Modeling PV based DC Micro Grid and to improve the stability margins with Non Linear Loads
With declining fossil fuel reserves and unfavourable economic trends, there has been an increased focus towards sustainable energy growth in Pakistan. The main theme of this project is to design and simulate a Grid Isolated Community DC Micro-grid with a high penetration of Photo-Voltaic
2025-06-28 16:34:10 - Adil Khan
Modeling PV based DC Micro Grid and to improve the stability margins with Non Linear Loads
Project Area of Specialization Electrical/Electronic EngineeringProject SummaryWith declining fossil fuel reserves and unfavourable economic trends, there
has been an increased focus towards sustainable energy growth in Pakistan. The main
theme of this project is to design and simulate a Grid Isolated Community DC
Micro-grid with a high penetration of Photo-Voltaic (PV) energy sources. In
literature DC Microgrids with linear loads (in radial connection) has been widely
studied, there has been a crucial lack of accurate models (mesh connected) to
represent the operations of real world ad hoc DC Microgrids. This project aims to
design and simulate the stable operation of such a DC Microgrid model in terms of
Voltage Stability. Design generated is simulated in MATLAB/Simulink to analyse
Voltage Stability. Our main focus is to simulate PV sources with Maximum Power
Point Tracking (MPPT) & non-linear loads (Electric Vehicles in particular). Effect of
non-linear loads on the Microgrid is observed and solution in form of Battery Energy
Storage System (BESS) is examined. This ensures the designed DC Microgrid
accounts for a wide variety of real life circumstances. There is a particular emphasis
towards rural communities and small/medium enterprise owners to assist them (in a
technical sense) in deciding the extent of their Microgrid investments.
- To design a robust model of low voltage grid isolated DC Microgrid and design mesh connections of said DC Microgrid to closely represent real life scenarios.
- To consider the destabilizing effect of Constant Power Loads. These loads make up the majority of loads in a DC Microgrid.
- To use data weather data sets and examine the effect on voltage stability of grid isolated DC Microgrids.
- To design suitable controllers (based on Sliding Mode, Neural Networks etc.) to allow communication less control of slack power sources in DC Microgrids
- To apply General Immittance Analysis or Lyapunov Stability analysis techniques in order to generalize stability of mesh connected DC Microgrid.
Project starts with the literature review of different research papers regarding the modelling and designing of DC Migrogrid and stabilility constartraints. By using the specifcations by these research papers the practicle design of the Microgrid will be made and simulated in the Matlab (Simulink) Software and there parameters will be optimized.After that the other Renewable sources such as Wind energy and Energy storage systems will be oimplemented in the model. For the operation of the model different controll strategies including PID Controllers. Droop Controllers will be employed ijn the model and thier working will be verified.
After the modelling of DC Microgrid (MG) is completed now the second phase will be started for statbility analysis of DC MG for different kinds of loads, different weather conditions with different sizes of the MG.
After stability evaluation the number of DC MG will be connected in mesh foprmation and current sharing controllers will be then employed between the grids to alow the DC Grids to share the load appropraitely. Atlast the general Immitance stability analysis will be done for the entiire system and then the dummy hardware will be employed for verification.
Benefits of the ProjectAs mentioned that the renewable sources are employed in the mesh formation, so the threat for the environmental pollution is drastically reduced by using renewables. Extraction of fossil fuels requires, cost time and labour but these are also reduced when these grids are connected to the AC grid system. Connection with AC system also increases relaibility of conventional system. In the shortage of the fossil fuels the DC Grids can support consderably if employed in large capacity.
Technical Details of Final DeliverableThe basic model of DC Microgrid has been designed and its voltage stability
has been explored using time-domain analysis. The effects of CPLs have been shown
on the DC Microgrid, as observed the power balance between PV Sources and DC
Loads is vital from the voltage stability point of view.
Protection and coordination is a necessary avenue for future exploration as
the current technology for DC protective relays is still immature.
? Economic viability in terms of capital and running cost of equipment is a
major hurdle for adoption of DC based power systems.
? Energy Management System (EMS) is another aspect to optimise to allow
best usage of smart grid protocols.
? Pricing and Tariff structure for consumers/producers has to be investigated in
order to improve economic viability compared to conventional power
systems.
? Hierarchical Communication enabled control of DC-DC Converters goes in
hand with the smart grid idea. Secondary and Tertiary level controllers can
allow for better power management and adapting to ad hoc changes in
structure of DC Microgrid.
| Item Name | Type | No. of Units | Per Unit Cost (in Rs) | Total (in Rs) |
|---|---|---|---|---|
| Total in (Rs) | 26500 | |||
| PV Panels | Equipment | 5 | 2000 | 10000 |
| DC-DC converters | Equipment | 5 | 1500 | 7500 |
| Inverters | Equipment | 5 | 1000 | 5000 |
| Metallic infrastructure | Miscellaneous | 1 | 3000 | 3000 |
| Connecting Wires Set | Miscellaneous | 1 | 1000 | 1000 |