Sensitivity factors in electricity-heating integrated energy systems

Abstract

In integrated energy systems, adjusting the energy conversion of a coupling unit changes the power flow in the connected energy systems. Also, it forces other units to adapt their generation to keep the energy balance in the energy systems. The impact on the power flow and the complexity of the interaction between single networks will increase the more coupling units are installed. The impact on the power flow can be determined by power flow calculation and optimization algorithms. However, to analyze the impact of a unit’s power change on all state variables, the available methods need to solve a second power flow or optimization. This is computationally effortful and time-consuming. Hence, this paper proposes a method that estimates such a change easily and quickly. The method extends the widely used approach of sensitivity factors in electric power system analysis to electricity-heating integrated energy systems. The sensitivity factors are derived in a straightforward way by linearization using the Jacobian matrix of a coupled power flow calculation before the change. These new sensitivity factors can precisely estimate the impact of a change on the energy system’s power flow and reduce the calculation time of new setpoints by factor eight on average.