Power Grids Control: Drivers and Trends

The energy transition objectives can�t be achieved without a massive integration of renewable energy sources into power grids. On one hand, this integration requires to reinforce large scale transmission system capacity, and interconnections between countries, in order to create an electricity market and the conditions for renewable energy trading. On another hand, conventional generation connected to the grid through synchronous generators is replaced by renewable generation which connected to the grid through power-electronics converters. This trend leads to three major changes for the grid: • HVDC transmission is becoming an important part of the grid • AC system inertia is reducing and system dynamics are modified • Grid-connected power electronics converters can be controlled in order to support grid operation The presentation will cover the following aspects of power grid controls: • The well-established principles of AC power system control • The principles of HVDC control, in a PtP link or in a multi-terminal system • The impact of AC system inertia reduction on power system stability • The contribution of Grid-connected power electronics converter to power system stability • The contribution of HVDC transmission to AC stability control Starting from the physics of the system, a selection of key control challenges will be explained, and some major evolutions in power grid control will be put into perspective.