Stability Analysis and Active Stabilizer Design of The Bipolar DC Power System Feeding Constant Power Loads for Unmanned Aerial Vehicle

In the electric unmanned aerial vehicle, the bipolar DC power system is a good choice to provide power for airborne equipment because of its high efficiency and reliability. However, the constant power loads in bipolar DC power system can reduce the system damping and makes the system underdamped or even unstable. To reveal the instability mechanism of bipolar DC power system, firstly, the eigenvalue method is adopted to analyze the effect of controller parameters, constant power loads, constant current loads, and constant resistance loads on stability. Secondly, the active stabilizer is proposed to extend stability margin, which uses a high pass filtered voltage of DC bus following with a proportional compensator. Finally, the loads step tests are completed by MATLAB/Simulation. The simulation results verify the effectiveness of the active stabilizer and show a conservative zone of stability analysis between eigenvalue analysis and simulation.