Ecosense establishes 30 kW Smart Hybrid AC/DC Microgrid Solution Research Lab at VIT University, Vellore
The Lab is established in SENSE department of VIT University, Vellore.
Renewable energy based microgrids will play a dominant role in electricity production in near future. Distributed generation based on wind, solar energy, fuel cell, battery storage along with use of super capacitors will give significant momentum in near future. Advantages like environmental friendliness, expandability and flexibility have made distributed generation, powered by various renewable and nonconventional micro sources, an attractive option for configuring modern electrical grids. A micro-grid consists of cluster of loads and distributed sources that operate as a single controllable system. As an integrated energy delivery system microgrid can operate in parallel or isolated from the main power grid.
The Microgrid
Smart Hybrid Microgrid Solution
In Smart Hybrid Micro-Grid Solution, the performance of hybrid AC/DC microgrid system is analyzed in the grid tied mode. Here photovoltaic system, wind turbine generator, super capacitors, fuel cell and battery are used for the development of microgrid. Also control mechanisms are implemented for the converters to properly coordinate the AC sub-grid to DC sub-grid. The results are obtained from the LabVIEW environment.
Control is achieved through dc bus voltage monitoring and control operations on the interfacing converters, based on predefined voltage set points. As an interfacing converter, a bi-directional, a cascaded boost, buck and boost converter is used and controlled.
Energy Sources
There are three different kinds of renewable energy sources used in this project:
1. Wind Turbine Emulator
As this project is established to carry on research, instead of using actual Wind Turbine a 10kW PMSG based Wind Turbine Emulator developed by Ecosense is used in this project. Wind Turbine Emulator eliminates the dependence on environmental condition and facilitates smooth operation though out the day inside lab.
2. Solar PV Emulator
Similar to Wind Emulator, a 10kW Solar PV Emulator developed by Ecosense is used in this project. Solar PV Emulator can work at any time of the day eliminating the dependency on environmental factors.
3. Fuel Cell system
A 1kW actual fuel cell system is used as the third source. As Fuel Cell do not depend on environment but on availability of Hydrogen gas, an actual fuel cell system is used in this project.
The Microgrid
Energy Storage
As it is a grid connected system there is no use of energy storage devices but in case of failure of grid these energy storage devices play an active role. In this project two different energy storage systems are used:
1. 5kWh Li-ion battery bank.
2. 288 V, 55 F Supercapacitor bank.
Electrical Loads
A three phase 10kW programmable RLC load is used for loading the system. Also, as the system is connected to grid, instead of connecting the hybrid system directly to main electrical grid a 30kVA Grid Emulator is used in between. Grid Emulator facilitates the research in grid side where a user can implement fault conditions to check the reliability and efficiency of the grid.
The Block Diagram
Scope and Applications of Smart Hybrid Micro-Grid Solution
• Ability to track torque-speed and power-speed characteristics of a wind turbine at different wind speeds and pitch angle
• Plotting Cp-λ curve to show the turbine characteristics at a particular pitch angle
• Real time tracking of λ could be utilized to track the optimal λ of a turbine
• Maximum power point tracking opportunity based on the generated voltage and current feedback
• Ability to control DC link voltage using bidirectional converter in stand-alone mode
• Research on microgrid possible as the DC link can accommodate other renewable sources such as PV
• Comparative analysis of different PV panels using PV emulator
• Series-parallel behavior of different PV panels could be analyzed for both stand-alone and grid connected systems
• Power flow and quality supplied to the grid can be controlled and analyzed
• Further exploration of control techniques for smart grid implementation possible
• Continuous sensing of grid side voltage and currents provide opportunity to implement advanced control algorithms to control the behavior as per grid conditions
• Cloud Computing System