ATC Calculation With Transient Stability Constraints For AC/DC Transmission Systems

Due to the complexity and the necessity of considering transient stability in the AC/DC Transmission Systems ATC calculation, this paper proposed a practical approach on available transfer capability (ATC) calculation for the AC/DC systems taking transient stability into account. Power System Analysis Software Package (PSASP) was used as a built-in calculation platform, VC++was used to write calculation process and the repetitive power flow method was used to calculate ATC model. The example of EPRI-36Power System verified that the proposed method could be used to calculate and analyze ATC of practical AC/DC hybrid power systems and easy to be programmed. Calculation and simulation results indicated that the proposed practical method could consider Static and transient stability constraints involved in ATC calculation for AC/DC transmission systems, coordinated economy and security of power system, meanwhile the method had good functionality.Load increasing means total losses may increase as well. However, different power allocation scheme brings about different total losses. By adding node incremental loss modifying factor to change the original power flow distribution method, this paper proposed a power allocation scheme which can effectively reduce loss increments in the process of load increasing. The example of EPRI-36Power System verified that the proposed method is correct and effective.Based on the previous theoretical studies, ATC calculation and analysis software for Shandong Power system is developed, providing decision and suppor tools for system planning and operation. Taking Ningdong DC system as the main study object, this paper has done some simulation analysis of the mutual influence between AC and DC systems under different failure modes, meanwhile, the impact of DC system on ATC of Shandong Power system is also calculated and analysis. The research has theoretical and practical guiding significances for the AC/DC transmission system planning and reliable operation with a broad application prospect.