| Abstract |
DC microgrids have been widely used in distributed generation networks due to intermittent nature of renewables, low conversion losses, common interface with dc renewable sources and high reliability. In order to regulate the dc bus voltage and achieve proportional power sharing, the conventional V-dP/dV droop control strategy is performed by calculating the slope of tangent of P-V characteristic. However, the main challenges of this control scheme are poor dynamic behaviour and low quality of PV power. This paper presents a decentralized coordinated PV droop control method, which applies dP/dI for accurate energy distribution and faster response speed. Moreover, the inner control parameter d2P/dI2 is used to further minimize the PV power fluctuation in a steady state which allows to track the error with a corrective action. The proposed control strategy seamlessly transfers the MPPT algorithm to voltage regulation mode in a fully decentralized approach. Simulation study is conducted to demonstrate how the transient and dynamic responses have been significantly improved. |
