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Öğe Hysteresis Current Control of Buck-Boost Non-Isolated Onboard Charger for Electric Vehicles(IEEE Computer Society, 2023) Komurcugil, H.; Guler, N.; Bayhan, S.; Gulbudak, O.This paper proposes a hysteresis current control (HCC) method for a single-inductor buck-boost non-isolated onboard charger for electric vehicles. The charger is capable of working both in the boost and buck modes. The proposed HCC relies on the buck-boost inductor current and its reference which is generated using a proportional-resonant (PR) controller using grid current error. The reference current generated by PR controller is modified to suppress the oscillations in the inductor currents. An active damping by using a virtual resistor connected in series to filter inductor is used which does not require an additional sensor. A proportional-integral (PI) controller is used to generate the amplitude of grid current reference, which is utilized in constant current (CC) and constant voltage (CV) modes. The effectiveness of the proposed control strategy as well as the control method, is investigated by simulation studies by considering two different battery voltage levels (48V and 350V). The results show that the proposed method is able to charge the battery in CV and CC modes. Moreover, the grid current is maintained in unity power factor at a reasonably low total harmonic distortion (THD) which is smaller than the limits recognized by international standards. © 2023 IEEE.Öğe The Impact of SMES Integration on the Power Grid: Current Topologies and Nonlinear Control Strategies(Springer Science and Business Media Deutschland GmbH, 2024) Khaleel, M.; Gulbudak, O.; Ayed, S.K.; Mustafa, M.A.S.; Majdi, H.S.; Habeeb, L.J.; Elmnifi, M.Superconducting magnetic energy Storage (SMES) has recently provided fast and effective relief on the power grid (PG). In addition to that, the power quality (PQ) issues affecting the PG continue to receive special attention. There is no doubt that the PQ issues are an important point concerning the effect on the power grid (PG) utility. In this context, this manuscript aims to demonstrate in-depth the configurations, characterization, and properties of SMES as a robust energy storage (ES) technology. The main objective of SMES can be achieved by delivering excellent performance to support the demand load. From this perspective, current topologies SMES-PG interconnection are developed to evaluate the effectiveness and performance-enhancing while supplying efficient energy using non-linear control strategy including sliding mode controller strategies, partial feedback linearization, control strategy, hysteresis controller strategy, robust controller strategy, and predictive controller strategy. To conclude, this manuscript investigates in detail to determine the applications of SMES-PG interconnection and future scope. © The Author(s), under exclusive license to Springer Nature Switzerland AG 2024.Öğe Model Predictive Control for Battery Charger Applications with Active Damping(Institute of Electrical and Electronics Engineers Inc., 2019) Gokdag, M.; Gulbudak, O.This paper presents a model predictive control approach for a current source rectifier that can be used as battery charger fed from three-phase ac grid. The proposed MPC technique allows to charge the battery with a constant current or voltage as what is required for cyclic charge process of batteries. The proposed technique ensures unity input power factor operation for grid side. Instantaneous active and reactive power control combined with active damping technique is achieved to obtain safe charging process. The method does not require any input current sector information, and there is no need for sinusoidal input current reference synchronized with grid voltage. The proposed control method requires only active power demand to control whole system. A simulation study is carried out to observe the proposed method in terms of steady-state and dynamic responses and supply current quality. © 2019 IEEE.Öğe Model Predictive Control of Two Separate Induction Machines using Dual-Output Indirect Matrix Converter(Institute of Electrical and Electronics Engineers Inc., 2019) Gulbudak, O.; Gokdag, M.Predictive torque and flux control methods for two separate induction machines fed by dual-output indirect matrix converter is presented in this paper. Mathematical models of induction machine and power stage are used to predict future behavior of control objectives and best switching combination is selected by evaluating multi-objective cost function. Basically, torque and flux errors are considered in a user defined cost function and proposed control approach aims to minimize these errors. The method is validated through simulation results where it is shown that dual-output indirect matrix converter combined with predictive control approach can control two induction machines independently. © 2019 IEEE.Öğe Model Predictive Sliding Surface Control of Induction Motor fed by Direct Matrix Converter(Institute of Electrical and Electronics Engineers Inc., 2022) Gulbudak, O.; Gokdag, M.; Komurcugil, H.This paper presents a novel induction motor control strategy for a direct matrix converter. The proposed method consists of two cascaded-control blocks: the stator current control block and the supply current control block. The stator current control block uses the sliding mode control stability term to formulate the objective function. The composed objective function includes the stability expression to regulate the motor speed, torque, and stator current. The second control block contains the predictive active damping method to improve supply current quality. In grid-connected converters, the supply current may suffer from distorted harmonics. To overcome this problem, a damping current is injected into the reference signal. The proposed method offers a reliable motor operation and system performance under steady-state and transient conditions. The simulation works verify the mathematical concept. The simulation results demonstrate that the proposed control method can regulate the motor dynamics while drawing the sinusoidal supply current. © 2022 IEEEÖğe Model Predictive Sliding Surface Control of Voltage Source Inverter(Institute of Electrical and Electronics Engineers Inc., 2022) Gulbudak, O.; Gokdag, M.; Komurcugil, H.This paper presents the model predictive sliding surface control strategy to control the voltage source inverter. The proposed control method benefits from the sliding mode control stability rule to shape the objective function of the optimization problem. The objective function is tailored such that the asymptotic stability criterion is used during the exploration of the optimum control input. The conventional model predictive control method is an effective control routine to handle multiple control goals. However, it can cause closed-loop instability in case of poor selection of the weighting factors or cost function. Due to this unfavorable characteristic of the conventional model predictive control method, the sliding mode control stability criterion is used as a control objective. The proposed objective function formulation guarantees the closed-loop stability regardless of the converter operation points such as power level. The proposed method does not require the weighting factors, which are usually necessary for the applications where the objective function is formed by two or more control goals, thus the system stability is improved. The proposed method is validated by the simulation works, and the results prove the effectiveness of the proposed control method. © 2022 IEEEÖğe Pipelining Strategies and Design Considerations of Predictive Current Control Method(TUBITAK, 2022) Gulbudak, O.; Gokdag, M.This paper explores the pipelining strategies for the model predictive control methods. The array and vector processing methods are examined to discover their applicability in the model predictive current method. The potential benefits of the pipelining methods are investigated, and their design methodologies are scrutinized. The model predictive control is a nonlinear control technique that predicts the system dynamics. The model predictive control (MPC) provides rapid response to the load variations and guarantees robust operation. However, the lower sampling period is the main design constraint to achieve a reliable system operation. The selection of a low sampling period demands a powerful digital controller due to the increasing computational burden. To handle the high calculation burden, a field-programmable gate array (FPGA) is a powerful solution. A proper pipelining strategy enables the use of the MPC in real-time applications. In this paper, pipelining strategies and practical design considerations of the FPGA-based predictive current method are presented. The nine switch converter (NSC) is selected as an experimental case study. The experimental results are provided to demonstrate the theoretical framework. The experimental results prove the feasibility of the array processing and vector processing methods in MPC applications. © 2022, TUBITAK. All rights reserved.Öğe Predictive Current Control Method with State Observer for Grid-Connected Inverter Equipped with LCL-Filter(Institute of Electrical and Electronics Engineers Inc., 2021) Gulbudak, O.; Gokdag, M.This paper presents a predictive control strategy for a grid-connected voltage source inverter with an LCL filter. A full-state observer is used to estimate the LCL filter capacitor voltage to reduce the sensing component. The estimated capacitor voltage is used by the proposed predictive control method. The LCL filter model and converter model are used to predict the control goals. The objective function without the weighting factor is formulated to form the optimal control problem. The proposed control strategy offers an excellent steady-state and transient performance. Design steps for the state estimator and the proposed method are extensively provided. The simulation work validates the theoretical framework. The simulation results confirm that the proposed control method provides a stable grid integration and robust energy conversion process. The theoretical expectations are verified by the simulation-based case studies. © 2021 IEEE.Öğe Sliding Mode Current Control Strategy for Nine-Switch Converter(Institute of Electrical and Electronics Engineers Inc., 2021) Gulbudak, O.; Gokdag, M.; Komurcugil, H.This paper proposes a sliding mode control strategy for regulating dual-load fed by a nine-switch converter. The nine-switch converter consists of two three-phase output terminals, and the nine-switch converter can control dual-loads. The nine-switch converter contains fewer switching devices compared to the two-parallel voltage-source inverters. The nines witch converter offers a more compact ac-drive system where multiple load control is required regarding power stage weight and size. Nevertheless, attaining a fully independent control for individual load is a challenging task. The poor closed-loop design causes an unpleasant circulating current between separate load stages. Therefore, the possibility of the interaction between different load stages is the primary closed-loop design consideration. This study proposes the sliding mode control to obtain a reliable energy conversion operation method for a dual output nine-switch converter. Sliding mode control methodology is comprehensively explained, and solid design steps are provided. The simulation work verifies the theoretical framework of the designed sliding mode controller. The performed simulation works demonstrate that multiple ac loads are well regulated by the proposed control method. © 2021 IEEE.
