A Generator-Powered Electric Variable-Pitch Drive System for the High-Performance Regulation of Propeller

With the development of variable-pitch system (VPS), the propulsion efficiency of more electric aircraft (MEA) is greatly improved. But the conventional VPS requires an external battery pack for power supply, which increases the total weight of the system and reduces the fuel efficiency. This paper proposes a generator-powered variable-pitch system (GVPS). The proposed system uses a generator mechanically connected to the propeller instead of the power battery pack. To ensure smooth operation of the GVPS, this paper adopts the power feedforward algorithm based on Nonlinear Disturbance Observer (NDOB) which can mitigate the bus voltage fluctuations caused by abrupt changes in load power. Simulation and experimental results verify the feasibility of the proposed system.

I. Introduction

Compared with pneumatic or hydraulic systems, electric VPS has advantages such as simple design, quick response, energy efficiency, and low maintenance costs [1]–[2]. As a result, it has been widely used in MEA. Electric VPS requires a power battery pack to supply power to the entire system. But power batteries have lower energy density compared with hydraulic or pneumatic systems [3], which results in a greater mass for the electric VPS under equivalent energy requirements, and affects their flight performance. Moreover, the electric VPS is located near the aircraft propellers, operating in harsh environments. Power battery packs often fail to reach their theoretical design limits in practical application [4]. So reserving sufficient margin for power battery packs of the traditional electric VPS is essential, which further increases the weight and cost of MEA. So reducing battery mass, extending battery endurance, and enhancing battery lifespan are crucial factors constraining the development of MEA [5]. But it is hard to solve these problems.