The unprecedented operational complexity and security risks in operating the Chinese UHV AC/DC power grid calls for a new generation of real-time (sec-order) online analysis systems to provide decision support. Our recent Digital Twin based online analysis research and development work to address the needs is presented. In addition

a high-level solution architecture for the future real-time online analysis systems is proposed for realizing: a) The delay of the virtual model to mirror the physical power grid is in sub-sec range; b) The downstream online analysis applications could have sec-order responsiveness.