Frequency stability in modern power systems with 100% renewable energy penetration

• Introduces a new approach to frequency stability in 100% renewable grids • Reduces renewable energy curtailment through strategic generator disconnection • Optimizes renewable energy integration without compromising grid reliability • Provides actionable insights for power system operators and policymakers The share of renewable energy sources (RES) contributing to electricity supply within power systems has notably increased. However, this development has been paralleled by a significant decline in both the capacity and quantity of synchronous generator units, resulting in a considerable decrease in the equivalent inertia of the power system. The reduction in inertia can significantly impact the frequency stability of the power system. This paper demonstrates that while some reduction in synchronous generator inertia is tolerable, excessive reduction due to high RES penetration can cause frequency instability. The study calculates the minimum requisite inertia for ensuring frequency stability and utilizes this value to establish a boundary stability line for the power system. A viable control strategy is proposed to safely navigate across this instability boundary and enhance frequency stability in a power system characterized by high penetration of RES generators. Simulation outcomes indicate that without an appropriate control strategy, the power system is prone to frequency fluctuations. The recommended approach entails disconnecting all remaining synchronous generators from the power system once the calculated threshold for minimum inertia reduction is reached. Consequently, it is advised that suitable controllers be employed within this proposed strategy to uphold frequency stability in a power system with substantial RES integration.