Energy management strategy design and station-keeping strategy optimization for high altitude balloon with altitude control system

The capacity of station-keeping and long endurance of renewable energy system have great impact on the application of the high altitude balloon. In this paper, the station-keeping mechanism based on an altitude control system is proposed to ride the natural wind field with diverse directions and speeds at different altitudes and then retain the balloon within the desired district. Combined with the energy harvesting/consuming model and the dynamic model, the energy management strategy is designed to extend the energy endurance of the balloon. The station-keeping strategy (the pumping/venting states of the air ballonet) based on the energy management strategy is optimized by the genetic algorithm. The optimization result shows that the air ballonet needs to be pumped 6 times and vented 5 times in one day. By pumping and venting the air ballonet, the balloon can be restricted within the district with a radius of 30 km and the maximum horizontal distance between the center of the district and the location of the balloon is about 28 km. In addition, the payload and the altitude control system can be powered by the PV array and the lithium battery sustainably. These results can assist in the design and initial flight tests of the serviceable high altitude balloon.