Modeling, Operation and Control of an AC microgrid in Grid-Connected and Islanded Model

Project Title

Modeling, Operation and Control of an AC microgrid in Grid-Connected and Islanded Model

Project Area of Specialization Electrical/Electronic EngineeringProject Summary

 The microgrid is a small-scale, local distribution system consisting of generation and load.  Microgrids work locally and in case of a fault, it works in an islanded mode called standalone mode. The standalone microgrid is nothing but a small scale power grid without any utility.
An AC microgrid connects to the distribution network via an AC bus, and the AC bus controls the microgrid’s connection to and disconnection from the distribution network through the circuit breaker at the PCC. The advantage of the AC microgrid is that as the microgrid is connected to the grid through an AC bus, no inverter is required for power supply to AC loads. In an alternating current microgrid, all distributed energy resources and loads are connected to a common AC bus.

AC microgrid works on two modes of operation. When supplied energy is sufficient for all load demands, microgrids send out energy to the utility grid. Otherwise, the microgrid absorbs energy from the grid.
A microgrid has two modes of operation,
1. Grid  Connected Mode: The normal operating mode of the microgrid is the grid-connected mode.  In this operating mode, all the feeders are being supplied by utility or main grid.  Microgrid operates without any power quality disturbance on the main grid
 2. Islanded Mode: In the islanded mode of operation, microgrids disconnect from the main grid whenever fault or any other power disturbance occurs

It will provide efficient, low-cost, and clean energy. It'll improve the operation and stability of the regional electric grid. It has the critical infrastructure that increases reliability and resilience. It'll reduce grid “congestion” and peak loads.

 In this project, an AC microgrid is modeled with its own sources (such as the synchronous generator, photovoltaic sources, wind turbine), its own storage devices (like Li-ion batteries), controllers to perform specific actions, and loads. All these components are connected to each other through an AC bus bar and this AC bus bar is connected to the main AC bus bar through a circuit breaker and then the main bus bar is connected to the main grid. AC microgrid in this project is operated and controlled in two modes i.e. grid-connected mode and islanded mode as explained above.

A very simple block diagram of the proposed AC microgrid is shown in the link below.

https://drive.google.com/file/d/1rTIs5tIBl6CMrqSuRhPS1siA_UfYuEZo/view?usp=sharing

Project Objectives

1. To model different AC micro-grid components such as diesel engine generators, photovoltaic sources, wind turbines, battery energy storage, and loads

2. To simulate control technique/s for an efficient operation of AC microgrid in grid-connected or/and islanded mode of operation

3. To implement hardware prototypes for an AC microgrid

Project Implementation Method

The project is proposed to be implemented by following the steps mentioned below.

1. Literature review for the transient and steady-state model of different components of AC microgrid

2. Simulation of models proposed in step 1 to check their validity

3. Literature review for different control techniques for the grid-connected and islanded mode of operation for the proposed AC microgrid

4. Design and simulation of the control techniques for grid-connected and islanded mode for proposed AC microgrid

5. Implementation of hardware prototypes for the validation of the proposed control techniques for the proposed AC microgrid

Benefits of the Project

The project will benefit in the following ways.

1. To our best understanding, this is the first project of its kind that is going to be worked on in our university. In this way, it shall help future students to work in the field of microgrids and smart grids

 2. This project will give a comprehensive review of different models that can be used for modeling different microgrid components

3. This project will analyze the suitability of different control techniques that can be used for controlling AC microgrid for a grid-connected and islanded mode of operation. In this way, it will help towards understanding the behavior of an AC microgrid for its operation in the grid-connected and islanded mode of operation

4. This project will give a hardware prototype for the proposed AC microgrid. In this way, it will give a test bench for future work on microgrids in our university

5. This project is based on the operation and control of microgrids in their different operational modes. Microgrids are found to be the best unit for the integration of renewable energy sources in conventional grids, so this shall lead to a higher penetration of renewable energy sources which is the future demand of our country

Technical Details of Final Deliverable

This project is aimed to deliver the following.

1. A comprehensive review of different models that can be used for modeling different microgrid components under different grid operating states in the form of a research paper

2. Simulation models of different control techniques that can be used for controlling an AC microgrid for the grid-connected and islanded mode of operation for analyzing the suitability of a control technique under a particular condition

3. Hardware prototype for grid integrated and stand-alone operation of photovoltaic sources, diesel generator, and constant power loads

Final Deliverable of the Project HW/SW integrated systemCore Industry OthersOther Industries Education , Energy Core Technology OthersOther Technologies Artificial Intelligence(AI), Internet of Things (IoT), Shared EconomySustainable Development Goals Affordable and Clean EnergyRequired Resources

Item Name	Type	No. of Units	Per Unit Cost (in Rs)	Total (in Rs)
			Total in (Rs)	57580
Rectifier	Equipment	5	100	500
Switches for inverter	Equipment	18	2000	36000
Gate drivers components	Equipment	9	120	1080
Printed circuit boards	Equipment	6	1000	6000
Controllers	Equipment	3	3000	9000
Miscellaneous	Miscellaneous	1	5000	5000