基于负荷曲线等效斜率提升光伏消纳能力的需求响应策略

Demand response assisted photovoltaic absorption strategy considering the ramp rate limitation

在高渗透率光伏电网系统中,针对由于爬坡率限制,火电机组无法应对由光伏发电功率减少引起的数小时级大规模功率失衡问题,通过削减光伏出力,降低净负荷曲线的峰谷差以维持功率平衡,但可能加剧电网中弃光现象。文章计及火电机组爬坡率限制,提出基于负荷曲线等效斜率的需求响应功率量化方法增加光伏消纳能力,并缓解由于光伏减少造成的电网功率不平衡。该方法首先分析了舒适度、动作次数等多种因素对需求响应聚合功率的影响;然后,根据负荷曲线等效斜率的计算方法,并提出超前调整法和动态因素调整法。超前调整法工作在日前时间尺度,转移峰值负荷至光伏资源充沛时段以增加光伏消纳能力;动态因素调整法工作在日内时间尺度,根据净负荷曲线的等效斜率量化计算需求响应功率并合理调整需求响应策略。最后通过算例仿真结果验证了所提方法的有效性。

In high permeability photovoltaic(PV)power grid,thermal power units may be unable to cope with the large-scale power imbalance caused by PV reduction due to the limitation of ramp rate.Reducing the PV output to reduce the gap between peak and valley of the net load curve to maintain the power balance may cause additional PV curtailment.A demand response(DR)quantification strategy based on the equivalent slope of the load curve considering thermal ramp rate limitation is proposed to increase PV absorption capacity and alleviate the power imbalance caused by PV reduction.First,the influence of comfort,action times and other factors on DR aggregation power is analyzed.Then the definition and calculation method of equivalent slope of load curve are put forward.DR quantization strategy based on equivalent slope is proposed,which includes leading adjustment and dynamic factor adjustment methods.Among them,leading adjustment works in day-ahead time scale to transfer the peak load to enhance the PV absorption capacity,and dynamic factor adjustment works in intra-day time scale to calculate the aggregate DR power according to the equivalent slope.Finally,simulation results verify the validity of the proposed strategy.