Sensing the Grid’s Invisible Forces An Electrical Sensor Assembly That Measures Power Line Fields With Exceptional Precision

A US power systems engineering company has patented a sophisticated electrical sensor assembly designed to accurately measure electric fields and power levels in high-voltage distribution systems – while shielding the sensitive sensing elements from outside interference. The invention’s layered architecture of sensors and screens within a tubular body provides grid operators with reliable, high-precision electrical measurements essential for safe and efficient power network management.

The Problem

Accurate measurement of electrical parameters – voltage, current, power and the electric fields associated with them – is fundamental to the safe operation of electrical power distribution systems. Utility operators depend on these measurements to monitor load conditions, detect faults, manage network switching and ensure that power is being delivered efficiently and safely to customers.

In high-voltage environments, making accurate electrical measurements is technically challenging. The very fields being measured can interfere with the sensing instrumentation – and other external electrical sources such as adjacent conductors, switchgear and electromagnetic interference from industrial equipment can corrupt measurements if not properly excluded. A sensor that picks up stray fields from outside the system under measurement will produce inaccurate readings, leading to poor decisions about network operation.

The challenge is designing a sensor that is sufficiently sensitive to detect the fields of the conductor it is measuring, while being robustly shielded from the external electromagnetic environment. This requires carefully controlled layering of sensing elements and shielding elements within a compact assembly that can be physically installed in a distribution system.

What This Invention Does

G & W Electric’s sensor assembly consists of a connecting bar running along a longitudinal axis, surrounded by a tubular body that is radially spaced from the bar – creating an annular space between the two. The tubular body contains a support member made of insulating material, and on this support member, the sensor architecture is built up in layers.

The first section of the tubular body carries the electric field sensor on its inner surface – facing the connecting bar – made from a layer of electrically conductive material. Adjacent to this, on the outer surface of the same section, sits the first electric screen – a second conductive layer that shields the sensor from external electrical interference. A second section of the tubular body, positioned adjacent to the first, provides an additional electric screen for further protection.

The entire assembly is enclosed in a dielectric material, providing electrical isolation and mechanical protection. This layered architecture – sensor on the inside, screen on the outside, with additional screening in the adjacent section – creates a well-controlled measurement environment that captures the field from the central conducting bar while rejecting external interference.

Key Features

Coaxial sensor and screen architecture. Placing the electric field sensor on the inner surface of the support member and the shielding screen on the outer surface creates an effective electromagnetic isolation that separates the measurement field from external interference.

Double screen protection. A second electric screen in an adjacent section of the tubular body provides a further layer of isolation, enhancing the rejection of external interference in particularly demanding electromagnetic environments.

Radially spaced tubular geometry. The annular space between the central connecting bar and the surrounding tubular body creates the physical separation needed to accurately measure the bar’s electric field without parasitic capacitive coupling.

Insulating material support structure. The use of an insulating material for the support member electrically isolates the sensor and screen layers from each other and from the surrounding structure, ensuring the measurement system behaves as designed.

Dielectric enclosure. Enclosing the tubular body in dielectric material provides additional electrical isolation and mechanical protection for the sensor assembly in the demanding environment of a power distribution installation.

Who Is Behind It?

G & W Electric Company is a US manufacturer of electrical power distribution equipment and components. The inventor is Alberto Bauer. This application is a divisional of AU 2019401573, claiming priority to Italian Patent Application No. 102018000011146 filed 17 December 2018 – reflecting the European origins of the sensing technology. The application is managed by Griffith Hack in Melbourne.

Why It Matters

Accurate, reliable measurement of electrical parameters is the foundation of intelligent power grid management. As electrical networks become more complex – integrating renewable generation, distributed storage and bidirectional power flows – the demands on measurement and sensing infrastructure increase. Equipment that can provide precise, interference-resistant electrical measurements in the field enables better fault detection, more accurate billing, improved load management and safer network operation.

For G & W Electric, which specialises in medium-voltage switching and protection equipment, a precision sensor assembly that can be integrated into distribution switchgear and cables extends the company’s product capability into the intelligence layer of the grid. With IPC classifications covering voltage and current measurement (G01R 15/14, G01R 15/16) and power measurement (G01R 21/00, G01R 21/06), the patent covers the core measurement functions that underpin power system monitoring and control.

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AU 2026201556 was published in the Australian Official Journal of Patents on 19 March 2026 and is open for public inspection. Patent applications represent inventions that are sought to be protected and do not necessarily reflect commercially available products.