Most utilities still maintain a large inventory of legacy (40+ years) transformers that are still in-service with their original supplied OIP bushings. Because of the standards and generous margins used in the design and construction of these older transformers, these transformers continue to provide reliable service. However, it is well known that over time dielectric […]

RHM International announces the successful type test of a major innovation: HV_DryShield® Capacitor Voltage Transformer (CVT). The first ever HV dry type CVT WITH NO OIL, NO GAS. Leaning on the expertise of our established patented HV_DryShield® dry insulation technology, RHM International has completed the development of the first dry type, paperless high voltage Capacitor […]

In the 1990’s a new type of dry insulation technology made of synthetic materials was introduced in China for high-voltage current transformers. This technology used no oil or gas and no paper, instead using PTFE (PolyTetraFluoroEthylene) film as the main insulation for the primary condenser core. PTFE is an excellent electrical insulation material with an […]

In a recent CIGRE publication the loss of a single phase GSU transformer due to an HV bushing turret rupture was discussed. In this case an OIL/SF6 RIP bushing failed catastrophically inside its turret which led to the rupture of the turret and the loss of a multi-million-dollar transformer from the resultant fire. Transformer manufacturers […]

RHM International recently attended the CIGRE Canada 2023 conference in Vancouver, British Columbia which was held from September 25th to 27th, participating as an exhibitor while also presenting a technical paper titled “New Dry Type Insulated Products for Your IEC 61850 Digital Substation.” We are proud to announce that our paper was selected second best […]

In the August 2023 issue of Corporate Vision magazine, RHM International was recognized as one of the outstanding organizations in the world of business as a developer of innovative, high-voltage and extra high-voltage dry type insulated products for the global power transmission industry. These innovative products offer the power industry dry type alternatives to oil […]

In late 2023 the first BIIT™ bushings will be delivered to a large state-owned utility in Europe. These bushings were ordered with the following technical parameters: Maximum voltage of equipment：170 kV Rated Line to ground：98 kV Rated frequency：50Hz Rated Current Ir：1600 A Rated lightning impulse withstand voltage 1.2 / 50μs：550 kV Rated power frequency withstand […]

A recent generation of dry type insulation technologies has changed the economics for real-time insulation condition monitoring. This article discusses integrated condition monitoring solutions that can be built into the primary condenser cores of transformer bushings, current transformers and cable accessories (terminations and joints). These solutions include monitoring of capacitive current in the primary condenser […]

In 2015 two 230 kV RIF® bushings were seismically qualified by shake table testing according to IEEE 693-2005. This testing was performed at the Structural Engineering & Earthquake Simulation Laboratory (SEESL) at the University of Buffalo. The test samples were two identical 230 kV RIF® bushings. One bushing was tested for the normal IEEE 693-2005 […]