Pre-charging circuit

Abstract

A pre-charging circuit comprises a power supply switch (11), a drive switch circuit (14), a switch circuit (12), an input power supply (10), an internal circuit (13), and a charging circuit (15); The first output end of the input power supply is connected to the first end of the power supply switch, The second end of the power supply switch is connected to the first end of the switch circuit and the first end of the internal circuit, The second end of the switch circuit is connected to the second end of the input power source and the first end of the drive switch circuit, The third end of the switch circuit is connected to the second end of the drive switch circuit, The third end of the driving switch circuit is connected to the second end of the internal circuit and the first end of the charging circuit, The fourth end of the driving switch circuit is connected to the second end of the charging circuit, The third end of the charging circuit is connected to the second end of the input power source; The input power is used to charge the internal circuit through the power switch and the charging circuit when the power switch is closed. The pre-charging circuit can avoid current impact when the equipment is connected to the high-voltage system.

Description

technical field [0001] The present application relates to the field of electrical technology, in particular to a precharging circuit. Background technique [0002] In recent years, with the development of new energy vehicles, new energy vehicles have become an emerging strategic industry in the country. In the interior of the car, there is a high-voltage DC system. The system is equipped with a high-voltage DC input power supply and many high-voltage electrical equipment. The input ports of these electrical equipment will be equipped with capacitors for filtering. However, before the electrical equipment is connected to the high-voltage DC system, the voltage of the capacitor is zero. At the moment when the electrical equipment is connected to the high-voltage DC system, a huge inrush current will be formed due to the extremely high voltage difference between the inside and the outside, which will not only bring the entire system The impact of the surge current, at the same...

AI Technical Summary

Problems solved by technology

However, before the electrical equipment is connected to the high-voltage DC system, the voltage of the capacitor is zero. At the moment when the electrical equipment is connected to the high-voltage DC system, a huge inrush current will be formed due to the extremely high voltage difference between the inside and the outside, which will not only bring the entire system The impact of the surge current, at the same time, the surge current will also cause damage to the power switch of the electrical equipment

[0003] In order to improve this phenomenon, a pre-charging circuit is usually added to protect the power supply switch. In a common high-voltage DC system, a pre-charging circuit is connected in parallel at both ends of the power supply switch. The pre-charging circuit contains a relay. This pre-charging circuit Although the circuit can protect the power supply switch, the relay needs a special control circuit to close, which leads to a complicated circuit structure. At the same time, the size of the relay is relatively large, which is not conducive to the overall layout.

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