Abstract:

A coordination strategy was proposed to smooth the tie-line power fluctuation of the combined heating and power integrated energy system (CMPIES) by using the virtual energy storage system. The structure and energy coupling mode of the CMPIES were analyzed. The controllable devices in CMPIES include micro-gas turbines, heat pumps, batteries and super capacitors. Virtual energy storage system is a thermal model based on utilizing the heat storage characteristics of building. Considering the controllable devices and the virtual energy storage system state index, weighted moving average filtering algorithm was used to optimize the tie-line reference power. The coordination strategy designs state map table to regulate the filter time constant based on the operation state of the controllable devices. The output of controllable devices is adjusted by the correction factor calculated by the state map table. The proposed strategy was validated by the field data from Green Energy University Laboratory in China. The simulation shows the strategy realizes the coupling and coordination between power and heat, ensures the power fluctuation smoothing effect and enhance the CMPIES control flexibility. At the same time, the comfort of the customers participating in the CMPIES can be maintained. The coordination strategy is able to enhance the penetration and consummation of distribution renewable energies and prolong the controllable devices' life.

Key words: combined heating and power integrated energy system(CMPIES), distributed energy resources, virtual energy storage, power fluctuation suppression