Compact controllable high-voltage power lines (HVPLs) are a new generation of alternating current power transmission lines, representing the newest achievements in the field of power transmission and control means, new technical solutions for the design, insulation, connection layouts and control systems. The main distinctive features of the compact controllable HVPLs are: extremely reduced phase-to-phase distances adopted relative to the minimal required insulation distances (dielectric strength of the phase-to-phase gaps) at a maximum operating voltage and also under lightning and commutation overvoltage; new phase configurations, where tower’s grounded parts (poles, cross-arms, suspension hubs) placed outside of the interphase space; insulating elements (insulating spacers or screeds) between closely adjacent HVPL phases installation if required, fixing the selected distance between phases and dampening conductor’s vibration or galloping under severe weather conditions, which ensures high mechanical stability and reliability of the adjacent phases in spans; angular phase shifts establishment between the voltage vectors applied to the compact controllable HVPL adjacent phases; implementation of high-speed phase control devices and adjustable compensation devices (FACTS type). Compared to the conventional high-voltage power lines, compact controllable ones with FACTS devices ensure the following: 1.2-1.6 times increase in throughput; reduction of total costs per transmission capacity unit by 20 – 30%; 1.5-2 times alienated land reduction in case of equal power transmission; reduction of electric field intensity in the HVPL external space, and, hence, mitigation in the environmental effect; ability to control power flows and their directions; and total energy losses reduction in the power system.