Discrete time modeling and control of dc dc switching converter for solar energy systems
This presentation is the property of its rightful owner.
Sponsored Links
1 / 21

Discrete Time Modeling And Control Of DC/DC Switching Converter For Solar Energy Systems PowerPoint PPT Presentation


  • 89 Views
  • Uploaded on
  • Presentation posted in: General

Discrete Time Modeling And Control Of DC/DC Switching Converter For Solar Energy Systems. Shaghayegh Kazemlou Advisor : Dr. Shahab Mehraeen Louisiana State University. Advanced Mechanical Design December 2008. Outline. Part I: Grid-connected Renewable System

Download Presentation

Discrete Time Modeling And Control Of DC/DC Switching Converter For Solar Energy Systems

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript


Discrete time modeling and control of dc dc switching converter for solar energy systems

Discrete Time Modeling And Control Of DC/DC Switching Converter For Solar Energy Systems

ShaghayeghKazemlou

Advisor: Dr. ShahabMehraeen

Louisiana State University

Advanced Mechanical Design

December 2008


Outline

Outline

  • Part I: Grid-connected Renewable System

  • Part II: Converter Discrete-Time Model

  • Part III: Converter Discrete-time Control Design

  • Part IV: Simulation Results

  • Part V: Summary and Future Works


Grid connected renewable system

Part I

Grid-connected Renewable System

Advanced Mechanical Design

December 2008


Solar system model

Solar System Model

  • Solar panels

  • DC-DC buck converter

  • Grid-tie inverter (GTI)

Solar power generation system

  • stabilizing the inverter DC-link capacitor

  • Omitting solar power oscillations

Objective


Grid tie inverter

Grid-Tie Inverter

Solar power generation system

controller

dynamics

Synchronous Generator (SG)


Grid tie inverter model observer

Grid-Tie Inverter Model/Observer

SG dynamical equations

Inverter dynamical equations

( )

  • Inverter gain ( ) and ac voltage angle ( ) are the control inputs


Converter discrete time model

Part II

Converter Discrete-Time Model

Advanced Mechanical Design

December 2008


Dc dc buck converter

DC-DC Buck Converter

dc-dc buck converter control system

  • Objective: Maintaining the solar power constant by adjusting duty cycle d


Converter discrete time model1

Converter Discrete-Time Model

  • Converter discrete-time equations

  • Photovoltaic array output current is a nonlinear function of


Converter discrete time control design

Part III

Converter Discrete-time Control Design

Advanced Mechanical Design

December 2008


State feedback controller

State Feedback Controller

Input:

  • Tracking error :

stable


Neural network function approximation

Neural Network function approximation

: activation function

  • Weight estimation error :

  • NN weight update law :

: positive design constant


Simulation results

Part IV

Simulation Results

Advanced Mechanical Design

December 2008


Simulation results1

Simulation Results

  • System parameters

  • AVR+PSS mechanism for inverter

  • operational frequency of the converter : 10 kHz

  • three-phase resistive load with on each phase

  • Disturbance : load change from to at

  • solar module maximum power :

  • solar module maximum power point voltage :


Simulation results2

Simulation Results

  • Solar Voltage Less than MPP Voltage:

Converter input power

Converter input voltage

  • Disturbance between t=1.4s to t=1.6s


Simulation results3

Simulation Results

  • Solar Voltage Less than MPP Voltage:

Converter output voltage

Converter inductance current

Converter input current


Simulation results4

Simulation Results

  • Solar Voltage higher than MPP Voltage:

Converter input power

Converter input voltage

Converter output voltage


Simulation results5

Simulation Results

  • Input Voltage Adjustment to Load Change:

Converter input power

Converter input voltage

Converter output voltage


Summary

Summary

  • The inverter is controlled bya novel stabilizer similar to power system stabilizer (PSS).

  • The interaction of the solar array dc-dc converter with the GTI is addressed.

  • A nonlinear discrete-time model of a photovoltaic-connected buck converter was presented.

  • Adaptive neural network (NN) controller is employed to enhance stability of dc-dc converter connected to grid-tie inverter (GTI) in the presence of power system disturbances.

  • Simulation results of the controller imply that the converter input voltage and power as well as the inductor current are stabilized which verifies the accuracy of the converter discrete-time model and the effectiveness of the proposed discrete-time controller.


Recommendations for future works

Recommendations for Future Works

  • Improve the efficiency and effectiveness of discrete-time adaptive neural network in the power system stability and control

  • The system model can be developed to a more general distributed generation system where other renewable generators or synchronous generators all are interconnected. In this case each system is influenced by other subsystem’s states and a more general control method is necessary.

  • The solar system connected dc-dc converter can be modeled in a dc distribution system with interconnected subsystems working in high penetration of renewable generation.


Discrete time modeling and control of dc dc switching converter for solar energy systems

Thank You for Your Attention


  • Login