## 1 Introduction
For this reason, in this research a flexible extended harmonic domain (FEHD) technique together with the Time-Domain (TD) are interfaced to produce a hybrid TD/FEHD, which is used to model a synchronous-based wind turbine generator. The obtained results are validated with PSCAD EMTDC(r) and are verified with experimental data, revealing a very good agreement [27]. Finally, a study was published regarding the power converters used for coupling wind turbines to the electrical grid. This study analyzed the generation of high frequency harmonics under the influence of controllers. In this addition, this article studies the relationship between the output and the harmonic source at grid-side and rotor-side converters based on their control features in the DFIG system. The effectiveness of the proposed model is verified through the 2 MW DFIG real-time hardware-in-the-loop test platform by StarSim(r) software and real test data, respectively [28]. After analyzing the specialized literature, it is concluded that work has been carried out for the harmonic analysis of wind turbines connected to the electrical grid. However, they do not consider the impact of high-order inter-harmonics on the system. So, the research in this article presents a clear model analysis of frequencies generated by the DFIG for the harmonic and non-harmonic analysis of the DFIG connected to the electrical grid. This investigation is powered by exploiting the frequency-domain harmonic analysis and by considering the impact of the high frequency components on the power quality system. Similarly, wind power plants, like all other sources of electricity generation, should contribute to maintaining the stable grid under any operating condition. The major contributions of the paper are pointed out below:  
1. This analysis provides a complete model of the DFIG steady-state operation that is directly applicable to the load flow analysis. It allows a complete knowledge of the steady-state operation condition of a DFIG considering the wind speed as input value. 2. Considering the attained results from the load flow analysis, a model of the DFIG steady-state operation in the harmonic domain is completed; this model adopts the sum of both effects in each voltage source, that is, both the stator and the rotor, for obtaining a complete solution for a DFIG. 3. By setting up an experimental test, the obtained results for the proposed model in the steady-state and transient-state of the DFIG under non-sinusoidal voltage conditions are validated with those resulting from the hardware implementation, demonstrating the effectiveness of the model presented. 4. Furthermore, this analysis provides a clear analysis of the frequencies generated by the DFIG in the steady-state resulting in a complete and proper model for harmonic and non-harmonic analysis of the DFIG connected to the electrical grid. This paper is structured as follows. In Section 2, the model of a DFIG and its analysis at a fundamental frequency is described. A DFIG-based load flow analysis is addressed in Section 3. In Section 4, the DFIG complete solution for harmonic propagation is derived. A topology of the B2B power converter for grid connection purposes is described in Section 5. In Section 6, the results obtained with the proposed model made in MATLAB-Simulink(r) are validated by matching those obtained from real lab measurements and with a complete induction machine model for transient studies. Finally, concluding remarks are given in Section 7.