With the rise of integration of renewable energy sources, existing electric power distribution networks are facing a variety of technical obstacles, one of which is modelling of the distribution networks for real-Time network monitoring and control. This research designs and analyzes a novel cyber-physical test system for real-Time reactive power compensation from smart inverters in the active distribution network using cyber-physical co-simulation between the Typhoon HIL and OpenDSS. The testbed is a two-layer system, with a physical and cybernetic layer. The physical layer is represented by Typhoon HIL 604 and the cybernetic layer is represented by software from Typhoon HIL, OpenDSS, and Python. The cybernetic layer is used to model, design, and control the reactive power from the smart inverter in real-Time. The distribution network considered is a CIGRE MV distribution network. Real-Time simulation results demonstrate the applicability of the proposed test platform in real-Time reactive power control.