New technologies, grid resiliency and sustainable power: it is also a matter of electrical apparatus reliability

Abstract

New technologies for generation and T&D may have deep impact in the power quality, resiliency and sustainability of electrical networks. The progressive, and rapid in some Countries, introduction of massive renewable resources, DC and hybrid DC/AC transmission, power-electronic controlled loads, and the increase of voltage rating of power electronic devices is going to break the axiom that power supply in electrical assets is sinusoidal AC. Emphasis is, therefore, in understanding the major problems caused by the massive introduction of new conversion technologies on grid component reliability, then to adequate the design of electrial apparatus to the quality and type of power supply. This paper focuses on life and reliability of electrical insulation, being insulation, in general, the weakest part of an electrical apparatus or device. Models to account for electrical and thermal overstresses caused by deviation from AC siuusoidal waveforms are presented in the paper, accounting for repetitive or random voltage transients, DC voltage plus ripple, harmonic voltages and currents. Application examples are discussed, to leverage the potentially dramatic effect on insulation reliability of a new, non AC-sinusoidal, paradigm of electrical grid and asset.