Confirmation test in refurbishment of the control and protection system devices and thyristor valve modules in the 300 MW Shin-Shinano No.2 frequency converter

(BTB) frequency converter system and started operation in May 1992.

Due to the discontinuation of component supply, the manufacturer’s maintenance support period for the control and protection (C&P) system devices and related equipment of this system has expired. If a malfunction occurs in the C&P system devices or related equipment of ShinShinano No. 2 FC, it will be difficult to secure identical or alternative parts, which could result in the FC becoming inoperable. Therefore, a comprehensive renewal of these devices was undertaken to maintain equipment reliability.

Multiple incidents of water-cooled resistor burnout occurred in the thyristor valve module due to deterioration of component materials over time, resulting in emergency shutdowns of the No.

2 FC. In response, a partial renewal targeting both the C&P system devices and the thyristor valve modules was implemented.

This project involved various tests to verify the integration of the C&P system devices from different manufacturers at each terminal, as well as functional validation of the partially renewed thyristor valve modules. Commercial operation commenced in December 2024.

This paper presents the characteristics and results of the tests conducted during the renewal of the C&P system devices and thyristor valve modules for Shin-Shinano No. 2 FC.