Dynamic Impedance Estimation: Challenges and Considerations

Mateus M De Oliveira,Renato R Aleixo,Paulo F Ribeiro,Rafael S Salles,Carlos A Duque,Leandro R M Silva,Denise F Resende

doi:10.3390/app11020558

Mateus M De Oliveira, Renato R Aleixo + Show 5 more

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https://doi.org/10.3390/app11020558

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Abstract

The objective of this paper was to examine the dynamic impedance estimation of electrical systems from online measurements. The paper makes several considerations and highlights the challenges to obtain a precise estimation. Transducer equalization and harmonic synchrophasor estimation (HSpE) are reviewed and discussed. The use of online and adaptive equalization for transducers proves to be a viable solution for improving voltage transducer’s (VT’s) and current transducer’s (CT’s) frequency response. Additionally, the use of oversampling algorithms can mitigate the effects of noise in the HSpE. Furthermore, methods for harmonic impedance estimation are discussed. The independent component analysis ICA-based dynamic impedance estimation is proposed and results presented, which yields excellent agreement. Finally, harmonic modeling and simulation of injected harmonic currents are used to observe resonances through the amplification and attenuations and, consequently, the opportunity to confirm the system self and transfer impedances of a test system. Dynamic impedance estimation will continue to be a great challenge for the power systems engineer as the system complexity increases with the massive insertion of power electronic inverters and the associated required filtering. Real-time signal processing will be an effective tool to determine the dynamic self or transfer impedance.

Highlights

Estimating the magnitude and phase of harmonics in electrical power systems (EPS)still presents significant challenges, mainly when we focus on medium voltage (MV)and high voltage (HV) systems and in dynamic scenarios
A,b, the present transfers values higher than the 1 for several frequencies. It means that harmonic sources injecting current at bus A or C can be amp frequencies
It means that harmonic sources injecting current at bus A or C can be amplified fied atatbus

Summary

Introduction

Estimating the magnitude and phase of harmonics in electrical power systems (EPS)still presents significant challenges, mainly when we focus on medium voltage (MV)and high voltage (HV) systems and in dynamic scenarios. Estimating the magnitude and phase of harmonics in electrical power systems (EPS). Still presents significant challenges, mainly when we focus on medium voltage (MV). High voltage (HV) systems and in dynamic scenarios. There are still limitations for these systems, given the complexity and costs of developing measurement equipment that meets the voltage levels and frequency range determined by standards [1,2]. The harmonic measurements performed in the secondary of the transformers do not faithfully represent the distortions present in the primary, limiting the analysis of harmonic propagation in MV and HV and their applications, such as: the identification and quantification of the harmonic sources responsibilities, the estimation of the electrical system parameters, the correlation of errors in the protection system with the power quality (PQ), among others

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Conclusion