Abstract

Unbalanced power causes loss of the propulsion motor of railway vehicles, and increase in temperature shortens the service life of electric vehicles. Not only this, it also increases the cost of electricity and maintenance. In the past, the industry focused only on methods to improve power quality such as load capacity, relay setting, and harmonic resolution. Now, they consider Three-Phase Unbalance Rate (TPUR). The paper proposes Special Transformers Wiring (STW) to improve the three unbalanced rates and provide different transformer wiring methods. According to the IEEE Committee, in the future, power companies will need to install balanced relay stations to improve three-phase unbalanced rate. The internal regulations of Taipower must be less than 4.5% (voltage unbalance rate of 2.5% and motor temperature rise of 12.5%). The derivation of the transformer "three-phase unbalance rate" model is the focus of the railway system. This study is based on the model derivation of different wiring methods to improve the heat problem caused by the three-phase unbalance and improve the service life of the train. A comparison is made with Scott, Le-Blanc and Modified-Woodbridge three wiring methods in railway system routes to improve the three-phase unbalance rate, in line with the IEEE standard of less than 2%.

Introduction

The derivation of the transformer "Three-Phase Unbalance Rate (TPUR)" model is the focus of the railway system. In the past, railway system often focused on the improvement of harmonic pollution, but ignored the existence of three-phase unbalance. This study is based on the model derivation of different wiring methods to improve the hot problem caused by the three-phase unbalance (Liu et al., 2020) and improve the service life of the

Keywords

Three-Phase Unbalance Rate (TPUR), Negative Phase Sequence Unbalance Rate (NPSUR), Special Transformer Wiring (STW), Railway System Transport Cable (RSTC), Traction Supply Substation (TSS)