Analysis of static VAr compensators installed in different positions in electric railways

Abstract

With the power quality problems of electric railways becoming more and more serious, static VAr compensators (SVCs) have been widely used for power quality management. SVCs can be installed in the low-voltage side of traction substations, the high-voltage side of traction substations or the electric railway power supply side of substations. Different installation positions result in different compensation effects. In this study, characteristics of harmonic and negative sequence currents in the low-voltage and high-voltage sides of traction substations are analysed theoretically. Four schemes with SVCs in different installation positions are proposed. Then based on the measured datum and waveforms, simulation of each scheme is implemented, respectively, using PSCAD/EMTDC software. By comparing the compensation effects of the four schemes, the best SVC installation scheme in the low-voltage side of the traction substation is recommended for the measured traction substation. With SVC, the electric railway will have a less negative effect on the power grid. This study can also be applied to other SVC applications with non-linear loads, such as arc furnaces, rolling mills or electrochemical devices.

Design of RPFC for Power Quality Improvement in Railway Power System using Fuzzy logic Controller

“…As the popular PQ improvement rig, static var compensator (SVC) [9], [10], static synchronous compensator (STATCOM) [11]- [15], active filter [16]- [21], transformer integrated power conditioner [22]- [24], railway power flow controller (RPFC) [5], [25]- [30], and the well-designed train-mounted front end rectifier [31]- [33] are commonly used in ERPS. Considering the comprehensive performance, RPFC is concerned greatly by related departments due to its compatibilityit can, unlike the above rigs, integrate in the secondary side of almost all kinds of traction transformer.…”

“…Where, PLα and PLβ are the load's active power in phase α and β. It can be seen from (12), in light of the fact that Δα, Δβ can be pre-acquired for a specific sort of a transformer (e.g., the V/v transformer and other sort of the adjust transformers [35], [36]), μα and μβ are just dictated by PFA~PFC or φa~φc [see (10) and 2]. Henceforth, the active and reactive power of the RPFC can be adaptably balanced by controlling the primary three phase power factors, if the PFs of the two phase loads are pre-ascertained [see φLα and φLβ in (12)], which will be talked about later on.…”

“…The remunerating model of OCS can be controlled by the load point's area in the load distribution panel appeared in Fig. 5 or 7, which can be reasoned by distinguishing 4) If the repaying model is gotten from step 3, φa, φb, and φc can be figured from Table I and (13), so as μα and μβ [see (10)]. Consequently, the repaying active and reactive power of RPFC can be at long last gotten from (12), [note: in (12), φLα=arctan(QLα/PLα), φLβ=arctan(QLβ/PLβ)].…”

AC “Back to Back” Switching Device in Industrial Application

“…Flexible AC transmission systems (FACTS) is a wide area where SCRs are often used, particularly in Static VAR compensators (SVC) which are utilized in different sectors in electric power system (distribution and transmission lines/substations). Authors in [9] comprehensively reviewed the applications of SVC in different positions in electric railway systems. The evolution of SVC led to the development of static synchronous compensator (STATCOM), where in many topologies SCRs are still being used due to its economic benefits [10].…”

Development of an SDBC-MMCC-Based DSTATCOM for Real-Time Single-Phase Load Compensation in Three-Phase Power Distribution Systems

“…The operation principle of the Steinmetz compensator has been used in many applications of unbalanced load compensations [6]. Presently, static var compensators (SVC) are widely used in the load compensations of high-power, single-phase traction systems [7][8][9]. The thyristor-controlled reactor with fixed capacitor (TCR-FC) type of SVC is applied in these traction systems.…”