NR, as a world’s pioneering power system protection, automation and control manufacturer, has consigned products and and solutions to more than 90 countries and regions all over the world.NR believes that technology innovations make world wonderful and effective. Since establishment, we never stop researching new technologies and seeking better solutions for our customers. As a technology-oriented company, NR has owned many creative technologies and innovations included：DPFC (Deviation of Power Frequency Component) technology, Three-Defense-Line Solution; the world's first five terminal VSC-HVDC system, the world's highest voltage grade ±1100 kV UHVDC converter valve, the world's largest capacity of 3000 MW flexible DC converter valve, the world's first 535 kV high voltage direct current circuit breaker, the world's highest 500 kV voltage level unified power flow controller (UPFC).
According to the superposition principle, as to short circuit fault, post-fault current/ voltage can be decomposed into two parts when the power system has a short circuit fault. First part is the same current/ voltage value of pre-fault load state.
Based on the booming load of power grid, transmission lines expansion, the emergence of AC/DC grid, security and stability problem deliberately prominent. NR has developed a series of products based on ‘three– defense – line’ theory to prevent blackouts and even paralysis of major grid, to ensure the safe and stable operation of power system.
Zhoushan project is the world's first five-terminal VSC – HVDC transmission system. This project consists of five converter stations and the DC high-voltage transmission lines between stations which can realize a more resilient and quick transmission mode.
Unified power flow controller (UPFC) adapt power accurately for AC transmission lines, improving the controllability of transmission line, system stability and oscillation control capability, which can make full use of transmission capacity, reduce the overload, improve transmission efficient; economic and social benefits are significant.