1.State Key Laboratory of Power Transmission Equipment & System Security and New Technology (Chongqing University), Chongqing 400044, China;2.State Grid Chongqing Electric Power Research Institute, Chongqing 401123, China

The random volatility of renewable energy has made the influence of automatic generation control (AGC) actions of units on the system operation increasingly prominent. The existing stochastic optimal economic dispatch methods are difficult to account for the actual response actions of AGC units on fine-grained timescales during the dispatch periods, seriously threatening the safe operation of the power grid. Therefore, this paper proposes a chance-constrained economic dispatch method explicitly considering response actions of AGC units on fine-grained timescales. First, the response model of AGC units on fine-grained timescales considering the uncertainty of net load is constructed. Based on the actual response strategy of AGC, a response mode of AGC units to net load fluctuations and their uncertainties is constructed under the chance-constrained framework, achieving accurate modeling of AGC unit response actions on fine-grained timescales. Then,a chance-constrained economic dispatch method embedded with AGC unit response models on fine-grained timescales is proposed, which considers the response actions of AGC units on fine-grained timescales in the chance-constrained economic dispatch model. Finally, the proposed chance-constrained economic dispatch model is reformulated in an analytical form, achieving an explicit characterization of the response actions of AGC units on fine-grained timescales. The proposed modeling method is not limited to the chance-constrained optimization and can also be applied to stochastic optimization methods such as multi-scenario and robust optimization. The case analysis shows that the proposed method provides a more economical and secure dispatch scheme compared with existing chance-constrained economic dispatch methods.