This paper presents the development and validation of an accurate and computationally efficient wideband reduced-order dynamic equivalent model for the Type-3-based wind power plant (WPP). The proposed Type-3 WPP equivalent model reproduces the dynamic behavior of the WPP in response to an electromagnetic transient in the host power system and is composed of two parts: 1) a static frequency-dependent network equivalent model which represents the response of all passive components of the WPP in a wideband frequency range, and 2) a dynamic low-frequency equivalent model that represents the aggregated dynamic model of the doubly-fed asynchronous generator (which is also referred to as doubly-fed induction generator) wind turbine generators, their local controls, and the WPP supervisory control. The proposed model significantly reduces the hardware/software computational burden and the computation time, as compared to the WPP detailed models, without compromising the accuracy of the simulation results. The proposed model is incorporated as a software module in the PSCAD/EMTDC environment and its computational efficiency and accuracy are verified based on comparing the results with those of a detailed model.

This paper reviews and applies the balanced realization (BR) theory to obtain reduced-order models from dynamic system equivalents of electric power networks. BR allows obtaining reduced-order models via a process in which the original asymptotic stable system is internally balanced. The balanced system is truncated according to its dominant dynamics. It can be proven that the truncated, that is, reduced-order, system is also stable. This paper applies the BR method to dynamic system equivalents represented as frequency-dependent network equivalents (FDNEs). Furthermore, it shows that an assumed reduced-order FDNE can be further reduced via the BR process. Four case studies, involving one transmission network and three wind power plants, are presented.

This paper introduces an accurate and computationally efficient reduced-order dynamic equivalent of a Type-4-based wind power plant (WPP) for the analysis of electromagnetic transients (EMTs) in the power system external to the WPP. The proposed model significantly reduces the computational resources and the simulation run time while preserving the WPP response fidelity in the desired frequency range, e. g., 0 to 50 kHz. The proposed WPP equivalent model is composed of two parts: 1) a frequency-dependent equivalent model which represents the WPP passive component in the entire frequency range and 2) a dynamic equivalent model that represents the WPP supervisory control and the aggregated low-frequency dynamics of wind-turbine generator (WTG) units. The latter can be constructed from the: 1) dynamic generic models; 2) vendor-specific models; or 3) user-defined models. The proposed model is incorporated as a software module in the PSCAD/EMTDC environment, and its efficiency and accuracy are verified based on comparing the results with those of a detailed model.