Voltage fluctuation compensator for Shinkansen

Abstract

In AC electric railways, three‐phase voltage is changed into the single‐phase circuit of two circuits with the Scott‐connected transformer. If unbalancing of the load between single‐phase circuits becomes large, voltage fluctuation becomes large on the three‐phase side. Railway static power conditioner (RPC) was developed for the purpose of controlling voltage fluctuation on the three‐phase side. An RPC is comprised of a pair of self‐commutated PWM inverters. These inverters connect the main phase and teaser feeding buses, coupled with a DC side capacitor such as a back‐to‐back (BTB) converter. In this way, the two self‐commutated inverters can act as a static var compensator (SVC) to compensate for the reactive power and as an active power accommodator from one feeding bus to another. 20 MVA/60 kV RPCs started commercial operation in 2002 at each two substations on the newly extended Tohoku Shinkansen for compensating voltage fluctuation on the three‐phase side caused by traction loads, absorbing harmonic current. The results of operational testing indicate that an RPC can accommodate single‐phase loads such as those of PWM‐controlled Shinkansen and thyristor phase‐controlled Shinkansen, and handle the exciting rush current of transformers, as well as compensate for harmonics successfully. © 2007 Wiley Periodicals, Inc. Electr Eng Jpn, 162(4): 25–34, 2007; Published online in Wiley InterScience (http://www.interscience.wiley.com). DOI 10.1002/eej.20397

Applications of Triple Active Bridge Converter for Future Grid and Integrated Energy Systems

“…The AC power utility system for a railway, for example, shinkansen in Japan, uses two single-phase AC voltages 25 kV or 20 kV for two direction lines [70][71][72]. The single-phase AC voltages are supplied from a three-phase voltage using a Scott-connected transformer, as shown in Figure 23a.…”

“…This affects the three-phase voltage side, which causes a more significant voltage fluctuation. Therefore, a railway static power conditioner (RPC) is developed to control voltage fluctuation on the three-phase voltage side in [72], as shown in Figure 23b. An RPC is constructed from two pulse width modulation (PWM) inverters, which are connected by a large DC link capacitor system.…”

Hybrid Power Quality Compensation System for Electric Railway Supplied by the Hypotenuse of a Scott Transformer

“…Because in the compensation system, the tasks of active and reactive are performed by different devices separately, the reference current of T and M phase converter * , * could be written as (23) according to Fig. 6(b) and equation (6). The minus denotes the M converter is sending out the active power.…”

“…With the development of switching devices, the power quality problems caused by the nonlinear loads tend to be solved by the advanced power electronics technology. A railway static power conditioner (RPC) was proposed in [5], [6]. RPC was a pioneering innovation that excited many improvements in the traction power supply system later [7]- [18].…”