Secondary voltage control in the Netherlands

Abstract

Increasing integration of renewable energy sources, distributed generation, smart grid technologies and other power electronic devices into the grid has given rise to numerous challenges in the electricity transmission and distribution system operations domain. Due to the increasing complexity in electricity market processes, control of active power in steady state time frame is becoming infeasible to system operators at normal state of operation. Whereas, steady state control of reactive power is still viable to system operators. System operators control reactive power resources in steady state time frame to maintain a good voltage profile within their power system. Currently, this steady state voltage control is performed manually for the Dutch transmission system by control engineers with minimum real-time computational assistance or no intelligent decision making tool. This master thesis focuses on the feasibility study conducted for employing an intelligent control system that can be used for secondary (or steady state) voltage control scheme in the Dutch transmission system. The feasibility study included literature reviews on hierarchical voltage control schemes of other European transmission systems, the approach of secondary voltage control in the national control center and several artificial intelligence techniques available for coordinated voltage control. In this study, a rule based controller was developed to initialize a reactive power optimization problem (with multiple objectives) for a mixed integer linear programming solver. Rule based controller was preferred mainly due to its simplicity, adaptability and ease of mapping expertise of control engineers (& requirements of transmission system operators) as rules. Simulation based studies were performed using this controller on an 80-bus test system and snapshot scenarios of the Dutch transmission system after defining multiple areas within them.’