A Non-Parametric Approach to Harmonic Instability Mitigation for Renewable-Based Power Plants

IEEE International Symposium on Power Electronics for Distributed Generation Systems (PEDG), pp. 1–6

Abstract

In weak grid conditions, renewable-based power plants are under constant threat of harmonic instability. The detection of potential resonance between the grid side and converter side is critical, and furthermore, the synthesis of an adaptive virtual damping controller (VDC) is of utmost importance to mitigate potential harmonic instabilities. This work proposes a non-parametric stability monitoring tool to determine the critical frequency at which the impedance of the converter and grid side intersect and, furthermore, determine the range of frequencies where virtual damping is required. An adaptive VDC is proposed to shape the impedance of power converters. The main advantages of the proposed method are: (1) it requires minimal measurements; (2) it is adaptive yet simple in implementation; and (3) the damping design considers the identified critical frequency and bandwidth. Experimental validation of the proposed method is conducted using a rapid prototyping system. To demonstrate the impedance shaping characteristic of each parameter, the converter impedance is measured using a variety of control settings. Transient test cases were also included in the experimental evaluation to demonstrate the damping dynamics.

Authors 2

1. Sriram Karthik Gurumurthy Aachen Institute for Automation of Complex Power System

   RWTH Aachen University

   Affiliation as printed

   Institute for Automation of Complex Power System, RWTH Aachen University,Aachen,Germany

2. Antonello Monti Aachen Institute for Automation of Complex Power System

   RWTH Aachen University

   Affiliation as printed

   Institute for Automation of Complex Power System, RWTH Aachen University,Aachen,Germany