基于超级电容的交直交牵引供电系统及控制策略

针对传统电气化铁路中无功、谐波、负序等电能质量问题和电分相问题,并考虑牵引负荷的冲击性,提出一种由多端口交直交(AC/DC/AC)变流器、牵引变压器及超级电容储能构成的牵引供电系统及控制策略.牵引变压器的二次侧分别通过两个整流端口与变流器中的单相整流器相连,将整流器的直流母线并联引出,变流器的逆变端口连接在牵引网上;超...

Research on AC-DC-AC Traction Power Supply System Based on Super Capacitor and Control Strategy

Aiming at power quality problems such as reactive power, harmonics, negative sequence current, and the problems of neutral sections in traditional electrified railways, and considering the impact of traction load, a traction power supply system and control strategy composed of multi-port AC-DC-AC converters, traction transformers and super capacitor energy storage are proposed in this paper. The secondary side of the traction transformer is respectively connected to the single-phase rectifier in the converter through two rectification ports, the DC bus of the rectifier is led out in parallel, and the inverter port of the converter is connected to the traction network; the super capacitor is connected in parallel to the DC bus through the Buck/Boost converter. The rectifier adopts dual-loop control of DC voltage outer loop and grid-side current inner loop, which stabilizes the DC bus voltage while solving power quality problems. The output-side inverter adopts the voltage effective value outer loop, and the instantaneous value inner loop to control the amplitude and phase of the output voltage, which can completely eliminate the electrical phase separation. According to the system capacity and the power of the traction load, the charging and discharging thresholds of the super capacitor are determined, the reference current value of charging and discharging is calculated, and the charging and discharging of the super capacitor are controlled to stabilize the fluctuation of the output power of the grid. A simulation analysis was carried out in MATLAB/Simulink to verify the feasibility of the scheme.