Damping Control Loops for Mitigating Power System Oscillation with Wind Parks Support

Abstract

The intermittency of power generation from Wind Parks can trigger electromechanical oscillations among interconnected synchronous generators. In a stressed electrical system, such oscillations can be lightly damped and lead to rotor angle instability. Therefore, investigation in oscillation damping is required. To date, many publications proposed damping control strategies for Wind Parks and synchronous generators. Few investigated the influence of control signal types and installation sites for the case of renewable integration. Therefore, primary contributions of this dissertation are on analyzing the influence of control signals and installation site of Damping Control Loop (DCL) in the event of high wind penetration. Firstly, investigations on the use of rotor speed and active power deviations as control inputs were studied. Secondly, the influence of DCL installation sites were evaluated. Investigations were conducted using a simulated electrical grid consisting of one hydro synchronous generator and a Wind Park. The designed DCL was based on a proportional-integral (PI) controller. The impact of control input was examined using rotor speed and active power deviations. To assess the impact of the installed damping location, DCL was implemented separately in the synchronous generator and Wind Park as well as in both generation plants. In addition, time delays were introduced in the case of using active power deviations as the control input. The simulated system was subjected to symmetrical and asymmetrical faults. According to the obtained results, using active power deviations provide better damping performance. The damping capability of the system was further improved when DCLs were installed in both the hydro synchronous generator and Wind Park. The maximum critical clearing time was also extended when compared to no damping control. To conclude, this dissertation recommends that DCL should be installed in Wind Parks even when the neighboring synchronous generators are equipped with damping controllers. In addition, the use of active power deviations is preferred as the control inputs.

Date of Award	Dec 2014
Original language	American English
Supervisor	Jimmy Peng (Supervisor)