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


  • 91 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

ShaghayeghKazemlou

Advisor: Dr. ShahabMehraeen

Louisiana State University

Advanced Mechanical Design

December 2008


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


Part I

Grid-connected Renewable System

Advanced Mechanical Design

December 2008


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

Solar power generation system

controller

dynamics

Synchronous Generator (SG)


Grid-Tie Inverter Model/Observer

SG dynamical equations

Inverter dynamical equations

( )

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


Part II

Converter Discrete-Time Model

Advanced Mechanical Design

December 2008


DC-DC Buck Converter

dc-dc buck converter control system

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


Converter Discrete-Time Model

  • Converter discrete-time equations

  • Photovoltaic array output current is a nonlinear function of


Part III

Converter Discrete-time Control Design

Advanced Mechanical Design

December 2008


State Feedback Controller

Input:

  • Tracking error :

stable


Neural Network function approximation

: activation function

  • Weight estimation error :

  • NN weight update law :

: positive design constant


Part IV

Simulation Results

Advanced Mechanical Design

December 2008


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 Results

  • Solar Voltage Less than MPP Voltage:

Converter input power

Converter input voltage

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


Simulation Results

  • Solar Voltage Less than MPP Voltage:

Converter output voltage

Converter inductance current

Converter input current


Simulation Results

  • Solar Voltage higher than MPP Voltage:

Converter input power

Converter input voltage

Converter output voltage


Simulation Results

  • Input Voltage Adjustment to Load Change:

Converter input power

Converter input voltage

Converter output voltage


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

  • 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.


Thank You for Your Attention


  • Login