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Micro Substation Demonstration Project Using a Power Voltage Transformer (PVT): Results Presentation Held in India —The system’s stable operation and usefulness proven on-site—

Nissin Electric Co., Ltd. has completed the project “Demonstration Research on Micro Substations to Realize Power Supply with Low Environmental Impact in Areas with Underdeveloped Power Distribution Networks (India),” which has been subsidized by the New Energy and Industrial Technology Development Organization (NEDO). A results presentation was held in New Delhi on March 11, with numerous stakeholders from Japan and India in attendance.
In this demonstration research, a micro substation*¹ equipped with a power voltage transformer (PVT) *² was introduced at a substation on the outskirts of Delhi owned by the local distribution company, TATA Power-Delhi Distribution Limited. The system was then used to supply power to the surrounding area, verifying the reliability of power supply to consumers and the effectiveness of the system. (Demonstration operation period: June 2025 to March 2026)

[Overview of the micro substation]
This system utilizes a PVT to directly convert power from high voltage transmission lines to low voltage power, enabling a stable power supply to a small settlement (100 kVA or less). It reduces equipment and operating costs as compared with conventional power supply systems, such as substations and diesel generators.

[Summary of research findings]

1. Proven reliability of the power supply
   The system has continuously supplied power at a stable voltage without deviating from the specified voltage range under different operating conditions than in Japan. In addition, it has been confirmed that normal operation was promptly resumed after restoration from a voltage dip*³ or blackout in the power grid. Thus, the system will ensure a stable power supply even under high temperatures, high humidity, and diverse environmental conditions.
2. Improved usability due to simple equipment configuration
   In this demonstration research, we confirmed that the micro substation connected to the current power grid operates within the specified voltage range simply through secondary voltage (turns ratio) adjustment made during PVT fabrication, without the installation of a voltage stabilizer. This allows for a reduction in equipment costs and an improvement in system efficiency.

Results presentation held in India

Rendered image of power supply by the micro substation

The micro substation will continue to operate at the site in India even after the demonstration research is completed. The results of this demonstration research will be used to commercialize the project in areas where the grid is non-existent that face challenges such as installation and operation costs and installation locations (region and space).

Reference

[Terminology]

*1　 Micro substation

A substation that directly obtains low-voltage electricity of about 10 to 100 kVA from high voltage transmission lines of 66 kV or more by using a PVT, which applies voltage measurement transformer technology, with increased electricity supply capacity.

*2　 Power voltage transformer (PVT)

A voltage transformer that can supply power by directly converting high voltage to low voltage by applying voltage transformer (VT) technology used to convert high voltage to low voltage for the measurement of high AC voltage. Nissin Electric is the only company in Japan that manufactures PVTs.

*3　Voltage dip

A phenomenon in which voltage temporarily drops due to factors related to power grids and the like.