In order to reduce the adverse effects of installation space and magnetic saturation of the step-down transformer on the engineering application and governance effects of railway static power conditioner（RPC）

the railway static power conditioner of modular multilevel converter（MMC-RPC） has become a research hotspot. However

the existing MMC-RPC control strategies do not consider the influence of the actual load power and current fluctuation characteristics of electric locomotives on the capacitance voltage of each sub-module of MMC

so that the capacitor voltage fluctuates greatly. Therefore

according to the power and load characteristics of electric locomotives

a hybrid PWM modulation strategy is adopted

which can not only meet the requirements of low switching loss

but also adapt to the fluctuation range of the capacitor voltage equalization of each sub-module of MMC-RPC under the dynamic operating characteristics of electric locomotives. Finally

the simulation and experimental results verify the superiority of the MMC-RPC output performance over the traditional two-level RPC. By adopting the hybrid PWM modulation strategy

the MMC-RPC can adapt to the actual load power and current fluctuation characteristics of electric locomotives

and the fluctuation amplitude of the capacitor voltage equalization of each sub-module is effectively controlled within the range of ±5%.