单相光伏接入的低压配电网平衡补偿技术研究

受非线性负载和单相负载等因素的影响，低压配电网自身存在较为严重的三相不平衡问题。随着低压配电网中单相光伏的大量接入，加剧了其三相不平衡度，造成变压器使用寿命降低、线路无功损耗增加等一系列问题。为解决单相光伏接入带来的三相不平衡问题，考虑配电网的三相不平衡因素及低压配电网的结构特点，本文研究一种基于瞬时无功理论的静止同步补偿器的平衡补偿技术。文中首先指出了单相光伏接入带来的三相不平衡问题；然后从理论上分析了静止同步补偿器的平衡补偿原理，并结合低压配电网的特点提出适用于接入低压配电网的静止同步补偿器控制策略，最后在PSCAD中搭建了仿真模型，仿真结果表明，所提补偿技术能够有效解决单相光伏接入带来的三相不平衡问题。

Research on Balance Compensation of Low-Voltage Distribution Network Bsaed on Single Phase Photovoltaic Access

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.