Improving power system damping using a combination of optimal control theory and differential evolution algorithm.

Area of Science:

• Electrical Engineering
• Control Systems Engineering
• Power Systems Analysis

Background:

• Sub-synchronous oscillations (SSO) pose a significant threat to power system stability.
• Existing control strategies often struggle to provide robust damping for these oscillations.

Purpose of the Study:

• To develop and validate a novel control strategy for improving the damping of sub-synchronous oscillations.
• To enhance power system stability and reduce fluctuations through optimal controller tuning.

Main Methods:

• A coordinated control strategy involving Linear Quadratic Regulator (LQR), Power System Stabilizer (PSS), and Thyristor-Controlled Series Capacitors (TCSC).
• Formulation of the control problem as an optimal linear regulator problem.
• Optimization of control parameters using the Differential Evolution (DE) algorithm.

Main Results:

• The proposed LQR-based strategy demonstrated superior performance in damping sub-synchronous oscillations compared to conventional methods.
• Case studies on a typical generator confirmed the effectiveness and quick response of the proposed method.
• The coordinated control approach provided robust stability and optimized the system performance index.

Conclusions:

• The novel LQR-based control strategy offers an effective solution for damping sub-synchronous oscillations.
• Coordination of LQR with PSS and TCSC ensures robust stability and improved power system performance.
• The LQR controller's flexibility and usability enhance its applicability in managing power system oscillations.