发电系统充裕度与灵活性的随机评估

Stochastic Assessment of Adequacy and Flexibility of Power Generation Systems

在含可再生能源的电力系统中,发电容量的灵活性会影响系统的可靠性和可再生能源的消纳,传统的发电容量充裕度指标无法全面反映含可再生能源电力系统的发电容量可靠性。为此,首先提出了电力系统向上/下发电容量不足指标,用于综合描述电力系统的发电容量充裕度和灵活性。其次,采用随机生产模拟技术,给出了向上/下发电容量不足指标的随机评估方法,其中考虑了发电机组的随机强迫停运、最大/小技术出力限制以及不同出力状态下的向上/下爬坡速度,并可适用任意时间尺度下的时序负荷,从而反映了发电机组受负荷需求影响导致的爬坡容量不确定性和由其本身强迫停运导致的不确定性。最后,通过算例分析验证了所提指标和方法的有效性,并定量研究了风电接入比例、时间尺度等因素对向上/下发电容量不足指标的影响。

In the power systems with renewable energy penetration, reliability of power systems and their capability of accommodating renewable energy are significantly affected by generation capacity flexibility. However, traditional generation capacity adequacy indexes cannot fully describe generation capacity reliability of these power systems. For this purpose, four indexes are defined to describe the generation capacity adequacy and flexibility, namely the up/downward capacity shortage probabilities, expected up/downward capacity shortages. Then, a stochastic assessment method of the proposed indexes are developed using probabilistic production simulation technology and applied to different time scales of chronological load. In this model, the forced outage and the maximum/minimum outputs of generation units are considered, and the up/downward ramp rates in different generation output ranges are taken into account. Thus the uncertainty of ramp rates caused by load demand and the uncertainty caused by random forced outage can be reflected. Numerical examples are presented to verify effectiveness of the proposed indexes and method. In addition, the quantitative studies on the influence of wind integration scale and time scale on the up/downward generation capacity shortage indexes are presented.