Pre-charging control system applied to rail traffic air conditioning frequency conversion system

Abstract

The invention provides a pre-charging control system applied to a rail traffic air conditioning frequency conversion system and belongs to the technical field of pre-charging of rail transit air conditioning frequency conversion systems. The pre-charging control system includes a pre-charging module connected with an input power supply, a mating control module and a detection module. The rail traffic air conditioning frequency conversion system is formed by a capacitor module and a frequency conversion module which are connected in series sequentially, and the input end of the rail traffic airconditioning frequency conversion system is connected with the pre-charging module. The pre-charging module includes a diode D1, a charging resistor R1, a contactor CT2 and a contactor CT1, wherein the diode D1, the charging resistor R1 and the contactor CT2 are arranged in series on a DC bus, and the contactor CT1 is in parallel connection with the diode D1, the charging resistor R1 and the contactor CT2. The opening and closing of the contactor CT1 and the contactor CT2 are controlled by a control module. The detection module is arranged at the input end of the frequency conversion module,and the output end of the detection module is connected with the control module.

Description

technical field [0001] The invention belongs to the technical field of precharging of rail transit air conditioner frequency conversion systems, and in particular relates to a precharge control system applied to rail transit air conditioner frequency conversion systems. Background technique [0002] At present, the pre-charging control system of the existing rail transit air-conditioning frequency conversion system, such as image 3 Shown: When the input power is turned on, the contactor CT1 is disconnected, and the capacitor module is charged through the charging resistor R1; when the detection module detects that the bus voltage value is greater than the set threshold, the control module controls the contactor CT1 to pull in and charge the capacitor module. Resistor R1 is short-circuited to end pre-charging. Since the input power voltage range of rail transit air conditioners is wide, such as DC450V-DC900V, the set threshold should be at least not greater than the minimum ...

AI Technical Summary

Problems solved by technology

Since the input power voltage range of rail transit air conditioners is wide, such as DC450V-DC900V, the set threshold should be at least not greater than the minimum voltage of DC450V, but if the set value is DC450V, and when the input voltage is DC900V, if the bus voltage reaches DC450V Immediately after connecting the contactor CT1, since there is still a voltage difference of 450V between the input voltage and the current bus voltage, a large inrush current will still be generated, even up to hundreds of amperes, which seriously affects the power safety of the rail transit air-conditioning inverter system

Images