Control System of PV Source for DC Distribution System With Seamless Operation Transition Between I-V Droop Control and Current Control for MPPT

As one of the decentralized control methods for the DC microgrid, DC bus signaling have been considered which change an operation mode of each connected converter based on a bus voltage. In a DC-DC converter for photovoltaics, there are conventional control methods that changes between maximum power point tracking control and V-P droop or V-I droop control based on the bus voltage. To reduce design and implementation costs, this article proposed a control method of photovoltaic DC-DC converter on DC distribution system which change operations between photovoltaic side current control for maximum power point tracking and I-V droop control based on DC bus signaling. The proposed method can reduce the number of controllers compared to conventional methods while achieving the same steady-state characteristics. Through the prototype experiment of a boost DC-DC converter with output voltage rate of 48 V and a maximum power of 130 W, it was confirmed that the desired control characteristics of the proposed method was realized. It was also verified that the proposed method was more stable and responsive than the conventional method with same power stage.