A novel collaboration compensation strategy of multi railway power conditioners under V/V electric traction system

A novel collaboration compensation system based on the railway power conditioner (RPC) is proposed in this paper. This negative sequence compensation system is used to eliminate negative sequence current for the high-speed railway traction power system with a three-phase V/V traction transformer. The minimum installed capacity is conducted which is 1/3 smaller than traditional single station compensation. This paper comes up the control strategy for every RPC device under different working conditions. A novel control system based on dual-loop control is adapted. Simulation results have confirmed that the compensation system proposed in this paper can achieve good performance at the negative sequence compensation with a small capacity and low cost.

I. Introduction

Railway transportation plays a very important role in transportation system. High-speed railway will be the future for electrified railways. Modern railway locomotive load has some characteristics such as big instantaneous power, high power factor, low harmonic components and high negative sequence component [1]–[3]. A large amount of negative current is injected into grid [4], which causes serious adverse impacts on the operations of generation, transmission, and distribution equipment in the power grid. These adverse impacts threaten the safety of high-speed railway traction supply system and power system. Therefore, it's necessary to take measures to suppress negative current.