Abstract: As the penetration rate of photovoltaics increases, maintaining stable distribution grid voltages becomes more challenging, and it can also affect the power quality on the user side. This paper focuses on the study of a three-level power router in distribution grids with high photovoltaic penetration. The power router consists of three main components: a front-end rectifier, a DC busbar, and a back-end inverter, with the DC-DC converter directly connected to the DC busbar. The paper provides a detailed introduction to the topological structure and control strategy of the grid-side converter, and a series of simulation validations have been conducted to assess the device's reactive power support capability. The results confirm that the device can provide reactive power compensation to stabilize voltage fluctuations in the distribution grid.