Switching power supply starting circuit of medium-voltage contactor

Abstract

The invention relates to a switching power supply starting circuit of a medium-voltage contactor. The circuit comprises an input commutator circuit, a voltage stabilizing sub-circuit, a quick startingsub-circuit, a restarting sub-circuit, a control chip, a high-frequency coil and a protection control module which are arranged in sequence, one end of a primary winding of the high-frequency coil isconnected with a first output end of the input commutator circuit, and the other end is connected with the control chip; one end of the auxiliary winding is connected with the restarting sub-circuit,the other end of the auxiliary winding is connected with the second output end of the input commutator circuit and grounded together with the second output end of the input commutator circuit, and the protection control module is connected with the control chip and a secondary winding of the high-frequency coil. Compared with the prior art, the switching power supply starting circuit has the advantages of the high starting speed, high reliability and the like.

Description

technical field [0001] The invention relates to the field of medium-voltage contactors, in particular to a starting circuit for a switching power supply of a medium-voltage contactor. Background technique [0002] Medium-voltage contactors are used in three-phase systems with rated voltage below 12KV and rated 50 / 60Hz. As a kind of electrical protection equipment, they are especially suitable for the protection of electrical equipment such as motors, transformers, and capacitor banks. They are widely used in the power industry, In the fields of industrial and mining enterprises, petrochemical industry, papermaking and metallurgy, etc., special control methods are required for the pull-in and disconnection of contactors. Commonly used contactor controls include magnetic hold, electric hold, and mechanical hold. [0003] With its outstanding advantages of energy saving and flexible control, the electric holding module is widely used in the control of medium voltage contactors....

AI Technical Summary

Problems solved by technology

[0007] 1) Due to the start-up mechanism of the switching power supply, the existence of the charging and discharging time of the resistor R1 and the capacitor C1, the power-on time of the system cannot meet the requirements of fast startup;

[0008] 2) The start-up time of the power supply can be improved by removing the resistor R1 and the capacitor C1, but the system will lose the protection function and reduce the stability of the system;

[0009] 3) The startup time of the power supply can be reduced by reducing the value of resistor R1 and capacitor C1, but the value of resistor R1 is at the MΩ level to ensure a wide voltage input range. Capacitor C1 also has the function of filtering the power supply ripple of the auxiliary winding. Reduction in limit reduces reliability

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