UPFC/BESS接入大电网新能源系统的功率平衡跟踪控制

Power Balance Tracking Control of UPFC/BESS Access to New Energy System of Large Power Grid

随着大规模新能源发电并网、大容量高效变流器等新技术的相继涌现,能源供需广域平衡对柔性交流输电技术提出了新的要求。为了解决波动性和间歇性新能源电力的消纳并网问题,平衡源、荷功率波动,增强系统稳定性和输电能力,提出一种新型的基于蓄电池储能系统(batteryenergy storage system,BESS)接入统一潮流控制器(unified power flow controller,UPFC)的装置UPFC/BESS。通过建立大电网新能源系统的数学模型和设计UPFC/BESS功率的短时平衡、中长期峰谷、陡升陡降控制策略的方法,得出UPFC/BESS能够在最严重功率失衡情况下动态平衡新能源系统有功和无功功率的结论。基于PSCAD/EMTDC平台搭建了含新型UPFC/BESS装置的仿真模型,仿真结果表明UPFC/BESS具有较强的有功调节和平衡能力,能快速调节源、荷的功率失衡,较好地平衡新能源电力的功率波动,对增强大电网功率安全裕度和降低电源备用容量的投资具有重要的意义。

With the successive emergence of such new technology as large-scale new energy power generation and large power and efficiency inverter etc.,the requirement of wide area balance of power supply and demand to the flexible AC transmission technology is proposed. For solving the issue of eliminating grid connection of fluctuating and intermittent new power,balance source,power fluctuation of load and increasing system stability and power transmission capability,a new type of FACTS named UPFC/BESS is proposed on the basis of unified power flow controller（UPFC） and battery energy storage system（BESS）. The dynamically balancing both active and reactive power of new energy by UPFC/BESS in case of most critical power imbalance is obtained by way of setting up mathematical model of the new power system of big grid and designing such strategy of short time balance,intermediate and long term peak valley,abrupt rise and reduction control. The simulation model including UPFC/BESS device is set up based on PSCAD/EMTDC platform. It is shown by the simulation result that UPFC/BESS has strong active power adjustment and balance capability,can adjust quickly power imbalance of load and power,can balance power fluctuation of new power and has importance significance in strengthening safe margin of high power grid and reducing investment of back up capacity of power supply.