Voltage Stability Assessment and Power Regulation of Solar PV Based DC Microgrid

Increase in energy demand, Reduction in the available nonrenewable sources and need for reliable power supply has been main motivation for micro-grids. When many converters are interfaced to a common bus, there could be interaction among them which could lead to instability of the overall system. The varying efficiency due to solar source causes losses and resulting in using extra power to compensate the losses and wastage of available power. To improve the voltage regulation in the system, this paper proposes a Model reference adaptive controller (MRAC) designed with MIT (Massachusetts Institute of Technology) rule. MRAC validates the performance of the model by changing parameters in the adaptation gain. Our key contributions are: (1) To design DC Microgrid with higher efficiency and reliability with reduced fluctuations; (2) To preserve stability in the performance of Microgrid by MRAC controller and compared the results against baseline controllers; (3) To ensure power management of the system in case of islanding and maintains balanced flow of energy by effective load sharing. The performance of the controller is verified in MATLAB Simulink for different irradiations and it ensures stability of DC microgrid in all operating modes. A hardware prototype of the proposed system is implemented using DSP kit (TMS320F28335) with voltage and current sensors. Simulation and experimental results show that the proposed control strategy provides better output voltage regulation and stable response with short period of rise time, settling time of 1.5 s and overshoot of 6%.