scholarly journals Digital Control of a Buck Converter Based on Input-Output Linearization. An Interpretation Using Discrete-Time Sliding Control Theory

Energies ◽  
2019 ◽  
Vol 12 (14) ◽  
pp. 2738
Author(s):  
Enric Vidal-Idiarte ◽  
Carlos Restrepo ◽  
Abdelali El Aroudi ◽  
Javier Calvente ◽  
Roberto Giral
Keyword(s):  
Discrete Time ◽  
Digital Control ◽  
Output Voltage ◽  
Power Converter ◽  
Current Control ◽  
Buck Converter ◽  
Control Loop ◽  
Input Output ◽  
Analysis And Design ◽  
Input Output Linearization

This paper presents the analysis and design of a PWM nonlinear digital control of a buck converter based on input-output linearization. The control employs a discrete-time bilinear model of the power converter for continuous conduction mode operation (CCM) to create an internal current control loop wherein the inductor current error with respect to its reference decreases to zero in geometric progression. This internal loop is as a constant frequency discrete-time sliding mode control loop with a parameter that allows adjusting how fast the error is driven to zero. Subsequently, an outer voltage loop designed by linear techniques provides the reference of the inner current loop to regulate the converter output voltage. The two-loop control offers a fast transient response and a high regulation degree of the output voltage in front of reference changes and disturbances in the input voltage and output load. The experimental results are in good agreement with both theoretical predictions and PSIM simulations.

scholarly journals Input-output based quasi-sliding mode control of DC-DC converter

2012 ◽  
Vol 25 (1) ◽  
pp. 69-80 ◽  
Author(s):  
Darko Mitic ◽  
Dragan Antic ◽  
Marko Milojkovic ◽  
Sasa Nikolic ◽  
Stanisa Peric
Keyword(s):  
Discrete Time ◽  
Output Voltage ◽  
Control Algorithm ◽  
Sliding Mode ◽  
Buck Converter ◽  
Sliding Mode Controller ◽  
Input Output ◽  
Load Variations ◽  
Voltage Controller ◽  
Derivatives Of

The paper presents the design of discrete-time quasi-sliding mode voltage controller for DC-DC buck converter. The control algorithm is realized by measuring only sensed output voltage. No current measurements and time derivatives of output voltage are necessary. The proposed quasi-sliding mode controller provides stable output voltage, exhibiting robustness to parameter and load variations.

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 Analysis and Design for Output Voltage Regulation in Constant-on-Time-Controlled Fly-Buck Converter

Electronics ◽  
2021 ◽  
Vol 10 (16) ◽  
pp. 1886
Author(s):  
Younghoon Cho ◽  
Paul Jang
Keyword(s):  
Output Voltage ◽  
Voltage Regulation ◽  
Design Guidelines ◽  
Buck Converter ◽  
Design Guideline ◽  
Analysis And Design ◽  
Flyback Converter ◽  
Auxiliary Power ◽  
Primary Output ◽  
Output Capacitor

Fly-buck converter is a multi-output converter with the structure of a synchronous buck converter structure on the primary side and a flyback converter structure on the secondary side, and can be utilized in various applications due to its many advantages. In terms of control, the primary side of the fly-buck converter has the same structure as a synchronous buck converter, allowing the constant-on-time (COT) control to be applied to the fly-buck converter. However, due to the inherent energy transfer principle, the primary-side output voltage regulation of COT controlled fly-buck converters may be poor, which can deteriorate the overall converter performance. Therefore, the primary output capacitor must be carefully designed to improve the voltage regulation characteristics. In this paper, a theoretical analysis of the output voltage regulation in COT controlled fly-buck converter is conducted, and based on this, a design guideline for the primary output capacitor considering the output voltage regulation is presented. The validity of the analysis and design guidelines was verified using a 5 W prototype of the COT controlled fly-buck converter for telecommunication auxiliary power supply.

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.

A 65-nm, 1-A Buck Converter With Multi-Function SAR-ADC-Based CCM/PSK Digital Control Loop

2012 ◽  
Vol 47 (7) ◽  
pp. 1546-1556 ◽  
Author(s):  
Sébastien Cliquennois ◽  
Achille Donida ◽  
Piero Malcovati ◽  
Andrea Baschirotto ◽  
Angelo Nagari
Keyword(s):  
Digital Control ◽  
Buck Converter ◽  
Sar Adc ◽  
Control Loop

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.

scholarly journals Discrete-Time DC-Link Voltage and Current Control of a Grid-Connected Inverter with LCL-Filter and Very Small DC-Link Capacitance

Energies ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 5613 ◽  
Author(s):  
Oliver Kalmbach ◽  
Christian Dirscherl ◽  
Christoph M. Hackl
Keyword(s):  
Discrete Time ◽  
Controller Design ◽  
Linear Quadratic Regulator ◽  
Current Control ◽  
Control Loop ◽  
Linear Quadratic ◽  
Lcl Filter ◽  
Current Controller ◽  
Voltage Controller ◽  
Grid Connected Inverter

The paper presents a controller design for grid-connected inverters (GCI) with very small dc-link capacitance that are coupled to the grid via an LCL filter. The usual controller designs would fail and result in instability. The proposed controller has a cascaded structure with a current controller as inner control loop and an outer dc-link voltage controller. The controller design is performed in discrete time and it is based on a detailed stability analysis of the dc-link voltage controller to determine the controller parameters which guarantee stability for all operating points. The inner loop is a state-feedback current controller that is designed based on the discrete linear-quadratic regulator (DLQR) theory. An additional integral error feedback assures steady-state accuracy of the current control loop. The simulation and experimental results validate performance and stability of proposed controller design.

Sign in / Sign up

Export Citation Format

Share Document