A Two-Stage Dispatching Method for Wind-Hydropower-Pumped Storage Integrated Power Systems

Abstract

With the fossil energy crisis and environmental pollution, wind energy and other renewable energy have been booming. However, the strong intermittence and volatility of wind power make difficult of its integration into grid. To solve this problem, this study proposes a complementary power generation model of wind-hydropower-pumped storage systems, which uses hydropower and pumped storage to adjust the fluctuation of wind power. How to consider the uncertainty and unpredictability of wind power output and make more reliable hydropower generation plan and pumped storage generation plan is the key problem to be solved in the grid with the high proportion of renewable energy. The martingale model of forecast evolution is used to describe the uncertainty evolution of wind power in different regions. According to the flexible load in the region, the flexibility index is used to quantify flexibility, and the transaction price is set to be proportional to flexibility. The two-stage framework of day-ahead and real-time dispatching model is then developed. In the day-ahead stage, different regions trade with each other. If the power after trading is imbalanced, it will be supplemented by hydropower and the grid to meet the power demand. In the real-time stage, the pumped storage is added to quickly balance the deviation of wind power and load between the real-time and day-ahead stages. Finally, considering the positive effect of hydropower on wind power consumption in the grid, a benefit allocation method based on improved Shapley value method is proposed. Test cases are simulated to verify the rationality of the proposed dispatching model and the benefit allocation method. After the cooperation of hydropower and pumped storage, the average revenue growth is 3.02%. The improved benefit allocation scheme makes more benefit of hydropower and pumped storage and promotes the cooperation of multi-participants.

Research on power trade potential and power balance between Lancang-Mekong countries and southern China under long-term operation simulation

“…The continuous, rapid, and uneven power demand growth and the rapid development of renewable energy sources have put forward higher requirements for achieving power balance in the regional unified power market. In order to achieve power balance and ensure regular regional power trading, this paper designs a calculation method for regional power balance and trading potential assessment, which not only gives the deterministic abandonment amount of wind power and photovoltaic power but also improves the accuracy of power balance analysis compared with the traditional power balance method (Hu et al, 2021), and provides a guarantee for regular trading in the power market (Zeng et al, 2017;Ji et al, 2021;Wang et al, 2021;Xu et al, 2022).…”

Solar Irradiance Nowcasting for Virtual Power Plants Using Multimodal Long Short-Term Memory Networks

“…A minority of research considers a shorter timeframe in which the photovoltaic generation nowcasting could be exploited. Recognizing the inevitable errors in predicting wind power generation day ahead, Hu et al (2021) propose a 2-stage dispatch, day-ahead and realtime, to exploit the more accurate short-term forecast; a similar approach is applicable to photovoltaic dispatch if short-term solar irradiation forecasts are available. Das et al (2021) propose to optimize photovoltaic generation and battery storage use in the context of hourly changing electricity prices.…”

“…Elkazaz et al (2020) consider a household with local photovoltaic generation and battery storage, and propose a scheme consisting of day-ahead optimization as well as real-time control to manage the errors caused to the optimization by uncertain forecasts. Elkazaz et al (2020), Das et al (2021), Hu et al (2021) are all examples of methods that use real-time measurements as the input to an algorithm that handles the error of medium-term renewable generation forecasts, so an obvious line of further research would be to exploit nowcasting. Nefedov et al (2018) exploit electric vehicle batteries for short-term storage of surplus photovoltaic energy, updating plans as vehicles arrive or if they leave unexpectedly.…”

Optimal Electricity Allocation Model Under China's Planning-Market Double-Track Mechanism Considering Bidding Game of Generation Companies

“…The equivalent load duration curve after deduction of the imported energy and priority generation energy is shown in Figure 3. Due to limitation in reservoir capacity and unit rated power, power and energy constraints of hydropower and pumped storage plants can be expressed as (Hu et al, 2021). where P H (s, t) and P P (s, t) represent the output of hydropower plant and pumped storage plant, respectively, in period t under scenario s. P max At present, the power market in China is similar to the pool mode, and there is no awareness in market bidding on the demand side.…”