Electric Springs—A New Smart Grid Technology

TLDR

Hooke’s law described mechanical springs, but no extension to the electric regime has been developed. The authors develop electric springs, detailing their scientific principle, operating modes, limitations, and practical realization. Electric springs show great promise for stabilizing power systems with high renewable penetration, as demonstrated by effective voltage regulation in a wind‑fed test system and the potential to create smart loads that track generation, offering an ICT‑independent stability solution.

Abstract

The scientific principle of "mechanical springs" was described by the British physicist Robert Hooke in the 1660's. Since then, there has not been any further development of the Hooke's law in the electric regime. In this paper, this technological gap is filled by the development of "electric springs." The scientific principle, the operating modes, the limitations, and the practical realization of the electric springs are reported. It is discovered that such novel concept has huge potential in stabilizing future power systems with substantial penetration of intermittent renewable energy sources. This concept has been successfully demonstrated in a practical power system setup fed by an ac power source with a fluctuating wind energy source. The electric spring is found to be effective in regulating the mains voltage despite the fluctuation caused by the intermittent nature of wind power. Electric appliances with the electric springs embedded can be turned into a new generation of smart loads, which have their power demand following the power generation profile. It is envisaged that electric springs, when distributed over the power grid, will offer a new form of power system stability solution that is independent of information and communication technology.