Coordinated Control Strategy of Load Virtual Energy Storage System for Improving Stochastic Power Absorption in Distribution Network

The randomness and volatility of stochastic power source such as PV and wind change the voltage, current and supply-demand of distribution network, thus affecting power absorption, safety and stability. This paper presents a new coordinated control strategy of load virtual energy storage system (LVESS), which is capable of improving stochastic power absorption in distribution network. First, the aggregation characteristics of typical temperature control loads (TCLs) which have good energy storage characteristics, such as air conditioners, refrigerators etc are studied and the aggregated power control models are established based on different characteristics. Refer to the state of charged of battery energy storage, the virtual state of charge (VSOC) and adjustable power which are used to describe and tag the regulation ability of LVESS are evaluated considering user comfort, load control signal and operation state. According to the model and VSOC, a two-level optimized coordination control strategy which takes into account both technical indexes of distribution network and user electricity costs is put forward. The strategy is verified to realize power coordination control and resolve the problems brought by stochastic power source.