Modeling and Analysis of the Role of Energy Storage for Renewable Integration: Power Balancing
Modeling and Analysis of the Role of Energy Storage for Renewable Integration: Power Balancing
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DOI：
10.1109/tpwrs.2013.2266667
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发表时间：
2013-07
影响因子：
6.6
通讯作者：
Han-I Su;A. El Gamal
中科院分区：
文献类型：
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作者：
Han-I Su;A. El Gamal
可再生能源的高度可变性是其提高渗透率的主要障碍。储能有助于减少由于可用可再生电力与负载之间不匹配而导致的电力不平衡。存储可以在多大程度上减少这种功率不平衡？需要多少存储空间才能实现这一减少？本文提出了一个简单的分析模型，为这些问题提供了一些答案。考虑到多时间尺度的电网运行，我们将每个时间尺度的功率不平衡问题表述为无限水平随机控制问题，并表明贪心策略最小化剩余功率不平衡的平均幅度。从风电数据观察，在较短的时间尺度上，功率不平衡可以建模为独立同分布的零均值拉普拉斯分布过程，我们得到了最小成本和存储功率的平稳分布的封闭形式表达式。我们表明，功率不平衡的大部分减少可以通过相对较小的存储容量来实现。在较长的时间尺度上，功率不平衡的相关性不容忽视。因此，我们将独立同分布假设放宽为弱依赖平稳过程，并量化任意大存储容量的最小成本的限制。
The high variability of renewable energy is a major obstacle toward its increased penetration. Energy storage can help reduce the power imbalance due to the mismatch between the available renewable power and the load. How much can storage reduce this power imbalance? How much storage is needed to achieve this reduction? This paper presents a simple analytic model that leads to some answers to these questions. Considering the multitimescale grid operation, we formulate the power imbalance problem for each timescale as an infinite horizon stochastic control problem and show that a greedy policy minimizes the average magnitude of the residual power imbalance. Observing from the wind power data that in shorter timescales the power imbalance can be modeled as an iid zero-mean Laplace distributed process, we obtain closed form expressions for the minimum cost and the stationary distribution of the stored power. We show that most of the reduction in the power imbalance can be achieved with relatively small storage capacity. In longer timescales, the correlation in the power imbalance cannot be ignored. As such, we relax the iid assumption to a weakly dependent stationary process and quantify the limit on the minimum cost for arbitrarily large storage capacity.