Subhash Chander Dubey
@gcetjammu.org.in
Associate Professor , Department of Electronics & Communication
Govt.College of Engineering and Technology, Jammu
RESEARCH INTERESTS
Micro Electronics, Low Power VLSI design, FPGA based digital design, Digital Controller design, FPGA based Controller Design, FPGA Based DPWM Design, DC-DC Converters for Low Voltage Applications, Topologies and their Control
Scopus Publications
Scopus Publications
Subhash Chander, Pramod Agarwal, and Indra Gupta
Walter de Gruyter GmbH
AbstractPulse width modulation (PWM) has been widely used in power converter control. This paper presents a review of architectures of the Digital Pulse Width Modulators (DPWM) targeting digital control of switching DC-DC converters. An attempt is made to review the reported architectures with emphasis on the ASIC and FPGA implementations in single phase and single-output DC-DC converters. Recent architectures using FPGA’s advanced resources for achieving the resolution higher than classical methods have also been discussed. The merits and demerits of different architectures, and their relative comparative performance, are also presented. The Authors intention is to uncover the groundwork and the related references through this review for the benefit of readers and researchers targeting different DPWM architectures for the DC-DC converters.
Subhash Chander, Pramod Agarwal, and Indra Gupta
American Scientific Publishers
Subhash Chander, Pramod Agarwal, and Indra Gupta
IEEE
Ziegler-Nichols tuned PID controller's performances usually are not acceptable for applications requiring precise control. In this paper an improved discrete auto-tuning PID scheme is developed for DC-DC converters where large load changes are expected or the need for fast response time. The algorithm developed in this paper is used for the tuning discrete PID controller to obtain its parameters with a minimum computing complexity and is applied to Synchronous buck converter to improve its performance. To improve the transient response and rise time of the Converter, the controller parameters are continuously modified based on the current process trend. For its implementation a synchronous buck converter is designed and its MATLAB/Simulink model with non-linear parameters is developed and considered. Also, the non-linear effects such as S/H, quantization, delay, and saturation are considered in the close loop model. The simulation results demonstrate the effectiveness of the developed algorithms.
Subhash Chander, Pra mod Agarwal, and Indra Gupta
IEEE
Proportional Integral Derivative (PID) controller is the most preferable controller in industries that does not require precise analytical model of the system to be controlled. This paper presents a design and implementation of PID (Proportional-Integral-Derivative) controller based on FPGA (Field-Programmable Gate Arrays) for low voltage synchronous buck Converter. Matlab/Simulink environment is used for the PID controller design to generate a set of coefficients associated with the desired controller characteristics. These controller coefficients are then included in VHDL that implements the PID controller on to FPGA. The two architectures of PID controller are considered with their device utilization and power dissipation reports to show the resource utilization and power dissipation of selected FPGA. The architectures are implemented in FPGA Virtex-5(ML505) XC5VLX50T-1FF1136 (-1 speed grade) device.
Subhash Chander, Pramod Agarwal, and Indra Gupta
IEEE
Modeling and simulation generally form an integral part of design process. The simulation tools are increasingly important in the development of new system and their optimum design. This paper presents design and simple method of modeling DC-DC converter using MATLAB/Simulink. The nonlinear parameters such as equivalent series resistance of the inductor and capacitor and the threshold voltage of MOSFET switches are considered in the model. Similarly, the non-linear effects such as S/H, quantization, delay, and saturation are considered in the closed loop controller design and simulation. The simulation results are given to support the design validation.
Subhash Chander, Pramod Agarwal, and Indra Gupta
IEEE
This paper presents design, modeling and simulation of a low-power digitally controlled synchronous rectifier (SR) buck converter. Due importance is given in the model to the effect of non-linear parameters in low voltage converters, such as equivalent series resistance ESL of the inductor, ESR of capacitor and RDS(on) of MOSFET switches. A digital PID controller is design adopting direct digital design approach, further to improve its transient response the design is modified to achieve Auto-tuned discrete PID Controller (AT-PID).The performances of two controllers are compared. Simulations of a digital control synchronous buck are performed with Matlab/Simulink. The simulation results show that the approach enables high-speed dynamic performance.