Research On The Bi-level Optimization Of Energy And Reserve Markets And The Balancing Option Dealing For Wind Power Seller

Under the double pressure from CO2 emission reduction and fossil fuel shortage,wind power exploitation is becoming an effective option to resolve the conflict between energy supply and environment protection.However,the randomness of wind power has imposed great risk on the secure and economic operation of power system.Thus,in order to ensure the accommodation of wind power and coordinate the security,economy and eco characteristics of power system,it is necessary to research on aspects of both system dispatching and market dealing to encourage more parties of coal-fired power and wind power to engage in ancillary service.By reviewing previous studies on wind accommodation,mathematical descriptions of optimal models with stochastic variables,such as wind output and marketing prices,are introduced;then,wind power accommodation models with various regulating resources are summarized;next,the impact from power marketing principles on the wind power accommodation is concluded.Particularly,scenario analysis for stochastic variables process,and conditional value at risk(CVaR)and option contract for risk control are stated in detail.Power system's economy can be impaired with a large-scale integration of wind power,occupying too much spinning reserve.To tackle this problem,the relationship between energy market and ancillary market is analyzed first,and then,a bi-level stochastic optimal model is proposed from the perspective of independent system operator(ISO)to balance the benefit from both markets.This optimal model takes the minimum generation cost and reserve cost as the upper and lower object respectively.The availability and probability of wind power are considered in the upper level in form of chance constraint,aiming to optimize the output in energy market.In addition,CVaR is introduced to lower level to measure the risk of load loss and wind curtailment,targeting at optimizing the allocation of spinning reserve.The case study validates the effectiveness of proposed model under various availability and probability constraints of wind power and their confident levels.Also,proposed bi-level model shows greater performance in system's economy than normal single-level model does.To lower the risk of the fluctuation of regulating prices faced by wind power supplier,option contract is adopted in the ancillary market.The pattern of option dealing for regulating service is discussed and the decision model for regulating option is established from the perspective of wind power supplier.With this decision model,quantities of option purchase can be determined with historical information so as to lock in the regulating price;and quantities of option redeem can be determined with intra-day information so as to release the excess spinning reserve occupied a day ahead.The case study indicates that the proposed decision model can reduce the cost of regulation when the deviation between declared output and actual output as well as the difference between day-ahead spot price and real-time regulating price is significant.In the context of the rapid development of renewable energy,proposed bi-level optimal model can coordinate the benefit from both energy and ancillary market,reduce both fuel and reserve cost of the whole system,and facilitate the accommodation of more wind power.The effect of proposed model can be adjusted by tuning the parameter based on historical operation experience.In addition,when the regulating resources become rare and the fluctuation of regulating price is severe,option contract can help wind power suppliers to avoid risk from regulating market and facilitate the development of wind power industry.