Compensation of Voltage Drop using Static Var Compensator at Sectioning Post for Shinkansen Power Feeding System

Abstract

In Japan, the AC single phase electric railway system is adopted on main lines such as Shinkansen. The allowance range of feeding voltage for Shinkansen is 22.5-30kV.In recent years, the service load tends to increase with more frequent train operation, increased speeds and multiplied power. As the load capacity of train becomes larger, the reactive power of load causes a larger voltage drop. It is anticipated that the feeding voltage would drop below the lower limit of the allowance voltage range.With advance of power electronics technology, voltage drops in a feeding line and voltage fluctuations on the 3-phase side can be reduced, and the power factor at substations can be improved by compensating for the reactive power using a single-phase static var compensator (SVC).To compensate for voltage drops over AC feeding system, SVC should be located at the end of feeding circuit which is called sectioning posts. The capacity of SVC can be reduced to two-thirds by locating it at sectioning posts instead of substations. This paper describes the principle of voltage compensation using SVC with TSC installed at the sectioning post in San-yo Shinkansen and introduces the results of a site investigation.

Recent trends in power electronics applications as solutions in electric railways

“…PE applications to the AC traction power supply system in Japan was started in 1987 when SVC (static var compensator) by thyristors was installed at Aomori SS on Tohoku Line for voltage fluctuation suppression, improvement of power factor, and voltage drop compensation, preparing for operations in the Seikan Tunnel of 53.85 km length. After that, some applications were discussed and systems installed for stabilization of the AC traction power supply system in Japan . Table shows a summary of previous cases of PE applications on Tokaido Shinkansen .…”

Voltage Fluctuation Compensator for Shinkansen

“…All companies of the JR group use for this purpose single-phase SVRs (line-commutated) installed at sectioning posts (SP) [11]. In this case, the former substation becomes a feeding circuit terminal.…”

“…If an RPC is installed at this substation, the reactive power required to compensate for the voltage drop can be calculated by detection of the terminal voltage. All companies of the JR group use for this purpose single-phase SVRs (line-commutated) installed at sectioning posts (SP) [11].…”