Shunji Tokuyama

Title: Shunji Tokuyama: Innovator in Circuit Breaker Technology

Introduction

Shunji Tokuyama is a prominent inventor based in Hitachi, Japan. He has made significant contributions to the field of electrical engineering, particularly in the development of advanced circuit breaker technologies. With a total of 5 patents to his name, Tokuyama's work has had a lasting impact on the industry.

Latest Patents

One of Tokuyama's latest inventions is a grounding switch gear device. This device features a first puffer chamber formed by a puffer cylinder with a cylindrical flange portion and a shaft portion, along with a fixedly disposed piston. The piston is designed in a cylindrical shape, sealed from external space, and is accommodated in the flange portion of the puffer cylinder at the circuit breaking position. The internal space of the piston serves as a second puffer chamber, which communicates with the first puffer chamber. This design allows gas accumulated in the second puffer chamber to be continuously blown out between the electrodes, effectively prolonging the interruptable arc time span without increasing the size of the circuit interrupting unit and operating unit.

Another notable patent is the DC circuit breaker, which is a line voltage charging type designed for use in DC transmission. This circuit breaker includes a series circuit connected in parallel with a commutation breaker, consisting of a capacitor charged by line voltage, a reactor, and a circuit-closing means. The DC circuit breaker features a circuit for charging the capacitor, which includes a current direction restricting circuit that allows current to flow in only one direction, along with a reverse control circuit to manage the current direction for charging the capacitor based on power flow reversal control.

Career Highlights

Tokuyama has dedicated his career to advancing electrical engineering technologies. His innovative designs have not only improved the efficiency of circuit breakers but have also enhanced safety measures in electrical systems. His work at Hitachi, Ltd. has positioned him as a key figure in the development of cutting-edge electrical solutions.

Collaborations

Throughout his career, Tokuyama has collaborated with notable colleagues, including Keiji Arimatsu and Yoshio Yoshioka. These partnerships have fostered a creative environment that has led to the successful development of various innovative technologies.

Conclusion

Shunji Tokuyama's contributions to circuit breaker technology exemplify his commitment