1

SUPER-CAPACITORS ENERGY STORAGE SYSTEM APPLIED IN THE MICRO GRID

ByM.Venkata SaitejaP. Lohith Krishna

2

Contents:IntroductionOverview of the Micro GridWhat is meant by Super Capacitors?Super-Capacitors Energy Storage System

A)Charging & Discharging ModelB)Control Algorithm Design

Simulation ResultsConclusion

3

IntroductionDG(Distributed Generation) refers to power generation

at the point of consumption.The World Needs Distributed Generation that is Clean

and ContinuousAs the techniques of DG becoming more sophisticated,

the cost of the distributed power generation reducing, and a large number of distributed power generation equipments growing to be run.

4

DG would be able to solve the complex dynamic behavior and the safe and efficient operation of the high penetration of the microgrid is the key to whether the distributed power generation equipments can be used in the large-scale industrial applications.

Current study is about internal mechanism of micro grid.

5

A small-scale power grid that can operate independently or in conjunction with the area's main electrical grid.

6

What is meant by Super Capacitors?It is a new type of energy storage device between the

common capacitor and the secondary battery based on the electrochemical double-layer principle

It is reversible with no chemical reactions. Therefore, the super capacitor can be repeated charge

and discharge hundreds of thousands of times. Its power density is 10-100 times more than that of

conventional batteries

7

Charge and Discharge characteristics of Super Capacitor

Charging Mode

Constant Voltage

Charging Mode

Constant Current

Charging Mode

Discharging Mode

Constant Power

Discharging Mode

8

Super-Capacitors Energy Storage SystemA)Charging & Discharging Model

Fig . Main circuit model of Boost-Buck

9

Charging and Discharging Model

Under Charging Under Discharging• P1- Manages Energy flow• P2- off• It is a Buck Converter• It uses a Constant Power

Discharging Mode• =

10

Control Algorithm DesignI. Process of Constant Current Charging ControlII. Process of Constant Voltage Charging ControlIII. Process of Discharge Control

11

Constant Current Charging Control• Hysteresis compared mode is

used• Width of hysteresis loop

determines the tracking performance

• If ring width is too large, switching frequency will be low, tracking error increases.

• If ring width is too low, higher switching frequencies takes place which may cause the loss increases

Fig. Block diagram of constant current charging control

12

Constant Voltage Charging Control

• Triangular wave comparison method is used

• Error will go through the triangle-wave comparator to generate PWM waveform to control the switching device

Fig. Block diagram of constant voltage charging control

13

Discharge Control

• Direct current control is used

• Output go through the triangle-wave comparator to generate PWM waveform to control the switching device

Fig. Block diagram of discharging control

Simulation Results

Fig. Terminal Voltage curve of super capacitors Fig. Current curve of super capacitors Fig. Voltage of DC Bus

14

15

SummaryOverview of Micro Grid

A brief about Super Capacitors

Charging and Discharging Model

Control Algorithm Design

Simulation Results

Conclusion:• It compensate the energy effectively when the voltage sag occurred in

the bus of the micro grid.• It provides energy storage system to restrain the bus voltage

fluctuations in the micro grid.

16

17

References

[1] Wu Bingbing, Yin Zhongdong, Xiao Xiangning, “Super-capacitors Energy Storage System Applied in the Microgrid”, Industrial Electronics and Applications(ICIEA), 5th IEEE conference, pp. 1002-1005, 15-17 June, 2010.

[2] Jingwei Hu, Tieyan Zhang, Shipeng Du and Yan Zhao, “An Overview on Analysis and Control of Micro-grid System”, International Journal of Control and Automation, Vol. 8, No. 6, pp. 65-76, July, 2015.

[3] Rosario Carbone, “Energy Storage in the Emerging Era of Smart Grids”, Croatia, pp. 21-38, September, 2011.

[4] HUANG Wei, SUN Chang-hui, WU Zi-ping, etc. “A Review on Microgrid Technology Containing Distributed Generation System”, Power System Technology, pp. 14-19, April, 2009.

[5] LU Hongyi, HE Benteng. “Application of the Super-capacitor in a MicroGrid”, Automation of Electric Power Systems, pp. 87-91, 2009.

[6] “Distribution Systems and Dispersed Generation”, Elecrama, 9 January, 2014.

18

Thank u

Contact Us M.Venkata Saiteja P.Lohith Krishna +919160113431 +919700052897 venkatasaiteja95@gmail.com lohithkrishna2013@gmail.com