MPC Coordinated Primary Frequency Support of Small- and Large-Scale Heat Pumps

Heat pumps (HPs) can provide flexibility for different power system services, including frequency support. The modern power system integrates various sized HPs as part of individual or district heating systems. While the basic principles and layout are similar for differently sized HPs, differences in dynamic response characteristics entail different limitations on their participation in grid service provision. Small-scale HPs (S-HPs) have a fast response and are widely distributed, while large-scale HPs (L-HPs) are more centralized with slow dynamics. This paper propose an innovative and coordinated control scheme for primary frequency response from S-HPs and L-HPs. The method configures the control of S-HPs based on an observed homogeneous S-HP population response to control actions. Furthermore, a centralized optimization of L-HPs based on model predictive control (MPC), balances the S-HP population’s response. Analysis of simulation results evaluates and compares the proposed methodology against exiting methods that consider only S-HP units. Results show the significant improvement of the frequency nadir with the support from the heating system through the proposed method.