An Enhanced and Cost Saving Droop Control Method for Improved Load Sharing for the MEA Application

Abstract

The more electric aircraft (MEA) concept has been identified as the major trend of future aircraft. The DC distribution network is a promising architecture for more-electric aircraft application, where multiple electrical sources are connected to a common HVDC bus. The power sharing of these sources is achieved using the droop control method. However, the conventional droop control method has a limitation in achieving accurate load sharing and voltage regulation due to the influence of the cable resistance and nominal voltage reference offset. In this paper, a new method that modifies the droop gain according to the average total cable resistance for improved load sharing is proposed. The overall cable resistance of the system can be estimated based on the measurement of the total load current and knowledge of the value of the DC bus voltage. Also, since the method can be implemented locally without the need for a high-bandwidth communication link, it will save cost and reduce the system complexity. Based on the simulation results obtained, the proposed method has demonstrated better performance when compared to the conventional droop control method for the MEA application for any desired sharing ratio.