An Online Adaptive Damping Controller for Converter-Interfaced Generation

Abstract

The increasing integration of converter-interfaced generation within large-scale synchronous power systems is presenting both new challenges and opportunities in how we operate these dynamical networks. One of these challenges is designing and parameterizing the digital control loops that dictate the dynamical behavior of these fast-acting resources. Improperly tuned gains, or unexpected controller couplings through the network, can lead to poorly damped oscillations during disturbance conditions and/or decrease the system stability margin. Within this work, we present an approach for adaptively tuning a damping controller to improve the dynamic response of converter-interfaced generation, based only on local measurements. We show that, with low-amplitude probing, we can identify a subset set of observable system modes. We then propose a linear MISO state-feedback controller to improve the damping ratio and stability margin of the system. We show the effectiveness of the proposed controller through both eigenvalue analysis and time-domain simulations. We first demonstrate the proposed approach on a simple 3-bus system followed by a larger test case, the IEEE 14 bus system, with multiple devices simultaneously probing the network.