Opinion on intra-provincial medium and long-term electricity market considering available transmission capacity

In 2021, China proposed to promote the construction of the medium and long-term (M-L) electricity market and accelerate the construction of the national unified electricity market (Huang and Li, 2022). Each province had also issued M-L electricity market trading rules. M-L electricity market refers to the multi-year, annual, quarterly, monthly, weekly and multi-day electricity wholesale transactions carried out by power generation companies, power consumers, electric power companies, and other market entities through the negotiated transaction, centralized auction transactions, and other market-oriented methods. At present, the M-L electricity market in various provinces in China mainly carries out electrical energy transactions. The organization forms of the transaction include auction transactions and negotiated transactions. However, various organization forms are generally not considering network constraints during market clearing (Guo et al., 2020). This can lead to a series of problems, such as the power dispatching institution having to take a long time to do the security assessment, and the time of transaction organizations being longer. Moreover, the adjustment rate of the first market clearing result is relatively high because network constraints are not considered and the security assessment time is long (Xia et al., 2020). Due to the uncertainty of new energy, the market needs to provide sufficient adjustment opportunities, so the M-L market must have the ability to start the market periodically. But a high adjustment can make it difficult for the M-L market to carry out full-cycle and high-frequency transactions. The demand for normalized transactions in the M-L market cannot be met. Therefore, to take high-frequency transactions and security assessment into account in the market, it is necessary to consider the network’s available transfer capability (ATC) constraints in M-L electricity transactions.