is analysed in this thesis using Finite Element Method. A buried magnet type Line Start PMSM motor is simulated using Ansys Maxwell Software. Finite Element Method for the transient analysis of simulated PMSM in Ansys Maxwell software gave us better understanding of flux pattern and magnetic field. Concept of Cogging Torque is also discussed. A 3-phase Sinusoidal Pulse Width Modulated (SPWM) Inverter is simulated in Ansys Simplorer Software and Dynamic Analysis of above simulated motor is examined. Speed control techniques are discussed and Field Oriented Control (FOC) is implemented using MATLAB Simulink Software. Performance analysis of PMSM’s speed, torque and current for sudden load changes is observed. The FOC speed controller is than tuned for low maximum peak overshoot and low settling time using hit and trial method to give better results. PMSMs are becoming more and more relevance with the advent of power electronics devices, use of stronger magnets, and better speed control techniques.ThesisItem Open Access Comparison of PI and Fuzzy Logic Controller for the Speed Control of Switched Reluctance Motor(G. B. Pant University of Agriculture & Technology, Pantnagar-263145, 2022-10) Gupta, Navneet Kumar; Gupta, ShobhitDue to its simple structure and its reliability Switched Reluctance Motor (SRM) is becoming very popular. Usually, typical PI controller is used to regulate the speed of SRM. In the thesis, a PI controller and Fuzzy Logic Controller (FLC) is designed to control the speed of SRM drive. The performance of SRM with PI and Fuzzy Logic controller is analyzed in Matlab/Simulink platform. To prove the superiority of FLC, its performance is compared with typical PI controller. Performance of the switched reluctance motor has simulated and studied with typical PI and Fuzzy Logic Controller. From the simulation results obtained, it showed that FLC can improves the speed response of SRM drive with less settling time, less rise time as compared to typical PI controller. Finally, it is proven that FLC is suitable for SRM drive to achieve the smooth speed response over a wide range of speeds. Hence from the analysis of switched reluctance motor with PI and FLC we can say that the speed control of Switched Reluctance Motor is better in case of Fuzzy Logic Controller as compared with PI controller.ThesisItem Open Access Performance Analysis of Squirrel Cage Induction Motor using Finite Element Method(G. B. Pant University of Agriculture & Technology, Pantnagar-263145, 2022-10) Rani, Sanyogita; Rawat, Harendra SighPresently, Induction motors are driving forces of industry for both controlled and uncontrolled applications because of their robust construction and easier controlling techniques with efficient energy conversion. In addition, Three-phase induction has a low price, a reasonably good power factor, self-starting, and a low cost of maintenance. Three-phase squirrel-cage induction motors are widely used as industrial drives due to their self-starting, reliability, and economy. In this thesis modeling and analysis of three-phase squirrel cage induction motor and simulation using ANSYS Electronics has been done. The finite element method provides us to compute induction motor characteristics. The motor parameters and characteristics can be precisely calculated and predicted in terms of field computation and analysis results. Magnetic flux lines, Magnetic flux density, and transient analysis using the Maxwell 2d model are analyzed and animated using the two-dimensional finite element method in ANSYS Maxwell 2D. A 3-phase Sinusoidal Pulse Width Modulated (SPWM) Inverter is simulated in Ansys Simplorer Software and the Dynamic Analysis of the above-simulated 2D transient model of induction motor is examined. MATLAB-SIMULINK is used for the analysis, of the close loop V/f control of the Induction Motor in MATLAB, using the PID controller. The PID based feedback controller functioning is validated by results of Matlab based simulation model. The variation of torque, and rotor speed for target reference speeds and sudden load changes is observed.ThesisItem Open Access A NOVEL CONTROL STRATEGY FOR PARALLEL CONNECTED INVERTERS IN AUTONOMOUS AC MICROGRID(G. B. Pant University of Agriculture & Technology, Pantnagar-263145, 2022-09) Bhatt, Neha; Arora, SudhaIn the past few years, a conventional centralized grid structure has been shifting towards a decentralized structure due to the availability of renewable energy-based Distributed Generation (DG) units. But the management of these DG sources in the distribution network is not an easy task due to the problems associated with the operation and control. The control structure should be able to provide coordinated control with all parallel connected DG units and achieve stable operation of the whole network. Especially during autonomous mode, the control structure has to maintain and regulate the voltage and frequency of the whole network and has to decide power sharing between parallel connected DG units. The droop-based control schemes measure locally available parameters and process them to generate control signals. Based on load demand, droops are introduced in operating voltage and frequency and operating set points are decided. Each DG unit regulates its control parameter at local level. The advantage of this control is that by establishing stability of a single unit at local level we can expect stability of the whole system at global level. The concept of droop control for converter-based DG sources was derived from the inherent property of the governor of synchronous generators. These synchronous generators supply power to the load through transmission lines and the whole network is highly inductive in nature. But DG based network is resistive in nature and due to the presence of power electronic interface (e.g. converters etc.), these have low or no inertia. The implementation of conventional droop controller in such a network leads to poor network performance and slow response. High transients may occur in the system during disturbances which might be high enough to damage or may cause mal-operation of equipments and might make whole network unstable. To address drawbacks associated with conventional droop control technique, this thesis presents a modified control scheme. The drawback associated with conventional droop control strategy are identified through intensive analysis in MATLAB/Simulink environment and an improved control strategy is proposed. Performance is analyzed under varying loading conditions and integrating DG sources at different time instants. Simulation results show that proposed control strategy is capable of regulating voltage and frequency of the network according to the load demand. It improves transient response of the system and provides a faster and more damped response to maintain stable operation of the network.ThesisItem Open Access Improvement of voltage profile in distribution system using compensating devices(G. B. Pant University of Agriculture and Technology, Pantnagar, 2022-10) Pandey, Kamal; Singh, SunilOptimal reactive power deployment in accordance with the statutory provisions of Indian Electricity Grid Codes is important for better performance of the system. Better voltage profile, lower losses, and improved efficiency are measures of distribution system quality. The aim is to keep the system operating smoothly with a better voltage profile at every node. A good distribution network is hence expected to improve overall efficiency of the system through loss minimization and power quality control. Due to the bidirectional nature of the present distribution system, DFACTS devices are gaining relevance almost everywhere for quick voltage management, power quality maintenance, and enhanced stability margins In this research work, a 33 bus distribution system of base 12.66 kV and 10 MVA is taken into consideration. After that, the improvement of voltage profile is discussed. By using load flow analysis, the values of unknown parameters are calculated. The impact of single and multiple D-STATCOM is investigated. The minimum voltage profile is improved to 0.9523 pu (5.18 % from base case) and 0.9780 pu (8.18 % from base case) from 0.9040 pu in single and multiple D-STATCOM cases respectively. The real and reactive power losses are reduced by 28.37 % and 27.55 % in single D-STATCOM case; while in the case of multiple D-STATCOM case, this reduction is 38.09 % and 37.02 % respectively. Overall, it is concluded that in this case, the D-STATCOM helps in improving the voltage profile by injecting a suitable amount of reactive power into the system.ThesisItem Open Access Analysis of the performance of different induction motors under various voltage sag conditions(G. B. Pant University of Agriculture and Technology, Pantnagar, 2022-10) Sati, Karan; Gupta, ShobhitVoltage sag is one of the primary concerns in power quality disturbance, even though there are several ways to characterize voltage sag, two basic characteristics i.e. sag magnitude and sag duration are the two most commonly used. Electromagnetic torque generated by an induction motor is directly proportional to the square of the voltage. Due to the wide use and popularity of induction motors, this thesis investigates the effect of voltage sag duration, loading conditions, and power rating on the performance of induction motors under different voltage sags at various points of sag initiation. In the MATLAB Simulink environment, simulations of two different rated induction motors under various voltage types of sags of magnitudes (0.2 pu,0.5 pu, and 0.8 pu) and duration 10 cycles (instantaneous sag) or sag of duration 1 sec (momentary sag) are performed. Results of the simulations have been compared based on torque peaks and current peaks. It has been found that the torque peak for an instantaneous sag is similar to the torque peak for a momentary sag for each type of voltage sags. Whereas current peaks were affected by the sag duration it has been found for momentary voltage sag of Type A, Type C, and Type D the magnitude of the current peak increases in comparison to instantaneous voltage sag. The effects of loading conditions and power rating are also investigated.ThesisItem Open Access Design and analysis of three phase active series compensator for power quality improvement in distribution system(G. B. Pant University of Agriculture and Technology, Pantnagar, 2022-08) Kousar Jan; Kousar Jan; Kousar Jan; Pathak, Geeta; Pathak, Geeta; Pathak, GeetaPower quality is one of the main issues in today's electrical distribution system because of the escalation in use of power electronic devices. Harmonics, voltage sag, voltage swell, power interruptions, and other problems with power quality have an impact on utility distribution networks and sensitive industrial loads. In this thesis, a three-phase DVR (Dynamic Voltage Restorer) model is developed in Matlab-Simulink to protect critical loads from voltage-related power quality problems. The detailed design of the primary system parameters, including the voltage source converter (VSC), the three-phase series injection transformer, the ripple filter (Rr, Cr), and the interfacing inductance (LT) is provided. The simulation of Synchronous Reference Frame Theory (SRFT), Instantaneous Reactive Power Theory (IRPT), Affine Projection (AP), and Affine Projection Like (APL-II) algorithm based three-phase DVR is performed and analysed under a number of source side voltage quality issues, including balanced voltage sag and swell, unbalanced voltage sag and swell, and voltage harmonic distortion. The voltage harmonic distortion is analysed for both lower and higher order harmonics. PI (Proportional Integral) controller is used to keep the DC-link voltage constant. The SPWM (Sinusoidal Pulse Width Modulation) technique is used to generate gate pulses for the VSC (Voltage Source Converter) of DVR. The comparison of stability, time response, convergence speed, and THD (Total Harmonic Distortion) for both lower and higher order harmonics is done thoroughly. These control algorithms use energy-minimized voltage compensation technique which makes the Dynamic Voltage Restorer self-supporting in nature i.e. only the capacitor is adequate at the DC-bus of the VSC, and no additional energy storage device is required.ThesisItem Open Access Modelling Li-ion batteries with distinct chemistries using advanced system identification based data driven techniques(G.B. Pant University of Agriculture and Technology, Pantnagar, District Udham Singh Nagar, Uttarakhand. PIN - 263145, 2022-08) Rawat, Shivani; Singh, RajivRecently Li-ion batteries have emerged as a potential candidate for reliable energy storage. This had been on the account of their high energy density and power as compared to their counterparts in addition to long life and improved charge-discharge cycles. Li-ion batteries are available in chemistries such as NCA, NMC, LFP, LCO, etc. Li-ion batteries being critical to EVs and other applications involving energy storage requirements need to be modelled accurately and precisely. This is essential for proper energy management by calculating the SOC, SOH, and RUL of the battery. Accurate models are necessary to be incorporated within the BMS handling the optimal regulation of the energy output from battery including the efficient charging. In this thesis work three different chemistries of Li-ion battery have been chosen for modelling using advanced data driven method called system identification. The selected chemistries of Li-ion batteries are NCA, NMC, and LFP. For each chemistry a linear Transfer function model and a nonlinear model Hamm- Wiener model has been realized using system identification approach also sometimes called experimental based modeling technique. A set of linear and nonlinear models are created using system identification technique. The mathematical metrics of the fit between the reference and simulated signals is used to choose the optimal and best model. In comparison to the linear model the nonlinear model was obtained to be more accurate for all the batteries. The accuracies achieved by the nonlinear model for NCA, NMC, and LFP are 94.15%, 92.23%, and 90.78% respectively. Hence, it can be concluded that the Hammwiener model being the best can be used effectively for representing a Li-ion battery in different applications using BMS.ThesisItem Open Access Evaluation and comparison of active cell balancing methods using energy storing elements(G.B. Pant University of Agriculture and Technology, Pantnagar, District Udham Singh Nagar, Uttarakhand. PIN - 263145, 2022-09) Panwar, Garima; Saxena, RaviIn recent years the popularity of using lithium-ion batteries for energy storage purposes has risen a lot. However, the range of lithium-ion batteries available in the market is very small and for higher power requirements a significant number of cells are to be connected in series and parallel combinations. But when the cells are connected in series the problem of imbalance arises among them. Over the time, imbalance causes cell deterioration and reduced efficiency, therefore cell balancing becomes necessary in order to make sure the safe and reliable operation of lithium-ion batteries. The functionality of cell balancing is integrated within a Battery Management System. Cell balancing can be done in two ways i.e., passive balancing and active balancing. In passive balancing the excess charge is dissipated through a resistive element until all the cells come in balance with each other and in active balancing the excess charge is redistributed from higher energy cell to lower energy cell by using an external energy storing element such as an inductor, capacitor etc. In this work, capacitor-based active cell balancing has been studied because they have a simpler controlling mechanism as well as their implementation costs are less. More specifically, in this work, the implementation and comparison of switched capacitor, double-tiered switched capacitor, and chain-structure switched capacitor based balancing techniques have been done. The modelling of these techniques has been done in MATLAB/ Simulink and results are obtained for a series combination of 4 number of lithium-ion cells having 3.7V and 2.6A ratings with initial SOC variation as 15% and 8%. The cells are considered to be balanced when the maximum SOC difference between them reaches 1%. The results show that the double-tiered balancing technique takes the least time to balance the cells as compared to the switched capacitor and double chain-structure based techniques.
