The rapid growth of wind and PV power is increasing the utilization of existing grid infrastructure and intensifying the need for operational solutions that enable higher integration without immediate network reinforcement. In high-voltage distribution networks, energy control automatic (ECA) systems can increase available transfer capacity by allowing network resources normally reserved for contingency situations to be used already in normal operation, while maintaining secure system operation. This creates additional flexibility for integrating renewable generation, particularly during periods of high feed-in, but also introduces technical complexities regarding system behaviour under disturbances.

ECA relies on a central control unit and substation-based measurement and triggering devices that monitor network loading and initiate automated curative actions like disconnecting generation following fault-related events within milliseconds. Under operating conditions with high feed-in, such actions may alter power flows, reactive power balance, and voltage profiles in a dynamic manner. Since scenarios with high inverter-based generation are often associated with reduced system strength, it is essential to assess whether ECA operation may adversely affect transient voltage stability or lead to critical overvoltage phenomena.

This paper presents a dynamic simulation-based assessment of disturbance situations in realistic networks with ECA under scenarios of high wind generation. The study investigates the influence of varying generation and load conditions, different plant behaviour, reactive power provision, different triggering fault events and different curative response times on transient system voltages. The objective is to determine whether curative ECA actions introduce additional risks for dynamic voltage stability in renewable-dominated operating conditions especially regarding cascading tripping scenarios. The study is based on a high-voltage grid section of a German distribution grid.

The results show that, for the investigated scenarios, ECA operation does not lead to a significantly increased transient stability risk during disturbances beyond the risk of steady-state voltage stability considerations. While curative actions influence system response no critical additional transient overvoltages were observed. These findings support the secure use of ECA as an operational measure and provide a basis for evaluating dynamic performance in realistic power systems with high shares of converter-based renewable generation.