News Releases 2020A new 6 kV solid-insulated switchgear (Smart SIS) for distribution substations completed
First unit delivered to TEPCO Power Grid Inc.

Meidensha Corporation (Meiden) is pleased to announce the completion of a new 6 kV solid insulated switchgear*1 (smart SIS) and the delivery of the first unit to TEPCO Power Grid Inc. in March 2020. This new product will mainly be installed at distribution substations operated by power utilities, and will play a role in supplying electricity through 6kV distribution lines and help to rapidly recover from accidentsfaults.

Many of the SIS units in Japan were installed in the 1980s and have been in use for about 40 years. As time passes these units experience equipment failures along with rusting and corrosion of the chasis. Some are now needing to be replaced. In addition, there is growing demand for equipment that can be managed by small crews and that has diagnostic functions employing IoT technology.

To meet these needs, in 2017 Meiden began developing the new SIS with a lower price point*2 than conventional units*3.

Smart SIS features

1. Structural optimization that meets relaxed specifications
Due to relaxed specifications, compared to Meiden's previous products the Smart SIS has a smaller and simpler operating mechanism that uses less energy. In addition, it has a shorter isolating distance in the mobile portion and a smaller vacuum valve.
Cost savings were also achieved by integrating the protection-control device, which had a separate panel layout in previous units, with the main SIS body.

2. Constant monitoring of equipment status with IoT tech
The Smart SIS has various sensors in the panels and protection-control devices, and their measurements are used to constantly monitor the functional status of the equipment. This reduces clients' regular patrols and inspections, helping to save labor and optimize inspection schedules.

3. Application of IEC 61850
Digital transmissions between the Smart SIS and remote supervisory-control equipment (TC) are in accordance with IEC 61850. Previous Meiden units used numerous control cables to connect with TC, but the Smart SIS uses anoptical cable, which greatly reduces the amount of work needed to lay cable and the time required for checks and testing. In addition, conforming to IEC 61850 means the unit can be connected to TC of other firms.

Meiden's Smart SIS was developed to replace the conventional SIS currently in use by power companies to meet expected future demand for equipment and parts updates.

*1 Solid insulated switchgear (SIS) uses epoxy mold solid insulation covered by an earthed layer on all live parts.
*2 Compared to other Meiden products.
*3 Product specifications are based on a request for proposal (RFP) from TEPCO Power Grid Inc. which has relaxed specifications compared to conventional units.

Smart SIS external appearance



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