Abstract:Affected by factors such as non-linear load and single-phase load, the low-voltage distribution network itself has a serious three-phase imbalance problem. With the large-scale access of single-phase photovoltaics in the low-voltage distribution network, its three-phase unbalance degree is aggravated, resulting in a series of problems such as reduced transformer service life and increased line reactive loss. In order to solve the three-phase unbalance problem caused by single-phase photovoltaic access, considering the three-phase unbalanced factors of distribution network and the structural characteristics of low-voltage distribution network, this paper studies a balanced compensation technology of static synchronous compensator based on instantaneous reactive power theory. Firstly, this paper points out the three-phase unbalance problem caused by single-phase photovoltaic access, then analyzes the principle of static synchronous compensator in theory, and puts forward the control strategy of static synchronous compensator suitable for low-voltage distribution network according to the characteristics of low-voltage distribution network. Finally, a simulation model is built in PSCAD to simulate. The results show that the proposed compensation technology can effectively solve the three-phase unbalance problem caused by single-phase photovoltaic access.