Sahaj Saxena
Indian Institute of Technology Roorkee
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Publication
Featured researches published by Sahaj Saxena.
IEEE Transactions on Power Systems | 2013
Sahaj Saxena; Yogesh V. Hote
The large-scale power systems are liable to performance deterioration due to the presence of sudden small load perturbations, parameter uncertainties, structural variations, etc. Due to this, modern control aspects are extremely important in load frequency control (LFC) design of power systems. In this paper, the LFC problem is illustrated as a typical disturbance rejection as well as large-scale system control problem. For this purpose, simple approach to LFC design for the power systems having parameter uncertainty and load disturbance is proposed. The approach is based on two-degree-of-freedom, internal model control (IMC) scheme, which unifies the concept of model-order reduction like Routh and Padé approximations, and modified IMC filter design, recently developed by Liu and Gao [24]. The beauty of this paper is that in place of taking the full-order system for internal-model of IMC, a lower-order, i.e., second-order reduced system model, has been considered. This scheme achieves improved closed-loop system performance to counteract load disturbances. The proposed approach is simulated in MATLAB environment for a single-area power system consisting of single generating unit with a non-reheated turbine to highlight the efficiency and efficacy in terms of robustness and optimality.
Iete Technical Review | 2012
Sahaj Saxena; Yogesh V. Hote
Abstract The current study endeavors to put together evolution, developments, and future prospects of internal model control strategy. Due efforts have been made to include all the techniques and philosophies used to that end. The brief account of the most recent techniques for near optimal and robust control has been provided along with a summary of conventional control schemes. At the same time, more emphasis is given on the issues in IMC design for single-input, single-output systems, like quantitative filter selection and tuning guidelines, modified structures, and related aspects of contemporary research developments. A set of references of all concerned papers, and a brief summary in them is provided. This paper also presents the results of these techniques as provided in the respective references. Illustrative example is given to show the effectiveness and the merits of the IMC based various forms.
IEEE Transactions on Power Systems | 2018
Sandeep D. Hanwate; Yogesh V. Hote; Sahaj Saxena
Till date, various load frequency control (LFC) schemes have been reported and every scheme has its own way of disturbance rejection capability. Utilizing some of them together may bring improved performance. Keeping this fact in mind, an adaptive control policy is proposed in this letter. The policy incorporates the concept of enhancing and lowering the controller activity by assigning them weights at every instance throughout the operation. Thus, there is no need to go for a new LFC scheme until required, and a guaranteed improved performance would be achieved. Different case studies including single and multi-area power systems have been conducted to verify the accuracy and efficiency of the proposed method.
international conference on industrial and information systems | 2015
Sahaj Saxena; Yogesh V. Hote; Swati Sondhi
In this paper, a method is proposed for stabilization of servo system using the fractional-order proportional-integral controller. The proposed scheme is based on the stability boundary locus concept for fractional-order control system. The design technique is simulated for speed control problem of the DC servomotor and implemented on the hardware set-up of precision modular servo system. The proposed controller gives desired set-point tracking with optimal performance under various load conditions.
indian control conference | 2016
Sahaj Saxena; Yogesh V. Hote
In this paper, an internal model control (IMC) based proportional integral (PI) controller is designed for DC servomotor using the concept of model order reduction. The beauty of the presented approach is that the optimal performance can be achieved by lower-order controller, hence reduces the size of the controller. Moreover, there is no need for extra filter which is generally augmented with IMC-PID controller. Particularly here, it is shown that without using additional filter, the performance of IMC-PI controller is better in comparison to IMC-PID controller with additional filter. The proposed methodology has been validated on an experimental set up of precision modular servo (PMS) system using its different reduced-order models. Further, it is shown that the reduced model based on Routh array is the best suited for obtaining optimal performance for speed control of PMS system.
international conference on control, automation, robotics and vision | 2016
Sahaj Saxena; V. Yogesh; Pushkar Prakash Arya
This paper proposes a new method of finding reduced-order model of a commensurate fractional-order (FO) system. The FO system is first converted to integer-order (IO) and then a mixed method of model-order reduction (MOR) scheme is applied. In this scheme, the denominator is obtained using time-moment matching method and the numerator is determined using the recently developed big bang-big crunch (BB-BC) optimization algorithm. This formulated reduced-order model is reconverted into its commensurate form of FO model. Three examples are presented to validate and illustrate the efficacy of the proposed approach.
international conference on industrial and information systems | 2015
Yogesh V. Hote; Sahaj Saxena; Amar Nath Jha
Model order reduction (MOR) is an important phenomenon in control theory for identification of higher-order model to a lower-order. However, it is observed that the practical application of MOR in designing a controller for obtaining desired performance is limited. Therefore, in this paper, we propose a two step approach of designing proportional-integral (PI) type controller in which the system to be controlled is approximated to a reduced model via Gerschgorin theroem and singular perturbation technique, and then the obtained model is employed to evaluate the tuning parameters of PI. The tuning is based on analytical approach of designers specification. The validation of proposed technique is carried out for speed control problem of DC servomotor through MATLAB simulations and hardware implementation on precision modular servo set-up. The analysis shows improved performance in terms of fast reference tracking and disturbance attenuation.
2015 International Conference on Computer and Computational Sciences (ICCCS) | 2015
Sahaj Saxena; Palak Anmol; Yogesh V. Hote
In this paper, a Graphical User Interface (GUI) is developed in MATLAB environment for educational and research purpose in the field of control engineering. This interactive user-friendly software focuses on the behavior and performance analysis of linear time invariant control system in time as well as frequency domain. The user can input the dynamics of the system in the form of transfer function or state-space format in GUI. Further, there is a facility of dropdown list where the user can get information about poles and zeros, transient response analysis for step and impulse input, Bode, Nyquist and Nichols diagrams. The report regarding controllability and observability of the system can also be generated using this toolbox. This toolbox has three sections, one for entering dynamics of system in state-space or transfer function form, second for selecting the different performance parameters to be analyzed and last the output panel for figures and reports. Moreover, the user can simultaneously compare performance of two systems.
ieee india conference | 2014
Anoop Cherian Thomas; Yogesh V. Hote; Sahaj Saxena
Water level control in boilers is an age old control problem that has challenged the frontiers of control engineering. More so the control problem offered by a marine boiler is even more intriguing. In this paper, a comparative study of cascade fuzzy logic controller for boiler water level control has been carried out between its different configurations. Thereafter a comparative study has been made to evaluate the merits of each controller. To evaluate performance of each controller, various performance parameters such as maximum overshoot, undershoot and settling time have been determined through MATLAB. After the comparative analysis of the controllers, it was concluded that the Interval Type-2 fuzzy logic cascade controller (IT2FLC) fares better than the Type-1 fuzzy logic cascade controller (T1FLC) and Mixed cascade controller.
2015 International Conference on Power and Advanced Control Engineering (ICPACE) | 2015
Shivanagouda Biradar; Sahaj Saxena; Yogesh V. Hote
Automatic voltage regulator (AVR) is an essential entity for power system operation. Therefore, to observe the behavior and performance of AVR, study of its modeling is necessary. Since AVR is a complex system having higher order transfer function, so it is tedious to study it. In this paper, different model reduction scheme have been discussed and implemented for this system. We have applied ten different model order reduction schemes and a descriptive study of time and frequency domain analysis has been carried out. It has been observed that although different reduced models emulate the original system but their characteristics in frequency domain vary when few specifications are taken into account, for example, gain and phase margins, notch characteristics, etc. Therefore, on the basis of requirements, system engineer has to select particular reduced model for analysis and controller synthesis.