Scenery Storage System Energy Storage Battery Charging And Discharging Control Strategy Research

With the rapid development of wind power generation and solar power generation, the stability control problems need to be solved seriously because of the randomness and intermittent of wind and solar resource in Wind/PV/Storage system. By combining storage batteries with stability and smoothly controlled, the quality requirements from the scheduling of the power grid will be met and the quality of injected power will be assured for grid-connected hybrid generation system. Therefore, the stability and smooth control of the battery energy storage system has become the key to hybrid generation system.To realize the stable and smooth control on the battery energy storage system, on the one hand, the reliability of hybrid generation system is a must, and on the other hand, the safety performance and battery life are also demanded, this article carries out relevant work as follows:(1) Not only battery operating characteristics have been researched, but also the hybrid generation system architecture and grid index have been introduced. The control for inverter is modeled based on the principle of the vector control and Space Vector Pulse Width Modulation (SVPWM), and the basic control strategy for the battery energy storage system has been designed using the dynamic threshold in different operating modes.(2) In order to improve the system’s stability and the battery’s charge-discharge safety in low power, the optimization strategy control method based on the SOC is proposed concerning the poor result of the basic control in low state of charge. Besides, the effective critical-voltage and battery SOC value under low power control system has been analyzed, and a calculation method for charge-discharge current amplitude limit of the system stability control has been put forward.(3) Considering the jump problem while switching among operating modes under basic control, the flexible control strategy, to smooth the system’s controlling-current and controlling-voltage is put forward. Furthermore, a kind of calculation method for alternating current reference current instruction amplitude limit is proposed. The above researches ensure the quality of grid current and smooth control of battery’s current and voltage.Based on the above research works, the battery charge and discharge control system simulation model based on PSCAD is carried out. According the simulation results in different charge modes using basic control strategy, in low SOC using optimization strategy control method, and in mode switching depending on flexible control method, firstly the basic control strategy of battery energy storage system in this paper can maintain stability during normal modes, then the system’s stability is enhanced in the situation of the low SOC,and smoothed the control system at the mode switching.