【摘要】 随着农村配电网用电需求的增大，线路末端容易发生较大的电压降落，造成随负荷变化周期出现的低电压问题，影响偏远地区居民的正常用电，且传统的改造方式成本较大，为此，从经济性角度出发，本文拟用原有配电线路构建直流供电路径，通过模块化变流器组和开关网络的配合，形成低压配电网的交直流切换供电系统，实现在末端电压满足要求的轻载情况下采用交流配电方式，从而减少不必要的损耗，提高供电效率；在末端出现电压偏低问题的重载情况下切换至直流配电方式，通过电力电子变换装置提高末端用户的电压合格率。该方案设计了满足切换要求的开关网络逻辑时序，依靠检测切换过程中线路相关电气量的变化规律调整两侧距离较长的开关网络和变流器组的运行状态，从而避免了远距离通信交互。仿真和实验结果验证了该方案的可行性。更多还原

【Abstract】 With the increase in electricity demand in rural distribution networks, large voltage drops are prone to occur at the end of the line, causing low voltage problems that occur with the cycle of load changes, affecting the normal electricity use of residents in remote areas. The traditional line modification method is costly. Therefore, from an economic point of view, this article intends to use the original power supply line to construct a DC power supply path. Through the cooperation of the modular converter group and the switch network, the AC and DC of the low-voltage distribution network are formed: The power supply system is switched to realize the AC power distribution mode at light load and qualified terminal voltage to improve power supply efficiency; and is switched to the DC power distribution mode at heavy load and low terminal voltage to improve the terminal user voltage qualification rate. This method designs a set of reasonable switch network switching logic sequence, and adjusts the operation status of the remote switch network and converter group on both sides by detecting the voltage and current changes of the line during the switching process, thereby avoiding remote communication interaction. Simulation and experimental results verify the feasibility of the method.更多还原