Research And Application Of Medium-long Term Power Trade Check Technology In Power Market

With the development of electricity markets,the electric quantity of medium and long-term transaction gradually replace the annual plan.The imbalance of power generation and uncertainty of transaction result in the decrease of power grid security margin.The coupling characteristics of the power grid are prominent,and the operation mode of the power grid is complex.The trans provincial market and the intra provincial market are bordered by each other,and the stability limits are mutually constrained.On account of above reasons,the security check of medium and long-term transaction based on artificial experience is difficult to meet the requirements of refinement.In this thesis,the security check technology of the medium and long-term transaction is studied based on the demand of generation dispatching in the electricity market.Firstly,it is difficult to consider the security constraints of power grid in the market environment,and the transaction results reduce the schedulable space of the dispatching organization.In view of the above problems,this thesis proposes a security check method to calculate the electricity quantity limit of related entities.This method obtains the maximum trading space of each dimension of the grid by calculating the limit of tradable power of each entity,thus providing a safety boundary for medium and long-term transaction.Secondly,in order to quantitatively evaluate the potential security risks of medium and long-term electricity transaction to power grid and solve the problem of limited factor positioning and adjustment in the execution of electricity contract,the medium and long-term transaction security check model based on the security constrained unit commitment(SCUC)is proposed.The two-stage optimization method of decoupling between electricity quantity check and electricity quantity correction is used to improve the refinement level of security check and reduce the difficulty of solving.On this basis,an algorithm based on model dimensionality reduction is proposed for solving medium and long term unit commitment.Through a series of model dimensionality reduction strategies such as similar period merging,invalid start and stop variable identification and effective safety constraint identification,the state space and constraint matrix space of SCUC optimization problem are reduced,and the efficiency of optimization problem solving is improved.This thesis is of great value to ensure the safe operation of the power grid and reliable power supply in the medium and long term under the electricity market environment,thus the market organizers can grasp the feasible boundary of the medium and long term transaction,which provides technical support for the formulation,adjustment and guidance of basic electricity transactions and contracts,and improves the level of analysis and decision-making of power grid in the medium and long-term transaction.