山东电力技术

低压配电台区一般位于配电网末梢，网架结构较为薄弱；且随着新能源比例的提高，系统惯量较低。模拟同步机的控制技术存在频率控制偏差大、难以即插即用、多台区互联控制实现复杂等问题。为此，提出基于卫星授时同步的高比例新能源配电台区自治控制方法。首先，分析基于卫星授时同步的配电台区的功率自治原理；其次，计及非线性及不平衡负荷，针对电流环控制参数导致的输出电压畸变问题，提出基于数字低通滤波器的改进控制算法；然后，在不依赖通信的条件下，通过检测及判断并网点电压相位及卫星授时同步角，提出台区自治/并网双模式下逆变器的柔性切换控制策略。此外，由于分布式电源工作于电流源模式，自治运行的配电台区间互联时不需要预同步，互联操作简单且暂态电流应力较小。最后，搭建包含四台分布式电源的物理实验平台，实验结果验证了所提方法的可行性及有效性。

Low-voltage distribution transformer supply zone is generally located at the end of distribution network,whose grid structure is relative weak.Along with the increasing proportion of renewable energy,the inertia of the system becomes lower.The control technology of analog synchronous machine has many problems,such as large frequency control deviation,difficulty in plug-and-play,and complex realization of interconnection control of multiple stations. An autonomous control of distribution transformer supply zone with high proportion of renewable energy was proposed based on satellite-time synchronization.Firstly,the power autonomy principle was analyzed.Then,considering nonlinear and unbalanced loads,an improved control algorithm based on digital low-pass filter was proposed to solve the output voltage distortion caused by current loop control parameters.Moreover,the voltage phase of the grid connection point and the synchronization angle of satellite timing were detected and judged without relying on communication,and the flexible switching control strategy of the inverter in the autonomous/grid connection dual mode was proposed.Due to the current-source characteristics,the interconnection of multi-stations is simple and cause a small transient current stress. Finally,the feasibility and effectiveness of the proposed method were verified by experimental results.