The phenomenon that upstream and downstream stations of cascade hydropower subordinate to different operators is widespread in China. When independently participating in spot market bidding

downstream stations with poor regulation

whose power generation is determined by upstream power stations

will face the problem of imbalance between bidding quantity and real quantity

resulting in difficulty of executing the transaction result

and which is detrimental to market stability and water resources utilization. Therefore

a day-ahead market clearing model with multi-operator cascade hydropower stations participating is proposed

in which

the downstream station is a price-taker with no need for declaring the power generation

and its bidding quantity is represented as a linear function about upstream station's bidding quantity. According to hydraulic coupling relationship of upstream and downstream stations

the linear function is embedded into the day-ahead clearing optimal model to realize joint clearing of upstream and downstream stations. The effect of water flow delay between upstream and downstream stations to downstream stations is mainly discussed and considered in the day-ahead market clearing process. Finally

taking a system with 6 generators and 8 electricity purchasers as an example

the bidding scenario of day-ahead power market is simulated. The result indicates that the imbalance of power generation faced by downstream station participating in power market independently can be alleviated by the proposed clearing model.