Research On Transfer Capability And Transaction Scheduling Of Energy And Ancillary Services In Electricity Markets

This thesis presents the application of electricity market theory, power system analysis theory and microeconomic theory combined with the optimal power flow(OPF) and the continuation power flow(CPF) methods to the following issues emerging in the blooming electricity market: available transfer capability(ATC), market settlement rules, bid and auction mechanism and the operation of reserve capacity. The main achievements are as follows:An OPF-based ATC calculation model involved the impact of branch outage contingency on system's voltage stability was set up. The existing transaction in the electricity market was considered and the generalized parameterization power flow equations and corresponding inequality constraints under branch outage contingency was included in the OPF model. Contingency selection was performed through sensitivity indices between branch flows and the system loading margin. Finally, ATC with static voltage stability constraints was calculated by primal-dual interior point methods.The producer surplus theory and consumer surplus theory were applied to deduce the cross subsidies among market participants in electricity pool under double auction mechanism, when market-wide system marginal price (SMP) was used as settlement rule. We pointed out that the physical constraints which maintain the normal operation of power systems such as transmission grid resistance, bus voltage level and transmission capacity etc., can not be ignored when conducting market analysis and hence, the electricity market is an uncompetitive one. The SMP based market clearing mechanism will result in inefficiency. Based on IEEE 30-bus system, different market efficiencies were compared under the SMP and locational marginal price (LMP) obtained from OPF. Results show that using LMP as market settlement rule can prevent from the cross subsidies and improve market efficiency, which favours rational electric power production and consumptionThe power variation on the consumer side and the generation side caused by double auction may result in power flow's redispatching and has disadvantageous effects on power system security operation. The transaction model including bilateral contracts and double auctions with voltage stability margin constraints was set up in this thesis. CPF and OPF were combined to detect the transmission network's vulnerablespots and make reasonable transaction scheduling. The proposed method can achieve the reliable operation of the power system and maximize the social welfare.To deal with the dilemma between the limited generation capacity and certain reserve capacity requirements, an energy and reserve joint dispatch OPF model was proposed based on the idea that customers can play an important role in the load management and take active measures to provide reserve capacity for the power system. The electricity market operation benefits were studied when the customers were involved in the reserve capacity market if the market is open to both supply and demand sides. The results of IEEE 30-bus system show that the system benefits are improved and payoff for the reserve capacity is reduced with a fall both in the locational marginal price and the system marginal reserve price when the customers entered into the reserve market and became new suppliers for reserve capacity.