氢能与弓网并联供电系统的无缝切换控制方法

Control method for seamless switching in hydrogen energy and pantograph-catenary parallel power supply system

氢动力机车的氢能系统在并/离网切换时存在暂态过程,影响切换效果。文章提出了一种氢能与弓网并联供电系统的无缝切换控制方法。该方法将氢能供电侧Boost变换器并网状态与离网状态下的受控功率目标相联系,制定了Boost变换器统一功率指令配置策略,可实现Boost变换器受控功率目标对氢能与弓网供电系统并/离网状态的自适应调节,进而保证了并联系统的直流母线电压的稳定。该方法无需检测弓网侧AC/DC变换器状态,实现了氢能供电侧Boost变换器在并/离网控制状态下的平滑切换。通过分析下垂系数、直流母线电压和最小受控功率目标的关系,给出了氢能供电侧Boost变换器的最佳下垂系数设计方法。最后进行了RTLAB硬件在环试验,验证了所提方法在不同负载工况下稳定直流母线电压和实现氢能系统并/离网状态的平滑切换的有效性。

In order to eliminate the transient process of the hydrogen energy system of the hydrogen power locomotive upon switching between the grid-connected and standalone control modes,a seamless switching control approach for the hydrogen energy and pantograph-catenary parallel power supply system was proposed in this paper.With the control power targets of the Boost converter on the hydrogen power supply side in the grid-connected and standalone states interrelated,a unified Boost converter power command configuration strategy was established,which could realize the self-adaptive adjustment of the control power targets of the Boost converter to the grid-connected and standalone states of the hydrogen and pantograph-catenary power supply system,ensuring the DC bus voltage of the parallel system stable.Moreover,without detecting the state of the AC/DC converter on the pantograph-catenary side,smooth switching of the Boost converter on the hydrogen power supply side could be realized between the grid-connected and standalone states.The optimal droop factor design approach for the Boost converter on the hydrogen power supply side was then proposed by studying the relationship among the droop factor,the DC bus voltage and the minimum control power target.The proposed method was is verified by RTLAB hardware-in-the-loop tests.The results show the method is effective in stabilizing the DC bus voltage and realizing seamless switching of the hydrogen energy system between the grid-connected/standalone states under different load conditions.