Practical Chart for Harmonic Resonance Assessment of DFIG-Based Wind Parks

Harmonic resonances in DFIG-based wind parks can be investigated by using extensive electromagnetic transient simulations, which is a time-consuming process. This paper shows that not all wind parks need such a detailed analysis. In response, the paper proposes a practical, easy-to-use method for a first-cut assessment of the risk of harmonic resonance of DFIG-based wind parks. First, simple equations are obtained to estimate resonance frequency and amplification in terms of wind park parameters readily available in practice. These equations reveal combinations of wind park parameters that cause problematic resonance. Such combinations are used to trace regions of concern in a chart. If the wind park is out of all regions of concern of the chart, one can directly declare this park is resonance-free, without running any simulation study. In addition to the analytic (model-based) method, a measurement-based method is provided for obtaining the resonance chart without running any simulation. Examples show how the proposed approach can be applied to facilitate resonance assessment during the wind park planning and operation.