Aggregation and Scheduling of Multi-Chiller HVAC Systems in Continuous-Time Stochastic Unit Commitment for Flexibility Enhancement
Lingling Le, Jiakun Fang, Xiaomeng Ai, Shichang Cui, Jinyu Wen
Abstract
Buildings, with their heating, ventilation, and air conditioning (HVAC) systems are the promising demand side resources for power grid to cope with the wind uncertainty. The challenge, however, is to ensure an efficient incorporation of large scale of HVACs into unit commitment to enhance the intra-hour flexibility for system operation. To this end, this paper focuses on the aggregation and scheduling of multi-chiller HVAC systems in continuous-time stochastic unit commitment. The continuous-time modeling method is utilized to handle the sub-hourly variability of wind power and the intra-hour flexibility of the HVAC systems. To describe the electricity consumption characteristic of the HVAC system with multiple chillers, a cooling model is formulated based on the chiller load sharing strategy and linearization method. Besides, an aggregation method for heterogeneous HVACs to provide reserve capacity is proposed to improve computational efficiency. Simulation results on the modified IEEE 118-test systems validate the effectiveness of the modeling and aggregation for multi-chiller HVAC systems, and demonstrate the benefits of applying the continuous-time HVAC reserve provision model to enhance the flexibility for the power system operation.