Study On Reserve Procurement And Pricing Considering Key Security Constraints

Security and economic operation plays an important role in power system operation. Under electricity market environment, power flow changes with market participants'bidding, resulting in more serious security problems. Static security assessment is the most common and important means for system security analysis, which only can provide the information whether operating point is located in a security state. This kind of binary information could not provide security margin of operation state to system operators.This thesis focuses on research of operation state security assessment based on quantitative analysis. Quantitative indicators for security assessment are put forward from the market and operation view, quantitative indicators are combined with operating reserve procurement and pricing under electricity market environment. Research contents are as follows:A method to calculate security margin of operation state is proposed based on optimal power flow sensitivities. Optimal power flow model is established based on minimizing operation cost, optimal power flow sensitivities is obtained by effective set of security constraints. On this basis, maximum loadability of initial operating state is established as an indicator of security margin. In a large number of security constraints, this indicator is corresponded to the key security constraints as system load increasing. According to the current operating point to the key security constrained, transmission bottlenecks and the corresponding safety margin can be calculated.Security pricing issues in electricity market environment for preventive control is analyzed based on operation states in both deterministic and probabilistic formulation. Optimal power flow with preventive control security constraints is constructed. Security pricing concept and its calculation method is carried on through analysis of Lagrange multipliers, which reflects the static security level for electricity market and nodal value for security control. In addition, we propose the application of preventive control pricing in demand side management and contingency evaluation.Operating reserve procurement and pricing method is put forward combined with security assessment indicators. Reserve participation factor is changed depending on different security margin; scheduling plan of operating reserve is formulated considering line flow overload. The value of reserve capacity is derived from security pricing and provides a theoretical basis for the settlement of reserve compensation scheme.