TCMS-based Dual-bus Grid-connected Power Supply Control Technology Scheme for Metro Train Auxiliary Power Supply System

Abstract

Objective In the current mainstream of train auxiliary power supply systems, such as cross-supply method and extended supply method, the failure of a single SIV (auxiliary inverter) can impact the normal operation of electrical equipment on the train. As an emerging control technology, the grid-connected power supply has its advantages and requires in-depth research into its control technology. Method Taking Shanghai Rail Transit Line 8 as example, issues related to slow response and low reliability in the auxiliary power supply system for the third batch of purchased train are addressed. For the design of the fourth batch of purchased trains, a dual-bus grid-connected power supply scheme based on TCMS (train control and management system) control is proposed. Specifically, four TLKs (grid-connected contactors) are arranged in the middle car to link four independent medium-voltage buses together. The medium-voltage bus structure of the auxiliary power supply system under this scheme is introduced, the action sequence during the internal start-up stages and grid-connected start-up stages of SIV are analyzed, and the logics of grid-connected power supply control, SIV start-up and fault protection are expounded. Result & Conclusion The time required for grid-connected power supply in the proposed scheme is significantly reduced (minimum of 2.5 seconds). The medium-voltage bus topology with dual-bus and multiple TLKs avoids system functionality overall failure due to bus short-circuits, improving the reliability of train auxiliary power supply system. The grid-connected power supply technology based on TCMS control is expected to be a development direction of auxiliary power supply technology for urban rail transit trains in the future.

Keywords

• metro
• train auxiliary power supply system
• auxiliary inverter
• dual-bus grid-connected power supply