Tie-line Power Smoothing Strategy of Integrated Energy System Using Separate Storage of Heat and Electricity

Abstract

The integrated energy system is an effective way to achieve efficient use of renewable energy and emission reduction. To solve the problem of large peak-valley difference and large instantaneous fluctuations of tie-line power connected with integrated energy system, this paper proposed a power smoothing strategy for the tie-line of the park’s integrated energy system. First, this paper proposed a power smoothing system combined with the of sensible heat storage and battery energy storage. Considering the difference in response speed and lifespan of heat storage equipment and battery energy storage system, an improved composite filtering method is proposed to realize the reasonable distribution of power smoothing components, which can avoid frequent charging and discharging of battery energy storage and improve power smoothing performance. Considering the change of user's heat demand, using fuzzy control to adjust the filter time constant in real time to ensure that the state of charge of the energy storage device is close to the initial value after the end of an operating cycle, which is helpful for the continuous operation of the system. Simulation analysis shows that the proposed strategy has a good tie-line power smoothing effect, which is beneficial to the efficient use of energy in the park's integrated energy system.