Improved Eigenvalue Sensitivity Method for Designing Power System Damping Controllers

Abstract

Inter-area oscillations are a major challenge for power systems, as they can lead to system instability if they are not damped. To prevent such, restrictions on power transmission over specific lines are often necessary, which in turn incur significant economic costs. This justifies the need to improve the tuning of Power Oscillation Damping Controllers (PODs). PODs can be implemented in synchronous generators, FACTS devices, HVDC links, and BESSs.Lead-lag controllers are widely used in the industry for their simplicity and effectiveness. The eigenvalue sensitivity method applied to the tuning of lead-lag controllers, enables direct determination of controller parameters, making the method particularly efficient for practical applications.With the eigenvalue sensitivity method, the trajectory of the eigenvalue is assumed to be linear and defined by the sensitivity calculated for the initial position of the eigenvalue. However, the eigenvalue trajectory is not necessarily linear and may deviate from the sensitivity, especially in the case of high gain values.In response to these limitations, this work introduces two approaches to optimize both the gain and the structure of a POD tuned using the sensitivity method. A well-known study case is used to illustrate the sensitivity method's limitations and the proposed solutions' effectiveness.