Harmonic resonance mode analysis in dq domain

Harmonic Resonance Mode Analysis (HRMA) is a technique developed to study harmonic resonance in a power system. Compared to conventional resonance analysis techniques, HRMA is a powerful method that can indicate the origin and the locations most affected by a given mode of resonance. The method has been shown to be effective for large scale resonance studies. However, very simplified models are used for representing power converters. With the proliferation of power converter interfaced energy sources in the future power system, there is a need to correctly model power converters in such studies. The main challenge is to correctly represent the control loops. The controllers are mostly designed in dq domain while the study is performed in phase domain. To address this problem, this paper proposes extension of HRMA to dq domain. Formulation of the problem in dq domain is presented in detail followed by verification using simple test cases. A detailed model of a voltage source converter for the aforementioned analysis is also developed and analysed using the test cases.