scholarly journals DIGITAL CONTROL OF A CLOSED LOOP BUCK CONVERTER

2021 ◽  
Vol 5 (10) ◽  
Author(s):  
Doshi Prarthana
Keyword(s):  
Digital Control ◽  
Buck Converter ◽  
Control Technique ◽  
Digital Controllers ◽  
Switch Mode Power Supply ◽  
Performance Specification ◽  
Analog Control ◽  
Response Voltage ◽  
Advanced Control ◽  
Primary Focus

The primary focus for the R&D in this area so far has been to figure out the best approach for evaluating and designing the DC-DC converter and perhaps the most appropriate control technique is being applied in different DC-DC converter circuits. Depending on power handling capacity as well as high-frequency switching, certain switching devices are chosen. This paper discusses the deployment of the digital PID controllers in the DC-DC converters. In an attempt to get a quicker response, voltage mode control has been used. Digital controllers started replacing traditional analog controllers more and more. Better immunity to changes in the environment which includes temperature and degradation of components, improved versatility by modifying the software, increasing advanced control methods, and decreased number of the components are the key benefits of the digital control against the analog control. A structured and concise strategy for designing a digitally operated close-loop Dc / Dc buck converter is discussed in this paper beginning with the Buck converter and giving the set of certain performance specification, implementations of the digital Proportional-IntegralDerivative(PID) controller is made. It addresses in depth all the appropriate DSP hardware and/or software methods and approaches needed to implement a controller. In order to illustrate the efficacy of the model, the dynamic response as well as the steady-state performance of controller is provided. The experimental outcomes fit well with the model of simulation. During the implementations of Switch Mode Power Supply (SMPS), application of dsPIC provides new perspectives towards affordable and versatile approaches of digital control.

A comparative study of phase margin based digital and analog controlled synchronous buck with optimum LC filter

2019 ◽  
Vol 38 (6) ◽  
pp. 2020-2039
Author(s):  
Ruchi Rashmi ◽  
Shweta Jagtap
Keyword(s):  
Discrete Time ◽  
Digital Control ◽  
Buck Converter ◽  
Pi Control ◽  
Phase Margin ◽  
Control Loop ◽  
Digital Controllers ◽  
Pass Filter ◽  
Content Type ◽  
Analog Control

Purpose Traditionally, industrial power supplies have been exclusively controlled through analog control to sustain high reliability with low cost. However, with the perpetual decrement in cost of digital controllers, the feasibility of a digitally controlled switch mode power supply has elevated significantly. This paper aims to outline the challenges related to the design of digital proportional-integral (PI) controlled synchronous rectifier (SR) buck converter by comparing controller performance in continuous and discrete time. The trapezoidal approximation-based digital PI control is designed for low voltage and high-frequency SR buck converter operating under continuous conduction mode. Design/methodology/approach The analog and digital controller are designed using a SISO tool of MATLAB. Here, zero-order hold transform is used to convert the transfer function from continuous to discrete time. Frequency and time domain analysis of continuous plant, discrete plant and close loop system is performed. The designed digital PI control is simulated in MATLAB Simulink. The simulated results is also verified on hardware designed around digital signal processing control. Findings The continuous and discrete control loops are validated with multiple tests in the time and frequency domain. The detailed steady state theoretical analysis and performance of the SR buck converter is presented and verified by simulation. It is found that the delay in digital control loop results in a low phase margin. This phase margin decreases with higher bandwidth. The hardware experiments with the digital control loop are carried out on a 10 W prototype. The chosen parameters for the SR buck converter are found to be optimum for steady and transient state response. Originality/value This paper compares the digital and analog control approach of compensator design. It focuses on the implications created at the time of transforming the control design from continuous to discrete time. Further, it also focuses on the selection of parameters such as phase margin, bandwidth and low pass filter.

scholarly journals Challenges and implementation aspects of switched-mode power supplies with digital control for automotive applications

2016 ◽  
Vol 14 ◽  
pp. 85-90 ◽  
Author(s):  
Samuel Quenzer-Hohmuth ◽  
Thoralf Rosahl ◽  
Steffen Ritzmann ◽  
Bernhard Wicht
Keyword(s):  
Digital Control ◽  
Buck Converter ◽  
Power Supplies ◽  
Analog To Digital Converter ◽  
Digital Converter ◽  
Control Loop ◽  
Analog To Digital ◽  
Analog Control ◽  
Parameter Variations ◽  
Switched Mode Power Supplies

Abstract. Switched-mode power supplies (SMPS) convert an input DC-voltage into a higher or lower output voltage. In automotive, analog control is mostly used in order to keep the required output voltages constant and resistant to disturbances. The design of robust analog control for SMPS faces parameter variations of integrated and external passive components. Using digital control, parameter variations can be eliminated and the required area for the integrated circuit can be reduced at the same time. Digital control design bears challenges like the prevention of limit cycle oscillations and controller-wind-up. This paper reviews how to prevent these effects. Digital control loops introduce new sources for dead times in the control loop, for example the latency of the analog-to-digital-converter (ADC). Dead times have negative influence on the stability of the control loop, because they lead to phase delays. Consequently, low latency is one of the key requirements for analog-to-digital-converters in digitally controlled SMPS. Exploiting the example of a 500 kHz-buck converter with a crossover frequency of 70 kHz, this paper shows that the 5 µs-latency of a ΔΣ-analog-to-digital-converter leads to a reduction in phase margin of 126°. The latency is less critical for boost converters because of their inherent lower crossover frequencies. Finally, the paper shows a comparison between analog and digital control of SMPS with regard to chip area and test costs.

Digital control of multiphase Series Capacitor Buck converter prototype for the powering of HL-LHC Inner Triplet magnets

2021 ◽  
pp. 1-1
Author(s):  
Edorta Ibarra ◽  
Antoni Arias ◽  
Inigo Martinez de Alegria ◽  
A. Otero-Olavarrieta ◽  
Louis De Mallac
Keyword(s):  
Digital Control ◽  
Buck Converter ◽  
Series Capacitor

Application of Digital Control Techniques for Satellite Medium Power DC-DC Converters

2011 ◽  
Vol 57 (1) ◽  
pp. 77-83 ◽  
Author(s):  
Konrad Skup ◽  
Paweł Grudziński ◽  
Piotr Orleański
Keyword(s):  
Digital Control ◽  
High Speed ◽  
Control Process ◽  
Digital Signal ◽  
Current Mode ◽  
Power Converter ◽  
Buck Converter ◽  
Research Centre ◽  
Analog To Digital ◽  
Control Techniques

Application of Digital Control Techniques for Satellite Medium Power DC-DC Converters The objective of this paper is to present a work concerning a digital control loop system for satellite medium power DC-DC converters that is done in Space Research Centre. The whole control process of a described power converter is based on a high speed digital signal processing. The paper presents a development of a FPGA digital controller for voltage and current mode stabilization that was implemented using VHDL. The described controllers are based on a classical digital PID controller. The converter used for testing is a 200 kHz, 750W buck converter with 50V/15A output. A high resolution digital PWM approach is presented. Additionally a simple and effective solution of filtering of an analog-to-digital converter output is presented.

scholarly journals Optimized Digital Controllers for Switching-Mode DC-DC Step-Down Converter

Electronics ◽  
2018 ◽  
Vol 7 (12) ◽  
pp. 412 ◽  
Author(s):  
Ghulam Abbas ◽  
Jason Gu ◽  
Umar Farooq ◽  
Muhammad Abid ◽  
Ali Raza ◽  
...  
Keyword(s):  
Least Squares ◽  
Dynamic Performance ◽  
Nonlinear Least Squares ◽  
Optimization Method ◽  
Buck Converter ◽  
Digital Controllers ◽  
Real Zeros ◽  
Power Stage ◽  
Step Down ◽  
Zeros And Poles

In this paper, a nonlinear least squares optimization method is employed to optimize the performance of pole-zero-cancellation (PZC)-based digital controllers applied to a switching converter. An extensively used step-down converter operating at 1000 kHz is considered as a plant. In the PZC technique, the adverse effect of the (unwanted) poles of the buck converter power stage is diminished by the complex or real zeros of the compensator. Various combinations of the placement of the compensator zeros and poles can be considered. The compensator zeros and poles are nominally/roughly placed while attempting to cancel the converter poles. Although PZC techniques exhibit satisfactory performance to some extent, there is still room for improvement of the controller performance by readjusting its poles and zeros. The (nominal) digital controller coefficients thus obtained through PZC techniques are retuned intelligently through a nonlinear least squares (NLS) method using the Levenberg-Marquardt (LM) algorithm to ameliorate the static and dynamic performance while minimizing the sum of squares of the error in a quicker way. Effects of nonlinear components such as delay, ADC/DAC quantization error, and so forth contained in the digital control loop on performance and loop stability are also investigated. In order to validate the effectiveness of the optimized PZC techniques and show their supremacy over the traditional PZC techniques and the ones optimized by genetic algorithms (GAs), simulation results based on a MATLAB/Simulink environment are provided. For experimental validation, rapid hardware-in-the-loop (HiL) implementation of the compensated buck converter system is also performed.

scholarly journals Assessment of an Average Controller for a DC/DC Converter via Either a PWM or a Sigma-Delta-Modulator

2014 ◽  
Vol 2014 ◽  
pp. 1-17 ◽  
Author(s):  
R. Silva-Ortigoza ◽  
F. Carrizosa-Corral ◽  
J. J. Gálvez-Gamboa ◽  
M. Marcelino-Aranda ◽  
D. Muñoz-Carrillo ◽  
...  
Keyword(s):  
Power Electronics ◽  
Trajectory Tracking ◽  
Sliding Mode ◽  
Buck Converter ◽  
Control Technique ◽  
Sigma Delta Modulator ◽  
Control Laws ◽  
Sigma Delta ◽  
Variable Structure Systems ◽  
Average Control

Sliding mode control is a discontinuous control technique that is, by its nature, appropriate for controlling variable structure systems, such as the switch regulated systems employed in power electronics. However, when designing control laws based on the average models of these systems a modulator is necessary for their experimental implementation. Among the most widely used modulators in power electronics are the pulse width modulation (PWM) and, more recently, the sigma-delta-modulator (Σ-Δ-modulator). Based on the importance of achieving an appropriate implementation of average control laws and the relevance of the trajectory tracking task in DC/DC power converters, for the first time, this research presents the assessment of the experimental results obtained when one of these controllers is implemented through either a PWM or aΣ-Δ-modulator to perform such a task. A comparative assessment based on the integral square error (ISE) index shows that, at frequencies with similar efficiency, theΣ-Δ-modulator provides a better tracking performance for the DC/DC Buck converter. In this paper, an average control based on differential flatness was used to perform the experiments. It is worth mentioning that a different trajectory tracking controller could have been selected for this research.

Sign in / Sign up

Export Citation Format

Share Document