Objective During morning and evening rush hours on weekdays, the frequent starting and braking of multiple trains in URT (urban rail transit) system may lead to strong fluctuations and high peaks in the power supply load. To mitigate the traction load as train enter/exit the depot during peak hours, it is necessary to study a peak load reduction technology for traction and power supply based on photovoltaic energy and energy storage devices.

Method An index is proposed for access point power self-consumption rate to evaluate the adaptability of photovoltaic energy. Taking a certain urban rail transit depot in Shanghai as an application case, based on the simulated current load data for peak load reduction, and the measured peak train enter/exit current data collected by this depot DC traction load monitoring system, the feasibility of the power supply peak load reduction technology is quantitatively verified on the power self-consumption rate basis.

Result & Conclusion  The peak load reduction technology for traction and power supply utilizes energy storage devices to store photovoltaic energy and release it timely during train entry/exit the depot, thereby effectively smoothing the peak load. Test results indicate that the maximum dynamic power self-consumption rate of the peak load reduction system can reach 15.8%, reducing the peak load during train entry/exit by 3% to 5%.