A Review on an Electric Grid Stability in the Presence of Distributed Generation

As renewable energy sources are becoming more popular, the implementation of
distributed generation rather than a centralized generation has increased. Hence
microgrids are also becoming an essential part of the smart grid. As we move towards a
shortage in the availability of shorter non-renewable resources, the penetration of
distributed generations is increasing rapidly. The primary resource to implement the
distributed generation is through solar PV panels and wind turbines due to their
technological improvement in the research area. As we have diverse modes of power
generation such as solar, wind, hydro, and thermal, it is challenging to ensure their
parallel operation. When distributed generation systems penetrate the grid, several issues
will occur in the existing system, which causes the system to become unstable. If the
system's robustness needs to be analyzed, then the system's dynamic behavior during fault
conditions should be considered. The fault current level will not be the same if distributed
generation penetrates the system. The connection of distributed generation should not alter
the original power flow in the system. Hence a proper control mechanism should
implement when distributed generation is used in the system. This paper has gone through
the overview of distributed generation, operation, stability analysis, and different control
mechanisms to improve the Stability and drawbacks. These limitations present in the fuzzy
controller can overcome by designing and developing a unique controller called goal
representative heuristic dynamic programming controller. This controller will frequently
interact between the power plant and its control strategy, has more memory capacity, and
stores the data for future reference. This controller way overcomes the fuzzy controller's
limitations and can successfully be implemented in a grid in distributed generation.