Slow start control method for high-power direct-current converter with high step-up ratio

The invention relates to the technical field of direct-current step-up collection systems, and particularly relates to a slow start control method for a high-power direct-current converter with a highstep-up ratio. When a main inverter detects that the voltage of the DC side of the main inverter reaches a voltage value allowing the start, the main inverter/slave inverters starts/start to output voltage for open-loop slow start, then the main inverter enters a closed-loop operation state, then the slave inverter 1 enters a closed-loop slow start state, and the other slave inverters sequentially perform closed-loop slow start according to the closed-loop slow start mode of the slave inverter 1; and after the closed-loop slow start of all the slave inverters succeeds, the main inverter performs direct-current side voltage outer-loop slow start again, and the slow start is ended. According to the method, the impulse voltage and the impulse current appearing in the starting process of thehigh-power direct-current