scholarly journals Review and Selection Strategy for High-Accuracy Modeling of PWM Converters in DCM

2018 ◽  
Vol 2018 ◽  
pp. 1-16
Author(s):  
Yu-Jun Mao ◽  
Chi-Seng Lam ◽  
Sai-Weng Sin ◽  
Man-Chung Wong ◽  
Rui Paulo Martins
Keyword(s):  
Closed Loop ◽  
Transfer Functions ◽  
High Accuracy ◽  
Operating Conditions ◽  
Selection Strategy ◽  
Small Signal ◽  
Pwm Converters ◽  
Modeling Methods ◽  
The Past ◽  
Conduction Mode

Among various modeling methods for DC-DC converters introduced in the past two decades, the state-space averaging (SSA) and the circuit averaging (CA) are the most general and popular exhibiting high accuracy. However, their deduction approaches are not entirely equivalent since they incorporate different averaging processes, thus yielding different small signal transfer functions even under identical operating conditions. Some research studies claimed that the improved SSA can obtain the highest accuracy among all the modeling methods, but this paper discovers and clearly verifies that this is not the case. In this paper, we first review and study these two modeling methods for various DC-DC converters operating in the discontinuous conduction mode (DCM). We also streamline the general model-deriving processes for DC-DC converters, and test and compare the accuracy of these two methods under various conditions. Finally, we provide a selection strategy for a high-accuracy modeling method for different DC-DC converters operating in DCM and verified by simulations, which revealed necessary and beneficial for designing a more accurate DCM closed-loop controller for DC-DC converters, thus achieving better stability and transient response.

EXPERIMENTAL RESULTS FOR THE SMALL-SIGNAL STUDY OF THE PWM BOOST DC–DC CONVERTER WITH AN INTEGRAL-LEAD CONTROLLER

1995 ◽  
Vol 05 (04) ◽  
pp. 747-755 ◽  
Author(s):  
MARIAN K. KAZIMIERCZUK ◽  
ROBERT C. CRAVENS, II
Keyword(s):  
Closed Loop ◽  
Transfer Functions ◽  
Low Frequency ◽  
Input Voltage ◽  
Open Loop ◽  
Small Signal ◽  
Loop Control ◽  
Pulse Width Modulated ◽  
Bode Plots ◽  
Step Responses

An experimental verification of previously derived small-signal low-frequency open- and closed-loop characteristics and step responses of a voltage-mode-controlled pulse-width-modulated (PWM) boost DC–DC converter is presented. The Bode plots of the voltage transfer function of the control circuit, the converter and the PWM modulator, the open-loop control-to-output and input-to-output transfer functions, the loop gain, and the closed-loop control-to-output and input-to-output transfer functions are measured. The step responses to the changes in the input voltage, the duty cycle, and the reference voltage are measured. The theoretical results were in good agreement with the measured results. The small-signal model of the converter is experimentally verified.

scholarly journals Influence of output conductance on characteristic frequencies of switch mode BUCK and BOOST converter

2017 ◽  
Vol 66 (1) ◽  
pp. 165-178
Author(s):  
Włodzimierz Janke ◽  
Marcin Walczak
Keyword(s):  
Transfer Functions ◽  
Signal Control ◽  
Small Signal ◽  
Main Attention ◽  
Characteristic Frequencies ◽  
Switch Mode ◽  
Good Consistency ◽  
Poles And Zeros ◽  
Conduction Mode ◽  
Output Conductance

Abstract Characteristic frequencies corresponding to poles and zeros of small-signal control-to-output transfer functions of popular DC-DC converters (BUCK and BOOST) are analyzed. The main attention is paid to influence of load conductance on the characteristic frequencies for converters working in continuous conduction mode (CCM) as well as in discontinuous conduction mode (DCM). Parasitic resistances of all converter components are included in calculations. In addition the improved description of CCM-DCM boundary is presented. The calculations are verified experimentally and good consistency of the results is observed.

scholarly journals Modeling and control of a three-phase isolated grid-connected converter for photovoltaic applications

2011 ◽  
Vol 22 (3) ◽  
pp. 215-228 ◽  
Author(s):  
Marcelo Gradella Villalva ◽  
Marcos Fernando Espindola ◽  
Thais Gama de Siqueira ◽  
Ernesto Ruppert
Keyword(s):  
Output Voltage ◽  
Closed Loop ◽  
Transfer Functions ◽  
Voltage Source ◽  
Small Signal ◽  
Modeling And Control ◽  
Photovoltaic Array ◽  
Three Phase ◽  
Photovoltaic Applications ◽  
And Control

This paper describes the modeling and control of a three-phase grid-connected converter fed by a photovoltaic array. The converter is composed of an isolated DC-DC converter and a three-phase DC-AC voltage source inverter The converters are modeled in order to obtain small-signal transfer functions that are used in the design of three closed-loop controllers: for the output voltage of the PV array, the DC link voltage and the output currents. Simulated and experimental results are presented.

OPEN- AND CLOSED-LOOP DC AND SMALL-SIGNAL CHARACTERISTICS OF PWM BUCK-BOOST CONVERTER FOR CCM

1995 ◽  
Vol 05 (03) ◽  
pp. 261-303 ◽  
Author(s):  
MARIAN K. KAZIMIERCZUK ◽  
ROBERT CRAVENS
Keyword(s):  
Transfer Function ◽  
Closed Loop ◽  
Transfer Functions ◽  
Voltage Divider ◽  
Boost Converter ◽  
Open Loop ◽  
Equivalent Series Resistance ◽  
Small Signal ◽  
Offset Voltage ◽  
Parasitic Components

DC and small-signal circuit models of the PWM buck-boost converter for the continuous conduction mode (CCM) are derived. The models take into account parasitic components, such as the equivalent series resistance (ESR) of the filter capacitor, the ESR of the inductor, the transistor on-resistance, and the diode forward resistance and offset voltage. The component values and the parasitics were measured for a prototype converter. The dc voltage transfer function and the efficiency of the converter are derived from the dc model. Small-signal open-loop transfer functions are derived from the small-signal model. The derivation of the transfer function for an integral-lead controller with the loading effect of the voltage divider network in the feedback loop is given. Small-signal closed-loop transfer functions are derived. Bode plots are given for various transfer functions of the converter.

Comparison of Dc-Dc SEPIC, CUK and Flyback Converters Based LED Drivers

2020 ◽  
pp. 99-107
Author(s):  
Erdal Sehirli
Keyword(s):  
Integrated Circuit ◽  
Closed Loop ◽  
Input Voltage ◽  
Open Loop ◽  
Current Sensor ◽  
Switching Frequency ◽  
Led Driver ◽  
Advantages And Disadvantages ◽  
Led Drivers ◽  
Conduction Mode

This paper presents the comparison of LED driver topologies that include SEPIC, CUK and FLYBACK DC-DC converters. Both topologies are designed for 8W power and operated in discontinuous conduction mode (DCM) with 88 kHz switching frequency. Furthermore, inductors of SEPIC and CUK converters are wounded as coupled. Applications are realized by using SG3524 integrated circuit for open loop and PIC16F877 microcontroller for closed loop. Besides, ACS712 current sensor used to limit maximum LED current for closed loop applications. Finally, SEPIC, CUK and FLYBACK DC-DC LED drivers are compared with respect to LED current, LED voltage, input voltage and current. Also, advantages and disadvantages of all topologies are concluded.

A Comparison of Two Sub-structuring Techniques for Representing the Modal Properties of Tires

2001 ◽  
Vol 29 (1) ◽  
pp. 23-43 ◽  
Author(s):  
D. Tsihlas ◽  
T. Lacroix ◽  
B. Clayton
Keyword(s):  
Automobile Industry ◽  
Dynamic Models ◽  
Transfer Functions ◽  
Component Mode Synthesis ◽  
Numerical Techniques ◽  
The Past ◽  
Custom Made ◽  
Modal Behavior ◽  
Noise Vibration ◽  
Reduced Dynamic

Abstract Different numerical sub-structuring techniques for the representation of tire modal behavior have been developed in the past 20 years. By using these numerical techniques reduced dynamic models are obtained which can not only be used for internal studies but also be provided to the automobile industry and linked to reduced dynamic vehicle models in order to optimize the coupled vehicle-tire response for noise vibration and harshness purposes. Two techniques that have been developed in a custom-made finite element code are presented: 1) the component mode synthesis type models for which the wheel center interface is free and 2) the Craig and Bampton type models for which the wheel center interface is fixed. For both techniques the interface between the tire and the ground is fixed. The choice of fixed or free wheel center boundary condition is arbitrary. In this paper we will compare the formulation of these two numerical methods, and we will show the equivalency of both methods by showing the results obtained in terms of frequency and transfer functions. We will show that the two methods are equivalent in principle and the reduced dynamic models can be converted from one to the other. The advantages-disadvantages of each method will be discussed along with a comparison with experimentally obtained results.

scholarly journals SVM based pattern recognised islanding detection approach in a multiple distributed generation system

2018 ◽  
Vol 7 (1.8) ◽  
pp. 228 ◽  
Author(s):  
Gundala Srinivasa Rao ◽  
G. Kesava Rao
Keyword(s):  
Distributed Generation ◽  
High Accuracy ◽  
Islanding Detection ◽  
Generation System ◽  
Detection Zone ◽  
The Past ◽  
Detection Approach

The penetration of Distributed generation (DG) ensures the increase of demand for consistent, reasonable and spotless electricity facing with some design and operational challenges such as islanding. Several active and passive methods have been suggested in the past to detect islanding. Since they suffer from the large non detection zone and a high cost. In order to defeat such issues we propose a SVM based pattern recognising approach for islanding detection in a multiple DG system. The results show that our proposed method detects islanding with high accuracy.

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