一类复杂输电网络改进的可靠性评估模型

Improved Reliability Evaluation Model for Complex Transmission Networks

含500kV／220kV电磁环网的大型输电网通常采用"一次电网环网,二次电网分区开环"的运行方式,以减小短路容量,提高电网的安全稳定性。这一类复杂输电网络的可靠性评估面临着计算量庞大、状态分析困难等问题。提出了一种改进的可靠性模型,用具有多状态的等值发电机和等值负荷来简化二次电网,并对最小切负荷量的线性规划模型进行修正。该模型既保留了二次电网对一次电网的支持作用,又有效地改善了计算效率,极大地缩短了评估时间。通过对实际的大型交直流混合输电网进行算例分析,验证了该模型的有效性及可行性。

In order to reduce short circuit capability and improve the security and stability, a bulk power transmission network with 500 kV/220 kV electromagnetic loop commonly operates with the primary loop closed and the secondary loop opened in sections. Reliability evaluation for those complex networks often encounters huge calculation tasks and difficulty of state analysis. An improved reliability evaluation model is presented to simplify each secondary sub-network by a multi-state equivalent generator model and an equivalent load model, and modify the linear planning model of minimum load curtailments at the same time. The proposed model not only preserves the backup effect on the secondary networks, but also effectively improves the efficiency and greatly shortens the CPU time. The feasibility and effectiveness of the proposed model has been proved by the test on a practical bulk AC/DC hybrid transmission network.