Abstract:
Gravity energy storage utilizes the height difference to lift and lower the solid heavy energy storage medium,achieving the charging and discharging of the energy storage system. Compared with pumped storage, it has a wide range of application prospects due to its lack of dependence on water resources and flexible site selection. To improve the charging and discharging operating efficiency of gravity energy storage systems, this article investigates the multi-machine coordinated control problem of a vertical matrix type gravity energy storage system, aiming at minimizing power circulation in parallel with multiple machines. Firstly, a vertical matrix gravity energy storage system model is constructed based on PSCAD/EMTDC,and its charging and discharging characteristics are analyzed.Secondly, a coordinated control method for multiple units based on the dual layer control architecture of gravity energy storage array is proposed by analyzing the power circulation mechanism and suppression problem generated by the parallel operation of multiple units in the gravity energy storage system. This method can quickly meet the power charging and discharging needs of the power grid while minimizing the power circulation between parallel operating units, improving the charging and discharging operating efficiency of the gravity energy storage system.Finally, the simulation results verify the effectiveness of the above multi machine coordinated control strategy.